Object extraction scheme and protocol for energy efficient image communication over wireless sensor networks

To date, wireless sensor networks lack the most powerful human sense - vision. This is largely due to two main problems: (1) available wireless sensor nodes lack the processing capability and energy resource required to efficiently process and communicate large volume of image data and (2) the available protocols do not provide the queue control and error detection capabilities required to reduce packet error rate and retransmissions to a level suitable for wireless sensor networks. This paper presents an innovative architecture for object extraction and a robust application-layer protocol for energy efficient image communication over wireless sensor networks. The protocol incorporates packet queue control mechanism with built-in CRC to reduce packet error rate and thereby increase data throughput. Unlike other image transmission protocols, the proposed protocol offers flexibility to adjust the image packet size based on link conditions. The proposed processing architecture achieves high speed object extraction with minimum hardware requirement and low power consumption. The system was successfully designed and implemented on FPGA. Experimental results obtained from a network of sensor nodes utilizing the proposed architecture and the application-layer protocol reveal that this novel approach is suitable for effectively communicating multimedia data over wireless sensor networks.