Performance analysis of multi-code spread slotted ALOHA (MCSSA) system: finite and infinite population

In this paper, we present an analytical framework to investigate the dynamics of a family of medium access control (MAC) protocols which are governed by two distinct elements. The first element concerns the users´ random selection from a finite number of resources (i.e., channels or spread spectrum (SS) codes). The second element is the simultaneous transmission of users´ packets if the resources happen to be SS codes. These elements are realized through two stages of packet acquisition (Stage-I) and packet transmission (Stage-II). Our analytical model is properly constructed and adequately parameterized to reduce to the special cases: slotted ALOHA, multichannel slotted ALOHA, and CDMA. To assess the performance of the MCSSA protocol, we evaluate two commonly used performance metrics: average packet delay and throughput. To validate the Markov model (e.g., finite population case) developed in this paper, we also develop a Poisson model (e.g., infinite population case). Preliminary results indicate that, depending on the loading (e.g., high offered load level), the MCSSA protocol surpasses that of its CDMA counterpart