Analytical framework for simultaneous MAC packet transmission in a multi-code CDMA wireless system

Stabilizing the throughput over wireless links is one of the key challenges in providing high-quality wireless multimedia services. Wireless links are typically stabilized by a combination of link-layer Automatic Repeat reQuest (ARQ) mechanisms in conjunction with Forward Error Correction (FEC) and other physical layer techniques. A novel class of ARQ mechanisms, referred to as Simultaneous MAC Packet Transmission (SMPT) was proposed recently. SMPT stabilizes the wireless link by transmitting multiple packets in parallel in response to packet drops due to wireless errors. The initial simulation results demonstrated a significant improvement in the link-layer throughput, however, increasing the interference level in a given cell.; The goal of this dissertation was to develop an analytical framework to evaluate the performance of wireless terminals (clients) employing some sort of SMPT mechanisms. In particular, this work focuses on the link-layer buffer occupancy and the interference caused by each of the client to other users. The analysis quantifies the trade off between increased link-layer quality of service and reduced number of supported flows (caused by the increased interference) in SMPT with good accuracy, as verified by simulations. This dissertation investigates two different frameworks. The first framework captures the dynamics of a system comprised of clients with independent (Bernoulli) packet arrivals. This framework, however, fails when the clients have bursty packet arrival processes, which is often encountered in real networks. The second framework is more generalized which accommodates both kind of clients, those that have independent packet arrivals and those that have bursty packet arrivals. It expresses the system dynamics as transition probabilities for a Markov chain and calculates the effects of the interference through an iterative approach.; The numerical results from both the analytical frameworks and verifying simulations indicate that SMPT provides a significant reduction in packet losses and buffer occupancies (and delay) in certain scenarios (such as persistent traffic bursts, highly active clients) in exchange for a reduced number of support flows. The analytical frameworks developed in this work quantify these system trade-offs with good accuracy and can thus be employed for resource management.