The present document gives an overall description of the lower layers of the radio interface for GSM based Cordless Telephony Systems (GSM-CTS). The GSM-CTS system is intended to provide a cordless connection between the fixed network and GSM-based CTS Mobile Stations (CTS-MS) via a private CTS Fixed Part (CTS-FP). Stage 1 is an overall description, from the service subscribers and user's standpoint, that view the network as a single entity which provides service to the user. GSM 02.56 contains the CTS Stage 1 service description. GSM 03.56 is a Stage 2 document that describes the system architecture of the GSM Cordless Telephone Systems (GSM-CTS), i.e. the system elements, the system interfaces and the functional capabilities.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

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The main assumption behind the CTS work item and in particular the CTS radio interface, is that a modified single timeslot state of the art GSM-MS chipset could be used for a home base station, i.e. as a CTS-FP. The CTS radio interface has been designed to meet a requirement of low generated interference, either from the CTS to existing overlaying PLMNS, either from a CTS to another CTS. This requirement is achieved by the combined usage of the three concepts: beacon concept, AFA concept and TFH concept.