The IUP Journal of Telecommunications
Delay-Sensitive Smart Polling in Dense IEEE 802.11n Network for Quality of Service

Article Details
Pub. Date : Feb, 2018
Product Name : The IUP Journal of Telecommunications
Product Type : Article
Product Code : IJTC11802
Author Name : H Vishalakshi Prabhu and G S Nagaraja
Availability : YES
Subject/Domain : Science & Technology
Download Format : PDF Format
No. of Pages : 13

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Abstract

In this paper, the polling mechanism of IEEE 802.11n standard is examined with the objective of reducing the delay induced by polling a large number of stations in crowded hotspot. This standard, also known as high speed Wireless Local Area Network (WLAN), is competent to become carrier Wi-Fi in the Evolved Packet Core (EPC). Scheduling algorithms are playing a major role in yielding QoS in high speed wireless networks of next generation. IEEE 802.11n standard has some support for Quality of Service (QoS)-based scheduling, but one that focuses on polling is not dealt with much in detail. Polling is a centralized scheduling which is initiated by the Access Point (AP) to poll user stations. Most of the proposed polling mechanisms introduce delay when the number of stations under a given access point increases. The aim of this paper is to introduce new polling algorithm based on two-level priority queues to reduce the polling delay in a crowded WLAN hotspot. This in turn assures the QoS guarantees for delay-sensitive applications. The new algorithm is named as Smart_Poll. The paper also discusses the performance estimation of the proposed smart polling by comparing it with traditional polling.


Description

High speed WLAN hotspot is the latest trend in accessing Internet anytime and anywhere which is based on advances in wireless communication. The Working Group under the Institution of Electrical and Electronic Engineers (IEEE) has framed a standard for WLANs and designated it as IEEE 802.11. Starting from the earliest IEEE 802.11b to the latest IEEE 802.11ac, there are versions of WLAN with varying data rates. But IEEE 802.11n relies on Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Inputs Multiple Outputs (MIMO) to provide high speed data at 600 Mbps peak and hence holds special interest among busy clients (Federico et al., 2015).

Some of the design goals of IEEE 802.11 architecture are easy deployment, portability, high speed data rate, less Bit Error Rate (BER), compatibility with widely deployed wired Ethernet (IEEE 802.3) standards and premium service. The earlier standards were not supporting QoS to applications, but IEEE 802.11e and IEEE 802.11n have some support for non-real and real-time data. These circumstances promote IEEE 802.11n to compete with other wireless technologies like Long Term Evolution (LTE), 4G and 5G. Certainly, the diverse applications demand higher QoS in uplink and downlink directions. The newer generations of WLAN aim at satisfying QoS needs of real-time applications like video and audio. These flows possess stringent requirements in terms of delay, loss and rate. In practice, delivering these services over unlicensed wireless environment requires assured features which are missing in the primitive IEEE 802.11 standard. All latest WLAN devices have inherited the essential features of original IEEE 802.11 standard which was designed primarily for simple data applications without taking into account the differentiation of traffic (IEEE, 2012). Hence to provide QoS, they need to implement efficient scheduling either at data-link or network layer.


Keywords

Telecommunications Journal,Access Point (AP), IEEE 802.11n, Quality of Service (QoS), Smart_Poll, Station (STA), Wireless Local Area Network (WLAN).