Unformatted text preview: oming messages between two active states are buffered An Adaptive Energy-Efficient MAC Protocol for Wireless Sensor Networks [Van dam+, 2003] The buffer capacity determines an upper bound on the maximum frame time Frame synchronization in T-MAC follows the scheme of virtual clustering as in S-MAC The RTS transmission in T-MAC starts by waiting and listening for a random time within a fixed contention interval at the beginning of the each active state The TA time is obtained using TA > C + R + T T-MAC suffers from early sleeping problem Its overcome by sending Future request to send or taking priority on full buffers An Adaptive Energy-Efficient MAC Protocol for Wireless Sensor Networks [Van dam+, 2003]
Advantages: The T-MAC protocol is designed particularly for wireless sensor networks and hence energy consumption constraints are taken into account The T-MAC protocol tries to reduce idle listening by transmitting all messages in bursts of variable lengths and sleeping between burst T-MAC facilitates collision avoidance and overhearing -- nodes transmit their data in a single burst and thus do not require additional RTS/CTS control packets. By stressing on RTS retries, T-MAC gives the receiving nodes enough chance to listen and reply before it actually goes to sleep -- this increases the throughput in the long run An Adaptive Energy-Efficient MAC Protocol for Wireless Sensor Networks [Van dam+, 2003]
Disadvantages: The authors do not outline how a sender node would sense a FRTS packet and enable it to send a DS packet Also sending a DS packet increases the overhead. The network topology in the simulation considers that the locations of the nodes are known T-MAC has been observed to hav...
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- Spring '08