초록 ▼

In a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, mobile stations initially seek access to a selected one of two or more groups of common packet channels (CPCHs) serviced through a base station. A second order collision resolution phase, conducted between the bas

In a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, mobile stations initially seek access to a selected one of two or more groups of common packet channels (CPCHs) serviced through a base station. A second order collision resolution phase, conducted between the base stations and contending mobile stations, serves to allocate one or more available channels from the selected group of channels among the contending mobile stations. In the collision resolution phase, each mobile station randomly selects a collision detection (CD) signature and sends that signature in a CD preamble. For each available channel in the group, the base station assigns one of the mobile stations. For each assigned mobile station, the base station transmits a CD acknowledgement that corresponds to the CD preamble of the assigned mobile station and identifies the available channel assigned to that mobile station.

대표청구항 ▼

1. In a code-division-multiple-access (CDMA) system employing spread-spectrum modulation comprising a radio network controller, a plurality of base stations, each base station (BS) comprising a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of mobile stations, each

1. In a code-division-multiple-access (CDMA) system employing spread-spectrum modulation comprising a radio network controller, a plurality of base stations, each base station (BS) comprising a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of mobile stations, each mobile station (MS) comprising an MS-spread-spectrum transmitter and an MS-spread-spectrum receiver, a method comprising the steps of:transmitting from an MS-spread-spectrum transmitter of a first mobile station at least one access preamble comprising an access preamble signature corresponding to a group of common packet channel (CPCH) channels selected from a plurality of groups of CPCH channels; transmitting from an MS-spread-spectrum transmitter of a second mobile station at least one access preamble comprising said access preamble signature; receiving at the BS spread-spectrum receiver of one of the base stations at least one of the access preambles at a detectable-power level; responsive to receipt of the at least one access preamble at the detectable power level, transmitting an acknowledgment signal corresponding to the access preamble signature from the BS-spread-spectrum transmitter of the one base station; receiving the acknowledgment signal at the MS-spread-spectrum receiver of each of the first and second mobile stations; transmitting from the MS-spread-spectrum transmitter of the first mobile station a first collision detection preamble comprising a first collision detection signature; transmitting from the MS-spread-spectrum transmitter of the second mobile station a second collision detection preamble comprising a second collision detection signature; substantially concurrently receiving the first and second collision detection preambles at the BS spread-spectrum receiver of the one base station; identifying a first available CPCH channel among the selected group of CPCH channels; selecting the first mobile station for assignment of the identified CPCH channel; transmitting from the BS-spread-spectrum transmitter of the one base station a base station collision detection preamble, the base station collision detection preamble corresponding to the first collision detection preamble signature and to the identified CPCH channel; receiving the base station collision detection preamble at the MS-spread-spectrum receiver of the first mobile station; and transmitting from the MS-spread-spectrum transmitter. of the first mobile station a spread-spectrum signal comprising any of data and power control information, over the identified CPCH channel, responsive to the receipt of the base station collision detection preamble.