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US006201968B1
(12) United States Patent ao) Patent No.: us 6,201,968 Bi
Ostroff et al. (45) Date of Patent: Mar. 13,2001
(54) METHOD COMBINING ENTRIES FROM
MULTIPLE NEIGHBOR CELL LISTS TO
OBTAIN AN UPDATED LIST FOR A
SUBSCRIBER DEVICE
(75) Inventors: Jeff L. Ostroff, Margate; Orestes G.
Melgarejo, Pembroke Pines; Steven S.
Alterman, Davie, all of FL (US)
(73) Assignee: Motorola, Inc., Schaumburg, IL (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/035,140
(22) Filed: Mar. 5, 1998
(51) Int. CI.7 H04Q 7/20; H04B 7/00
(52) U.S. CI 455/436; 455/437; 455/442;
455/443; 455/450; 455/509
(58) Field of Search 455/436, 437,
455/438, 439, 440, 441, 442, 443, 444, 422, 450, 451, 452, 453, 446, 456, 509, 512, 513, 514, 515; 370/329, 338, 331,
332
(56) References Cited
U.S. PATENT DOCUMENTS
5,222,248 6/1993 McDonald et al 455/33.2
5,260,943 11/1993 Comroe et al 370/95.1
5,276,906 1/1994 Felix 455/33.2
5,509,051 4/1996 Barnett et al 379/59
5,649,291 7/1997 Tayloe 370/332
5,649,303 7/1997 Hess et al 455/63
5,666,650 9/1997 Turcotte et al 370/329
5,673,307 9/1997 Holland et al 379/60
5,854,981 * 12/1998 Wallstedt et al 455/439
5,915,221 * 6/1999 Sawyer et al 455/437
5,946,621 * 8/1999 Chheda et al 455/440
* cited by examiner
Primary Examiner—Dwayne Bost
Assistant Examiner—Raymond B Persino
(74) Attorney, Agent, or Firm—Andrew S. Fuller
(57) ABSTRACT
A subscriber unit (405) operating within a radio communication system (600) supplements neighbor list information received from a cell site (428), when that cell site (428) is expected to provide inadequate neighbor cell list information. When the subscriber unit (405) obtains a new neighbor cell list (442) from the cell site (428), it determines whether characteristics of the cell site (428) is such that the new neighbor cell list (442) does not adequately reflect available neighboring cell sites. Such a condition is presumed to exist for a cell site designated as a high site. In such cases, the subscriber unit combines entries from its current neighbor cell list (451) with entries from the new neighbor cell list (442) obtained from the cell site to generate a supplemented neighbor cell list (652). The supplemented neighbor cell list (652) is used to monitor potential server sites, and to make hand-over decisions.
14 Claims, 6 Drawing Sheets
