Page 2 Lecture Notes in Computer Science 2865 Edited by G. Goos ...

Analyzing Split Channel Medium AccessControl Schemes with ALOHA Reservation ⋆Jing Deng 1 , Yunghsiang S. Han 2 , and Zygmunt J. Haas 31 The CASE Center and the Dept. of Electrical Engineering and Computer Scienceat Syracuse University, Syracuse, NY, USAjdeng01@ecs.syr.edu2 The Dept. of Computer Science and Information Eng.National Chi Nan University, Taiwan, R.O.C.yshan@csie.ncnu.edu.tw3 School of Electrical & Computer Engineering at Cornell UniversityIthaca, NY, USAhaas@ece.cornell.eduAbstract. In order to improve the throughput performance of MediumAccess Control (MAC) schemes in wireless communication networks,some researchers proposed to split the single shared channel into twosubchannels: a control subchannel and a data subchannel. The controlsubchannel is used for access reservation to the data subchannel overwhich the data packets are transmitted, and such reservation can bedone through the use of the dialogues such as RTS/CTS (Ready-To-Send/Clear-To-Send) dialogue. In this paper, we evaluate the maximumachievable throughput of split-channel MAC schemes that are based onRTS/CTS dialogues with pure ALOHA contention resolution mechanism.We derive and calculate numerically the probability density function(pdf) of the contention resolution periods on the control subchannel.We then apply these results to calculate the throughput of the splitchannelMAC schemes, which we then compare with the performance ofthe corresponding single-channel MAC schemes. Our results show that,when radio propagation delays are negligible, the maximum achievablethroughput of the split-channel MAC schemes is lower than that of thecorresponding single-channel MAC schemes in the scenarios that we havestudied. Consequently, our results suggest that splitting the single sharedchannel of the MAC scheme in a wireless network should be avoided.Simulation results are presented to support our analytical results.⋆ This work was supported in part by the SUPRIA program of the CASE Centerat Syracuse University, by the National Science Council of Taiwan, R.O.C., undergrants NSC 90-2213-E-260-007 and NSC 91-2213-E-260-021, and by the DoD MultidisciplinaryUniversity Research Initiative (MURI) program administered by theOffice of Naval Research under grant number N00014-00-1-0564. Part of Han’s workwas completed during his visit to the CASE Center and Dept. of Electrical Engineeringand Computer Science at Syracuse University, USA.S. Pierre, M. Barbeau, and E. Kranakis (Eds.): ADHOC-NOW 2003, LNCS 2865, pp. 128–139, 2003.c○ Springer-Verlag Berlin Heidelberg 2003