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.