Solution of the Hidden Terminal Problem using Random Length Signals for Wireless LANs

The hidden terminal problem is a big problem when we use a wireless LAN. To solve that problem, IEEE 802.11 employs the RTS/CTS scheme which informs, before packet transmission, existence of a sending terminal to the neighbors of the sender and the receiver. However, when offered load increases, collisions of RTS frames also increase and they cause performance degradation. In this paper, we replace an RTS frame with a random length jam signal which does not have any information. The proposed scheme gives a transmission privilege to the terminal which lastly completes the jam signal. Thus the terminal can proceed to the next stage, packet transmission, even if its jam signal is collided. The simulation results show that our scheme improves throughput in comparison with the RTS/CTS scheme.