Efficient Time-Based Topology-Dependent Scheduling for Radio Packet Networks
Efficient Time-Based Topology-Dependent Scheduling for Radio Packet Networks
Files
Publication or External Link
Date
2002-08-01
Authors
Nadeem, Tamer
Agrawala, Ashok
Advisor
Citation
DRUM DOI
Abstract
In Radio Packet Network (RPN), unconstrained transmission may lead to
collision of two or more packets. Time Division Multiple Access (TDMA)
protocol is a common used protocol to schedule collision-free
transmission for such networks. TDMA transmission allows a number
of users to access a single radio channel without interference by
allocating unique time slots to each user. In TDMA network, time
is divided into frames and a frame consists of time slots. For
networks where each node is a neighbor for all the other nodes,
each node should assign a different time slot in TDMA frame to
transmit in it to have collision-free transmission. Typically,
those time slots are ended by \emph{guard times} for propagation
delays. Those guard times are fixed for all time slots regardless
the actual needed propagation delays.
In this paper, we propose a topology-dependent algorithm that
automatically schedules collision-free channel access and specify
the time instant when a node is to send a packet. We use
variable guard times, instead of the fixed ones, calculated using the actual needed propagation delays between sources and
destinations. We show that with such scheduling algorithm, a 90%
saving in the original guard times could be achieved that
increases the network utilization by about 10%.
Also UMIACS-TR-2002-57