Hybrid Wireless Network Based on DTR [Distributed Three Hop Routing Protocol]

Hybrid Wireless Network Based on DTR [Distributed Three Hop Routing Protocol]

Aparna. M, Kalashree.U. L, Kumuda Mrs. Indu B, Asst.Professor, Dept of CSE,YDIT, Department of CSE, YDIT, Bangalore .

Bangalore, India Affliated to VTU,India

Abstract: Wireless networks using Hybrid technology combining the advantages of both infrastructure wireless networks and mobile ad-hoc networks and have been receiving increased attention due to their ultra-high performance. For high network capacity and scalability, an efficient data routing protocol is important, However, most protocols standard for these networks simply combine the routing principles namely ad-hoc Transmission mode with the advance technique included as cellular transmission mode, which in return inherits the drawbacks of ad-hoc transmission. This paper presents a Distributed Three-hop Routing protocol (DTR) for wireless networks using hybrid technology. Achieving full advantage of the widespread of base stations, a message data stream can be divided into segments and transmits the segments in a distributed approach. It makes full orbital (spatial) reuse of a system via its ad-hoc interface and alleviates mobile gateway congestion via its cellular interface with faster speed or high speed. Furthermore, passing segments to a number of base stations simultaneously, it increases throughput and makes complete use of base stations which are widespread. In addition to this, DTR relatively lowers overhead due to short path lengths and it terminates of route discovery and maintenance. DTR is also having congestion control algorithm to disapprove overloading of base stations. Theoretical simulation analysis and results show the dominance of DTR in evaluation with other routing protocols in terms of throughput capacity, scalability and mobility pliability. The Results also show the helpfulness of the congestion control algorithm in balancing the load between base stations.

Keywords Hybrid wireless networks, Routing algorithm, Load balancing, Congestion control Introduction.

1. INTRODUCTION

   In past few years, wireless networks including Transportation wireless networks and mobile ad-hoc networks (MANETs) have paying attention significantly to explore interest. The mounting yearning to increase wireless network Capacity for high performance applications has encouraged the development of hybrid wireless networks [1]. A hybrid wireless network consists of both a transportation Wireless network and a mobile adhoc network. Wireless devices such as smart-phones, tablets and laptops, Have both an infrastructure interface and an adhoc Interface. As the number of such devices has been escalating sharply in recent years, hybrid communication Structure will be broadly used in the near outlook. Such a Structure specially combines the Inherent advantages and overcome the disadvantages of the infrastructure wireless networks and mobile ad-hoc networks In a mobile ad-hoc network, with the absence of central control transportation, data is routed to its target through the intermediate nodes in a multi-hop manner. The multi-hop

   routing needs on-demand route discovery or route maintenance. Since the messages are transmitted in wireless channels and through dynamic routing paths, mobile ad-hoc networks are not as reliable as infrastructure wireless networks. Furthermore, because of the multi-hop transmission feature, mobile ad-hoc networks are only suitable for local area data transmission. The infrastructure wireless network (e.g. cellular network) is the major means of wireless communication in our daily lives. It excels at inter- cell communication (i.e., communication between nodes in different cells) and Internet access. It makes possible the support of universal network connectivity and ubiquitous computing A hybrid wireless network synergistically combines an infrastructure wireless network and a mobile adhoc Network to leverage their advantages and overcome Their shortcomings, and finally increases the throughput capacity of a wide-area wireless network. A routing protocol is a critical component that affects the throughput capacity of a wireless network in data transmission. Most current routing protocols in hybrid wireless networks simply combine the cellular transmission mode (i.e. BS transmission mode) in infrastructure wireless networks and the ad-hoc transmission mode in mobile ad-hoc networks .That is, as shown in Figure 1 (a), the protocols use the multi-hop Routing to forward a message to the mobile gateway nodes that are closest to the BSes or have the highest bandwidth to the BSes. The bandwidth of a channel is the maximum throughput (i.e., transmission rate in bits/s) that can be achieved. The mobile gateway nodes then forward the messages to the BSes, functioning as bridges to connect the ad-hoc network and the infrastructure network. However, direct combination of the two transmission modes inherits the following problems that are rooted in the ad-hoc transmission mode. High overhead. Route discovery and maintenance incur high overhead. The wireless random access medium access control (MAC) required in mobile ad-hoc networks, which utilizes control handshaking and a back off mechanism, further increases overhead.

   Hotspots. The mobile gateway nodes can easily become hot spots. The RTS-CTS random access, in which most traffic goes through the same gateway and the flooding, employed in mobile ad-hoc routing to discover routes.

2. RELATED WORKS

   In order to increase the capacity of hybrid wireless networks, various routing methods with different features Have been proposed. One group of routing methods integrate the ad-hoc

   Transmission mode and the cellular transmission mode [1, 5, 6, 14, 1618]. Dousse et al. [6] built a Poisson Boolean model to study how a BS increases the capacity of a MANET. Lin et al. [5] proposed a Multihop Cellular Network and derived its throughput. Hsieh et al. [14] investigated a hybrid IEEE 802.11 network architecture with both a distributed Coordination function and a point coordination function.

   Luo et al. [1] proposed a unified cellular and ad-hoc network architecture for wireless communication. Cho et al.

   [16] studied the impact of concurrent transmission in a downlink direction (i.e. from BSes to mobile nodes) on the system capacity of a hybrid wireless network. In inter-cell transmission [1, 5, 6], a message is forwarded via the ad-hoc interface to the gateway mobile node that is closest to or has the highest uplink transmission bandwidth to a BS. DTR is similar to the Two-hop transmission protocol [19] in terms of the elimination of route maintenance and the limited number of hops in routing. In two-hop, when a nodes bandwidth to a BS is larger than that of each neighbor, it directly sends a message to the BS. Otherwise, it chooses a neighbor with a higher channel and sends a message to it, which further forwards the message to the BS. DTR is different from two- hop in three aspects. First, Two-hop only considers the node transmission within a single cell, while DTR can also deal with inter-cell transmission, which is more challenging and more common than intra-cell communication in the real world. Second, DTR uses distributed transmission involving multiple cells, which makes full use of system resources and dynamically balances the traffic load between neighboring cells. In contrast, Two-hop employs single-path transmission.

   There are other methods proposed to improve routing performance in hybrid wireless networks. Wu et al. [3] proposed using ad-hoc relay stations to dynamically relay traffic from one cell to another in order to avoid trafic congestion in BSes. Li et al. [20] surveyed a number of multi- hop cellular network (MCN) architectures in literature, and compared and discussed methods to reduce the cost of deployment for MCNs and an optimal multicast strategy based on deduced throughput

3. DISTRIBUTED THREE-HOP ROUTING PROTOCOL

   1. Assumption and Overview

      Since BSes are connected with a wired backbone, we assume that there are no bandwidth and power constraints on transmissions between BSes. We use intermediate nodes to denote relay nodes that function as gateways connecting an infrastructure wireless network and a mobile ad-hoc network.We assume every mobile node is dual-mode; that is, it has ad-hoc network interface such as a WLAN radio interface and infrastructure network interface such as a 3G cellular interface Our DTR algorithm avoids the shortcomings of adhoc transmission in the previous routing algorithms that directly combine an ad-hoc transmission mode and a cellular transmission mode. Rather than using the multihop ad-hoc transmission, DTR uses two hop forwarding by relying on node movement and widespread base stations. All other aspects remain the same as those in the previous routing algorithms (including the interaction with the TCP layer).

   2. Uplink Data Routing

      Specifically, in the uplink routing, a source node initially divides its message stream into a number of segments, then transmits the segments to its neighbor nodes. The neighbor nodes forward segments to BSes, which will forward the segments to the BS where the destination resides. Below, we first explain how to define capacity, then introduce the way for a node to collect the capacity information from its neighbors, and finally present the details of the DTR routing algorithm.

   3. Downlink Data Routing and Data Reconstruction

   In this protocol, each mobile node is The home network of a node contains its registration information identified by its home address, which is a static IP address assigned by an

   ISP. In a hybrid wireless network, each BS periodically emits beacon signals to locate the mobile nodes in its range.

   D.Congestion Control in Base Stations

   In the hybrid wireless network, BSes send beacon messages to identify nearby mobile nodes. Taking advantage of this beacon strategy, once the workload of a BS, say Bi, transmission range. Then, nodes near Bi know that Bi is overloaded and will not forward segments to Bi. When a node near Bi, say mi, needs to forward a segment to a BS, it will send the segment to Bi based on the DTR algorithm.

4. EXISTING SYSTEM

   In existing system, they follow the basics concepts of Routing algorithm, and they can be explains through the following algorithms.

   After computing these algorithms their output is as shown

   and their output sis tabulated as shown above. These Disadvantages can be overcome through DTR algorithms and protocols

5. PERFORMANCE ANALYSIS OF THE DTR PROTOCOL

DTR

Achieves higher throughput and faster data forwarding speed by taking into account node capacity in data forwarding.

Besides mobile nodes, there are M BSes regularly deployed in the field. The BSes divide the area into a Hexagon tessellation, in which each hexagon has side Length h. DTR and DHybrid avoid long distance transmissions, leading to a higher transmission throughput.

1. PERFORMANCE EVALUATION

   The short routing paths in Two-hop reduce congestion and signal interference, thus enabling better spatial reuse as in DTR. As a result, gateway nodes connecting mobile nodes and BSes are not easily overloaded. Therefore, the throughput of two-hop is higher than Existing system.

2. Scalability

Figure 6 shows the average throughput measured in kbps per S-D pair of different routing protocols versus the number of mobile nodes in the system. The figure shows the throughput of DTR remains almost the same with different network sizes.

1. Transmission Delay

   Figure 8 shows the average transmission delay of SD pairs for successfully delivered messages in different routing protocols versus network size. The network size was varied from 20 to 100 with 20 increase in each step.

   From the figure, we see that DTR generates the smallest delay. In DTR, each source node first divides its messages into smaller segments and then forwards them to the nearby nodes with the highest capacity, which leads to more balanced transmission load distribution among nodes than the previous methods.

2. Effect of mobility

   Figure 11 plots the throughput of DTR, DHybrid, Two- hop, and AODV versus node moving speed. From the figure, we can see that the increasing mobility of the nodes does not adversely affect the performance of DTR and Two-hop. It is intriguing to find that high mobility can even help DTR to increase its throughput and that Two-hop generates constant throughput regardless of the mobility. This is because the DTR and Two-hop transmission modes do not need to query and rely on multi-hop paths; thus, they are not affected by the network partition and topology changes.

3. Load Distribution within a Cell

   In this experiment, we tested the load distribution of mobile nodes in a randomly chosen cell in the hybrid wireless network that employs each of the DTR, DHybrid, and Two- hop protocols. We normalized the distance from a mobile node to its base station according to the function D/Rb , where D is the actual distance and Rb is the radius of its cell.

   We divided the space of the cell into several concentric circles and measured the loads of the nodes on each circle to show the load distribution.

4. Effect of the Number of Routing Hops

   We conducted experiments to show the optimal number of routing hops for the routing in hybrid wireless networks. We tested the throughput per S-D pair for x- hop DTR, where x was varied from 1 to 4. In the 1-hop routing, a node directly transmits a message to the BS without message division. In the other routing protocols, the (x1) th hop chooses the best transmission mode between direct transmission and relay transmission. Also, in the 4-hop routing, the second relay node randomly the third relay node. Figure 13 shows the average throughput per S-D pair versus network size in DTR. As the figure shows, as the network size increases, the node throughput keeps constant regardless of the number of forwarding hops in a routing. The reason is the same as in Figure 6. We can also see from the figure that the throughput of the four protocols follows 3-hop>4-hop>2-hop>1-hop. In The 1-hop routing, each node only transmits segments directly to a BS regardless of its current transmission rate. In the 2-hop routing, if the transmission rate of a nodes neighbor is higher than that of the node, it asks its neighbor node to forward the segment to a BS.

   Therefore, the 2-hop routing has higher throughput than The 1-hop routing. The 3-hop routing can greatly increase the number of node options for segment routing since the number of nodes that the source node can encounter increases from d to d2, where d is the average node degree. Thus, a node with a greater transmission rate can be chosen as the forwarding node. Meanwhile, the 3-hop routing can greatly facilitate inter-cell communication because a node has a higher probability of reaching a neighboring BS within a 3-hop path length than within a 2-hop path length. Therefore, the throughput of the 3-hop routing is much higher than that of the 2-hop routing. The figure also shows that the 4-hop routing produces lower throughput than the 3-hop routing. The reason is that 3 hops are enough to find a hop with high transmission rate and achieve inter-cell communication because of widespread BSes. The 4-hop routing increases the forwarding delay due to the greater number of nodes in a route; thus, it cannot increase the uploading transmission rate of messages.

5. Load Distribution within a Cell

   In tis experiment, we tested the load distribution of mobile nodes in a randomly chosen cell in the hybrid wireless network that employs each of the DTR, DHybrid, and Two- hop protocols. We normalized the distance from a mobile node to its base station according to the function D/ Rb , where D is the actual distance and Rb is the radius of its cell. We divided the space of the cell into several concentric circles and measured the loads of the nodes on each circle to show the load distribution. Figure 14 shows the average load of a node corresponding to the normalized distance from itself to the BS in the chosen cell. The figure shows that most of the traffic load of DHybrid is located at nodes near the BS. The nodes far from the BS have very low load. The results

   conform to Proposition 4.3. In DHybrid, if a source node wants to access the Internet backbone or engage in inter-cell communication, it transmits the messages to the BSes in a multi-hop fashion. Therefore, the nodes near the BSes will have the highest load. On the other hand, since there is little traffic going through the nodes at the brim of a cell, the load of these nodes is small. As a result, some nodes can easily become hot spots while the resources of other nodes are not fully utilized. This load imbalance prevents DHybrid from fully utilizing system resources. The traffic load of DTR is almost evenly distributed in the system.

6. Load Balance between Cells

In this experiment, we tested the effectiveness of the Congestion control algorithm in DTR. We also added a Congestion control algorithm to DHybrid. In the algorithm, when a node receives beacon messages from its BS indicating that it is overloaded, the node broadcasts a query message to find a path to a nearby uncongested BS. We selected two BSes out of the total four BSes. In the range of each of the two selected BSes, we randomly selected one mobile node as the source node to send messages to a randomly selected destination node in the network. Once the source node moves out of the range of the selected BS, another mobile node in the range was selected as the source node. In order to show the load distribution of the BSes in different protocols, we ranked the BSes based on BS throughput. The BS with the highest throughput has a rank of 1.

REFERENCES

CONCLUSIONS

In this paper, we propose a Hybrid Wireless Network of Distributed Three-hop Routing (DTR) data routing protocol that integrates the duo-features of hybrid wireless networks in the data transmission process. In DTR, a source node is divided into a message stream and then into segments and further they transmits them to its itinerant neighbors, which further advance the segments to their final destination via a communications network. DTR sets the limits of the routing path length to three, and always arranges for high-capacity nodes to advance the data. Different most existing routing protocols, DTR produces considerably lowers transparency by terminating route discovery and maintenance. In accumulation, its distinguishing characteristics of short path length, short-distance transmission, and balanced load distribution provide high routing steadfastness and competence. DTR also has a congestion control algorithm to avoid load congestion in BSes in the case of unbalanced traffic distributions in networks. Notional analysis and replication results show that DTR can spectacularly improve the throughput capacity and scalability of hybrid wireless networks due to its high scalability, efficiency, and consistency and low overhead.

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