New WiFi Protocol Boosts Congested Wireless Network Throughput By 700% 130
MrSeb writes "Engineers at NC State University (NCSU) have discovered a way of boosting the throughput of busy WiFi networks by up to 700%. Perhaps most importantly, the breakthrough is purely software-based, meaning it could be rolled out to existing WiFi networks relatively easily — instantly improving the throughput and latency of the network. As wireless networking becomes ever more prevalent, you may have noticed that your home network is much faster than the WiFi network at the airport or a busy conference center. The primary reason for this is that a WiFi access point, along with every device connected to it, operates on the same wireless channel. This single-channel problem is also compounded by the fact that it isn't just one-way; the access point also needs to send data back to every connected device. To solve this problem, NC State University has devised a scheme called WiFox. In essence, WiFox is some software that runs on a WiFi access point (i.e. it's part of the firmware) and keeps track of the congestion level. If WiFox detects a backlog of data due to congestion, it kicks in and enables high-priority mode. In this mode, the access point gains complete control of the wireless network channel, allowing it to clear its backlog of data. Then, with the backlog clear, the network returns to normal. We don't have the exact details of the WiFox scheme/protocol (it's being presented at the ACM CoNEXT conference in December), but apparently it increased the throughput of a 45-device WiFi network by 700%, and reduced latency by 30-40%."
Catchy name for an old idea? (Score:5, Interesting)
Sounds like they're messing with 802.11 CSMA/CA min channel idle time and backoff on the AP to boost its transmit priority (and probably also force RTS/CTS handshaking when there's too many collisions between client transmits).
Neat idea, but not exactly new. Plenty APs optimized for WISP usage do this already.
Maybe the novel part is in dynamically determining congestion level or something...
Coded TCP ? (Score:4, Interesting)
Is this the same as last months "breakthrough" technology described in the MIT technology review.
http://www.technologyreview.com/news/429722/a-bandwidth-breakthrough [technologyreview.com]
That breakthrough uses special coded TCP secret technology only known to the select few who sign the NDA. The rest of us have know it since 1951 as Hamming Codes, or more recently Forward Error Correction.
Re:Implementation Speculation (Score:5, Interesting)
Before a wifi device can transmit a packet, it must wait for a period of silence where no carrier is detected. Any device can simply keep transmitting to hog up the channel indefinitely.
This is the same idea behind the 802.11e burst mode, where you transmit a number of packets in quick succession, then ask the intended recipient to give you a bitmask of all the successfully delivered frames. Without pausing long enough for any other devices to jump in.
Short description sounds a bit like DAMA (Score:5, Interesting)
http://en.wikipedia.org/wiki/Demand_Assigned_Multiple_Access [wikipedia.org]
The wikipedia description actually makes it sound a bit more complex than it actually it. In packet-radio DAMA simply meant that the central station polled each node regularly and asked it if it has queued requests. The only thing a client was allowed to send without asking back was the "I am a new client"-message.