The Effect of Channel Fading on Providing Quality

Majlesi Journal of Electrical Engineering

مقاله 2، دوره 2، شماره 3، آذر 2008، صفحه 7-13   

نوع مقاله: Review Article

شناسه دیجیتال (DOI): 10.1234/mjee.v2i3.85

نویسندگان

Marzieh Varposhti؛ Naser-Movahhedinia Movahhedinia^*

چکیده

Transferring real-time traffic such as voice and video over wireless LAN network (WLAN) requires stringent delay and jitter requirements. One of the methods to provide QoS in this standard is Enhanced Distributed Channel Access (EDCA) which benefits form the concept of traffic categories. However, EDCA is a contention based method; therefore it can not guarantee strict QoS required by real-time services without proper network control mechanisms. One of the challenging problems in wireless networks is the failure of transmitting media due to fading. Normally the node does not differentiate between the media access collision and the channel failure. The performance of this method in case of fading channel has not yet been evaluated. In this paper, we analyze the effect of loss and delay caused by fading channel on EDCA performance. Then, we propose a modification to the media access scheme to elevate the performance against channel failures. Moreover an adjustment for the maximum number of retransmissions is proposed to maintain the delay and jitter requirements of the real-time traffic. The performances of the proposed methods are evaluated by simulations. 

کلیدواژه‌ها

EDCA؛ en؛ IEEE 802.11e؛ QoS channel fading

مراجع

[1] F. Cali; “IEEE 802.11 protocol: Design and

performance evaluation of an adaptive

backoff mechanism”, IEEE J. Select. Areas

Commun, Vol. 18, pp. 1774- 1786, Sept. 2000.

[2] G. Bianchi; “Performance analysis of the

IEEE 802.11 distributed coordination

function”, IEEE J. Select. Areas Commun,

Vol. 18, pp. 535 - 547, Mar. 2000.

[3] H. Wu, Y. Peng, K. Long, S. Cheng, and J.

Ma; “Performance of reliable transport

protocol over IEEE 802.11 wireless LAN:

Analysis and enhancement”, in INFOCOM

2002 - 21th Annual Joint Conference of the

IEEE Computer and Communications

Societies, Vol. 2, pp. 599 - 607, June 2002

[4] T. Bheemarjuna Reddy , John P. John , C. Siva

Ram Murthy; “Providing MAC QoS for

multimedia traffic in 802.11e based multihop

ad hoc wireless networks”, pp 153-184,

elsevier 2006

[5] L. Romdhani, Ni. Qiang, T. Turletti;

“Adaptive EDCF: enhanced service

differentiation for IEEE 802.11 wireless adhoc

Networks”, in: IEEE Wireless

Communications and Networking, Conference,

Vol. 2, pp 16-20, March 2003

[6] Wen-Yen Lin , Jung-Shyr Wu; “Modified

EDCF to improve the performance of IEEE

802.11e WLAN”, pp 1-8, elsevier 2006

[7] Wu Haitao, et.al; “IEEE 802.11e Enhanced

Distributed Channel Access (EDCA)

Throughput Analysis”,pp 223-226, IEEE

2006

[8] Mangold Stefan, Philips Research; “Analysis

of IEEE 802.11E for QoS support in wireless

LANs”, pp 40-49, IEEE Wireless

Communications , December 2003

[9] Zhifeng Tao and Shivendra Panwar;

“Throughput and Delay Analysis for the

IEEE 802.11e Enhanced Distributed

Channel Access ”, IEEE Transactions on

communications, Vol. 54, No. 4, pp 596-600,

APRIL 2006

[10] Hai Jiang, Ping Wang, and Weihua Zhuang;

“Enhanced QoS Provisioning in Distributed

Wireless Access ”, IEEE 2006

[11] Hongqiang Zhai1, Y. Younggoo Kwon2 and

Yuguang Fang1; “Performance analysis of

IEEE 802.11 MAC protocols in wireless

LANs”, Wirel. Commun. Mob. Comput., pp

917-931, Dec 2004;

[12] Hongqiang Zhai, Xiang Chen, Yuguang Fang;

“A call admission and rate control scheme

for multimedia support over IEEE 802.11

wireless LANs”, pp 451-460, springer 2006

[13] IEEE Draft Standard 802.11e/D13.0, Jan.

2005.

[14] 14T. S. Rappaport, Wireless Communications:

Principles and Practice, 2nd edition, Prentice

Hall, Desember 31, 2001.