[Nets-seminars] EE Seminar 14th March 2014

[Richard G. Clegg]

Don't forget this Friday's seminar (14th March), the final one of term.  
The speaker is George Smart from UCL Electronic Engineering. The talk 
will be at 16:00 in GS/102 66-72 Gower Street.

Talk Title:    Decentralized Time-Synchronized Channel Swapping for 
Wireless Sensor Networks

Abstract:    Time-synchronized channel hopping (TSCH) is currently the 
most efficient solution for collision-free, interference-avoiding 
communications in wireless sensor networks (WSNs). However, all variants 
of TSCH require some form of centralized coordination to maintain the 
time-frequency slotting mechanism, which leads to slow convergence to 
steady state and moderate time-frequency slot utilization. We propose 
decentralized time-synchronized channel swapping (DT-SCS), a novel 
protocol for the medium access control (MAC) layer of IEEE802.15.4-based 
WSNs. Under the proposed DT-SCS protocol, wireless nodes first converge 
to synchronous beacon packet transmissions across all IEEE802.15.4 
channels with balanced number of nodes in each channel. This is achieved 
by reactive listening mechanisms, based on pulse coupled oscillator 
techniques at the MAC. Peer-to-peer channel swapping can then take 
place, via swap requests and acknowledgments made by concurrent 
transmitters in neighboring channels. We compare our DT-SCS protocol 
against TSCH in terms of convergence time, bandwidth utilization, 
connectivity and robustness to packet losses via simulations. In 
addition, the energy consumption of DT-SCS is reported via a 
Contiki-based deployment on TelosB motes. The results reveal that DT-SCS 
comprises an excellent candidate for completely decentralized MAC-layer 
coordination in WSNs by providing for quick convergence to steady state, 
high bandwidth utilization, high connectivity and robustness to 
interference and hidden nodes.


-- 
Richard G. Clegg,
Dept of Elec. Eng.,
University College London
http://www.richardclegg.org/