CN100433888C - A method and system to utilize multi 802.16d base station to cover subscriber group densely - Google Patents

Abstract

The present invention relates to a method and system for densely covering user groups by using multiple 802.16d base stations. The method includes the following steps: Step 1, base station interference isolation under the condition of limited frequency resources, which is used to make full use of resources and ensure bandwidth required by users ; Step 2, the user terminal automatically selects a strong signal base station, which is used to enable the user terminal to automatically access a strong signal base station; Step 3, the unified database management of the user terminal authentication parameters, used for unified management of the user terminal authentication ; When the user terminal is in the blind area of the 802.16d base station, the user terminal switches to the existing mobile network. The invention enables the user terminal to access the 802.16d base station with the strongest signal without manual selection, realizes unified management of user authentication, and can use various integrated services provided by WiMAX.

Description

A method and system for densely covering user groups with multiple 802.16d base stations

technical field

The present invention relates to a communication technology, in particular to a method and system for densely covering user groups with multiple 802.16d base stations.

Background technique

The access network is the foundation of fixed data services, and the intelligentization of access equipment, diversification of access technologies, and broadbandization are the development trends of future networks. According to the development of technology and the situation of the existing network, the access network technology is mainly divided into two major methods: wired access and wireless access: wired access adopts optical fiber access or upgrades the existing copper wire network to As the main technology and means of broadband access. Wireless access mainly includes Local Multipoint Distribution System (LMDS), Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX), etc. Due to the mobility advantages of wireless technology itself, it has a good development Foreground, especially WiMAX technology has higher access bandwidth and larger coverage, and has won the favor of users. WiMAX technology has many advantages such as high bandwidth, wide coverage, and mobile support. It is regarded as the next-generation broadband wireless technology by the industry and has very broad prospects. With the improvement of standards and the maturity of products, WiMAX will become an effective supplement to wired broadband access methods. Since some operators lack resources in wired broadband access, WiMAX technology can become an effective way to develop broadband services. As a fixed wireless last mile access or mobile broadband IP network access, WiMAX network does not pose a substantial threat to the mainstream business of mobile operators, but is a benign supplement to its comprehensive access capabilities and service provision capabilities . The adoption of WiMAX and other wireless last-mile coverage network technologies is bound to greatly increase the user access capabilities and service penetration capabilities of operators, enrich the coverage capabilities of various applications, and penetrate into urban, suburban, and rural areas where copper cables are scarce. The loyalty of network users, thus forming a comprehensive access with multiple business capabilities and multiple access methods.

WiMAX terminals have various forms, including outdoor type, indoor type, card type, built-in notebook computer, handheld, etc. As the first step of WiMAX application, outdoor and indoor terminals that support static access are of great significance. In particular, indoor terminals do not require indoor wiring, and are an important means for realizing wireless digital subscriber lines (DSL). However, the signal of indoor terminals is not as good as that of outdoor terminals. In addition, there are few WiMAX frequency resources and the capacity of a single base station is limited. How to use multiple base stations to provide high-capacity and dense coverage for user groups is a difficult problem.

In the prior art, a user can be covered by multiple base stations, but the user can only manually set the frequency points of each base station, and decide which frequency point to use by manual comparison. To allow users to choose different base stations, they must pass the authentication of these base stations. At present, many user authentication data are configured in different base stations, so it is not flexible enough.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a method and system for densely covering user groups by using multiple 802.16d base stations. The base station with the strongest signal, and unified management of user terminal authentication.

The present invention provides a method for densely covering user groups with multiple 802.16d base stations, comprising the following steps:

Step 1, base station interference isolation under the condition of limited frequency resources, is used to make full use of resources and ensure the bandwidth required by users;

Step 2, the user terminal automatically selects a strong signal base station, so that the user terminal automatically accesses the strong signal base station;

Step 3, the unified database management of the user terminal authentication parameters is used for unified management of the user terminal authentication;

When the user terminal is in the blind area of the 802.16d base station, the user terminal is handed over to the existing mobile network.

The isolation in step 1 includes frequency isolation, distance isolation, polarization isolation, direction isolation and/or building barrier isolation.

The parameters of user terminal authentication are stored in Extensible Markup Language.

The parameters of the user terminal authentication are queried and acquired through the light directory access protocol.

Described step 2 comprises the following steps:

Step 51, the user terminal scans the downlink, and establishes synchronization with the base station;

Step 52, the user terminal extracts transmission parameters from the uplink channel descriptor;

Step 53, the user terminal performs ranging;

Step 54, the user terminal accesses the base station with the strongest signal according to the signal strength indication.

The present invention also discloses a system for densely covering user groups with multiple 802.16d base stations, including:

The isolation module is used for base station interference isolation under the condition of limited frequency resources, so as to make full use of resources and ensure the bandwidth required by users;

The user terminal may automatically select a strong signal base station, so that the user terminal automatically accesses the strong signal base station;

A unified authentication module, used for unified database management of the user terminal authentication parameters;

A switching module, configured to switch the user terminal to an existing mobile network when the user terminal is in a blind area of an 802.16d base station.

The present invention can use multiple base stations to provide dense user capacity and signals, reduce interference between base stations, and allow users to automatically select high-strength signals, and can downgrade to cdma2000 or other mobile networks in special cases, ensuring the continuity of user services sex. The invention enables terminal users to access the 802.16d base station with the strongest signal without manual selection, realizes unified management of user authentication, and can use various comprehensive services provided by WiMAX.

Description of drawings

Fig. 1 is a network structure diagram of an embodiment of the present invention;

FIG. 2 is a schematic diagram of network planning according to an embodiment of the present invention;

Fig. 3 is a schematic flow diagram of a unified authentication database system utilizing an embodiment of the present invention;

Fig. 4 is the structural representation of the handover fusion of 802.16d system and cdma2000 utilizing the embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a user group densely covered by multiple base stations according to an embodiment of the present invention.

Detailed ways

The method and system for using multiple 802.16d base stations to densely cover user groups according to the present invention includes the following steps: Step 1, base station interference isolation under the condition of limited frequency resources, which is used to make full use of resources and ensure the bandwidth required by users ; Step 2, the user terminal automatically selects a strong signal base station, which is used to enable the user terminal to automatically access a strong signal base station; Step 3, the unified database management of the user terminal authentication parameters, used for unified management of the user terminal authentication ; When the user terminal is in the blind area of the 802.16d base station, the user terminal switches to the existing mobile network. The system includes: an isolation module, which is used for base station interference isolation under the condition of limited frequency resources, so as to make full use of resources and ensure the bandwidth required by users; user-side terminal equipment (CPE) (generally refers to user terminals), which can automatically select strong signal base stations , enabling the user terminal to automatically access a strong signal base station; further comprising a user terminal unified authentication module, used for unified database management of the user terminal authentication parameters; a switching module, used when the user terminal is in a blind area of the 802.16d base station , the user terminal switches to the existing mobile network.

The network structure diagram of the embodiment of the present invention is shown in FIG. 1 . The base station 101 is connected to the switch 103 through the service access control point (SACP) 102 , and connected to the IP core network 105 through the switch 103 . A network management system (NMS) server 112 , a call control module (CCM) 106 , a service server 104 , and a user data server 113 are also connected to the IP core network 105 . The computer or telephone 107 can access the base station 101 through the indoor user terminal (SS) 111 embedded in the gateway, and can also be connected to the indoor SS 108 through the gateway 109, thereby accessing the base station 101, and can also be connected to the gateway 109, and then through the indoor SS 108, access the base station 101 through the outdoor antenna 110, or access the base station 101 through the outdoor antenna 110 through the indoor SS 111 with an embedded gateway. The base station 101 may also be directly connected to the IP core network 105 through the service access control point 102 . The network planning under the condition of limited frequency resources includes frequency isolation: the purpose of frequency isolation is achieved by planning different sectors and different remote stations using different frequencies; distance isolation: increasing the distance between small intervals to increase the strength of interference signals attenuation; polarization isolation: increase the isolation between carriers by using different polarization methods of the carrier; direction isolation: distinguish the carrier transmission and reception directions by using different orientations of sector antennas and directional antennas; other On the one hand, it can be further isolated according to the specific terrain and features to reduce interference, and the base station coverage can be controlled by adjusting the base station transmission power, antenna height, and antenna inclination to reduce the overlap and cross-over phenomenon of different base station coverage.

As shown in Figure 2, before network planning, site survey is required in the early stage, which includes the collection of geographical data 201, users and services 202, and polarization type 203, and then proposes and modifies the cell coverage 204, and calculates Traffic capacity and update network size 205, allocate radio frequency (RF) channels and calculate signal strength indication (RSSI), C/I 206, monitor network performance 207, conduct field measurements 208 and network configuration 209 if requirements are met, otherwise start from 204 , to execute repeatedly.

In the present invention, the parameters for user terminal authentication are changed from decentralized storage in the base station to centralized storage in the database management system in the form of Extensible Markup Language (XML), and are queried and acquired through the Lightweight Directory Access Protocol (LDAP) and other methods. As shown in Figure 3, it is a schematic flow diagram of the unified authentication database system utilizing the present invention; the user terminal authentication parameter unified database management system is responsible for controlling the user terminal (SS) authorization process, that is, the terminal first sends authentication information 301 to the base station, including CA certificate ( CA-Certificate), and then send an authentication request 302, which includes SS certificate (SS-Certificate,), security (Security), capability (Capabilities) and security association identifier (SAID), and the base station (BS) authenticates the identity of the SS , BS sends an authentication response (AK) 303 to the authenticated SS, including authentication key (AUTH-Key), key lifetime (Key-Lifetime), key sequence number (Key SequenceNumber), SA descriptor ( SA Descriptor) and public key management (PKM) configuration, the terminal sends a key response 304, including the key sequence number (Key Sequence Number), SAID and HMAC (Hash function based Message Authentication Code, hash-based message authentication code ) summary (HMAC-Digest), the base station sends a key response 305, including TEK (TrafficEncryption Key, traffic encryption key) 0, TEK1, also includes key sequence number (Key SequenceNumber), SAID, new and old TEK parameters and HMAC summary (HMAC-Digest), then terminal and base station encrypt 306 using TEK.

The invention automatically selects a strong signal of a base station through a user terminal. The optimization process can be divided into the following stages: 802.16d terminal scans the downlink and establishes synchronization with BS; 802.16d terminal extracts transmission parameters from the uplink channel descriptor (UCD); 802.16d terminal performs ranging; 802.16d base station negotiates Basic performance of SS; 802.16d base station authenticates SS and performs key exchange; 802.16d terminal registers; 802.16d terminal establishes IP connection with 802.16d base station, transmits operating parameters, and establishes connection. After the 802.16d terminal performs ranging, the 802.16d terminal accesses the base station with the strongest signal according to its signal strength indicator (RSSI).

As shown in Figure 4, 3G core network 406 is connected with Bill server 401, home agent 402, home AAA 403, packet data serving node (PDSN) 407 and Internet 413, and PDSN 407 is connected with local AAA 405, radio access node/packet control entity (RAN/PCF) 404, access service node (ASN) gateway 411 is connected, and existing mobile network comprises base station 409 and RAN/PCF 404 as cdma2000 system 408, and WiMAX system 410 comprises access point 412 and ASN gateway 411, ASN gateway 411 may also be directly connected to the Internet 413. The user terminal 414 can switch from the 802.16d system to the CDMA 2000 system. The present invention further compensates for insufficient signal coverage by switching and merging the 802.16d system and the mobile network system. Therefore, when the user terminal is in the blind area of the 802.16d system, it can switch to the existing mobile network, such as the cdma2000 system. There are two cases of loose coupling and tight coupling. Loose coupling has little changes to the existing network, while tight coupling has major changes to the existing network. In the loosely coupled scenario, WiMAX mobility management is implemented by the WiMAX gateway, which switches to a mobile network such as the cdma2000 system through the instructions of the WiMAX gateway. In the tightly coupled scenario, the packet data service node in the mobile cell also participates in the WiMAX terminal. Mobility management, through the packet service support node of the core network, instructs the terminal to switch to the existing mobile network. The mobile network is not limited to the cdma2000 system, and can also be a WCDMA system, or a TD-SCDMA system, etc.

sub option Tight coupling Loose coupling certified Authentication System Using Cellular Network Provide conversion of authentication information by setting up a gateway Billing Billing System Using Cellular System Unified billing through conversion Mobility Management Entity Dedicated service support node for core network Home Agent (HA) to switch Handover Mechanism of Cellular Network Mobile IP switching System Management Unified management manage separately System Deployment New Development The service supports node updates, and the terminal supports multiple signaling New Gateway, Billing Transition Entity standard Interface of service support node Extensible Authentication Protocol (EAP)

It is very convenient to join and withdraw from the integrated and open telecommunication network service platform of the present invention, and the scope can be expanded infinitely.

The present invention will be further described in detail below in conjunction with FIG. 5 .

For the typical building coverage of operators, the following user bandwidth requirement assumptions are put forward, as shown in Table 1.

Table 1 User bandwidth demand assumptions

It can be seen from Table 1 that in order to facilitate the calculation and select the corresponding number of WiMAX base station deployment points, three user models inside different building types are proposed. In order to simplify the design, the possible voice and video The business has different requirements for IP ingress bandwidth, but the bandwidth requirements of each typical customer are given in a unified manner. The calculated bandwidth requirements for the entire region are representative and can be modified according to the actual situation in the future. The final result of the user bandwidth demand assumption is as follows:

There are 6 high-rise buildings, and the bandwidth requirements of each building are:

(80*0.4*512*1/3)+(80*0.6*1024*1/4)＝18Mbps, then the total bandwidth is 18*6＝108Mbps;

There are 7 middle-level buildings, as shown in Figure 5, the middle-level buildings 1', 2', 3', 4', 5', 6' and 7', and the bandwidth requirements of each building are: (40*0.5*5 12 *1/3)+(40*0.5*1024*1/4)＝8.5Mbps, then the total bandwidth is 8.5*7＝60Mbps;

There are 2 concentrated areas of residential buildings, and each concentrated area is calculated as 30 residential buildings, then the bandwidth demand of each building is: (10*0.6*512+10*0.4*1024)*1/3=2.5 Mbps, the total bandwidth of each concentrated area is 2.5*30=75Mbps.

According to the location of the buildings, the following 6 locations are initially selected as the BTS deployment locations of the base stations. The 6 high-rise buildings are the first plan, which is most conducive to deploying the WiMAX wireless network system from a height. Achieve building coverage.

For the user bandwidth requirements of middle-rise buildings (8.5Mbps), it is completely possible to use a 3.5MHz single carrier frequency sector (theoretical bandwidth is 12Mbps) to cover the user requirements; and for the user bandwidth requirements of high-rise buildings (18Mbps), Then use two 3.5MHz carrier frequencies (theoretical bandwidth is 24Mbps) to cover at the same time to meet user needs. Therefore, the optimal station selection and station type selection in Fig. 5 are obtained. As shown in table 2.

site location Station type The number of carrier frequencies Site 501 - Tall Building 1 3*60 degree sectors 3*3.5MHz Site 502 - Tall Building 2 3*60 degree sectors 3*3.5MHz Site 503 - Tall Building 3 4*60 degree sector 4*3.5MHz Site 504 - Tall Building 4 2*60 degree sectors 2*3.5MHz Site 505 - Tall Building 5 2*60 degree sectors 2*3.5MHz Site 506 - Tall Building 6 5*60 degree sector 5*3.5MHz (1V, 2V, 3V, 1H, 2H) (H stands for horizontal polarization, V stands for vertical polarization),

Table 2 Covered stations and station types in the central urban area

Among the site deployments listed in Table 2, it can meet the minimum requirements that high-rise buildings are covered by two 3.5MHz carrier frequencies, while middle buildings are covered by one 3.5MHz carrier frequency. In order to save the cost of WiMAX base station sites, at the same time The principle of minimizing the number of BTS sites is followed. In this coverage model, a total of 6 BTS base stations can be found, and the number of sectors of each base station is no more than 5 (site 6). Considering the number of 3*3.5MHz frequency points, different frequency points are used at the same time. The polarization method further increases the frequency reuse capability, so that the 6 carrier frequencies we get can fully meet the coverage of this type of station.

Various modifications can be made to the above contents by those skilled in the art without departing from the spirit and scope of the present invention defined by the claims. Therefore, the scope of the present invention is not limited to the above description, but is determined by the scope of the claims.

Claims (6)

1, a kind of method utilizing multiple 802.16d base stations to densely cover user groups, is characterized in that, comprises the following steps: Step 1, base station interference isolation under the condition of limited frequency resources, which is used to utilize resources and ensure bandwidth required by users; Step 2, the user terminal scans the downlink and establishes synchronization with the base station; the user terminal extracts transmission parameters from the uplink channel descriptor; the user terminal performs ranging; the user terminal automatically selects a strong signal according to the signal strength indication a base station, configured to enable the user terminal to automatically access a strong signal base station; Step 3, performing unified database management on user terminal authentication parameters, for unified management of the user terminal authentication; When the user terminal is in the blind area of the 802.16d base station, the user terminal is handed over to the existing mobile network. 2. The method for densely covering a user group with multiple 802.16d base stations according to claim 1, wherein the isolation in step 1 includes frequency isolation, distance isolation, polarization isolation, direction isolation and/or building Object blocking isolation. 3. The method for using multiple 802.16d base stations to densely cover a user group according to claim 1, wherein the parameters of user terminal authentication are stored in Extensible Markup Language. 4. The method for using multiple 802.16d base stations to densely cover a user group according to claim 3, characterized in that the parameters of the user terminal authentication are queried and obtained through the light directory access protocol. 5. The method for densely covering a user group with multiple 802.16d base stations according to claim 1, wherein the strong signal base station is the base station with the strongest signal. 6. A system that utilizes multiple 802.16d base stations to densely cover user groups, characterized in that the system includes: The isolation module is used for base station interference isolation under the condition of limited frequency resources, so as to utilize resources and ensure the bandwidth required by users; The user terminal is used to scan the downlink and establish synchronization with the base station; it is used to extract transmission parameters from the uplink channel descriptor; The terminal automatically connects to the strong signal base station; A unified authentication module, used for unified database management of user terminal authentication parameters; A switching module, configured to switch the user terminal to an existing mobile network when the user terminal is in a blind area of an 802.16d base station.

Images