Single user TCP downstream throughput probability models in IEEE802.11b WLAN system

Abstract

Single User, Transmission Control Protocol Downstream Throughput (TCPDST) probability models in an IEEE802.11b WLAN have been developed, validated and evaluated for performance. Measurement of single user TCPDST were taken using Tamosoft throughput test while that of signal to noise ratio (SNR) were taken using inSSIDer 2.1. The Tamosoft throughput tests were conducted using different quality of service (QoS) traffic. These QoS traffic (which were sent through an infrastructure based network) correspond to different wireless multimedia tags. Measurements were taken in free space, small offices and open corridor environments. By assuming a normal distribution, single user TCPDST Cumulative distribution function (CDF) probability models were developed for different signal categories namely: (i) all the SNR considered, (ii) strong signals only, (iii) grey signals only and (iv) weak signals only. The models were validated and their performances evaluated using root mean square (RMS) errors. RMS errors were computed by comparing model predicted values with validation data. The RMS errors for single user CDF all signals model was 0.1466%. RMS errors for strong signals models, grey signals model and weak signals model respectively were 0.1466%, 0.6756% and 0.1233% indicating acceptable performances. All signals, strong signals, grey signals and weak signals CDF probability models predicted probabilities of obtaining TCPDST values greater than 5Mbps as 74.79%, 90.55%, 13.00% and 4.77% respectively while probabilities of obtaining TCPDST values less than 2Mbps were predicted as 4.91%, 0.00%, 18.98% and 52.41% respectively. These probability models will provide additional useful information needed to design efficient distributed data networks.
 Keywords: Throughput, TCP, WLAN, probability models

Performance Evaluation of A Peer-to-peer Wireless Ad-hoc Network

“…But on the average, it could be said that the plot shows a slowly increasing jitter with time. The findings here are in total agreement with [13,16].…”

“…Their results showed that 1EEE 802.11p performed better. A two types of single user models was developed in [16] for predicting transmission control protocol (TCP) downstream throughput in IEEE 802.11g wireless local area networks, for different signal to noise ratio (SNR) categories. They used Tamosoft throughput test tool to collect different SNRs in open corridor, free space and small offices.…”

Empirical Observation of Wireless Network Performance for Transmission Control Protocol (Tcp) Upstream and Downstream for Different Users Scenarios

“…The work done by [7], used NETSIM for simulation and analysis of LAN network performance implemented in CIT college campus network for realistic traffic scenarios and to study its performance metrics. In [8], empirical probability models for predicting TCP downstream throughput in WLAN system were presented. The paper contains information indicating the dependence of TCP downstream on SNR for various observed signal levels.…”

“…Papers on measuring and investigating TCP upstream dependence on SNR models that could predict TCP performance at various signal ranges and environments have been investigated. The investigations at real network time were done for IEEE 802.11b systems and the outcome indicates its importance as a tool in WLAN deployment as [developed in [8][9][10] [11]. The work done in [12], used UDP traffic to measure uplink and downlink signal strength from a network interface Card while monitoring the packet error rate at the data link layer and the throughput at the transport layer.…”

“…Using directional antennas can improve the performance of wireless networks by reducing interference and increasing signal strength but does not handle WLANs deployment considering SNR. Most of the works as seen in [8][9][14] [11], investigated TCP upstream and downstream throughput focusing on IEEE 802.11b WLAN system. The work presented in this paper followed the same research method used in [10] [14][15] but focused on IEEE 802.11g WLAN system instead because it has a vast deployment in University of Nigeria Nsukka wireless network (Lionet).…”