Academic Journals Database
Disseminating quality controlled scientific knowledge

Measurement Based Link Level Investigation of IEEE 802.11g Channels

Author(s): Shaoen Wu | Saaˆd Biaz

Journal: International Journal of Computer Networks & Communications
ISSN 0975-2293

Volume: 3;
Issue: 2;
Start page: 1;
Date: 2011;
VIEW PDF   PDF DOWNLOAD PDF   Download PDF Original page

Keywords: Wireless Network | Measurement | IEEE 802.11

Assessing channel conditions is critical to routing and MAC protocols. But, this task is challenging due tothe highly dynamic nature of wireless channels and the characteristic differences between indoor andoutdoor environments. This paper presents observations and analysis from extensive measurements onIEEE 802.11g channels indoor and outdoor. The experiments are designed to investigate the channeldynamics through metrics such as successful frame delivery rate, loss rate, and Signal- to-Noise Ratioon IEEE 802.11 networks. The objective of this work is to reveal the interaction between these metricsand their variations in time and space.This paper makes the following observations. Frame delivery rate for fixed stations fluctuates over time inmost scenarios. Statistics over large time intervals get bursty and do not provide valuable informationabout channel conditions. Generally, Signal- to-Noise Ratio (SNR) varies widely over time even forfixed stations. However, the SNR remains stable for micro time scales. As a consequence, the framedelivery does not strongly correlate with SNR. Another obs er vat ion i s t h a t indoor and o u t d o o rrequire different sampling intervals to measure valuable frame loss rate. If sent at a favourable time, aset of frames is likely to be delivered successfully continuously. Although the intermediate distribution ofthe intervals between consecutive losses varies wildly for different transmission rates (modulations),most of these intervals are less than 5 ms regardless of the rate and location.
Why do you need a reservation system?      Save time & money - Smart Internet Solutions