Communications of the ACM
A Faster Wireless Web
Transfers of large amounts of data across the Internet to wireless devices suffer from a key problem: The Transmission Control Protocol (TCP) used to send and receive that data can be unnecessarily slow.
A company called Aspera has now announced an alternative protocol designed to accelerate wireless transfer speeds. Called fasp-AIR, it includes new proprietary approaches to addressing problems of data transfer that are unique to wireless communications. The original fasp protocol is already used to boost regular Internet transfers. It was used, for instance, to speed up the transfer of files from New Zealand to the U.S. during production of the movie Avatar.
The main problem with the TCP protocol, which was designed before wireless connections to the Internet were commonplace, is that it doesn't know the difference between packets of data that are lost because of network congestion and those that are lost because of a weak wireless signal. TCP automatically throttles the speed of data transfer when it sees dropped packets, so that congestion doesn't overwhelm the network. That's fine when packets are lost because of congestion, but when the problem is a weak signal, it causes an unnecessary drop in transfer speeds that can bring downloads and uploads to a crawl.
For some applications, like streaming video and Internet telephony, it's possible to use an alternative like the User Datagram Protocol (UDP), which doesn't bother to confirm that all data has arrived intact. The price of UDP's speed is dropped packets of data--a result familiar to anyone who has endured the degraded quality of a video stream or telephone conversation when at the limits of a wireless network's range.
Fasp-AIR achieves faster speeds than TCP but doesn't result in any dropped packets, making it suitable for transferring data that must arrive complete and intact.
From Technology Review
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