Network Coding - Revision history

Cotto at 17:12, 19 October 2006

2006-10-19T17:12:06Z

← Older revision		Revision as of 17:12, 19 October 2006
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	==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")

	NetCod conference: http://www.netcod.org/indexold.htm		NetCod conference: http://www.netcod.org/indexold.htm

Cotto at 17:08, 19 October 2006

2006-10-19T17:08:29Z

← Older revision		Revision as of 17:08, 19 October 2006
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			==Introduction==
⚫	NetCod conference: http://www.netcod.org/indexold.htm

			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")

		⚫	NetCod conference: http://www.netcod.org/indexold.htm

	==Software==		==Software==

Zubow at 10:02, 9 November 2005

2005-11-09T10:02:21Z

← Older revision		Revision as of 10:02, 9 November 2005
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	=Software=		==Software==
	Similarity flooding [http://iv.slis.indiana.edu/sw/simflooding.html]		Similarity flooding [http://iv.slis.indiana.edu/sw/simflooding.html]

Zubow at 10:02, 9 November 2005

2005-11-09T10:02:10Z

← Older revision		Revision as of 10:02, 9 November 2005
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	NetCod conference: http://www.netcod.org/indexold.htm		NetCod conference: http://www.netcod.org/indexold.htm


			=Software=
			Similarity flooding [http://iv.slis.indiana.edu/sw/simflooding.html]

Zubow at 09:55, 9 November 2005

2005-11-09T09:55:02Z

New page

NetCod conference: http://www.netcod.org/indexold.htm