Development of Multi Channel Ad-Hoc Network System

This paper proposes a new Ad-Hoc network system which comprises the multiple relay access points (APs) with multi channels. AdHoc network systems are recently proposed and incorporated for the communication infrastructure, which relays wireless transmission among access points (APs) in wireless LAN (WLAN) system. System throughput is decreased due to hidden terminal problem when only a single channel is used for the Ad-Hoc network. In order to solve this problem, a new system with multi channels is proposed. However, even if the multi channels are employed, the coand/or adjacent-channel interference occurs due to hidden terminal problem and multiple APs in a limited space, when considering a simultaneous transmit and reception at the relay AP. In this paper, we develop an Ad-Hoc network testbed which can reduce and avoid coand/or adjacent-channel interference by using vertically arranged antenna configuration and distributed channel allocation scheme. Moreover, the effectiveness of our testbed is clarified by applying actual WLAN signals. key words: ad-hoc networks, vertical antenna arrangement, distributed channel allocation, multi channels