Voice Traffic Performance in a Wireless LAN using the Point Coordination Function

Thumbnail Image

URL

Journal Title

Journal ISSN

Volume Title

Helsinki University of Technology | Master's thesis
Checking the digitized thesis and permission for publishing
Instructions for the author
Location:
P1 Ark S80

Authors

Date

2004

Department

Sähkö- ja tietoliikennetekniikan osasto

Major/Subject

Tietoliikennetekniikka

Mcode

S-72

Degree programme

Language

en

Pages

iii + 67 s. + liitt. 14

Series

Abstract

IEEE 802.11 (WLAN) has been designed primarily for non-real-time data applications with Distributed Coordination Function (DCF). For transmission of real-time data, the supplementary medium access protocol Point Coordination Function (PCF) is used, which resides on top of DCF and uses a centralized polling scheme. This thesis implements the basic Point Coordination Function algorithm in a time-driven simulation program written in C language, and evaluates the performance of voice transmission in a Wireless LAN with PCF supported. The evaluation covers the throughput, delay distribution, the frame loss rate, and compares the performance for two kinds of PCM payload length. The simulation results show that the proper superframe size should be approximately similar to the traffic interval, which results in good performance. Further, the simulation shows that long payload provides higher throughput and lower frame loss rate than short payload, but meanwhile, long payload brings longer access delay. When the number of VoIP mobile stations increases, the performance degrades dramatically. Therefore, PCF provides limited good service differentiation to the real-time applications.

Description

Supervisor

Häggman, Sven-Gustav

Thesis advisor

Hall, Michael

Keywords

WLAN, DCF, PCF, PCM, VoIP

Other note

Citation

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-2020120450536

Collections

[dipl] Teknillinen korkeakoulu / TKK