Mike wrote:
Nico Coesel wrote:
Hello Folks,
A future application would require the transmission of small amounts of
data from deployed units to several bases (civilian stuff), service
locations, and such. Very little data, maybe 1kB/day. Bi-directional
would be nice but not (yet) required. The challenge is that much of this
will be located in the boonies, mostly south-eastern US. Also Caribbean
and other countries but that might be a whole 'nother matter. Units will
be mounted outdoors, mains power is available. If we use cell networks
the units would not necessarily all need their own cell number if it's
possible to shave off some cost that way.
Since I don't live there, what is the network with the best coverage?
Anything else besides cell networks? Reaching even some remote areas
would be nice. Cost per month is paramount. Latencies are not so
important, if a message gets delayed by 15mins that's ok.
Some operators offer data only service at a reduced price especially
for such applications. You might want to look into that (call their
busines sales department).
We will. Alarm companies use that service. However, there are a lot of
carriers. Often they promise you a rose garden when it comes to coverage
and the online maps are rather coarse. So I was hoping there'd be
someone who was involved in something like this in the south-eastern
part of the country. I live in the western part and out here I'd
probably approach Sprint or one of their resellers because my cell is on
their network and coverage is great.
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
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I have all (well, most of) the cell site & cell tower locations and
spectrum/technical data in the southeast US.
Most of data is proprietary, so it cannot be shared.
I understand. Just wish they'd have more meaningful and detailed
coverage maps with signal level lines and such.
However, I can tell you Verizon and AT&T would likely be your best
bets overall (as far as raw number of sites, coverage and network
capacity), but I'm not sure what kinds of data / telemetry plans each
offers.
Thanks. I believe Verizon uses CDMA and AT&T uses GSM so modem costs
would go up if we must use both. My preference would be CDMA networks if
there's a choice.
The devices would be uniquely identified on their respective networks
(federal law), but they may be willing to bundle a plan depending on
revenue, etc..
I know AT&T does have (or used to have) a division that dealt
exclusively with machine-to-machine telemetry using the cellular
network, but that was back in the days of CDPD, which has since gone
the way of analog...
.
I wouldn't waste my time with customer service. You'll need to find
someone higher up in the food chain.
I'll try to get you the right contact at AT&T.
Yes, we will try that.
That said, depending on your intended purpose, I'm wondering if you
may find the FCC has spectrum allocated for your needs?
It may indeed be cheaper to use a public network (like cellular/PCS),
but without knowing the application & budget, it's hard to say.
We can't really have out own receivers and antenna towers. Otherwise it
would indeed be cheaper and in some areas more reliable.
Satellite is expensive -- moreso than cellular / PCS, but it does have
better coverage. And (as previously mentioned), usually requires
antenna alignment.
Yesterday I have written to Globalcom, the company Martin suggested. No
response yet which is a wee bit disconcerting, but we'll see.
As for costs, there the initial upfront (for the hardware /
terminals), and the ongoing monthly expense for airtime billing, etc..
Plus, you'll have to consider power (solar?) for those sites in the
"boonies".
I mention this only because (by experience) you can't always rely on
carribean mains power...
Oh, we've got our experience there, too
I assume you have also considered Hurricane impacts to those public
networks.
After most storms, large chunks of the cellular / PCS networks go
offline.
Usually, these are related to widespread power outages (after gensets
run out of fuel and batteries fail).
But usually 90% or better restored within a few days (Katrina, Ivan,
Andrew, Wilma & Charley being notable exceptions)
Expect worse performance from Batelco / other carribean carriers.
That would be ok. Mostly it doesn't matter if the data is transmitted
during or after the storm. Even in the clean-up phase the equipment
won't likely be used anyhow, people have other things to worry about then.
Also, in the Bahamas, last I heard the best you could expect was EDGE
technology on the larger islands.
The smaller islands. GSM - maybe, but likely little if any reliable
coverage.
And a lot of those GSM systems were voice only. No data.
Of course, you won't have that problem stateside.
Voice only could be done as well, using plain old audio modem
technology. Even 1200bd over a crackly link would be plenty fast here.
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
The newer seismic sensors I run into in the boonies are using Wild
Blue internet. About $50 a month, but not a rubber ducky service.
The phone companies in the past have been notoriously nasty (more than
they usually are) for data services. San Jose had set up their
sprinklers using a cellular service. The service changed, wasn't
compatible, and the phone company said "Hey, sorry about that."
If you could get the data rate down, pagers would be a path to
investigate. There is an amazing amount of digital crap on pagers
these days, especially two way paging. Alarms of all sorts. Stuff I
probably shouldn't mention but critical to the infrastructure.