The pan-European GSM signalling requirements for the Abis interface

The introduced global system for mobile communications (GSM) is implemented from design principles based on time division multiple access and frequency division multiple access with signalling control achieved by a combination of the integrated services digital network (ISDN) and common channel signalling CCITT No.7 (SS7) standards. This paper examines and presents measurements of the signalling attributes at the air and Abis interfaces within the GSM network. The transfer of information over the interfaces is controlled by the use of the GSM implementation of the ISDN and SS7 standards. A network model, consisting of a base station, a mobile unit and appropriate measuring instrumentation, is used representing the activity of both the air and Abis interfaces. A call is made and the performance of the associated signalling is analysed. The results show the different measurements of signalling in the GSM system for various conditions. The modifications to the Abis interface for GSM signalling in order to conform to ISDN and CCITT No.7 standards are also presented