(12) United States Patent ao) Patent No.: us 6,600,757 Bi
Jones et al. (45) Date of Patent: Jul. 29,2003
(54) PAGING CHANNEL CONTROL METHOD AND APPARATUS
(75) Inventors: Edward Arthur Jones, Maldon (GB);
Gerhard Petri, Billericay (GB)
(73) Assignee: International Mobile Satellite Organization (GB)
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 08/984,325
(22) Filed: Dec. 3, 1997
(30) Foreign Application Priority Data
Dec. 3, 1996 (GB) 9625256
(51) Int. C I. II04Q 7/00
(52) U.S. CI 370/480; 370/436; 370/468;
455/450
(58) Field of Search 370/328, 329,
370/330, 331, 336, 337, 345, 347, 350, 436, 437, 468; 455/422, 426, 427, 434, 436, 450, 437, 438
(56) References Cited
U.S. PATENT DOCUMENTS
4,686,672 A 8/1987 Namiki
4,849,750 A 7/1989 Andros et al 340/825.44
5,206,855 A 4/1993 Schwendeman et al 370/50
5,258,980 A * 11/1993 Maebara et al 370/347
5,309,439 A * 5/1994 Roos 370/508
5,519,404 A 5/1996 Cances et al.
5,627,830 A * 5/1997 Kotzin 370/336
5,640,679 A * 6/1997 Lundqvist et al 455/525
5,740,165 A * 4/1998 Vannucci 370/330
5,774,790 A * 6/1998 Dupuy 455/33.1
5,781,540 A * 7/1998 Malcolm et al 370/321
5,812,545 A * 9/1998 Liebowitz et al 370/337
5,930,706 A * 7/1999 Raith 455/422
FOREIGN PATENT DOCUMENTS
EP 0 444 485 A2 2/1991
EP 0 637 895 A2 7/1994
GB 2284496 A 6/1995
GB 2299695 A 10/1996
* cited by examiner
Primary Examiner—Douglas Olms
Assistant Examiner—Bob A. Phunkulh
(74) Attorney, Agent, or Firm—Banner & Witcoff, Ltd.
(57) ABSTRACT
In a messaging system, message traffic is transmitted on one or more traffic channels T1; T2 and the allocation ol groups S1; S2 ol receivers to the traffic channels T1; T2 is controlled by information transmitted on a bulletin board channel BB. A predetermined number ol frames before a change in the traffic channel allocation, a countdown value is transmitted in the relevant traffic channel T1 and the countdown value is decremented in each subsequent frame. Before the countdown value reaches zero, the groups ol receivers S1; S2 retune to the bulletin board channel, receive their new channel allocations and retune to the traffic channel indicated for their group. The frame timings ol the different traffic channels Tu T2 are staggered to reduce the peak power required to transmit message bursts in these channels.
30 Claims, 8 Drawing Sheets
