Telecommunications switching system

• US 4,916,691 A
• Filed: 10/28/1988
• Issued: 04/10/1990
• Est. Priority Date: 10/28/1988
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.), Massachusetts Institute of Technology, Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.), AT&T, Inc.
• Inventors: Goodman, David J.
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): Chin, Wellington
• Application Number:
  US07/263,928
• Time in Patent Office: 529 Days
• Field of Search: 370/60, 370/94, 370/95, 370/88, 455/33, 455/34, 455/53, 455/54, 455/56, 379/59, 379/60
• US Class Current: 370/389
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks

Abstract

A switching system is described in which routing information, which may be associated with packets originating in cellular calls, is divided into information which does not change as the subscriber crosses a cell boundary, and information which does change as the subscriber crosses a cell boundary. Routing procedures associated with the information which does not change as the subscriber crosses a cell boundary are established and stored in the memory of the switch at the beginning of the call. However, routing procedures associated with the information which does change as the subscriber crosses a cell boundary may be derived from the header information of each packet as it arrives at the appropriate portion of the switch.

Claims

1. A telecommunications switching system comprising:

means for establishing a route for transmitting a number of packets of information between a first party and a second party, each packet comprising a header which contains information associated with a terminal of the first party, and information associated with a terminal of the second party,

the invention characterized in that

the established route comprises at least two segments;

the first segment of the route having associated with it constant routing information which is stored in a memory portion of the system, which routing information remains constant during transmission of the said number of packets, the headers of said number of packets having portions associated with said constant routing information, which header portions remains constant during the transmission of the said number of packets; and

,

the second segment of the route having associated with it varying routing information which may vary during transmission of the said number of packets, the headers of said number of packets having portions associated with said varying routing information, which header portions may vary from one packet to another during the transmission of the said number of the packets, corresponding to the varying routing information;

the system further comprising means for varying the header information associated with the second segment of the route.

2. The system of claim 1 wherein the means for establishing the route are different from the means for varying that portion of the header which varies during transmission of the said number of packets.

3. The system of claim 2 wherein the varying routing information is varied in response to a variation in the geographical location of one of the parties.

4. The system of claim 3 further comprising means for stimulating the transmission of packets containing the said header portions despite the absence of other information portions.