Summary: Scheduling Over a Time­Varying User­Dependent Channel
with Applications to High Speed Wireless Data
Matthew Andrews \Lambda Lisa Zhang \Lambda
Abstract
In a wireless network, a basestation transmits data to
mobiles at time­varying, mobile­dependent rates due to the
ever changing nature of the communication channels. In
this paper we consider a wireless system in which the chan­
nel conditions and data arrival processes are governed by
an adversary. We first consider a single server and a set of
users. At each time step t the server can only transmit data
to one user. If user i is chosen the transmission rate is r i (t).
We say that the system is (w; '')­admissible if in any window
of w time steps the adversary can schedule the users so that
the total data arriving to each user is at most 1 \Gamma '' times
the total service it receives.
Our objective is to design on­line scheduling algo­
rithms to ensure stability in an admissible system. We first
show, somewhat surprisingly, that the admissibility condi­
tion alone does not guarantee the existence of a stable on­

Source: Andrews, Matthew - Mathematics of Networks and Systems, Mathematical Sciences Research Center, Bell Laboratories

Collections: Mathematics; Computer Technologies and Information Sciences