Cellular communications system with screening of unauthorized services

{
  "publication_number": "US6032044A",
  "country": "US",
  "kind": "A",
  "title": "Cellular communications system with screening of unauthorized services",
  "abstract": "In a cellular communications system comprising a plurality of zones, details of authorized services for each mobile terminal are stored at a central register. The central register is accessed on entry of a visiting mobile terminal into that zone whereby to retrieve the service details for that mobile, the retrieved details are stored at a local register and compared with a set of services capable of being supported within the zone, and providing to the terminal information relating only to those services that are both authorized for use by the terminal and capable of support within the zone. In a preferred embodiment, information relating to a service which cannot be supported in a particular zone is not forwarded to the local register thus avoiding message rejection by the local register.",
  "claims": [
    "1. A method of screening of services made available locally to visiting mobile terminals (10) in a zone in a cellular communications system comprising a plurality of zones, the method including storing details of authorised services for each mobile terminal at a central register (17), accessing said central register on entry of a visiting mobile terminal into that zone whereby to retrieve the service details for that mobile, storing said retrieved details at a local register (16), comparing the stored details at the local register with a set of services capable of being supported within the zone, and providing to the terminal information relating only to those services that are both authorised for use by the terminal and capable of support within the zone, wherein the central register (17) contains information relating to each service authorised for use by a mobile terminal (10), and wherein each local register (16) has means for retrieving from the central register information relating only to those services that are capable of support within the zone.",
    "2. A method as claimed in claim 1, wherein services to which a mobile terminal (10) is entitled are authorised for use by that terminal only in a subset of said zones.",
    "3. A method as claimed in claim 2, wherein a roaming restriction is applied to terminal for which no services are either authorised for use or are supported within the zone.",
    "4. A method as claimed in claim 3, wherein a mapping is provided for each said terminal between the services allocated to that terminal and the services capable of support in each system zone whereby to identify respectively the services capable and incapable of support for that terminal.",
    "5. A method as claimed in claim 4, wherein said mapping further identifies services that are to be denied to a said mobile (10) in zones other than one or more selected zones whereby to effect a roaming restriction in respect of those services.",
    "6. A method as claimed in claim 1, wherein a roaming restriction is applied to terminal for which no services are either authorised for use or are supported within the zone.",
    "7. A method as claimed in claim 1, wherein a mapping is provided for each said terminal between the services allocated to that terminal and the services capable of support in each system zone whereby to identify respectively the services capable and incapable of support for that terminal.",
    "8. A method as claimed in claim 7, wherein said mapping further identifies services that are to be denied to a said mobile (10) in zones other than one or more selected zones whereby to effect a roaming restriction in respect of those services.",
    "9. A cellular communications system comprising a plurality of zones in each of which mobile terminals (10) may make calls and access services, wherein each mobile terminal is allocated to a respective zone and may enter other zones as a visitor, the system incorporating a central register (17) containing details of authorised services for each mobile terminal, and local registers one for each said zone for storing information relating to mobile terminals entering that zone as visitors, wherein each said local register (16) has means for accessing said central register (17) on entry of a visiting mobile terminal (10) into that zone whereby to retrieve the service details for that mobile terminal, means for comparing the stored details at the local register with a set of services capable of being supported within the zone, and means for providing to the terminal information relating only to those services that are both authorised for use by the terminal and capaple of support within the zone.",
    "10. A system as claimed in claim 9, wherein each local register has means for retrieving from the central register information relating only to those services that are capable of support within the zone."
  ],
  "description_excerpt": "This invention relates to cellular communications systems and in particular to the provision and control of roaming facilities in such systems.\n\nA number of cellular communications systems are currently being introduced. In Europe an operating standard known as GSM has been set up to define protocols, services and operating equipment.\n\nThe GSM Standard has been established as a means of realising a pan-European digital wireless telephony network, operating according to the set of ETSI specified protocols known as the GSM recommendations. The primary purposes of these recommendations is to provide a wireless telephony service to subscribers who are free to roam and use the same mobile equipment and one reachable by the same telephone number anywhere within the operating area. This may comprise a number of different networks within the same country, and even in a number of different countries, while subscribers receive a base level of service independent of their location. The recommendations define a GSM network to consist of a number of different types of functional elements, which may be variously combined in an indeterminate number to form a Public Land Mobile Network (PLMN). Within a given country there may be more than one PLMN, and a number of countries are signatory to a memorandum of understanding (the GSM MoU) which requires them to license and make available GSM telephony service which is interoperable with the GSM telephony services provided by the other signatory countries.",
  "cpc": [
    "H04W 8/18",
    "H04L 63/107",
    "H04M 3/436",
    "H04W 12/08"
  ],
  "ipc": [
    "H04M 3/436",
    "H04W 8/18"
  ],
  "assignees": [
    "Nortel Networks Corp"
  ],
  "inventors": [
    "John Parker Shannon",
    "John Paul Prokopenko",
    "Pradip Sheth",
    "Jane Dellipianni",
    "Gerald Feeney",
    "Hock Gan",
    "Robert Edward Lucas",
    "Lawrence Simpson"
  ],
  "filing_date": "1996-08-16",
  "publication_date": "2000-02-29",
  "grant_date": "2000-02-29",
  "priority_date": "1995-08-19",
  "application_number": "US-1191198-A",
  "family_id": "10779497",
  "cited_by_count": 77,
  "citations": [
    "US4901340A",
    "US5142654A",
    "US5428665A",
    "US5504804A",
    "US5781858A",
    "US5613213A",
    "US5497412A",
    "US5752188A",
    "US5590175A"
  ]
}