摘要 |
An integrated communication system supporting multiple TDMA or TDD communication protocols whereby both protocols are supported within the same geographic region. Each protocol defines time frames and/or time slots of a different duration, from which is derived a composite time frame having a predefined timing structure. A first base station unit communicates in a first set of time slots of the composite time frame according to a first TDMA or TDD protocol, and a second base station unit (which may be collocated with the first base station unit) communicates in a second set of time slots of the composite time frame according to a second TDMA or TDD protocol. Coordinating electronics (such as a GPS receiver in one or both base station units) are provided so as to prevent collisions between communications occurring between each base station unit and its respective users. In a particular embodiment, a first protocol is a GSM protocol, and a second protocol is a TDD protocol utilizing spread spectrum techniques. The TDD protocol is structured so that each time slot is twice the duration of a GSM time slot, and each time frame is four times the duration of a GSM time frame. The system may comprise a number of "stacked" base stations in a single cell, each operating over a different frequency or using different spreading codes.
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