Method of handing off and a wireless communication device

• US 5,987,012 A
• Filed: 12/19/1996
• Issued: 11/16/1999
• Est. Priority Date: 12/19/1996
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Vilmur, Richard J., Bruckert, Eugene J.
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Nguyen, Kim T.
• Application Number:
  US08/769,562
• Time in Patent Office: 1,062 Days
• Field of Search: 370/331, 370/332, 370/335, 370/342, 375/200, 455/442
• US Class Current: 370/331
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/302 due to low signal strength

Abstract

A wireless communication device (100) can be handed off while operating in the slotted mode of a CDMA system. The wireless communication device (100) stores, prior to entering slotted mode, an Active Set including at least one active pilot and a Neighbor Set including a plurality of neighbor pilots. At least one receiver searcher (109) scans the at least one active pilot and at least one of the plurality of neighbor pilots prior to an assigned slot. A logic and control circuit (113) includes in the Active Set, prior to the assigned slot, at least two pilots of the at least one active pilot and the at least one of the plurality of neighbor pilots scanned prior the assigned slot. At least two of a plurality of receiver fingers (107) simultaneously monitor the Paging Channels of the at least two pilots during the assigned slot.

Claims

1. A method of autonomously handing off a wireless communication device operating in an idle state slotted mode to one or more of a plurality of base stations, the wireless communication device storing prior to entering slotted mode, an Active Set including at least one active pilot, a Neighbor Set including a plurality of neighbor pilots, and an assigned slot to monitor a Paging Channel therein, the wireless communication device includes at least one receiver searcher and a plurality of receiver fingers, the method comprising the steps of:

prior to the assigned slot;

a) determining a Hot Neighbor Set that includes a subset of the plurality of neighbor pilots, the subset of the plurality of neighbor pilots of the Hot Neighbor Set called hot neighbor pilots, and the neighbor pilots in the Neighbor Set but not in the Hot Neighbor Set called cold neighbor pilots;

b) assigning the at least one receiver searcher to scan the at least one active pilot and the at least one of the hot neighbor pilots;

c) scanning the at least one active pilot and the at least one of the hot neighbor pilots;

d) assigning at least two of a plurality of receiver fingers to monitor a plurality of Paging Channels of the base stations transmitting the at least two pilots of the scanned at least one active pilot and the at least one of the hot neighbor pilots;

e) assigning the at least one receiver searcher and the plurality of receiver fingers not assigned to monitor the plurality of Paging Channels to scan, as time permits during the assigned slot, the hot neighbor pilots that have not been scanned and then the cold neighbor pilots;

during the assigned slot;

f) simultaneously monitoring the plurality of Paging Channels of the base stations transmitting the at least two pilots;

g) scanning the hot neighbor pilots that have not been scanned prior to the assigned slot and then the cold neighbor pilots; and

after the assigned slot;

h) re-determining the Hot Neighbor Set according to the measured signal strengths of the at least one active pilot, the hot neighbor pilots, and the cold neighbor pilots.