John Geddes wrote:
> On Apr 15, 11:46 am, The Natural Philosopher <t...@invalid.invalid>
> wrote:
>> John Geddes wrote:
>>> On Apr 15, 9:58 am, J B <j...@invalid.com> wrote:
>>>> On 15/04/2011 09:52, John Geddes wrote:
>>>>> I have a project that requires a low-rate data connection to rural
>>>>> buildings without phone lines - in areas where mobile coverage is
>>>>> patchy. Installing a phone line and then paying for broadband feels
>>>>> expensive for the amounts of data to be transmitted.
>>>>> The pilot building is sharing a neighbour's ADSL via a wifi link, but
>>>>> there is an obvious problem of not being able to access the router if
>>>>> there are problems while the neighbour goes away on holiday. Even if
>>>>> we tried to duplicate this with another neighbour, it's not
>>>>> unthinkable that you could find both away for the same week.
>>>>> Data rates are very low, and latency would be no issue - but a quick
>>>>> look at satellite operators suggested substantial monthly charges
>>>>> however low the amount of data.
>>>>> Has anyone come across a satellite operator who offers a low standing
>>>>> charge? Other ideas?
>>>> Dongle?
>>>> Where exactly are you? There is a company in NW Wales who were offering
>>>> a wireless system which sounded interesting
>>>> --
>>>> J B
>>> The pilot is in Derbyshire, where Zycomm do offer a radio-based
>>> broadband service, but even their slowest service is £20 a month which
>>> is still quite expensive given the tiny data quantities (Probably
>>> around 1Mb per month). And I am hoping to serve a range of sites where
>>> such services aren't available.
>> well, let's see.
>>
>> A PAYG landline phone is about 10 quid a month, and on top of that will
>> be an 0845 dial up broadband cost.
>>
>> 1 Mbyte at say 36kbps over a modem, say 4k bytes per second is only 250
>> seconds of call per month. Or 4 minutes and a bit. Say 5 minutes
>>
>> No sure what 0845 numbers cost, but maybe 6p a minute? so that's
>> another 30p
>>
>> So the dominant cost is getting the phone line in, in the first place,
>> and it's rental.
>>
>> That has to be compared with the capital cost and rental of satellite
>> (much greater)
>>
>> You will be pushed to be able to remote access anything not on a
>> 'permanently on' style connection either. it is possible to admin a
>> remote *nix system over an auto answer modem, but I doubt you would want to.
>>
>> It is not clear whether these sites are attended or not. or whether they
>> are physically local. Can you e.g. run your own wires between them?
>
> Buildings will be generally unmanned and will be dotted across the UK,
> so no scope for own wires to connect them. The premises equipment
> (which is pretty basic) sends/receives TCP/IP.
>
Ah, so its not computers as we may think of them..talking about embedded
systems devices like perhaps weather stations?
> The basic economics of the satellite business (no limit on how many
> customer accounts and limited Mb with a high cost of adding more
> capacity) would seem well suited to pitch for business from customers
> attracted to a low-monthly-cost + high-variable-cost tariff (as long
> as they were willing to bear the cost of installation without
> subsidy). But I've not found anyone offering this yet.
>
And why would they care anyway for such a niche market.
Having done this sort of stuff in the past, Id be temped to construct
the whole shebang round very very simple linux boxes with dial up modems
in them. Make those auto answer, and then poll them from central and
pull the data over with UUCP. Or use PPP over the modems and the TCP/IP
suite of tools.
If you have a TCP/IP smart 'box' that needs something else in between,
again use a linux box and a modem as that 'in between' You don't even
need an ISP at all.If the remotes are passive slaves, waiting for phone
calls, you just need a smart box somewhere to dial up, suck the data
off, and drop the link on a timed script.
> John
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