The present invention relates generally to cellular access networks, and in particular to supporting mobility across different cellular access networks.
Modem wireless communication networks are generally structured vertically, with a different network infrastructure required for each wireless access technology. For example,
Further, the structural differences between the individual access networks in the overall network 100 require different protocols, procedures, and mechanisms for functions such as identification, addressing and AAA (Authentication, Authorizing, Accounting). For example, consider the significant structural differences between the following individual networks that are illustrated in
A) A mobile station (MS) 105 participating in a third generation (3G) Universal Mobile Telecommunications System (UMTS) network, including High Speed Downlink/Uplink Packet Access (HSDPA/HSUPA) communicates wirelessly with a base station referred to as a Node B 110. The Node B 110 is in turn connected to a Radio Network Controller (RNC) 115, which is connected to a Serving GPRS Support Node (SGSN) 120. The SGSN 120 then connects to a Gateway GPRS Support Node (GGSN) 125, which finally connects to an IP network.
B) A MS 105 participating in a 3G Code Division Multiple Access (CDMA) network using EVolution Data Only (EVDO) technology communicates wirelessly with a Base Transceiver Station (BTS) 130. The BTS 130 is then connected to a Base Station Controller (BSC) 135. The BSC 125 is connected to a Packet Data Serving Node (PDSN) 140, which finally connects to an IP network.
C) A MS 105 participating in a Wireless Local Area Network (WLAN) communicates wirelessly with an Access Point (AP) 145. The AP 145 is then connected to a WLAN GateWay (WLAN/GW) 150, which finally connects to an IP network.
D) A MS 105 participating in a WiMAX network communicates with a WiMAX Base Transceiver Station (WiMAX BTS) 155. The WiMAX BTS 155 is then connected to a WiMAX Base Station Controller/GateWay (WiMAX BSC/GW) 160, which finally connects to an IP network.
Supporting seamless mobility of MSs 105 across different networks and different interfaces, such as those described above, is very challenging. Often numerous interworking gateways need to be deployed and numerous interworking policies need to be managed. Further, it can be very difficult to leverage common aspects of different networks and interfaces, resulting in duplication of numerous infrastructure functional elements. Thus in some cases seamless mobility across different networks and interfaces can be cost prohibitive.
According to one aspect, the invention is a system for integrated cellular access routing. The system includes a mobility router and first and second media access controllers operatively connected to the mobility router. A first connectivity manager is operatively connected to both the mobility router and to the first and second media access controllers. Thus a mobile station can maintain a single Internet Protocol (IP) connectivity context when the mobile station roams, from a connection to a first interface module controlled through the mobility router by the first media access controller, to a connection to a second interface module controlled through the mobility router by the second media access controller.
According to another aspect, the invention is a method for integrated cellular access routing. The method includes receiving at a mobility router a first backhaul communication transmitted from a first interface module, and routing the first backhaul communication from the mobility router to a first media access controller operatively connected to a connectivity manager. Then a first Internet Protocol (IP) connectivity context associated with the first backhaul communication is identified at the connectivity manager. A second backhaul communication, transmitted from a second interface module, is then received at the mobility router and routed to a second media access controller operatively connected to the connectivity manager. The connectivity manager then identifies that the second backhaul communication is also associated with the first IP connectivity context. Thus the connectivity manager identifies that both the first and second backhaul communications are associated with a single Mobile Station (MS), and the MS is then able to roam from a connection to the first interface module to a connection to the second interface module.
Therefore, according to particular embodiments of the present invention, a common access network solution provides seamless IP connectivity to MSs using different air interfaces. For each MS, one IP connectivity context can be maintained, including information regarding, for example, IP addresses, authentication, and Quality of Service (QoS), which enables centralized management of AAA (Authentication, Authorization, and Accounting) and seamless mobility across multiple air interfaces.
In order that the invention may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures, wherein like reference numbers refer to identical or functionally similar elements throughout the separate views. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present invention, where:
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a system and method for integrated cellular access routing. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises a . . . ” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
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The iCAR 200 provides media-specific (i.e., air interface specific) controller and mobility functions. The iCAR 200 also enables seamless IP connectivity and handovers for MSs 105 across a plurality of different access media or air interfaces. Seamless IP connectivity functions of the iCAR 200 include, for example, registration and identification of MSs 105, and management of: addressing, AAA, Quality of Service (QoS), security, mobility and policies that are all common for all air interfaces.
Referring to
The mobility router 300 is also operatively connected to a plurality of media access controllers 310-n. Each media access controller 310-n provides a medium-specific interface that communicates with a particular type of standard network interface module. For example, a media access controller 310-1 can communicate with UMTS Node Bs 110, a media access controller 310-2 can communicate with CDMA BTSs 130, and a media access controller 310-3 can communicate with WLAN APs 145. Each media access controller 310-n is operatively connected to a media specific database 315 for storing data concerning communications with a specific type of network interface module. Further, an IP connectivity database 320 is operatively connected to the mobility router 300, and stores data concerning, for example, routing different data types to different media access controllers 310-n.
In operation with the access controllers 310-n, the mobility router 300 also provides mobility aware routing and multicast functions. The mobility router 300 further performs IP paging and media-independent fast handovers between interface modules. Such media-independent fast handovers are enabled by a centralized connectivity manager 325 that maintains, in an IP forwarding database 330, all data concerning both a present interface module and a handover candidate interface module.
The connectivity manager 325 is operatively connected to the mobility router 300 and to each of the media access controllers 310-n. The connectivity manager 325 provides a single IP connectivity context for each MS 105 that is operatively connected to the iCAR 200. The single IP connectivity context comprises information that enables a MS 105 to roam from one standard network interface module to another. For example, a single IP connectivity context enables a MS 105 to roam from a CDMA BTS 130 to a WLAN AP 145.
A single IP connectivity context can include one or more IP addresses. Thus a MS 105 can use any of a plurality of IP addresses allocated to it, over multiple interface modules, during a single communication session. The multiple IP addresses are then transparent to any particular interface module.
Further, according to an embodiment of the present invention, a single IP connectivity context can be associated with all the information necessary to enable a MS 105 to perform a single sign-on process (e.g., including authentication and authorization) that enables seamless mobility across different interface modules. The information associated with an IP connectivity context can include for example interface identifications, identities, IP addresses, authentication data, QoS data, and policies.
An IP forwarding database 330 is operatively connected to the connectivity manager 325 and stores information concerning, for example, protocol support across multiple interface modules. The various protocols managed by the connectivity manager can include for example Point to Point Protocol (PPP), Packet Data Convergence Protocol (PDCP), and RObust Header Compression (ROHC).
The iCAR 200 according to the present embodiment is connected to a managed IP network 335 through the mobility router 300. The managed IP network 335 is then connected to a core network 340 and to other entities such as a Common Access Network for managing AAA (CAN-AAA) 345 and a CAN providing an Operation and Maintenance Center (CAN-OMC) 350. The iCAR 200 also can be connected to other iCARS 200, either through a managed IP network 340 or using a direct connection between connectivity managers 325.
According to yet another embodiment of the present invention, a MS 105 that is operatively connected to an iCAR 200 can access multiple interface modules simultaneously using multiple IP addresses. For example, a voice session can proceed using WiMAX, and a simultaneous file transfer session can proceed using WiFi. Thus both sessions continue to use the same IP connectivity context independently of an interface module.
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Advantages of embodiments of the present invention therefore include a common access network solution that provides seamless IP connectivity to MSs 105 using different air interfaces. An iCAR 200, according to an embodiment of the present invention, thus supports scalable and flexible network models—both centralized and distributed—and avoids complex inter-working gateway infrastructures.
It will be appreciated that embodiments of the invention described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of integrated cellular access routing as described herein. The non-processor circuits may include, but are not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power source circuits, and user input devices. As such, these functions may be interpreted as steps of a method for integrated cellular access routing. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used. Thus, methods and means for these functions have been described herein. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all of the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims.