Abstract:
The present invention relates to systems and methods for establishing a data-path between a mobile station and a home access service network gateway (“ASN-GW”). During the authentication process, a visited ASN-GW receives a first message that identifies a home ASN-GW associated with the mobile station. After the mobile station has been authenticated, the visited ASN-GW receives a first data-path request message from a base station serving the mobile station, requesting a path for data-packet communication for the mobile station that extends between base station and the visited ASN-GW. The visited ASN-GW responsively uses the received identification to send a second data-path request message to the home ASN-GW which requests a path for data-packet communication that extends between the base station and the home ASN-GW. Once the data-path has been established, the home ASN-GW may monitor and/or place restrictions on the data being transmitted to and from the mobile stations.

Description:
BACKGROUND 
       [0001]    Many people use mobile stations, such as cell phones and personal digital assistants, to communicate with cellular wireless networks, which typically provide communication services such as voice, text messaging, and packet-data communication. These mobile stations and networks typically communicate with each other over a radio frequency (RF) air interface according to a wireless protocol. Mobile stations typically conduct wireless communications with one or more base stations, each of which are arranged to send communications to and receive communications from mobile stations over the RF air interface. 
         [0002]    Each base station is in turn communicatively connected with a network entity such as a access service network gateway (ASN-GW), which may assist in providing various services, such as service flow authorization, paging, radio resource management, and handover. The ASN-GW may interface with one or more core packet data networks and/or the global Internet. As such, mobile stations can typically communicate over the one or more signaling and/or transport networks from anywhere inside the coverage area of one or more station, via the base station and the ASN-GW. 
       OVERVIEW 
       [0003]    The recent introduction of WiMAX technology promises to further increase the proliferation of wirelessly-equipped devices. WiMAX (Worldwide Interoperability for Microwave Access) is an Institute of Electrical and Electronics Engineers (IEEE) standard, designated 802.16, with the 802.16e being the current version of the standard (the terms “IEEE 802.16,” “IEEE 802.16e,” and “WiMAX” may be used interchangeably herein). WiMAX provides a robust mechanism for wireless communication between base stations and subscriber stations. In particular, WiMAX is designed to provide fixed, portable or non-line-of-sight service with a potential range of 6 miles, a potential bandwidth on the order of 40 megabits per second, and superior quality of service and security. 
         [0004]    WiMAX chipsets that provide for communication in accordance with the WiMAX protocol are becoming increasingly prevalent as standard or optional equipment not only in traditional wireless communications devices, such as cellular phones and personal digital assistants, but also in devices that, heretofore, were not used for access to telephony networks. These devices include portable music players, entertainment devices such as game players, automobiles, domestic appliances and so on. 
         [0005]    WiMAX service providers may offer different service plans to their customers to accommodate the customers&#39; needs. For example, some service plans may allow an unlimited amount of data for a higher fee, while other plans may allow a capped amount of data for a lower fee. In addition, some plans may be “family” data plans that apply to a group of WiMAX devices. 
         [0006]    The present invention relates to systems and methods for establishing a data-path between a mobile station and a home access service network gateway (“ASN-GW”) in a WiMAX network. In an embodiment of the invention, a visited ASN-GW receives a first message from an authentication, authorization, and accounting (“AAA”) server. The message includes an identification of a home ASN-GW associated with a mobile station. After the mobile station has been authenticated, the visited ASN-GW receives a first data-path request message from a base station that is serving the mobile station. The first data-path request message requests a path for data-packet communication for the mobile station that extends between base station and the visited ASN-GW. In response to receiving the first data-path request message from the base station, the visited ASN-GW uses the received identification to send a second data-path request message to the home ASN-GW. The second data-path request message requests a path for data-packet communication that extends between the base station and the home ASN-GW. Upon receipt of the data-path request message, the home ASN-GW responsively sends a data-path response message to the base station, establishing that the requested path for data-packet transmission for the mobile station extends between the base station and the home ASN-GW. 
         [0007]    Once the data-path has been established, data traffic sent to and from the mobile station travels through the home ASN-GW. As such, the home ASN-GW may monitor the amount of data being sent by the mobile station (or multiple mobile stations belonging to the same account), and perhaps impose charges and/or other penalties on the account associated with the mobile station when the mobile station is transmitting and/or receiving too much data. And many other actions may be taken instead or in addition, based upon the home ASN-GW&#39;s monitoring of the data traffic to and/or from the one or more mobile stations. 
         [0008]    These as well as other aspects and advantages will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that the descriptions provided in this overview and below are intended to illustrate the invention by way of example only and not by way of limitation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    An exemplary embodiment of the present invention is described herein with reference to the drawings, in which: 
           [0010]      FIG. 1  is a simplified block diagram of a communication system in which an embodiment of the invention can be applied. 
           [0011]      FIG. 2  is a simplified block diagram of a visited ASN-GW arranged to implement aspects of an embodiment. 
           [0012]      FIG. 3  is a simplified block diagram of a home ASN-GW arranged to implement aspects of an embodiment. 
           [0013]      FIG. 4  is a simplified flow chart depicting functions that can be carried out in accordance with an embodiment. 
           [0014]      FIG. 5  is a simplified flow chart depicting functions that can be carried out in accordance with an embodiment. 
           [0015]      FIG. 6  is a simplified flow chart depicting functions that can be carried out in accordance with an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Referring to the drawings,  FIG. 1  depicts a WiMAX communication system in which aspects of the exemplary embodiment can be applied. It should be understood, however, that this and other arrangements and functions described herein are presented for purposes of example only, and that numerous variations are possible. For instance, elements can be added, omitted, combined, distributed, reordered, or otherwise modified. Further, where this document mentions functions that can be carried out by one or more devices, systems, or other entities, it should be understood that the functions may be implemented by software (e.g., machine-language instructions stored in data storage and executed by a processor), firmware, and/or hardware. 
         [0017]    As shown in  FIG. 1 , the example WiMAX communication system includes a visited access service network (ASN)  104 , a packet-switched network  110 , and a home ASN  114 . Located on visited ASN  104  is a mobile station  102 , a base station  106 , and a visited ASN-GW  108 . Located on packet-switched network  110  is a AAA server  112 . Located on home ASN  114  is a home ASN-GW  116 . 
         [0018]    Visited ASN  104  and home ASN  114  may provide WiMAX connectivity with mobile station  102 , and may manage mobility-related functions, such as handover and mobile-IP foreign-agent support. 
         [0019]    Mobile station  102  may be a cell phone, a wirelessly-equipped personal data assistant (PDA), a laptop or any other type of wirelessly-equipped device now known or later developed. Mobile station  102  may be equipped with hardware, software, and/or other logic to communicate using WiMAX. 
         [0020]    Base station  106  may include directional antennas, power amplifiers, and associated transceiver equipment arranged to communicate with mobile stations  102  using the WiMAX protocol (and/or other protocols). Base station  106  may be a data path function entity, such as a serving data path function entity, and assist in managing and setting up data-paths needed for data-packet communication between itself and other entities, such as visited ASN-GW  108 . Base station  106  may also assist in creating tunnels with various entities for packet forwarding. 
         [0021]    Visited ASN-GW  108  may act to block or accept data packets sent to or received from mobile station  102 . Visited ASN-GW  108  may also include an authenticator to assist in authenticating mobile station  102  by exchanging extensible authentication protocol (EAP) messages with mobile station  102 , base station  106 , and/or AAA server  112 . In addition, as discussed in greater detail below, visited ASN-GW  108  may assist in establishing a data-path for mobile station  102  that extends between base station  106  and home ASN-GW  116 . Visited ASN-GW  108  may be a separate entity on visited ASN  104 , or may be incorporated into another entity, such as base station  106  or an ASN-GW located on visited ASN  104  (not shown). 
         [0022]    AAA server  112  may be any device capable of (1) determining whether mobile station  102  is authorized to access visited ASN  104  and/or home ASN  114 , and (2) identifying a home ASN-GW associated with mobile station  102 . AAA server  112  may use protocols such as RADIUS and DIAMETER for communications. AAA server  112  may keep records of a home ASN-GW associated with mobile station  102  in a database. Instead or in addition, AAA server  112  may communicate with another entity in order to identify the home ASN-GW associated with mobile station  102 . 
         [0023]    Home ASN-GW  116  may assist in providing various WiMAX services, such as AAA, context management, profile management, service-flow authorization, paging, radio-resource management, and handover. In addition, as discussed in greater detail below, home ASN-GW  116  may assist in establishing a data path for mobile station  102  that extends between base station  106  and home ASN-GW  116 . 
         [0024]      FIG. 2  is a simplified block diagram depicting functional components of visited ASN-GW  108 . As shown, visited ASN-GW  108  includes by way of example a communication interface  200 , a processing unit  202 , and data storage  206 , coupled together by a system bus, network, or other connection mechanism  204 . 
         [0025]    Communication interface  200  may include one or more communication interface mechanisms that enable the entity to communicate with various other entities. As such, the communication interface may take various well-known forms, depending on factors such as the type of communication links in use. 
         [0026]    Processing unit  202  may comprise one or more general-purpose processors (e.g., INTEL processors) and/or one or more specialized processors (e.g., digital signal processors and/or application specific integrated circuits). And data storage  206  may comprise one or more volatile and/or non-volatile storage components, such as optical, magnetic, or organic storage components and may be integrated in whole or in part with processing unit  202 . 
         [0027]    As shown, data storage  206  may hold program instructions  208  and home ASN-GW data  212 . The program instructions  208  may comprise machine-language instructions executable by processing unit  202  to carry out various functions described herein. Home ASN-GW data  212  may comprise an identification of a home ASN-GW associated with mobile station  102 . 
         [0028]      FIG. 3  is a simplified block diagram depicting functional components of home ASN-GW  116 . As shown in  FIG. 3 , home ASN-GW  116  includes by way of example a communication interface  302 , a processing unit  304 , and data storage  306 , coupled together by a system bus, network, or other connection mechanism  308 . 
         [0029]    Communication interface  302  may include one or more communication interface mechanisms that enable the entity to communicate with various other entities. As such, the communication interface may take various well-known forms, depending on factors such as the type of communication links in use. 
         [0030]    Processing unit  304  may comprise one or more general-purpose processors (e.g., INTEL processors) and/or one or more specialized processors (e.g., digital signal processors and/or application specific integrated circuits). And data storage  306  may comprise one or more volatile and/or non-volatile storage components, such as optical, magnetic, or organic storage components and may be integrated in whole or in part with processing unit  304 . 
         [0031]    As shown, data storage  306  may hold program instructions  310 , monitoring data  312 , and account data  314 . The program instructions  310  may comprise machine-language instructions executable by processing unit  304  to carry out various functions described herein. Monitoring data  312  may comprise an amount of data sent to and/or received from mobile station  102 . Account data  314  may include an identification of billable accounts associated with mobile station  102 , as well as a set of rules governing those accounts. For example, the set of rules may include a threshold amount of data that mobile station  102  is allowed to send and/or receive during a certain billing cycle. As discussed below, if mobile station  102  exceeds one or more thresholds, home ASN-GW  116  may impose penalties (e.g., charges) on mobile station  102 . 
         [0032]      FIG. 4  is a flow chart depicting in summary a set of functions that can be carried out in accordance with the exemplary embodiment. Generally,  FIG. 4  depicts a method for establishing a data-path between mobile station  102  and home ASN-GW  116 . As shown in  FIG. 4 , at block  400 , visited ASN-GW  108  receives an access-request message from mobile station  102 . The access-request message indicates that mobile station  102  is requesting permission to access the WiMAX network. The access-request message may identify the mobile station using its network access identifier (NAI), although other identifiers may be used as well. In addition, the mobile station may send the access-request message using an authentication protocol such as such as privacy and key management version 2 (PKMv2) with EAP, although other protocols may be used as well. 
         [0033]    At block  402 , visited ASN-GW  108  relays the access-request message to AAA server  112 . It should be understood that visited ASN-GW  108  may forward the access-request message from mobile station  102  to AAA server  112 , or may generate a new access-request message (for example, using RADIUS), and send that message to AAA server  112 . 
         [0034]    At block  404 , AAA server  112  receives the access-request message, and determines (1) whether mobile station  102  is authorized to access the WiMAX network, and (2) whether there is a home ASN-GW associated with mobile station  102 . AAA server  112  may determine this information by querying a database. For example, the database may include a list of mobile station NAIs that are authorized to access the WiMAX network, as well as a list of home ASN-GWs associated with those NAIs. It should be understood that identifiers other than NAIs may be used as well. 
         [0035]    At block  406 , AAA server  112  sends an access-reply message to visited ASN-GW  108 . The access-reply message may indicate whether mobile station  102  is authorized to access the WiMAX network. In addition, the access-reply message may identify a home ASN-GW associated with mobile station  102 . Upon receiving the access-reply message, visited ASN-GW  108  may store the home ASN-GW information associated with mobile station  102 , for example, in home ASN-GW data  212 . At block  408 , visited ASN-GW  108  sends a message to mobile station  102  and base station  106  indicating whether mobile station  102  has been granted access to the WiMAX network. 
         [0036]    At block  410 , visited ASN-GW  108  receives a first data-path request message from base station  106 . The first data-path request message requests a path for data-packet communication for mobile station  102  that extends between base station  106  and visited ASN-GW  108 . At block  412 , in response to receiving the first data-path request message, visited ASN-GW  108  determines whether there is a home ASN-GW associated with mobile station  102  (for example, by querying home ASN-GW data  212 ). When there is a home ASN-GW associated with mobile station  102 , visited ASN-GW  108  sends a second data-path request message to home ASN-GW  116 . The second data-path request message requests a path for data-packet communication for mobile station  102  that extends between base station  106  and home ASN-GW  1   16 . 
         [0037]    At block  414 , in response to the receiving the second data-path request message from visited ASN-GW  108 , home ASN-GW  116  responsively sends a data-path response message to base station  106 . The data-path response message establishes that the requested path for data-packet transmission for mobile station  102  extends between base station  106  and home ASN-GW  116 . Thereafter, all data-packets transmitted to or from mobile station  102  pass through home ASN-GW  116 . 
         [0038]    At block  416 , home ASN-GW  116  associates mobile station  102  with a billable account, and determines whether a fee may be charged to the billable account based on an amount of data transmitted to the mobile station and/or an amount of data transmitted from the mobile station. At block  418 , home ASN-GW  116  monitors and records the amount of data transmitted to and/or from mobile station  102  over a period of time (for example, over a billing cycle). At block  420 , home ASN-GW  116  compares the amount of data transmitted to and/or from mobile station  102  to a threshold amount, in order to determine whether to penalize the account associated with mobile station  102 . 
         [0039]    At block  422 , if the amount of data transmitted to and/or from mobile station  102  is greater than the threshold amount, home ASN-GW  116  may impose a penalty on mobile station  102 . For example, the penalty may comprise sending a simple message (such as a text message) to mobile station  102 , warning the user of mobile station  102  that she has exceeded her monthly allotment of data transmission. As another example, the penalty may comprise home ASN-GW  116  blocking the transmission of data to and from the mobile station  102 . As yet another example, the penalty may comprise home ASN-GW  116  transmitting data to the mobile station at a reduced data transmission rate. 
         [0040]    If there are multiple mobile stations associated with a single billable account (i.e., the account is a family plan), steps  400 - 416  may be applied for each of those mobile stations, such that a data-path for each mobile station associated with the single billable account extends to the same home ASN-GW. For steps  418 - 22 , the home ASN-GW may monitor and record the collective data transmitted to and/or from all of the mobile stations associated with the single billable account. Consequently, home ASN-GW  116  may determine whether to penalize the account (discussed above with respect to block  420 ) based on the amount of data transmitted to and/or from all mobile stations associated with the single account. 
         [0041]      FIG. 5  is a flow chart depicting in summary a set of functions that can be carried out in accordance with the exemplary embodiment. Generally,  FIG. 5  depicts a subset of steps described in  FIG. 4  that may be carried out by visited ASN-GW  108 . As shown in  FIG. 5 , at block  500 , visited ASN-GW  108  receives a first message from AAA server  112 . The first message may comprising an identification of a home ASN-GW associated with a mobile station  102  (for example, home ASN-GW  116 ). Visited ASN-GW  108  may store the received identification information in home ASN-GW data  212 . At block  502 , visited ASN-GW  108  receives a first data-path request message from base station  106 , which is serving the mobile station  102 . The first data-path request message requests a path for data-packet communication for mobile station  102  that extends between base station  106  and the visited ASN-GW  108 . At block  504 , in response to receiving the first data-path request message from base station  106 , visited ASN-GW  108  uses the received identification information stored in home ASN-GW data  212  to send a second data-path request message to the home ASN-GW associated with mobile station  102  (in this example, home ASN-GW  116 ). The second data-path request message requests a path for data-packet communication for mobile station  102  that extends between base station  106  and home ASN-GW  116 . 
         [0042]      FIG. 6  is a flow chart depicting in summary a set of functions that can be carried out in accordance with the exemplary embodiment. Generally,  FIG. 6  depicts a subset of steps described in  FIG. 4  that may be carried out by AAA server  112 . As shown in  FIG. 6 , at block  600 , AAA server  112  receives a first message from visited ASN-GW  108 . The first message seeks to provide mobile station  102  with access to a network. At block  602 , in response to receiving the first message, AAA server  112  identifies a home ASN-GW (in this example, home ASN-GW  116 ) associated with mobile station  102 . As described above, AAA server  112  may identify the home ASN-GW by querying a database. At block  604 , AAA server  112  sends a message to visited ASN-GW  108 . The message may comprise of an identification of the home ASN-GW associated with mobile station  102  (in this example, home ASN-GW  116 ), as well as an indication of whether mobile station  102  should be granted access to the network. 
         [0043]    Example embodiments of the present invention have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to these embodiments without departing from the true scope and spirit of the invention, which is defined by the claims.