WO2006051469A1

WO2006051469A1 - A location management system and method

Info

Publication number: WO2006051469A1
Application number: PCT/IB2005/053637
Authority: WO
Inventors: Xiaohui Jin; Xiaoling Shao; Bo Liu
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2004-11-09
Filing date: 2005-11-07
Publication date: 2006-05-18
Also published as: TW200723754A

Abstract

The invention proposes a location management system and method of a wireless overlay network and the applicable mobile station. The local management system comprises: a first wireless network (1) which includes a home location register (101) for storing the location information (1010) of the first wireless network and the location information (1011) of a second wireless network, a Convergence Point (110) connected with said home location register (101); a second wireless network (2) connected with the first wireless network (1) via said Convergence Point (110), wherein said first wireless network (1) and said second wireless network (2) can access the mobile station (MS1) based on the location information (1010) of the first wireless network and the location information (1011) of the second wireless network respectively, and the mobile station can obtain the services of the first wireless network (1) and the second wireless network (2) at the same time.

Description

ALOCATION MANAGEMENT SYSTEMAND METHOD

FIELD OF THE INVENTION

5 The invention relates to a wireless overlay network, and more particularly, to a location management system and method of the wireless overlay network, and to a mobile station adapted to use with the location management system of the wireless overlay network.

[ 0 BACKGROUND OF THE INVENTION

Compared with the WLAN, the current cellular network (2G/2.5G/3G), which acts as a public network, is more advantageous in the aspects of mobility, roaming, full coverage etc., while WLAN could provide high speed data transmission service with low mobility, which could complement the 2G/2.5G/3G cellular network.

15 In the view of the techniques, GPRS (General Packet Radio Service), for example, which transmitting distance is up to several to tens of kilometers, has a lower transmission rate, and the highest rate is 171.2Kbps in theory. While the WLAN has a higher transmission rate, for example, the highest transmission rate that the 8OLl Ig supports is 54Mbps, but it has a short transmission distance about 100 meters. When the user is in the

10 environment of high mobility and requires low rate and less resource, he can use products such as handsets and PDAs etc. to access the Internet via GPRS, but has to pay considerable fees. When the user is in the environment of low mobility and requires high rate and more resources, he can use the products such as notebooks, tablet computer etc. or the handsets, PDAs etc. equipped with WLAN module to access the Internet via WLAN

£5 and the fees is lower.

WLAN + GPRS scheme could combine the advantages of these two wireless networks very well, as shown in the Fig.1. Fig.1 is a schematic diagram of the network structure combining the WLAN and GPRS network, in which WLAN 2 is connected with the GPRS network 1 as a whole through SGSN (Serving GPRS Supporting Node) 110.

SO WLAN 2 accesses the GPRS network 1 through a standard interface in a same manner as the other access networks, the WLAN data is forwarded via GPRS, and the authorization, authentication and billing is implemented by the way of GPRS. A similar network structure as described above is disclosed in PCT patent application WO 3/105380 Al published on December 18 2003, which includes a network interface connecting the PLMN (Public Land Mobile Network) network and WLAN. Such a network interface includes duplex mode of the PLMN protocol and WLAN protocol to connect the PLAM and the WLAN network seamlessly.

In the cellar network such as GPRS, Location management is a very important function, which includes updating the mobile station MSl' location information and providing the location of the mobile station MSl in the network in time, so that the phone calls or the data packets are transferred to the mobile station MSl . In the GPRS network 1, for each of mobile station MSl, it has only one unique location identity 1010, which includes some following location information or part of it: IMSI (International Mobile Subscriber Identity), TMSI (Temporary Mobile Subscriber Identity), LMSI (Local Mobile Subscriber Identity), IMEI (International Mobile Equipment Identity) etc. After the mobile station MSl is power on and was registered in , the MSC/VLR 100 or SGSN 110 of GPRS network 1, or when the mobile station MSl is handovering or roaming, it is necessary to update the location information, and the latest location information is updated into HLR 101, VLR 100, SGSN 110, and the original old location information is removed at the same time.

In the GPRS + WLAN wireless overlay network as described above, it is possible for a mobile station MSl to handover between the GPRS network 1 and WLAN 2. Because

WLAN 2 data are all forwarded through GPRS (i.e. through a path GGSN -» SGSN ^■» Gateway/Router -^ AP -> MSl), the main problem lies in that when the mobile station MSl is registered only in the this GPRS network 1, there is only one unique location identity 1010 stored in the HLR 101 at the same time. It is impossible to access this mobile station MSl via WLAN (i.e. to send to the mobile station MSl via AP), that is, although

MSl is simultaneously within the coverage area of the WLAN 2 at this time, the data of the WLAN 2 can only be forwarded via GPRS network. When the mobile station MSl is registered only in the WLAN 2, it is also impossible to access this mobile station MSl via GPRS, because at this time there is no updated location information of the mobile station MSl in the HLR 101, which means that the mobile station MSl can not obtain the CS/PS

(Circuit Switch/Packet Switch) service of the GPRS network 1 and the network service of the WLAN 2, simultaneously. OBJECT AND SUMMARY OF THE INVENTION

In order to overcome the disadvantage that mobile station can not obtain the CS/PS service of the GPRS network and the service of the WLAN simultaneously in the prior art, one objective of the invention is to provide a location management system and method of a wireless overlay network, which enables the GPRS network to keep both the GPRS network location information and the WLAN location information of the mobile station at the same time, so that the mobile station can obtain the CS/PS service of the GPRS network and the service of the WLAN simultaneously.

Another objective of the invention is to provide a mobile station for location management in the wireless overlay network, so that the mobile station can obtain the

CS/PS service of the GPRS network and the network service of the WLAN simultaneously.

In accordance with one embodiment of the invention, there provides a location management system of a wireless overlay network for managing location information of mobile station in the wireless overlay network, which comprises: a first wireless network including: a home location register for storing the location information of the first wireless network and the location information of a second wireless network; a Convergence Point connected with said home location register; the second wireless network connected with the first wireless network via said Convergence Point; wherein said first wireless network and said second wireless network can access the mobile station based on the location information of the first wireless network and the location information of the second wireless network , respectively.

A method for updating the location information of a wireless overlay network is provided according to the invention, the method comprising the following steps: registering a mobile station in a first wireless network to obtain the location information of the first wireless network and storing it in the home location register of the first wireless network; registering the mobile station in a second wireless network to obtain the location information of the second wireless network; and the mobile station sending the location information of the second wireless network and storing it in the home location register.

A communication method of the wireless overlay network is provided according to the invention, which comprises: A communication method for a wireless overlay network, comprising the steps of: registering a mobile station in a GPRS network to obtain location information of a first wireless network and storing it in HLR; registering the mobile station in a WLAN to obtain location information of a second wireless network; sending the location information of the second wireless network to the HLR.

A mobile station comprises: A first wireless network module, which can be registered in a first wireless network to obtain the location information of the first wireless network; A second wireless network module, which can be registered in a second wireless network to obtain the location information of the second wireless network; wherein said mobile station can send said location information of the second wireless network and store it in a home location register of the first wireless network.

As a summary of above, the invention provides a location management system and method of wireless overlay network, by which a call or data packet can arrive at the mobile station through different paths of GPRS or WLAN, i.e. enabling the mobile station to obtain services of two different wireless overlay network, so that the content of the service the mobile station could obtain are more abundant.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a typical schematic diagram of the network structure combining the WLAN and GPRS network.

Fig. 2 is a schematic diagram of the network structure combining the WLAN and GPRS network according to the invention. Fig. 3 is a schematic diagram of the process of updating the location information according to the invention.

Fig. 4 is a schematic diagram of the packet transmission process and the call establishment process according to the invention.

Fig. 5 is the schematic diagram of the function module of the mobile station according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In order to understand the management of location information by the GPRS + WLAN involved in the embodiment of the invention more clearly, the complete process will be first described briefly that the GPRS network stores, sends and updates the various location information of the mobile station, with reference to the Fig. 2.

Fig. 2 is a schematic diagram of the network structure of the location management system of a wireless overlay network according to the invention, wherein WLAN 2 accesses GPRS network 1 through SGSN 110, SGSN 110 is referred to as Convergence Point herein. For the system and method provided by the invention, Convergence Point can also be the GGSN (Gateway GPRS Supporting Node) 111 or MSC (Mobile Switch Center) 100. In this embodiment, if not specified, the technical scheme of the invention is

5 described by always using SGSN 110 as the example of Convergence Point.

GPRS network 1 includes CS (Circuit Switch) domain 10 and PS (Packet Switch) domain 11, CS domain 10 deals with the conventional circuit switch service, such as speech service, which requires to occupy some resources to establish a dedicated link at every communication; PS domain 11 deals with packet switch service, which does not

0 require the establishment of a dedicated link, and each packet can find the route by itself.

Included in the CS domain 10 are MSC (Mobile Switch Center)/VLR (Visit Location Register) 100 and HLR (Home Location Register)/AuC (Authentication Center)/EIR (Equipment Identity Register) 101. In the GPRS network 1, HLR 101 provides the initial identity information of the MS 1, updates the location information of

[5 the MSl in time, and corresponds the IMSI (International Mobile Subscriber Identity) and

SGSN address to one or more pairs of PDP (Packet Data Protocol) type or PDP address, meanwhile, HLR 101 also stores the mapping relationship between the GGSN and PDP address/type. VLR (Visit location register) is used to store the temporary location information of the MS 1. MSC/VLR 100 may connect to the other PLMN (Public Land

»0 Mobile Network) 3.

PS domain 11 mainly includes SGSN 110 and GGSN (Gateway GPRS Supporting Node) 111. The main functions of SGSN (Serving GPRS Supporting Node) 110 are, among other things, to detect the new GPRS mobile station MS 1 in its service area, to send data packets to the MS land/or receive data packets from the mobile station MSl, and to

15 record the location of the mobile station MSl in its service area. The main functions of

GGSN 111 include interaction with the external data network such as INTERNET 4, which updates the location directory by using route information associated with the path of MSl provided by SGSN 110, and the received data packet is transmitted to the SGSN 110 currently serving for the MSl through GPRS backbone network.

50 WLAN 2 comprises Gateway/Router 20 and AP (Access Point) 21, in which

Gateway/Router 20 connects to SGSN 110 to access GPRS network 1, and AP 21 is used for sending the data to the mobile station MS2. Mobile station MSl can be various handsets, PDAs that has with WLAN and GPRS access function or other wireless terminals with WLAN access function.

In the GPRS network 1 of the invention, the following information may used to reflect the location of the mobile station MSl: IMSI, TMSI, LMSI, IMEI, LAI (Location Area Identity), RAI (Routing Area Identity), CI (Cell Identity), MSISDN (Mobile Subscriber ISDN Number), MSRN (Mobile Station Roaming Number), P-TMSI (Packet- TMSI), SGSN address, SGSN number, GGSN address, GGSN number, PDP (Packet Data Protocol), MM (Mobile Management) state, etc.. The above information is stored in the different entities in the GPRS network 1 respectively, and the detailed distribution list of which can be seen from Table 1.

The invention provides a solution for managing a plurality of non-unique location information. In an embodiment of the invention, not only the location information of the mobile station MSl in the GPRS network 1, such as the information of CI, MSC/VLR etc., shown in Table 1, but the location information of the mobile station MSl in the WLAN 2 such as WLAN network name, IP address of the WLAN, NAI (Network Access Identifier) of the mobile station MS2 in the WLAN are stored in HLR 101; VLR 100, SGSN 110 and GGSN 111 may connect to and communicate with the HLR 101 to obtain the updated location information of the mobile station MSl.

Table 1

When the Convergence Point of GPRS network 1 and WLAN 2 is SGSN 110, the location information described above is stored in different entities in the GPRS network 1 and the distribution thereof is shown in Table 2, compared with Table 1, the only difference is that the location information stored in the HLR, SGSN and MS are different, the location information stored in the other entities are totally same with those listed in Table 1, thus they are omitted in Table 2.

Table 2

When the Convergence Point of GPRS network and WLAN is MSC/BSS, the specific distribution is shown in Table 3, compared with Table 1, the only difference is that the location information stored in the HLR, SGSN and MS are different, the location information stored in the other entities are totally same with those listed in Table 1, thus they are omitted in Table 3.

Table 3

As shown in Fig. 3, it is a schematic diagram of the process of updating the location information in the location management system and method of a wireless overlay network according to the invention. In the wireless overlay network, Convergence Point 120 is an important node for exchanging information. Generally, Convergence Point 120 may have three types of selection: GGSN, SGSN or MSC/BSS. For the reason of clarity, this embodiment illustrates these three types together, referred to generally as Convergence Point 120, the steps of the process for updating the location information are as following:

(a) Mobile station MSl is registered in GPRS network, and HLR 101 stores the location information of the mobile station MSl (Step 301), this process is the same as the conventional approach of the GPRS network, hence it is not described in detail herein;

(b) Mobile station MSl is registered in WLAN 2, and obtains a temporary IP address of WLAN (Step 302);

(c) The mobile station MSl informs the existing location information, such as IP address of WLAN 2, to GPRS network and there are two ways:

(1) informing through GPRS network (Step 303); or

(2) sending the location information, such as IP address of WLAN 2, to Convergence Point 120 by WLAN 2, after the Convergence Point 120 received the updated location information, to update repository and inform this updated location information to the HLR 101 (Step 304).

According to the conventional way of updating, after receiving the updated location information, the Convergence Point 120 and the HLR 101 delete the original location information therein. But, in an embodiment of the invention, after receiving the updated location information, the Convergence Point 120 and the HLR 101 will still store the original location information of GPRS network, thus, the mobile station MSl has two location information stored respectively in the HLR 101 simultaneously, i.e. the calls or the data packets can reach the mobile station MSl through GPRS or WLAN 2 at the same time. (d) If the Convergence Point 120 loses all or part of location information of mobile station MSl, when the call or packet whose destination is the mobile station arrives, Convergence Point 120 can send a query request to the HLR 101, and upon receiving the query request, the HLR 101 sends the latest location information of the mobile station MSl to the Convergence Point 120. As shown in Fig. 4, it is the work flow of the location management method of wireless overlay network according to the invention. In order to understand the multi- location information management of the mobile station in the invention more clearly, the work flow of the invention is described respectively in the following four scenario modes: Scenario Mode A: When the GGSN 110 acts as the Convergence Point, the phone calls or the data packets are transmitted to the destination mobile station MSl with the specific WLAN IP location:

After a data packet whose destination is a specific WLAN IP location arrives at GGSN 110 (Step 401), the GGSN 110 first queries the location information in the HLR

101 repository (Step 402), after receiving the query, the HLR 101 will return the next node address related to a routing rule (Step 403), SGSN 111 then transmits the data packet to the WLAN according to the routing rule (Step 404), WLAN 2 sends in turn the data packet to the mobile station MSl through AP (not shown) (Step 405). Scenario B: When the SGSN 111 acts as the Convergence Point, the phone calls or the data packets are required to be transmitted to mobile destination station MSl with specific GPRS network location:

After a data packet whose destination is a specific GPRS IP location arrives at GGSN 110 (Step 411), the GGSN 110 queries the repository and forwards it to the SGSN 111 according to GTP (GPRS Tunneling Protocol) (Step 412), GGSN 110 queries the HLR

101 repository (Step 413), the HLR 101 returns the location information (Step 414), and SGSN 111 then send the data packet to the mobile station MSl through GPRS network (Step 415).

Scenario Mode C: mobile station MSl initiates a call to MSC When the mobile station MSl initiates a call to MSC 100 (Step 421), after MSC

100 receives the call, the call is transmitted to the destination (Step 422), meanwhile, MSC 100 transmits the current location information of the mobile station MSl to HLR 101 to update the latest GPRS location information of the mobile station MSl (Step 423). Scenario Mode D: MSC receives a CS call After MSC 100 receives a CS call transmitted to mobile station MSl (Step 431),

MSC 100 first queries the HLR 101 for the latest GPRS network location information of the mobile station MSl (Step 432), after receiving the query, the HLR 101 returns GPRS network location information back to MSC 100 (Step 433), MSC 100 transmits the CS call to the mobile station MSl based on the returned GPRS location information (Step 434). As the summary of the four scenario modes described above, when the mobile station MS 1 is within the coverage range of the GPRS network and WLAN, the calls or packets can arrive at the mobile station not only through GPRS network but through WLAN, as two location information of the mobile station MSl are stored in the HLR. The cost for transmission of data packet through WLAN is lower, so a mobile station can select transmission manner with a relatively low cost and high speed by using the approach provided by the invention.

Fig. 5 is the schematic diagram of the function module of the mobile station of the

5 invention. The mobile station MSl includes a baseband module 605, a GPRS radio frequency module 603, a WLAN radio frequency module 604 and a user interface 606. The GPRS radio frequency module 603 and the WLAN radio frequency module 604 mentioned above include a transponder and a receiver (not shown in the figure) connected to respective antenna 601, 602, respectively. The baseband module 605 is used for providing

.0 the forwarding signal to the transponder, which comprises a RAM (Random Access

Memory) 6050, a ROM (Read Only Memory) 6051, a microprocessor 6052 and a DSP 6053. The user interface 606 comprises a microphone 6061, a loudspeaker 6062, a keyboard 6063 and a display 6064. The corresponding software programs for executing the method illustrated by Fig.4 can be stored in the ROM 6051 of the baseband module 605.

[5 It should be understood by the skilled in the art that the location management system and method of the wireless overlay network provided by the invention are not only adapted to use with the GPRS network, but also adapted to use with other 3 G cellular networks.

It should be understood by the skilled in the art that the location management

10 system and method of the wireless overlay network provided by the invention could be modified in various ways without departing from the spirit of the invention. Therefore, the scope the invention claimed should be determined by the content of appended claims.

Claims

CLAIMS:

1. A location management system of a wireless overlay network for managing location information of a mobile station in the wireless overlay network, comprising: a first wireless network including: a home location register (HLR) for storing the location information of the first wireless network and the location information of a second wireless network; a Convergence Point connected with said home location register; a second wireless network connected with the first wireless network via said Convergence Point; wherein said first wireless network and said second wireless network can access the mobile station based on the location information of the first wireless network and the location information of the second wireless network , respectively.

2. The location management system of a wireless overlay network according to claim 1, wherein the first wireless network is General Packet Radio Service (GPRS) network.

3. The location management system of a wireless overlay network according to claim 2, wherein the second wireless network is Wireless Local Area Network (WLAN).

4. The location management system of a wireless overlay network according to claim 2, wherein said Convergence Point is Gateway GPRS Support Node (GGSN).

5. The location management system of a wireless overlay network according to claim 2, wherein said Convergence Point is Service GPRS Support Node (SGSN).

6. The location management system of a wireless overlay network according to claim 2, wherein said Convergence Point is Mobile Switch Center (MSC).

7. A method for updating location information of a wireless overlay network, the method comprising the steps of: registering a mobile station in a first wireless network to obtain the location information of the first wireless network and storing it in home location register of the first wireless network; registering the mobile station in a second wireless network to obtain the location information of the second wireless network; said mobile station sending said location information of the second wireless network and storing it in said home location register.

8. The method for updating location information of a wireless overlay network according to claim 7, wherein the first wireless network is GPRS network.

9. The method for updating location information of a wireless overlay network according to claim 8, wherein the second wireless network is WLAN.

10. The method for updating location information of a wireless overlay network according to claim 9, wherein the mobile station sends said location information of the second wireless network via the GPRS network.

11. The method for updating location information of a wireless overlay network according to claim 9, wherein the mobile station sends said location information of the second wireless network to the Convergence Point via WLAN, and upon receiving the updated location information, the Convergence Point updates the repository and informs the HLR of the location information of the second wireless network.

12. The method for updating location information of a wireless overlay network according to claim 9, further comprising the steps of: if the Convergence Point loses all or part of the location information of the mobile station, when a call or packet whose destination is the mobile station arriving, the Convergence Point sending a query request to the HLR, and upon receiving the query request, the HLR sending the latest location information of the mobile station to the Convergence Point.

13. A communication method for a wireless overlay network, comprising the steps of: registering a mobile station in a GPRS network to obtain location information of a first wireless network and storing it in HLR; registering the mobile station in a WLAN to obtain location information of a second wireless network; sending the location information of the second wireless network to the HLR.

14. A mobile station, comprising:

A first wireless network module, which can be registered in a first wireless network to obtain the location information of the first wireless network; A second wireless network module, which can be registered in a second wireless network to obtain the location information of the second wireless network; wherein said mobile station sends said location information of the second wireless network and stores it in a home location register of the first wireless network.

15. The mobile station according to claim 14, wherein the first wireless network module is a GPRS network module.

16. The mobile station according to claim 15, wherein the second wireless network module is a WLAN module.

17. The mobile station according to claim 14, wherein the mobile station sends said location information of the second wireless network via the first wireless network module.

18. The mobile station according to claim 14, wherein the mobile station sends said location information of the second wireless network to the Convergence Point of the first wireless network via the second wireless network module, and upon receiving the location information of the second wireless network, the Convergence Point updates the repository and transmits it to the home location register.