Hop is a transport layer protocol designed for wireless mesh networks. Hop is 1)
fast, because it eliminates many sources of overhead as well as
noisy end-to-end rate control, 2) robust to partitions and
route changes because of hop-by-hop control as well as
in-network caching, and 3) simple, because it obviates complex
end-to-end rate control as well as complex interactions between the
transport and link layers.
Hop features:
Hop maximizes channel utilization by
minimizing control overhead.
Hop is robust to message losses,
contentions, and network partitions.
Hop co-exists with delay-sensitive
traffic without adversely impacting their
performance.
Hop leverages in-network storage to cache
data, thereby improving throughput and resilience to disconnections.
Following diagram shows major components in Hop.
Software
Hop has been written using C and C++. The up-to-date version Hop v0.1 can be downloaded here. Hop is distributed under the terms of the General Public License as here.
We modified Madwifi driver version 0.9.3.2 to (a) enable 802.11e QoS support under Ad-Hoc-Demo mode, (b) emulate message losses, and (c) change number of link-layer retransmissions. The modified driver can be downloaded here . The README_UMASS lists all the modifications.
Documentation and Support
The documentation related to the implementation can be found in the README along with the code. The design of Hop is described in a draft RFC All questions should be directed to mingli@cs.umass.edu
