QOD ROUTING PROTOCOLS

Presented by :S.Aakasham, ME-CSE

PG Scholar (2013-2015)

SVS COLLEGE OF ENGINEERING,CBE-

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Outline

Introduction of QoS Literature survey Objective Algorithm Advantages Disadvantages References

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Introduction Of QoS

To find a QoS path between source and destination, Which satisfies The QoS requirements for each admitted connection and Optimizes the use of network resources

Quality encompasses the data loss, latency, jitter, efficient use of network resources,..

QoS mechanisms for unfairness: managing queuing behavior, shaping traffic, control admission, routing, …

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Challenges In QOS

Mobility

Dynamic changing topology

Bandwidth constrains

Energy constrains

Scalability

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QOD ROUTING PROTOCOL FOR HWN

Usually, a hybrid network has widespread base stations

The data transmission in hybrid networks has two features:

1. An AP can be a source or a destination to any mobile node It allows a stream to have anycast transmission along multiple

transmission paths to its destination through base stations

2. The number of transmission hops between a mobile node and an AP is small It enables a source node to connect to an AP through an intermediate

node

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Network model of the HWM

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Algorithms

In this paper introduce the QoS-Oriented Distributed routing protocol(QOD)

This QOD protocol makes five contributions:

QoS-guaranteed neighbor selection algorithm

Distributed packet scheduling algorithm

Mobility-based segment resizing algorithm

Soft-deadline based forwarding scheduling algorithm

Data redundancy elimination based transmission

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Algorithm(cont..)

1.QoS-guaranteed neighbor selection algorithm The algorithm selects qualified neighbors and deadline-driven scheduling

mechanism to guarantee QoS routing Get an allocation set A :

Uas(i)* Wi : available workload rate source node needs to distribute its packets to the Nq

Ai : workload rate allocation from source node to immediate node Wg : the packet generating rate of the source node

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Algorithm(cont..)

2.Distributed packet scheduling algorithm After qualified neighbors are identified, this algorithm schedules packet

routing. It assigns earlier generated packets to forwarders with higher queuing delays, while assigns more recently generated packets to forwarders with lower queuing delays to reduce total transmission delay

Distributed queuing mechanism (e.g.: 3 packets distributed)

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Algorithm(cont..)

2.Distributed packet scheduling algorithm The queuing time of a packet with priority x estimated by :

and : The transmission delay and arrival interval of a packet

with the jth priority

: The number of packets arriving during the packet’s

queuing time

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Algorithm(cont..)

3.Mobility-based segment resizing algorithm The source node adaptively resizes each packet in its packet stream for each

neighbor node according to the neighbor’s mobility

The mobility of a node increases, the size of a packet Sp sent from a node to its neighbor nodes i decreases as following :

γ : Scaling parameter an

υi : The relative mobility speed of the source node and intermediate node =1 kb

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Algorithm(cont..)

4.Soft-deadline based forwarding scheduling algorithm An intermediate node first forwards the packet with the least time

allowed to wait before being packet forwarding A forwarding node can use the least slack first (LSF) scheduling

algorithm

The slack time of a packet p is defined as :

Dp : Deadline of packet p t : The current time c’ : The remaining packet transmission time of the packet

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Algorithm(cont..)

5.Data redundancy elimination based transmission The APs and mobile nodes can overhead and cache packets Use an end-to-end traffic redundancy elimination (TRE) algorithm

eliminates the redundant data to improve the QoS of the packet transmission

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Advantages

Guarantee QoS routing

Reduce total transmission delay

Increases node mobility

Achieve fairness in packet forwarding

Eliminates the redundant data

Improve the QoS of packet transmission

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