CN102186244B - Wireless heterogeneous network system and uniform position management method for wireless heterogeneous networks - Google Patents

Abstract

The invention provides a wireless heterogeneous network system capable of realizing unified location management of wireless heterogeneous networks simply and effectively and a method for unified location management of wireless heterogeneous networks. The wireless heterogeneous network system of the present invention includes various heterogeneous networks, user terminals, a unified mobility management database, and an upper-layer gateway corresponding to each heterogeneous network. The upper-layer gateway includes a location update module and a call processing module; the unified mobility The management database only stores the geographic location coordinates of the user terminal, and does not need to place all network location information of the user terminal, which reduces the requirements for database nodes; in the process of location update processing, only one network needs to be arbitrarily selected for reporting, instead of all All access networks perform location update processing, which greatly reduces the resource overhead of wireless links.

Description

Wireless heterogeneous network system and wireless heterogeneous network unified location management method

technical field

The invention belongs to the use of wireless heterogeneous network technology, and in particular relates to the mobility management of users in the heterogeneous network.

Background technique

In the past 10 years since the development of mobile communication from 2G to 3G, many different wireless transmission technologies have been produced, such as GSM (Global System for Mobile Communications, a technical standard for the second generation of wireless communication), CDMA (Code Division Multiple Access, A second-generation wireless communication technical standard), WCDMA (Wideband Code Division Multiple Access, a third-generation wireless communication technical standard), CDMA2000 (Code Division Multiple Access 2000, a third-generation wireless communication technical standard ), TD-SCDMA (Time Division Synchronous Code Division Multiple Access, a third-generation wireless communication technical standard), 802.11a/b/g, etc., and currently countries are studying the new B3G (super 3rd generation mobile communication system) and 4G (4th generation mobile communication system) transmission technology. Obviously, the future wireless network will be a hybrid network composed of various heterogeneous networks.

Location management technology is one of the key technologies in wireless network mobility management, which is used to track, store, find and update the location information of moving objects. Location management includes two processes of positioning and paging: positioning (location update) refers to the process of the mobile object reporting its location change to the network system, and paging (location query) is the process of the network system finding the location of the mobile object.

Most of the existing and widely used location management technologies are proposed for homogeneous networks, which are not fully applicable to hybrid networks composed of heterogeneous networks.

In view of the characteristics of network heterogeneity, existing scholars have also proposed many solutions: some scholars proposed to join the Internet gateway for corresponding processing to adapt to the location management method of heterogeneous networks with mixed networks (see literature Assouma, A.D., Beaubrun, R ., Pierre, S..Mobility management in heterogeneous wireless networks[J]IEEE Journal on Selected Areas in Communications, 2006, 24(3):638-648), but this method needs to establish devices between two networks, which is too complicated , the scalability of the network is not good; there is also a unified mobility management (UMM) technology proposed, which uses a super database (super HLR) to achieve multi-protocol location management, and the central management node at the UMM end will store each All network location information such as the GSM location area of the mobile user, the home agent address of the MIP (Mobile Internet), and the target router address of the WLAN (Wireless Local Area Network) need to be updated for all access networks when updating the location of the mobile user. Location management operations, (see Haase, O., Ming Xiong; Murakami, K. Multi-protocol profiles to support user mobility across network technologies[C]. Proceedings of the 2004IEEEInternational Conference on Mobile Data Management, 2004: 100-105), Although this method better realizes the location management function of the heterogeneous network, it needs to re-establish a central management node with high performance requirements. The data storage scale of the central management node is large and the cost is high; when updating the location The overhead of the wireless link is large, and it does not have good scalability.

Contents of the invention

The technical problem to be solved by the present invention is to provide a wireless heterogeneous network system and a method for unified location management of the wireless heterogeneous network that can simply and effectively realize the unified location management of the wireless heterogeneous network.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is that the wireless heterogeneous network system includes various heterogeneous networks, user terminals, a unified mobility management database, and an upper-layer gateway corresponding to each heterogeneous network. The gateway includes a location update module and a call processing module;

The user terminal is used to perform autonomous positioning periodically to obtain the geographic location coordinates of the user terminal, and then select a wireless network, and send a location update report to a location update module in the selected wireless network; the location update report includes user The geographic location coordinates of the terminal and the user identification; the geographic location coordinates of the user terminal are composed of the longitude and latitude where the user terminal is located; when the user terminal is the calling user terminal, the calling user terminal selects a wireless network to send a call request, and the The call request includes the identification of the calling user and the identification of the called user; when the user terminal is the called user terminal, the called user terminal returns a call response after receiving the call request;

The unified mobility management database is used to, after receiving the location update report, extract the geographic location coordinates of the user terminal, and store them under the user identifier corresponding to the user terminal; after receiving the paging request, according to the called user terminal Find the corresponding geographic location coordinates of the user ID, and return the geographic location coordinates of the called user terminal to the call processing module corresponding to the wireless network selected by the calling user terminal;

The location update module is configured to, after receiving the location update report sent by the user terminal, send the location update report to the unified mobility management database;

The call processing module is used for, when the call processing module is the calling call processing module, after receiving the call request sent by the calling user terminal, the calling call processing module sends a paging request to the unified mobility management database; After the called call processing module receives the geographical location of the called user terminal returned by the unified mobility management database, it adds the called user terminal geographic location in the call request sent to the called call processing module; When processing the module, after the called call processing module receives the call request added with the geographic location of the called user terminal, it extracts the geographic location coordinates of the called user terminal, and calculates the coverage of the called user terminal according to the geographic location coordinates of the called user terminal. Antenna information of the user terminal, and send a call request to the called user terminal.

In the present invention, the internal processing of each heterogeneous network keeps the existing processing method unchanged, and only adds a new processing step of the upper-level gateway after the processing of the mobility management database in each heterogeneous network, and stores in the upper-level gateway of each heterogeneous network There are geographical location coordinates of each location area management node or base station in the network; the user terminal can be either a single-mode user terminal or a multi-mode user terminal; when a single-mode user terminal selects a wireless network, only one wireless network can be selected , the multi-mode user chooses a network within the range of available networks to perform location update or paging.

The wireless heterogeneous network unified location management method applied to the above system includes user location update processing and user paging processing, and is characterized in that the user location update processing includes the following steps:

a1. The user terminal performs autonomous positioning periodically to obtain the geographic location coordinates of the user terminal; the geographic location coordinates of the user terminal are composed of longitude and latitude where the user terminal is located;

a2. The user terminal selects a wireless network, and sends a location update report to the location update module in the selected wireless network, and the location update report includes the geographic location coordinates of the user terminal and the user identification;

a3. After receiving the location update report, the location update module forwards the location update report to the unified mobility management database;

a4. After receiving the location update report, the mobility management database extracts the geographic location coordinates of the user terminal and stores them under the user identifier corresponding to the user terminal;

The user paging process includes the following steps:

b1. The calling user terminal selects a wireless network to send a call request, and the call request includes the calling user ID and the called user ID;

b2. After receiving the call request, the call processing module at the calling end sends a paging request to the unified mobility management database, where the paging request includes the user identifier of the called user terminal;

b3. After the unified mobility management database receives the paging request, it searches for the corresponding geographic location coordinates according to the user identification of the called user terminal, and returns it to the calling terminal call processing module;

b4. The calling call processing module adds the geographic location coordinates of the called user in the sending call request, and sends the call request adding the geographic location coordinates of the called user to the called terminal call processing module;

b5. After the call processing module of the called terminal receives the call request added with the geographic location coordinates of the called user, it extracts the geographic location coordinates of the called user terminal, and calculates the coverage of the called user terminal according to the geographic location coordinates of the called user terminal antenna information and send a call request to it;

b6. After receiving the call request, the called user terminal returns a call response, and the calling user terminal establishes a communication link with the called user terminal.

The unified mobility management database of the present invention only stores the geographic location coordinates of the user terminal, and does not need to store all network location information of the user terminal, which reduces the requirements for database nodes; only one network needs to be arbitrarily selected during the location update process. report, instead of performing location update processing on all access networks, which greatly reduces the resource overhead of the wireless link. In the paging phase, the call processing modules of various heterogeneous networks perform distributed processing, without changing the internal location management processing flow of the existing network, and have good scalability and compatibility.

Specifically, the user identifier is a user number.

Specifically, the user terminal performs autonomous positioning according to network broadcast information. More specifically, the user terminal performs positioning according to the broadcast information of a certain network, or performs joint positioning according to the broadcast information of several networks. For example, the user terminal uses a time-based periodic algorithm to perform GPS (Global Positioning System) positioning processing.

In order to further reduce the wireless link overhead during location update, after step a1 and before step a2, the user terminal also performs a pre-judgment process on whether to send a location update report, and the user terminal compares the geographic location coordinates of the last location update with the local Whether the geographical position coordinates obtained this time meet the position update standard, if yes, then enter step a2, if not, then return to step a1; in step a2, the user terminal is locally replaced with the geographical position coordinates obtained this time while sending the position update report Geolocation coordinates at the time of the last location update and store. In this way, when the user terminal does not change greatly within a period, the user terminal does not initiate a location update report, which greatly reduces the wireless link overhead in the hybrid network.

The beneficial effect of the present invention is that it can well complete the location management of the heterogeneous network without changing the location management processing method inside the existing network, and has good compatibility; new emerging networks in the future can also use this method Completing the location management function, it has good openness; there is no too complicated conversion to limit the network scale, and it has good scalability. Although the location information of the user terminal is also stored in the UMM (Unified Mobility Management) database, because the location information is stored, it is not all network location information (for example, the location area of GSM, the home agent address of MIP, the WLAN address of the target router), so compared with the existing UMM database, the data storage scale of the database will be greatly reduced; and because the location update process only selects the most suitable network for one operation, not all accessible networks. location management operations, so the overhead on the wireless link is also greatly reduced.

Description of drawings

FIG. 1 is a schematic diagram of a heterogeneous network system of the present invention;

Figure 2 is a specific wireless heterogeneous network scenario in this implementation;

Fig. 3 is the location update processing steps of the present invention;

Fig. 4 is the call processing steps of the present invention;

Fig. 5 is the storage scale comparison of the embodiment of the present invention and the existing unified location management database;

FIG. 6 is a comparison of the wireless link overhead between the embodiment of the present invention and the existing unified location management.

Detailed ways

As shown in Figure 1, the wireless heterogeneous network system includes various heterogeneous networks (GSM network, UNTS network, WLAN, satellite network and other new networks), a unified mobility management database, and an upper-layer gateway corresponding to each heterogeneous network setting , the upper layer gateway includes a location update module and a call processing module; the internal structure and processing of each heterogeneous network remain unchanged according to its protocol, such as the existing GSM network includes a base station (BS), a mobile switching center (MSC), and a home location register (HLR) , Visitor Location Register (VLR), the existing UNTS (Universal Mobile Telecommunications System) network includes Base Station (BS), Node B (B node), RNC (Radio Network Controller), and the existing WLAN (Wireless Local Area Network) includes AP ( Access Point), MAP (Mobile Application Part), the existing satellite network includes satellite and ground gateway stations. The present invention only adds the processing steps of the new upper layer gateway after the mobility management processing in each heterogeneous network, the mobility management processing is completed by the HLR/VLR in the existing GSM network, and is completed by the RNC in the existing UNTS network, now It is completed by MAP in some WLANs, and it is completed by ground gateway stations in existing satellite networks. The upper layer gateways of each heterogeneous network store the geographic location coordinates of each location area management node or base station in the network.

The implementation method of the present invention in a specific wireless heterogeneous network scenario is given below:

As shown in Figure 2, user 1 is an airborne user, has no ground network coverage, and can only access it through maritime satellites. User 2 is a ground mobile user and is covered by GSM network, WLAN and satellite network at the same time, and each network is always equipped with its upper layer gateway. Two users engage in remote video communication. The upper-layer gateway of the satellite network has obtained the satellite ephemeris information and can calculate the specific position coordinates of the satellite at a certain moment. The upper-layer gateway of the WLAN has obtained the location coordinates of each wireless access point (AP) in the network. The upper-layer gateway of the GSM network has Obtain the position coordinates of MSC and base station in the network; both user 1 and user 2 are multi-mode terminals, which can access one or more wireless networks in the form of software radio, and can switch vertically between different networks; unify the location The management database can communicate with the upper gateways of all networks, and store data such as user location information.

The processing flow of the location update stage is shown in Figure 3:

1. The terminals of the airborne user 1 and the ground user 2 respectively perform independent positioning according to a certain algorithm periodically according to the broadcast information of the network, and respectively obtain their own geographic location coordinates (X1, Y1), (X2, Y2);

2. The user judges whether to initiate the location update process based on the location coordinates of the last location update recorded by the user and the coordinates measured this time. If the location update process needs to be initiated, enter step 3, and if not, return to step 1;

其中，r为两坐标的距离，X1为上一次位置更新时的经度、Y1为上一次位置更新时的纬度，X2为本次得到的经度、Y2为本次得到的纬度。阈值的取值为

其中，R为阈值，v为用户终端的速率，C_U为一次位置更新操作的无线链路开销，C_P为一次寻呼操作的无线链路开销，λ为用户终端的呼叫到达率；The user terminal compares whether the distance between the geographic location coordinates of the last location update and the geographic location coordinates obtained this time is greater than a threshold to determine whether the location update standard is met. If it is larger, the location update standard is met, otherwise it is judged as not meeting the location update Standard; the distance between the geographic coordinates of the last location update and the geographic coordinates obtained this time is

Among them, r is the distance between the two coordinates, X1 is the longitude of the last location update, Y1 is the latitude of the last location update, X2 is the longitude obtained this time, and Y2 is the latitude obtained this time. The value of the threshold is

Among them, R is the threshold value, v is the speed of the user terminal, C _U is the wireless link overhead of a location update operation, C _P is the wireless link overhead of a paging operation, and λ is the call arrival rate of the user terminal;

3. Airborne user 1 selects the satellite network to initiate a location update report. The location update report contains its own user ID and geographic location coordinates (X1, Y1). The location update report is sent to the ground gateway station through the satellite, and then passed through the upper gateway. Ground user 2 selects the GSM network with good coverage, and sends its own position coordinates (X2, Y2) to the HLR (Home Location Register) through the base station and MSC (Mobile Switching Center) by initiating a position update report ), and then processed by the location update module in the upper-layer gateway, both users record the coordinates locally at the terminal and delete the last record; the location update modules in the two upper-layer gateways send location update reports to the UMM database respectively, and the user The identifier id1 and the corresponding coordinates (X1, Y1), the user identifier id2 and the corresponding coordinates (X2, Y2) are sent to the UMM database;

4. After receiving the report, the upper layer gateways of the network where the two users are located send the user's position coordinate data (X1, Y1) and (X2, Y2) and the user identification id1, id2 of the two users to the UMM database;

5. After receiving the information, UMM records the user's location coordinates under their respective user IDs.

The processing of the user paging phase is shown in Figure 4:

1. The airborne calling user 1 only has satellite coverage, so the satellite network (network 1) is selected to make a call, and a call request is sent to the network through the satellite. The call request includes information calling identification id1 and called identification id2;

2. After the network 1 call gateway receives the call request, it sends a paging request to the UMM database to query the geographic location coordinates of the called user, and the paging request includes the called identifier id2;

3. The UMM database returns the location coordinates (X2, Y2) of the called user 2 to the network 1 call module;

4. The network 1 call gateway selects a WLAN with relatively large bandwidth as the called network according to the service type (video) to access, and sends a call request to the upper gateway of the WLAN (network 2 call module). The call request here also includes coordinate(X2, Y2);

5. After receiving the second call request, the network 2 call module obtains the IP address of the access point according to the called user's position coordinates (X2, Y2), and sends a call request to the called user through the AP;

6. After receiving the call request, the called user 2 returns a call response, establishes a link, and performs data transmission.

The UMM database of the present invention only stores user geographic location information (latitude and longitude), and does not store user identification and geographic location coordinates at each heterogeneous network gateway; The station number, the location area number and base station number of the cell, the IP address of the router to which the WLAN belongs, and other network location information; and although there is no central node in the Internet gateway architecture, each heterogeneous network will independently store its corresponding information. According to the test results, the storage scale of the UMM database of the present embodiment only needs 0.3 times of the sum of the independent databases under the central database scale or Internet shopping framework of the existing UMM framework, which can well complete the normalized location management, such as Figure 5 shows. In the location update stage, the present invention reports geographic location coordinates, so it only needs to arbitrarily select a suitable network for location update processing, while the other two existing methods need to update the location information of each heterogeneous network at the same time, so Location updates are required on all networks that the user can access. In the example shown in Figure 2, there are 3 kinds of networks that user 2 can choose to access. The existing location update method requires three update operations, while the location update method of the present invention only needs to perform one update operation. The wireless link overhead is 0.3 times that of the location update method under the existing UMM framework and Internet shopping framework, as shown in FIG. 6 .

Claims (10)

1. The wireless heterogeneous network system comprises various heterogeneous networks and a user terminal, and is characterized by also comprising a unified mobility management database and an upper gateway which is arranged corresponding to each heterogeneous network, wherein the upper gateway comprises a position updating module and a call processing module;

the user terminal is used for periodically carrying out autonomous positioning to obtain the geographical position coordinates of the user terminal, then selecting a wireless network and sending a position updating report to a position updating module in the selected wireless network; the location update report comprises the geographical location coordinates of the user terminal and a user identifier; the geographical position coordinates of the user terminal consist of longitude and latitude of the user terminal; when the user terminal is a calling user terminal, the calling user terminal selects a wireless network to send a calling request, wherein the calling request comprises a calling user identifier and a called user identifier; when the user terminal is the called user terminal, the called user terminal returns a call response after receiving the call request;

the unified mobile management database is used for extracting the geographic position coordinates of the user terminal after receiving the position updating report and storing the geographic position coordinates in the user identifier corresponding to the user terminal; after receiving the paging request, searching the corresponding geographic position coordinate according to the user identification of the called user terminal, and returning the geographic position coordinate of the called user terminal to the call processing module corresponding to the wireless network selected by the calling user terminal;

the location updating module is used for sending a location updating report to the unified mobility management database after receiving the location updating report sent by the user terminal;

the call processing module is used for sending a paging request to the unified mobility management database after receiving a call request sent by a calling user terminal when the call processing module is a calling call processing module; after receiving the geographic position of the called user terminal returned by the unified mobility management database, the calling call processing module adds the geographic position of the called user terminal in a call request sent to the called call processing module; when the call processing module is a called call processing module, the called call processing module extracts the geographic position coordinate of the called user terminal after receiving the call request added with the geographic position of the called user terminal, calculates the antenna information covering the called user terminal according to the geographic position coordinate of the called user terminal, and sends the call request to the called user terminal.

2. The wireless heterogeneous network system of claim 1, wherein the autonomous positioning performed by the ue specifically comprises: and positioning is carried out according to the broadcast information of a certain network, or joint positioning is carried out according to the broadcast information of several networks.

3. The wireless heterogeneous network system of claim 1, wherein the ue is further configured to, after obtaining the geographical location coordinates of the ue, perform a pre-determination process on whether to initiate a location update report before sending the location update report to the location update module in the selected wireless network: when the geographical position coordinate during the last position updating and the geographical position coordinate obtained this time accord with the position updating standard, sending a position updating report, and if not, not sending the position updating report; and the user terminal replaces the geographical position coordinate obtained at the time of the last position updating with the geographical position coordinate obtained at the time of sending the position updating report and stores the geographical position coordinate.

4. The wireless heterogeneous network system according to claim 3, wherein the ue is further configured to determine whether the location update criterion is met by comparing whether a distance between the geographical location coordinate at the last location update and the geographical location coordinate obtained this time is greater than a threshold, and if so, the location update criterion is met, otherwise, the location update criterion is not met; the distance between the geographical position coordinate at the last position updating and the geographical position coordinate obtained this time isWhere r is a distance between two coordinates, X1 is a longitude at the time of the last location update, Y1 is a latitude at the time of the last location update, X2 is a longitude obtained this time, and Y2 is a latitude obtained this time.

5. The wireless heterogeneous network system of claim 4, wherein the threshold value is set to a valueWherein,r is a threshold value, v is the rate of the user terminal, C_URadio link overhead for one location update operation, C_Pλ is the call arrival rate of the user terminal, which is the radio link overhead for one paging operation.

6. The unified location management method of the wireless heterogeneous network comprises user location updating processing and user paging processing, and is characterized in that the user location updating processing comprises the following steps:

a1, the user terminal periodically carries out autonomous positioning to obtain the geographic position coordinates of the user terminal; the geographical position coordinates of the user terminal consist of longitude and latitude of the user terminal;

a2, selecting a wireless network by the user terminal, and sending a location update report to a location update module in the selected wireless network, wherein the location update report comprises the geographical location coordinates of the user terminal and the user identification;

a3, after receiving the location update report, the location update module forwards the location update report to the unified mobility management database;

a4, after receiving the position update report, the mobile management database extracts the geographical position coordinates of the user terminal and stores the coordinates in the user identifier corresponding to the user terminal;

the user paging processing comprises the following steps:

b1, the calling user terminal selects a wireless network to send a call request, wherein the call request comprises a calling user identifier and a called user identifier;

b2, after receiving the call request, the calling call processing module sends a paging request to the unified mobility management database, wherein the paging request comprises the user identification of the called user terminal;

b3, after receiving the paging request, the unified mobility management database searches the corresponding geographical position coordinate according to the user identification of the called user terminal, and returns the geographical position coordinate to the calling call processing module;

b4, the calling call processing module adds the geographical position coordinates of the called user in the call sending request, and sends the call request added with the geographical position coordinates of the called user to the called call processing module;

b5, after receiving the call request added with the geographic position coordinate of the called user, the called call processing module extracts the geographic position coordinate of the called user terminal, calculates the antenna information covering the called user terminal according to the geographic position coordinate of the called user terminal and sends the call request to the antenna information;

b6, after receiving the call request, the called user terminal returns a call response, and the calling user terminal and the called user terminal establish a communication link.

7. The unified location management method for wireless heterogeneous network as claimed in claim 6, wherein the autonomous positioning performed by the ue specifically comprises: and positioning is carried out according to the broadcast information of a certain network, or joint positioning is carried out according to the broadcast information of several networks.

8. The unified location management method for wireless heterogeneous networks according to claim 6, wherein after step a1 and before step a2, the ue performs a pre-determination process on whether to send a location update report, and the ue compares the geographical location coordinate of the last location update with the geographical location coordinate obtained this time to see whether they meet the location update criteria, if yes, it goes to step a2, if no, it goes back to step a 1; in step a2, after sending the location update report, the user terminal locally replaces the geographical location coordinate obtained this time with the geographical location coordinate obtained last time and stores the geographical location coordinate.

9. The unified location management method for wireless heterogeneous networks according to claim 8, wherein the ue determines whether the location update criterion is met by comparing whether the distance between the geographical location coordinate at the last location update and the geographical location coordinate obtained this time is greater than a threshold, if so, the location update criterion is met, otherwise, the location update criterion is not met; geographical position at last location updateThe distance between the set coordinate and the geographical position coordinate obtained this time isWhere r is a distance between two coordinates, X1 is a longitude at the time of the last location update, Y1 is a latitude at the time of the last location update, X2 is a longitude obtained this time, and Y2 is a latitude obtained this time.

10. The unified location management method for wireless heterogeneous network according to claim 9, wherein the threshold value is set to a value of

Where R is the threshold, v is the rate of the user terminal, C_URadio link overhead for one location update operation, C_Pλ is the call arrival rate of the user terminal, which is the radio link overhead for one paging operation.

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