SATNAC 2009 Conference Papers
Protocols
Authors: Philip Foulkes (
Abstract: In the IT industry there is a trend towards
the convergence of the transportation of different types of content to single
networking technologies. Web, e-mail and VoIP applications all use a common
network to transport their data. This convergence leads to lower equipment
costs and allows for more future-proof networks to be built. Audio and video production environments tend
to use different technologies for the transportation of different types of
data. Different types of equipment use varying command and control protocols.
There are strict bandwidth, latency and timing requirements that need to be met
for transporting real-time audio and video data. IEEE 1394 is a standards-based networking
technology that meets these requirements. Ethernet AVB is an up and coming
standards-based networking technology that is designed to meet these
requirements. This paper discusses the initial phase of an investigation into
the interoperability of, and control over, IEEE 1394 and Ethernet AVB networks.
A tunnelling application has been developed that allows Ethernet devices to
take advantage of the capabilities of IEEE 1394. Control over the parameters of
the tunnelling software is performed by an IP based command and control
protocol, AESX170.
Title: Stimulating
Cooperation in Mobile Ad Hoc Networks
Authors: Johannes Göbel (
Abstract: Consider a mobile ad hoc network (MANET)
where packet transmissions occur between mobile nodes. Such a network requires
that the nodes act as relays to form multi-hop routes connecting the
origin-destination node pairs that are out of radio transmission range with
respect to each other. If the nodes do not to belong the same authority, then
the nodes must be given an incentive to spend their resources (battery power
and transmission bandwidth) in forwarding packets that originate at other
nodes. This can be done by introducing a credit balance for each node, where
the nodes use credits to pay for the costs of sending their own traffic, and
earn credits by forwarding traffic from other nodes. This paper presents
several variants of a credit-based incentive scheme (protocol) to promote
collaboration in MANETs. The variants address the fairness of the scheme,
namely (1) to assist those nodes that are under-provided with credits: such
nodes may lack the credits necessary to transmit their data, and (2) to protect
those nodes that are over-provided with credits: such nodes may, to their own
detriment, provide too large a proportion of their resources to the community.
We first present two basic incentive schemes: the first scheme does not
regulate the willingness of the nodes to forward packets on behalf of other
nodes; the second scheme contains such a regulatory mechanism. We next focus on
protocols whose design lies between the two basic schemes. Both the origin pays
and the receiver pays protocols are investigated. Both constant and
congestion-related resource prices are investigated. Initial simulation
experiments indicate that both the origin pays and the receiver pays protocol
with a credit distribution and discounting (redistribution) mechanism is
sufficient to afford a reasonably fair allocation of flows in the network.
Title: Understanding Channel Saturation in Multi-channel MAC
Systems
Authors: Mthulisi Velempini (
Abstract: Multi-channel MAC systems offer high capacity, a prerequisite for the
next generation networks. High capacity will ensure that the requirements of
delay sensitive and time bounded flows are met. For high capacity to be a
reality, a good channel selection, coordination and network connectivity is
required. A common control channel approach addresses the connectivity
challenge. However, it is perceived to be a bottleneck as it saturates
degrading data channels. The saturation problem is not widely studied. This
paper investigates saturation levels of both control and data channels. The
length and channel occupancy of control and data channels are explored. The
analytical results show that data channels saturates ahead of the control
channel. The model is premised on short control packets requiring shorter transmission
durations; meaning that a control channel is not capacity constrained as
compared to data channels.
Title: Error Correction with the Implicit Encoding
Capability of Random Network Coding
Authors: Suné von Solms (North West University),
Albert Helberg (North West University)
Abstract: We introduce a novel error correction scheme that uses the implicit
encoding capability of Random Network Coding. This scheme does not add
redundancy to the data prior to transmission, like existing error correcting
schemes. Random Network Coding within a large network generates enough
redundant information to perform error correction on transmitted data.