5GHz UK channels missing

Discussion in 'Network Routers' started by Joe, Mar 17, 2015.

  1. Joe

    Joe Guest

    This is my first venture into 5GHz.

    I bought a cheap and cheerful USB adapter off ebay and it is zonking
    along giving me 62Mbs compared with 20Mbs on 2.4GHz. The router is a
    HomeHub5. So far so good.

    I'm a bit gutted to see that I apparently can't use any channel higher
    than 48 although the adapter can go to channel 128.

    I've tried adjusting the Country Code in the adapters driver but it
    seems that the limitations are with the router.

    Is there a router I can buy which will let me use the missing channels?
    It MUST work with BT Infinity.

    Thanks for any help.
    Joe, Mar 17, 2015
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  2. Joe

    David Guest

    If you read:


    it says

    "If I have read the document correctly (and it is quite a hefty tome to
    get to grips with), it looks like channels 36 to 48 are not subject to DFS
    in the UK, but all other channels are required to implement DFS
    safeguards. This was quite a surprise, as I had previously believed that
    channels 36 - 64 were not subject to DFS (as they are designated for
    indoor use), with all remaining (outdoor) channels being subject to DFS."

    DFS is Dynamic Frequency Selection - as described in


    I haven't worked out yet if consumer 5GHz WiFi using DFS is legal in the
    UK or not.

    Anyway, it looks as though you need a router which supports DFS if you
    want to go above channel 48. Note that manufacturers will have made some
    effort to ensure that their routers sold in Europe conform to European

    Google is your friend.

    By the way - why do you need/want all these extra channels?


    Dave R
    David, Mar 20, 2015
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  3. Joe

    David Guest



    "The reason the upper channels are not accessible is because this part of
    the 5GHz band contains radar systems. These channels are subject to DFS

    These DFS requirements are complex and costly to get regulatory
    certification from FCC/ETSI. Following are the typical requirements for
    access points (AP) operating on 5GHz DFS channel:

    Before starting operation on DFS channel, scan the channel for Radar
    devices for 1 minute. If radar is detected follow step 4 otherwise start
    operation of DFS channel.

    Must detect non-Wi-Fi Radar devices with pulse width as small as 5us

    When radar device are detected stop operation on the channel within 500

    For AP vendors, this also means informing wireless clients to move away
    from this channel.

    Do not become operational of this DFS channel for at least 30 minutes and
    after that go to step 1 before becoming operational again.

    Given the above complexity many small office-home office vendors as well
    as some enterprise AP vendors don’t allow operation on DFS channels in the
    5GHz band at all. Many client devices are also not certified for DFS band
    operation. Even when APs are certified and support DFS channels AP vendors
    often recommend operation exclusively on non-DFS channels given the
    uncertainty of DFS channels support at the client device level."

    So it seems that you are very unlikely to get legal (or any) WiFi
    equipment to use the full range of channels unless you buy expensive
    professional kit.


    Dave R
    David, Mar 20, 2015
  4. Joe

    Ted Guest

    I'm using a Home Hub 5 and after many hours (This is my first foray
    into routers) I found that the HH5 will connect to the higher channels
    but that there is a considerable wait (up to 30 minutes) while it does
    so. I haven't a clue why or if the delay is a fault or intentional yet.

    I do however get a system message from the HH5 stating that the wait
    will happen.

    Why do I want them? Why not?
    Ted, Mar 20, 2015
  5. Joe

    Ted Guest

    Thanks again. As I say my bog standard HH5 goes there with a £9.99
    dongle from ebay.
    Ted, Mar 20, 2015
  6. Joe

    David Guest

    From the references I posted it looks as though your HH5 supports DFS -
    the waiting for 30 minutes to confirm no local radar seems to be part of
    the specification.


    Dave R
    David, Mar 20, 2015
  7. Joe

    Ted Guest

    Yes that is exactly what I thought. Thanks for input

    The waiting time seems to drop with channel. I.e on channel 100 the
    wait is only a minute or so. The speed drops with channel though like a
    brick so there doesn't seem much point in playing up there.
    Ted, Mar 20, 2015
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