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Location Updates For Efficient Location Updates For Efficient Routing In Ad Hoc NetworksRouting In Ad Hoc Networks
Location Updates For Efficient Location Updates For Efficient Routing In Ad Hoc NetworksRouting In Ad Hoc Networks
Adviser: Ho-Ting Wu & Kai-Wei KeAdviser: Ho-Ting Wu & Kai-Wei Ke Presenter: Chih-Hao TsengPresenter: Chih-Hao Tseng
Outline• Introduction• Classification of Routing
Algorithms• Location updates between
neighboring nodes• Location-based Routing Protocols• Performance Evaluation issues• Reference
Introduction (1/2)• In MANET node mobility, activity, and availability of
methods to determine absolute or relative coordinates of each node.
• Various approaches in literature are classified according to
some criteria. • Mobility is apparently a very difficult problem to handle
in ad hoc networks.• proposed solutions have significant drawbacks. • progress has been made on the routing with known
destination location, location updates issue to enable efficient routing requires further investigation.
Introduction(2/2)Qualitative Properties
Quantitative Metrics
★Distributed Operation.★ Loop-Freedom.★ Demand-based Operation.★ Sleep Period Operation.
★ Hop counts ★ End-to-end data delay.★ Average number of data bits transmitted per data bits delivered.
Outline• Introduction• Classification of Routing
Algorithms• Location updates between
neighboring nodes• Location-based Routing Protocols• Performance Evaluation issues• Reference
Demand-based operation
• Proactive-Maintain routing table when nodes move.
-Unacceptable overhead.-Memorized.
• Reactive-Designing routes when they are needed-Source-initiated on-demand routing strat
egy.- Not memorized
Distributed operation• Localized
-Forward the message based solely-Neighboring nodes may update each other
location when ever an edge is broken or created-Do not memorize past traffic at any node
• Non-Localized-Shortest weighted path algorithm-Each node only knows node connectivity with
its own zone-significant overhead when use broadcast to find
destination
Location information• Using Routing Table• To minimized energy required per
routing task• To maximize the number of
routing tasks that a network can perform
Single-path vs. multi-path strategies
• Single-path-Full message-Lack of guaranteed delivery
• Multi-path-Short message
-Consisting of several single-paths-Be regarded as flooding
Loop-freedom• The proofs are based on the observation that
distances of nodes toward destination are decreasing.
S
D
Memorization of past traffic
• To memorize previous best path for providing future path to the same destination
• Using Routing Table• Significant overhead• Needed to escape loops in
directional based methods
Outline• Introduction• Classification of Routing Algorithms• Location updates between neighbo
ring nodes• Location-based Routing Protocols• Performance Evaluation issues• Reference
A
B
A’
B’
R
R
A’=A+at
B’=B+bt
The time t when the connection will be lost can be estimated by solving quadratic equation R=|A’B’|=|B-A+(b-a)t|
a
b
Outline• Introduction• Classification of Routing
Algorithms• Location updates between
neighboring nodes• Location-based Routing Protocols• Performance Evaluation Issues• Reference
Location-based Routing Algorithm
Original• MFR• GEDIR• DIR• LAR• DREAM• GREEDY• GRID• SP• FZ • GREEDY• DFS
Extended• LAR1 、 LAR2• CH-MFR • Alternate MFR • Disjoint MFR• R-DIR • Alternate DIR • Disjoint DIR• f-DEDIR • 2-f-GEDIR• Alternate GEDIR • Disjoint GEDIR • VD-GREEDY• f-GEDIR• DGRP• DGRP_DL • DGRP_SDL
Request Zone Routing• Distance Routing Effect Algorithm
for Mobility (DREAM)• Location-Aided Routing scheme 1
(LAR-1)• Location-Aided Routing scheme 2
(LAR-2)
DREAM(1/3)• Proactive• Distribute, loop free, Multipath routing• Routing table• Distance effect• Mobility rate• S->D select one-hop neighbor• Data-header: qualified to receive and forward• ACK for D->S in the similar way backward
• Advantage:-Location table-loop-free
• Disadvantage-Overhead increase when network grows.Often use in smaller MANET
DREAM(3/3)
Doubling Circles routing
• Each node updates its location to all nodes located within circle of radii 2tP, t=1,2,3…
• A similar algorithm (ex: DIR method)• Using squares instead of circles• Additional sophisticated techniques
Quorum based Strategies
• To form quorums of size approximately n1/2.
• Each column serves as a quorum• Virtual Backbone is initiated and
maintained.
Home-agent Based Strategy
• This is router with additional functionality
• Located on home network of mobile node (MN)
• Forwards packets to appropriate network when MN is away
When MN is at home
Internet
Foreign Network140.124.40.x
Home Network140.124.30.xFA
140.124.40.1
CN
HA 140.124.30.1
MNHome IP: 140.124.30.5
When MN moves to a foreign network
Internet
Foreign Network140.124.40.x
Home Network140.124.30.x
Home IP: 140.124.30.5CoA: 140.124.40.1
FA140.124.40.1
CN
HA 140.124.30.1
Visitor list
Binding table
Registration Request
Registration Reply
Outline• Introduction• Classification of Routing
Algorithms• Location updates between
neighboring nodes• Location-based Routing Protocols• Performance Evaluation Issues• Reference
Performance Evaluation Issues
• Delivery rate• End-to-end data delay• Communication overhead• Performance on static networks• MAC layer considerations• Comparison with the shortest path algorithm• Generating sparse and dense graphs• Node mobility• Simulator
Outline• Introduction• Classification of Routing
Algorithms• Location updates between
neighboring nodes• Location-based Routing Protocols• Performance Evaluation Issues• Reference
Reference• I. Stojmenovic, “Location Updates for Efficient
Routing in Ad Hoc Networks, Handbook of Wireless Networks and Mobile Computing, Wiley, 2002, http://www.site. uottawa.ca/~ivan, pp. 451–71
• http://www.cs.ccu.edu.tw/~yschen/course/94-1/papers/21.ppt.
• Irene Hsu, PART 1. Introduction, 03. Wireless Internet, http://www.irene-hsu.idv.tw/NTUT
• Irene Hsu, PART 3. Introduction, 07. Routing Protocol with MANETs (part 2), http://www.irene-hsu.idv.tw/NTUT