Title: A model-based
scalable reliable multicast transport protocol for satellite networks
Authors: Prawit Chumchu,
Roksana Boreli, Aruna Seneviratne
Abstract: In this Paper, we design a new scalable reliable
multicast transport protocol for satellite networks (RMT). This paper is the
extensions of paper in [16]. The proposed reliable multicast transport protocol
does not require inspection and/or interception of packets at intermediate
nodes. The protocol would not require any modification of satellites, which
could be bent-pipe satellites or onboard processing satellites. We divide the
proposed protocol in 2 parts: error control part and congestion control part. In
error control part, we intend to solve feed back implosion and improve
scalability by using a hybrid of ARQ (Auto Repeat Request) and adaptive forward
error correction (AFEC). The AFEC algorithm adapts proactive redundancy levels
following the number of receivers and packet loss rate. This leads to the number
of transmissions and the number of feed back signals are virtually independent
of the number of receivers. Therefore, wireless link utilization used by
proposed protocol is virtually independent of number of multicast receivers. In
congestion control part, the proposed protocol employs a window-based congestion
control scheme, which is optimized for satellite networks. To be fair to other
traffics, the congestion control mimics congestion control in the well-known
Transmission Control Protocol (TCP) which relies on “packet conservation”
principle. To reduce feedback implosion, only a few receivers, ACKers, are
selected to report receiving status. In addition, in order to avoid
“drop-to-zero” problem, we use a simple wireless loss filter algorithm. This
loss filter algorithm significantly reduces the probability of the congestion
window size unnecessarily reduced because of wireless spatially uncorrelated
losses. Furthermore, to improve achievable throughput, we employ slow start
threshold adaptation based on estimated bandwidth. Our congestion control also
deals with variations in network conditions by dynamically electing ACKers