A. Venugopal Reddy

Performance Comparison of On-Demand and Table Driven Ad Hoc Routing Protocols Using NCTUns

The main aim of any ad-hoc network routing protocol is to meet the challenges of the dynamically changing topology and establish a correct and an efficient communication path between any two nodes with minimum routing overhead and bandwidth consumption. The design problem of such a routing protocol is not simple since an ad hoc environment introduces new challenges that are not present in fixed networks. A number of routing protocols have been proposed for this purpose like Ad Hoc On Demand Distance Vector (AODV), Dynamic Source Routing (DSR), Destination- Sequenced Distance Vector (DSDV). In this paper, we study and compare the performance of the following three routing protocols AODV, DSR and DSDV. NCTUns 4.0 is used to study the relative performance of the routing protocols according to different criteria. The notable point of our analysis is that, it is based on varying number of nodes in the ad hoc network.

A review of gateway load balancing strategies in Integrated Internet-MANET

Interconnection of wired Internet and wireless mobile ad hoc networks, called Integrated Internet-MANET enables communication between wired and wireless peers. Many strategies exist which provide Internet connectivity to the mobile ad hoc network nodes through one or more Internet gateways. Mobile nodes need to be registered with an Internet gateway in order to communicate across the Internet. A key issue in such strategies is to distribute the Internet bound traffic across the Internet gateways evenly. The problem of Internet gateway load balancing has been addressed by researchers in interesting ways. In this paper, we present a review of the gateway load balancing solutions under common parameters. In the second part of the paper, a new gateway load balancing strategy based on a load balanced routing protocol called Modified AODV is proposed and is simulated using the ns-2 simulator.

Path Load Balanced-Fuzzy Logic based Adaptive Gateway Discovery in integrated Internet-MANET

In this paper, we propose a modified form of the hybrid gateway discovery in integrated Internet-MANET. A modified hybrid gateway discovery approach is called an adaptive gateway discovery mechanism. Three issues are considered together in the proposed adaptive gateway discovery: the load balancing in routing of packets, the range, and periodicity of a gateway advertisement message. We address these three issues by making use of existing approaches. Based on simulation studies, we show that our approach gives better results than the existing approach.

An efficient integrated routing protocol for interconnecting mobile ad hoc networks and the internet

There has been a massive growth in wireless communications in recent years. Access to the Internet via wireless communication devices has become an important issue due to the trend of an all-IP network in the 4G wireless networks. One such wireless technology gaining popularity is Wireless Mobile ad hoc Network, which is an infrastructure-less, autonomous, stand alone and self organizing network. It can be simply and flexibly deployed in almost any environment. However it has limited wireless coverage and limited connectivity. With the integration of MANET routing protocol and IP protocol, Internet connectivity to the MANET nodes can be achieved. Solutions to the integration problem, introduce an intermediate entity with hybrid mechanisms enabling it to connect to two different networks. In this paper, an extended DSDV protocol, named as Efficient DSDV (Eff-DSDV) protocol is used to provide bidirectional connectivity between ad hoc nodes and the hosts in the Infrastructure-based networks like Internet. The proposed framework uses one of the ad hoc hosts known as Mobile Internet Gateway (MIG) to act as a bridge between the two networks. The detailed performance comparison has been made between the proposed approach using Eff-DSDV routing protocol and the existing integration strategies. The simulation results shows that the performance of the proposed strategy using Eff-DSDV is superior to the existing integration strategies.

The Effective Multicasting Routing Protocol in Wireless Mobile Adhoc Network

With the advance of wireless communication technology, portable computers with radios are being increasingly deployed in common activities. Applications such as conferences, meetings, lectures, crowed control, search and rescue, disaster recovery, and automated battlefields typically do not have central administration. In adhoc networks, each host must act as a router since routes are mostly multi hop. Nodes in such a networks move arbitrarily, thus network topology changes frequently. The protocol termed ODMRP is a mesh-based instead of tree -based, multicast protocol that provides richer connectivity among multicast members. The major strengths of ODMRP are its simplicity. We can further improve its performance. We propose new techniques to enhance the effectiveness and efficiency of ODMRP. Primary goals of enhanced ODMRP: Improve adaptivity to node movement patterns. Transmit control packets only when necessary, Reconstruct routes in anticipation of topology changes, Improve hop-by-hop transmission reliability, and eliminate route acquisition latency.

Performance Improvement of Web Page Genre Classification

The dynamic nature of web and with the increase of the number of web pages, it is very difficult to search required web pages easily and quickly out of thousands of web pages retrieved by a search engine. The solution to this problem is to classify the web pages according to their genre. Automatic genre identification of web pages has become an important area in web page classification, because it can be used to improve the quality of web search results and also to reduce the search time. In this paper, a Combined Stemming Approach (CSA) is proposed to extract genre relevant words and to classify web pages by genre (nontopical) based on word level and linguistic features. Experiments were performed on 7-genre corpus. In order to improve the accuracy of the results, we applied combined stemming and stop word elimination techniques. The proposed approach of extracting features discriminates web pages by genre. The classification results obtained using Random Forest classifier was compared with the results of other researchers, who worked on the same corpus. It is shown that the method proposed is superior in performance in terms of accuracy. General Terms Classification, Stemming

Load balanced fuzzy control based adaptive gateway discovery in Integrated Internet MANET

Integrated Internet-MANET (IIM) architecture is a hybrid network which is an interconnection of the wired Internet and wireless MANET. This interconnection is facilitated through gateways. Some of the important issues in this integration are gateway discovery and gateway load balancing. So far, these issues have been addressed separately in the literature. The issues of gateway load balancing and gateway discovery are inherently interrelated. In this paper, the issues of gateway load balancing and gateway discovery are addressed together. The proposed mechanism uses the WLB-AODV routing protocol for gateway load balancing and treats the problem of finding efficient values to gateway discovery parameters as a control system and uses the Mamdani Architecture for Fuzzy Control. The proposed protocol has been simulated in ns-2 network simulator. Simulation results show that the proposed protocol gives better performance than the existing solution in terms of packet delivery ratio, end-to-end delay and normalized routing load.

An Effective Gateway Discovery Mechanism in an Integrated Internet-MANET (IIM)

The Integration of the MANETs and infrastructure networks such as Internet, known as heterogeneous network, extends the network coverage and increases the application domain of the MANET. Communication between a mobile device in an ad hoc network and a fixed device on the Internet is achieved using gateways, which acts as a bridge between them. The ad hoc routing protocol AODV is extended and used to achieve interconnection between a MANET and the Internet. In the existing approaches of gateway discovery either interface queue length or the minimum hop metric criteria or a combination is used for selecting the gateway by the mobile nodes. In the proposed approach, an efficient proactive gateway discovery algorithm is devised that takes into account the length of the routing queue in addition to the minimum hop count metric for selecting an efficient gateway and also selecting the routes to other mobile nodes. This is a novel strategy of gateway discovery. This approach is implemented by calculating the load along a path and updating the routing entry as the route requests are processed from one mobile node to the other. This allows usage of updated routes without waiting for the gateway advertisements for updating the routing entries. It also reduces the delay along the path for the packets traversing within the ad hoc network. The use of this concept increases the throughput by choosing the less congested paths and reduces the routing overhead. In this paper the impact of this new approach is investigated. Simulation results indicate that our protocol outperforms other approaches.

Mamdani Fuzzy Control based adaptive gateway discovery for ubiquitous Internet access in MANET

Ubiquitous Internet access has become a reality with the proliferation of mobile devices. One of the architectures which have the potential to abet ubiquitous Internet access is the Integrated Internet-MANET architecture, which is an interconnection of the wired Internet with wireless MANET. Gateway discovery and gateway load balancing are important issues in Integrated Internet-MANET and have been addressed separately in the literature. In this paper a new solution which addresses these two issues together is proposed. In the proposed mechanism, the problem of finding efficient values to gateway discovery parameters is treated as a control system which uses the Mamdani Architecture for Fuzzy Control. Gateway load balancing is achieved through the WLB-AODV routing protocol. The proposed protocol has been simulated in ns-2 network simulator. Simulation results show that the proposed protocol gives better packet delivery ratio and comparable end to end delay to the existing solution.

Web Page Genre Classification: Impact of n-Gram Lengths

pages are discriminated based on their topic and genre. Web page genres are capable to improve the modern search engines to focus on the users information need. In this paper, web pages are represented using character n-grams. Character n-gram representation is language independent and allows automatic extraction of features from a web page. Character n-gram representation of a web page can be used efficiently to classify a web page by genre. Support Vector Machine (SVM) classification model is used for classification and experiments were carried out on 7-Genre corpus by varying the length of n-grams. It is observed that the performance in terms of F- measure improves as n-gram lengths are varied from 3 to 5 and it is also observed that performance degrades as the n- gram length is further increased.