ad hoc network
DESCRIPTION
Ad hoc Network. 江崎研究室 修士1年 中島 亮. What is Ad hoc Network?. Meaning of Ad hoc Network Ad hoc =その場限りの Node to node → ノード間で一時的に形成されるネットワーク. Use of Ad hoc Network. Sensor network IC chip Weather sensor Sensor for scout Mobile network Cellular phone Note PC PDA - PowerPoint PPT PresentationTRANSCRIPT
Ad hoc Network
江崎研究室 修士1年中島 亮
What is Ad hoc Network?
Meaning of Ad hoc Network Ad hoc=その場限りの Node to node
→ノード間で一時的に形成されるネットワーク
A B
C
Communicate with A… I can!!
Use of Ad hoc Network
Sensor network IC chip Weather sensor Sensor for scout
Mobile network Cellular phone Note PC PDA→movable and weak computation and
battery power
Packet transferring
Multi-hop between nodes Efficient packet routing
→need to find efficient route
Efficient route
Multi-hop transferring
Getting routing information Pro-active
Making routing table beforehand Smaller lookup delay but more
communication Ex. OLSR, TBRPF
Re-active Look up route when needed Bigger delay but fewer communication Ex. DSR, AODV
OLSR
Optimized Link State Routing Hello message
One hop to all neighbor nodes Never forward (IP TTL=1) Message: own and neighbor’s address
HELLO MESSAGE
Feature of OLSR
MPR( Multi-Point Relay ) Smallest set of 1 hop nodes that can join all 2 hop
neighbor nodes Efficient flooding
Pink object in right picture is MPR
Getting topology
TC( topology control ) message All nodes selected as MPR MUST send Contain links between MPR and the node which s
elect the node as MPR Broadcast to all nodes Each nodes calculate topology and route from thi
s TC message and HELLO message
DSR
Dynamic Source Routing Route discovery
Efficient flooding by sequence number Relay node cache route information too
Request Reply
Feature of DSR
Route is written in Packet No loop can occur Confirm connection: use wireless ack
S
B
H
G
F
C
S-A-B-D
S-A-B-D
S-A-B-D
A
E
ID
Source Node
Destination Node
AODV
Ad hoc On-demand Distance Vector Re-active but partly pro-active
Search route when needed Same as DSR
Each node cache route from forwarding packet
Can use the same Hello Message as OLSR use To confirm links to neighbors are alive
Feature of AODV
Distance Vector (DV) Routing table
Destination node’s address Hop number to Destination node Next node to Destination node
Smaller packet Route is not in the packet
Smaller routing table Each node know only next hop node
Distance Vector
Conclusion
Outline of ad hoc network Behavior of OLSR, DSR, AODV Advantages and Disadvantages
OLSR:smaller delay,bigger communication Have way to lessen communication
DSR:bigger delay,smaller communication Have way to lessen delay
→Choose protocol as the situation demands