Mobile Intelligence

3.2 RELATED WORKS

The CSMA protocol as proposed in Ref. [7] and its susceptibility to the hidden terminal problem was noted in Ref. [8], where the authors proposed a solution called busy-tone multiple access (BTMA) protocol. To reduce the effect of hidden terminal problem, multiple access with collision avoidance (MACA) protocol was proposed in Ref. [1]. MACA uses RTS/CTS mechanism to avoid the hidden terminal problem, but does not include any positive acknowledgement to ensure the integrity of the DATA transmission. A positive acknowledgement scheme as added in the MACAW protocol [2]. The MACAW protocol also requires nodes to send a packet called DATA-send (DS) to indicate that a DATA packet transmission is about to begin; however, this mechanism is not part of the IEEE 802.11 standard, so it may not be compatible with the standard protocol. Ray et al. [5] noted that in a general multihop network, the RTS/CTS mechanism cannot completely eliminate DATA packet collisions due to the masked node problem. They also observed that it holds true even under idealized conditions such as negligible control packet size, negligible propagation delay, and identical interference and packet-sensing ranges. Nevertheless, the RTS/CTS mechanism greatly reduces the hidden terminal problem and is desirable to be deployed in general. Although in Ref. [9] blocking in wireless network has been discussed, but the severity of false blocking was first described in Ref. [5] work. Shigeyasu et al. [10] proposed ...