- Acquisition of telemetry data from radio-tagged whales. A New Networking Model for Biological Applications of Ad Hoc Sensor Networks - Acquisition of telemetry data from radio-tagged whales.

Requirement Whale Behavior has to be monitored. Whales data - body temperature, heartbeat, and diving depth. Environmental data - illumination level, temperature, and salinity of the water. Data need to be recovered from the tags and delivered to the marine biologists

Solution Overview Miniature electronic sensing and transmitting tags are implanted into whales. Radio tags of a Shared Wireless Infostation Model (SWIM) network form a partially-connected network Data stored in time-stamped packets that can be copied between nodes. CS collects the data from tag and transmits it to BS

Problem lifetime of a packet depends on the mobility patterns of the whales mobility pattern specific to the whale species. Daily surfacing near collection stations for whales off the coast of the Hawaiian islands. Migratory whales visit known feeding grounds twice a year Spreading packets to other nodes consumes network resources - capacity and storage.

Problem Solution Allowing copies of the packet to be stored within mobile nodes. Replicas reaching the CS Time - reduced. schemes used to discard obsolete packets high probability that the info has been offloaded retain the identifier of the packet that it offloaded

Design Overview Data collected on a whale tag is stored locally. Whales in close proximity - stored information transmitted with some “Transmission probability” whale surfaces and comes in contact with collection stations, offloads all the data. Placing collection stations close to feeding areas – high data-rate for longer periods.

Continued … Meet the delay requirement - several CS should be placed within the habitat. Collection stations transmit the information to shore By coordination with other collection stations directly to a satellite that passes overhead. Mobile Collection stations placed on seabirds, flying high above the water. data gathered from the mobile collection stations at roosting grounds seabirds.

Collection stations Comparison Effect of different CS arrangements on the cumulative distribution F(T). Cumulative distribution curves with varying speeds of the mobile CS.

Packet Discarding Strategies (PSD) FULL_ERASE - After offloaded to a CS - discards the packet copy completely. IMMUNE method - discards the packet after offloaded - keeps Pkt identifier. IMMUNE_TX - discards the packet after offloading, keeping the antipacket, it shares the antipacket with other whales that carry copies of that packet. VACCINE - shares all of the packets and the antipackets, whether the packet is stored at the receiving whale or not.

PSD Comparison Expected storage required for 10 whales, varying probability of delivery and indicating corresponding expiration times. Storage–delay trade off of SWIM using the different methods of discarding packets.

SWIM vs Infostation Model

Conclusion Sharing reduces the delay by a factor of 4.6 compared to the non-sharing case. Using VACCINE method, delay reduction achieved with meanstorage increase of only 14% compared to the non-sharing case. In many cases it significantly reduce delay of data acquisition with only a moderate increase in storage requirements.

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