Informatics Publishing Limited

Debabrata Sarddar ¹, Shubhajeet Chatterjee ², Pulak Mazumder ³, Kalyan Kumar Das ⁴, Sougata Chakraborty ⁵, Milton Samadder ⁶, Jayanta Kumar Bagchi ⁷, Kunal Hui ⁸

Affiliations
1 Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata – 700032, IN
2 Department of Electronics and Communication Engineering, Institute of Engg. & Management College, Saltlake, Kolkata-700091, IN
3 Department of Electronics and Telecommunication Engg, Regent Education & Research Foundation, Barracpore, IN
4 Cognizant, IN
5 IBM (Pune), IN
6 Department of IT in Bankura Unnayani Institute of Engineering College, IN
7 Electronics and Communication Department in Bankura Unnayani Institute of Engineering College, IN
8 L&T (Mumbai), IN

Abstract

Now a day, IEEE 802.11 based wireless local area networks (WLAN) have been widely deployed for business and personal applications. The main issue regarding wireless network technology is handoff or hand over management. The Quality of Service (QoS) is improved when the handoff is performed successfully and as frequently as possible without being perceptible to the users. Thus, it is required to prioritize the handoff request so as to minimize the blocking probability of handoff calls. The minimization of handoff failure due to call blocking is an important issue of research. For the last few years plenty of researches had been done to reduce the handoff failure. In this paper, we propose a hybrid channel allocation scheme which would effectively reduce the handoff call blocking probability. A handoff call queuing priority scheme has also been proposed to reduce forced call termination and hence enhance the performance of the system. Simulation results yield that the proposed mechanism outperforms the fixed channel assignment technique.

Keywords

Handoff Request, Hybrid Channel Allocation, Priority Schemes, Queuing.

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Debabrata Sarddar ¹, Shubhajeet Chatterjee ², Pulak Mazumder ³, Sougata Chakraborty ⁴, Jayanta Kumar Bagchi ⁵, Kunal Hui ⁶, Kalyan Kumar Das ⁷, Milton Samadder ⁸

Affiliations
1 Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata – 700032, IN
2 Department of Electronics and Communication Engineering, Institute of Engineering & Management College, Saltlake, Kolkata-700091, IN
3 Department of Electronics and Telecommunication Engineering, Regent Education & Research Foundation, Barracpore, IN
4 IBM (Pune), IN
5 Electronics and Communication Department in Bankura Unnayani Institute of Engineering College, IN
6 L&T (Mumbai), IN
7 Cognizant, IN
8 Department of IT in Bankura Unnayani Institute of Engineering College, IN

Abstract

IEEE 802.11b networks find unlimited applications. While roaming through an access points, a mobile node (MS) is frequently required to carry out a link layer handover. This mechanism causes a user intercept able connection loss and breaks in time-sensitive communication, especially when a network layer handover follows the link layer handover. In this paper, we propose a method to reduce handoff latency for IEEE 802.11b wireless networks with the help of Neighbor Graphs (NG), pre-scanning mechanisms and using a GPS based server which predetermines the next probable AP a mathematical techniques. IEEE 802.11 consist of11 channels among which the channels 1, 6 and 11 do not mutually overlap. The non overlapping channels are expected to have a lower carrier-to-interference (CI) ratio as compared to the other channels in attendance to the same base station, which increases the channel‟s accessibility during handoff. Based on the NG pre-scanning mechanism and next AP prediction using the GPS, when handoff criterions have been met, we design an algorithm to first scan the channels 1, 6 and 11, if present under the next Access Point (AP), to reduce the scanning delay. We also introduce pre-authentication mechanism, which will effectively reduce the message processing delay.

Keywords

Handoff, Neighbor Graph, Selective Channel Scanning Mechanism, Carrier-To-Interference (CI) Ratio, Global Position Systems (GPS).

Full Text

     

Debabrata Sarddar ¹, Shubhajeet Chatterjee ², Sougata Chakraborty ³, Jayanta Kumar Bagchi ⁴, Kunal Hui ⁵, Kalyan Kumar Das ⁶, Milton Samadder ⁷, Pulak Mazumder ⁸

Affiliations
1 Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata – 700032, IN
2 Department of Electronics and Communication Engineering, Institute of Engineering & Management College, Saltlake, Kolkata-700091, IN
3 IBM (Pune), IN
4 Department of Electronics and Communication Department in Bankura Unnayani Institute of Engineering College, IN
5 L&T (Mumbai), IN
6 Cognizant, IN
7 Department of IT in Bankura Unnayani Institute of Engineering College, IN
8 Department of Electronics and Telecommunication Engineering, Regent Education & Research Foundation, Barracpore, IN

Abstract

In satellite communication network, low earth orbit (LEO) satellite has become more popular than geostationary earth orbit satellite (GEO) due to their low propagation delay and low power requirements. During the course of movement of the LEO satellite, the area covered by its spot-beam (the footprint region of a satellite is divided into a number of clusters of cells which is known as spot-beam) is changing very rapidly. Thus the handover of connections from one spot-beam to other spot-beam is required. But their high relative speed and random direction of motion provide a serious barrier for such services to be made available to wireless communication. Throughout the last few years a plenty of researches had been done in this field of satellite handover management, but the problem remains unsolved. In this paper we are going to propose a new adaptive channel allocation scheme for efficient utilization of resources (channels) in handover and new channel allocation in LEO Satellite communication. We have divided the total footprint region in three sections according to the traffic load of different spot-beams (i.e. Urban Areas, Suburban Areas and Rural Areas) and for each section we have assigned different channel allocation techniques according to their traffic loads. This approach reduces the unnecessary complexity and unnecessary reservation of resources (channels) which in turn reduces the complexity of the communication network.

Keywords

Footprint, LEO, Channel Allocation, Spot-Beam, BS (Base Station).

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