Difference between revisions of "Private:Random"

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== Transport Protocol for Asymmetric Communication ==
 
== Transport Protocol for Asymmetric Communication ==
Communication channels with asymmetric uplink/downlink bandwidth are very common nowadays. Popular residential access technologies, such as Digital Subscriber Line (DSL), often divide available bandwidth in an asymmetric manner, where the downlink bandwidth is much higher than uplink bandwidth. Other systems may employ two separate communication channels as uplink and downlink, where the downlink channel has much higher bandwidth than the uplink one. For example, in rural area, systems may use satellites or TV-like broadcast for downstream and use analog modem for upstream traffic. While this asymmetry might be desirable in server-client based applications, it is less ideal for peer-to-peer based ones. This is because a ''client'' may exhaust it uplink bandwidth without utilizing its downlink bandwidth, which gets simply wasted.
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Communication channels with asymmetric uplink/downlink bandwidths are very common nowadays. Popular residential access technologies, such as Digital Subscriber Line (DSL), often divide available bandwidth in an asymmetric manner, where the downlink bandwidth is much higher. Other systems may employ two uni-directional communication channels, where the downlink channel has much higher bandwidth. For example, in rural area, network systems may employ satellites or TV-broadcasts for downlink traffic and use analog modem for uplink traffic. While this asymmetry is desirable in server-client applications, it is less ideal for peer-to-peer applications. This is because a ''client'' may exhaust it uplink bandwidth without utilizing its downlink bandwidth, which gets simply wasted.
  
One nature question is: Can we allocate the, otherwise idling, downlink bandwidth for uplink usage, so that the uplink bandwidth is increased? In 2001, from information theory aspect, Adler and Maggs [[media:AM01.pdf]] showed that using a properly-designed protocol, the downlink bandwidth can be used to accelerate upload speeds. Note that, they did not propose a real ''network'' protocol that can be used in the wild. Instead, their work (and several other extended works) strived to ''prove'' the feasibility of dynamically reallocating bandwidths. Also the upper bound of the potential upstream bandwidth improvement has also been studied. See [[media:Gagie06.pdf]] for a brief survey.
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One nature question is: Can we allocate the, otherwise idling, downlink bandwidth for uplink usage, so that the uplink bandwidth is increased? In 2001, from information theory aspect, Adler and Maggs [[media:AM01.pdf]] showed that using a properly-designed protocol, the downlink bandwidth can be used to accelerate the upload speed. Notice that, they did not propose an actual ''network'' protocol that can be used in the wild. Instead, they strived to ''prove'' the feasibility of dynamically reallocating bandwidths. Extended works in the literature have also reveal the upper bound of the potential improvement on upstream bandwidth. See [[media:Gagie06.pdf]] for a brief survey and references.
  
To our best knowledge, there has been no practical protocol in the literature, which supports dynamic bandwidth reallocation. Using such a protocol can increase the bandwidth utilization of the residential (last-mile) links. It can be even more useful in rural area, such as deserts, where uplink bandwidth is limited by the infrastructure and likely to be low. Hence, designing and implementing a transport protocol for asymmetric communication, ideally a TCP drop-in, has potential to benefit a large number of users all over the world.
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To our best knowledge, there has been no practical protocol in the literature, which supports dynamic bandwidth reallocation. Using such a protocol can increase the bandwidth utilization of the residential (last-mile) links. It is even more useful in rural area, such as deserts, where uplink bandwidth is limited by the infrastructure and likely to be low. Hence, designing and implementing a transport protocol for asymmetric communication, ideally a TCP drop-in, has potential to benefit a large number of users all over the world.

Revision as of 14:53, 7 March 2008

Transport Protocol for Asymmetric Communication

Communication channels with asymmetric uplink/downlink bandwidths are very common nowadays. Popular residential access technologies, such as Digital Subscriber Line (DSL), often divide available bandwidth in an asymmetric manner, where the downlink bandwidth is much higher. Other systems may employ two uni-directional communication channels, where the downlink channel has much higher bandwidth. For example, in rural area, network systems may employ satellites or TV-broadcasts for downlink traffic and use analog modem for uplink traffic. While this asymmetry is desirable in server-client applications, it is less ideal for peer-to-peer applications. This is because a client may exhaust it uplink bandwidth without utilizing its downlink bandwidth, which gets simply wasted.

One nature question is: Can we allocate the, otherwise idling, downlink bandwidth for uplink usage, so that the uplink bandwidth is increased? In 2001, from information theory aspect, Adler and Maggs media:AM01.pdf showed that using a properly-designed protocol, the downlink bandwidth can be used to accelerate the upload speed. Notice that, they did not propose an actual network protocol that can be used in the wild. Instead, they strived to prove the feasibility of dynamically reallocating bandwidths. Extended works in the literature have also reveal the upper bound of the potential improvement on upstream bandwidth. See media:Gagie06.pdf for a brief survey and references.

To our best knowledge, there has been no practical protocol in the literature, which supports dynamic bandwidth reallocation. Using such a protocol can increase the bandwidth utilization of the residential (last-mile) links. It is even more useful in rural area, such as deserts, where uplink bandwidth is limited by the infrastructure and likely to be low. Hence, designing and implementing a transport protocol for asymmetric communication, ideally a TCP drop-in, has potential to benefit a large number of users all over the world.