HK1106041B - Internetworking between a first network and a second network - Google Patents

Description

Internetworking between a first network and a second network

Cross Reference to Related Applications

This application claims priority to U.S. provisional patent application 60/455,909 filed on 18/3/2003.

Technical Field

The present invention relates generally to wireless communication systems, and more particularly to such systems that allow internetworking between a first network and a second network.

Background

Code Division Multiple Access (CDMA) is a digital wireless technology that inherently has relatively large bandwidth capacity, i.e., it inherently allows more telephone call services per frequency band than other wireless communication technologies. Also, the spread spectrum principles of CDMA inherently provide secure communications. U.S. patent No. 4,901,307, which is incorporated herein by reference, discloses details of a CDMA system that can be used to transmit voice calls and non-voice computer data.

Despite the advantages of CDMA, there are other wireless systems that employ other principles. For example, GSM is widely used throughout the world, using time division multiple access.

Whether using CDMA principles or other wireless principles, a wireless communication system may be considered to have two main components, namely a radio access radio network (RAN) and a core infrastructure, which communicates with the RAN and external systems, such as the Public Switched Telephone Network (PSTN), the internet (particularly although not exclusively for data calls), etc. The core infrastructure associated with various wireless technologies is very expensive, both in terms of hardware and in terms of developing communication protocols that are intended to support personalization, general system-specific call handoffs, subscription and service validation and call monitoring, and billing. Therefore, the communication protocols of one wireless system (GSM protocol in the case of GSM, and CDMA protocols such as CDMA2000-1x, IS-41 in the case of CDMA) may not be compatible with the protocols of other systems without a very costly modification to the core infrastructure in one system or the other.

It is highly desirable to establish internetworking between CDMA networks and GSM networks so that CDMA based RANs can be utilized, with its service advantages, and GSM based core infrastructure can be utilized, since GSM is abundant throughout the world.

Thus, a dual-mode mobile station has the advantage of being able to connect with the GSM core infrastructure when in, for example, europe, and using the CDMA infrastructure when in, for example, the united states.

Disclosure of Invention

In one aspect of the invention, a General Global Gateway (GGG) configured to support communication between a first network and a second network to enable a Mobile Station (MS) subscribed in the first network to communicate with the second network includes a database configured to store an identity of the mobile station and logic configured to execute program logic to obtain authentication information from the first network based on the identity of the mobile station by executing the program logic.

In another aspect of the invention, a General Global Gateway (GGG) includes means for storing an identity of the mobile station, and means for executing program logic to obtain authentication information from the first network based on the identity of the mobile station.

In still another aspect of the present invention, a method of wireless communication between a first network and a second network, which enables a Mobile Station (MS) subscribed in the first network to communicate with the second network, comprises: storing an identity of the mobile station, obtaining information from the first network based on the identity of the mobile station, storing the authentication information from the first network in a General Global Gateway (GGG), and authenticating the mobile station using the stored authentication information from the first network.

In yet another aspect of the invention, a computer readable medium embodying a program of instructions executable by a computer program to implement a method of wireless communication between a first network and a second network, the method enabling a Mobile Station (MS) subscribed in the first network to communicate using the second network, the method comprising: storing an identity of the mobile station, obtaining authentication information from the first network based on the identity of the mobile station, storing the authentication information from the first network in a General Global Gateway (GGG), and authenticating the mobile station using the stored authentication information from the first network.

It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

Drawings

FIG. 1 shows a block diagram of a wireless communication system including a CDMA network, a GSM network, a General Global Gateway (GGG), and a mobile station; and

fig. 2a and 2b show a flow diagram for authenticating and accessing a first network when roaming in a second network, according to an embodiment.

Detailed Description

The present invention relates generally to wireless communication systems, and more particularly to a system that allows internetworking between a first network and a second network. Fig. 1 shows a first network, a CDMA network 12, internetworking with a second network, a GSM network 14, according to an embodiment.

Fig. 1 shows a block diagram of a wireless communication system 10 including a CDMA network 12, a GSM network 14, a General Global Gateway (GGG)16, and mobile stations 18, 20, 22, 24. The GSM mobile station 20 includes a Subscriber Identity Module (SIM) 19. CDMA mobile station 24 includes a SIM 28. The SIMs 19, 28 are removably connected with the mobile stations 20, 24, respectively, in accordance with principles known in the art. In an embodiment relating to a GSM network, the GGG is referred to as a GSM global gateway.

The GGG16 implements internetworking between the CDMA network 12 and the GSM network 14. The GGG includes a transceiver (not shown) that enables it to send and receive messages to and from the CDMA network 12 and GSM network 14.

In one embodiment, the CDMA network is an ANSI-41 network. As will be apparent to those skilled in the art, the CDMA network 12 may be a variety of CDMA networks including, but not limited to, CDMA2000-1x and CDMA2000-1 xEV-DO.

It will also be apparent to those skilled in the art that the GSM network 14 may be various GSM networks or successor networks including, but not limited to, General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), and wideband code division multiple Access (W-CDMA).

It will also be clear to those skilled in the art that the networks 12, 14 are not limited to GSM and CDMA. For example, the networks 12, 14 may be 802.11, WiMax, or Internet Protocol (IP) networks. The CDMA network 12 and the GSM network 14 are specified in fig. 1 for illustrative purposes. In one embodiment, if one of the two networks 12, 14 is a GSM network, the GGG may be considered an acronym for GSM global gateway.

The GSM network 14 includes a GSM core 30 and a GSM radio access network 32. The GSM core 30 includes a GSM home location register (GSM HLR)34, a GSM authentication center (GSM AUC)36, a GSM short message center (GSM SMSC)38, and a GSM gateway mobile switching center (GSM GMSC) 40. The CDMA network 12 includes a CDMA home location register (CDMA HLR)42, a CDMA authentication center (CDMA AUC)44, a CDMA msc46, and an associated CDMA radio access network (CDMA RAN) 48.

For GSM mobile stations with subscriptions in the CDMA core 20, the GGG16 functions as a Visitor Location Register (VLR)50 to the GSM network 14. For CDMA mobile stations 24 with subscriptions in the GSM core 30, the GGG16 functions as a Visitor Location Register (VLR)52 to the CDMA network 12.

The mobile stations 18, 20, 22, 24 need not have a subscription in both core infrastructures 12, 14, and may have a subscription in only one of the core infrastructures 12, 14.

The GGG16 acts as a Short Message Service Center (SMSC)54 for both GSM mobile stations with subscriptions in the CDMA core 20 and CDMA mobile stations with subscriptions in the GSM core 30. It will be apparent to those skilled in the art that the GGG16 may include or communicate with the SMSC 54.

In one embodiment, the GGG16 includes a service center that sends and receives IP messages. It will be apparent to those skilled in the art that the GGG16 may comprise any service center known in the art to send and receive messages in the protocol of the service center. In one embodiment, messages may be sent and received by the GGG16, where messaging services provided by the first network may not be provided by the second network.

The mobile stations 18, 20 support the GSM signaling protocol, GSM authentication procedures, and GSM short message service. Similarly, the mobile stations 22, 24 support CDMA signaling protocols, CDMA authentication procedures, and CDMA short message service.

During registration with a CDMA mobile station having a subscription in the GSM core 30, the GGG acts as an authentication controller in the CDMA network, but authenticates the mobile station 24 using the GSM authentication mechanism. Similarly, during registration of a GSM mobile station with a subscription in the CDMA core 20, the GGG acts as an authentication controller in the GSM network, but authenticates the mobile station 20 using a CDMA authentication mechanism.

The GGG16 acts as a message center via the short message service center 54. In a CDMA network, SMS messages are sent to and from the mobile station 24 using the GSM SMS mechanism. Similarly, in a GSM network, SMS messages are sent to and from the mobile station 20 using a CDMA SMS mechanism.

The GGG16 receives location messages from mobile stations 20, 24. The GGG uses the identifier in the location message to obtain authentication information to know which HLR/AUC it needs to query.

Incoming calls to a registered GSM subscriber 24 arrive at a GSM gateway msc (GSM gmsc)40 in the subscriber's home GSM network 14. The GMSC 40 interrogates the GSM LR 50 to determine the location of the subscriber 24 in the CDMA network 12. The location of the GSM subscriber 24 is in the GGG16 from the perspective of the GSM LR 50, which is taken as GSM vltlr. When the GSM LR 50 requests delivery information from the GGG16, the GGG16 requests delivery information from the serving CDMA LR 52 so that the call is delivered to the CDMA MSC 46.

Similarly, an incoming call to a registered CDMA subscriber 20 arrives at the CDMA MSC46 in the subscriber's home CDMA network 12. The CDMA MSC46 interrogates the CDMA LR 52 to determine the location of the subscriber 20 in the GSM network 14 the location of the CDMA subscriber 20 from the perspective of the CDMA LR 52 is in the GGG16, which acts as a CDMAVLR. When the CDMA LR 52 requests delivery information from the GGG16, the GGG16 requests delivery information from the serving GSM LR 50 so that the call is delivered to the GSM GMSC 40.

The CDMA based mobile stations 22, 24 communicate with a CDMA Mobile Switching Center (MSC)46 using a CDMA Radio Access Network (RAN)48 in accordance with CDMA principles known in the art. In one embodiment, the CDMA MSC46 IS an IS-41 MSC. Similarly, the GSM-based mobile stations 18, 20 communicate with a GSM mobile switching center (GSM GMSC)40 using a GSM RAN 32, in accordance with GSM principles known in the art.

The CDMA RAN 48 includes base stations and base station controllers in accordance with CDMA principles known in the art. In one embodiment, the CDMA RAN 24 shown in fig. 1 uses CDMA2000, and more specifically, uses CDMA 20001 x, CDMA 20003 x, or CDMA2000 High Data Rate (HDR) principles.

The GSM RAN 32 includes base stations and base station controllers in accordance with GSM principles known in the art. In one embodiment, the GSM RAN 32 uses GSM, GPRS, EDGE, UMTS, or W-CDMA principles.

The CDMA core infrastructure, including the CDMA MSC46 and CDMA RAN 48, may include or have access to a CDMA authentication center (CDMA AUC)44 and a CDMA home location register (CDMA HLR)42,

to authenticate the subscriber mobile station 22 and to collect billing and accounting information required by the particular CDMA core infrastructure.

Similarly, the GSM core 30 may include or have access to a GSM authentication center (GSM AUC)36 and GSM home location register (GSM hlr)34 to authenticate the subscriber mobile station 18 and to collect billing and accounting information required by the particular GSM core infrastructure, in accordance with GSM principles known in the art.

The CDMA MSC46 communicates with the GSM network 14 using the GGG 16. The GSM network 14 may include or have access to a GSM authentication center 36 and GSM Home Location Register (HLR)34 to authenticate subscriber mobile stations 24 and collect billing and accounting information needed for that particular GSM core 30, in accordance with GSM principles known in the art.

Similarly, the GSM GMSC 40 communicates with the CDMA network 12 using the GGG 16. The CDMA network 12 may include or have access to a CDMA authentication center 44 and a CDMA Home Location Register (HLR)42 to authenticate subscriber mobile stations 20 and collect billing and accounting information needed for the particular CDMA network 12 in accordance with CDMA principles known in the art.

The GSM core 30 and the CDMA core infrastructure both communicate with networks such as the Public Switched Telephone Network (PSTN) and/or the Internet Protocol (IP) network.

For CDMA mobile stations 24 with subscriptions in the GSM core 30, the GGG16 functions as a VLR 50 to the GSM network 14. The GGG meets the GSM protocol requirements for VLR 50. Except that the GGG16 sends incoming calls to the CDMA network 12, the GGG interacts with GSM core network elements, such as GSM HLR 34 and GSM SMSC 38, in accordance with GSM specifications. The GSM LR 50 also performs location updates with the GSM network 14 when the mobile station registers with the CDMA network 12. In this sense, the GGG acts as a VLR to the entire CDMA network 12.

For GSM mobile stations 20 with subscriptions in CDMA network 12, the GGG16 functions as a VLR 52 to the CDMA network 14. The GGG satisfies CDMA protocol requirements for VLR 52. The GGG interacts with CDMA core network elements, such as CDMA HLR42 and CDMA MSC46, in accordance with CDMA specifications, except that the GGG16 routes incoming calls to the CDMA network 12. The CDMA LR 52 also performs location updates with the CDMA network 12 when the mobile station registers with the GSM network 14. In this sense, the GGG acts as a VLR to the entire GSM network 14.

When a mobile station in the CDMA network 12 is called from the GSM network 14, the call is routed to the CDMA LR 52 in the GGG16 via standard specifications. The GGG16 sends the call to the CDMA network 12. The CDMA network 12 ultimately routes the call to the CDMA MSC46 serving the mobile station. Similarly, if an SMS is sent from the GSM network 14 to the CDMA network 12, the GGG16 sends the message to a message center (not shown) in the CDMA network 12.

When a mobile station in the GSM network 14 is called from the CDMA network 12, the call is routed to the GSM LR 50 in the GGG16 via standard specifications. The GGG16 sends the call to the GSM network 14. The GSM network 14 ultimately routes the call to the GSM GMSC 40 serving the mobile station. Similarly, if an SMS is sent from the CDMA network 12 to the GSM network 14, the GGG16 sends the message to a GSM SMSC 38 in the GSM network 14.

When a mobile station registers with the CDMA network 12, the CDMA network 12 sends a location update indication to the GSM network 14. The GSM LR 50 then performs location updates using the GSM core network 14 in accordance with standard specifications.

When a mobile station registers with the GSM network 14, the GSM network 14 sends a location update indication to the CDMA network 12. The CDMA LR 52 then performs location updates using the CDMA core network 12 in accordance with standard specifications.

For CDMA mobile stations 24 with subscriptions in the GSM core 30, the GGG16 acts as an HLR 52 in the CDMA network 12. The CDMA LR 52 needs to meet HLR protocol requirements for GSM to CDMA roaming. One important piece of information maintained by the HLR is the address of the CDMA MSC46 serving the mobile station 24. When the gsm LR 50 in the GGG16 sends a call to the CDMA side 12, the CDMA LR 52 will again send it to the serving MSC 46.

For a GSM mobile station 20 with a subscription in the CDMA network 12, the GGG16 acts as an HLR 50 in the GSM network 14. The GSM LR 50 needs to meet HLR protocol requirements for CDMA to GSM roaming. One important piece of information maintained by the HLR is the address of the GSM GMSC 40 serving the mobile station 20. When the CDMALR 52 in the GGG16 sends a call to the GSM side 14, the GSM LR 50 will again send it to the serving MSC 40.

The GGG is the GSM user 24 as an authentication controller (AUC) in the CDMA network. The AUC 44 in the CDMA network 12 is responsible for authenticating mobile stations and granting/denying access to network resources. The AUC function in the GGG does not require a-key provisioning at the a-bond of the GGG or the MS. Instead, the GGG authenticates the mobile station 24 via GSM signaling using the GSM authentication credentials and the GSM authentication method. The GGG responds to a valid message that may be received by the CDMA AUC 44.

The GGG is the CDMA user 20 acting as an authentication controller (AUC) in the GSM network. The AUC 36 in the CDMA network 14 is responsible for authenticating mobile stations and granting/denying access to network resources. The AUC functions in the GGG do not require a donation at the a-bond of the GGG or the MS. Instead, the GGG authenticates the mobile station 20 via CDMA signaling using the CDMA authentication credentials and the CDMA authentication method. The GGG responds to a valid message that may be received by the GSM AUC 36.

The GGG16 acts as a Message Center (MC) in the CDMA network 12 and uses the GSM SMS mechanism to send SMS messages between the CDMA mobile station 24 and the GSM GMSC 40.

Similarly, the GGG16 acts as a Message Center (MC) in the GSM network 14 and uses CDMA SMS mechanisms to send SMS messages between the GSM mobile station 20 and the CDMA MSC 46.

The CDMA MS 24 is required to have a valid identity in the CDMA network. If this identity is different from a GSM International Mobile Subscriber Identity (IMSI) (i.e., if the CDMA network does not use a true IMSI), the GGG provides a mapping between the CDMA identity and the GSM IMSI. It will be apparent to those skilled in the art that the mobile station 24 may be uniquely identified using any technique/method known in the art.

The GSM MS 20 is required to have a valid identity in the GSM network. In one embodiment, this identity is the GSM IMSI (i.e., if the CDMA network does not use the true IMSI). The GGG provides a mapping between the GSM identity and the CDMA identity if the identity in the GSM network is different from the identity in the CDMA network. It will be apparent to those skilled in the art that the mobile station 20 may be uniquely identified using any technique/method known in the art.

In one non-limiting embodiment, the mobile stations 18, 20 are mobile telephones manufactured by Kyocera, samsung, or other manufacturers that use GSM principles and the GSM over-the-air (OTA) communication air interface. In one non-limiting embodiment, the mobile stations 22, 24 are mobile telephones manufactured by Kyocera, samsung, or other manufacturers that use CDMA principles and a CDMA over-the-air (OTA) communication air interface. However, the invention is also applicable to other mobile stations, such as laptops, wireless handsets or telephones, data transceivers or pagers, and position location receivers. The mobile station may be hand-held or portable, or may be carried on a vehicle (including cars, trucks, boats, planes, trains), as desired. However, while wireless communication devices are generally considered to be mobile, it is to be understood that in some implementations the present invention may also be applied to "fixed" units. Also, the present invention is applicable to data modules or modems used to transfer voice and/or data information, including digitized video information, and may communicate with other devices using wired or wireless links. Further, the instructions may be utilized to cause the modem or module to operate in a predetermined coordinated or associated manner to transmit information over a plurality of communication channels. In some communication systems, a wireless communication device is also sometimes referred to as a user terminal, mobile station, mobile unit, subscriber unit, mobile radio or radiotelephone, wireless unit, or simply a "user" or "mobile.

Fig. 2a and 2b show a flow chart for authenticating and accessing a first network while roaming in a second network, according to an embodiment. In step 202, mobile station 24(MS) roams into a second network area and control flows to step 204. In step 204, the mobile station initiates registration system access (registration system access) and control passes to step 206. In step 206, the mobile station sends a registration message to the MSC46 of the second network via the RAN 48 of the second network, and the control flow proceeds to step 208.

The registration system access is a message via the RAN 48 to the MSC46 that includes the identity of the mobile station. In one embodiment, the identity of the mobile station may be provided by the SIM 28. In one embodiment, the identity of the mobile station 24 is an IMSI. In one embodiment, the identification of the mobile station is a Mobile Identification Number (MIN).

In step 208, the MSC46 determines the network subscription, i.e., whether the mobile station is a subscriber of the second network or the first network, based on the mobile station identification. In one embodiment, the identity of the mobile station is an IMSI, and the MSC46 may make this determination because the IMSI includes, among other information, a code that indicates the country and network in which the mobile station has a subscription. The flow of control proceeds to step 210.

In step 210, the MSC46 of the second network determines the subscription of the mobile station from the mobile station identity. If the mobile station 24 is a subscriber of the second network, the mobile station 22 is authenticated in step 212 using the HLR42 and AUC 44 of the second network using principles of the core infrastructure of the second network. If the mobile station 24 is a subscriber of the first network 14, the MSC46 of the second network sends the mobile station identification and location along with authentication parameters to the GGG in step 212. The flow of control proceeds to step 214.

In step 214, a check is made to determine if the GGG16 finds the identity of the mobile station in a GGG database (not shown) and if the authentication parameters meet GGG authentication criteria. If not, the GGG16 sends a message to the mobile station via the MSC46 and RAN 48 of the second network indicating that the mobile station is not authenticated in step 216. If the result of the check is true, the GGG16 sends the identity and location of the mobile station and authentication parameters to the core of the first network in step 218 and control flows to step 220.

The GGG includes a logic unit (not shown) to execute program logic. It will be apparent to one skilled in the art that the logic units may include a general purpose processor, a special purpose processor, and/or firmware.

In step 220, a check is made to determine if the core of the first network finds the identity of the mobile station in the core of the first network and if the authentication parameters meet the authentication criteria of the first network. If not, the core of the first network sends a message to the mobile station via the MSC46 and RAN 48 of the second network indicating that the mobile station is not authenticated in step 222. If the check is true, the core of the first network updates the location of the mobile station and sends an authentication message with authentication parameters to the GGG16 in step 224 and control flows to step 226.

In step 226, the GGG16 stores authentication parameters of the first network for subsequent access by the mobile station. Thus, it is not necessary to perform the entire authentication procedure on subsequent accesses, which means that access to the core of the first network is not required. The flow of control proceeds to step 228.

In step 228, the GGG16 sends the authentication message to the MSC46 of the second network, and the MSC46 sends the authentication message to the mobile station via the RAN 48 of the second network. The flow of control proceeds to step 230.

After a period of time, the mobile station re-accesses the first network in step 230 and control passes to step 232.

In step 232, a check is made to determine if the verification parameters continue to satisfy the GGG verification criteria. If not, the GGG16 sends a message to the mobile station via the MSC46 and RAN 48 of the second network in step 234. If the result of the check is true, then the mobile station accesses the first network in step 236. Control proceeds to step 230 for the next time the mobile station accesses the first network.

Method steps may be interchanged without departing from the scope of the invention.

Once authenticated, the mobile station 24 may communicate directly with the first network 14 via, for example, an IP network. It will be clear to those skilled in the art that when the mobile station is not authenticated, the mobile station may attempt re-authentication, as applicable.

While the particular internetworking between CDMA networks and GSM networks shown and described in detail herein is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is presently contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more". No element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims.

Method steps may be interchanged without departing from the scope of the invention.

Claims (20)

1. A ggg configured to support communication between a first network and a second network to enable a mobile station subscribed in the first network to communicate using the second network, comprising:

a database configured to store an identification of the mobile station;

a checking unit configured to check to determine whether the ggg finds the identity of the mobile station in the database when the mobile station roams into the second network and initiates registration and receives the identity from the mobile station; and the number of the first and second groups,

logic configured to execute program logic to obtain authentication information from the first network based on the identity of the mobile station.

2. The ggg of claim 1, further comprising a location register configured to store a location of the mobile station such that a call incoming to the mobile station from the first network may be sent to the mobile station through the ggg.

3. The ggg of claim 1, wherein the logic unit is further configured to determine whether authentication parameters from the mobile station satisfy ggg authentication criteria.

4. The ggg of claim 1, further comprising a service center configured to send and receive messages to and from the second network according to a message format of the service center.

5. The ggg of claim 2, further comprising a second location register configured to store a location of the mobile station such that calls outgoing from the mobile station to the first network may be routed from the mobile station through the ggg.

6. The ggg of claim 4, wherein the service center is configured to send and receive internet protocol messages to and from the second network.

7. The ggg of claim 4, wherein the service center is a short message service center configured to send messages to and receive messages from the second network.

8. The ggg of claim 4, wherein the message conveys a service that is provided by the first network and not provided by the second network.

9. The ggg of claim 7, wherein the short message service center is configured to send and receive messages to verify subscriptions in the network.

10. A ggg configured to support communication between a first network and a second network to enable a mobile station subscribed in the first network to communicate using the second network, comprising:

means for storing an identification of the mobile station;

means for checking to determine if the ggg finds the identity of the mobile station in the means for storing the identity of the mobile station when the mobile station roams into the second network and initiates registration and receives the identity from the mobile station; and the number of the first and second groups,

means for executing program logic to obtain authentication information from the first network based on the identity of the mobile station.

11. The ggg of claim 10, further comprising means for storing a location of the mobile station such that a call incoming to the mobile station from the first network may be routed to the mobile station through the ggg.

12. The ggg of claim 10, wherein the means for executing program logic is configured to determine whether authentication parameters from the mobile station satisfy ggg authentication criteria.

13. The ggg of claim 11, further comprising means for sending and receiving short message service messages to and from the second network.

14. The ggg of claim 10, further comprising means for storing a location of the mobile station such that outgoing calls from the mobile station to the first network may be routed from the mobile station through the ggg.

15. A method of wireless communication between a first network and a second network that enables a mobile station subscribed in the first network to communicate with the second network, comprising:

storing an identification of the mobile station;

when the mobile station roams into the second network and initiates registration and receives an identity from the mobile station, checking by the second network to determine if the identity of the mobile station is stored;

obtaining authentication information from the first network based on the identity of the mobile station;

storing said authentication information from said first network in a general purpose global gateway; and the number of the first and second electrodes,

authenticating the mobile station using the stored authentication information from the first network.

16. The method of claim 15, further comprising storing a location of the mobile station such that a call incoming to the mobile station from the first network can be routed to the mobile station through the ggg.

17. The method of claim 15, further comprising determining whether authentication parameters from the mobile station satisfy ggg authentication criteria.

18. The method of claim 15, further comprising communicating directly from the mobile station to the first network after the mobile station is authenticated in the first network.

19. The method of claim 16, further comprising being configured to send and receive short message service messages to and from the second network.

20. The method of claim 16, further comprising storing a location of the mobile station such that calls outgoing from the mobile station to the first network may be routed from the mobile station through the ggg.