Resource auction multiple access (RAMA) in the cellular environment

Resource auction multiple access (RAMA) is a technique for rapidly assigning communication resources (e.g., frequency carriers and/or TDMA time slots) in a wireless environment. This scheme is deterministic in that, barring errors caused by fading and noise, a resource assignment is made in each and every assignment cycle. Previous papers reported on the ultimate call assignment capacity of this technique, limited only by propagation delays, and also demonstrated its capabilities for statistical speech multiplexing in a PCS environment. We extend the previous work in two directions: (1) we examine the effects of channel fading and noise; and (2) we consider both GSM and IS-54 cellular environments. Propagation is modeled, for purposes of this study, as flat Rayleigh fading, with mean propagation loss as a parameter. We focus on the subscriber-to-base link and consider several forms of diversity at the base. We also consider two RAMA modes (call assignment without and with statistical speech multiplexing). We show that a simple form of two-branch diversity can be very effective. In both GSM and IS-54, for example, using simple diversity and an average transmit power of 100 mw yields assignment error probabilities of only 1% for losses as high as 151 dB