802.11g and max speed <3MB/s

Discussion in 'Tomato Firmware' started by lanmtl, Jun 14, 2010.

  1. lanmtl

    lanmtl Addicted to LI Member

    Hello,
    Just wondering, why is it that I am getting between 2.6 to 3 megabyte/sec with my Tomato router over a 54mbits connection? I know there are some overheads but that's a lot of overhead here.
    The computer is about 2 metres away from the AP, RSSI is -41 and it says speed is 54mbits.
     
  2. mstombs

    mstombs Network Guru Member

    You need to be careful with your units, but wireless G is half-duplex which means transmits and receives use the same data channel, only one at at time, and your numbers are to be expected.

    The maximum signalling rate of wireless-G is 54 Mbits/per second. A Byte is 8 bits but there can be a parity bit plus stop bit etc so one way max communication say 5MBytes per second.

    Add in the protocol overhead, headers/ trailers and replies you easily get below 3MBytes per second. Then think about wireless to wireless transfers, and interference and resends...

    Broadcom Afterburner/ Linksys Speedbooster used to claim 125Mbs, later changed to up to 30% improvement which was more measurable. See Toms networking guides for real-world throughput measures.

    The headline figure is only marketing, not a patch on old-fashioned 100Mbps full duplex wired Ethernet which has been able to transmit bidirectionally at up to 100Mbps for the past 10 years - should have been marketed as 250Mbps (2 * 125Mbit/s signalling rate)!

    I suspect the same hype will be true for Wireless N, and the 300Mbit/s adverts will barely overload 100Mbps wired Ethernet, nor tax the 1000Mbit/s wired ports such routers will come with.
     
  3. lanmtl

    lanmtl Addicted to LI Member

    Thanks very much for the clarification!
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice