Transcript Ad Hoc Routing Protocols

Bandwidth Management Framework
for
IP based Mobile Ad Hoc Networks
Khalid Iqbal (41152190)
Supervisor: Dr. Rajan Shankaran
ITEC810
June 05, 2009
Problem Statement
“Incorporating scalable bandwidth
management scheme in an IP based
mobile ad hoc network environment”
Mobile Ad Hoc Networks
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Agenda
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IP based Mobile Ad Hoc Network
MANET Applications
Quality of Service (QoS)
MANET Routing Protocols
QoS Models
Existing QoS models in MANET environment
QoS models designed for MANETs
Ad Hoc Extensions for ASAP
Mobile Ad Hoc Networks
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IP based Mobile Ad Hoc
Networks (MANET)
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Collection of wireless nodes
Connected through wireless links
Free to move, Self-configuring
No pre-existing infrastructure
Dynamic topology
Distributed operations
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IP based Mobile Ad Hoc
Networks (MANET)
Mobile Ad Hoc Networks
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MANET Applications
Military battlefield
 Commercial Level
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Disaster relief efforts (flood, earthquake)
Local Level
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Class room network
Home network
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Quality of Service (QoS)
Capability of a network to provide better services to
selected network traffic.
Need for QoS in MANETs:
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Bandwidth management
Resource management
Application requirements
Applications
QoS Requirements
Email, File Transfer
Very tolerant of delay: low
Real Audio
Very sensitive to delay: High
Streaming Video
Very sensitive to delay: High
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MANET Routing Protocols
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Proactive or Table-driven protocols
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Reactive or On-demand protocols
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Maintain routing information
Waste of bandwidth
Immediate availability of routing information
No routing table
Path calculation before transmission
Less overhead, slower
Hybrid protocols
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Combination of both
Zone organization
Within zone proactive scheme
Outside reactive scheme
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QoS Models
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Integrated Services (IntServ)
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Management and packet scheduling on a per flow
basis
Difficult and costly for the routers
Differentiated Services (DiffServ)
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QoS control on a service class basis
QoS is invoked on packet-by-packet basis
Feasible and cost-effective
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QoS Models
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Integrated Services (IntServ)
Mobile Ad Hoc Networks
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QoS Models (Cont.)
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Differentiated Services (DiffServ)
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Existing QoS models in MANET
environment (Limitations)
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IntServ in MANETs
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Scalability
Protocol phases
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Connection establishment, maintenance, teardown
DiffServ in MANETs
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SLA
 traffic conditioning rules, placed at the nodes
Ambiguous core network
Mobile Ad Hoc Networks
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QoS models for MANETs
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Flexible QoS Model for Mobile Ad Hoc
Network (FQMM)
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Hybrid per-flow and per-class provisioning
Nodes have dynamic role
FQMM Limitations
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Scalability problem
Fail to satisfy hard QoS requirements.
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QoS models for MANETs
(Cont.)
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Adaptive Reservation and Pre-allocation
QoS Architecture (ASAP)
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For Infrastructure based networks
Soft/Hard Reservation
QoS Monitoring
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Periodic investigation
more frequent monitoring, if the network is unstable
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Limitations of ASAP
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Flow Restoration Problem
 Flow restoration can be quite long
 Detecting a missing reservation.
Reverse Path Problem
 Outdated paths
 unsymmetrical paths
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Solutions to address ASAP
problems
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Local Repair
Dynamic Virtual Path
Flexible Timing Control
Congestion Control
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Solutions to address ASAP
problems (Cont..)
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Local Repair
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Flow path broken because of dynamic topology
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No QoS guarantee from broken point to destination
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Quick repairing mechanism
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local repair triggered by a soft reservation message
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Upon receiving a SR message, node reserves some
bandwidth
Dynamic Virtual Path
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Unsymmetrical routes
Mobile Ad Hoc Networks
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Solutions to address ASAP
problems (Cont..)
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Flexible Timing Control
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SR (Soft Reservation) sending interval and the soft
state time-out period.
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Stable network - Large SR interval
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Coherent; SR and soft state time-out period
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too large soft state time-out will keep reservations on
Mobile Ad Hoc Networks
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Solutions to address ASAP
problems (Cont..)
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Congestion Control
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Queue length is not a valid indication
Congestion detection by monitoring the wireless
channel
Approximation of the bandwidth usage
Increase or decrease transmission throughput
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