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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013)

486

QoS Aware Routing and Admission Control in MANET

Mr. Yadav M. V.

1

, Mr. Chavan G. T.

2

1PG student, 2Professors, Pune University, Pune

Abstract—It is dicult to provide quality of service (QoS) assurances in a mobile ad hoc network (MANET) due to node mobility, distributed channel access, fading radio signals, a lack of centralized co-ordination, and the unreliable nature of the wireless channel. This application gives a thorough overview of QoS routing metrics, resources, and factors aecting performance in the MANET. This application is aimed at identifying the issues and challenges involved in providing QoS in MANETs, overcoming these issues by using QoS aware routing and admission control mechanism which are required to ensure high levels of QoS, improving bandwidth, throughput and minimizing packet loss rate and end to end de-lay QoS metrics. Distributed Admission Control Mechanism (DACME) reduces the complexity for establishing QoS sessions and be sample admission control scheme with low complexity. The aim here is to improve peer to peer communication in wireless mobile ad hoc networks by identifying the location of mobile node using Predictive Location Based Routing Protocol (PLBRP) and Admission Control mechanism. This application can adapt to applications with bandwidth, delay and jitter constraints .This application proposes optimizations based on interactions between routing, and admission control layers which oer important performance improvements.

KeywordsQuality of Service (QoS), Admission Control, Predictive Location Based Routing Protocol (PLBRP).

I. INTRODUCTION

Quality of Service (QoS) is a generic term collectively used to assess the usefulness of any system with user‟s perspective. Quality of service routing is a routing mechanism under which paths are generated based on some knowledge of the quality of network, and then selected according to the quality of service requirements of flows The purpose of this application is to convict, analyze and define high-level needs and features of the QoS aware routing and admission control in MANET. It focuses on the QoS improvement while routing the packet. The main goal of QoS provisioning is to achieve a more deterministic network behavior, so that information carried by the network can be better delivered and network resources are better utilized. The network services can be characterized by a pre specified services requirements such as maximum delay, maximum delay variance (jitter), mini-mum bandwidth and maximum packet loss rate etc. The current ad hoc networks (MANETs) are not able to satisfy the requirements of quality of service (QoS).

In Ad-hoc networks, the routing phase plays an important role for improving Quality of Services. There are some challenges faced while providing QoS in MANET due to dynamic network topology, network flow stops receiving QoS provisions due to path breaks so new path must be established, causing data loss and delays. Again link state changes continuously and flow states change over time. There is no central control in Mo-bile Ad-hoc NETwork. One more challenge is of limited resource availability in ad-hoc network in terms of Bandwidth, battery life, storage, processing capabilities etc.

II. RELATED WORK

The MANET is composed of hosts that communicate each other over a shared wireless medium. Routes are mostly multi-hop, because of limited radio propagation range. For easy deployment, mobile nodes don‟t depend on the external energy supply, so they are usually battery powered, which is often a limiting factor. Neighbor nodes share the radio transmission channel with limited bandwidth. The network topology can change during operation then Determining and maintaining the network topology in a distributed fashion is a most challenging problem for example, due to adding or removing nodes.

Table driven routings (or named proactive routing) continuously maintain routs in each node so as to forwarding packets immediately without waiting for rout discovery. Due to topology changing nature of Ad Hoc

networks, table driven routings suffer high maintenance

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013)

487 Proactive (or table driven) routing schemes, such as DSDV, AODV, DSR [3], keep the next hop information on a route toward destination. Due to the node mobility and topology change, the maintaining overhead of proactive routing is quadratic in network size. On the contrary, LBR usually requires only ac-curate neighborhood information and rough destination position, thus it produces low maintenance cost and is localized in nature. Because of localization, LBR schemes have high scalability. This application investigates the problem of QoS routing in Ad Hoc networks. In view of the advantages of LBR, proposed a location based QoS routing protocol for Ad Hoc system. In the proposed application, named QoS Aware routing and admission control protocol, first find the exact location of a node then predict the location of a destination node and apply admission control while routing the packet.

III. PROGRAMERS DESIGN

Let us consider architectural design of QoS aware routing and admission control system which consists of

four different modules viz. Current Location Estimation,

[image:2.612.54.278.433.590.2]

Predictive Location Based Routing Protocol, Distributed admission control agent and finally comparison of QoS parameters which will generates graphs to prove that this system improves QoS parameters.

Fig 1: Architecture

In QoS Aware routing and admission control in MANET, first estimate nodes exact location in the network and then predict the location of destination node and after finding locations of both source and destination then apply admission control part on route to check whether all QoS parameters are available or not to reach up to destination. Here exact location of a node is find by location estimation methods and then prediction of a destination node is done by predictive location based routing protocol and finally admission control applied on the available route.

Predictive Location Based QoS Routing protocol: This protocol is present at the network level i.e. the state in-formation distribution and location-and-delay prediction schemes [8] for QoS routing. It is essential to use a predictive scheme because state information in an ad hoc net-work, does not remain current for very long. The motivation behind using a location-based scheme rather than a hop-based scheme is to solve the problem of routing is as follows: The updates of geographic location that use in our mechanism can also become obsolete as the node moves from one location to another, just as routing table updates can. Two methods are used to satisfy location requirements as a) the location-resource update protocol which allows for location/resource information distribution, (b) the location prediction scheme to estimate new location at a future instant, based on information regarding previous locations and previous end-to-end delays.

Update Protocol: The update protocol is crucial for distribution of geographical location and resource information. Here consider resources such as battery power, queuing space, processor speed, transmission range, etc. There are two types of updates:

[image:2.612.374.514.490.591.2]

1. Type 1 update: A type 1 update is generated periodically. It can be generated with a constant frequency, i.e. the time between successive type 1 updates remains constant. Alternatively, the frequency of the type 1 up-date can vary linearly between a maximum (fmax) and a minimum (fmin) threshold, with the velocity v of the node. Consequently, the distance travelled between successive type 1 updates remains constant. This function is illustrated in Fig 2.

Fig 2: Variation of update frequency of type 1 update with velocity of the node [9]

2. Type 2 update: A type 2 update is generated when there is a considerable change in the nodes velocity or direction of motion. From its recent history (i.e. from re-cent updates), the mobile node can calculate an expected location that it should be in at a particular instant. The node then periodically checks if it has deviated a distance greater

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013)

488

If it has deviated more than a distance δ from its

expected location, a type 2 update is generated. Suppose that the periodic check for a particular node is scheduled at time t. Then, the node finds whether it has deviated more

than a distance δ from its expected location (xe,ye)at t.

Further, let us suppose that its own most recent update was

generated at time t, = tc - t, where Δt is some time interval.

Let us assume this update was generated at point (x,y), reporting a velocity v, and direction such that the node moves at an anti-clockwise angle theta to the horizontal. Also, let us assume the current location of the node at the

time of checking tc is (xc,yc). Let the velocity at the time of

checking v remain unchanged since the last update, i.e. Vc=v. This situation is illustrated in Figure 2.Then, expected location (xe,ye) is given by the equations [9]:

xe= x+v.(te-t) Cos θ (1)

ye= y+v.(te-t) Sinθ (2)

If [( xe-xc )2+(ye-yc )2]1/2> δ, then a type 2 update due to

significant change in the pattern of motion is generated at the time of checking, i.e.tc. Care is taken to see that Îť is large enough to prevent the reporting of minor pertur-bations in direction. Alternatively, if there is a significant change in the velocity at t also a type 2 update due to significant change in the pattern of motion is generated. A

type 2 update could also be generated if vc-v>1 m/s. If

there is no significant change in either velocity or direction, then no type 2 update is generated. The frequency of the periodic check for significant change in the pattern of motion is obviously greater than that of the minimum threshold fmin of the type 1 update. Thus, any update that is not a periodic update, but is generated by the significant change of some resource/property of the node, is categorized as a type 2 update. Update packets contain timestamps, current geometric co-ordinates, direction of motion, velocity and also resource information pertaining to the node that is used in QoS routing. Updates also contain a motion stability parameter, which is also used in QoS routing. The motion stability parameter is a special QoS parameter, represented by a single bit that indicates whether the update has been generated by a routine periodic timeout or due to the nodes changed pattern of motion. It indicates whether the update is a type 1 or a type 2 update. Conceptually, the motion stability parameter indicates whether the velocity and direction of motion of the node are constant, and hence predictable, or are dynamically varying. If the velocity and direction are dynamically varying, they are hard to predict accurately. Hence, such nodes with dynamically varying patterns of motion should not be used as intermediate nodes for connections requiring low delay and low delay jitter.

[image:3.612.347.550.236.344.2]

Using such nodes with unstable motion patterns as intermediate nodes results in frequent re-routing, which increases delay and delay jitter. The update packet also has a field for the mobile node to indicate whether it is moving in a piecewise-linear pattern (i.e. with angular velocity zero) or angular pattern (i.e. with angular velocity greater than zero).

Fig 3: Variation of update frequency of type 1 update with velocity of the node [9]

Predictions: When a packet arrives at a node a to be routed to a particular destination b, a has to follow a two step process to forward the packet along. The first step is to predict the geographic location of the destination b as well as the candidate next hop nodes, at the instant when this packet will reach the respective nodes. Hence, this step involves a location as well as propagation delay prediction. The location prediction is used to determine the geographical location of some node (either an intermediate node or the destination b) at a particular instant of time tp in the future when the packet reaches it. The propagation delay is used to estimate the value of tp used in the above location prediction. These predictions are performed based on previous updates of the respective nodes.

I. Location Prediction: Assuming that a node moving in a piecewise linear pattern. Between successive update points, the node has moved in a straight line. Two previous

updates are sufficient to predict a future location of the

mobile node in the plane for a piecewise linear motion pattern and update packets that do not contain direction information,. Let (x1, y1) at t1 and (x2,y2) at t2(t2 >t1) be the

latest two updates respectively from adestination node b to

a particular correspondent node a. Let the second update

also indicate v to be the velocity of b at (x2,y2). Assume that

a wishes to predict the location (xp,yp) of b at some instant

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013)

489 From fig 3, using similarity of triangles, We get

[image:4.612.47.233.131.310.2]

(y2 - y1) / (yp- y1) = (x2-x1) / (xp-x1) (3) Solving for yp from the above equation, yp= y1+(xp-x1) (y2-y1) /(x2-x1) (4)

Fig 4: Prediction of future location [9]

Using the above equation, a can calculate yp if it knows

xp, which in turn can be calculated as follows. Using

similarity of triangles again, we get: yp - y2 = (y2-y1) (xp-x2) / (x2-x1) (5)

Also, using Pythagoras theorem, (xp-x2)2 + (yp-y2)2 =v2 (tp - t2)2 (6)

Substituting for yp - y2 from Equation 5 in the above and

solving for xp, we get:

xp = x2+[(v(tp-t2) (x2-x1))/[(x2-x1) 2

+(y2-y1) 2

]1/2] (7) The second step is to perform QoS routing based on the information, determined in the first step, as well as the resource-availability information for the candidate next-hop nodes.

II QoS Routing: The location-and-delay prediction is extensively used in the QoS routing decisions. The presented QoS routing algorithm belongs to the source routing category where each node a has information about the whole topology of the network. It can thus compute the route from itself to any other node, using the information it has, and can include this source route in the packet to be routed. The state information about the network stored at a node a consists of two tables - the update table and the route table. The update table contains information pertaining to every node that a receives up-dates from, i.e. every node in the network. When an update packet arrives at a node a from a node b, the in-formation it contains is used to update this table.

Node ID of b is stored in update table, the time the update packet was sent, the time it was received, the geometric co-ordinates of b bas contained in the update packet, the speed of b bas contained in the update packet,

the resourceparameters of b and the direction of motion of

[image:4.612.330.565.208.375.2]

b. The route table at a node „a‟ contains all the routes originating at a.

Fig 5: DACME Agent [5]

When an update is received at a node a, it checks if any of the routes in its route table is broken or is about to be broken. A route could be broken either when neighboring nodes move out of each other‟s trans-mission ranges or, alternatively, if the resource availability at some intermediate node changes and this results in the node being unable to support the QoS requirements of the connection. In either case, route recomputation should be initiated. Due to the location prediction based on the updates, system can predict if neighboring nodes on a route are about to move out of each other‟s transmission range. Thus, route recomputation could be initiated before the route actually breaks [9].

III Distributed Admission Control Mechanism (DACME): The main component of our QoS architecture is DACME, a probe based admission control mechanism that performs end-to-end QoS measurements according to the QoS requirements of multimedia streams. The main elements of DACME are the QoS measurement module and the packet filter. The QoS measurement module is responsible for assessing QoS parameters on an end-to-end

path, while the packet filter blocks all traffic that is not

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013)

490 An application that wishes to benefit from DACME must register itself with the DACME agent, indicating the desired destination IP address and the source and destination UDP ports, along with a QoS specification (QSPEC), stating the requested bandwidth, delay, and jitter: (BR, DR, JR). If any among the avail-able bandwidth, the end-to-end delay, or the jitter values does not meet the applications requirements, DACME [4] will notify this event to the application. Once registration is successfully completed, the QoS measurement module is activated; it will periodically perform path probing between the source and destination. The purpose is to assess if the path can meet the QoS requirements (QSPEC), which may be defined in terms of end-to-end bandwidth, delay, and/or jitter. The destination agent, upon receiving probe packets, will update the destination statistics table where it keeps per-source information of the packets received during the current probing period. After receiving the last packet of a probe (or if a timeout is triggered), the destination agent will send a reply back to the source DACME agent. The QoS measurement module, upon receiving each probe reply, will update the state of the path using per-connection band-width, delay, and jitter flags. Once enough information is gathered, it checks all the registered connections towards that destination, and then decides whether a connection should be accepted, preserved, or rejected, updating the Port state table accordingly (defining a connection status flag as accepts or drop).

IV. CONCLUSION

This project identifies the issues and challenges involved in providing QoS in MANETs and overcome to these issues by using QoS aware routing and admission control mechanism which are required to ensure high levels of QoS. Predictive location based routing protocol is used to predict the location of a mobile node which improves bandwidth and end to end delay metrics. DACME reduce the complexity for establishing QoS sessions and be sample admission control scheme with low complexity by using distributed admission control protocol algorithms at source, intermediate and destination node.

Acknowledgments

I thanks to my guide Prof. Mr. Chavan G. T. who has guided me throughout the semester.

REFERENCES

[1] A. Boomarani Malany et. al., “Throughput and Delay Comparison of MANET Routing Protocols”, Int. J. Open Problems Compt. Math., Vol. 2, No. 3, September 2009 ISSN 1998-6262, 2009, www.i-csrs.org.

[2] C. R. Lin and J. S. Liu, “QoS Routing in Ad-Hoc Wireless Networks.”, IEEE Journal On Selected Areas In Communications, Vol.17, No.8, pages 1426-1438, August 2009.

[3] G. Santhi and Alamelu Nachiappan, “A Survey of QoS Routing Protocols for Mobile Ad Hoc Networks”, International journal of computer science & information Technology (IJCSIT) Vol.2, No.4, Au-gust 2010.

[4] JooSang Youn, Sangheon Pack and Yong-Geun Hong, “ Distributed admission control protocol for end-to- end QoS assurance in ad hoc wireless net-works ”, youn et al. EURASIP Journal on Wireless Communications and Networking 2011, 2011:163.

[5] L Hanzo II and R. Tafazolli, “Admission Control Schemes for 802.11-Based Multi-Hop Mobile Ad Hoc Networks: A Survey”, IEEE Comm. Surveys and Tu-torials, vol. 11, no. 4, pp. 78-108, Oct.- Dec 2009.

[6] L. Hanzo II and R. Tafazolli, “A survey of QoS Routing Solutions for Mobile Ad Hoc Networks”, IEEE comm., vol 9, no. 2, 2nd MAY 2007.

[7] L. Hanzo II and R. Tafazolli, “QoS-Aware Routing and Admission Control in Shadow-Fading Environments for Multirate MANETs”, Wiley J. Wireless Comm. and Mobile Computing, vol 10,no.5, May. 2011.

[8] M. P. Malumbres, C. T. Calafate, “QoS Support in MANETs: A Modular Architecture Based on the IEEE 802.11e Technology”, IEEE Transaction on Circuits and systems, vol. 19, NO. 5, MAY 2009.

[9] Samarth H. Shah, Klara Nahrstedt, “Predictive Location Based QoS Routing in Mobile Ad Hoc Net-works”, Department of Computer Science University of Illinois at Urbana-Champaign Urbana, IL 61801, U.S.A, 2002.

Figure

Fig 2: Variation of update frequency of type 1 update with velocity of  the node [9]
Fig 3: Variation of update frequency of type 1 update with velocity of the node [9]
Fig 5: DACME Agent [5]

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