2. Video-Based Sensor Networks H. GHARAVI K. Ban NIST

3. Video-Based Sensor Networks zVideo streaming yRTP zNetworking yMulti-hop/Ad-hoc zTransport Systems yIEEE 802.11b xDSSS xFHSS zImplementations ySPW software implementation to evaluate the network deign yiPAQ based experimental setup for real-time demo

4. Multi-hop Sensor Networks Requirements; Energy efficient Scalable For an efficient and robust system IEEE 802.11 FHSS is considered.

5. Implementations & Demos SPW implementation of 801.11b FHSS xfor evaluating the performance of the physical layer under various mobility conditions. xreceiver design with Viterbi equalizer for 2GFSK, 4GFSK, and 8GFSK signals xAntenna Diversity xTransmission of video bitstreams xEffect of packet loss on the recovered video

6. Multi-hop ad-hoc Networks zAODV (Ad-hoc on-demand Distance Vector ) routing. zDSR (Dynamic Source Routing) zSensoria Multi-hop Network (WIN NG 2.0) zNIST Approach

7. AODV It provides loop free routes using sequence numbers associated to each route. AODV MODULES consists of: Rout request, rout reply, routing table, packet resend, packet capture S A B C D RREQ D X To B To C To D RREP S X REER

8. Sensor Ad-hoc Networking (NIST Demo) AP AP AP 802.11 b FHSS IP UDP RTP H.263 802.11 b FHSS IP UDP RTP H.263 AP Sensor Networks i P A Q iPAQ

9. Video Streaming yVIC/RTP package yVIC on iPAQ (Linux) yApplied H.263+ compression for low bitrate video conferencing yDeveloped H.263 + -based Error resilient video decoding xPartitioned xNon-partitioned yRTP/UDP for low delay video conferencing

10. PLCP Hdr. 802.11 MAC FCS PLCP Preamble MPDU 802.2 LLC 802.2 SNAP UDP Hdr. RTP Hdr. IP Hdr. H.263 video stream Payload Hdr. Physical Layer Logical Link Layer Network Layer Transport Layer Frame Format for video stream transmitted by RTP/UDP/IP with IEEE 802.11

11. Solutions zDelivering corrupted packets to the higher layer. yPerform packet-loss corrections: xSuitable for multicast xUnsuitable for conferencing yPerform error resilient video decoding by taking advantage of the RTP packet sequencing to detect lost packets Parity check packet Data packet-k Data packet-1

12. Video Partitioning DataSplitterDataSplitter IEEE 802.11b FHSS FHSS DataAssem. H.263VideoEncoderH.263VideoEncoder R = Bitrate (fixed) S = Splitting Percentage Rate CODEC INDEPENDENT H.263VideoDecoderH.263VideoDecoder Packet-H + FEC1 Packet-L+FEC2 Delay MUX DEMUX FEC-2Decoded FEC-1Decoded Delay R.S R.(100-S)

13. Error Resilient H.263 video streaming (SPW Demo) H.263 + encoder Video Input H.263 + decoder IEEE 802.11b FHSS Bitstreamre-sync. Videostreaming H.263 encoder Video Input H.263 decoder IEEE- 802.11b FHSS Splitting&streaming Bitstream combine & re-sync.

14. Pre-Decoder Design (non-partitioned) videobitstream Bitstreamreconstruction ErrorConcealment Buffer HeaderExtractor Legal H.263 bitstream Errorclassifications SelfErrorDetection StandardVideoDecoderVideoDisplay

15. FY’02 tasks zComplete the 802.11b FHSS implementation for field tests zPerformance evaluations in terms of : Coverage (indoor/outdoor) Mobility Bandwidth Number of nodes zFurther extensions to improve the error resilient decoding of the corrupted bitstream