| 摘要 |
<p>Disclosed is a method and system for performing handoffs in a wireless communications network which incorporates Voice over Internet Protocol (VoIP) using shared supplemental spreading codes. In this method and system, a mobile station is assigned a first and second primary code and a first and second set of supplemental codes. The first primary and set of supplemental codes are associated with a first base station. The second primary and set of supplemental codes are associated with a second base station and assigned to the mobile station when the mobile station is entering into a handoff state. The first and second set of supplemental codes belong to a pool of shared supplemental codes associated with the first and second base stations, respectively. A specific supplemental code is assigned from each of the first and second sets of supplemental codes when a complete packet cannot be transmitted over a single transmission time interval on the first and second primary channels. Each of the specific supplemental codes must be currently available before it could be assigned. Mapping tables may be used to associate assigned specific supplemental code indicators to specific supplemental codes belonging to the first and second set of supplemental codes. The mapping tables may be Transport Combination Format (TFC) mapping tables, and the assigned specific supplemental code indicators may be Transport Combination Format Indicators (TFCI). A single TFCI or equivalent may be used to indicate a same or different supplemental code at each of the first and second base stations.</p> |
