Fault-tolerant algorithm based on multi-resolution of haar wavelets in opportunistic networks

A fault-tolerant algorithm based on multi-resolution haar wavelets was proposed to deal with the problem of concentrated data packets lost in opportunistic networks. The basic idea of algorithm can be described as follows. First, the signals are decomposed by wavelet transformation to get the low-frequency coefficients and high-frequency coefficients before it is sent. The ARQ mechanism is used to transfer the low-frequency coefficients. The high-frequency is transferred directly. Then, the signals are restored based on conversation of energy in the receiver. Theoretic analysis and simulation results show that the proposed algorithm can efficiently recover the original signal and maintain good fault-tolerant performance even continuous packets lost because of the bad disturbance.