This chapter presents propagation measurements to study the performance of 802.11g networks and discusses the throughput performance of 802.11g in a typical office space. It explains the effect of line of sight blockage on 802.11g throughput in an obstructed office space. The chapter provides a simulation model for a typical 802.11g ad hoc network and validates 802.11g propagation measurement results. Among the various variants of 802.11 Wireless local area networks, 802.11g is one of the most popular technologies being used in home and office networks worldwide. The 802.11g wireless adapters were D-Link DWL-G132 cards with a power output of 15 dBm. The 802.11g infrastructure network simulation model was developed using the OPNET Modeler 14.0. All wireless stations communicate using identical half-duplex wireless radios based on the 802.11g Access point. The effect of increasing the number of wireless stations on mean packet delay and throughput of the 802.11g infrastructure network.