map based routing in large scale urban vehicle networks
Post on 24-Dec-2015
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AGENDA
Exploratory Research• Stable vs.
unstable• Transmission
collision
Optimal Algorithm• Two Variants• Inefficiency of
existing algorithms revealed
• Properties of Optimal Routing Path
Map Based Routing• Rationale• Implementation• Simulation
OPTIMAL ROUTING ALGORITHM
Minimum Delay Algorithm (MDA) Minimum Delay and Hops Algorithm (MDHA) Vehicular to Vehicular, Vehicular to Location, Location to
Location
INEFFICIENCY OF EXISTING ALGORITHMS REVEALED Geo routing family:
Performance degrades quickly as transmission distance increases Local maximum is extremely hard to detect
Mobility based routing family Is the behavior of individual node really RELAIBALY predictable? Choice of the length of time frame used in statistical pattern mining Let’s consider the JOINT probability
PROPERTIES OF OPTIMAL ROUTING PATH Relative spatial stability Relative temporal stability Routing sequence is very dynamic
MAP BASED ROUTING
Switch the respective
Dynamic network with vehicles being nodes
Static structure network with dynamic link weights
Item From To
node vehicles intersections
link contacts roads
Weighted by
Signal quality
Average packet travel time
MODEL FOR A ROAD SECTION
Modeled as a bi-directed link The weight of a link reflects the average packet travel
time over that link𝑃𝑎𝑐𝑘𝑒𝑡 𝑇𝑟𝑎𝑣𝑒𝑙 𝑇𝑖𝑚𝑒= Ϝቆσ𝑉𝑖𝑁 , 𝑁𝐿𝑟𝑜𝑎𝑑 ,𝐿𝑟𝑜𝑎𝑑 ,𝐷𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠ቇ+ ℇ
where 𝐿𝑟𝑜𝑎𝑑 ≡ 𝑙𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑡ℎ𝑒 𝑟𝑜𝑎𝑑 𝑠𝑒𝑐𝑡𝑖𝑜𝑛 σ𝑉𝑖𝑁 ≡ 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑣𝑒ℎ𝑖𝑐𝑙𝑒 𝑠𝑝𝑒𝑒𝑑
𝑁𝐿𝑟𝑜𝑎𝑑 ≡ 𝑙𝑖𝑛𝑒 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠 𝑜𝑛 𝑡ℎ𝑒 𝑟𝑜𝑎𝑑 𝑠𝑒𝑐𝑡𝑖𝑜𝑛
𝐷𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠 ≡ 𝑡ℎ𝑒 𝑑𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠 The bandwidth of the road section 𝐵𝑟𝑜𝑎𝑑 : 𝐵𝑟𝑜𝑎𝑑 = 𝐸 ۃ
1𝑃𝑇𝑇 ۄ
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