GSM standards activity on location

This paper discusses location techniques in the context of the GSM cellular system and gives an overview, at the time of writing, of the status of GSM standards and likely outcomes of the standards process. The requirements for location services are presented, and a system architecture given. The methods being standardised in T1P1.5 are listed and compared: uplink time of arrival (TOA), mobile-assisted enhanced observed time difference (E-OTD) and assisted GPS (A-GPS), as well as some of their variants. The possible applicability of these methods to different market scenarios is also discussed.