DocumentCode :
1357754
Title :
A new adaptive MAC layer protocol for broadband packet wireless networks in harsh fading and interference environments
Author :
Acampora, Anthony S. ; Krishnamurthy, Srikanth V.
Author_Institution :
Center for Wireless Commun., California Univ., San Diego, La Jolla, CA, USA
Volume :
8
Issue :
3
fYear :
2000
fDate :
6/1/2000 12:00:00 AM
Firstpage :
328
Lastpage :
336
Abstract :
A new medium-access protocol is proposed for sharing a high-speed radio channel among a number of small wireless packet-access units, some of which may be stationary and some of which may be within moving vehicles. Such a system could provide fixed-point pedestrian and remote users with wireless access to CPU and database resources of an underlying asynchronous transfer mode (ATM) wireline network, essentially extending the ATM bandwidth-upon-demand interface directly to the wireless units and enabling delivery of multimedia services (albeit at the lower peak rate afforded by the radio channel). A primary goal of the proposed medium-access protocol is the pre-delivery of a signal from each packet-access unit as needed to rapidly compute the weights needed by a base station´s adaptive array processor or a space-time processor, thereby protecting the packet flow in each direction from the effects of both multipath propagation and adjacent channel interference arising in neighboring radio cells. An impairment-robust direct sequence spread-spectrum-based polling signal is invoked to stimulate a pilot tone from a given remote immediately prior to packet transfer in either direction, thereby permitting the base station to determine a good set of antenna element combining or power splitting weights to be used for that packet. Reasonable approximations are invoked to study the performance of the proposed protocol and the link utilization efficiency and average message delay are found. By proper choice of protocol parameters, a radio resource utilization efficiency of about 95% is readily achieved. The accuracy of the approximations is confirmed by extensive computer simulations
Keywords :
access protocols; adaptive systems; adjacent channel interference; asynchronous transfer mode; broadband networks; cellular radio; fading channels; multimedia communication; multipath channels; packet radio networks; spread spectrum communication; ATM wireline network; CPU resources; DS-SS polling signal; adaptive MAC layer protocol; adaptive array processor; adjacent channel interference; antenna element combining; approximations; asynchronous transfer mode; average message delay; bandwidth-upon-demand interface; base station; broadband packet wireless networks; computer simulations; database resources; direct sequence spread-spectrum; fixed-point pedestrian users; harsh fading environment; harsh interference environment; high-speed radio channel sharing; link utilization efficiency; medium-access protocol; moving vehicles; multimedia services; multipath propagation; neighboring radio cells; packet flow protection; pilot tone simulation; power splitting weights; protocol parameters; radio resource utilization efficiency; remote users; space-time processor; wireless packet-access units; Access protocols; Adaptive arrays; Asynchronous transfer mode; Media Access Protocol; Multimedia databases; Multimedia systems; Protection; Signal processing; Vehicles; Wireless application protocol;
fLanguage :
English
Journal_Title :
Networking, IEEE/ACM Transactions on
Publisher :
ieee
ISSN :
1063-6692
Type :
jour
DOI :
10.1109/90.851979
Filename :
851979
Link To Document :
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