Method for call establishment

Details Method for call establishment Method for call establishment

1995-02-23

1997-02-04

Kuntz, Curtis

Telephonic communications

Having light wave or ultrasonic link for speech or paging...

Including fiber optic link within telephone network

379 59, 455 331, H04Q 722

Patent

active

056007051

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The invention relates to a method for call establishment in a cellular radio system comprising a mobile services switching centre and a private branch exchange connected thereto, and a visitor location register for storing subscriber and location data on subscribers located within the service area of the mobile services switching centre, in which method: the mobile services switching centre is requested to establish a call to a subscriber, the mobile services switching centre requests the visitor location register to provide location data of the subscriber.


BACKGROUND OF THE INVENTION

Various cellular radio systems or mobile telephone systems are in use and being designed in which the geographic coverage area of the system is divided into smaller separate service areas, i.e. cells, in such a way that when the radiotelephone or mobile telephone is located in a cell, it communicates with the fixed network through a fixed radio station incorporated in the cell. The mobile telephones belonging to the system can roam freely within the area of the network from one cell to another. One such system is the digital mobile telephone system GSM (Global System for Mobiles).
Cordless telephone (CT) systems, such as the DECT system, have recently come out on the market. The DECT system comprises a base station, which is normally based on access to an existing fixed telephone network. There are three main types of base stations: a residential base station, a base station connected to a private branch exchange in an office, and telepoint base stations.
Cordless telephone systems can also be connected to mobile telephone networks, for instance to the GSM system. The private branch exchange (PBX) of a cordless telephone system can be connected to the GSM system for example by using "DSS 1, Q.930-Q.940, 1989, Digital Subscriber Signalling System No. 1, Network Layer, User-Network Management, CCITT" signalling supplemented with mobility management messages. The PBX of a cordless telephone system is connected to the switching centre of the GSM system such that the subscribers in the PBX can roam within the service area of the GSM system, and the subscribers in the PBX can make use of the mobility management procedures of the GSM system and roam within the service area of DECT systems connected to the GSM system. In such a case, mobile subscribers are attached to the PBX in accordance with the DECT radio path protocol "ETS 300175, Radio Equipment and Systems (RES), Digital European Cordless Telecommunications (DECT), Common Interface", for instance. It has also been possible to connect fixed subscribers to the PBX, for example in accordance with the ISDN signalling protocol. In that event, also calls originating from the GSM system or from a GSM-connected telephone network can be routed to subscribers, for instance DECT subscribers, located within the service area of the PBX.
In the prior art solution, in the case of an incoming call to the PBX, register interrogation procedures in accordance with the GSM recommendations are performed, irrespective of the location of the called subscriber. FIG. 1a shows call establishment procedures in accordance with the prior art. When the call arrives at a first mobile services switching centre, which may be a gateway mobile services switching centre (GMSC), the GMSC requests 101 for routing information from the home location register (HLR) of the called subscriber by sending a SEND.sub.-- ROUT.sub.-- INFO message. The home location register HLR checks the subscriber data from its subscriber database and sends 102 a roaming number request PROV.sub.-- ROAM.sub.-- NUM to the visitor location register VLR of the location area of the subscriber, and the VLR sends 103 a roaming number and routing information as an acknowledgement ROAM.sub.-- NUM.sub.-- ACK to the home location register HLR. The home location register HLR further sends 104 the routing information and roaming number as an acknowledgement ROUT.sub.-- INFO.sub.-- ACK to the gateway mobile services switching

REFERENCES:
patent: 5400390 (1995-03-01), Salin
patent: 5428665 (1995-06-01), Lantto
European Telecommunication Standard 300 175 (parts numbered ETS 300-175-1 through ETS 300 175-9), Oct. 1992.
"Digital Subscriber signalling System, No. 1, (DDS 1), Network Layer User-Network Management" CCITT, vol. VI--Fascicle VI, 11, 14-25 Nov. 1988.
"Specifications of Signalling System No. 7," CCITT, vol. VI--Fascicle VI, 8, 14-25 Nov. 1988.
GSM 09.02--version 3.8.0: Jan. 1991, pp. 379-382, p. 406.
ETSI, GEM 01.04/18, Version 2.00.00.
GSM 03.08--version 3.7.0: Jan. 1991, p. 18.

Affiliated with

Also associated with

Rating

Method for call establishment does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method for call establishment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for call establishment will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-686861