Roopam Gupta

Performance analysis of proposed local link repair schemes for ad hoc on demand distance vector

Reactive routing protocols are better options for the communication in ad hoc network. In this study, a novel approach for local link repairing of ad hoc on demand routing protocol is suggested for the performance enhancement of the basic protocol. Alternate route finding for next-to-next node in case of link breakage is a better option of route management. These protocols are beacon-less to improve bandwidth utilisation. Control overheads have been reduced by using 802.11b protocol to maintain connectivity of moving nodes. Significant improvement is observed in the Quality of service parameters like throughput, end-to-end delay, packet delivery ratio and link breakage through simulations.

Scalability enhancement of AODV using local link repairing

Dynamic change in the topology of an ad hoc network makes it difficult to design an efficient routing protocol. Scalability of an ad hoc network is also one of the important criteria of research in this field. Most of the research works in ad hoc network focus on routing and medium access protocols and produce simulation results for limited-size networks. Ad hoc on-demand distance vector (AODV) is one of the best reactive routing protocols. In this article, modified routing protocols based on local link repairing of AODV are proposed. Method of finding alternate routes for next-to-next node is proposed in case of link failure. These protocols are beacon-less, means periodic hello message is removed from the basic AODV to improve scalability. Few control packet formats have been changed to accommodate suggested modification. Proposed protocols are simulated to investigate scalability performance and compared with basic AODV protocol. This also proves that local link repairing of proposed protocol improves scalability of the network. From simulation results, it is clear that scalability performance of routing protocol is improved because of link repairing method. We have tested protocols for different terrain area with approximate constant node densities and different traffic load.

Route Discovery by Cross Layer Approach for MANET

Link breakage is of high probability in mobile wireless adhoc networks because of highly dynamic nature of MANET. This is because of limited transmission range, mobility and limited battery power. It becomes difficult to maintain continuous links in the networks. In AODV, node generates a RERR message for the given destination when it noticed that a link breakage has taken place. This hampers the continuity of the link and results in link breakage, in loss of some packets and increase in delay and overhead. Link breakage, delay and packet loss is not tolerable in real time communication and loss of packets, more overhead is not tolerable in non real time communication. So AODV is modified to cope up with these problems. An algorithm using cross layer approach is proposed which helps in maintaining the continuity of the network resulting in more throughput, less delay, less overhead and less battery power consumption which can be used for both real time and non real time communication.

Estimated new Routing Scheme in MANETs

High probability of disappointment in Ad-Hoc networks due to energy-tired nodes is one of the main limitations. If some nodes expire early due to lack of energy, they cannot transfer the data with each other. Therefore, excessive consumption of nodes energy should be prevented. Energy conservation of a Network is a major design issue since mobile devices are often embarrassed by the battery. After suitable election of one active node among several nodes an enormous amount of energy can be saved in any local networks. This paper aims energy conservation through hexagonal GAF grid structures with the help of most popular Location-Aided Routing (LAR) scheme. This scheme uses the location of mobile node through GPS technique to improve the performance matrices such as energy saving, routing overhead and network life time in Ad-Hoc Networks.

Routing protocols in Mobile Ad-Hoc Networks: An overview

MANETs can manage without fixed infrastructure and can stay active rapid changes in the network topology. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to appropriately route traffic. Routing with Scalable and robustness performance is one of the key challenges in deploying Mobile Ad-Hoc Networks. In this paper, we deliberate on different routing protocols which are widely used in MANETs. In order to operate the Ad-Hoc Networks as efficiently as possible, appropriate on-demand routing protocols have to be incorporated, to find effective routes between source and destination. This paper primarily concentrates to study the various performance metrics like such as, data packet delivery fraction, end to end delay and control packet etc. of the routing protocols. In particular, position-based routing protocols can route messages more efficiently to their destinations based on the destination node position, which is provided by a location service. As LAR, important performance matrices of Mobile Ad-Hoc Networks can be improved.

RDCLRP-route discovery by cross layer routing protocol for performance improvement

MANET links have dependency on node mobility and node battery power. If a nodes battery power goes below threshold or if a node goes out of transmission range lead to link failure causing degradation of networks performance. It could be alleviated by allowing cross layer interaction in the protocol stack. So RDCLRP is proposed for route discovery and route maintenance using adaptive hello warning message. HELLO warning message is used to give warning when link is going to break before link breakage to keep connectivity of the link and it is broadcasted whenever it is required and not periodically. This paper is targeted to improve network performance parameters such as throughput, delay, jitter, overhead and battery power consumption

A new framework for call admission control in wireless cellular network

Managing the limited amount of the radio spectrum is an important issue with increasing demand of the same. In recent work, we have introduced MAS (Multi-agent System) for channel assignment problem in wireless cellular networks. Iinstead of using a base station directly for negotiation, a multi-agent system comprising of software agents was designed to work at base station. The system consists of a collection of layers to take care of local and global scenario. In this paper we propose the combination of MAS with a new call admission control (CAC) mechanism based on fuzzy control. This paper aims to provide improvement in QoS parameters using fuzzy control at call admission level. From the simulation studies it is observed that combined approach of Multi-agent system and fuzzy control at initial level improves channel allocation and other QoS factors in an effective and efficient manner. The simulation results are presented on a benchmark 49 cell environment with 70 channels that validate the performance of this approach.

Optimization of Fidelity with Adaptive Genetic Watermarking Algorithm Using Roulette-Wheel

In Digital Watermarking a low energy signal is imperceptibly embedded in another signal. The low energy signal is called watermark. Earlier techniques based on spatial and frequency domain, had the problems of a poor fidelity especially with higher payloads of watermark image. Unsatisfactory value of Peak Signal to Noise Ratio (PSNR) of watermarked image resulting in image quality degradation was seen in varying degree, in various research works. This paper is an attempt to employ genetic algorithms to find suitable locations for watermark insertion within a cover image, to focus on the issue of optimizing fidelity. The paper uses a roulette-wheel selection strategy in genetic algorithm and investigates the variation of maximum fitness which reflects the higher PSNR of the watermarked image with respect to embedding strength, number of genes, and incremental payloads of watermark consisting of binary matrix. With the proper understanding and analysis of the results of this paper, a successful watermarking scheme can be obtained using Genetic algorithms, which may be useful when optimizing the fidelity aspect of digital watermarking.

DDCA in Cellular Network using Fuzzy Rule Based Multi- agent System

Present mobile networks have different Quality of Service (QoS) requirements to support increasing need with major objectives such as better admission control, effective bandwidth utilization, and fault tolerance. So the network aims at satisfying their demands without much degradation of quality in terms of call dropping and call blocking. It is possible by admission control algorithms and by optimizing the sharing and utilization of existing resources in an effective way. It improves the overall p erformance of the network system. This paper addresses different Quality of Service (QoS) requirements of the users of a cellular network with a focus on fuzzy based Call Admission Control Scheme (CAC) and optimized bandwidth allocation using M ulti Agent System M odel. We propose combined framework to address resource allocation problem. This problem can be dealt with the help of two issues in Admission control and Transmission control. The admission control – the decision to admit or reject the calls based on fuzzy logic control. Transmission control is provided thru Distributed Dynamic Channel allocation(DDCA) using co-operative negotiation of M ulti-Agent System. We demonstrate the efficiency of the proposed framework model by determining call dropping probability and call blocking probability.

A Temporal Database Compression with Differential Method

days it is very tedious job to keep files for personal as well as commercial computing. There are various type of compressing technique used, but one step ahead from them available technique is described here. Almost every application the backend used is database. That why my technique is dedicated to this type of databases. In this proposed technique we consider every type of compression, but when comes to date and time based database, not much compression technique deals with it. For text type compression there are many techniques same for images. But here we are proposing mainly for time and date type data bases. The practical use for this compression may useful for LIC policies, Stock Exchange, Railways Reservations databases etc. It may also useful for Employees working in a firm, maintaining daily database for salary purposes like Time in and Time out. For this type of database the proposed technique will give a big amount of compressions than any other type of techniques. We have techniques regarding database compression are character, memo, number, date, time compression which can work for individual fields in a database. In this paper main concentration has been given for time compressions. We suggested one example in tabular form on that our differential and time method has been applied.