|1 Obstacle Management in VANET using Game Theory and Fuzzy Logic Control, Yousaf Saeed, Suleman Aziz Lodhi, Khalil Ahmed
Mountainous roads where probability of land sliding exists, causes hurdles not only in the traffic flow but generate various traffic problems in the form of congestion, high accidents rate and wastage of time. The purpose of this paper is to minimize traffic congestion and wait time of the vehicles. Obstacle management is analyzed in Vehicular Adhoc Network and a mechanism is devised by using a cooperative game approach. Conflict between vehicles has been taken into consideration on one of the roads of mountainous area and two vehicles are considered to play the game. Possible actions, information set and strategies have been defined and payoffs are calculated. Finally, the outcome is achieved in the form of minimum time required for smooth flushing of the vehicles while fuzzy logic control has been used for simulation. It is found that by applying game theory in VANETs and fuzzy logic control for simulation, results can be achieved quite well in the form of minimizing traffic congestion and reduced wait time. The approach makes the traffic regularized not only in the mountainous areas but in urban and rural areas as well upon facing road hurdles. The involvement of Game Theory in VANETs makes it very useful approach in dealing with obstacle management.
|2 Implementation of Object Tracking for Real Time Video, Rajesh Chhikara, Sunil Kumar, Gopinath S
Real-time tracking of object boundaries is an important task in many vision applications. Here we propose an approach to implement the level set method. This approach does not need to solve any partial differential equations (PDFs), thus reducing the computation dramatically compared with optimized narrow band techniques proposed before. With our approach, real-time level-set based video tracking can be achieved.
|3 Improving Performance of TCP in Wireless Environment using TCP-P, Ranjeet Vasant Bidwe and Amar Buchade
Improving the performance of the transmission control protocol (TCP) in wireless environment has been an active research area. Main reason behind performance degradation of TCP is not having ability to detect actual reason of packet losses in wireless environment. In this paper, we are providing a simulation results for TCP-P (TCP-Performance). TCP-P is intelligent protocol in wireless environment which is able to distinguish actual reasons for packet losses and applies an appropriate solution to packet loss. TCP-P deals with main three issues, Congestion in network, Disconnection in network and random packet losses. TCP-P consists of Congestion avoidance algorithm and Disconnection detection algorithm with some changes in TCP header part. If congestion is occurring in network then congestion avoidance algorithm is applied. In congestion avoidance algorithm, TCP-P calculates number of sending packets and receiving acknowledgements and accordingly set a sending buffer value, so that it can prevent system from happening congestion. In disconnection detection algorithm, TCP-P senses medium continuously to detect a happening disconnection in network. TCP-P modifies header of TCP packet so that loss packet can itself notify sender that it is lost.This paper describes the design of TCP-P, and presents results from experiments using the NS-2 network simulator. Results from simulations show that TCP-P is 4% more efficient than TCP-Tahoe, 5% more efficient than TCP-Vegas, 7% more efficient than TCP-Sack and equally efficient in performance as of TCP-Reno and TCP-New Reno. But we can say TCP-P is more efficient than TCP-Reno and TCP-New Reno since it is able to solve more issues of TCP in wireless environment.
|4 Towards Seamless TCP Congestion Avoidance in Multiprotocol Environments, Martin Hruby, Michal Olsovsky, Margareta Kotocova
In this paper we explore the area of congestion avoidance in computer networks. We provide a brief overview of the current state of the art in congestion avoidance and also list our extension to the TCP congestion avoidance mechanism. This extension was previously published on an international forum and in this paper we describe an improved version which allows multiprotocol support. We list preliminary results carried out in a simulation environment. New introduced approach called Advanced Notification Congestion System (ACNS) allows TCP flows prioritization based on the TCP flow age and priority carried in the header of the network layer protocol. The aim of this approach is to provide more bandwidth for young and high prioritized TCP flows by means of penalizing old greedy flows with a low priority. Using ACNS, substantial network performance increase can be achieved.
|5 Spur Reduction Of MB-OFDM UWB System using CMOS Frequency Synthesizer, G. Karunya Elizabeth and S.P.Valan Arasu
As Technology progress deeper into submicron CMOS, traditional analog circuits face problems that are not to be solved purely by analog innovations. Instead, new architectures are being proposed which take advantages of the relatively cheaper of the digital circuits to augment or improve the diminishing performance of the analog circuitry. The conventional approach performs the design of 14 bands CMOS frequency synthesizers with spur reduction for MB-OFMD for analog circuits which have high distortions and noise. My proposed work is to replace the analog input PLL into All Digital PLL with spur reduction. Then the frequency mixing architecture alleviates harmonics mixing and pulling to diminish spur generation. The simulation is performed using Model SIM and the implementation using Microwind to diminish spur reduction.
|6 Circular Patch Antenna Performance using EBG Structure, A. Bendaoudi and R. Naoum
Electromagnetic Band-Gap (EBG) structures are a popular and efficient technique for microwave applications. EBG may be combined with microstrip antenna to increase the diversity gain, the radiation efficiency and/or to suppress surface waves, to reduce the side lobes of the radiation pattern and to increase the bandwidth. In this paper, two different structures will be presented and discussed, which involve: (1) EBG structure fed by circular patch antenna, and (2) circular patch antenna surrounded by one row of EBG structure. The influence of the EBG structure on the radiation patterns is investigated. The effect of the surface waves is also considered. Finally, the reduction of the side lobes of the radiation pattern to increase the bandwidth is presented.
|7 An Improved Design of Contract Net Trust Establishment Protocol, Aarti Singh, Dimple Juneja
Contract Net Protocol (CNP) is FIPA standardized high level communication protocol which specifies the way software agents should follow while communicating. However it lacks methods for ensuring trust and reliability of the agents participating in the communication. In an earlier paper authors proposed a variation of CNP involving trust establishment feature into it, termed as Contract Net Trust Establishment Protocol (CNTEP). However, efficient communication can not be ensured unless the communicating counterpart is reliable. This fact provided the motivation for the present work, which extends CNTEP and incorporates reliability computation component in it.
|8 Packet Loss and Overlay Size Aware Broadcast in the Kademlia P2P System, Zoltán Czirkos, György Bognár and Gábor Hosszú
Kademlia is a structured peer-to-peer (P2P) application level network, which implements a distributed hash table (DHT). Its key-value storage and lookup service is made efficient and reliable by its well-designed binary tree topology and dense mesh of connections between participant nodes. While it can carry out data storage and retrieval in logarithmic time if the key assigned to the value in question is precisely known, no complex queries of any kind are supported. In this article a broadcast algorithm for the Kademlia network is presented, which can be used to implement such queries. The replication scheme utilized is compatible with the lookup algorithm of Kademlia, and it uses the same routing tables. The reliability (coverage) of the algorithm is increased by assigning the responsibility of disseminating the broadcast message to many nodes at the same time. The article presents a model validated with simulation as well. The model can be used by nodes at runtime to calculate the required level of replication for any desired level of coverage. This calculation can take node churn, packet loss ratio and the size of the overlay into account.