Hidden terminal jamming problems in IEEE 802.11 mobile ad hoc networks

This paper addresses experimental measurements from an IEEE 802.11 ad hoc network testbed, which indicate a strong signal strength dependence in the ability of a hidden terminal to gain access to the radio channel. We present analytical results investigating the `hidden terminal jamming' ability of the IEEE 802.11 DSSS physical layer. Results indicate that in a hidden terminal topology, the presence of an interfering transmission with a signal strength marginally greater than the transmission currently being received will result in an intolerable increase in BER, effectively jamming the ongoing transmission. These results confirm previous experimental measurements which show that after a number of MAC layer timeout/retransmission periods, the original (weaker) connection is effectively prevented from gaining access to the channel.