WO2015066929A1

WO2015066929A1 - Method and device for selecting wireless access network

Info

Publication number: WO2015066929A1
Application number: PCT/CN2013/086886
Authority: WO
Inventors: 潘甦; 舒文江
Original assignee: 华为技术有限公司
Priority date: 2013-11-11
Filing date: 2013-11-11
Publication date: 2015-05-14
Also published as: CN104429131A

Abstract

Provided in an embodiment of the present invention are a method and device for selecting a wireless access network, the method comprising: acquiring the bit error rate requirement of a service and the load conditions of a plurality of wireless access networks; according to the bit error rate requirement of the service and the load conditions of the plurality of wireless access networks, estimating available transmission rates of the service upon the access of the service respectively via the plurality of wireless access networks; and according to the available transmission rates, selecting one of the plurality of wireless access networks for the service so as to enable the service to access the selected wireless access network. The technical solution of the present invention enables a selected wireless access network to satisfy the network load balancing requirement and the bit error rate requirement of a service, thus selecting a proper wireless access network for the service.

Description

Method and device for selecting a wireless access network

Embodiments of the present invention relate to the field of communications, and more particularly to a method and apparatus for selecting a wireless access network. Background technique

In the scenario of multiple radio access network coverage, each radio access network adopts its own access model and radio resource management strategy. This separate mode of operation is not conducive to the full utilization of increasingly tight wireless resources (eg, bandwidth). Therefore, with the rapid development of multi-mode terminal technology and heterogeneous network collaboration technology, resource convergence of heterogeneous wireless networks is an inevitable trend in the development of wireless communication networks in the future. To this end, a Common Radio Resource Management (CRRM) solution has been proposed. In a heterogeneous network environment with multiple radio access technologies, a plurality of different radio access networks are collectively covered in the same area for the multimode terminal to access the communication network.

At present, a scheme for selecting a radio access network based on a Signal to Interference and Noise Ratio (SINR) has been proposed, which selects an access radio access network according to the SINR of different radio access networks. However, the SINR is typically maintained at a certain level by power control in a particular network. Since the SINR levels of the two radio access networks are the result of power control, it is not appropriate to use the difference in SINR between the two networks as a radio access network selection criterion. Summary of the invention

Embodiments of the present invention provide a method and apparatus for selecting a wireless access network that is capable of selecting a suitable wireless access network for a user equipment.

In a first aspect, an embodiment of the present invention provides a method for selecting a radio access network, including: acquiring a bit error rate requirement of a service and a load condition of multiple radio access networks; and determining a bit error rate according to the service. And estimating, by the load conditions of the plurality of radio access networks, an available transmission rate when the services are respectively accessed by the multiple radio access networks; according to the available transmission rate, from the multiple radios A wireless access network is selected for the service in the access network to access the selected wireless access network.

With reference to the first aspect, in a first possible implementation manner, the estimating, according to a bit error rate requirement of the service, and a load condition of the multiple radio access networks, The available transmission rate of the radio access network, including: estimating, according to the error rate requirement of the service, the load condition and the interference condition of the multiple radio access networks, The available transmission rate when a wireless access network is connected.

With reference to the first possible implementation manner, in a second possible implementation manner, the estimating the service according to a bit error rate requirement of the service and load conditions and interference conditions of the multiple radio access networks Obtaining a transmission rate when accessing the multiple radio access networks, respectively, comprising: subtracting a capacity of the radio access network for each of the plurality of radio access networks The current load of the radio access network is obtained, and the remaining capacity of the radio access network is obtained; if the error rate requirement of the service is met, according to the remaining capacity of the radio access network and the radio connection The interference condition of the incoming network, and the available transmission rate when the service is accessed through the wireless access network is estimated.

With reference to the first aspect, or the first or the second possible implementation manner, in a third possible implementation manner, the determining, according to the available transmission rate, from the multiple radio access networks Selecting a radio access network by the service, comprising: comparing an available transmission rate that the plurality of radio access networks can provide for the service; selecting, according to the comparison result, the service from the plurality of radio access networks Provides the wireless access network with the highest transmission rate.

In conjunction with the first aspect or any of the possible implementations of the first to third possible implementations, in a fourth possible implementation, the available transmission rate is the maximum available transmission rate.

With reference to the fourth possible implementation manner, in a fifth possible implementation manner, the error rate requirement includes that an output signal to interference and noise ratio of the receiver is greater than a minimum signal to interference and noise ratio required by the service, where the load is The conditions include the number of services accessing the wireless access network prior to the service.

With reference to the fourth or fifth possible implementation manner, in a sixth possible implementation, the multiple radio access networks include a wideband code division multiple access WCDMA radio access network, and the service passes the WCDMA. The maximum achievable transmission rate when accessing the wireless access network is obtained according to the following formula:

Where ^ ^MAX is the maximum achievable transmission rate, and W _c is the system bandwidth, N. For noise power, N. =«. w _c , «. For noise power spectral density, (Χ, Ζ)) is the neighboring cell interference factor, X is used The distance between the user equipment of the service and the control base station of the current cell is a linear distance between the neighboring cell of the cell where the user equipment is located and the current cell, and N-1 is accessed before the service. The number of services of the WCDMA radio access network is the number of parallel substreams of the i-th service accessing the WCDMA radio access network before the service, i=l, 2, 3, N - l, a minimum signal to interference and noise ratio required for the i-th service, a minimum signal to interference and noise ratio required for the service, an activation factor of the i-th service, and an activation factor of the service , for the spread spectrum gain of the service, (^. is the spread gain of the i-th service, and the maximum received power of the receiver of the service.

With reference to the fourth possible implementation manner, in a seventh possible implementation, the error rate requirement includes a bit error rate (BER) of the service is less than an upper limit of a bit error rate of the service requirement, where the load is The conditions include the number of services accessing the wireless access network prior to the service. It should be understood that the load conditions can also be represented by the number of services and the bandwidth occupied by each service.

With reference to the fourth or seventh possible implementation manner, in an eighth possible implementation manner, the multiple radio access networks include an orthogonal frequency division multiple access (OFDMA) mode radio access network, where the service The maximum achievable transmission rate when accessing through the OFDMA radio access network is obtained according to the following formula:

ν ], (N = , ...NJ,

Where ^ ^MAX is the maximum achievable transmission rate, W. For the bandwidth of each subcarrier of the LTE radio access network, A is the total number of subcarriers of the LTE radio access network line, and is the i-th service occupation of accessing the OFDMA radio access network before the service Number of subcarriers, y(X, = P _N - a(X, DP _N = ^^ , is channel gain, _β (Χ, Ζ)) is neighbor cell interference

^G N

a factor, where X is the distance between the service and the center of the control base station of the current cell, and is a linear distance between the neighboring cell and the current cell, where the N-1 is the access to the service before the service The number of services of the OFDMA radio access network, σ ² is the thermal noise power, _3⁄4 is a parameter for indicating the bit error rate of the service, indicates the activation factor of the service, m is the number of types of services, The maximum transmit power of the transmitter of the service.

With reference to the first aspect, or any one of the first to the eighth possible implementation manners, in the ninth possible implementation manner, the error rate requirement of the acquiring service and the multiple The load condition of the radio access network includes: acquiring, when the bandwidth of the multiple radio access networks is greater than a preset threshold, a bit error rate requirement of the service and a negative of the multiple radio access networks Condition.

With reference to the first aspect or any one of the first to the ninth possible implementation manners, in the tenth possible implementation manner, the error rate requirement of the acquiring service and the multiple The load condition of the radio access network includes: acquiring, when the service is a non-real-time service, a bit error rate requirement of the service and a load condition of the multiple radio access networks.

With reference to the first aspect, or any one of the first to the tenth possible implementation manners, in an eleventh possible implementation manner, the method is performed by a radio resource management device, where the obtaining The error rate requirement of the service and the load condition of the multiple radio access networks, including: the radio resource management device receiving the bit error rate requirement sent by the user equipment and the multiple radio access networks The load condition sent by the base station.

With reference to the eleventh possible implementation manner, in a twelfth possible implementation manner, the method of the second aspect further includes: after accessing the service to the selected radio access network, the radio resource management The device allocates a transmission rate for the service.

With reference to the first aspect or any one of the first to the tenth possible implementation manners, in a possible implementation manner of the thirteenth, the method of the second aspect is performed by the user equipment, where the obtaining The error rate requirement of the service and the load condition of the multiple radio access networks, including: the user equipment acquiring a bit error rate requirement of the service, and receiving a base station in the multiple radio access networks The load condition of the second aspect, the method of the second aspect, further comprising: the user equipment accessing the service to the selected radio access network.

With reference to the first aspect or any one of the first to the tenth possible implementation manners, in a possible implementation manner of the fourteenth, the method is performed by the wireless access network And performing, by the base station in a radio access network, the acquiring a bit error rate requirement of the service and a load condition of the multiple radio access networks, where: the acquiring, by the base station, an interference condition of a first radio access network And a load condition and a load condition of the other radio access networks of the plurality of radio access networks except the first radio access network, and receiving a bit error rate requirement sent by the user equipment.

The second aspect provides an apparatus for selecting a radio access network, including: an acquiring module, configured to acquire a bit error rate requirement of a service and a load condition of multiple radio access networks; and an estimating module, configured to be used according to the service a bit error rate requirement and a load condition of the plurality of radio access networks, estimating an available transmission rate when the service is respectively accessed by the plurality of radio access networks; and a selecting module, configured to: according to the Obtaining a transmission rate for selecting the service from the plurality of wireless access networks A wireless access network to access the selected wireless access network.

With reference to the second aspect, in a first possible implementation, the estimating module estimates that the service is respectively adopted according to a bit error rate requirement of the service and a load condition and an interference condition of the multiple radio access networks. The available transmission rate when the plurality of wireless access networks are connected.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, the estimating module is configured to perform the wireless connection for each of the multiple radio access networks The capacity of the incoming network is subtracted from the current load of the wireless access network, and the remaining capacity of the wireless access network is obtained, and if the error rate requirement of the service is met, according to the wireless access network The remaining capacity and the interference condition of the radio access network are used to estimate an available transmission rate when the service is accessed through the radio access network.

With reference to the second aspect or any one of the possible implementation manners of the first to the second possible implementation manners of the second aspect, in a third possible implementation manner, the selecting module compares the multiple wireless connections The available transmission rate that the inbound network can provide for the service, and according to the comparison result, selects a radio access network that can provide the service with the highest available transmission rate from the plurality of radio access networks.

With reference to the second aspect or any one of the first to third possible implementation manners of the second aspect, in a fourth possible implementation manner, the available transmission rate is the maximum available transmission. rate.

With reference to the fourth possible implementation manner of the second aspect, in a fifth possible implementation manner, the error rate requirement includes that an output signal to interference and noise ratio of the receiver is greater than a minimum signal to interference and noise ratio required by the service. The load condition includes a number of services accessing the wireless access network before the service.

With reference to the fourth or fifth possible implementation of the second aspect, in a sixth possible implementation, the multiple radio access networks include a wideband code division multiple access WCDMA radio access network, and the service is adopted. The maximum achievable transmission rate when the WCDMA radio access network is accessed is obtained according to the following formula:

Where ^ ^MAX is the maximum achievable transmission rate, which is the system bandwidth, N. For noise power, N. =«. w _c , «. For noise power spectral density, (Χ, Ζ)) is the neighboring cell interference factor, X is used The distance between the user equipment of the service and the control base station of the current cell is a linear distance between the neighboring cell of the cell where the user equipment is located and the current cell, and N-1 is accessed before the service. The number of services of the WCDMA radio access network is the number of parallel substreams accessing the i-th service of the WCDMA radio access network before the service, i=l, 2, 3, Nl a minimum signal to interference and noise ratio required for the i-th service, R _w is a minimum signal to interference and noise ratio required by the service, and an activation factor of the i th service is an activation factor of the service , for the spread spectrum gain of the service, (^. is the spread gain of the i-th service, ^ is the maximum received power of the receiver of the service.

With reference to the fourth possible implementation of the second aspect, in a seventh possible implementation, the error rate requirement includes: a bit error rate of the service is less than an upper limit of a bit error rate of the service requirement, The load condition includes the number of services that access the radio access network before the service, and the fourth or seventh possible implementation of the second aspect. In an eighth possible implementation manner, the multiple The radio access network includes an orthogonal frequency division multiple access (OFDMA) radio access network, and the maximum achievable transmission rate when the service is accessed through the OFDMA radio access network is obtained according to the following formula:

N-l pMAX

ν =(AX A)W ₀ log ₂ [l + a _N ^N ' ¹ⁿ _n _ _x ], (N = ,...NJ,

'=i [ ₇ ( ,Ζ)) + _σ ² ]·(Λ-χΑ)

=1

Where ^ ^MAX is the maximum achievable transmission rate, W. For the bandwidth of each subcarrier of the LTE radio access network, A is the total number of subcarriers of the LTE radio access network line, and is the i-th service occupation of accessing the OFDMA radio access network before the service The number of subcarriers, y(X, = P _N -a(X, DP _N =^^ , is the channel gain, _β (Χ Ζ)) is the neighbor cell interference factor, and X is the user equipment using the service. The distance from the center of the control base station of the current cell, is a linear distance between the neighboring cell and the current cell, and the N-1 is a service that accesses the OFDMA radio access network before the service. The number, σ ² is the thermal noise power, is a parameter for indicating the bit error rate of the service, represents an activation factor of the service, m is the number of types of services, and is the maximum transmission of the transmitter of the service. power.

With reference to the second aspect or any one of the first to the eighth possible implementation manners of the second aspect, in the ninth possible implementation manner, the acquiring module is in the multiple wireless connections When the bandwidth of the inbound network is greater than a preset threshold, the error rate requirement of the service and the load condition of the multiple radio access networks are obtained. With reference to the second aspect, or any one of the first to the ninth possible implementation manners of the second aspect, in the tenth possible implementation manner, the acquiring module is not real-time in the service In the case of a service, a bit error rate requirement of the service and a load condition of the plurality of radio access networks are obtained.

With reference to the second aspect, or any one of the first to the tenth possible implementation manners of the second aspect, in an eleventh possible implementation manner, the device is a radio resource management device, where The radio resource management device receives the bit error rate requirement sent by the user equipment and a load condition sent by a base station in the multiple radio access networks.

With the eleventh possible implementation of the second aspect, in a twelfth possible implementation, the radio resource management device further includes: an allocating module, after selecting a radio access network for the service , allocating a transmission rate for the service.

With reference to the second aspect or any one of the first to the tenth possible implementation manners of the second aspect, in a thirteenth possible implementation manner, the device is a user equipment, and the acquiring The module obtains its own error rate requirement, and receives the load condition sent by the base station in the multiple radio access networks, and the acquiring module is further configured to access the service to the selected radio access network.

With reference to the second aspect or any one of the first to the tenth possible implementation manners of the second aspect, in a fourteenth possible implementation manner, the device is the radio access network The base station in the first radio access network, the acquiring module acquires an interference condition and a load condition of the first radio access network, and the plurality of radio access networks except the first radio access network The load conditions of other wireless access networks, and receiving the bit error rate requirements sent by the user equipment.

According to the embodiment of the present invention, when the radio access network is selected for the service of the user equipment, the network access load may be used as a decision criterion to select the radio access network, so that the error rate after the service accesses the network is ensured. The selected radio access network not only meets the requirements of network load balancing but also meets the error rate requirement of the service, so that a suitable radio access network can be selected for the user equipment.

DRAWINGS

1 is a schematic flow chart of a method of selecting a radio access network in accordance with one embodiment of the present invention. 2 is a schematic diagram of a communication system in accordance with an embodiment of the present invention.

3 is a schematic diagram of a user equipment selecting a radio access network in accordance with an embodiment of the present invention. 4 is a cell distribution diagram in accordance with an embodiment of the present invention.

Figure 5 is a block diagram showing the structure of an apparatus for selecting a radio access network according to an embodiment of the present invention.

Figure 6 is a block diagram showing the structure of an apparatus for selecting a radio access network according to another embodiment of the present invention. Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without making creative labor are within the scope of the present invention.

It should be understood that the technical solution of the present invention can be applied to various communication systems, such as: GSM (Global System of Mobile communication) system, CDMA (Code Division Multiple Access) system, WCDMA ( , Wideband Code Division Multiple Access, GPRS (General Packet Radio Service), LTE (Long Term Evolution) system, LTE-A (Advanced long term evolution) The system, the UMTS (Universal Mobile Telecommunication System), and the like are not limited in the embodiment of the present invention. For convenience of description, the embodiment of the present invention will be described by taking an LTE and a WCDMA network as an example. Different network elements can be included in the system. For example, the network elements of the radio access network in the LTE and the LTE-A include an eNB (eNodeB, an evolved base station), and the network elements of the radio access network in the WCDMA include an RNC (Radio Network Controller) and a NodeB, similar to Other wireless networks, such as WiMax (Worldwide Interoperability for Microwave Access), may also use a scheme similar to the embodiment of the present invention, and the related modules in the system may be different. It is not limited, but for convenience of description, the base station in the following embodiments will be described by taking an eNodeB and a NodeB as an example.

It should also be understood that, in the embodiment of the present invention, the user equipment (UE, User Equipment) includes However, it is not limited to a mobile station (MS, Mobile Station), a mobile terminal (Mobile Terminal), a mobile telephone (Mobile Telephone), a handset, and a portable equipment. The user equipment can be accessed via a radio access network (RAN). , Radio Access Network ) communicates with one or more core networks, for example, the user equipment can be a mobile phone (or "cellular" phone), a computer with wireless communication function, etc., and the user device can also be portable, pocket-sized , handheld, computer built-in or in-vehicle mobile devices.

1 is a schematic flow diagram of a method of selecting a wireless access network, in accordance with one embodiment of the present invention. The method of FIG. 1 may be performed by a device for selecting a radio access network, for example, by a radio resource management device or a radio resource management entity, but embodiments of the present invention are not limited thereto, for example, FIG. 1 may also It is executed by a base station or user equipment. The following describes an embodiment of the present invention by taking a radio resource management device as an example. The method of Figure 1 can include the following steps.

110. Obtain a bit error rate requirement of the service and a load condition of multiple radio access networks.

For example, the bit error rate requirement of the service can be represented by the bit error rate of the service, or the bit error rate requirement can also be represented by the bit error rate of the service.

For example, the load conditions of the radio access network may depend on parameters such as the number of services accessing the radio access network and/or the bandwidth occupied by each service. The embodiment of the present invention is not limited thereto, and for example, the load condition may also consider factors such as interference. The load conditions can be measured by the base station (e.g., e-NodeB and NodeB).

120. Estimate an available transmission rate when the service is accessed through multiple radio access networks according to a service error rate requirement and load conditions of multiple radio access networks.

Specifically, each radio access network can provide a limited transmission rate for the service to be accessed due to the limitation of the load conditions of each radio access network and the error rate requirement of the service to be accessed. The transmission rate or the available transmission rate can be obtained.

In other words, the RRC device can derive the achievable transmission rate of the service in each radio access network according to the error rate requirement of the service and the relationship between the load condition of the radio access network and the transmission rate. For example, the available transmission rate of the service in the WCDMA radio access network can be derived according to the transmission model of the WCDMA system (for example, the signal to interference and noise ratio formula), or according to the transmission model of the LTE system (for example, the Shannon formula) Deriving the available transmission rate of the service in the OFDMA radio access network. It should be understood that the load of the radio access network is heavier. For example, the more the number of services that have access to the radio access network, the higher the error rate requirement of the service to be accessed, and the service to be accessed can be The transmission rate obtained by the wireless access network is also lower. 130. Select a radio access network for services from multiple radio access networks according to an available transmission rate, so as to access services to the selected radio access network.

For example, in a scenario where two or more radio access networks cover the same area, when the user equipment needs to access a radio access network in order to use a certain service, the bit error rate request may be sent to the radio resource manager. The radio resource manager may also acquire load conditions of the radio access networks, and for each radio access network, estimate the radio based on load conditions of the radio access network, if the bit error rate requirement of the service is met. The transmission rate that the access network can provide for the service. The radio resource manager can compare the transmission rates that the radio access networks can provide for the service, and select a radio access network according to the comparison result. For example, the radio access network that can provide the highest transmission rate can be selected as the final service. Access to the wireless access network. The radio resource manager may inform the user equipment using the service of the information of the selected radio access network to access the service to the radio access network. It should be understood that the embodiment of the present invention does not limit this. For example, a radio access network capable of providing a transmission rate with a large transmission rate (for example, greater than a preset threshold) may be selected as a radio access network that the service can finally access. .

According to the embodiment of the present invention, when the radio access network is selected for the service, the radio access network may be selected according to the network load as a decision criterion under the condition of ensuring the error rate after the service accesses the network, so that the selected wireless The access network not only meets the requirements of network load balancing, but also meets the error rate requirement of the service, so that a suitable wireless access network can be selected for the service.

It should be understood that the foregoing radio access network may be an OFDMA radio access network or a WCDMA radio access network, and embodiments of the present invention are not limited thereto, and may be, for example, a GSM radio access network. The user equipment may be a multimode terminal supporting multiple wireless access modes.

In 120, the radio resource management device may estimate that the service is accessed by the multiple radio access networks according to a bit error rate requirement of the service and load conditions and interference conditions of the multiple radio access networks. The available transmission rate.

In other words, when estimating the available transmission rate, interference conditions can also be considered, for example, considering the influence of interference between the cell to which the service is to be accessed and the neighboring cell on the available transmission rate. In addition, the interference condition may include noise power brought by the neighboring cell. It should be understood that the greater the interference in the small interval, the smaller the transmission rate that the service can obtain from the wireless access network. In the case of considering interference conditions, a more accurate available transmission rate can be estimated for each radio access network, thereby enabling selection of a more suitable radio access network. For example, the service can be derived from each wireless connection according to the error rate requirement of the service, the load condition of the network, and the relationship between the interference condition and the transmission rate. The available transmission rate into the network. The above interference conditions may be actually measured or estimated according to a channel model. In the embodiment of the present invention, when the radio access network is selected, the corresponding interference condition may be considered according to a certain policy, which is not limited by the embodiment of the present invention.

In 120, the radio resource management device may subtract the current load of the radio access network from the capacity of the radio access network for each radio access network of the plurality of radio access networks to obtain a radio access network. The remaining capacity, and in the case of satisfying the error rate requirement of the service, the available transmission rate when the service is accessed through the radio access network is estimated according to the remaining capacity of the radio access network and the interference condition of the radio access network.

For example, the capacity of the wireless access network can be represented by the number of services that the wireless access network can support. The current load of the wireless access network can be represented by the number of services that have access to the wireless access network, and the remaining capacity is wireless. The number of services that the access network can also accommodate.

In 130, the radio resource management device can compare the available transmission rates that the plurality of radio access networks can provide for the service, and according to the comparison result, select the maximum available transmission rate that can be provided for the service from the plurality of radio access networks. Wireless access network.

Since the load of different radio access networks is different, the available transmission rates that different radio access networks can provide for services are also different. The RRC device can select a wireless access network that can transmit the highest service rate as the wireless access network that the service can finally access, thereby providing an optimal user experience for the user.

According to an embodiment of the invention, the transmission rate is obtained as the maximum achievable transmission rate.

The above achievable transmission for each radio access network may be the maximum achievable transmission rate that the radio access network can provide. In other words, the RRC device can compare the maximum achievable transmission rate that multiple radio access networks can provide for the service, and select the radio access network based on the result of the comparison.

According to an embodiment of the present invention, in a heterogeneous network scenario, when a radio access network is selected for a service, a radio access network selection decision may be performed based on the following principles: In a case where a certain bit error rate requirement is met, the wireless connection is performed. The transmission rate that the incoming network can provide for the service, that is, the available transmission rate of the service in the wireless access network. Since multiple services usually share the resources of the radio access network, the available transmission rate of the service in the radio access network can well characterize the load of the radio access network. In addition, the error rate of the service can also reflect the interference of the service in the wireless access network. The transmission rate and bit error rate obtained by the service also reflect whether the QoS (Quality of Service) level is met. Therefore, according to a certain bit error rate, the wireless access network can The determination of the transmission rate (ie, the available transmission rate of the service) for the selection of the radio access network can better achieve the purpose of network load balancing and user experience.

According to an embodiment of the invention, the bit error rate requirement comprises that the output signal to interference and noise ratio of the receiver is greater than the minimum signal to interference and noise ratio required by the service, the load condition including the number of services accessing the radio access network before the service.

According to an embodiment of the invention, the plurality of radio access networks comprise a wideband code division multiple access WCDMA radio access network, and the maximum achievable transmission rate when the service is accessed through the WCDMA radio access network is obtained according to the following formula:

Where ^ ^MAX is the maximum available transmission rate, ^ is the system bandwidth, w. For noise power,

N ₀ = n ₀ W _c , «. For the noise power spectral density, (Χ, Ζ)) is the neighbor cell interference factor, X is the distance from the control base station of the cell to be accessed, and is the cell to be accessed by the user equipment using the service and the neighboring cell. The linear distance between them, N-1 is the number of services accessing the WCDMA radio access network before the service, and is the number of parallel substreams of the i-th service accessing the WCDMA radio access network before the service, i=l, 2, 3, ..., Nl is the minimum signal to interference and noise ratio required for the i-th service, and R _w is the minimum signal to interference and noise ratio required by the service, which is the activation factor of the i-th service. The activation factor for the service, the spread gain of the service, is the spread gain of the i-th service, and P ^{x is} the maximum received power of the receiver of the service. For example, when the user equipment receives the downlink signal, the receiver is the receiver of the service, and when the base station receives the uplink signal, the receiver is the receiver of the base station.

According to an embodiment of the present invention, the bit error rate requirement includes that the bit error rate of the service is smaller than the upper bit error rate required by the service, and the load condition includes the number of services accessing the radio access network before the service.

According to an embodiment of the present invention, multiple radio access networks include orthogonal frequency division multiple access

In the OFDMA radio access network, the maximum achievable transmission rate when the service is accessed through the OFDMA radio access network is obtained according to the following formula:

Where ^ ^MAX is the maximum available transmission rate, W. For each child of the LTE wireless access network The bandwidth of the carrier, A is the total number of subcarriers of the LTE radio access network line, and A is the number of subcarriers occupied by the i th service of the OFDMA radio access network before the service, _r (X, D) = P _N - a(X, D) , P _N = ^^ , for channel gain, _β (Χ, Ζ)) is the neighbor cell interference factor,

^G N

X is the distance between the user equipment using the service and the center of the control base station of the cell to be accessed, and is the linear distance between the cell to be accessed by the user equipment and the neighboring cell, and N-1 is before the service. the number of the OFDMA wireless network access _services, σ ² is the thermal noise power, _¾ for a parameter representing the bit error rate of traffic representing traffic activating factor, m is the number of types of ^traffic, / Γ χ for the business The maximum transmit power of the transmitter. For example, when the user equipment sends a signal, the transmitter is a transmitter of the user equipment, and when the base station transmits a signal, the transmitter is a transmitter of the base station.

In 110, the radio resource manager may obtain a bit error rate requirement of the service and a load condition of the plurality of radio access networks if the bandwidth of the plurality of radio access networks is greater than a preset threshold.

In other words, the radio resource manager can perform the method of Figure 1 if the bandwidth of the plurality of radio access networks is greater than a predetermined threshold.

In 110, the radio resource manager can obtain the bit error rate requirement of the service and the load condition of the plurality of radio access networks if the service is a non-real time service.

In other words, the radio resource manager can perform the method of Fig. 1 if the service is a non-real time service.

According to an embodiment of the present invention, the method of FIG. 1 is performed by a radio resource management device, wherein in 110, the radio resource management device can receive a bit error rate requirement sent by the user equipment and a load sent by the base station in the plurality of radio access networks. condition.

Optionally, as another embodiment, the method of FIG. 1 further includes: after accessing the selected radio access network, the radio resource management device may allocate an actual transmission rate for the service according to the obtainable transmission rate.

In other words, the available transmission rate can be used only for the selection of the radio access network, and the actual transmission rate of the service can be allocated by the radio resource management device according to a preset policy. Of course, the available transmission rate can also be directly used as the actual transmission rate of the service.

Alternatively, as another embodiment, the method is performed by a user equipment, where in 110, the user equipment can acquire a bit error rate requirement of the service, and receive a load condition sent by the base station in the multiple radio access networks, where The method of 1 further includes: the user equipment accessing the service to the selected radio access network.

Alternatively, as another embodiment, the method consists of a first radio access network in a radio access network The base station in the network performs, in 110, the base station can acquire the load condition of the first radio access network and the load conditions of the radio access networks of the plurality of radio access networks except the first radio access network, and Receive the error rate requirement sent by the user equipment.

It should also be understood that, in the foregoing embodiment, when the method of the embodiment of the present invention is performed by a certain radio resource management device, the radio resource manager may acquire a load condition of the radio access network from a base station of the radio access network, and The bit error rate requirement of the service can be obtained from the user equipment. When the method of FIG. 1 is performed by a base station of a radio access network, the base station can receive a bit error rate request sent by the user equipment, acquire load conditions of other radio access networks, and select the radio access network. Sent to the user device. When the method of FIG. 1 is performed by a user equipment, the user equipment may separately acquire load conditions of each radio access network from base stations of respective radio access networks. Embodiments in accordance with the present invention are not limited to the manner of obtaining load conditions and bit error rate requirements described above, for example, load conditions and bit error rate requirements may be managed by a centralized device, for example, managed by a certain core network device, and Load conditions and bit error rate requirements are provided by the core network device to the user equipment, base station or radio resource manager.

It should also be understood that the radio resource management device of the embodiment of the present invention may also be a functional entity distributed over multiple devices, for example, when the user equipment initiates a call, the user equipment has not accessed any network. At this time, the radio access network may be selected for the service by a call admission control management function entity, which may be distributed (eg, may be logic or code) at the user terminal and the base station (eg, e-NodeB and NodeB) )in. When the user equipment requests the access service, the functional entity may control the user equipment to report the QoS requirements of the service to be accessed to the base station (for example, the e-NodeB and the NodeB) through the signaling channel, where the QoS includes a bit error rate requirement. For another example, when the service has access to the radio access network, when the radio access network needs to be re-selected for the service due to the mobility, the mobility management entity may be between different base stations (for example, e-NodeB and NodeB). Share QoS information of the managed services.

The following example shows how to determine the available transmission rate when a service accesses through a wireless access network. The following takes the WCDMA radio access network and the OFDMA radio access network as an example for description.

2 is a schematic diagram of a communication system in accordance with an embodiment of the present invention. As shown in FIG. 3, the signal from the source is encoded by the source and then arrives at the transmitter. The transmitter performs channel coding, modulation, and spreading processing on the signal, and transmits the signal to the receiver of the communication peer through the wireless channel. After receiving the signal from the wireless channel, the receiver performs despreading, demodulation, and channel decoding processing, and performs signal decoding on the signal to obtain a final signal. The transmitter may be a transmitter of the service, and the receiver may be a base station. Preferably, the embodiment of the present invention is not limited thereto. For example, the transmitter may be a transmitter of a base station, and the receiver may be a receiver of a service. As shown in Fig. 2, the signal to interference and noise ratio at the input of the receiver is expressed as Si/Ni, the signal to interference and noise ratio at the output of the receiver is expressed as So/No, and the error rate at the output of the receiver is expressed as BER.

3 is a diagram of selecting a radio access network for traffic of a user equipment, in accordance with an embodiment of the present invention.

First, a detailed description of how to determine the available transmission rate when a service is accessed through a WCDMA radio access network is described.

It is assumed that the WCDMA radio access network and the OFDMA radio access network are repeatedly covered in the same area. There are multiple services in the two networks, and each service has different transmission rate and bit error rate characteristics. In this case, when a new service faces the choice of a WCDMA radio access network and an OFDMA radio access network, the user needs an optimal user experience. As a network, load balancing is required to achieve maximum network capacity. The maximum transmission rate required by a certain bit error rate that the service can obtain also reflects the load of the network. For many services, such as downloading services, media broadcasting services, etc., it is to obtain the maximum transmission rate under a certain bit error rate requirement.

The embodiment of the present invention can be derived according to the transmission principle of the WCDMA system, and obtain an expression of the maximum value of the available transmission rate when the service accesses through the WCDMA radio access network.

For example, before a new service (e.g., the Nth service) arrives at the WCDMA radio access network, N-1 services have access to the network through the WCDMA radio access network. In this embodiment, it is assumed that the bandwidth of the WCDMA system is W _c and a multi-code transmission mode is employed. In a WCDMA system, the data bit stream generated by the i-th service (i=l, 2...N) is converted into (.. parallel sub-streams by serial-to-parallel conversion. The basic rate B of each sub-flow is the same. Substream

(^. Different spreading codewords are used for spreading, and after spreading (^. sub-data streams are then subjected to parallel and serial conversion, and restored to a data stream transmission.

The power before and after the de-spreading of the Nth service remains unchanged, which is PC _N P _N h _N , where the power of the signal on each spreading code channel is represented, and ^ represents the activation factor of the i-th service, which is used to indicate that the call is active. The ratio of the time (or non-silent) state to the total time.

The following takes the signal to interference and noise ratio in one code channel as an example for description. The power of the single code channel of the Nth service is that the power spectral density before despreading and demodulation can be expressed as the power spectral density when the service received signal is despread and demodulated, which is expressed as, where is the transmission rate of the service. In terms of noise, the external noise spectral density is . In addition, the noise also includes interference of other N-1 services, taking into account mutual interference between cells, using (Χ, Ζ) as an interference factor of cells to be accessed by other cells to affect new services, and the sum of the above interferences Can be expressed as +

After despreading and demodulating, except for the Nth service being demodulated back to the baseband, the other N-1 services are not demodulated as interference, and the power before demodulation is maintained.

[1 + α(Χ, ))]∑^3⁄4 -C _N P _N h _N

Density, therefore, the sum of the powers of the above noises is ^.

^W c

Through the above analysis, the signal to interference and noise ratio of the Nth service at the receiver of the service can be expressed as the following formula:

[X+aiX ^Cfi^ -C _N P _N h _N [X+aiX ^Cfi^ -C _N P _N h _N +n ₀ W _c [l+aiX^^C^h, -C _N P _N h _N +N ₀

+".

" ( 1 ) where ^N is the noise power, w. = «.w _c , ". For noise power spectral density.

In order to meet the QoS requirements of the service data transmission, for example, the bit error rate requirement, the following conditions may be met: the output signal to interference and noise ratio of the receiver's demodulator is greater than the minimum signal to interference and noise ratio R _{N of} the Nth service requirement, namely:

SINR _N = >R _N (2)

[1 + α(Χ, ))]∑^.3⁄4— C _N P _N h _N +N ₀ According to the formula (2), the following formula (3) can be obtained:

N

(ia(X,D)--^-C _N h _N )P _N >-^·{[1 + α( , ))]·∑ ΡΛ +N ₀ } ( 3 )

G _N -r _N sets the lower limit of the power in equation (3) to /, that is:

C _i P _i h _i +N ₀ } (4)

According to formula (4), / can be expressed as follows:

C„R

[l + a(X,D)]- c

p* = ^C N ^R NK + G _{N (} y _{c ph} ! W ₀

^N C^ -C^-^aiX^y ''' H ₊ a(X, _D)]

C _N R _N h _N + G _N

(5) Then transform the formula (5) into the same form as the base function part of the series:

W _c - C _N h _N P _N * = [1 + a(X, D)] - ^C ^ ^R ^ ^W c . [Tc^h, + ^ ^ ^ ] (6)

C _N R _N h _N + G _N i ^{1 1 1} [l + a(X, D)] Equation (6) applies to the Nth business, for any i-th service (i=l, 2, .. .N) It is also applicable to change the subscript N in the formula to i, and then add i from 1 to N on both sides of the equation to obtain:

(7)

Equation (7) can be further reduced to: CR^Wc _N

±C _A P; - ^ ⁷ ^' . (8)

Ψ _€ -[1 + α(Χ, )].^— Bring the formula (8) back to the formula (6), you can get:

(9) After formulating (9), you can get:

Among them, cy^p is the minimum power that the third service satisfies its QoS, and this power increases as the number of existing services in the network increases. The more the number of existing services, the larger the 分, the smaller the denominator, the larger the C _N h _N P ₁ ; that is, the power should increase as the load in the network increases, but the power cannot be increased indefinitely. Large, therefore, the upper limit depends on the receiver's maximum received power, set to

Ρ , that is, ςΑΛ* ≤ Γ ^χ , brought into the formula ( 10 ) to get the formula ( 11 ):

^C

^U According to formula (11):

(12) Further obtained according to formula (12):

Solve the inequality of equation (13):

MAX

C _i R _i h _i + G _i P, N

(14) Among them, set V. For the transmission rate of each sub-stream, the maximum achievable transmission rate V ^AX that the WCDMA network can provide to the Nth service in the solvable domain of the power control is:

(15) For the cell, the interference factor _Ω (Χ, )) of other cells affecting the cell is:

2(Ρ + Χ +2(Ρ-Χ +2Ρ- ^η

a(X,D) = ( 16)

X where, assuming that the location of the user using the Nth service is known to be in the network, X is the Nth The distance between the user equipment of the service and the base station of the cell, is the linear distance between the neighboring cell and the local cell, (Χ, Ζ)) is the neighboring cell interference factor, where η is the path attenuation factor.

Next, how to determine the available transmission rate when a service accesses through an OFDMA radio access network is described in detail.

In an OFDMA radio access network, the transmission bandwidth of the system is divided into a series of orthogonal subcarrier sets that do not overlap each other. The bandwidth resource allocation is directly dependent on the number of subcarriers. In this embodiment, it is assumed that the bandwidth of each subcarrier is W. The total number of subcarriers is A. Before a new service (eg, the Nth service) arrives at the OFDMA radio access network, a total of N-1 services access the OFDMA radio access network. First consider the speed year V _JN that can be achieved on a single carrier of the Nth service. According to the Shannon formula, the formula (17) can be obtained:

V _1N = W ₀ log ₂ {l + a _N · ^ ^GjnPjN . } ,

^]N . ^{2 N} [γ{Χ, Ό) + σ ² \ (17) where Χ, Ζ)) is the measurable noise power brought by the neighboring cell, which together with the thermal noise power σ ² reflects the Nth service The interference condition in the network, that is, the above interference condition can be expressed by the noise power and thermal noise power brought by the neighboring cells. Is the bit error rate requirement of the third service, a _N -1.5/lo _g (5*B. is the bit error rate of the service. (^ is the channel gain of the Nth service on subcarrier j. Is the ^th The power of the traffic on subcarrier j.

If all the subcarriers used in the Nth service are taken into consideration, since the number of subcarriers of the Nth service is the number of subcarriers _A that have been occupied by the W-1 carrier, the total number of remaining subcarriers is

W-1

Λν =Α-3⁄4 , then the rate that the wth service can get ^ can be expressed by equation (18): W ] _ns ,

In the expression, ^ denotes the total average power allocated to the Nth service, (^ denotes the average channel gain of the Nth service; and the activation factor representing the Nth service.

In order to make the available transmission rate when the radio access network is selected for the user equipment as large as possible, the spare subcarriers in the radio access network are all allocated to the Nth service, since occupying all the remaining resources of the network, N services usually get a higher rate than other N-1 services. Moreover, when the number of vacant subcarriers of the network is determined and the bit error rate is constant, the achievable transmission rate of the Wth service can be limited to one variable: power. According to formula (18), the relationship between the rate and the power of the service can be easily obtained, that is, the transmission power allocated to the service is increased. At the same time, the rate ^ will also increase, and the two exhibit a monotonically increasing function relationship through zero. Considering that the received power cannot be higher than the maximum power that the service can receive ^ that is, <^.^ ≤ ^, thereby determining the upper limit of the rate of the Nth service ^ is expressed as:

For a cell, the relationship between the interference power X,^ of the neighboring cell and the power of the transmitted signal can be determined by = "(X, = · ^2(£> + ^{Χ Γ +2(£>} " ^{Γ + 2D} ", Because of

X

(19) Take ^, substitute, then (^) = ^ · ^{2( ) + Χ)} — " ⁺² ( ^D _ ^X) — " ⁺² " , by

^G N ^G NX

This can calculate the value of Χ, Ζ)), where _Ω (Χ, )) is the interference factor of the neighboring cell, m is the number of types of services, and N _m is the number of the mth type of service.

Can also be seen from equation (19), the greater the number of services, the greater the load on the network, the maximum transmission rate obtained ^Χ will be reduced, in the same manner, a bit error rate of Ν higher traffic requirements, will be reduced .

How to obtain or derive the neighbor cell interference factor _Ω (Χ, )) is described in detail below. 4 is a cell distribution diagram in accordance with an embodiment of the present invention.

Assuming that the transmit power of each base station is constant and the path attenuation is checked, under this condition, the ratio of the signal power to the adjacent cell interference power can be expressed as:

∑ ( D "

S_ _ X

=> a ( X , D ) (20)

X

1 ∑ ( D i )

i = 1 where X is the distance between the location where the user equipment receives the signal from the cell center base station and the cell center. . The number of neighboring cells is the distance between the central base station of each neighboring cell and the user equipment, and n is the path attenuation factor.

Referring to FIG. 4, for example, it is assumed that the neighbor cell interference received by the cell mainly comes from the adjacent six neighbor cells, that is, . = 6 , A can be approximated as DX DX DD D+X D+X (set D as the distance between the center of the cell and the center of the neighboring cell), substituting into equation (20) to get: i _v n 2(D + Xr ⁿ + 2 (DX +2D- ⁿ It should be understood that, in the embodiment of the present invention, the base station controls six cells as an example to describe how to obtain the neighbor cell interference factor. In fact, the base station may also control other numbers of cells, which are implemented by those skilled in the art according to the present invention. The content disclosed in the example knows how to obtain the neighbor cell interference factor when the base station controls a plurality of cells.

When the user equipment is in a heterogeneous wireless network, the user equipment usually chooses to access the network with the network resources dominant by judging the network conditions. Embodiments of the present invention are network selection schemes based on comparing available transmission rates. Before selecting a wireless access network for services entering the heterogeneous network coverage, the service can be calculated according to the above scheme according to formulas (15) and (19), respectively, in the WCDMA radio access network and the OFDMA radio access network. Obtain the transmission rate

M _A , then, compares the & and V^MA pairs, and determines the wireless access network that the service can access according to the comparison result. This network selection scheme can accurately reflect the advantages and disadvantages of network resources, is convenient to calculate, and is relatively straightforward, and can provide fast and accurate network selection for services.

As described above, based on the relationship between the transmission rate, the load condition, and the bit error rate requirement, the transmission rate that the radio access network can provide can be derived, for example, formula (15) and formula (19), thereby establishing A model used to obtain the available transmission rate. In order to verify the beneficial effects that the embodiments of the present invention can produce, the following simulation tests were conducted. Take the wireless heterogeneous network where WCDMA and OFDMA coexist as an example.

Assume that in the initial state, there is no service access, and then new services access the network one by one. Each service adopts the above-mentioned comparison access scheme that can obtain the transmission rate to access the network, and each service is used as the available transmission rate of the service after the load is affected. Assume that the business used by the business includes real-time business and non-real-time business. The two types of services of the service are different in terms of the activation factor, the signal to interference and noise ratio, the bit error rate, and the number of occupied subcarriers (the number of substreams). Therefore, when the service uses these two types of services as a load, the service is available. The effect of the maximum transmission rate is also different. For real-time services, for example, voice services, because the required transmission rate is fixed, in general, exceeding the required transmission rate has little meaning for improving the service quality of the service. Therefore, for such services, the transmission rate can be relatively obtained. The access scheme can be used to select a network with small load and low interference. After the real-time service enters the radio access network, the media access control (MAC) layer of the accessed radio access network controls the allocation of the transmission rate. For non-real-time services, for example, downloading services, browsing web pages, etc., the higher the transmission rate, the higher the user experience. Therefore, selecting the network with the highest transmission rate can not only balance the load of the entire communication network, but also obtain a larger load. The transmission rate, so that the business gets the best experience. It should be understood that when performing simulation, the maximum transmission rate that can be obtained can be The upper limit of the available transmission rate of the service, and how much transmission rate is actually allocated for the service, can be allocated by the MAC layer of the radio access network after accessing the radio access network. Embodiments of the present invention are concerned with the maximum achievable transmission rate that a service can obtain from a wireless access network.

When the foregoing service is used, the existing resources of the two radio access networks may be separately evaluated according to the available transmission rate of the two radio accesses, so that the service can access the appropriate radio access network. . Different services consume different levels of radio access network resources. The radio access network can allocate network resources according to service requirements. The degree of consumption of network resources by the load directly affects the available transmission rate of the services arriving in the radio access network. How many.

According to the above scheme, the network is accessed, and the comparison and competition of the available transmission rates provided by the two radio access networks continue as the arrival of new users continues. The two radio access networks compete with each other and alternately become the winners of the game. To achieve a balance between network resources.

According to the simulation result, the following conclusion can be drawn: The access scheme based on comparing the obtainable transmission rate is compared with the access scheme based on comparing SINR, the maximum obtainable transmission rate of the former is greater than or equal to the maximum obtainable transmission rate of the latter, This embodies the advantages of the technical solution of the embodiment of the present invention in resource balanced allocation and user experience.

For example, Table 1 is the network selection situation of users in the number of arrivals of each user in the network selection scheme based on the network selection scheme with the highest transmission rate when the interference factor is certain (for example, the interference factor is 0.1).

Table 1

It can be seen from Table 1 that selecting OFDMA and selecting WCDMA is a mutual game between radio access networks. As a result, the resources of the two networks alternately decrease as the user arrives. For example, if a network with a relatively dominant resource is selected by the user, the resource will be reduced until it is lower than the other network. Thus, the user starts to select another network and consumes its resources, thereby achieving network resource balance.

In addition, simulations were performed for different interference factors and different bandwidths (for example, 5M/10M/15M/20M), and the following results were obtained:

(1) The available transmission rate value decreases as the number of arriving services increases. The available transmission rate of the WCDMA radio access network drops rapidly in the early stage of service arrival, when it falls to the OFDMA radio access network. When the transmission rates are similar, the network selection is started according to the available transmission rate comparison algorithm. After that, the two networks compete with each other, and the available transmission rates of the two networks also decrease at a relatively slow speed.

(2) The greater the bandwidth, the sooner the competition between the two networks will occur. Since the initial achievable transmission rate of the OFDMA radio access network increases significantly with the increase of the system bandwidth, for example, when the system bandwidth is 20M, the initial achievable transmission rate of the two networks is close to 4, and the two networks are in the user. The access phase begins to compete for resources, and the available transmission rate decreases slowly as the competition progresses. This shows that the algorithm has higher resource utilization efficiency in the case of larger bandwidth, and avoids the problem of drastic drop in transmission rate due to the large difference in the initial available transmission rates of the two networks.

Figure 5 is a block diagram showing the structure of an apparatus 500 for selecting a radio access network in accordance with one embodiment of the present invention. The apparatus 500 includes an acquisition module 510, an estimation module 520, and a selection module 530.

The obtaining module 510 is configured to obtain a bit error rate requirement of the service and load conditions of the plurality of radio access networks. The estimation module 520 is configured to estimate an available transmission rate when the service is accessed through multiple radio access networks according to the error rate requirement of the service and the load conditions of the multiple radio access networks. The selection module 530 is configured to select a wireless access network for the service from the plurality of wireless access networks in accordance with the available transmission rate to access the selected wireless access network.

According to an embodiment of the present invention, the estimation module 520 estimates the available transmission rate when the service is accessed through multiple radio access networks according to the error rate requirement of the service and the load conditions and interference conditions of the plurality of radio access networks.

According to an embodiment of the present invention, the estimation module 520 subtracts the current load of the radio access network from the capacity of the radio access network for each radio access network of the plurality of radio access networks, and obtains the remaining of the radio access network. Capacity, and in the case of satisfying the error rate requirement of the service, according to the remaining capacity of the radio access network and the interference condition of the radio access network, the available transmission rate when the service accesses through the radio access network is estimated. According to an embodiment of the present invention, the selection module 530 compares the available transmission rates that the plurality of radio access networks can provide for the service, and selects the maximum available transmission rate that can be provided for the service from the plurality of radio access networks according to the comparison result. Wireless access network.

Where ^ ^MAX is the maximum available transmission rate, which is the system bandwidth, N. For noise power,

N ₀ = n ₀ W _c , «. For the noise power spectral density, (Χ, Ζ)) is the neighbor cell interference factor, X is the distance between the user equipment using the service and the control base station of the current cell, and is the neighboring cell and the current cell of the cell where the user equipment is located. The straight-line distance between them, N -1 is the number of services accessing the WCDMA radio access network before the service, and the number of parallel sub-streams of the i-th service accessing the WCDMA radio access network before the service, 1 =1, 2, 3, ..., N -1 , is the minimum signal to interference and noise ratio required for the i-th service, the minimum signal to interference and noise ratio required for the service, and the activation factor of the i-th service, h _N is the activation factor of the service, which is the spread gain of the service, and is the spread gain of the i-th service, which is the maximum received power of the receiver of the service.

According to an embodiment of the invention, the bit error rate requirement includes a bit error rate of the service that is less than a bit error rate upper limit of the service requirement used by the user equipment, and the load condition includes the number of services accessing the radio access network before the service.

According to an embodiment of the present invention, the multiple radio access networks include an orthogonal frequency division multiple access (OFDMA) radio access network, and the maximum achievable transmission speed when the service is accessed through the OFDMA radio access network

Where ^ ^MAX is the maximum available transmission rate, W. For the bandwidth of each subcarrier of the LTE radio access network, A is the total number of subcarriers of the LTE radio access network line, and A is the number of subcarriers occupied by the i th service of the OFDMA radio access network before the service, _r (X, D) = P _N - a(X, D) , _β (Χ, Ζ)) is the neighboring cell interference factor, X is the distance between the service and the center of the control base station of the current cell, and is the neighboring cell The linear distance from the current cell, N - 1 is the number of services accessing the OFDMA radio access network before the service, _σ ² is the thermal noise power, and _3⁄4 is the parameter for indicating the bit error rate of the service, indicating the service The activation factor, m is the number of types of services, and the maximum transmit power of the transmitter for the service.

According to an embodiment of the present invention, the obtaining module 510 acquires a bit error rate requirement of the service and a load condition of the plurality of radio access networks if the bandwidth of the plurality of radio access networks is greater than a preset threshold.

According to an embodiment of the present invention, the obtaining module 510 obtains a bit error rate requirement of the service and a load condition of the plurality of radio access networks when the service is a non-real time service.

According to an embodiment of the present invention, the apparatus of FIG. 5 is a radio resource management apparatus, and the radio resource management apparatus receives a bit error rate requirement transmitted by the user equipment and a load condition sent by the base station in the plurality of radio access networks.

Optionally, as another embodiment, the radio resource management device further includes: an allocating module 540, configured to allocate a transmission rate for the service after the radio access network is to be selected for the service.

According to an embodiment of the present invention, the apparatus 500 of FIG. 5 is a user equipment, and the obtaining module 510 acquires its own error rate requirement, and receives a load condition sent by a base station in multiple radio access networks, where the user equipment further includes The access module 550 is configured to access the selected radio access network.

According to an embodiment of the present invention, the apparatus 500 of FIG. 5 is a base station in a first radio access network of a plurality of radio access networks, and the acquiring module 510 acquires interference conditions and load conditions of the first radio access network, and multiple A load condition of a radio access network other than the first radio access network in the radio access network, and receiving a bit error rate requirement sent by the user equipment.

Figure 6 is a block diagram showing the structure of an apparatus 600 for selecting a radio access network in accordance with another embodiment of the present invention. Apparatus 600 includes a processor 610, a memory 620, and a communication bus 630.

The processor 610 is configured to invoke the code stored in the memory 620 through the communication bus 630 to obtain a bit error rate requirement of the service and load conditions of the plurality of radio access networks, according to the error rate requirement of the service and the multiple radio access networks. Load condition, estimate the available transmission rate when the service accesses through multiple radio access networks respectively, and select one radio access network for the service from multiple radio access networks according to the available transmission rate, so as to Access the selected wireless access network. According to an embodiment of the present invention, the processor 610 estimates the available transmission rate when the service is accessed through multiple radio access networks according to the error rate requirement of the service and the load conditions and interference conditions of the multiple radio access networks.

According to an embodiment of the present invention, the processor 610 subtracts the current load of the radio access network from the capacity of the radio access network for each radio access network of the plurality of radio access networks, and obtains the remaining of the radio access network. Capacity, and in the case of satisfying the error rate requirement of the service, according to the remaining capacity of the radio access network and the interference condition of the radio access network, the available transmission rate when the service accesses through the radio access network is estimated.

According to an embodiment of the present invention, the processor 610 compares the available transmission rates that the plurality of radio access networks can provide for the service, and selects the maximum available transmission rate that can be provided for the service from the plurality of radio access networks according to the comparison result. Wireless access network.

N ₀ = n ₀ W _c , «. For the noise power spectral density, (Χ, Ζ)) is the neighbor cell interference factor, X is the distance between the user equipment using the service and the control base station of the current cell, and is between the neighboring cell of the cell where the user equipment is located and the current cell. The linear distance, N -1 is the number of services accessing the WCDMA radio access network before the service, ς. is the number of parallel sub-streams of the i-th service accessing the WCDMA radio access network before the service, i =l, 2, 3, ..., N - 1 , the minimum signal to interference and noise ratio required for the i-th service, the minimum signal to interference and noise ratio required for the service, the activation factor of the i-th service, h _N is the activation factor of the service, which is the spread gain of the service, and is the spread gain of the i-th service, and P ^x is the maximum received power of the receiver of the service.

According to an embodiment of the present invention, the bit error rate requirement includes a bit error rate of the service is less than that required by the service. The upper limit of the bit error rate, the load condition includes the number of services accessing the radio access network before the service.

N-l pMAX

ν =(AX )W ₀ log ₂ [l + a _N ^N · ^ηΝ _N _, UN = ,...NJ,

'=i [ ₇ ( ,Ζ)) + _σ ² ]·(Λ-χΑ)

=1

Where ^ ^MAX is the maximum available transmission rate, W. For the bandwidth of each subcarrier of the LTE radio access network, A is the total number of subcarriers of the LTE radio access network line, and A is the number of subcarriers occupied by the i th service of the OFDMA radio access network before the service, r(X,D) = P _N -a(X,D) , P _N = S^ , is the channel gain, (Χ,Ζ)) is the neighbor cell interference factor,

^G N

X is the distance between the service and the center of the control base station of the current cell, and is the linear distance between the neighboring cell and the current cell, and N-1 is the number of services accessing the OFDMA wireless access network before the service, σ ² For thermal noise power, _3⁄4 is a parameter for indicating the bit error rate of the service, indicating the activation factor of the service, m is the number of types of services, and is the maximum transmission power of the transmitter of the service.

According to an embodiment of the present invention, the processor 610 acquires a bit error rate requirement of the service and a load condition of the plurality of radio access networks if the bandwidth of the plurality of radio access networks is greater than a preset threshold.

According to an embodiment of the present invention, the processor 610 acquires a bit error rate requirement of the service and a load condition of the plurality of radio access networks when the service is a non-real time service.

According to an embodiment of the present invention, the apparatus of FIG. 6 is a radio resource management device, and the processor 610 is further configured to acquire a bit error rate requirement sent by the user equipment and a load condition sent by the base station in the multiple radio access networks.

Optionally, as another embodiment, the processor 610 is further configured to allocate a transmission rate for the service after accessing the selected wireless access network.

According to an embodiment of the present invention, the apparatus 600 of FIG. 6 is a user equipment, the processor 610 acquires its own error rate requirement, and the processor 610 is further configured to acquire a load condition sent by a base station in multiple radio access networks, where the processing is performed. The 610 is also used to access the selected radio access network.

According to an embodiment of the present invention, the apparatus 600 of FIG. 6 is a base station in a first radio access network of the plurality of radio access networks, and the processor 610 is further configured to acquire an interference condition and a load condition of the first radio access network. And loading conditions of the radio access networks of the plurality of radio access networks except the first radio access network, and receiving a bit error rate requirement sent by the user equipment. The embodiment of the present invention derives the transmission rate of the user under the above parameters according to parameters such as the number of services, interference conditions, and the like in different networks, and according to the user error rate requirement (QoS requirement). The appropriate network is selected by comparing the transmission rate of a certain error rate obtained by the services of the wireless access network to be accessed in different networks.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in a combination of electronic hardware or computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

It will be apparent to those skilled in the art that, for the convenience of the description and the cleaning process, the specific operation of the system, the device and the unit described above may be referred to the corresponding processes in the foregoing method embodiments, and details are not described herein again.

In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be electrical, mechanical or otherwise.

The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential to the prior art or part of the technical solution, may be embodied in the form of a software product stored in a storage medium, including a number of instructions to make a computer device (which can be a personal computer, a server, Or a network device or the like) performing all or part of the steps of the method of the various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like, which can store program codes. .

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

Rights request

1. A method of selecting a wireless access network, characterized by including:

Obtain the bit error rate requirements of the service and the load conditions of multiple wireless access networks;

According to the bit error rate requirements of the service and the load conditions of the multiple wireless access networks, estimate the obtainable transmission rate when the service is accessed through the multiple wireless access networks respectively;

Select a wireless access network for the service from the plurality of wireless access networks according to the available transmission rate, so that the service is accessed to the selected wireless access network.

2. The method according to claim 1, characterized in that, according to the bit error rate requirements of the service and the load conditions of the multiple wireless access networks, it is estimated that the service passes through the multiple wireless access networks. Achievable transmission rates when connected to the access network, including:

According to the bit error rate requirements of the service and the load conditions and interference conditions of the multiple wireless access networks, the obtainable transmission rate when the service is accessed through the multiple wireless access networks is estimated.

3. The method according to claim 2, characterized in that, according to the bit error rate requirements of the service and the load conditions and interference conditions of the multiple wireless access networks, it is estimated that the service passes the Achievable transmission rates when multiple wireless access networks are connected, including:

For each wireless access network in the plurality of wireless access networks, subtract the current load of the wireless access network from the capacity of the wireless access network to obtain the remaining load of the wireless access network. ,

When the bit error rate requirement of the service is met, the error rate when the service is accessed through the wireless access network is estimated based on the remaining capacity of the wireless access network and the interference condition of the wireless access network. Available transfer rates.

4. The method according to any one of claims 1 to 3, characterized in that: selecting a wireless access network for the service from the plurality of wireless access networks based on the obtainable transmission rate. into the network, including:

Compare the available transmission rates that the multiple wireless access networks can provide for the service; According to the comparison results, select the wireless access network that can provide the highest available transmission rate for the service from the multiple wireless access networks. Enter the network.

5. The method according to any one of claims 1 to 4, characterized in that the obtainable transmission rate is the maximum obtainable transmission rate.

6. The method according to any one of claims 5, characterized in that, the bit error rate The requirements include that the output signal-to-interference-to-noise ratio of the receiver is greater than the minimum signal-to-interference-to-noise ratio required by the service, and the load condition includes the number of services that access the wireless access network before the service.

7. The method according to claim 5 or 6, characterized in that: the plurality of wireless access networks include a wideband code division multiple access WCDMA wireless access network, and the service is accessed through the WCDMA wireless access network The maximum achievable transmission rate is obtained according to the following formula:

Where, ^ ^MAX is the maximum obtainable transmission rate, and is the system bandwidth, N. is the noise power, N. =«. w _c , «. is the noise power spectrum density, (Χ, Z)) is the interference factor of neighboring cells, X is the distance between the user equipment using the service and the control base station of the current cell, ) is the neighboring cell of the cell where the user equipment is located The straight-line distance between the current cells, N - 1 is the number of services that access the WCDMA wireless access network before the service, ς is the number of services that access the WCDMA wireless access network before the service The number of parallel sub-streams of the i-th service, i=l, 2, 3, N -1, is the minimum signal-to-interference-to-noise ratio required by the i-th service, and is the minimum signal-to-interference and noise ratio required by the i-th service. Noise ratio, is the activation factor of the i-th service, is the activation factor of the service, is the spreading gain of the service, (^. is the spreading gain of the i-th service, ^ is the spreading gain of the i-th service, The maximum received power of the receiver for the above service.

8. The method according to claim 5, characterized in that, the bit error rate requirement includes that the bit error rate of the service is less than the upper limit of the bit error rate required by the service, and the load condition includes before the service The number of services accessing the wireless access network.

9. The method according to claim 5 or 8, characterized in that, the plurality of wireless access networks include Orthogonal Frequency Division Multiple Access OFDMA wireless access networks, and the service passes through the OFDMA wireless access network. The maximum obtainable transmission rate during access is obtained according to the following formula: ,

Where, ^ ^MAX is the maximum obtainable transmission rate, W. is the bandwidth of each subcarrier of the LTE wireless access network, A is the total number of subcarriers of the LTE wireless access network line, and is occupied by the i-th business accessing the OFDMA wireless access network before the service The number of subcarriers, y(X, P _N - a(X, DP _N is the channel gain, (Χ, Ζ)) is the interference of neighboring cells Factor, The number of services in the OFDMA wireless access network, _σ ² is the thermal noise power, _¾ is a parameter used to represent the bit error rate of the service, represents the activation factor of the service, m is the number of types of services, is the The maximum transmit power of the transmitter for the above service.

10. The method according to any one of claims 1 to 9, characterized in that the bit error rate requirements for obtaining services and the load conditions of the multiple wireless access networks include:

When the bandwidths of the multiple wireless access networks are greater than the preset threshold, the bit error rate requirements of the service and the load conditions of the multiple wireless access networks are obtained.

11. The method according to any one of claims 1 to 10, characterized in that the bit error rate requirements for obtaining the service and the load conditions of the multiple wireless access networks include:

When the service is a non-real-time service, the bit error rate requirement of the service and the load conditions of the multiple wireless access networks are obtained.

12. The method according to any one of claims 1 to 11, characterized in that, the method is executed by a wireless resource management device, and the obtaining the bit error rate requirements of the service and the plurality of wireless access Load conditions entering the network, including:

The wireless resource management device receives the bit error rate requirement sent by the user equipment and the load conditions sent by the base stations in the multiple wireless access networks.

13. The method according to claim 12, further comprising:

After the service is accessed to the selected wireless access network, the wireless resource management device allocates a transmission rate to the service.

14. The method according to any one of claims 1 to 11, characterized in that: the method is executed by user equipment, and the obtaining the bit error rate requirements of the service and the plurality of wireless access networks load conditions, including:

The user equipment obtains the bit error rate requirement of the service and receives the load conditions sent by the base stations in the multiple wireless access networks,

The method also includes:

The user equipment accesses the service to the selected wireless access network.

15. The method according to any one of claims 1 to 11, characterized in that: the method is executed by a base station in a first wireless access network in the wireless access network, and the obtaining the The bit error rate requirements of the service and the load conditions of the multiple wireless access networks include:

The base station obtains interference conditions and load conditions of the first wireless access network and the plurality of load conditions of other wireless access networks in the wireless access network except the first wireless access network, and receive the bit error rate requirements sent by the user equipment.

16. A device for selecting a wireless access network, characterized by including:

Acquisition module, used to obtain the bit error rate requirements of the service and the load conditions of multiple wireless access networks;

An estimation module, configured to estimate the obtainable transmission rate when the service is accessed through the multiple wireless access networks according to the bit error rate requirements of the service and the load conditions of the multiple wireless access networks;

A selection module, configured to select a wireless access network for the service from the plurality of wireless access networks according to the available transmission rate, so as to access the service to the selected wireless access network.

17. The device according to claim 16, characterized in that, the estimation module estimates the throughput of the service according to the bit error rate requirements of the service and the load conditions and interference conditions of the multiple wireless access networks. The available transmission rate when the multiple wireless access networks are accessed.

18. The apparatus according to claim 17, characterized in that, for each of the plurality of wireless access networks, the estimating module subtracts the capacity of the wireless access network from the capacity of the wireless access network. The current load of the wireless access network is used to obtain the remaining capacity of the wireless access network, and when the bit error rate requirements of the service are met, based on the remaining capacity of the wireless access network and the wireless access The interference conditions of the network are used to estimate the obtainable transmission rate when the service is accessed through the wireless access network.

19. The device according to any one of claims 16 to 18, characterized in that the selection module compares the available transmission rates that the multiple wireless access networks can provide for the service, and based on the comparison As a result, the radio access network that can provide the maximum obtainable transmission rate for the service is selected from the plurality of radio access networks.

20. The device according to any one of claims 16 to 19, characterized in that the obtainable transmission rate is the maximum obtainable transmission rate.

21. The device according to any one of claims 20, wherein the bit error rate requirement includes that the output signal-to-interference-to-noise ratio of the receiver is greater than the minimum signal-to-interference-to-noise ratio required by the service, and The load condition includes the number of services accessing the radio access network before the service.

22. The device according to claim 20 or 21, characterized in that, the plurality of wireless access networks include a wideband code division multiple access WCDMA wireless access network, and the service passes through the The maximum obtainable transmission rate when accessing the WCDMA wireless access network is obtained according to the following formula:

Where, ^ ^MAX is the maximum obtainable transmission rate, and is the system bandwidth, N. is the noise power, N. =«. w _c , «. is the noise power spectrum density, (Χ, Z)) is the interference factor of neighboring cells, X is the distance between the user equipment using the service and the control base station of the current cell, ) is the neighboring cell of the cell where the user equipment is located The straight-line distance between the current cells, N - 1 is the number of services that access the WCDMA wireless access network before the service, ς is the number of services that access the WCDMA wireless access network before the service The number of parallel sub-streams of the i-th service, i=l, 2, 3, N -1, is the minimum signal-to-interference-to-noise ratio required by the i-th service, and is the minimum signal-to-interference and noise ratio required by the i-th service. Noise ratio, is the activation factor of the i-th service, is the activation factor of the service, is the spreading gain of the service, (^. is the spreading gain of the i-th service, h is the spreading gain of the i-th service, The maximum received power of the service receiver.

23. The device according to claim 20, wherein the bit error rate requirement includes that the bit error rate of the service is less than the upper limit of the bit error rate required by the service, and the load condition includes before the service The number of services accessing the wireless access network.

24. The device according to claim 20 or 23, characterized in that, the plurality of wireless access networks include Orthogonal Frequency Division Multiple Access OFDMA wireless access networks, and the service passes through the OFDMA wireless access network The maximum obtainable transmission rate during access is obtained according to the following formula: ν = (A - ], (N = U, ...N _m ),

Where, ^ ^MAX is the maximum obtainable transmission rate, W. is the bandwidth of each subcarrier of the LTE wireless access network, A is the total number of subcarriers of the LTE wireless access network line, and is occupied by the i-th business accessing the OFDMA wireless access network before the service The number of subcarriers, γ(Χ,σ) = Ρ _Ν · α(Χ,σ) , Ρ _Ν = ^^ , is the channel gain, _β (Χ,Ζ)) is the interference factor of neighboring cells, and The distance between the user equipment of the service and the center of the control base station of the current cell, ) is the straight-line distance between the neighboring cell and the current cell, and the N - 1 is the OFDMA accessed before the service The number of services in the wireless access network, _σ ² is the thermal noise power, _¾ is a parameter used to represent the bit error rate of the service, represents the activation factor of the service, m is the number of types of services, is the The maximum transmit power of the service transmitter.

25. The device according to any one of claims 16 to 24, characterized in that, when the bandwidth of the plurality of wireless access networks is greater than a preset threshold, the acquisition module acquires the service Bit error rate requirements and loading conditions of the multiple radio access networks.

26. The device according to any one of claims 16 to 25, characterized in that, when the service is a non-real-time service, the acquisition module obtains the bit error rate requirement of the service and the Load conditions for multiple radio access networks.

27. The device according to any one of claims 16 to 26, characterized in that: the device is a wireless resource management device, and the wireless resource management device receives the bit error rate requirement sent by the user equipment and load conditions sent by base stations in the plurality of wireless access networks.

28. The device according to claim 27, characterized in that the wireless resource management device further includes:

An allocation module, configured to allocate a transmission rate to the service after selecting a wireless access network for the service.

29. The device according to any one of claims 16 to 26, characterized in that the device is user equipment, the acquisition module acquires its own bit error rate requirements, and receives the multiple wireless access The load condition sent by the base station in the network, and the acquisition module is also used to access the service to the selected wireless access network.

30. The device according to any one of claims 16 to 26, characterized in that: the device is a base station in the first wireless access network in the wireless access network, and the acquisition module acquires the third Interference conditions and load conditions of a wireless access network and load conditions of other wireless access networks in the plurality of wireless access networks except the first wireless access network, and receive the information sent by the user equipment. Bit error rate requirements.