Patent Application
20050021634
The present disclosure relates generally to voice and data communications, and more particularly, to a system and method for providing services to a wireless mobile terminal operating in a hybrid wireless network.
A typical wireless network is composed of two sub-networks: a Radio Access Network (RAN) which handles radio related issues such as assigning radio resources to a mobile terminal (or “mobile” in short) upon request for services, and a Core Network (CN) which links the mobile user to wireline networks. Current specifications of wireless networks require that the RAN and CN have the same wireless technology in order to provide wireless services. These networks may be referred to as “homogeneous networks.” For instance, a GSM mobile will only operate in a wireless network which its RAN and CN are both GSM wireless technology based.
The GSM RAN 102 includes a GSM Mobile Station (MS) 106 that communicates to a GSM Base Station System (BSS) 108 through a GSM radio channel 110. The GSM BSS 108 includes a GSM Base Transceiver Station (BTS) 110 and GSM Base Station Controller (BSC) 112.
The GSM Core Network (CN) 104 includes a GSM Mobile Switching Center (MSC) 120 that is connected to the GSM BSC 112 as well as a GSM Gateway MSC (GMSC) 122 by using SS7 ISUP communications 124. The GSM GMSC 122 is also connected to the Public Switched Telephone Network (PSTN) 126 by using SS7 ISUP communications 124. In this figure, a telephone 128 is shown to be connected to the PSTN as an illustration of a calling/called party. In addition, a Serving General Packet Radio Service Node (GPRS) (SGSN) 130 is shown to also be connected to the GSM BSC 112. Moreover, a GSM Short Message Service Center (SMS-C) 132, a GSM Home Location Register (HLR) 134 and a GSM Authentication Center (AuC) 136 are all shown to be connected the GSM MSC 120 and the SGSN 130. Further, a GSM Service Control Point (SCP) 138 connects a GSM Billing System 140 to the GSM MSC 120 and the GSM HLR 134. The connection from the GSM Billing System 140 and the GSM MSC 120 utilizes IP. Additionally, a Packet Data Network (PDN) 142 is shown connected to the GSM CN 104 through a Gateway GPRS Node (GGSN) 144 utilizing IP communications.
A disadvantage of this configuration is that, given many wireless technologies that exist today and considering new ones being defined for the future, this is a serious limitation in the wireless service provision to deal with a situation in which a mobile compatible with one wireless technology moves into a wireless network of different technology. This prevents the mobile from getting services and limits the mobile's geographical service area to networks that support a specific wireless technology. The same limitation applies to wireless networks that are CDMA wireless technology based.
The CDMA2000 RAN 201 includes a CDMA2000 MS 202 connected to a CDMA2000 BSS 204 through a CDMA2000 BTS 206. The CDMA2000 BTS 206 is in turn connected to a CDMA2000 BSC 208, which connects to a Packet Control Function (PCF) 210.
The CDMA2000 CN 212 connects to the CDMA2000 RAN 201 by the CDMA2000 BSC 208 connecting to the CDMA200 MSC 214. The CDMA2000 MSC 214 is connected to an IS-41 SMS-C 216, an IS-41 HLR 218, an IS-41 AuC 220 and an IS-41 SCP 222. The IS-41 SCP 222 in turn is also connected to the IS-41 HLR 218 and a Store and Forward Service 224, which in turn is connected to an IS-41 Billing System 226. In addition, a Packet Data Serving Node (PDSN) 228 is connected to the PCF 210 of the CDMA2000 RAN 200 and a PDN 230. Moreover, the CDMA2000 MSC 214 connects the CDMA2000 CN 212 to the PSTN 232 and a phone 234.
A hybrid wireless network is a wireless network composed of a RAN and a CN of different technologies linked.
For example, in most wireless networks, wireless services are granted to a mobile after it is authenticated. This process is known as the authentication of a mobile. Different wireless technologies use different procedures and algorithms to perform such an authentication process. For instance, a CDMA mobile operating in a CDMA network generates authentication parameters which are quite different from those generated by a GSM mobile operating in a GSM network. There are currently no known solutions to provide authentication of a mobile operating in a hybrid wireless network.
Another problem is exchanging short message service (SMS) between different networks. Turning back to
What is needed, therefore, is a method and system for providing a solution to pass information and parameters to and from a mobile in a hybrid wireless network.
Embodiments of a method and system are disclosed to pass information or message contents between a mobile terminal and various networks entities in a hybrid wireless network. One embodiment includes a hybrid wireless network having at least one radio access network (RAN) based on a first technology and a core network (CN) based on a second technology. The hybrid network uses a special Mobile Switching Center to be a “double agent” passing information between the mobile terminal and entities in the CN. In the context of messaging, the message contents may be encoded, packaged, and decoded appropriately.
In one example embodiment, a method and system is disclosed for providing authentication of a mobile terminal in a hybrid wireless network, the hybrid wireless network having at least one radio access network (RAN) based on a first technology and a core network (CN) based on a second technology. When the mobile terminal from the RAN requests a registration, the CN passes predetermined parameters for the authentication to the mobile terminal through a hybrid mobile switching center (HMSC) using messages conforming to the first technology. The passed parameters conforms to the second technology. With these parameters, an authentication process is invoked by the mobile terminal. The result of the authentication is sent out to the HMSC of the CN. The HMSC is capable of communicating to both the mobile terminal and the CN with messages conforming to either the first or second technologies.
In another example embodiment, a method and system is provided to perform mobile authentication in a hybrid wireless network composed of a CDMA RAN and a GSM CN. Effectively, the present disclosure provides a method and procedure to send GSM information from the GSM CN to the mobile in the CDMA RAN, and from the mobile in the CDMA RAN back to the GSM CN through a Hybrid Mobile Switching Center (HMSC). For example, IS-41 DTAP messages are used to transfer GSM information from the HMSC to the mobile and from the mobile to the HMSC. Furthermore, CDMA messages parameters are mapped into GSM messages parameters.
In yet another example embodiment, a method and system is disclosed for transmitting message contents in a hybrid wireless network, the hybrid wireless network having at least one radio access network (RAN) based on a first technology and a core network (CN) based on a second technology, and the RAN and CN having different encoding and decoding schemes for the message contents. The predetermined message contents are sent in a message of a first type from a network entity in the CN to a Hybrid Mobile Switching Center (HMSC) using a first encoding scheme. The HMSC extracts the encoded message contents, and packages the extracted message content in a second message of a second type readable by a mobile terminal in the RAN. The mobile terminal extracts the message contents from the second message, and decodes the message contents encoded by the first encoding scheme. The HMSC is capable of communicating to both the mobile terminal and the CN with messages conforming to either the first or second technologies and wherein the mobile terminal is a dual mode terminal operable with either the first or the second technologies.
Similarly, for communications initiated by the mobile terminal, an embodiment of method and system is disclosed for transmitting message contents in a hybrid wireless network, the hybrid wireless network having at least one radio access network (RAN) based on a first technology and a core network (CN) based on a second technology, the RAN and CN having different encoding and decoding schemes for the message contents. When the message contents are sent in a message of a first type from a mobile terminal in the RAN to a Hybrid Mobile Switching Center (HMSC) in the CN using a first encoding scheme, the HMSC extracts the encoded message contents, packages the extracted message content in a second message of a second type readable by a predetermined network entity in the CN. The message contents from the second message are extracted by the network entity, and decoded accordingly using the first encoding scheme, wherein the HMSC is capable of communicating to both the mobile terminal and the CN with messages conforming to either the first or second technologies and wherein the mobile terminal is a dual mode terminal operable with either the first or the second technologies.
Henceforth, the present disclosure presents a solution to deploy a new radio technology into wireless networks without introducing any change to the core network. This creates a huge advantage for network operators that looking to expand their wireless service coverage of a new radio technology. The present disclosure needs very low cost and short deployment time considering that the core network does not have to be changed whatsoever. By deploying a new radio technology over an existing core network of existing technologies, major advantages are achieved at the radio access network such as higher bit rates. Other advantages are higher network capacity and increase in spectrum efficiency on the radio which leads to the ability of supporting larger number of subscribers and introducing better quality of service to the mobile user end. This means providing larger service coverage area and higher revenues to network operators.
For the purposes of the present disclosure, various acronyms are used, and the definitions of which are listed below:
The present disclosure provides several examples below, and it is understood that the examples are not necessarily limitations to the present invention, but are used to describe embodiments of the method and system of the present invention. The general concept is to pass information or message contents between a mobile terminal and various networks entities in a hybrid wireless network. The hybrid network implements a special mobile switching center to be a “double agent” passing information between the mobile terminal and entities in the CN. In the context of messaging, the message contents may be encoded, packaged, and decoded appropriately.
The example network architecture shown in
Similarly, in the CDMA RAN 306, a CDMA 2000 mobile phone 320 communicates with a CDMA BTS 322 over a CDMA radio link 324. The CDMA BTS 322 typically communicates with a CDMA BSC 326 using a proprietary wired link 328. Typically, for voice communications, the CDMA BSC 326 communicates with the HMSC 308 over a link 330 using a variety of protocols, including A1, A2, A5, A8, and A9. The CDMA BSC 326 transfers data to a PCF 332 over a link 334 using A8 and A9 protocols. Thus, data is usually sent by the PCF 332 to the HMSC 308 over a link 336 using the A10 and A11 protocols.
If the core network is a GSM network, as in the illustrative network 300, the HMSC 308 communicates with the other GSM network components in much the same way a typical MSC would communicate with the GSM network components. For instance, the HMSC 308 may establish links with a GMSC 340, a SCP 342, an HLR 344, a AuC 346, a PDN 347, a GGSN 348, and/or a SMS-C 350. Similarly, the GMSC 340 may communicate with a PSTN 352 through a T1 link 354 using a SS7 ISUP protocol. The SCP 342 may establish a link 356 with a billing system 358, and the GGSN 348 may establish a link 360 with the PDN 347, where the links 356 and 360 uses an IP protocol. Thus, for each connection,
Thus, for calls established with the GSM mobile 310, the HMSC 308 acts like a GSM MSC 110 as depicted in
The HMSC 308 can support voice and packet data call services from mobiles in any type of RAN to any other type of network. For instance the mobile 310 in the GSM RAN 304 can make a call to another mobile (not shown) operating in the CDMA RAN 306, a telephone 362 connected to the PSTN 352, or an entity as part of the PDN 347 and other networks that are not illustrated nor discussed in this disclosure for reasons of simplicity and clarity. The HMSC 308 is shown in communication with two RANs of different technologies, however as would be clear to one skilled in the art, the present invention also applies in situations where the HMSC 308 is in communication with one or more RANs of same technology.
Wireless services are granted to a mobile phone after the mobile phone is “authenticated.” Different wireless technologies use different procedures and algorithms to perform such an authentication process. For instance, the GSM mobile phone 310 operating in the GSM RAN 304 generates authentication parameters which are different from those generated by the CDMA mobile phone 320 operating in the CDMA RAN 306. Thus, one aspect of the present invention solves this problem by providing for a method of authentication of a mobile terminal in a hybrid wireless network, the hybrid wireless network having at least one radio access network (RAN) based on a first technology (e.g. CDMA) and a core network (CN) based on a second technology (e.g., GSM). Generally, the method comprises: requesting a registration of the mobile terminal from the RAN; passing predetermined parameters for the authentication by the CN through a HMSC to the mobile terminal using messages conforming to the first technology, the parameters conforming to the second technology; invoking an authentication process by the mobile terminal using the passed parameters; and informing the HMSC of the CN for the authentication of the mobile terminal.
As is known in the art, a GSM authentication checks the validity of the subscriber's SIM card and then decides whether the mobile station should be allowed on a particular network. In a typical GSM network, the authentication process begins when a BSS/MSC/VLR sends the RAND and a GSM Cipering Key sequence (“Kc”), to the mobile unit. The mobile unit uses the RAND and its own Ki to generate a SRES, which is then sent back to the BSS/MSC/VLR. The BSS/MSC/VLR compares the value of SRES received from the AuC with the value of SRES it has received from the mobile station. If the two values of SRES match, authentication is successful and the subscriber joins the network.
When the BSS 329 receives the registration message 402, the BSS 329 sends a DTAP: Location Updating Request 404 to the HMSC 308. In response, the HMSC 308 transforms the DTAP: Location Updating Request 404 to a security related information request 406, which requests security related information from the HLR/AuC corresponding to the mobile station. Upon receiving the expected authentication information, the AuC 346 retrieves a Subscriber authentication key (“Ki”) from its database. The AuC 346 and the HLR 344 generate a random value (“RAND”), and using the Ki, computes a Signed RESponses (“SRES”). In step 408, the HLR/AuC sends an Authentication Vector Response 408 to the HMSC 308. The parameters contained in the response 408 include, a RAND, SRES, and a Cipering Key sequence (“Kc”). The HMSC 308 stores these parameters.
In this embodiment, the RAND and the Kc are passed back to the mobile unit 320 so that the mobile unit can generate its own SRES. The parameters are to be transparent to all entities in the CDMA RAN 306 except the mobile unit 320. In other words, none of the entities in the RAN 306 are supposed to read or act upon the parameters, except for simply forwarding them to the next entity until the destination is reached.
In the present disclosure, a DTAP message is used because all DTAP messages are transparent to the entities in the RAN between the mobile and the HMSC. In the illustrative example, the CDMA DTAP message used is an “Authentication_Request.” However, according the CDMA standard, this message cannot hold more than 3 bytes of data for parameters. However, the RAND has a length of 16 bytes and Kc has a length of ½ byte. Consequently, a total of 16 and ½ bytes of space is required in a CDMA message to pass these parameters to the mobile unit 320. Therefore, 6 subsequent messages are used to transfer all the GSM parameters to the mobile. Thus, a DTAP: Authentication_Request 410a message is sent from the HMSC 308 to the BSS 329. In response the BSS 329 passes these parameters to the mobile unit 320 in the form of an Authentication Challenge 412f. This process is repeated six times until the DTAP: Authentication_Request 410f message is received by the BSS 329, which in response sends an Authentication Challenge 412f to the mobile unit. When the mobile unit 320 receives the message 412a, it reassembles the segmented GSM parameters. Given that the mobile is a dual mode one, it uses RAND and Kc as input parameters to its GSM authentication algorithm which will generate its own GSM “Authentication Response parameter” or SRES. As explained previously, this parameter is normally uploaded back to the typical GSM network where it is compared with an SRES value generated by the network using RAND and Kc, and thereby confirming that the mobile is authentic. Thus, the SRES value generated by the mobile unit 320 is sent back to the Hybrid MSC 308 for verification. The SRES parameter has a total length of 4 bytes. The Authentication Challenge Response message, which may be used to pass the SRES parameter to the HMSC has 2 free bytes. Thus, the SRES parameter may be split over an Authentication Challenge Response message 414a and a Authentication Challenge Response message 414b, which are sent by the mobile unit 320 to the BSS 329. In response, the BSS 329 forwards the parameter to the HMSC 308 over two DTAP: Authentication Response messages 416a and 416b. When the HMSC 308 receives the messages 416a and 416b, it reassembles the segmented SRES and compares this value to the SRES value it generated to authenticate the mobile unit 320. If the values are the same, the HMSC 308 authenticates the mobile unit 320.
After authenticating the mobile, the HMSC 308 replies with a CDMA “Location Update accept” message 418 which is sent to the BSS 329. The BSS 329 translates the message 418 into a “Registration Accept” message 420 and sends message 420 to the mobile unit 320. The mobile unit 320 now can have service and make calls.
The above disclosure provides many different embodiments, or examples, for implementing the disclosure. However, specific examples, and processes are described to help clarify the disclosure. These are, of course, merely examples and are not intended to limit the disclosure from that described in the claims. For instance, even if a sample registration message and procedure is used to describe the disclosure, the present disclosure still applies to any scenario or event that can occur in the wireless network and that causes the mobile or the network to initiate the authentication procedure. For instance, in the illustrative example, the DTAP message “Authentication Request” is used to transfer GSM information on the downlink. However, the present invention is equally applicable to any DTAP message currently specified or will be specified in the standards that can be used between the mobile and the HMSC. Similarly, the illustrative example uses an “Authentication Response” to transfer GSM information on the uplink. However, the present embodiment applies to any DTAP message currently specified or will be specified in the standards that can be used between the mobile and the HMSC. Similarly, even though certain message fields have been specifically discussed to carry the GSM information in the example embodiment, the present invention is equally applicable to any field or set of fields that are transparent to the network entities between the mobile and the HMSC.
Furthermore, the above-described method for implementing an authentication service is only used as an example. The method is equally applicable to message contents that are encoded using different coding schemes between the RAN and the CN. For instance, referring back to
Turning now to
An alternative embodiment is illustrated in
Although a general switching system is used to describe the HMSC, the present disclosure is applicable to any switching system that may include one or more network entities which have various call control systems. Such a switching system may serve one or more RANs of different technologies as well as RANs sharing the same technology. The switching system may also link the RANs of various technologies to a CN of a predetermined wireless technology. For instance, a soft switch technology can be used to implement the HMSC which may include two parts each implemented in an independent network entity. One of the two network entities may handle the control part of a call and the other network entity may handle the bearer part. Using soft switch technology to implement the HMSC, the present disclosure provides a maximum leverage of equipment investment since the network configuration becomes highly scalable.
Additionally, although a dual-mode mobile that can support voice and packet data is used to describe the disclosure, the present invention is applicable to any multi-mode mobile. Additionally, GSM and CDMA are used as examples to describe the disclosure. It is understood that the disclosure still applies to any authentication scenario between two wireless networks that have the same CN technology but different RAN technologies.
Furthermore, even though the CDMA and GSM technologies are used to describe the disclosure, the present disclosure applies to any wireless technology that can be used in a hybrid wireless network, not limited to these two particular technologies.
The present disclosure as described above thus provides an economical method and system for providing an authentication solution to a multi-mode mobile operating in a hybrid network. The present disclosure does not introduce any changes to the GSM and CDMA standards that define the protocols used to communicate between all network entities. Also, the disclosure does not introduce any change to any entity between the HMSC and the mobile.
In addition, the present disclosure provides a cost effective solution given that it does not introduce any change to existing architectures in the RAN and CN. This is a significant advantage for a network operator or service provider because there is no need for investing capital in upgrading existing equipment. The migration of the services to be supported by the new network can be achieved in a much shorter time and at a lower cost. The method and system described in the present disclosure increases the wireless coverage to operators exponentially, speeds up deployment phase, minimizes deployment expenses, eliminates core network operation expenses and provides higher quality of service for the mobile end user, therefore attracting more subscribers to operators.
Also, the present disclosure presents a solution to deploy a new radio technology into wireless networks without introducing any change to the core network. This creates a huge advantage for network operators that looking to expand their wireless service coverage of a new radio technology. The present disclosure needs very low cost and short deployment time considering that the core network does not have to be changed whatsoever. By deploying a new radio technology over an existing core network of existing technologies, major advantages are achieved at the radio access network such as higher bit rates. Other advantages are higher network capacity and increase in spectrum efficiency on the radio which leads to the ability of supporting larger number of subscribers and introducing better quality of service to the mobile user end. This means providing larger service coverage area and higher revenues to network operators.
Moreover, because no changes are made to the existing core network, the present disclosure allows the delivery of all existing CN services to any mobile in its serving area.
It will also be understood by those skilled in the art that one or more (including all) of the elements/steps of the present disclosure may be implemented using software and hardware to develop the HMSC, which will then be deployed in a wireless network at appropriate locations with the proper connections. Furthermore, while the disclosure has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure, as set forth in the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US02/37377 | 11/21/2002 | WO |
