Wireless Communication

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).

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Debabrata Sarddar ¹, Shubhajeet Chatterjee ², Papri Mani ³, Pulak Mazumder ⁴, Sandip kr. Bala ¹, Utpal Biswas ¹, M. K. Naskar ¹

Affiliations
1 Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata – 700032, IN
2 Department of Electronics and Communication Engineering, Institute of Engg. & Managment College, saltlake, Kolkata-700091, IN
3 Department of Information Technology, West Bengal University of Technology, Kolkata-700064, IN
4 Department of Electronics and Telecommunication Engineering, Regent Education & Research Foundation, Barracpore, IN

Abstract

Due to rapid growth in IEEE 802.11 based Wireless Local Area Networks (WLAN), handoff has become a burning issue. A mobile node (MS) requires handoff when it travels out of the coverage area of its current access point (AP) and tries to associate with another AP. But handoff delays provide a serious barrier for such services to be made available to mobile platforms. Throughout the last few years there has been plenty of research aimed towards reducing the handoff delay incurred in the various levels of wireless communication. In this paper, we propose to reduce handoff latency for IEEE 802.11 wireless networks with map based on GPS. IEEE 802.11 uses 14 possible channels of which only the channels 1, 6 and 11 do not mutually overlap. As they are non-overlapping, the channels are expected to have a lower carrier-to-interference ratio (CI) compared to the other channels present under the same base station, which increases the channel‟s availability during handoff. Based on 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

Next Generation Wireless Systems (NGWS), Handoff, BS (Base Station), MS (Mobile Node), RSS (Received Signal Strength), IEEE802.11, CI Ratio.

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Debabrata Sarddar ¹, Shubhajeet Chatterjee ², Ramesh Jana ¹, Shaik Sahil Babu ¹, Utpal Biswas ³, M. K. Naskar ⁴

Affiliations
1 Department of Electronics and Telecommunication Engg, Jadavpur University, Kolkata – 700032, IN
2 Department of Electronics and Communication Engg, Institute of Engg. & Managment College, Saltlake, Kolkata-70009, IN
3 Jadavpur University, IN
4 E&ECE Department, IIT Kharagpur, IN

Abstract

Presently, 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. When a mobile station (MS) moves outside the range of its current access point (AP) it needs to perform a link layer handover. This causes data loss and interruption in communication. According to IEEE 802.11 link layer2 (L2) handoff performed in three phases – scanning, authentication and re-association. Scanning process causes 90% of the total handoff delay. Throughout the last few years so many researches had been done to reduce the hand off delay.Here we propose a new scanning technique in which we divide a cell in three sectors and thus reducing the number of APs to be scanned by fixing the neighbour APs with respect to each sector. This process effectively reduces the handoff latency.

Keywords

IEEE 802.11, Handoff Latency, GPS (Global Positioning System), Regression, Neighbor APs.

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