Informatics Publishing Limited

P. P. Edwin Winston ¹, K. S. Shaji ²

Affiliations
1 Department of Electronics and Telecommunication Engineering, Sathyabama University, Chennai, IN
2 Rajas International Institute of Technology For Women-RIITW, Nagercoil, IN

Abstract

Mobile WiMAX, the enhanced version of the IEEE 802.16 standard with mobility support, defines the implementation of hard handover is mandatory. Being a break before make technique, the HHO concept in MWiMAX suffers from a lengthy “inter-handover” CDT that could lead to unwanted hazards like packet losses, call disruptions or even call drops, while on the move. This occurs in the actual handover phase, when an MS terminates the connection with the SBS and tries to set-up connections with the selected TBS. In MWiMAX, data, voice and multimedia contents are intermixed and each requires different mechanisms for its transmission, particularly during handover. So, such a lengthy CDT may cause serious service disruptions in case of real-time high-speed delay-sensitive voice and streaming multimedia applications in MWiMAX networks. To solve this problem without many changes to 802.16e equipments, we propose an enhanced link-layer QoS aware handover scheme-Passport Handover to accelerate handover process. We also propose a connection CID assignment strategy to avoid confliction of CIDs of handing over services with that of ongoing services in the target BS. Finally we have evaluated the performance using OPNET Modeler.

Keywords

WiMAX, Handover, OPNET Modeler.

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N. Prabakaran ¹, K. S. Shaji ²

Affiliations
1 Department of Electronics & Telecommunication Engineering, Sathyabama University, Chennai, 600119, Tamilnadu, IN
2 Rajas International Institute of Technology for Women, Nagercoil, IN

Abstract

The emergence of several radio technologies such as Bluetooth, and IEEE 802.11 operating in the 2.4 GHz unlicensed ISM frequency band may lead to signal interference and result in significant performance degradation when devices are co-located in the same environment. In the normal mode of operation of co located Bluetooth piconets, nodes in different piconets transmit independently of each other, and thus in band co-channel interference is certain to occur from time to time. IEEE 802.11 and Bluetooth, these two operating in the unlicensed 2.4 GHz frequency band are becoming more and more popular in the mobile computing world. The number of devices equipped with IEEE 802.11 and Bluetooth is growing drastically. Result is the number of co-located devices, say within 10 meters, grown to a limit, so that it may causes interference issues in the 2.4 GHz radio frequency spectrum. In this paper, we investigate the interference issues of 2.4 GHz frequency band.

Keywords

Bluetooth, IEEE 802.11b, Interference, WLAN.

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M. S. Godwin Premi ¹, K. S. Shaji ²

Affiliations
1 Department of Electronics and Telecommunication Engineering, Sathyabama University, Chennai, Tamil Nadu, IN
2 Rajaas International Institute of technology for Women, Nagercoil, Tamil Nadu, IN

Abstract

Set routing is one of the methods used for maximum data collection in mobile wireless sensor networks. In this routing the entire network is divided into many sets. Route maintenance is the major problem with any routing algorithm in mobile wireless sensor networks. Because of mobility and node failures the routes keeps on changing. The problem with the route maintenance in set routing can be overcome by using fuzzy sets. This fuzzy set provides the quality of the old route as well as the necessity for the new route. This is given along with the routing table and is written on the sink node or base station. This reduces the individual node overhead. Simulation is performed with OMNET++ simulator. Result shows the effectiveness of the fuzzy set in route maintenance and new route determination.

Keywords

Mobile Nodes, Neighbouring Nodes, Set Routing, Wireless Sensor Networks.

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