Abstract:
A method and apparatus for providing policy control in a wireless communication system. A mobile station generates a resource request for a communication service, where the resource request includes an identifier uniquely identifying a type of communication service. A packet data serving node receives the resource request for the communication service and selects a policy control entity to process the resource request. The selection by the packet data serving node is based at least on the identifier. The selected policy control entity performs policy control on the resource request.

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §119  
       [0001]     This application claims priority to U.S. Provisional Application No. 60/517,454 filed Nov. 4, 2003, entitled “3GPP2 Policy Control Enhancement,” by A C Mahendran et al., bearing Atty. Docket No. 040064P1, and assigned to the assignee hereof and hereby expressly incorporated by reference herein. 
     
    
     BACKGROUND  
       [0002]     1. Field  
         [0003]     The present invention relates generally to communication systems, and, more specifically, to a method and apparatus for policy control enhancement in a wireless communication system.  
         [0004]     2. Background  
         [0005]     Wireless communication technologies have seen explosive growth over the past several years. This growth has been primarily fueled by wireless services providing freedom of movement to the communicating public as opposed to being “tethered” to a hard-wired communication system. It has further been fueled by the increasing quality and speed of voice and data communications over the wireless medium, among other factors. As a result of these enhancements in the communications field, wireless communications has had, and will continue to have, a significant impact on a growing number of the communicating public.  
         [0006]     Typically, a mobile station communicating in a wireless communication system is afforded various types of communication services, which may include SIP-based services, stream-based (streaming) services, among other types of services. The mobile station will usually generate a resource reservation request for a particular communication service, and the resource request is either accepted or rejected based upon policy control as determined by a policy decision function (PDF) that is specific to the type of service requested by the mobile station. The policy decision function will typically make a policy decision on the mobile station&#39;s resource request based at least in part upon a user profile associated with the mobile station making the resource request and network policy. Generally, however, the policy decision function does not have direct access to the user profile of the mobile station making the resource request since it is usually not involved in the user authentication process.  
         [0007]     The resource request generated by the mobile station is typically received at a packet data serving node (PDSN), which forwards the resource request to a policy decision function (PDF) that makes a policy decision of whether to grant the resource request to the mobile station. As mentioned, each policy decision function is service-specific, and only makes policy decisions for resource requests of a specific type of communication service that it handles. For example, a mobile station may request a certain amount of bandwidth allocation from the wireless communication system for a streaming service. The policy control for the allocation of bandwidth for streaming service is handled by a particular policy decision function of the network; whereas another policy decision function may handle resource requests for another type of communication service (such as SIP-based services, for example).  
         [0008]     A problem that occurs is that the packet data serving node is typically ignorant of the communication resource request service type requested by the mobile station. Consequently, the packet data serving node is not aware of which policy decision function to contact to handle the specific type of resource request initiated by the mobile station, which may decrease the expediency in which the resource request is handled. Another problem that exists is that, since the policy decision function needs to obtain the requesting mobile station&#39;s user profile to make a policy decision, the PDF&#39;s policy decision on the mobile&#39;s resource request may be impeded as a result of not having direct access to the mobile&#39;s user profile because the PDF is not involved in the user authentication process.  
         [0009]     The present invention is directed to overcoming, or at least reducing the effects of, one or more problems indicated above.  
       SUMMARY  
       [0010]     In one aspect of the invention, a method in a wireless communication system is provided. The method comprises generating a resource request for a communication service, the resource request including an identifier uniquely identifying a type of communication service and receiving the resource request for the communication service. The method further includes selecting a policy control entity to process the resource request, the selecting being based at least on the identifier, and performing policy control by the selected policy control entity on the resource request.  
         [0011]     In another aspect of the invention, an apparatus is provided. The apparatus comprises means for generating a resource request for a communication service, the resource request including an identifier uniquely identifying a type of communication service and means for receiving the resource request for the communication service. The apparatus further includes means for selecting a policy control entity to process the resource request, the selecting being based at least on the identifier, and means for performing policy control by the selected policy control entity on the resource request.  
         [0012]     In another aspect of the invention, a wireless communication system is provided. The wireless communication system comprises a mobile station for generating a resource request for a communication service, the resource request including an identifier uniquely identifying a type of communication service. A packet data serving node is provided for receiving the resource request for the communication service and selecting a policy decision function to process the resource request, the selecting being based at least on the identifier, and wherein the selected policy decision function performs policy control on the resource request.  
         [0013]     In yet another aspect of the invention, a mobile station in a wireless communication system is provided. The mobile station comprises a processor for generating a resource request for a communication service, the resource request including an identifier uniquely identifying a type of communication service. The mobile station further comprises a transmitter for transmitting the resource request for the communication service to a communication node. The communication node selects a policy control entity to process the resource request, the selecting being based at least on the identifier, and wherein the selected policy control entity performs policy control on the resource request.  
         [0014]     In yet another aspect of the invention, a computer-readable storage medium programmed with a set of instructions that perform a method is provided. The method includes generating a resource request for a communication service, the resource request including an identifier uniquely identifying a type of communication service and receiving the resource request for the communication service. The method further includes selecting a policy control entity to process the resource request, the selecting being based at least on the identifier, and performing policy control by the selected policy control entity on the resource request. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a block diagram of a wireless communication system in accordance with one illustrative embodiment of the present invention;  
         [0016]      FIG. 2  shows a more detailed representation of a mobile station that communicates in the wireless communication system of  FIG. 1 ;  
         [0017]      FIG. 3  depicts a more detailed representation of a base station within the wireless communication system of  FIG. 1 ;  
         [0018]      FIG. 4  is a block diagram illustrating a policy control architecture implemented in the wireless communication system of  FIG. 1  according to one embodiment of the present invention;  
         [0019]      FIG. 5  shows a signaling flow diagram between a mobile station and the components of the policy control architecture of  FIG. 4 ; and  
         [0020]      FIG. 6  illustrates a flow diagram of a process for providing policy control in a wireless communication system in accordance with one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0021]     Turning now to the drawings, and specifically referring to  FIG. 1 , a wireless communication system  100  is shown in accordance with one embodiment of the present invention. The wireless communication system  100  comprises a plurality of mobile stations (MS)  105  that communicate with a plurality of base stations (BS)  110 , which are geographically dispersed to provide continuous communication coverage with the mobile stations  105  as they traverse the wireless communication system  100 .  
         [0022]     The mobile stations  105  may, for example, take the form of wireless telephones, personal information mangers (PIMs), personal digital assistants (PDAs), laptop computers, or other types of computer terminals that are configured for wireless communication. The base stations  110  transmit data to the mobile stations  105  over a forward link of a wireless communication channel  115 , and the mobile stations  105  transmit data to the base stations  110  over a reverse link of the wireless communication channel  115 .  
         [0023]     In one embodiment, the wireless communication system  100  conforms generally to a release of the cdma2000 specification. Cdma2000 is a 3rd Generation (3G) wireless communication standard. In accordance with the illustrated embodiment, the wireless communication system  100  is intended to operate utilizing 3GPP2 (3 rd  Generation Partnership Project) Revision D of the cdma2000 standard. In an alternative embodiment, the wireless communication system  100  may operate in accordance with Release 6 of the W-CDMA (Wideband Code Division Multiple Access) standard, but other embodiments may be implemented in other releases of the W-CDMA standard. It will be appreciated that the embodiments described herein should be considered as exemplary rather than limiting. Accordingly, the system  100  may take the form of various other types of wireless communication systems without departing from the spirit and scope of the present invention, and, thus, need not necessarily be limited to the aforementioned examples.  
         [0024]     Each base station  110  is coupled to a base station controller (BSC)  120 , which controls connections between the base stations  110  and other communication system components of the wireless communication system  100 . The base stations  110  and the base station controller  120  collectively form a radio access network (RAN) for transporting data to and from the plurality of mobile stations  105  that communicate within the wireless communication system  100 . The base stations  110  are coupled to the base station controller  120  by backhaul communication links, which may take the form of wireline E1 or T1 links. The backhaul communication links, however, may alternatively be embodied using any one of a number of wired or wireless communication mediums including, but not necessarily limited to, microwave, optical fiber, and the like.  
         [0025]     The simplified depiction of the wireless communication system  100  in  FIG. 1  is merely for ease in conveying the present invention. It will be appreciated that the wireless communication system  100  may be configured with any number of mobile stations  105 , base stations  110 , and base station controllers  120  without departing from the spirit and scope of the present invention, and, thus, need not necessarily be limited to the example illustrated in  FIG. 1 .  
         [0026]     In the illustrated embodiment, the base station controller  120  is coupled to various communication system components to effectively extend the communication capabilities available to the mobile stations  105  communicating within the wireless communication system  100 . The communication system components include a packet data serving node (PDSN)  140 , a public switched telephone network (PSTN)  150 , and the Internet  160  for access by the mobile stations  105  communicating therein. Additionally, the wireless communication system  100  is configured with an Authentication, Authorization, and Accounting (AAA) server  170  to provide authentication and billing services for each of the mobile stations  105  communicating therein. The AAA server  170  maintains a user profile (not shown) for each of the mobile stations  105  communicating in the wireless communication system  100 . The user profile includes information on various communication services afforded to the mobile station  105  by the wireless communication system  100 , among various other information to provide authentication, authorization and accounting of the mobile station  105  by the AAA server  170 . It will be appreciated that the wireless communication system  100  may be interfaced with various other types of communication system components without departing from the spirit and scope of the present invention. Additionally, there may be a connection between the PSTN  150 , Internet  160 , and AAA server  170  to the BSC  120  directly, as opposed to being coupled to the BSC  120  through the PDSN  140  as illustrated in  FIG. 1 .  
         [0027]     Turning now to  FIG. 2 , a more detailed representation of the mobile station  105  is shown in accordance with one embodiment of the present invention. In one of its simpler forms, the mobile station  105  comprises a transmitter  205  for transmitting data over the reverse link of the wireless communication channel  115  to the base stations  110 . The mobile station  105  also includes a receiver  210  for receiving data that is transmitted from the base stations  110  over the forward link of the wireless communication channel  115 . In an alternative embodiment, the transmitter  205  and receiver  210  may be combined into a single transceiver unit as opposed to being embodied as two separate entities as illustrated in the figure. The transmitter  205  and the receiver  210  are coupled to an antenna  215  to facilitate the wireless transmission and reception of data between the mobile station  105  and the base stations  110  over the wireless communication channel  115 .  
         [0028]     The mobile station  105  further comprises a processor  220  for controlling various operating functions of the mobile station  105  and a memory  225  for storing data. In one embodiment, the processor  220  may take the form of a digital signal processor (DSP) chip. It will be appreciated, however, that the processor  220  may take the form of various other commercially-available processors or controllers.  
         [0029]     The mobile station  105  also comprises a data input  230 , coupled to the processor  220 , which provides data for transmission by the mobile station  105  to the base stations  110  over the wireless communication channel  115 . The data input  230  may take the form of a microphone or an input from a data generating device, such as a computer terminal, for example. It will be appreciated that the data input  230  may be implemented in various other forms to provide data to the processor  220 , and, thus, need not necessarily be limited to the aforementioned examples.  
         [0030]     The data received through the data input  230  is processed by the processor  220  and then forwarded to the transmitter  205  for transmission over the reverse link of the wireless communication channel  115  to the base stations  110 . Data received by the receiver  210  over the forward link of the wireless communication channel  115  from the base stations  110  is forwarded to the processor  220  for processing and then to data output  235  for presentation to the user of the mobile station  105 . The data output  235  may take the form of at least one of a speaker, visual display, and an output to a data device (e.g., a computer terminal), or any combination thereof. It will be appreciated that the data output  235  may comprise various other visual or aural perceptible devices, and, thus, need not necessarily be limited to the aforementioned examples. The simplified depiction of the mobile station  105  in  FIG. 2  is merely for ease in conveying the present invention. Accordingly, it will also be appreciated that the mobile station  105  may include other components to enable various other features and/or capabilities of the mobile station  105  than those illustrated.  
         [0031]     Referring now to  FIG. 3 , a more detailed representation of the base station  110  is shown in accordance with one embodiment of the present invention. In one of its simpler forms, the base station  110  comprises a transmitter  305  for transmitting data over the forward link of the wireless communication channel  115  to the mobile station  105 , and a receiver  310  for receiving data that is transmitted from the mobile stations  105  over the reverse link of the wireless communication channel  115 . In an alternative embodiment, the transmitter  305  and receiver  310  may be combined into a single transceiver unit as opposed to being embodied as two separate entities as illustrated. The transmitter  305  and the receiver  310  are coupled to an antenna  315  to facilitate the transmission and reception of data between the base station  110  and the mobile station  105  over the wireless communication channel  115 .  
         [0032]     The base station  110  is further configured with a processor  320  for controlling various operating functions and a memory  325  for storing data. In one embodiment, the processor  320  may take the form of a digital signal processor (DSP) chip. It will be appreciated, however, that the processor  320  may take the form of various other commercially-available processors or controllers without departing from the spirit and scope of the present invention. The base station  110  further comprises a communication interface  340  for interfacing the base station  110  to the base station controller  120 . It will be appreciated that the base station  110  may be configured with additional components to perform a variety of other functions than those illustrated.  
         [0033]     Referring back to  FIG. 1 , the PDSN  140  receives resource reservation requests for specific types of communication services desired by the mobile stations  105  within the wireless communication system  100 . The resource reservation request generated by a particular mobile station  105  may include various types of communication services afforded to the mobile station  105  by the wireless communication system  100 . For example, a resource reservation request by the mobile station  105  may include a request for 100 kbps of bandwidth for video. It will be appreciated, however, that the resource reservation request initiated by the mobile station  105  may include various other types of requests for communication services, and, thus, need not necessarily be limited to the aforementioned example.  
         [0034]     Referring now to  FIG. 4 , an exemplary block diagram of a policy control architecture for the wireless communication system  100  is shown in accordance with one embodiment of the present invention. When a mobile station  105  initiates a resource reservation request for communication services, the PDSN  140  accesses one or more policy decision functions (PDFs)  405  that make a network policy decision on a particular mobile station&#39;s resource reservation request. The PDFs  405 , in accordance with the illustrated embodiment, are configured to make policy decisions on the mobile stations&#39; resource reservation requests based at least in part upon a user profile of the particular mobile station  105  generating the request and on network policy. The PDSN  140  may access different PDFs  405  depending on the type of service (e.g., SIP-based services, streaming-based services, etc.) requested by the mobile station  105  since each PDF  405  is service-specific.  
         [0035]     Each PDF  405  is associated with at least one application function (AF)  410  for providing the resource reservation requested by the mobile station  105 . The AF  410  does not provide policy control since the AF  410  is typically not provided with access to the user profile of the mobile station  105  and network policy. It will be appreciated that the number of PDFs  405  associated with the PDSN  140  need not necessarily be limited to the example illustrated in  FIG. 4 . Accordingly, the PDSN  140  may have associated therewith more or fewer PDFs  405  than the two illustrated without departing from the spirit and scope of the present invention.  
         [0036]     Referring now to  FIG. 5 , a signaling flow diagram between the mobile station  105  and the components of the policy control architecture (illustrated in  FIG. 4 ) of the wireless communication system  100  is shown in accordance with one embodiment of the present invention. At  505 , the mobile station  105  sends a Session Setup Request to the AF  410  that provides resource allocation for the communication service of the resource reservation request desired by the mobile station  105 . For example, the mobile station  105  may make a request for 100 kbps of bandwidth for video. Accordingly, in this particular example, the Session Setup Request is sent to the particular application function (AF)  410  that provides the bandwidth allocation for video to the requesting mobile station  105 . It will be appreciated, however, that the communication resource reservation request generated by the mobile station  105  may vary, and, thus, need not necessarily be limited to the aforementioned example.  
         [0037]     In response to receiving the Session Setup Request message from the mobile station  105 , the AF  410  sends a Session Setup In-Progress message to the mobile station  105 . In accordance with one embodiment, the Session Setup In-Progress message includes a Service Type, Session ID, and AF address. The Service Type identifies the type of the application service (e.g., SIP-based services, stream-based services, etc.) that is being requested by the mobile station  105 . The Session ID is a number chosen by the AF  410  to identify the particular session for the request generated by the mobile station  105 . The AF address identifies the particular AF  410  that is configured to handle the request made by the mobile station  105 . In one embodiment, the AF address may take the form of a Fully-Qualified Domain Name (FQDN). In an alternative embodiment, the AF address may take the form of an IP address. It will be appreciated, however, that the AF address need not necessarily be limited to a FQDN or IP address, but may take the form of other address types used to identify the particular AF  410  providing the particular service request without departing from the spirit and scope of the present invention.  
         [0038]     At  515 , the mobile station  105  sends a Bearer Resource Request message to the PDSN  140 . The Bearer Resource Request message includes the Service Type, Session ID, and AF address that was provided to the mobile station  105  by the AF  410  handling the particular service request at  510 . As previously mentioned, the PDSN  140  is configured with multiple PDFs  405  that are service-specific for the resource reservation request that is sent from the mobile station  105 . Based on the Service Type field in the Bearer Resource Request message sent from the mobile station  105 , the PDSN  140  has knowledge of which particular PDF  405  to query for policy control.  
         [0039]     At  520 , the PDSN  140  sends a Policy Control Request message to the PDF  405  associated with the indicated Service Type (received in the Bearer Resource Request message). According to one embodiment, the Policy Control Request message also includes the user profile associated with the particular mobile station  105  in addition to the Session ID and AF address. In one embodiment, the PDSN  140  may obtain the mobile station&#39;s user profile during the authentication phase of a packet data session establishment in the Authentication, Authorization, and Accounting (AAA) server Access-Accept from the mobile station&#39;s home AAA server  170 .  
         [0040]     At  525 , the PDF  405  sends a Get-Info Request message to the AF  410  identified by the AF address provided in the received Policy Control Request message. In one embodiment, the Get-Info request message includes the Session ID, which was also included in the Policy Control Request message, to identify the particular session that pertains to the mobile station&#39;s resource reservation request to the AF  410 . The Session ID is provided to the AF  410  such that the associated PDF  405  may obtain the session-related parameters requested by the mobile station  105  at  505 .  
         [0041]     At  530 , the AF  410  that received the Get-Info Request message sends a Get-Info reply to the PDF  405  making the request to deliver the requested session-related parameters to the PDF  405 . Upon receiving these session-related parameters from the AF  410 , the PDF  405  subsequently makes a policy decision based on the mobile station&#39;s user profile and the session-related parameters defining the network policy.  
         [0042]     At  540 , the PDF  405  indicates the policy decision (i.e., an “accept” or “reject” decision) on the mobile station&#39;s resource reservation request to the PDSN  140  via a Policy Control Reply message. If the policy decision is a “reject” decision, the PDF  405  indicates the “reject” decision in a Policy Control Status message to the AF  410  so that it can release the session for the resource reservation request initiated by the mobile station  105 . The PDSN  140  sends a Bearer Resource Reply message at  545  to the mobile station  105  indicative of the policy decision provided in the Policy Control Reply at  540 . If the policy decision is an “accept” decision, the PDF  405  may send a Policy Control Status message to the AF  410 , but the PDSN  140  allocates the appropriate bearer resource and sends the Bearer Resource Reply to the mobile station  105  at  545  to indicate the policy decision to the mobile station  105 .  
         [0043]     Referring now to  FIG. 6 , a process for providing policy control for a resource reservation request generated by the mobile station  105  is shown according to one embodiment of the present invention. At block  605 , the mobile station  105  sends a Session Setup Request to the AF  410  that provides the communication service for the resource reservation request desired by the mobile station  105 . In response to receiving the Session Setup Request message from the mobile station  105  at block  605 , the AF  410  sends a Session Setup In-Progress message to the mobile station  105  at block  610 , which includes a Service Type, Session ID, and AF address. The Service Type identifies the type of the application service (e.g., SIP-based services, stream-based services, etc.) that is being requested by the mobile station  105 . The Session ID is a number chosen by the AF  410  to identify the particular session for the request generated by the mobile station  105 . The AF address identifies the particular AF  410  that is configured to handle the request made by the mobile station  105 . In one embodiment, the AF address may take the form of a Fully-Qualified Domain Name (FQDN) or an IP address.  
         [0044]     At block  615 , the mobile station  105  sends a Bearer Resource Request message to the PDSN  140 . The Bearer Resource Request message includes the Service Type, Session ID, and AF address that was provided to the mobile station  105  by the AF  410  handling the particular service request at  510 . As previously mentioned, the PDSN  140  is configured with multiple PDFs  405  that are service-specific for the resource reservation request that is sent from the mobile station  105 . Based on the Service Type field in the Bearer Resource Request message sent from the mobile station  105 , the PDSN  140  has knowledge of which particular PDF  405  to query for policy control.  
         [0045]     At block  620 , the PDSN  140  sends a Policy Control Request message to the PDF  405  associated with the indicated Service Type (received in the Bearer Resource Request message). According to one embodiment, the Policy Control Request message also includes the user profile associated with the particular mobile station  105  in addition to the Session ID and AF address. In one embodiment, the PDSN  140  may obtain the mobile station&#39;s user profile during the authentication phase of a packet data session establishment in the Authentication, Authorization, and Accounting (AAA) server Access-Accept from the mobile station&#39;s home AAA server  170 .  
         [0046]     At block  625 , the PDF  405  sends a Get-Info Request message to the AF  410  identified by the AF address provided in the received Policy Control Request message. In one embodiment, the Get-Info request message includes the Session ID, which was also included in the Policy Control Request message, to identify the particular session that pertains to the mobile station&#39;s resource reservation request to, the AF  410 . The Session ID is provided to the AF  410  such that the associated PDF  405  may obtain the session-related parameters requested by the mobile station  105 .  
         [0047]     The AF  410  that received the Get-Info Request message sends a Get-Info reply to the PDF  405  making the request to deliver the requested session-related parameters to the PDF  405 . Upon receiving these session-related parameters from the AF  410 , the PDF  405  subsequently makes a policy decision based on the mobile station&#39;s user profile and the session-related parameters defining the network policy.  
         [0048]     At block  630 , the PDF  405  indicates the policy decision (i.e., an “accept” or “reject” decision) on the mobile station&#39;s resource reservation request to the PDSN  140  via a Policy Control Reply message. If the policy decision is a “reject” decision, the PDF  405  indicates the “reject” decision in a Policy Control Status message to the AF  410  so that it can release the session for the resource reservation request initiated by the mobile station  105 . The PDSN  140  sends a Bearer Resource Reply message to the mobile station  105  at block  635  indicative of the policy decision provided in the Policy Control Reply message. If the policy decision is an “accept” decision, the PDF  405  may send a Policy Control Status message to the AF  410 , but the PDSN  140  allocates the appropriate bearer resource and sends the Bearer Resource Reply to the mobile station  105  to indicate the policy decision to the mobile station  105 .  
         [0049]     Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.  
         [0050]     Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.  
         [0051]     The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.  
         [0052]     The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.  
         [0053]     The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.