Portable communications and data terminal operating to optimize receipt of both incoming CDPD and AMPS messages
First Claim
1. A method of affecting handoff of a wireless subscriber station from a first cell to a second cell in a Cellular Digital Packet Data (CDPD) system, where said wireless subscriber station contains a first cell transfer database pertaining to radio frequency characteristics of said first cell, said method comprising steps of:
- (a) sending a polling receiver ready (RR) signal from said wireless subscriber station to a CDPD Mobile Data Base Station (NDBS) in said second cell;
(b) determining a first time interval for a complete Received Signal Strength Indication (RSSI) scan of said second cell by said wireless subscriber station;
(c) dividing said first time interval into a plurality of sequential overlapping time slots;
(d) alternately scanning said CDPD channel and an Advanced Mobile Phone Service (AMPS) control channel during successive time slots, thereby creating a second cell transfer data base transfer data base pertaining to said second cell; and
(e) deleting said first cell transfer database upon acquisition of said second cell transfer database.
0 Assignments
0 Petitions
Accused Products
Abstract
A portable radio telephone handset operates as a data transfer terminal as well as an analog cellular telephone subscriber station. Two modes of operation, an analog cellular communication mode and a Cellular Digital Packet Data (CDPD) mode, are available in the handset. The handset distinguishes between paging signals indicating CDPD mode communications and those indicating analog cellular communications. The handset also automatically preempts CDPD communications in favor of analog cellular communications such as those carried out in an AMPS configuration. The handset maintains an active status on a CDPD communication channel during a "sleep mode", when the handset can carry out AMPS activity.
82 Citations
9 Claims
-
1. A method of affecting handoff of a wireless subscriber station from a first cell to a second cell in a Cellular Digital Packet Data (CDPD) system, where said wireless subscriber station contains a first cell transfer database pertaining to radio frequency characteristics of said first cell, said method comprising steps of:
-
(a) sending a polling receiver ready (RR) signal from said wireless subscriber station to a CDPD Mobile Data Base Station (NDBS) in said second cell; (b) determining a first time interval for a complete Received Signal Strength Indication (RSSI) scan of said second cell by said wireless subscriber station; (c) dividing said first time interval into a plurality of sequential overlapping time slots; (d) alternately scanning said CDPD channel and an Advanced Mobile Phone Service (AMPS) control channel during successive time slots, thereby creating a second cell transfer data base transfer data base pertaining to said second cell; and (e) deleting said first cell transfer database upon acquisition of said second cell transfer database. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification