Ten lectures on wavelets
Adaptive protocols for information dissemination in wireless sensor networks
MobiCom '99 Proceedings of the 5th annual ACM/IEEE international conference on Mobile computing and networking
Next century challenges: scalable coordination in sensor networks
MobiCom '99 Proceedings of the 5th annual ACM/IEEE international conference on Mobile computing and networking
Physical layer driven protocol and algorithm design for energy-efficient wireless sensor networks
Proceedings of the 7th annual international conference on Mobile computing and networking
Wireless sensor networks for habitat monitoring
WSNA '02 Proceedings of the 1st ACM international workshop on Wireless sensor networks and applications
Lightweight time synchronization for sensor networks
WSNA '03 Proceedings of the 2nd ACM international conference on Wireless sensor networks and applications
Distributed source coding using syndromes (DISCUS): design and construction
IEEE Transactions on Information Theory
A new, fast, and efficient image codec based on set partitioning in hierarchical trees
IEEE Transactions on Circuits and Systems for Video Technology
Efficient indexing data structures for flash-based sensor devices
ACM Transactions on Storage (TOS)
Energy-efficient transmission of wavelet-based images in wireless sensor networks
Journal on Image and Video Processing
Energy-efficient image transmission in sensor networks
International Journal of Sensor Networks
Heavily Reducing WSNs' Energy Consumption by Employing Hardware-Based Compression
ADHOC-NOW '09 Proceedings of the 8th International Conference on Ad-Hoc, Mobile and Wireless Networks
Information Sciences: an International Journal
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In wireless sensor network applications, an event is observed by a group of spatially distributed sensors which collaborate to make decisions. Since there is limited bandwidth in wireless sensor networks, it is important to reduce data bits communicated among sensor nodes to meet the application performance requirements. It also saves node energy since less bits are communicated between nodes. An approach is to compress sensor data before transmissions to reduce energy as some loss is acceptable without affecting the results of applications. Data collected by sensors that are in close proximity exhibit spatial correlation, further, since the samples collected over time are from the same source(s) also show temporal correlation. We shall first review state-of-the-art results on compression and issues in deploying these techniques in wireless sensor networks. We then present a new data compression scheme, called ESPIHT, that exploits this spatio-temporal correlation present in sensor networks to reduce the amount of data bits transmitted in a collaborative signal processing application. The proposed ESPIHT seamlessly embeds a distributed source coding (DSC) scheme with a SPIHT based iterative set partitioning scheme to exploit both spatial and temporal correlation. Instead of being a generic compression scheme, ESPIHT is coupled with application on which it adapts to application fidelity requirement so that application level false alarm rate is kept low. We evaluated the proposed scheme using dataset from an acoustic sensor based ATR application on a network of iPAQs with Wireless LAN connection. Our results show that ESPIHT reduces data rate by a factor of 8 and maintains Signal-to-Noise Ratio (SNR) gain of 20dB or better. The coding/decoding processing is simple and takes on the order of 10 msec on iPAQs. It is superior to known schemes in terms of SNR gain as shown in the experimental study based on field data when the sampling rate is relatively high and the network is dense.