Geography-informed Energy Conservation for Ad Hoc Routing Ya Xu, John Heidemann, Deborah Estrin ISI...
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Transcript of Geography-informed Energy Conservation for Ad Hoc Routing Ya Xu, John Heidemann, Deborah Estrin ISI...
Geography-informed Energy Conservation for Ad Hoc Routing
Ya Xu, John Heidemann, Deborah Estrin
ISI & UCLA
Presented by: Cristian Borcea
Solution
identifies equivalent nodes for routing
based on location information
turns off unnecessary nodes
Assumptions
dense node deployment
many nodes can hear each other
each node knows its location
GPS ... but better other methods
Energy Model
listen:receive:transmit energy consumption 1:1.05:1.4 or 1:1.2:1.7
recall from last week listen:receive:transmit times are 1:3:40
duty cycle > 22% ==> more than 50% of energy spent in listening
energy dissipation in idle state cannot be ignored
Determining Node Equivalence
the physical space is divided into equal size squares based on nominal radio range
any two nodes in adjacent squares can communicate with each other
the nodes within a square are equivalent
Geographical Adaptive Fidelity ( GAF ) Routing
nodes in the same grid coordinate each
other
who will sleep and for how long
runs over any ad hoc routing protocol
load balancing energy usage
all nodes remain up for us long as possible
Node Ranking
node(active) > node(discovery)
enat1>enat2 ==> node(enat1)>
node(enat2)
enat = estimated node active time
node ids break the ties
Adapting to Mobility
each node estimates the time when it expects the leave the grid: engt
includes this estimation in the discovery message other nodes sleep for min(enat, engt)
GAF-ma ( mobility adaptation ), GAF-b ( basic scheme )
Simulation
ns2 + cmu's extension for 802.11 AODV vs GAF/AODV DSR vs GAF/DSR 50 transit nodes ( "routers" ) 10 traffic nodes ( sources & sinks ) Traffic: CBR Nominal radio range: 250
Energy model - values used in simulation
WaveLAN (pre-802.11, 1995) 2Mb/s listen:receive:transmit 1:1.2:1.6W
0.025 when sleeping 802.11 wireless LAN
0.75:1.5:1.9W 802.11 cards
0.83:1:1.4W
GAF energy savings
mean energy consumption per node (E0-
Et)/(n*t)
E0 initial total energy for n nodes
Et total energy after time t
results: GAF+AODV is 40% better than AODV
for both GAF-b, GAF-ma