DSC with Slotted ALOHA Random Access n Distributed

DSC with Slotted ALOHA Random Access n Distributed source coding (DSC) X Y n Encoder 1 Joint Decoder Encoder 2 We study the effect of MACs on the efficiency (delivery success rate ) and delay of DSC-based sensor network : Sensor Success Rate = Number of reconstructed packets N : cluster head p 1 Node 1 2 X, Y n np 2 p 3 3 p. N N Delay : the average number of time slots needed to reconstruct

Energy Consumption Analysis n Energy consumption for slotted ALOHA in a DSC-based WSN has been analyzed in two point-of-views: n n n pi Average energy consumed to resolve at least n packets Average energy consumption after m slots transmissions Comparisons are made among transmission schemes with different transmit probability sets { p 1 , p 2 , … , p. N } Scheme 1 Node i pi Scheme 2 Node i pi Scheme 3 Node i

Simulation Model for H (Xi | Xi-1 , …, X 1) n Consider {Xi} as a 1 -D continuous-space-parameter stationary Gaussian-Markov process [1] with n n n Zero mean, variance σ 2 Autocorrelation : R (τ) = σ 2 e – |τ| (τ is a distance factor) Based on above model, the conditional entropy is given as [1] n E. g. , for σ= 1,

Average Entropy Transmitted vs. Time Slots 350 300 Entropy 250 200 150 100 Scheme 1 Scheme 2 Scheme 3 50 0 0 50 100 150 200 250 300 Time Slot 350 400 450 500

Reference [1] D. Marco and D. L. Neuhoff, “Reliability vs. efficiency in distributed source coding for field-gathering sensor networks, ” IPSN 2004, pp. 161 -168.