Capacity analysis for a hybrid indoor mobile communication system using cellular and ad-hoc modes

The authors have proposed a dual mode system for indoor mobile communication. Mobile terminals (MTs) in this system communicate with each other directly or via BSs. The former mode is regarded as ad-hoc mode and the latter, as cellular mode. The decision which mode to use is given at an MT comparing the received power level from its partner and a base station (BS). The sharing approaches of wireless resources, frequency and time, considered in the cellular structure having two tiers can be applied to this dual mode indoor system with substituting the concepts of communication modes for cellular tiers. Then the capacity can be derived. In this paper, the capacity tradeoffs between the cellular mode and the ad-hoc mode for orthogonal sharing and spread-spectrum (SS) sharing are presented.