How MIT and Caltech's Coding Breakthrough Could Accelerate Mobile Network Speeds 129
colinneagle (2544914) writes "What if you could transmit data without link layer flow control bogging down throughput with retransmission requests, and also optimize the size of the transmission for network efficiency and application latency constraints? In a Network World post, blogger Steve Patterson breaks down a recent breakthrough in stateless transmission using Random Linear Network Coding, or RLNC, which led to a joint venture between researchers at MIT, Caltech, and the University of Aalborg in Denmark called Code On Technologies.
The RLNC-encoded transmission improved video quality because packet loss in the RLNC case did not require the retransmission of lost packets. The RLNC-encoded video was downloaded five times faster than the native video stream time, and the RLNC-encoded video streamed fast enough to be rendered without interruption.
In over-simplified terms, each RLNC encoded packet sent is encoded using the immediately earlier sequenced packet and randomly generated coefficients, using a linear algebra function. The combined packet length is no longer than either of the two packets from which it is composed. When a packet is lost, the missing packet can be mathematically derived from a later-sequenced packet that includes earlier-sequenced packets and the coefficients used to encode the packet."
The RLNC-encoded transmission improved video quality because packet loss in the RLNC case did not require the retransmission of lost packets. The RLNC-encoded video was downloaded five times faster than the native video stream time, and the RLNC-encoded video streamed fast enough to be rendered without interruption.
In over-simplified terms, each RLNC encoded packet sent is encoded using the immediately earlier sequenced packet and randomly generated coefficients, using a linear algebra function. The combined packet length is no longer than either of the two packets from which it is composed. When a packet is lost, the missing packet can be mathematically derived from a later-sequenced packet that includes earlier-sequenced packets and the coefficients used to encode the packet."
Nothing new under the sun, just new uses (Score:4, Insightful)
Sounds like Parchive from usenet, which is a really good idea in a lossy environment now that I think about it.
Re:Can we update the title please? (Score:4, Insightful)
Right. (Score:5, Insightful)
This is yet another form of forward error correction. The claim is that it doesn't take any extra data to add forward error correction. That seems doubful, since it would violate Shannon's coding theorem.
This was tested against 3% random packet loss. If you have statistically well behaved packet loss due to noise, FEC works great. If you have bursty packet loss due to congestion, not so great.