Center for Satellite and Hybrid Communication Networks
General Publications

Technical Reports

Thesis Papers


Authors Featured on this Page:

M.S. Corson

C. Zhu

Recent Technical Reports Authored or Co-Authored by Dr. Chenxi Zhu (Ph.D. 2001)

Papers resulting from CSHCN-related research are periodically added to the Institute for Systems Research Technical Report Database where they can be browsed by year or searched by author or keywords.


A New Protocol for Scheduling TDMA Transmissions in Mobile Ad Hoc Networks (CSHCN TR 2001-19) by Chenxi Zhu, M. Scott Corson

A new protocol for scheduling TDMA transmission in a mobile ad hoc network is developed. With this protocol, nodes reserve time slots for unicast, multicast or broadcast transmission. The protocol uses contention for nodes to reserve transmission time slots, its operation is distributed and concurrent; therefore it is independent of the network size and can be used in large or dynamic networks. Its performance is studied with simulation and compared with IEEE 802.11 protocol.

QoS Routing for Mobile Ad Hoc Networks (CSHCN TR 2001-18) by Chenxi Zhu, M. Scott Corson

A Quality-of-Service (QoS) routing protocol is developed for mobile ad hoc networks. It can establish QoS routes with reserved bandwidth in a network employing TDMA. An efficient algorithm for calculating the end-to-end bandwidth on a path is developed and used together with the route discovery mechanism of AODV to setup QoS routes. Simulations show that the QoS routing protocol can produce higher throughput and lower delay than its best-effort counterpart.

An Evolutionary-TDMA Scheduling Protocol (E-TDMA) for Mobile Ad Hoc Networks (CSHCN TR 2001-17) by Chenxi Zhu and M. Scott Corson

A new single channel, time division multiple access (TDMA) scheduling protocol, termed "Evolutionary-TDMA", is presented for mobile ad hoc networks. The protocol allows nodes in an ad hoc network to reserve conflict-free TDMA slots for transmission to their neighbors. Two topology-dependent schedules are generated and maintained by the protocol: a broadcast schedule suitable for network control traffic and a mixed schedule which combines unicast, multicast and broadcast transmissions for user data traffic. The schedules are frequently updated in an evolutionary manner to maintain conflict-free transmissions. The protocol executes across the entire network simultaneously in a fully-distributed and parallel fashion. Traffic prioritization and Quality of Service (QoS) can be supported. Simulations have shown that the performance of the E-TDMA protocol is close to that of centralized algorithms, while being insensitive to network size in terms of scheduling quality and scheduling overhead. It is a scalable protocol suitable for very large networks, and networks of varying size.

Bandwidth Calculation in a TDMA-based Ad Hoc Network (CSHCN TR 2000-17) by Chenxi Zhu, M. Scott Corson

Bandwidth calculation for Quality-of-Service (QoS) routing in an ad hoc network employing Time-Division-Multiple-Access (TDMA) is studied.

Certain constraints of TDMA transmission in a wireless network requires careful scheduling among the nodes in order to achieve conflict-free operations. These constraints also make the calculation of the end-to-end bandwidth along a path non-trivial. These calculations are essential for QoS routing which requires a certain amount of bandwidth available on a route.

We prove the problem of calculating the maximal end-to-end bandwidth along a given a path in a TDMA network is NP-complete, and develop an efficient bandwidth calculation scheme. We also show how the bandwidth calculation scheme can be used with the Ad-hoc On-demand Distance Vector protocol (AODV) to perform QoS routing.


Some papers in the Technical Report Database are available for viewing in Portable Document Format (PDF). To view and print PDF files, you must have Adobe Acrobat Reader installed on your computer. If you do not have Acrobat Reader, you can download it by visiting the Adobe web site.

Other papers are available in Postscript (PS) format. To view and print Postscript files, you must have Ghostscript/GSview. Alternately, you can use Adobe Acrobat Distiller to convert the PS file to a PDF.

CSHCN > Publications > Technical Reports
Copyright © 2002 Center for Satellite and Hybrid Communication Networks, Institute for Systems Research, A. James Clark School of Engineering, University of Maryland. All rights reserved.
University of Maryland