A Message Ferrying Approach for Data Delivery in Sparse Mobile Ad Hoc Networks Wenrui Zhao, Mostafa Ammar and Ellen Zegura College of Computing, Georgia Institute of Technology, Atlanta, Georgia MobiHoc 2004

Outline Introduction Overview of message ferrying Node-initiated message ferrying scheme Ferry-initiated message ferrying scheme Performance evaluation Conclusion

Introduction Mobile Ad Hoc Network (MANETS) Rapidly deployment Rapidly deployment Self-configuration Self-configurationApplication Battlefield Battlefield Disaster relief Disaster relief Wide area sensing and surveillance Wide area sensing and surveillance

Introduction -problem description Nodes are sparsely distributed such that network partitions can last for a significant period Goal Efficient data delivery in sparse mobile ad hoc networks

Introduction Mobility-based approaches Use short range communication Exploit node mobility to help deliver data Store-carry-forward paradigm Is suitable for delay tolerant applications Classified as Classified as Reactive scheme Proactive schemes Message ferrying (MF) scheme Message ferrying (MF) scheme

Overview of message ferrying Environment Sparse Mobile Ad Hoc Networks Location-awareness Device are classified as Device are classified as Message ferries Take responsibility of carrying messages among other nodes Regular nodes Are devices without such responsibility

Overview of message ferrying Message ferrying (MF) Proactive mobility-assisted approach Use message ferries to provide communication services for nodesApplication Crisis-driven Crisis-driven Battlefield and disaster Geography-driven Geography-driven Wide area sensing and surveillance Cost-driven Cost-driven Service-driven Service-driven

Node-initiated message ferrying scheme

Mode transition diagram for nodes

Node-initiated message ferrying scheme Node trajectory control t d : t d : the time slot in which the node is expected to meet the ferry after proactive movement α: α: the average time between a node’s visits to the ferry T : T : the message timeout value in slotsGoal Minimize message drops while reducing the negative impact of proactive movement Minimize message drops while reducing the negative impact of proactive movement the message generation rate during slot t node i’s own message drop rate during time slot t the drop rate in the ferry for destination i during slot t the message generation rate in node i the message arrival rate in the ferry for destination i

Node-initiated message ferrying scheme Control how much time a node is allowed for proactive movement

Node-initiated message ferrying scheme Ferry operation

Ferrying-initiated message ferrying scheme

Node operation

Ferrying-initiated message ferrying scheme Ferry operation

Ferrying-initiated message ferrying scheme Node notification control To control the transmission of notification messages To control the transmission of notification messages Message drops a node sends a request message to the ferry only when Eq. (1) is true Ferry location d f <αand α<R l d f <αand α<R l Energy consumption notification message rate (NMR) V i <λ notification message rate (NMR) V i <λ

Ferrying-initiated message ferrying scheme Notification message Notification message Service_Request message Eq.(1), d f <α, V i <λ Eq.(1), d f <α, V i <λ Location_Update message d n <R s, d f <R l, V i <λ d n <R s, d f <R l, V i <λ

Performance evaluation Use ns simulator Transmission range:250m Transmit power:0.282W 40 nodes Area:5000m*5000m Message size:500bytes Timeout value:8000sec Node Speed:5m/s Speed:5m/s Pause time:50sec Pause time:50sec Buffer size:400 messages Buffer size:400 messagesFerry Speed:15m/s Speed:15m/s

Performance evaluation

NIMF scheme under different WTP threshold Message delivery rate Message delivery rate

Performance evaluation NIMF scheme under different WTP threshold Delivered message per unit energy Delivered message per unit energy

Performance evaluation FIMF scheme under different NMR threshold Message delivery rate Message delivery rate

Performance evaluation FIMF scheme under different NMR threshold Delivered message per unit energy Delivered message per unit energy

Performance evaluation FIMF scheme under different transmission ranges Message delivery rate Message delivery rate

Conclusion We develop two variations of the MF scheme, depending on whether ferries or nodes initiate proactive movement The simulation results show that the MF approach is very efficient in both data delivery and energy consumption