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Poster Paper Proc. of Int. Joint Colloquium on Emerging Technologies in Computer Electrical and Mechanical 2011

SAGO to assign maximum bandwidth for Qos routing in MANETS Kavya Hegde M.Tech(CSE) hegdekavyap@gmail.com VTU “Jnana sangama “, Belgaum

II. TIME SLOT ASSIGNMENT BY SAGO

Abstract— Applications of mobile ad hoc networks (MANETs) such as disaster recovery, search and rescue and military activities, are drawing more and more attentions in a civilian life for complements of the Internet. Providing sufficient bandwidth for multimedia applications in ad hoc networks is an urgent task because of the rising popularity of multimedia applications and potential commercial usage of ad hoc networks. Bandwidth is more difficult to guarantee in ad hoc networks than in other types of networks, and providing endto-end bandwidth guarantee is a critical and challenging problem in ad hoc networks because of multihop, mutual radio interference and node mobility. Time slot assignment is essential to provide the bandwidth in TDMA (Time Division Multiple Access) -based MANETs, which are the focus of attention of this paper because of its collision-free packet transmission with QoS support. In this paper, a new time slot assignment algorithm-SAGO (Slot Assignment by Global Overview) is proposed, by which more available bandwidth can be obtained.

Suppose there is a route for transmitting multimedia data. It is assumed that the number of links of this route is known and free time slots of every link of this route are also known. It should be noted that the assignment avoids radio wave interference so that once a time slot of a link is assigned then the same time slots of its one-hop neighbor links and twohop neighbor links cannot be assigned any more. SAGO (Slot Assignment by Global Overview) performs the assignment from a global viewpoint, whereas the conventional approximate methods do the assignment through the means of local searching. This global treatment makes its assignment better approximation than conventional methods. The principles of this global treatment are as follows: - The assignment trial is started from the bottleneck link that has the smallest number of free slots and is continued in other links towards both end links. -Time slot assignment is tried assuming a tentative value of available bandwidth. -If the assignment trial becomes infeasible, the tentative value is decremented by 1 and the assignment trial is repeated until it becomes feasible. -The slots for the assignment are selected according to the order of their free times in the concerned links. SAGO can be described briefly by the following five steps. STEP 1. To find the starting link s from which the assignment will be started; STEP 2. To calculate the tentative bandwidth w; STEP3. To begin time slot assignment from the starting link s, select w timeslots from the starting link s; the time slot which is not used by its one-hop neighbors and two-hop neighbors will be firstly selected. STEP 4. To continue to assign toward the destination node direction; STEP 5. To continue to assign toward the source node direction.

Index Terms—Ad hoc network, QoS, bandwidth guarantee, time slot assignment

I. INTRODUCTION Ad hoc networks is a collection of wireless mobile hosts forming a temporary network without any infrastructure, Each node acts both as a router and as a host.In order to provide required bandwidth for multimedia applications, bandwidth calculation is firstly necessary for the routes through which multimedia data are transferred [2] [5]. Moreover, bandwidth of a route is measured in terms of the number of free slots available in a TDMA (Time Division Multiple Access) –based MANETs [3] [6] . Thus, time slot assignment is of first importance to provide the calculated bandwidth in TDMA-based MANETs, which are a focus of attention of this paper because of its collision-free packet transmission with QoS support [3] [7] [8].

Poster Paper Proc. of Int. Joint Colloquium on Emerging Technologies in Computer Electrical and Mechanical 2011 discovering a set of multiple disjoint paths and transmitting data along these paths. BARP retains the route discovery mechanism of DSR whereby multiple routes can be returned. Each route discovered is stored in the route cache with a unique route index. So it is easy for us to pick multiple routes. There is no looping problem in BARP, as the route information is contained inside the packet itself; routing loops, either shortlived or long-lived, cannot be formed as they can be immediately detected and eliminated. Figure 1: shows the operation of BARP.

Figure 2: RREQ and RREP in BARP Protocol

BARP extended DSR and it is different from DSR in the following aspects. (1) All the route request packets are forwarded as far as the destination node of the route and all the route reply packets are generated by the destination node and returned to the source node. In DSR, when a node receives a route request for which it has a route in its cache, it does not propagate the route request, but instead returns a route reply to the source node. For example, in Figures 2, there exists a route C->D->E in the cache of node C. When RREQ reaches node C, node C will propagate it till node E in Figure 2 according to BARP, though there is a route from node C to node E in the cache of node C. (2) When the route request packets are transferred, the information of already assigned and used time slots of every route between a pair of source node and destination node is gathered by the destination node at the same time. Thus, the destination node keeps the status information of time slots concerned in every route between a pair of source node and destination node. (3) Using the information of already assigned time slots stored in the destination node of the route, the route of maximum bandwidth can be found by SAGO[4]. IV. CONLUSION This paper considered the time slot assignment for bandwidth guarantee in TDMA-based mobile ad hoc networks. We presented an effective time slot assignment algorithm â&#x20AC;&#x201C; SAGO, by which time slot assignment is done from a global overview, that is, time slot assignment is based on the usage of global information such as finding of bottleneck of a route, primary bandwidth evaluation of a route and assignment of time slot according the order of their free times in the concerned links, i.e. its one-hop and two-hop neighbor links. By time slot assignment method, more available bandwidth is obtained than the conventional approximate method and much less time is consumed. Thus, proposed time slot assignment method is most practical in mobile ad

Figure:1 Flow chart of SAGO

III. QOS ROUTING WITH MAXIMUM BANDWIDTH Bandwidth-aware dynamic source routing algorithm, referred to as BARP Protocol, which provides QoS guarantees with respect to end-to-end reliability by ÂŠ 2011 ACEEE DOI: 02.CEM.2011.01.538

Poster Paper Proc. of Int. Joint Colloquium on Emerging Technologies in Computer Electrical and Mechanical 2011 [4] W.-H. Liao, Y.-C. Tseng, K.-P. Shih, “A TDMA-based bandwidth reservation protocol for QoS routing in a wireless mobile ad hoc network”, in:Proceedings of the IEEE International Conference on Communications (ICC), vol. 5,2002, pp. 3186–3190. [5] J. Li, C. Blake, D. D. Couto, H. Lee, and R. Morris, “Capacity of ad hoc wireless networks,” in Proc. 7th ACM Int. Conf. Mobile Comput. Netw.(MobiCom’01), 2001, pp. 61–69. [6] W.-H. Liao, Y.-C. Tseng, K.-P. Shih, “A TDMA-based bandwidth reservation protocol for QoS routing in a wireless mobile ad hoc network”, in: Proceedings of the IEEE International Conference on Communications (ICC), vol. 5, 2002, pp. 3186–3190. [7] Li Hongyan and Shahrokh Valaee, “An Effcient Algorithm for Time Slot Assignment in Ad Hoc Networks”, in the proceedings of 22nd Biennial Symposium in Commucications, June 2004 [8] C. Zhu and M. S. Corson, .A _ve-phase reservation protocol (FPRP) for mobile ad hoc networks,. Wireless networks, vol. 7,pp. 371-384, July 2001.

hoc networks. In addition, the results of bandwidth calculation by our time slot assignment algorithm – SAGO can be used for QoS-routing, using BARP protocol the max bandwidth for Qos routing is achieved. The combination for these two algorithm give a good performance. REFERENCES [1] IETF MANET Working Grouphttp://www.ietf.org/ html.charters/manet-charter.html. [2] Jianping Li and Yasushi Wakahara, “End-to-end Bandwidth Guarantee in a Mobile Ad Hoc Network,” in Proc. Multimedia, Distributed, Cooperative and Mobile Symposium, Japan, 2006, pp. 389–392. [3] Imad Jawhar and Jie Wu, “QoS Support in TDMA-based Mobile Ad Hoc Networks,” Journal of Computer Science and Technology, vol. 20, pp. 797-810, November 2005.