Method and apparatus for soft handoff communications in a communication system operating according to IS-95B and IS-95C standards
US6768908B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 2000 |
| Grant date | Jul 27, 2004 |
| Priority date | — |
| Expiry date | Apr 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W36/304
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus provide for soft handoff operation of at least a first signal transmitted according to a first communication standard (IS-95B) and a second signal transmitted according to a second communication standard (IS-95C). A mobile station (104) initially receives the first signal, detects presence of a pilot signal, measures pilot signal strength, transmits a pilot strength measurement message, fails to receive a handoff direction message after transmitting the pilot strength measurement message, searches for detecting presence of a broadcast control channel associated with the type IS-95C cell sites, measures a carrier to interference ratio of the broadcast control channel, compares the carrier to interference ratio to a threshold, if the carrier to interference ratio is above the threshold, initiates a second communication according to IS-95C standard, thus, allowing initiating a soft handoff operation by allowing the base sites to transmit information according to the IS-95B and IS-95C standards respectively via the first and second signals. MS 104 combines the first and second signals to take advantage of the soft hand-off operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.