Distributed reservation CDMA for wireless LAN

Recent technology innovations have increased the interest of end-user in wireless LAN (local area networks). However, conventional access protocols have some problems such as degradation of channel utilization, necessity of control station and code reuse. Therefore, we propose new multiple access schemes, 'distributed reservation CDMA with priority (DR CDMA P)' and 'distributed reservation CDMA without priority (DR CDMA NP)', that can solve those problems in a distributed CDMA wireless LAN environment. Simulation results show reliable performance improvement by the new proposed protocols in a wireless LAN environment that has a large bandwidth and many nodes. This performance improvement is due to the variable length transmission property, minimum guard time and preamble, and optimal channel utilization of reservation CDMA. Also, DR CDMA P transmits data effectively when the offered load increases over 1 due to the effective control mechanism, although reservation TDMA and DR CDMA NP cannot transmit data due to an extreme delay in the heavy load condition. In the view of management, insertion of new node and extension problems can be easily solved in proposed reservation CDMA protocols. Also, the new protocols can provide a high degree of security readily due to the spread spectrum property. Especially, inter-networking with conventional protocols, such as IEEE 802.3 Ethernet, is simple without additional overhead because of the variable length property.