CN108770025B - A Handover Method for Heterogeneous Wireless Networks Based on RAN Slicing - Google Patents

Abstract

heterogeneous wireless network switching method based on RAN slices, which solves the problem of neglecting user customized service and customized service interruption in the switching process of the prior art, comprises the steps of (1) selecting an optimal target wireless network, (2) judging whether the RAN slices required by a user exist in the network, if so, executing the step (6), otherwise, executing the step (3), (3) sending a request for constructing the RAN slices, (4) constructing the RAN slices required by the user, (5) sending a switching request, (6) releasing the connection between the wireless network and the user, (7) establishing the connection between the optimal target wireless network and the user, and (8) scheduling the RAN slices required by the user.

Description

A Handover Method for Heterogeneous Wireless Networks Based on RAN Slicing

technical field

The invention belongs to the field of communication technologies, and further relates to a heterogeneous wireless network handover method based on RAN (Radio Access Network) slices in the field of wireless communication technologies. The present invention can be used in wireless communication systems to ensure optimal target wireless network scheduling of wireless access network RAN slices, and users can enjoy customized services and heterogeneous network handover of customized service continuity.

Background technique

Heterogeneous wireless network refers to the intelligent combination of overlapping wireless access systems of different types, and a variety of different types of networks jointly provide users with wireless access anytime, anywhere. Heterogeneous network handover refers to the transformation of network state and structure to another network state and structure. It is a network state handover process, which can better meet the needs of providing services to users.

The State Grid Corporation of China disclosed in its patent document "A Method and System for Judgment Control of Vertical Handover between Heterogeneous Wireless Networks" (application date: August 9, 2013, application number: 2013103474024, application publication number: CN103533577A) A vertical handover decision control method between heterogeneous wireless networks. The specific steps of the method are: Step 1: When the connection between the user and the current network does not meet the user's service requirements, the user sends a handover request to the base stations of all heterogeneous networks in the scan list that meet the user's service requirements. In the second step, all base stations receiving the handover request transmit the handover request to the vertical handover controller through their respective wireless sensors. In the third step, the wireless sensor collects and stores the channel resource allocation and usage information of each base station in real time, and the vertical handover controller calculates the channel resource allocation and usage of each candidate base station according to the historical channel resource allocation and usage of each candidate base station for which the mobile client sends a handover request. Blocking probability, the mobile user terminal is seamlessly connected to the base station with the smallest blocking probability. There are three shortcomings in this method: First, the vertical handover decision process decides to trigger network selection at an appropriate time. User application requirements for predetermined information, user terminal performance, etc., all depend on complex computational complexity and parameter signaling overhead. The complexity of the vertical handover decision system is increased, and the channel resource overhead is large. Second, when the mobile client performs handover connection, it requires seamless handover connection between heterogeneous networks, which has extremely high requirements on system performance and is not easy to achieve, resulting in discontinuous services and inability to provide customization for users. service and reduce the quality of service for users.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a method for handover of heterogeneous wireless networks based on RAN slicing of the radio access network, aiming at the above-mentioned defects in the prior art, and the method for handover of heterogeneous wireless networks refines handover between traditional heterogeneous networks. It is the handover from the RAN slice in the wireless network before the handover to the RAN slice in the optimal target wireless network, so as to ensure that users enjoy customized services and service continuity, and improve user service quality and network reliability respectively.

The idea to achieve the above purpose is that the central controller constructs RAN slices of the radio access network according to user requirements, and the optimal target wireless network schedules the RAN slices of the radio access network required by users. During the scheduling process, when the RAN slice of the radio access network before the handover cannot meet the user's needs, the central controller constructs a RAN slice of the radio access network that can meet the user's needs, and then the user switches from the radio network before the handover to the optimal target. Wireless network, the optimal target wireless network schedules the RAN slice of the wireless access network according to the user's needs; when the RAN slice of the wireless access network of the optimal target wireless network can meet the user's needs, the user directly switches from the wireless network before the handover to the RAN slice. Optimal target wireless network. The optimal target wireless network schedules RAN slices of the radio access network according to user requirements.

The technical scheme adopted by the present invention comprises the following steps:

(1) Select the optimal target wireless network:

(1a) Using the periodic information exchange method, the central controller and the local controller exchange information, and use the user requirements after information interaction, the available resources and status information of each network in the heterogeneous wireless network to update the user requirements before the interaction in real time. , the available resources and status information of each network in the heterogeneous wireless network;

(1b) Using the multi-attribute decision-based network selection access algorithm in the central controller, the user requirements after interaction and the available resources and status information of each network in the heterogeneous wireless network are used as the multi-attribute decision-based network selection. The input parameters of the access algorithm select the optimal target wireless network that meets the user's needs in the heterogeneous wireless network;

The central controller determines whether there is a radio access network RAN slice required by the user in the optimal target wireless network, and if so, executes step (6), otherwise, executes step (3);

(3) Send a request to construct a radio access network RAN slice:

The central controller sends the request for constructing the RAN slice of the radio access network required by the user to the local controller of the optimal target radio network;

(4) Constructing the RAN slice of the radio access network required by the user:

(4a) After the local controller of the optimal target radio network receives the request for constructing the RAN slice of the radio access network required by the user, it constructs the radio access network required by the user according to the radio, computing, and storage resource parameters contained in the request. RAN slice;

(4b) The local controller of the optimal target radio network feeds back the information of the RAN slice of the radio access network required by the constructed user to the central controller;

(5) Send a handover request:

After receiving the feedback information of the RAN slice of the radio access network required by the user, the central controller sends the handover request to the wireless network before handover and the optimal target wireless network in the heterogeneous wireless network respectively;

(6) Release the connection between the wireless network and the user:

After receiving the handover request, the wireless network before the handover in the heterogeneous wireless network releases the connection with the user, and feeds back the handover completion information to the central controller.

(7) Establish the connection between the optimal target wireless network and the user:

After receiving the handover request, the optimal target wireless network establishes a connection with the user, and feeds back the handover completion information to the central controller.

(8) Scheduling the radio access network RAN slice required by the user:

(8a) After the central controller receives the feedback information of the wireless network before handover and the feedback information of the optimal target wireless network, the central controller sends the information of scheduling the RAN slice of the wireless access network required by the user to the optimal target wireless network ;

(8b) After receiving the scheduling information, the optimal target wireless network schedules the RAN slice of the wireless access network required by the user to provide services for the user.

Compared with the prior art, the present invention has the following advantages:

First, the present invention adopts the method that the central controller constructs the RAN slice of the radio access network according to the user's requirements, and the optimal target wireless network schedules the RAN slice of the radio access network required by the user, which overcomes the ignoring of the user in the handover process of the prior art. The problem of customized service enables the present invention to greatly ensure the service quality of the user's business during the handover process, and improves the user's customized service experience.

Second, the present invention adopts the method that the central controller constructs the RAN slice of the radio access network according to the user's requirements, and the optimal target wireless network schedules the RAN slice of the radio access network required by the user, which overcomes the customization in the handover process of the prior art. The problem of service interruption enables the present invention to greatly ensure the continuity of the customized service in the handover process and improve the reliability of the network.

Description of drawings:

Fig. 1 is the flow chart of the present invention;

FIG. 2 is a scene diagram of the present invention performing heterogeneous wireless network handover.

Detailed ways:

The present invention will be further described below with reference to the accompanying drawings.

Referring to FIG. 1 , the implementation steps of the present invention will be further described.

Step 1, select the optimal target wireless network.

Using the periodic information exchange method, the central controller exchanges information with the long-term evolution LTE controller and the wireless local area network WLAN controller respectively, and uses the information exchanged user requirements, available resources and status information of each network in the heterogeneous wireless network in real time. Update user requirements before interaction, available resources and status information of each network in heterogeneous wireless networks.

The specific steps of the periodic information interaction method are as follows:

Step 1: After the LTE controller and the wireless local area network WLAN controller send the synchronization sequence number packet to the central controller, the long-term evolution LTE controller and the wireless local area network WLAN controller undergo state transition respectively, and the monitoring state is stored as the sending state. state;

The second step is to compare whether the synchronization sequence number packet of the central controller is consistent with the synchronization signal of the packet header of the received synchronization sequence number packet, if so, execute the fourth step, otherwise, execute the third step;

Step 3: The central controller sends the feedback information of the synchronization sequence number packet it has received to the LTE controller for long-term evolution and the WLAN controller, respectively, and applies to the LTE controller for long-term evolution and the WLAN controller for re-sending the synchronization sequence numbered package;

Step 4: After the central controller simultaneously sends a synchronization sequence number packet and the feedback information of the synchronization sequence number packet received to the LTE controller and the wireless local area network WLAN controller, the central controller undergoes state transition and is monitored by the monitor. The state is stored as receiving state;

Step 5: After both the LTE controller for long-term evolution and the WLAN controller for the wireless local area network receive the synchronization sequence number packet and the feedback information from the central controller simultaneously sent by the central controller, the LTE controller for long-term evolution and the WLAN controller for It receives the feedback information from the central controller and sends it to the central controller;

Step 6, the central controller receives the feedback information from the LTE controller and the WLAN controller, and sends them to the LTE controller and the WLAN controller respectively, and then establishes the central controller and the long-term WLAN controller. The data transmission connection between the evolved LTE controller and the central controller and the wireless local area network WLAN controller realizes the information exchange during data transmission between the two controllers.

Using the multi-attribute decision-based network selection access algorithm in the central controller, the user requirements after interaction and the available resources and status information of each network in the heterogeneous wireless network are used as the multi-attribute decision-based network selection and access algorithm. The optimal target wireless network that meets the user's needs is selected in the heterogeneous wireless network.

The specific steps of the network selection access algorithm based on multi-attribute judgment are as follows:

Step 1, the central controller selects the heterogeneous wireless network state attributes of the received signal strength, available bandwidth, and bit error rate of each wireless network in the heterogeneous wireless network, and uses the AHP to determine the state attributes of each selected wireless network weight value;

Step 2: Calculate the user satisfaction of each wireless network in the heterogeneous wireless network according to the following user satisfaction formula;

Among them, U _n represents the user satisfaction of the nth wireless network in the heterogeneous wireless network, T represents the total number of state attributes of the heterogeneous wireless network, ∑ represents the summation operation, t represents the sequence number of the state attributes of the heterogeneous wireless network, ω _t represents the weight value of the t-th wireless network state attribute in the heterogeneous wireless network, d _nt represents the parameter value of the t-th network state attribute of the n-th wireless network in the heterogeneous wireless network, represents the symbol of any element selected, n represents the serial number of the wireless network in the heterogeneous wireless network, ∈ represents the belonging symbol, and N represents the total number of wireless networks in the heterogeneous wireless network.

The third step is to select a wireless network with the highest user satisfaction among the heterogeneous wireless networks as the optimal target wireless network to meet the user's needs.

Step 2, the central controller judges whether there is a radio access network RAN slice required by the user in the optimal target wireless network, if yes, executes step 6; otherwise, executes step 3.

The radio access network RAN slice required by the user refers to a radio access network RAN slice that can meet the user rate and service quality requirements in terms of radio, computing, and storage resources.

Step 3, sending a request for constructing a RAN slice of the radio access network.

The central controller sends the request for constructing the RAN slice of the radio access network required by the user to the local controller of the optimal target radio network.

Step 4, construct the RAN slice of the radio access network required by the user.

After the local controller of the optimal target wireless network receives the request forwarded by the virtual access point AP to construct the RAN slice of the user-required radio access network, it constructs the user-required radio access network RAN slice according to the wireless, computing, and storage resource parameters contained in the request. Radio access network RAN slice.

The wireless local area network WLAN controller of the optimal target wireless network feeds back to the central controller the information of the RAN slices of the wireless access network required by the constructed user.

Step 5, sending a handover request.

After receiving the feedback information of the RAN slice of the radio access network required by the user, the central controller sends the handover request to the wireless network before handover and the optimal target wireless network in the heterogeneous wireless network respectively.

Step 6, release the connection between the wireless network and the user.

After the wireless network before the handover in the heterogeneous wireless network receives the handover request, it forwards the connection release information to the user through the virtual access point AP, releases the connection between the wireless network before the handover and the user, and feeds back the handover completion information to the central controller .

Step 7: Establish a connection between the optimal target wireless network and the user.

After the optimal target wireless network receives the handover request, it forwards the connection establishment information to the user through the virtual access point AP, establishes the connection between the optimal target wireless network and the user, and feeds back the handover completed information to the central controller.

2, the present invention will further describe the process of sending a handover request, releasing the connection between the wireless network and the user, and establishing the connection between the optimal target wireless network and the user.

After receiving the feedback information of the RAN slice of the radio access network required by the user, the central controller sends the handover request to the wireless network before handover and the optimal target wireless network in the heterogeneous wireless network respectively. After the wireless network before the handover receives the handover request, it releases the connection with the user, and feeds back the handover completion information to the central controller. After receiving the handover request, the optimal target wireless network establishes a connection with the user and sends the handover completion information. Feedback to the central controller.

Heterogeneous wireless network handover scenario diagram includes central controller, long-term evolution LTE controller, wireless local area network WLAN controller, base station, virtual access point AP, user and cloud graph, solid coil under long-term evolution LTE controller, base station under The dashed circle, the dashed circle under the virtual access point AP, the arrow between the user and the user, the thick dashed line through the LTE controller, the base station and the user through the long-term evolution, and the WLAN controller, the virtual access point AP and the user. User's bold solid line, where:

The central controller determines the existence of the RAN slice of the radio access network required by the user, constructs the RAN slice of the radio access network required by the user, and sends the user's release connection request and The user's request for establishing a connection causes the user to switch from the wireless network before the handover to the optimal target wireless network, and the optimal wireless network schedules the constructed RAN slice of the wireless access network required by the user.

The long-term evolution LTE controller controls the base station to forward data to the user, and sends information feedback to the central controller.

The base station is responsible for sending the user demand information of the wireless network before the access handover to the LTE controller for long-term evolution, and sending the feedback information that the LTE controller for long-term evolution needs to release the connection with the user to the user.

The wireless local area network WLAN controller, according to the wireless, computing, and storage resource parameter requirements contained in the user service request, schedules the RAN slices of the wireless access network that can meet the user's needs, and provides customized services for the user.

The virtual access point AP is responsible for sending the information of user requirements for accessing the optimal target wireless network to the wireless local area network WLAN controller, and sending feedback information that the wireless local area network WLAN controller needs to establish a connection with the user to the user.

A user is a user who applies for a service service request to a heterogeneous wireless network.

A cloud-like graphic representing a heterogeneous wireless network.

The real coil under the LTE controller for long-term evolution is the set of the wireless network before handover and the range of the target wireless network.

The dotted circle under the base station is the set of wireless networks before handover.

The dotted circle under the virtual access point AP is the optimal target wireless network.

The arrows between users indicate that the user switches from accessing the wireless network before handover to accessing the optimal target wireless network.

Bold dashed lines through the LTE controller, base station and user indicate that the user forwards data through the base station, and the wireless network before handover accesses the RAN slice of the LTE radio access network.

The bold solid line passing through the wireless local area network WLAN controller, the virtual access point AP, and the user indicates that the user transmits data through the virtual access point AP, and accesses the wireless access network RAN slice of the wireless local area network WLAN in the optimal target wireless network. .

The heterogeneous wireless network based on the RAN slice of the radio access network includes at least one pre-handover wireless network and at least one target wireless network. Among them, the wireless network soft and target wireless network before handover can correspond to networks of various wireless standards. In this example, the most commonly used long-term evolution LTE and wireless local area network WLAN networks are used as the wireless network before handover and the optimal target wireless network respectively. The network, referred to as the long-term evolution LTE network soft base station and the wireless local area network WLAN network soft virtual access point AP, is used to describe the handover process of the user from the long-term evolution LTE network to the wireless local area network WLAN network.

Step 8: Schedule RAN slices of the radio access network required by the user.

After the central controller receives the feedback information of the wireless network before handover and the feedback information of the optimal target wireless network, the central controller sends the information of scheduling the RAN slice of the wireless access network required by the user to the optimal target wireless network.

After receiving the scheduling information, the optimal target wireless network schedules the RAN slice of the wireless access network required by the user, forwards the data to the user through the virtual access point AP, and provides services for the user.

Claims (3)

1, heterogeneous wireless network switching method based on RAN slice, wherein the central controller constructs RAN slice according to user requirement, the optimal target wireless network schedules the RAN slice of the wireless access network required by the user, the method comprises the following steps:

(1) selecting an optimal target wireless network:

(1a) by utilizing a periodic information interaction method, the central controller and each local controller carry out information interaction, and the user requirements before interaction, the available resources and the state information of each network in the heterogeneous wireless network are updated in real time by using the user requirements after the information interaction, the available resources and the state information of each network in the heterogeneous wireless network;

(1b) selecting an optimal target wireless network meeting user requirements from the heterogeneous wireless networks by using a network selection access algorithm based on multi-attribute judgment in the central controller and taking the interacted user requirements and available resources and state information of each network in the heterogeneous wireless networks as input parameters of the network selection access algorithm based on the multi-attribute judgment;

the network selection access algorithm based on the multi-attribute decision comprises the following specific steps:

, selecting the heterogeneous wireless network state attributes of the received signal intensity, the available bandwidth and the error rate of each wireless network in the heterogeneous wireless networks by the central controller, and determining the weight value of each selected wireless network state attribute by using an analytic hierarchy process;

secondly, calculating the satisfaction degree of each wireless network in the heterogeneous wireless networks to the user according to the following user satisfaction degree formula;

wherein, U_nIndicating satisfaction of the nth wireless network among the heterogeneous wireless networks with the user, T indicating the total number of heterogeneous wireless network status attributes,Σ denotes a summation operation, t denotes a sequence number of heterogeneous wireless network status attributes, ω_tWeight value, d, representing the t-th wireless network status attribute in a heterogeneous wireless network_ntA parameter value representing a tth network status attribute of an nth wireless network of the heterogeneous wireless networks,the symbol of any element is selected, N represents the serial number of the wireless network in the heterogeneous wireless network, e represents the symbol, and N represents the total number of the wireless networks in the heterogeneous wireless network;

selecting wireless networks which enable the user satisfaction to be highest in the heterogeneous wireless networks as optimal target wireless networks meeting the user requirements;

(2) the central controller judges whether a Radio Access Network (RAN) slice required by a user exists in the optimal target wireless network, if so, the step (6) is executed, and if not, the step (3) is executed;

(3) sending a request for constructing a Radio Access Network (RAN) slice:

the central controller sends a request for constructing a Radio Access Network (RAN) slice required by a user to a local controller of an optimal target wireless network;

(4) constructing a Radio Access Network (RAN) slice required by a user:

(4a) after receiving a request for constructing a Radio Access Network (RAN) slice required by a user, a local controller of an optimal target wireless network constructs the RAN slice required by the user according to wireless, computing and storage resource parameters contained in the request;

(4b) the local controller of the optimal target wireless network feeds back the information of the constructed radio access network RAN slices required by the user to the central controller;

(5) sending a switching request:

after receiving feedback information of a Radio Access Network (RAN) slice required by a user, the central controller respectively sends a switching request to a wireless network before switching and an optimal target wireless network in heterogeneous wireless networks;

(6) releasing the connection between the wireless network and the user:

after receiving the switching request, the wireless network before switching in the heterogeneous wireless network releases the connection with the user and feeds switching completion information back to the central controller;

(7) establishing the connection between the optimal target wireless network and the user:

after receiving the switching request, the optimal target wireless network establishes connection with a user and feeds switching completion information back to the central controller;

(8) scheduling radio access network RAN slices for user requirements:

(8a) after the central controller receives feedback information of a wireless network before switching and feedback information of an optimal target wireless network, the central controller sends information of a Radio Access Network (RAN) slice required by a scheduling user to the optimal target wireless network;

(8b) and after receiving the scheduling information, the optimal target wireless network schedules the RAN slice required by the user and provides service required by the user.

2. The method for switching heterogeneous wireless network based on RAN slice of wireless access network according to claim 1, wherein the method for periodically interacting information in step (1a) comprises the following steps:

, after the local controller sends the synchronous sequence number packet to the central controller, the local controller is in state transition and stored as a sending state from a monitoring state;

step two, comparing whether the synchronous sequence number packet of the central controller and the received synchronous signal of the packet header of the synchronous sequence number packet are , if so, executing the step four, otherwise, executing the step three;

thirdly, the central controller sends the feedback information of the synchronization sequence number packet received by the central controller to the local controller, and applies for resending the synchronization sequence number packet to the local controller;

fourthly, after the central controller simultaneously sends synchronous sequence number packets and feedback information of the synchronous sequence number packets received by the central controller to the local controller, the central controller is subjected to state transition and is stored in a receiving state from a monitoring state;

fifthly, after the local controller simultaneously receives the synchronous sequence number packet of the central controller and the feedback information sent by the central controller, the local controller sends the feedback information received by the local controller to the central controller;

and sixthly, the central controller sends the feedback information received by the central controller to the local controller, and then establishes data transmission connection between the two controllers, so that information interaction is realized when the two controllers transmit data.

3. The method of claim 1, wherein the RAN slice in step (2) is a RAN slice that satisfies user speed and qos requirements in radio, computing, and storage resources.

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