Controlling power transmission settings within a second air interface based on inferred propagtion conditions from those assessed in a first air interface

摘要

A communication system (10, 68) includes a plurality of different, spectrally separated air-interfaces providing different services from co-located base sites (70-76). One of these air-interfaces, which may be CDMA, operates a universal frequency-re-use pattern across multiple cells (80, 88, 90), whereas other air-interfaces, such as GSM, have carrier frequencies that have a cell re-use pattern. A subscriber unit (12-16) within the system (10, 68) monitors an interference environment and path loss of at least some of the various different services to infer propagation conditions that are likely to be experienced within a spread spectrum service supported by the universal frequency re-use pattern. Armed with an assessment of a fade (82-86) condition within the system as a whole, implied by time and path loss from broadcast signals from different services, the subscriber unit can regulate and control its power transmission. Spread spectrum communication to a distant base station can be safe in the knowledge that high power transmissions from the subscriber are subject to deep fade when viewed by near-in base sites. Near-far problems associated with high power transmissions to near-in base sites can therefore be mitigated based on a level of confidence that is found in the fade condition determined by path loss in services ancillary to the spread spectrum service.