Abstract:
A core network architecture for supporting an internet protocol based network is disclosed. The system includes a base station which is configured to convert a signal from a first network to an internet protocol network signal and send the converted signal through the internet protocol base network. The network also includes a gateway which is configured to receive the converted signal and deploy the converted signal through the internet protocol base network. In this sense, the internet protocol base network manages the call mobility and delivery of the signal. The base station in this disclosure may be a femto base station and the first network may be a code division multi-access (CDMA) network.

Description:
CROSS REFERENCE TO RELATED PATENTS AND APPLICATIONS 
       [0001]    This application is related to U.S. application Ser. No. ______, filed Jun. 1, 2007, entitled “METHOD TO ALLOW HAND-OFF OF A CDMA MOBILE FROM IMS FEMTOCELL TO CIRCUIT MSC, Inventor Thompson, Attorney Docket No. Thompson 27/LUTZ 2 00528, and U.S. application Ser. No. ______, filed Jun. 1, 2007, entitled “METHOD AND APPARATUS TO ALLOW HAND-OFF FROM A MACROCELL TO A FEMTOCELL, Inventor Burgess and Thompson, Attorney Docket No. Burgess 14-25/LUTZ 2 00526. These applications are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE DISCLOSURE 
       [0002]    This disclosure relates to an apparatus and method for supporting and converting a signal in one network to another. More particularly, this disclosure relates to a method and apparatus for converting a signal in a first network, i.e. Code Divisional Multi-access (CDMA) network to an Internet protocol Multimedia Subsystem (IMS) network. 
         [0003]    While the disclosure is particularly directed to telecommunications architecture and will thus be described with specific reference thereto, it will be appreciated that the disclosure may have usefulness in other fields and applications. For example, this disclosure may be used in variety of data transfer systems in order to support the gradual migration of one network entity to another thereby allowing service providers to invest their energy in future IMS technology. 
         [0004]    By way of background, CDMA mobiles are in use all over the world. Many people use these handsets in order to transfer voice and data through a well established radio network. Currently, there are many methods for configuring voice path handoffs across the CDMA radio network. 
         [0005]    The IMS/Session Initiation Protocol (SIP) based network is an internet based network that supports many other types of handsets. These handsets use Voice over Internet Protocol (VoIP) and other methods to transfer data voice and real time applications across Internet Protocol (IP) network. Although the IMS network is less commonly used in order to transfer voice and data, it is gaining popularity over other networks. 
         [0006]    Currently in the industry there is no effective way to convert a signal from one network to an IMS network. The current systems in place only allow IP signals to be covered on the IP network. There is a need in the industry to allow IMS network coverage and capacity to be extended to signals originally made to be transferred over other networks. There is a further need for these signals to be converted and received on an IMS network and managed though seamless means. There is also a need for an architecture which will allow handoffs from the IMS network to the networks and from these other networks to IMS networks. 
         [0007]    Furthermore, data is a large component of third generation wireless systems. However, much of the third generation wireless architecture is only optimized for voice and not for data. This causes problems with latency and data performance. Therefore, there is a need in the industry to supply a data network and allow for IP awareness to take place on the CDMA network. 
         [0008]    The present invention contemplates a new and improved architecture that resolves the above-referenced difficulties and others. 
       SUMMARY OF THE INVENTION 
       [0009]    An apparatus for core network architecture that enables and supports gradual migration to and from internet protocol based network is provided. The disclosure will allow for the conversion of a call that originated in a first network to be carried and processed to an internet protocol based network without changing or manipulating the mobile unit or the current network architecture in place. 
         [0010]    In one aspect of the disclosure the system includes a core network architecture for supporting seamless migration to and from an internet protocol based network. The core network architecture comprises a base station configured to convert a signal from a first network signal to an internet protocol network signal and send the converted signal via the internet protocol based network and a network gateway configured to receive the converted signal and deploy the converted signal through the internet protocol based network which manages the call mobility and delivery of the signal. 
         [0011]    In accordance with another aspect of the present disclosure, the system includes a femtocell base station as the base station. 
         [0012]    In accordance with another aspect of the present disclosure, the system includes that the first network is CDMA network. 
         [0013]    In accordance with yet another aspect of the present disclosure, the system further includes an operations administration and management server configured to initialize relevant data associated with the converted signal. 
         [0014]    In another aspect of the present disclosure the system includes that the relevant data comprises power settings, a Pseudo random Number (PN) offset information and a neighborhood list. 
         [0015]    In accordance with another aspect of the present disclosure, the system includes a feature server which is configured to provide supplemental services associated with the converted signal. The supplemental services may include call waiting, caller ID, three way calling, etc. 
         [0016]    In accordance with yet another aspect of the present disclosure, the system further includes a mobile switching center emulator which is configured to facilitate with authenticating the mobile unit. 
         [0017]    In accordance with another aspect of the present disclosure, a method includes converting a call from a first network to an internet protocol based network. The method comprises establishing a call on the first network that is within the service range of a base station, converting the call from the first network to an internet protocol based network via the base station and forwarding the converted call through the internet protocol based network. 
         [0018]    In accordance with yet another aspect of the present disclosure, the method includes the first network being a CDMA network. 
         [0019]    In accordance with another aspect of the present disclosure, the method includes that the call is first established on a CDMA mobile station. 
         [0020]    In accordance with another aspect of the present disclosure, the method would include that the base station be a femto base station. 
         [0021]    In accordance with yet another aspect of the present disclosure, the method would include autoconfiguring data associated with the call. 
         [0022]    In accordance with another aspect of the present disclosure, the method includes maintaining the call while the call is converted from the first network to the internet protocol based network. 
         [0023]    In accordance with yet another aspect of the present disclosure, the system for supporting voice and data in a wireless radio broadband data standard in an associated internet protocol multimedia system comprising a base station configured to translate a call that originates from a CDMA system into SIP messaging, handoff application server configured to facilitate handoff procedures for the call, a feature server configured to provide service features for the call and a network gateway that provides security between the base station and an associated core network and forwards the call through the associated internet protocol media system. 
         [0024]    In accordance with yet another aspect of the present disclosure, the system includes that the call be originated in a CDMA network. 
         [0025]    In accordance with another aspect of the present disclosure, the system includes that the call was placed from a CDMA mobile. 
         [0026]    In accordance with yet another aspect of the present disclosure, the system further includes that the base station be a femto base station router. 
         [0027]    In accordance with yet another aspect of the present disclosure, the system includes a mobility application server which provides call management services for the call. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0028]    The presently described embodiments exist in the construction, arrangement, and combination of the various parts of the device, and steps of the method, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which: 
           [0029]      FIG. 1  illustrates a portion of the overall communication network including a mobile station, a base station, mobile switching center, a plurality of mobile gateways, an IP network and the public switch telephone network. 
           [0030]      FIG. 2  is a more detailed illustration of the overall network as shown in  FIG. 1 . 
           [0031]      FIG. 3  is a flow chart illustrating one embodiment of the method according to the present disclosure. 
           [0032]      FIG. 4  is a flow chart illustrating another embodiment of the method according to the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Referring now to the drawings wherein the showings are for purposes of illustrating the disclosed embodiments only and not for purposes of limiting the same.  FIG. 1  provides an overall view of the system into which the present disclosure may be incorporated. A communications infrastructure A is shown. The communications infrastructure A includes a mobile station  101 , a IMS network  135 , a mobile switching center  105 , a plurality of media gateways  107 ,  111 , a base station  115 , the IP network  109  and the Public Switched Telephone Network (PSTN)  113 . It should be understood that this represents but one embodiment of the communications network infrastructure A. The present disclosure could be incorporated into a variety of communication network configurations. 
         [0034]    In operation, as described in greater detail below, the presently described embodiments are directed towards a support architecture for CDMA 3G1x voice using IMS. In this sense, this disclosure describes a solution to the current problem which involves using a CDMA 3G1x voice through MSC core network, which uses a legacy circuit based solution. Because wireless service providers&#39; further plans are to evolve their core network to IMS in order to support VoIP and other multimedia services over evolution data optimized (EV-DO) rev A, this is very convenient. Therefore, it is important to have one core network which supports both 3G1x voice and VoIP over EV-DO rev A. This will prevent wireless service provides from relying on two separate core networks, one with a legacy MSC and the other on IMS. By using a system such as the one disclosed capital investments in operational costs can be greatly decreased. 
         [0035]    Still referring to  FIG. 1 , the system includes an associated CDMA 3G1x mobile station  101 . As shown, it may be connected to a base station  115 . The base station  115  in turn is being served by the IMS  135 . The mobile switching center  105  is connected via intervendor trunk to the media gateway  107 . The media gateway is in turn connected to the IP network  109 . 
         [0036]    As described in further detail below, this communication network may include other network elements, for example, switches, gateways, etc. These other communication networks may also include cellular networks, VoIP networks, the intranet, etc. 
         [0037]    Continuing on with  FIG. 1 , this embodiment includes a mobile station  101  which is user equipment. However, other user equipment besides a mobile station shown may be substituted. Other examples of user equipment include, but are not limited to, wireless phones, VoIP telephones, laptop computers, desktop computers, Wi-FI phones, etc. These devices are typical user equipment used to communicate through compatible lines. In this embodiment, the mobile station is a CDMA 3G1x handset. 
         [0038]    Through this disclosure, the call may be processed using the base station  115  in order to bypass the MSC  105  and the other network components. In this sense, after a call that is established within service range of the base station  115 , the base station  115  may handle the call. The base station  115  may convert the call from the first network (a CDMA network, shown in FIG. as Network A) to the IP network  109  and the call will be served by IMS  145 , and then forward the converted call through the IP network  109  to the media gateway  107  and through the PSTN  113 . This would eliminate the need for the legacy circuit based MSC network. 
         [0039]    The signal is divided into two portions, that bearer portion and the signaling portion. The base station  115  is used in order to convert both parts of this signal. The signal is converted in order to be processed by a SIP based system, in this embodiment the IMS  135 . On the bearer path Enhanced Variable Rate Codec/Radio Link Protocol (EVRC/RLP) is converted into EVRC/Reliable Transport Protocol (RTP) in BTS  115 . RLP is generally used for communication between a mobile station and a base station and RTP is used in multimedia real time traffic transportation. For the signaling portion the BST  115  is converting interoperability specification (IOS) to SIP. 
         [0040]    Now referring to  FIG. 2  which shows a more detailed display of the overall network.  FIG. 2  shows the elements of the two networks, network A and network B. Included in network A is a base station transceiver subsystem  103 . The base station transceiver subsystem is  103  connected to the mobile switching center  105  which was also not shown in  FIG. 1 . The final shown element of network A is the Home Location Register and Authentication Center (HLR/AC)  133 . These elements are interconnected through the ANSI-41 standards technology. This standard is well known in the art. 
         [0041]    Still referring to  FIG. 2 , network B is also shown. Network B does not have an actual MSC. Instead, the IMS  135  is acted as serving MSC in order for the mobile unit  101  to communicate without creating a change in the overall function of the mobile unit  101  or the telecommunications network. 
         [0042]    Network B includes the base station  115 , which was shown in  FIG. 1 , which is in communication with an Signaling Gateway  137 . The Signaling Gateway  137  is in communication with the IP network which has a variety of network elements which make up the IMS. These network elements include a feature server  119 , a Call Session Control Function (CSCF)  121 , a Home Subscriber Server (HSS)  123 , a Mobility Application Service (MMAS)  125  which includes a Visitor Location Register (VLR)  127  and a Handoff Application Server (HOAS)  131 . Also included in network B is a Short Message Service Center (SMSC)  129 . It should be noted that the elements in network A and network B are but one embodiment of this disclosure. These network elements may be configured in a number of ways and still fall within the spirit and scope of the claims. 
         [0043]    Still referring to  FIG. 2 , the disclosed method would eliminate the need for Network A as shown. Through this disclosure, the mobile station  101  would register with Network B through the base station  115 . The signal then would continue through the Signaling Gateway  137  and travel to the IP Network  109  for processing. The base station  115  in this embodiment would include real time transport protocol in which the signal would be transformed and communicated via SIP messaging. In this form there would be no use for ANSI-41 standard protocol. Signal would be converted from 3G1x at the base station  115 . In some embodiments the base station  115  is a femto base station. In another embodiment it is a macro base station. In any form, it is a base station that converts the signal making use of Network B without using Network A to process the call. 
         [0044]    Continuing on, in this embodiment the variety of network elements perform various functions in processing the call. The Signaling Gateway  137  performs a third generation peer to peer (3GPP2) handoff for the CDMA mobile station  101 . 
         [0045]    The HLR  133  has the mobile station  101  feature and roaming information. The HLR  133  also contains the subscriber information for the handset. The subscriber information may include complimentary feature information. The HLR  133  may also include authentication information including an A key, etc. 
         [0046]    The MSC  105  is also the home MSC for the mobile station  101  while in Network B. However, in Network B the IMS will act as the serving MSC for the mobile unit  101  while in Network B. In this sense, when the mobile station  101  roams into Network B the IMS will handle the mobile call. The mobile station  101  information will be transferred from the HLR  133  to another appropriate network element in order that the IMS can process the mobile call. 
         [0047]    In this embodiment the MMAS  125  would hold the subscriber information at least temporarily while the call is handled in Network B. The VLR  127  may be used to store the subscriber information for the IMS. 
         [0048]    Another network element in the IMS is the feature server  104 . The feature server  1119  may be used to provide supplementary service to the mobile station  101 . The supplementary service may include three way calling, call waiting, conference calling, call forwarding, etc. 
         [0049]    The CSCF  121  may be used to provide session control for the mobile call. The CSCF  121  may be used to regulate bandwidth and maintain Quality of Service (QoS) throughout the call. 
         [0050]    The HSS  123  also may be used to hold the handset subscriber information. In Network B this function was generally performed by the HLR  133 . This information would be transferred to the HHS  123  when the mobile station  101  is operating in Network B. This information may include international mobile subscriber identity, the mobile identification number filter criteria, the electronic serial number, etc. 
         [0051]    The SMSC  129  is used to interact with the MMAS  125  in order to provide short message services to the mobile station  101 . The HOAS  131  may be used to handle hand-off procedures while the mobile station  101  is in Network B. The HOAS  131  may also be used in order to perform hand-off functions when traveling between Network A and Network B. This function may also be performed by the Signaling Gateway  135 . 
         [0052]    As the case with any of these functions, implementation of the various network elements depends on how the system is used. These functions may be performed by some or all of the network elements in conjunction or separate from another. This is but one embodiment of the proposed system and variations may exist. 
         [0053]    Now referring to  FIG. 3  which is a flow chart illustrating one embodiment of the method according to the present disclosure. This embodiment is a 3G1x to SIP base station interworking. In this embodiment the base station  115  originates the call. This embodiment employs a base station mobile  101 , a femtocell base station  115 , and the IMS core which are shown in the overall communication networks in  FIGS. 1 and 2 . This method assumes that the mobile has been powered up and registration has been completed with the IMS core network. It should be understood that the method may be implemented by a variety of software and hardware configurations. It should also be understood that suitable software/hardware implementing the embodiments of the invention may also be distributed on any and/or all appropriate network elements. 
         [0054]    The method begins with a mobile user dialing a phone number and pressing “send” on the mobile station  101 . The first message  301  is the orientation with digits. This is a normal mobile origination, which is well known in the art. 
         [0055]    Message  2  is the base station acknowledgement  303 . This is also known in the art wherein the base station provides a normal CDMA radio response. 
         [0056]    Message  3  is an invite message  305 . The base station  115  translates the signal to a SIP invite. The method continues with Message  4 , channel assignment  307 . This is a known CDMA radio response that is provided by the base station  115 . The method continues with a mobile traffic preamble  309  at Message  5  and continues with Message  6 , a base station acknowledgment  311 . These are CDMA radio responses which the base station has provided. 
         [0057]    The method continues with Message  7 , session progress  313 . Provisional acknowledgement interaction is then established across the IMS core and the base station  115 . This ignites a ring back tone via the bearer path  317 . 
         [0058]    The method continues with the called party answering the phone and the IMS core sending an invite message M 8  at  319  which establishes the voice call between the mobile station  101  and the called party  321 . The method continues after the conversation has ended the mobile release on the traffic channel M 9  at  323 . This will, in turn, clear up the resources associated with the call. M 11  is the cell null traffic data at  327 . This is provided by the base station and is a normal CDMA radio response. The base station  115  will then release the mobile  101  from the IMS network M 12  at  329  and the call is released M 13  at  331 . 
         [0059]    Now referring to  FIG. 4 , which is a mobile termination on the IMS and CDMA base station. This message also begins with the assumption that the MMAS  125  ( FIG. 2 ) has registered as the serving system for the base station  115 . 
         [0060]    Ml is an incoming call to the home MSC at  401 . The home MSC then sends a locator request at  403  in order to locate the called number. This request sent to the HLR which, once the phone has registered, is aware of the location of the mobile unit linked to the number dialed. 
         [0061]    M 3  is the querying of the registered serving MSC for a temporary routing number at  405 . In this embodiment, the serving MSC is the IMS. Next, the IMS responds with the temporary routing number as message  4  at  407 . 
         [0062]    The HLR  133  then uses the temporary routing number and responds to the home MSC. Next, the home MSC routes the incoming call to the serving MSC via the temporary routing number. The media gateway  107  will then invite the called party through a SIP message at M 7   409 . Based on the temporary routing number, the invite is routed to the appropriate application server  125  ( FIGS. 1 and 2 ) at  411 . 
         [0063]    The application server  125  retrieves the VLR  127  associated with that temporary routing number at step  413  M 9 . The application server  125  then reroutes the incoming call to the called mobile based on the temporary routing number. The call is then routed to the base station  115  serving this user. At step  415  a page is then sent from the base station  115  to the mobile station  101  via the mobile identification number or international mobile station identification. The page in turn is then responded to at  417 . At  419 , the alert with info is sent to the mobile  101 . This would include any caller identification information that was linked with the call. At step  421 , a provisional acknowledgement is sent and a response is sent if appropriate. 
         [0064]    Message  11 , the base station  115  pages for the user and at message  12 . The base station  115  alerts the user including the calling party identification. This in turn brings a ring back tone via the media gateway  110  at step  427 . The user then answers the call and an answer message is sent at step  433  in message  13 . A  200  OK acknowledgment is then sent from the base station to the media gateway  112  which then sends an answer message to the home MSC which sends it to the PSTN  110  in messages  14  and  15  through steps  435  and  437 . Finally, a talk path is established at step  439 . 
         [0065]    The above description merely provides a disclosure of particular embodiments of the claimed invention and is not intended for the purposes of limiting the same thereto. As such, this disclosure is not limited to only the above-described embodiments. Rather, it is recognized that one skilled in the art could conceive alternative embodiments that fall within the scope of the invention.