alan Wrote:
The Rannoch Moor mast is in the programme to be upgraded to DC-HSDPA (which can achieve 22mbit in Inverness and Fort William), but Three can't or wont say when! Need to get beyond the overseas call centres to someone in the know about what backhaul Three have, because it sure as hell isn't the same as the BT exchange!
Backhaul for mobile phone mast has traditionally been a microwave link back to another mobile phone mast which then forwards it up the chain till eventually you get to a mast that has a fibre connection. You will usually see white circular things on the masts. Random Google search, first page I picked that shows what I mean.
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www2.redbridge.gov.uk]
The vertical white things are the transmitters that actually communicate with the phones. The large white circular thing is the uplink. The uplink is actually a dish, it looks flat because there is a cover over the top to stop dirt getting into the feed horn.
This works for two reasons, firstly traditionally mobile phones did not carry much data, and secondly the masts tend to be in high spots to give good coverage so they have good line of sight. With 4G and even some of the busier 3G masts the microwave backhaul is insufficient and fibre is required. A carrier grade microwave link is only good for a couple of Gbps at best which is an order of magnitude below a single fibre link, and typically fibre is laid in a bundle with more than one pair.
Life is harder for telephone exchanges because they tend not to have dirty great masts out the top and thus don't have good line of sight. Besides which microwave links don't have good bandwidth so the majority of telephone exchanges are now backhauled with fibre which of course is as I said before good for anything from 10Mbps to 100Gbps over the same single mode fibre depending what optics you put either end.
I am not sure where the Kingshouse exchange actually is however the Openreach where and when site at least has it down as under evaluation which is an improvement over a couple of weeks ago.
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www.superfast-openreach.co.uk]
The nearest exchange which is definitely getting upgraded is Ballachulish, though I notice that it has a microwave dish on the outside on Google Streetview, though that is four and half years old.
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goo.gl]
That said one of the things that the superfast broadband have been trumpeting is how much fibre is going to be laid in the Highlands, and my guess is a significant proportion will be to get fibre backhaul to the exchanges.
My guess is that Kingshouse is currently backhauled over an E1 link which is why you apparently cannot get the full throughput of the ADSL link speed.
The issue with exchange only lines is really stupid because there is no technical reason why they cannot put the VDSL2 DSLAM in the exchange, other than they have not been "qualified" to do so!!!