The topic for this paper was developed in close consultation with current and future clients of the Pyramid Mobile Networks advisory service. It strives to address the relevant technological, tactical and strategic issues that participating actors in the shift from IS-136 time division multiplex access (Tdma) networks to a GSM/Gprs overlay face. Information was collected for this work through interviews and e-mail exchanges between global vendors and operators, as well as through review of trade and business journals. Vendors, operators and interested industry participants will benefit from this paper by its clear definition of the process, explicit understanding of the Tdma to GSM/Gprs overlay, and traffic buildup/coverage analysis of when the transition will occur.
