Sanjeev Mehrotra, Hua Chen, Sourabh Jain, Jin Li, Baochun Li, and Minghua Chen
Mobile broadband networks using 3G and 4G technologies
(such as EV-DO, HSPA, WiMAX, LTE) are rapidly
becoming one of the prominent means to access the Internet.
Multimedia consumption— requiring low delay, high bandwidth,
or a combination of both—is projected to become a large portion
of bandwidth utilization in mobile broadband networks. In this
paper, we study the fundamental problem of how packet loss
and delay vary as a function of the transmission rate over these
networks. With extensive real-world measurement studies, we
analyze the performance of a number of rate control algorithms
commonly used in media transmission. We show that the variable
nature of congestion signals (loss and delay) on these networks
leads to an ultimate failure of existing rate control strategies
to deliver adequate performance for multimedia applications.
In addition, we show how a rate control algorithm derived
from the utility maximization framework — which uses queuing
delay as the primary congestion signal — can be modified
to solve the challenging issues we have observed. By using a
variable threshold to define when the network is congested, our
proposed solution is able to achieve a significant improvement
over algorithms that use fixed definitions of congestion.
|Published in||IEEE GLOBECOM 2012|
|Publisher||IEEE Communications Society|