Patent Publication Number: US-2005124338-A1

Title: Network supported selection of service provider when roaming

Description:
TECHNICAL FIELD  
      The present invention relates to wireless telephony in general, and, more particularly, to a method and system that supports roaming service provider selection when a mobile terminal is roaming.  
     BACKGROUND OF THE INVENTION  
      Wireless telephones, which include both cellular telephones and the higher frequency personal communication devices are growing in numbers and also shrinking in size and weight. The growth in numbers is influenced by the convenience and the per call cost of wireless telephones with respect to pagers and wire line telephones or coin telephones for completing calls, especially when the user is away from home or office.  
      Typical wireless communication networks, such as those operating in accordance with the Digital Enhanced Cordless Telecommunications (DECT) standard, generally have a plurality of radio base stations, which may be connected to a mobile switching center, which, in turn, may be connected to, or integral with a Private Branch Exchange (PBX). Each base station covers a limited area, generally called a cell, within which a wireless communication link can be established with a mobile terminal such as a cell phone. A call in progress can be handed over from one base station to another while the mobile terminal is moving in the coverage area of the network.  
      A plurality of communication networks, such as networks installed at geographically spread sites of a company or public wireless networks each covering a particular city, for example, may form a telecommunication system to which a user or subscriber may have acquired access rights. The several networks of a system may operate in a so-called stand-alone or in a mutually interconnected configuration. In the latter case using the Public Switched Telephone Network (PSTN) or private or leased lines for the coupling of the networks, for example.  
      The home network of a user is in general the network at which subscriber specific information of a user is registered such as access rights, information for billing purposes, etc. The home network is in general the network in the coverage area of which a user lives or works and in which the mobile terminal is used for the greater part. In the other networks used by the subscriber, the subscriber is then regarded as a visitor.  
      When roaming to a different (visited) network, subscriber data is not known to the new network and, in the case of a telecommunication system having interconnected networks, the relevant data must be transferred by the telecommunication system from the home network database to the visited network database whenever the user is registered at a visited network, for example. In another embodiment the visited network has to set up inquiry calls to the home network to fetch the relevant data on a case-by-case basis, for example.  
      Generally, one of the networks is designated the home network of a user. In his home network the user is registered as a subscriber. The home network is in general the network in the coverage area of which a user lives or works and in which the telephone is used for the greater part. In the other networks the user is then regarded as a visitor.  
      Although different roaming services may operate in a common area, a subscriber may only utilize the roaming service that the subscriber&#39;s own service has a contract with. However, this prevents the subscriber from selecting, for example, a roaming service that may be less expensive or that may have a higher quality of service.  
      Thus it is a drawback of the prior art that a subscriber cannot choose a roaming service from a plurality of roaming services that are available in a given area. There is a need in the prior art for a system that supports roaming service provider selection when the mobile terminal is roaming.  
     SUMMARY  
      The following summary of embodiments of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.  
      In general terms, one embodiment of the present method is for selecting, by a mobile terminal, a roaming service provider in a telecommunications network, when the mobile terminal is roaming. The method has the steps of: communicating between a mobile terminal and current roaming service providers for a current location of the mobile terminal; providing to the mobile terminal, at least upon detecting a registration message from the mobile terminal, respective roaming service provider information associated with the current roaming service providers; selecting, based on the roaming service provider information, a respective one of the current roaming service providers; and connecting subsequent call(s) associated with the mobile terminal using the selected respective roaming service provider.  
      Also, in general terms, one embodiment of the present system is for allowing a mobile terminal to select a roaming service provider in a telecommunications network, when the mobile terminal is roaming. The system has: a mobile terminal that is operatively connected to a telecommunication network, the mobile terminal having a display; a call controller in the telecommunication network for controlling a call for the mobile terminal; a plurality of service providers in the telecommunication network, each of the service providers having respectively at least one cell in which the service provider is operational; each of the roaming service providers having respective roaming service provider information; and roaming service module in the service provider&#39;s system, the roaming service module operatively connected to at least the call controller. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.  
       FIG. 1  depicts a block diagram illustrative of one embodiment of a mobile switching center, base station and mobile terminal for use with the present method and system.  
       FIG. 2  illustrates overlapping cells of a plurality of service providers for a roaming service provider.  
       FIG. 3  illustrates a more detailed block diagram illustrative of a mobile switching center, base station, and mobile terminal according to one embodiment of the present method and system.  
       FIG. 4  illustrates a general flow chart of logical operational steps that may be followed in accordance with one embodiment of the present method and system. 
    
    
     DETAILED DESCRIPTION  
      The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate an embodiment of the present invention and are not intended to limit the scope of the invention.  
      A typical wireless communication network has three distinct elements: a mobile switching center, a plurality of base stations, which are installed throughout an area to be covered and connect directly to the mobile switching center, and mobile terminals, which connect over a wireless link, also called an air interface, to the base stations. Each base station provides service to a given area, called a cell, which is surrounded and/or overlapped by other cells of other radio base stations, i.e. a so-called multi-cell approach.  
      The radius of indoor cells typically ranges from 10 m to 100 m, whereas the radius of outdoor cells typically ranges from 200 m up to 5000 m. Users may set up and receive calls via the mobile switching center in each of the cells covered by a base station. A call in progress is handed over from one base station to another while a user is moving in the coverage area of the network.  
      Referring to  FIG. 1 , a system  100  is depicted that supports roaming service provider selection when the mobile terminal is roaming. The mobile terminal may also be referred to as mobile phone, a cell phone, mobile handset, or car phone. The system  100  has a mobile switching center (MSC)  102 . The system  100  may be, or may be part of, one or more of a telephone network, a local area network (“LAN”), the Internet, and a wireless network. In the depicted embodiment, a public switched telephone network (PSTN)  104  is connected to the MSC  102 . The PSTN  104  routes calls to and from mobile terminals via the MSC  102 . The PSTN  104  also routes calls from and to wireline stations  106 . The MSC  102  is also connected to one or more base stations (BS)  110 . Each of the base stations  110  communicates with mobile terminal(s)  112  in its service area (cell). The PSTN  104  generally can be implemented as a worldwide voice telephone network accessible to all those with telephones and access privileges (e.g., AT&amp;T long distance network).  
      Each of the mobile terminals  112  may have associated home location registers (HLR)  114  where data about each of the mobile terminals  112  resides. Some of the mobile terminals  112  may be remotely located from their home location, and in that case, a visiting location register (VLR)  116  is set up locally for each mobile terminal  112  that is visiting in its service area. HLR  114  can be implemented as a permanent SS7 database utilized in cellular networks, such as, but not limited to, for example, AMPS (Advanced Mobile Phone System), GSM (Global System for Mobile Communications), and PCS.  
      HLR  114  may be utilized generally to identify/verify a subscriber, and also contains subscriber data related to features and services. HLR  114  is generally utilized not only when a call is being made within a coverage area supported by a cellular provider of record, but also to verify the legitimacy and to support subscriber features when a subscriber is away from his or her home area. VLR  116 , on the other hand, may be implemented as a local database maintained by the cellular provider whose territory is being roamed. Mobile terminal  112  may be implemented as a cellular device, personal communication device, short message service device or wireless communications device (e.g., a wireless personal digital assistant).  
      The MCS  102  may have, or be operatively connected to, components of a system that supports roaming service for the mobile terminal that is roaming (for example, roaming service module  101  in the MCS  102  and service provider selection controller  115  in the mobile terminal  112 ).  
      Referring to  FIG. 2 , a roaming mobile terminal or station  200  may be currently located in an area  202 . This area  202 , for example, may lie within cell  204  of a first service provider  206 , within cell  208  of a second service provider  210 , and within cell  212  of a third service provider  214 . Each of the service providers  206 ,  210 ,  214  has associated therewith a respective mobile switching center  222 ,  224 ,  228  and respective system parameter information  220 ,  226 ,  230 . In the prior art the telecommunication system may have an arrangement with the first service provider  206 , and the mobile terminal  200  can only be tuned to the first service provider  206 . However, with the present method and system, the subscriber of the mobile terminal  200  may select any one of the three service providers  206 ,  210 ,  214 .  
      Referring to  FIG. 3 , a system  300  is shown that is illustrative of a mobile switching center  302  operatively connected to PSTN  304 , base station  310  (which may be one of a plurality of base stations), and mobile terminal  312  (which may be one of a plurality of mobile terminals) according to one embodiment of the present method and system. The PSTN  304  routes calls to and from mobile users through the MSC  302 , in addition to routing calls from and to wireline stations  306 . The MSC  302  may be connected to one or more base stations  310 . As depicted, the base station  310  communicates through the air to mobile terminal  312 , which may be of a cellular telephone type or of the wider bandwidth personal communication device type. Mobile terminals  312  may be wireless handsets or automobile mounted stations. At least the MSC  302  and the base station  310  are part of a telecommunication network. The MSC  302  has operatively connected thereto a VLR  316  and a HLR  314  that interface with the mobile terminal  312 .  
      An embodiment of the system for providing, by a telecommunications network, roaming service provider selection when a mobile terminal is roaming, may have the following elements.  
      The MSC  302  may have a call controller  320  that controls a call for the mobile terminal  312 . The subscriber, via a mobile terminal service provider selection controller  315  in the mobile terminal  312 , may select a roaming service provider in the telecommunications network, when the mobile terminal is roaming. The system  300  may have the mobile terminal  312  operatively connected, via a base station  310 , to the MSC  302  in the telecommunication network. There may be a plurality of service providers in the telecommunication network, each of the service providers having respectively at least one cell in which the service provider is operational (see  FIG. 2 ).  
      When the mobile phone is currently in one or more cells of the service providers, the mobile phone is in communication with each of the service providers as is known in the art. The mobile phone receives respective roaming service provider information from each of the service providers. Roaming service provider information may comprise pricing, data rates, push to talk, signal strength, etc that are stored in the system parameters database. A roaming service module  328  in the MSC  302  is operatively connected to the call controller  320 .  
      Upon moving outside the home service provider&#39;s coverage area, , the mobile terminal  312  tries to register itself to all the roaming service providers and each roaming service provider information is displayed on the display  313  at the mobile terminal  312 . The subscriber of the mobile terminal  312  then selects one of the service providers (such as service provider  311 ) in the telecommunication network  300  for a current location of the mobile terminal  312 . A respective one (such as, service provider  311 ) of the current roaming service providers may be selected via the selection controller  315  at the mobile terminal  312  based on the displayed roaming service provider information. The selection of the respective current roaming service provider  315  is communicated to MSC  302  of service provider  311 , the mobile terminal  312  is tuned to the selected service provider  311 , and the call controller  320  will connect subsequent calls associated with the mobile terminal  312  using the selected respective roaming service provider  311  or based on the mobile terminal&#39;s further instruction.  
      The subsequent calls associated with the mobile terminal  312  may be one of an incoming call and an outgoing call. The selected respective roaming service provider  311  may be used for subsequent calls associated with the mobile terminal  312  while the mobile terminal  312  is within a cell of the selected respective roaming service provider  311 . Alternatively, a respective roaming service provider  311  may be re-selected for each subsequent call associated with the mobile terminal. The subscriber of the mobile terminal  312  may instruct the mobile terminal  312  whether to always use a currently selected service provider or to re-select a service provider for future calls.  
       FIG. 4  is a block diagram depicting an embodiment of the present method. In very general terms, this embodiment of the method may have the steps of: communicating between a mobile terminal and current roaming service providers in the telecommunication network for a current location of the mobile terminal; detecting registration message from the mobile terminal (step  401 ); determining if the mobile terminal subscribes to a “service provider selection while roaming” feature (step  4011 ); if the mobile terminal does not subscribe, using the contracted service provider and tuning the mobile terminal to the contracted service provider (step  4012 ); retrieving, if the mobile terminal does subscribe, current roaming service provider information in a telecommunication network for a current location of the mobile terminal (step  403  ); displaying the retrieved roaming service provider information at the mobile terminal (step  404 ); selecting, if a plurality of service providers are displayed at the mobile terminal (step  405 ), a respective one of the current roaming service providers at the mobile terminal based on the displayed roaming service provider information (step  406 ); instructing the telecommunication network to use a currently selected service provider or to re-select a service provider for future calls (step  407 ); communicating the selection of the respective current roaming service provider to the telecommunication network (step  408 ); and connecting, by the selected respective roaming service provider, the subsequent call(s), associated with the mobile terminal (step  409 ). If there is only one service provider (usually a contracted service provider), the subsequent call(s) is connected to this contracted service provider without a selection by the mobile terminal (step  410 ).  
      The method and system of the present invention may be implemented in hardware, software, or combinations of hardware and software. In a software embodiment, portions of the present invention may be computer program products embedded in computer readable medium. Portions of the system may employ and/or comprise a set and/or series of computer instructions written in or implemented with any of a number of programming languages, as will be appreciated by those skilled in the art.  
      The embodiments and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those of skill in the art, and it is the intent of the appended claims that such variations and modifications be covered. The description as set forth is not intended to be exhaustive or to limit the scope of the invention. Many modifications and variations are possible in light of the above teaching without departing from the scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects.