Mobile Wireless System Interworking with 3G and Packet Aggregation for Wireless LAN

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Virginia Tech

This research considered the efficient transmission of data within a wireless local area network (WLAN) system. A simulation model was developed to study the performance of our protocol, AGG-MAC (aggregated medium access control). AGG-MAC is a simple and elegant medium access control (MAC) protocol designed to improve performance by transmitting a maximal quantity of data with minimal overhead. Our enhancement to IEEE 802.11, AGG-MAC yields dramatic improvements in both local and global throughput. It furthermore reduces jitter in support of real time communications requirements such as voice over IP (VoIP). In support of heterogeneous roaming between Third Generation (3G) Wideband CDMA (WCDMA), specifically Universal Mobile Telecommunications System (UMTS) and WLAN systems, we constructed a simulation environment which allowed the evaluation of AGG-MAC in such a system. We further demonstrated the suitability of AGG-MAC throughout a range of infrastructure and ad hoc based WLAN scenarios. The AGG-MAC protocol enhancement provides significant performance improvements across a range of wireless applications, while interoperating with standard IEEE 802.11 stations. Performance is commensurate to original WLAN MAC performance for applications that do not benefit from packet level aggregation.

The key contributions of this research were two-fold. First was the development of an OPNET simulation environment suitable for evaluation of future protocols supporting tightly coupled, heterogeneous WLAN and 3G systems. Secondly was the implementation and testing of the AGG-MAC protocol which aggregates suboptimal size packets together into a single frame, thereby amortizing the overhead.

Protocol, UMTS, 3G, Aggregation, WLAN