02.563GPPGSM Cordless Telephony System (CTS), Phase 1Service descriptionStage 1TS

Today, there exists a clear distinction between the public mobile telephone systems for wide area coverage on the one hand, and private cordless telephone systems for local area coverage on the other hand. Recently, attempts have been made to integrate the wide area cellular and the local area cordless function into one and the same Mobile Equipment (ME). However, because of the incompatibility between the existing cellular and cordless standards, this results in ME implementations with rather low cost-efficiency.

The intention of the GSM Cordless Telephony System (CTS) is therefore to provide cordless functionality to a standard GSM Mobile Station (MS) with minimum impact on the MS. The impact would ideally be limited to an upgrade of the ME and SIM software. This can only be accomplished if the radio interface of the cordless system is identical, or very similar, to the standard GSM radio interface.