MIT scientists have developed a congestion-control system for wireless networks that would help cut back lag times and maintain high quality in video streaming, video chat, mobile gaming, and other web services
To keep internet services running smoothly, congestion-control schemes infer details about a network’s bandwidth capacity and congestion based on suggestions from the network routers, which is encoded in knowledge packets.
Choosing a good sending rate can be a robust balancing act. Senders don’t need to be overly conservative: If a network’s capability always varies from 2 MB/sec to 500 KB/sec, the sender may always send visitors at the lowest rate. However, then a Netflix video, for instance, will be unnecessarily low-quality.
Alternatively, if the sender constantly maintains a high rate, even when network capability dips, it could overwhelm the network, creating a large queue of data packets waiting to be delivered.
Things get much more complicated in wireless networks, which have “time-varying hyperlinks,” with rapid, unpredictable capability shifts. Depending on varied elements, such as the variety of network users, cell tower locations, and even surrounding buildings, capacities can double or drop to zero inside fractions of a second.
In a paper at the USENIX Symposium on Networked Methods Design and Implementation, the researchers offered “Accel-Brake Management” (ABC), a simple scheme that realizes around 50% higher throughout, and about half the network delays, on time-varying links.