POWER CONTROL METHOD DURING CALL ESTABLISHMENT IN A RADIO COMMUNICATIONS SYSTEM

摘要

Upon call set-up requests in a CDMA-based communication system (1), an outer power control loop function is initially armed (158) with a time-averaged Eb/No value for a desired quality of service (QoS) of a specific service-type, e.g. voice, data or video, at a particular location. Clearly, different locations (Xn, Yn) within the communication system (10) are subject to different propagation environments and so the time-averaged Eb/No values (110) vary between services and locations. Generally, as exemplified in Fig 3, an RNC (36-40) is operable to maintain a continuously updated database (100) through recodal of converged outer loop targets (for a cell or georgraphic location) for each specific type of service. When a new call is initiated (150), an initial outer power control loop target is taken (110) to be the time-averaged Eb/No valude from the database (100). In this way, any transient period (160) between call establishment (150-158) and convergence to a true required outer loop threshold is reduced, increasing overall network quality and capacity. The initial default within the database (100) doe not need to be chosed with particular care since it will soon be updated once an associated Node B (26-31) goes live, tereby avoiding the necessity of having to extensively system test new Node B sites in an interference-critical radio environment. The process of updating location-specific converged Eb/No values may be maintained (168) in-call.