Collision Avoidance Using WTRP-MAC Protocol for Clustered Wireless Sensor Network

In a clustered wireless sensor network, multiple accesses at a time lead to collision. This could cause retransmit of lost packets. It increases power consumption, decreases sensor lifetime and delay in packet transmission. Basically sensors are not always need to send data. Suppose if an event occurs, then every sensor automatically accesses their base station simultaneously. It causes multiple communications at a single time and leads to collision. To overcome this problem in a wireless sensor network our proposed Collision Free MAC protocol is used. Passing token to the cluster head makes a single data transmission at the time. All the cluster heads in the Wireless Sensor Network starts transmitting data only when it receives token from the Base Station. After completion of transmitting the packets, the token will be passed to its successor cluster head. The Token passing depends on two states (i) THT, (ii) TRT. In every cluster head the desired ‘Token Holding Time’ gives stipulative time to sending data. Single ‘Token Rotation Time’ must provide token to all cluster head in the Sensor Network at a point of time. This process reduces collision during data transmission. The simulation result gives our Collision Free MAC protocol reduces collision at multiple accesses through given time of data transmission.