Protection
and Restoration in Wireless Mesh Networks
(NSF
Grant CNS-1116209)
PI:
Eytan Modiano
This project will develop mechanism for reliable communications over
wireless mesh networks, which have recently emerged as a promising solution for
providing last-mile Internet access. These networks will be tightly coupled
with the wired Internet to provide Internet services to end-users. While users
of wired networks are accustomed to highly dependable network services,
wireless networks have to contend with interference, obstructions, jamming, and
mobility, and are notoriously unreliable. The focus on this project is on providing
reliable communications in this challenging environment. In particular, we will
adapt, and augment, some of the techniques that have been very successful for
providing reliability in wired networks to the wireless environment.
Due to the challenging wireless environment, restoration in wireless
networks has been limited to dynamic re-routing of failed paths, with little,
if any, protection guarantees. Implicit in wireless networks, is the idea that
should a route fail, a new route will be found that can serve as a backup.
However, this ÓreactiveÓ approach, while simple, cannot be depended upon to
provide a high-level of reliability. A major goal of our work, which
differentiates us from previous efforts in this field, is to develop
ÒproactiveÓ mechanisms for providing reliable communications in wireless
networks. An important aspect of
the proposed research is to design network
restoration mechanisms that are tightly integrated with the wireless
transmission medium, and take into account interference and the need for
scheduling.
These mechanisms will include protection along preplanned backup paths;
diversity routing along multiple paths; and spare capacity allocation for
providing reliability guarantees. Moreover, many of the diversity concepts,
that have been used to provide reliable communications at the physical layer,
will be explored at the network layer for route diversity. Methods that utilize
redundant transmissions and routing along multiple paths will be explored in
order to increase network reliability; and techniques from the field of robust
optimization will be used to design a novel backup network architecture that is
robust to multiple random failures. Our research goals include:
á Develop new metrics for reliability in wireless
networks that go beyond connectivity metrics and take into account throughput
requirements.
á Investigate the impact of interference and scheduling
on wireless protection and restoration.
á Develop protection mechanisms that reroute failed
traffic along preplanned backup paths.
á Develop reactive restoration mechanisms using
Òdiffusion routingÓ and redundant transmissions.
á Develop reliable network architectures using
techniques from the field of robust optimization.
Participants:
Prof.
Eytan Modiano, PI
Greg
Kuperman, Graduate student