Network Coding for Efficient Communication in Extreme Networks - Revision history

Cotto at 08:59, 20 October 2006

2006-10-20T08:59:26Z

← Older revision		Revision as of 08:59, 20 October 2006
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	the paper: [http://sar/teaching/_previous-years/2006-s%20Interplanetary%20Internet%20Seminar/papers/ae_Network%20Coding%20for%20Efficient%20Communication%20in%20Extreme%20Networks.pdf"Network Coding for Efficient Communication in Extreme Networks"]		the paper: [http://sar/teaching/_previous-years/2006-s%20Interplanetary%20Internet%20Seminar/papers/ae_Network%20Coding%20for%20Efficient%20Communication%20in%20Extreme%20Networks.pdf"Network Coding for Efficient Communication in Extreme Networks"]

	~~The ZebraNet Wildlife Tracker ("~~http://www.princeton.edu/~mrm/zebranet.html")		[http://www.princeton.edu/~mrm/zebranet.html"The ZebraNet Wildlife Tracker"]

Cotto at 08:57, 20 October 2006

2006-10-20T08:57:40Z

← Older revision		Revision as of 08:57, 20 October 2006
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	==references==		==references==

	~~Network Coding~~ paper ("http://sar/teaching/_previous-years/2006-s%20Interplanetary%20Internet%20Seminar/papers/ae_Network%20Coding%20for%20Efficient%20Communication%20in%20Extreme%20Networks.pdf")		the paper: [http://sar/teaching/_previous-years/2006-s%20Interplanetary%20Internet%20Seminar/papers/ae_Network%20Coding%20for%20Efficient%20Communication%20in%20Extreme%20Networks.pdf"Network Coding for Efficient Communication in Extreme Networks"]

	The ZebraNet Wildlife Tracker ("http://www.princeton.edu/~mrm/zebranet.html")		The ZebraNet Wildlife Tracker ("http://www.princeton.edu/~mrm/zebranet.html")

Cotto at 08:50, 20 October 2006

2006-10-20T08:50:40Z

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	==Transmission method==		==Transmission method==

			Simple flooding algorithms simply forward a packet several times to increase the
⚫	To ~~achive~~ a lower number of transmissions every node in the network keeps
			possibility that the packet will reach it's destination in a certain time interval or
			after a certain number of hops. Thus we have to trust to chance that we are forwarding
			the right packet to adequate nodes. Moreover the energy consumption of every single
			node might be important. Many packet transmissions cause a high energy use. Therefore
			a protocol that gets along with less transmissions reach the destination node is needed.

		⚫	To achieve a lower number of transmissions every node in the network keeps
	sending linear combinations of the packages it has received or it is going to send		sending linear combinations of the packages it has received or it is going to send
	itself. Every packet (linear combination!) ~~contains a so called encoding vector~~		itself instead of forwarding every single packet. Every packet (linear combination!)
	that ~~inticates~~ the source nodes of the packages ~~being forwarded. Every source node~~		contains a so called encoding vector that indicates the source nodes of the packages
	is associated with a proper unit vector which is the ~~initial encoding vector.~~		being forwarded. Every source node is associated with a proper unit vector which is the
			initial encoding vector. Consequently a linear combination of two packets is made of a
			tuple consisting of a linear combination of the encoding vectors and a linear combination
			of the information vectors (data).

	A new linear combination is called innovative if it increases the rank of the set of		A new linear combination is called innovative if it increases the rank of the set of
	received packets of a node. Thus a solvable linear equation system is generated by each		received packets of a node. Thus a solvable linear equation system is generated by each
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	==references==		==references==

			Network Coding paper ("http://sar/teaching/_previous-years/2006-s%20Interplanetary%20Internet%20Seminar/papers/ae_Network%20Coding%20for%20Efficient%20Communication%20in%20Extreme%20Networks.pdf")

	The ZebraNet Wildlife Tracker ("http://www.princeton.edu/~mrm/zebranet.html")		The ZebraNet Wildlife Tracker ("http://www.princeton.edu/~mrm/zebranet.html")

Cotto at 17:16, 19 October 2006

2006-10-19T17:16:01Z

← Older revision		Revision as of 17:16, 19 October 2006
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	To achive a lower number of transmissions every node in the network keeps		To achive a lower number of transmissions every node in the network keeps
	sending linear combinations of the packages it has received or it is going to send		sending linear combinations of the packages it has received or it is going to send
	itself. Every ~~packets~~ (linear combination!) contains a so called encoding vector		itself. Every packet (linear combination!) contains a so called encoding vector
	that inticates the source nodes of the packages being forwarded. Every source node		that inticates the source nodes of the packages being forwarded. Every source node
	is associated with a proper unit vector which is the initial encoding vector.		is associated with a proper unit vector which is the initial encoding vector.

Cotto at 17:12, 19 October 2006

2006-10-19T17:12:41Z

New page

==Introduction==

Network coding is an experimental protocol for delay tolerant networks.
It aims on optimizing the packet delivery ratio in sparse and very sparse
networks. Furthermore the network coding protocol (NCP) reduces the total
number of transmissions in comparison with simple flooding algorithms.

==Transmission method==

To achive a lower number of transmissions every node in the network keeps
sending linear combinations of the packages it has received or it is going to send
itself. Every packets (linear combination!) contains a so called encoding vector
that inticates the source nodes of the packages being forwarded. Every source node
is associated with a proper unit vector which is the initial encoding vector.
A new linear combination is called innovative if it increases the rank of the set of
received packets of a node. Thus a solvable linear equation system is generated by each
node. As soon as the rank of the set of received packets equals or exceeds the
number of unit vectors (linear combinations of unit vectors!) in the equation system,
the node can resolve the equation system an extract every single packet.

==Managing Packet Generations==

Of course we need to be aware of older and newer packets. Therefore a hash value over
each packet id and source id is generated. Depending on the result of this operation
the packet is added to the corresponding matrix. Depending on the generation age
the rank of each matrix is reduced stepwise by replacing the last two rows of the matrix
by a linear combination of these rows. Thus the probability that a packet that might be
generated from that matrix is innovative is not reduced.

==references==

The ZebraNet Wildlife Tracker ("http://www.princeton.edu/~mrm/zebranet.html")