A New Energy Efficient Protocol for Minimizing Multi-Hop Latency in Wireless Sensor Networks
M. Dhanaraj, B.S.Manoj, C.Siva Ram Murthy From Indian Institute of Technology, Accepted by PERCOM 2005
Power Saving Strategies for MAC layer data transmission Basic:
Data transmit channel should always sleep, not just idle.
Use a control channel to “wake up” data channel
Compare to Real implementation: STEM PTW
Current Problems
Power saving MAC layer schemes can cause longer setup-time in multi-hop data transmission because of the dual frequency radio setup.
When the active time of each node is not synchronized, the wake up signal is transmitted continuously until it receives an ack.
Dual Frequency Radio Setup Tactive– Active time for control chann
el Tsleep– Sleep time for control channel Ttotal – Tactive + Tsleep
Tdata – Time for data transmission
Setup Time delay in multi-hop data transmission (Stem)
Pipelined Tone Wakeup Scheme During the node receives data,
the receiving node use TONE message to signal all its neighbors to wake up.
Pipelined Tone Wakeup Scheme Control channel wake up time is
very short (several ms)
LEEM – Author proposed approach Idea: Why don’t we just make a reservation for next hop?
What we need to do so A synchronized control channel
active time based on each node’s routing table
Information for other’s reservation Additional types of messages
RES – reservation request packet P-ACK – reservation success ACK N-ACK – reservation failure ACK
1 – Hop Ahead Reservation (1-HAR)
N – Hop Ahead Reservation (N-HAR
The number of hops is set by N = (Tactive + Tsleep)/Tdata
Simulation Status
Ttotal: 5s
Simulation Results(1/2)
Simulation Results(2/2)
