Method for establishing an inbound call to the mobile telephone in a GSM cellular mobile telephone network

• US 5,400,390 A
• Filed: 03/09/1993
• Issued: 03/21/1995
• Est. Priority Date: 06/06/1991
• Status: Expired due to Term

• Current Assignee: Nokia Telecommunications Oy (Nokia Corporation)
• Original Assignee: Nokia Telecommunications Oy (Nokia Corporation)
• Inventors: Salin, Hannu P.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US07/971,763
• Time in Patent Office: 742 Days
• Field of Search: 379/56, 379/58, 379/57, 379/59, 379/60, 379/61, 380/21, 455/33.1, 455/34.1, 455/77
• US Class Current: 455/433
• CPC Class Codes: H04W 4/16 Communication-related supplementary services, e.g. call-transfer or call-hold
• CPC Class Codes: H04W 8/12 between location registers or mobility servers
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A method for setting up an inbound call to a mobile telephone MS in a cellular mobile telephone network. In the method, a mobile switching center (MSC) requests a home location register (HLR) to provide call routing information, the home location register (HLR) in turn requesting routing information from the visitor location register (VLR) within the location area of which the mobile telephone is currently located, and forwards the received roaming number to the switching center (MSC) for routing the call to the switching center of the current location area and further to the called mobile telephone. To avoid superfluous signalling, when the HLR detects a call transfer operation activated for a respective MS to a call transfer number, the HLR initiates independently a new roaming number request with this call transfer number at least in the case that the call transfer number belongs to another MS in the same HLR.

Claims

1. A method for setting up an inbound call to a mobile telephone in a cellular mobile telephone network comprising a home location register for permanently storing location and subscriber data on mobile telephones registered with the network, the geographic coverage area of the network being divided into smaller service areas each comprising a mobile switching centre and a visitor location register for temporarily storing subscriber data on mobile telephones currently located within said service area, the geographic coverage area of each service area being further divided into radio cells each comprising at least one fixed radio station capable of establishing a radio link with the active mobile telephones currently located in the radio cell, in which the method comprises the steps of

a mobile switching centre receives the subscriber number of the mobile telephone and requests the home location register to provide call routing information,

the home location register requests a roaming number from the visitor location register within the service area of which the mobile telephone is currently located,

the home location register receives from the requested visitor location register information that there is a call transfer operation activated for said mobile telephone to a call transfer number,

the home location register initiates independently a new roaming number request for said call transfer number, and

the home location register forwards the obtained roaming number to said mobile switching centre for call routing of a respective call to a respective mobile telephone.

2. A method for setting up an inbound call to a mobile telephone in a cellular mobile telephone network comprising a home location register for permanently storing location and subscriber data on mobile telephones registered with the network, the geographic coverage area of the network being divided into smaller service areas each comprising a mobile switching centre and a visitor location register for temporarily storing subscriber data on mobile telephones currently located within said service area, the geographic coverage area of each service area being further divided into radio cells each comprising at least one fixed radio station capable of establishing a radio link with the active mobile telephones currently located in the radio cell, in which the method comprises the steps of

a mobile switching centre receives the subscriber number of the mobile telephone and requests the home location register to provide call routing information,

the home location register requests a roaming number from the visitor location register within the service area of which the mobile telephone is currently located,

when the home location register receives, upon requesting a roaming number from the visitor location register, a response that the mobile telephone is inactive, and when the home location register contains a call transfer operation activated for the called mobile telephone to a call transfer number of another mobile telephone not belonging to the same home location register, the home location register sends the call transfer number to said mobile switching centre.

3. A method for setting up an inbound call to a mobile telephone in a cellular mobile telephone network comprising a home location register for permanently storing location and subscriber data on mobile telephones registered with the network, the geographic coverage area of the network being divided into smaller service areas each comprising a mobile switching centre and a visitor location register for temporarily storing subscriber data on mobile telephones currently located within said service area, the geographic coverage area of each service area being further divided into radio cells each comprising at least one fixed radio station capable of establishing a radio link with the active mobile telephones currently located in the radio cell, in which the method comprises the steps of

a mobile switching centre receives the subscriber number of the mobile telephone and requests the home location register to provide call routing information,

the home location register requests a roaming number from the visitor location register within the service area of which the mobile telephone is currently located,

when the home location register receives, upon requesting a roaming number from the visitor location register, a response that the mobile telephone is inactive and when the home location register contains a call transfer operation activated for the called mobile telephone to a call transfer number of another mobile telephone belonging to the same home location register, the home location register requests independently the visitor location register within the location area of which said other mobile telephone is currently located to provide a roaming number of said other mobile telephone,

the home location register forwards the obtained roaming number to said mobile switching centre for call routing of a respective call to a respective mobile telephone.

4. A method for setting up an inbound call to a mobile telephone in a cellular mobile telephone network comprising a home location register for permanently storing location and subscriber data on mobile telephones registered with the network, the geographic coverage area of the network being divided into smaller service areas each comprising a mobile switching centre and a visitor location register for temporarily storing subscriber data on mobile telephones currently located within said service area, the geographic coverage area of each service area being further divided into radio cells each comprising at least one fixed radio station capable of establishing a radio link with the active mobile telephones currently located in the radio cell, in which the method comprises the steps of:

a mobile switching centre receives the subscriber number of the mobile telephone and requests the home location register to provide call routing information,

the home location register request a roaming number from the visitor location register within the service area of which the mobile telephone is currently located,

when the home location register receives, upon requesting a roaming number from the visitor location register, a response that the mobile telephone is inactive, and when the home location register contains a call transfer operation activated for the called mobile telephone to any call transfer number, the home location register always initiates independently a new roaming number request with this call transfer number, in response to which

(a) if a roaming number is obtained, the home location register sends it to the mobile switching centre as an acknowledgement, or

(b) if the roaming number request fails and no roaming number is obtained, the home location register sends the call transfer number to the mobile switching centre as an acknowledgement.

5. A method for setting up an inbound call to a mobile telephone in a cellular mobile telephone network comprising a home location register for permanently storing location and subscriber data on mobile telephones registered with the network, the geographic coverage area of the network being divided into smaller service areas each comprising a mobile switching centre and a visitor location register for temporarily storing subscriber data on mobile telephones currently located within said service area, the geographic coverage area of each service area being further divided into radio cells each comprising at least one fixed radio station capable of establishing a radio link with the active mobile telephones currently located in the radio cell, in which the method comprises the steps of:

a mobile switching centre receives the subscriber number of the mobile telephone and requests the home location register to provide call routing information,

the home location register requests a roaming number from the visitor location register within the service area of which the mobile telephone is currently located,

the home location register determines that there is a call transfer operation activated for said mobile telephone to a call transfer number,

the home location register immediately searches independently from its data file the roaming number previously assigned and stored for said call transfer number,

the home location register forwards the obtained roaming number to said mobile switching centre for call routing of a respective call to a respective mobile telephone.

6. A method for setting up an inbound call to a mobile telephone in a cellular mobile telephone network comprising a home location register for permanently storing location and subscriber data on mobile telephones registered with the network, the geographic coverage area of the network being divided into smaller service areas each comprising a mobile switching centre and a visitor location register for temporarily storing subscriber data on mobile telephones currently located within said service area, the geographic coverage area of each service area being further divided into radio cells each comprising at least one fixed radio station capable of establishing a radio link with the active mobile telephones currently located in the radio cell, in which the method comprises the steps of

a mobile switching centre receives the subscriber number of the mobile telephone and requests the home location register to provide call routing information,

the home location register requests a roaming number from the visitor location register within the service area of which the mobile telephone is currently located,

the home location register determines that there is a call transfer operation activated for said mobile telephone to a call transfer number,

the home location register initiates independently a roaming number request for said call transfer number, and

the home location register forwards the obtained roaming number to said mobile switching centre for call routing a respective call to a respective mobile telephone.