Informatics Publishing Limited

N. Nagarajan , Uma Maheswari , V. Mohan , S. N. Suresh

Abstract

An attempt has been made to investigate the occurrence and distribution of arbuscular mycorrhizal (AM) fungi in association with the ischolar_mains and rhizosphere soils of 46 different plant species belonging to 25 families grown in Koochi Hills, Western Ghats, Coimbatore district, Tamil Nadu. It was found that all the samples had AM fungal colonization in the form of vesicular, arbuscular and hyphal structures in the ischolar_mains and spores from the rhizosphere soils but there was variation in per cent ischolar_main colonization and soil spore population. Total of 18 different AM fungi belonging to four genera viz., Acaulospora, Gigaspora, Glomus and Scutellospora were recorded from the rhizosphere of different plant species. Among them, the genus Glomus was found most dominant group of AM fungi. In this study, AM fungal association was reported for the first time in some of the plants of the families such as Araceae, Caryophyllaceae, Asteraceae, Chenopodiaceae, Elaeginaceae, Euphorbiaceae, Poaceae, Nyctaginaceae, Oleaceae, Onagraceae, Polygonaceae, and Portulacaceae, which were reported to be non-mycorrhizal.

Keywords

Arbuscular mycorrhizal Fungi, Western Ghats, Symbiotic Relationship, Soil Spore
Population

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S. Gopinath ¹, N. Nagarajan ²

Affiliations
1 Anna University, Chennai, IN
2 Department of ECE, Coimbatore Institute of Engineering and Technology, Coimbatore, IN

Abstract

Background/Objectives: Due to the presence of mobility, the nodes may move out of the coverage region. Mobility of nodes causes network partition. This will lead to heavy overhead and less packet forwarding ratio. Methods/Statistical Analysis: In this research work, Residual Energy based Reliable Multicast Routing (RERMR) is proposed to increase the packet forwarding rate based on optimized multicast backbone construction. It consists of following phases. In first phase, the multicast backbone is constructed based on trustable loop and trust factors. The backbone is maintained by means of cluster group members. If the cluster head is not responding to cluster members or other cluster head, the secondary cluster leader checks whether it attains the latency threshold and announces that as a cluster head. Reliable path is calculated based on stability of links and residual energy is saved based on signal strength and distance. Results: For simulation, the network simulator tool (NS 2.34) is used. The QoS parameters and the proposed parameters are taken for analysis for performance of existing and proposed work. Based on the simulation results, the proposed work achieves better performance than previous protocols in terms of path reliability rate, network stability rate, end to end delay, end to end transmission and communication overhead.

Keywords

Communication Overhead, End to End Delay, End to End Transmission Multicast, Network Stability Rate, Optimized Multicast Backbone, Packet Forwarding Ratio, Path Reliability Rate, Reliable Path, Residual Energy

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D. Satish Kumar ¹, N. Nagarajan ²

Affiliations
1 Kalaignar Karunanidhi Institute of Technology, Coimbatore-641402, Tamil Nadu, IN
2 Coimbatore Institute of Engineering and Technology, Coimbatore-641109, Tamilnadu, IN

Abstract

Two different relay modes are defined in IEEE 802.16j WIMAX standard: transparent mode and non-transparent mode. The non transparent mode is used to extend the coverage area of base stations, where low cost relay station of equal capacity as that of base station is placed at suitable position. Time taken to accept mobile stations and Bandwidth allocation are main problems in non transparent mode. The Transparent mode is used to increase the capacity of the base station within the coverage area of base station.

In this we have studied the IEEE 802.16j standard multi hop relay WIMAX networks. We have used relay stations to extend the coverage of base stations. We have also analyzed the throughput between mobile stations with in the coverage area and outside coverage area of base stations. We have simulated the IEEE 802.16j transparent and non transparent mode multi hop WIMAX relay networks using NCTUns Tool.

Keywords

IEEE 802.16j, Relay Modes, Transparent Mode, Non-Transparent Mode, WIMAX, NCTUns, Throughput etc.

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D. Satish Kumar ¹, N. Nagarajan ²

Affiliations
1 Kalaignar Karunanidhi Institute of Technology, Coimbatore-641402, Tamil Nadu, IN
2 Coimbatore Institute of Engineering and Technology, Coimbatore-641109, Tamilnadu, IN

Abstract

An Adaptive Network Topology Acquisition (A-NTA) Algorithm for IEEE 802.16j non transparent mode relay networks is presented in this paper. We have implemented this algorithm in NCTUns open source network simulator. In this algorithm the process of setting channel ID for mobile stations, and time taken to accept a new mobile station are mainly focused. The mobile stations which are in the coverage area of base station are given first preference, and those outside coverage area are assigned channel ID through relay stations. Two ID’s are set for each mobile station: Basic channel ID [1, 2, 3….] and Primary Channel ID [256, 257, 258…]. Mobile stations are first accepted by base stations, to allocate band width. We have studied the time taken to accept mobile stations. The results show that, base station takes 0.0096613 sec to accept one mobile station (inside coverage area) and it takes 0.065001 sec to accept one mobile station (outside coverage area)- through a relay station . Here 0.085308 sec is spend to accept one relay station.

Keywords

A-NTA Algorithm, IEEE 802.16j, Non-Transparent Mode, Relay Station, Channel ID, NCTUns etc.

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M. Sadish Sendil ¹, M. Kavitha ¹, U. Kaleelurrahaman ², S. Karthik ¹, N. Nagarajan ³

Affiliations
1 SNS College of Technology in Department of Computer Science and Engineering, Coimbatore, IN
2 SNS College of Technology in Department of Information Technology, Coimbatore, IN
3 Coimbatore Institute of Engineering and Technology, Coimbatore, IN

Abstract

Problem statement: In the last years, we have seen that the use of P2P applications has increased significantly and currently they represent a significant portion of the Internet traffic. In consequence of this growth, P2P traffic characterization and identification are becoming increasingly important for network administrators and designers. Also increasing amount of P2P services not only consuming a lot of bandwidth but also influencing the performance of other business. Another difficulty in identification of traffic in P2P is that P2P applications have the ability to disguise their existence through the use of arbitrary ports and explicitly try to camouflage the original traffic in an attempt to go undetected. In this paper we have analyzed different type of identification methods and compared the efficiency in each method. Approaches: 1. P2P traffic identification using Cluster analysis which seek five traffic discriminators and applies cluster analysis to identify P2P traffic. 2. P2P traffic identification based on double layer characteristics which identify traffic based on flow characteristics and payload characteristics. 3. Transport layer heuristic identification in which P2P traffic flows are identified by analyzing the statistical properties of the flows and their behavior characteristics. 4. Payload-based IP traffic identification packet payloads are analyzed to determine whether they contain specific signatures of known applications. Results: After analyzing each model we find out that there are both advantages and limitation in it. We have simulated those models and compared with each other. Conclusion and Future work: With the widely adoption of the P2P, the method for the control and the management to the P2P applications has become a research hotspot. In this paper we analyse different methods to identify the traffic in P2P application. In future we try to build a new algorithm which combines the best capabilities of the analyzed approaches.

Keywords

Cluster Analysis, Flow Characteristics, Payload Characteristics, Traffic Identification.

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M. Sadish Sendil ¹, N. Nagarajan ²

Affiliations
1 Department of Computer Science and Engineering, SNS College of Technology, Sathy NH, Coimbatore, Tamilnadu, IN
2 Coimbatore Institute of Information and Engineering Technology, Coimbatore, Tamilnadu, IN

Abstract

Peer-to-Peer (P2P) system has become one of the hottest research topics, its excellent characteristics of fully decentralized control and self-organizing make it attractive for some particular applications. Routing algorithm has great influence in P2P applications. Current routing algorithm concentrates on creating well organized network architecture to improve the routing performance. However, for each routing procedure, system returns location information of the requested file only and the characteristics of system workload are considered. Routing performance is critical for P2P networks to achieve high performance. Using sandwich method, the HDHTR and SDHTR are combined based on the following criteria: 1. creating a P2P ring where routing tasks are first executed in lower level ring before they go to higher level thus reducing routing overhead. 2. A super node based routing algorithm which reduce the average routing latency and cost. Hence it reduces the routing overhead and average routing latency, which thereby reduce the traffic.

Keywords

Peer to Peer, Dynamic Hash Table, Hierarchical DHT Routing, Super Node DHT Routing.

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M. Sadish Sendil ¹, N. Nagarajan ²

Affiliations
1 Department of Computer Science and Engineering, SNS College of Technology, Sathy NH, Coimbatore, Tamilnadu, IN
2 Coimbatore Institute of Information and Engineering Technology, Coimbatore, Tamilnadu, IN

Abstract

Peer to Peer network has become one of the most important areas while sharing the information in the global world. When we can share the information in the p2p network, traffic is the major problem. We can analyze the traffic theoretically which are associated with broadcasting. For theoretical analysis, we propose and evaluate the probability based schemes like Uniform Probability, Dropped Probability, Dropped Message, Triangle Based and Biased Forwarded to alleviate traffic load on broadcasting networks. Reducing redundant traffic is a natural approach to alleviate the high traffic problem without compromising the reachability of messages. Some of the schemes can significantly reduce the whole network traffic with little or no cost on reachability and latency of messages. And also we proposed the multi-backup routing method that makes use of redundant traffic to enable more search results to reach a searcher.

Keywords

P2P, UPBS, DPBS, DMBS, TBS, BFS.

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B. Kaarthick ¹, V. J. Yeshwenth ², P. M. Sudarsan ², N. Nagarajan ³, Rajeev ⁴

Affiliations
1 Network System Design Center, Sri Krishna College of Engineering and Technology, Coimbatore, IN
2 University of Texas at Dallas, US
3 Coimbatore Institute of Eng. and Information Technology, Coimbatore, IN
4 Wipro Technologies, IN

Abstract

IEEE 802.16e, a broadband wireless access technology that provides high speed internet access and multimedia services has seen very significant growth in recent times. With the due rapid deployment of WiMAX, there would be a growing demand for efficient support of voice applications. The performance of Voice over IP services depends on a proper scheduling algorithm combined with a proper Voice encoder scheme. The contribution of this work is two fold. The first is that we present an efficient scheduling algorithm that can be used for VoIP services in IEEE 802.16e. We then implement the algorithm in various CODECS and compare the performance of the codec's i.e.G.728, G.711, G.723, G.729, G.726, GSM-EFR, GSM-HR under similar load conditions for Interactive voice over WiMAX by enabling the Speech Activity Detection (SAD). We analyze the system throughput and delay to evaluate the performance of our algorithm and the primary metrics that were used in the comparison for choosing the right vocoders for the algorithm were Jitter, MOS, and packet end to end delay.

Keywords

QoS, vocoders, Jitter, VoIP, MOS.

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