Wireless data links for telemetry, south-eastern US?

[Joerg]

[snip]
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.

Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one point
in time.

Yes, that would be great. If still in existence maybe he has a gut feeling
about the longevity of such service, from a business POV.

We can't be the only ones needing such service.

Have you looked into frequency bands that would cover the territory by
means of enough power, but need an FCC license? How hard is it to get an
FCC license for one of the service bands?

It's not hard. But we cannot erect a tower next to all the units

Without a tower it would require lots of receiving stations all over the
land. Remember, it's the units in the field which must transmit data.
So, ideally one would try to use a network where they already took care
of setting up lots of towers and pay a reasonable fee. $40/mo for a cell
plan per unit would not be a reasonable fee. The $5/mo that I pay for my
cell could fly but that's only through Virgin on the Sprint network
which seems to not be as prevalent there. It comes with texting so that
would work.

 

[Joerg]

[snip]
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.

Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one point
in time.

Yes, that would be great. If still in existence maybe he has a gut feeling
about the longevity of such service, from a business POV.

We can't be the only ones needing such service.
Have you looked into frequency bands that would cover the territory by
means of enough power, but need an FCC license? How hard is it to get an
FCC license for one of the service bands?

It's not hard. But we cannot erect a tower next to all the units

Without a tower it would require lots of receiving stations all over the
land. Remember, it's the units in the field which must transmit data.
So, ideally one would try to use a network where they already took care
of setting up lots of towers and pay a reasonable fee. $40/mo for a cell
plan per unit would not be a reasonable fee. The $5/mo that I pay for my
cell could fly but that's only through Virgin on the Sprint network
which seems to not be as prevalent there. It comes with texting so that
would work.

Aaron: May not exist anymore, but google on AQUIS.

Interesting, SE coverage is pretty good and they even cover a few
Caribbean islands:

http://www.aquiscommunications.com/services/2caribbean.html

Thanks. I'll have a chat with them. Two-way paging might be an option.

 

[Martin Riddle]

[email protected] wrote:
[snip]
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.

Thanks, pagers are certainly an idea. Although we'd have to send
while most pagers only receive. So it would need to be a
bi-directional pager service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one
point in time.

[snip]

Aaron: "Possibly, but phone messaging has taken over. Why would you
need it? ... There were two way devices that were used to send data
from devices such as vending machines. I am sure something is
(still)
out there that can do it."

Thanks for asking Aaron, Jim. We need it because the stuff is
installed outdoors and requires regular refills, service upon certain
incidences, and all this isn't predictable because it depends on
(widely varying) usage intervals.

Vending machines often use a link into the custodian's phone, meaning
you must install a little doohickey there and plug it in. Ideally we
want to avoid the need for the setup techs to have to enter a
building. Nobody there despite having said so, keys not available, big
Rottweiler inside, the usual reasons. Also, the more stuff has to be
installed the higher the chance of people in that building screwing it
up, for example "I just plugged in my vacuum and then forgot ..." or
"We went to cordless phones so I threw away all this old stuff .. oh
wait ... s..t!"

Jorge,

Take a look here if you haven't found this already....

<http://www.rabbit.com/products/M2M_App_Kit/ESC_promo.shtml>

www.airdesk.net may be able to provide service in your are of interest,
or at least recommend one ( as one would think )

Anyway M2M is what you want to do, that may refine your search.

Cheers

 

[VioletaPachydermata]

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.
Use another domain or send PM.- Hide quoted text -
- Show quoted text -
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

"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.

Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.

There is a GSM company that exists strictly for roaming. [Commnet.]
I've been in some real remote areas and found their towers.
http://www.commnetwireless.com/
Not everyone knows about these towers since their provider may not
have roaming agreements with them. There are tricks to sniff out these
towers, but they are cell phone dependent.

Their coverage maps for both CDMA and GSM look quite paltry though:

http://www.commnetwireless.com/cove...mnetwireless.com/coverageGeneral/GSMLarge.htm

Nothing to write home about in the south-east at all.

Google has a cellsite database. They bought a company to get it.
Unfortunately, the database is pretty poor when it comes to GSM.

Comnet wireless is for fill in. It is not meant to be a network per
se. It is an interesting business model. They put up towers in remote
areas where there is no service with the intent to get roaming fees
from say AT&T and T-Mobile. So the way to view their network is to
look at it in relation to AT&T and/or T-Mobile sites. In the desert
southwest, comnet towers are popping up with seemingly no clients.

That practice sounds almost as retarded as you are.

 

[Joerg]

Rich Grise wrote:
[snip]
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.

Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one point
in time.

Yes, that would be great. If still in existence maybe he has a gut feeling
about the longevity of such service, from a business POV.

We can't be the only ones needing such service.
Have you looked into frequency bands that would cover the territory by
means of enough power, but need an FCC license? How hard is it to get an
FCC license for one of the service bands?

It's not hard. But we cannot erect a tower next to all the units

Without a tower it would require lots of receiving stations all over the
land. Remember, it's the units in the field which must transmit data.
So, ideally one would try to use a network where they already took care
of setting up lots of towers and pay a reasonable fee. $40/mo for a cell
plan per unit would not be a reasonable fee. The $5/mo that I pay for my
cell could fly but that's only through Virgin on the Sprint network
which seems to not be as prevalent there. It comes with texting so that
would work.
Aaron: May not exist anymore, but google on AQUIS.

Interesting, SE coverage is pretty good and they even cover a few
Caribbean islands:

http://www.aquiscommunications.com/services/2caribbean.html

Thanks. I'll have a chat with them. Two-way paging might be an option.

Apparently used a lot in vending machines: "My till is full" or "I'm
out of Baby Ruth candy bars" ;-)

That's exactly the sort of communications we need. But without requiring
any infrastructure on the deployement side other than mains power. Even
if we'd be restricted to the 140 characters of a text message or less on
a pager that'll be fine.

Important is to obtain decently priced modems. Ideally I'd like not to
roll my own because of the time-consuming FCC certs.

 

[Joerg]

On Wed, 16 Sep 2009 09:40:27 -0700, Jim Thompson

[email protected] wrote:
[snip]
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.

Thanks, pagers are certainly an idea. Although we'd have to send
while most pagers only receive. So it would need to be a
bi-directional pager service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one
point in time.

[snip]
Aaron: "Possibly, but phone messaging has taken over. Why would you
need it? ... There were two way devices that were used to send data
from devices such as vending machines. I am sure something is
(still)
out there that can do it."

Thanks for asking Aaron, Jim. We need it because the stuff is
installed outdoors and requires regular refills, service upon certain
incidences, and all this isn't predictable because it depends on
(widely varying) usage intervals.

Vending machines often use a link into the custodian's phone, meaning
you must install a little doohickey there and plug it in. Ideally we
want to avoid the need for the setup techs to have to enter a
building. Nobody there despite having said so, keys not available, big
Rottweiler inside, the usual reasons. Also, the more stuff has to be
installed the higher the chance of people in that building screwing it
up, for example "I just plugged in my vacuum and then forgot ..." or
"We went to cordless phones so I threw away all this old stuff .. oh
wait ... s..t!"

Jorge,

Take a look here if you haven't found this already....

<http://www.rabbit.com/products/M2M_App_Kit/ESC_promo.shtml>

500 bucks? Yikes. Rabbit is close to where I live but has always been on
the pricey side which is why I never used them for actual product. I am
thinking along the lines of <$50 for each modem. For cell that number is
feasible, there I'd have solutions.

www.airdesk.net may be able to provide service in your are of interest,
or at least recommend one ( as one would think )

Anyway M2M is what you want to do, that may refine your search.

A repeater-style mote system would not work here. We may have one lone
machine out there in Podunkia and the next one 50 miles down the road,
way out of radio range.

 

[Joerg]

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.
Use another domain or send PM.- Hide quoted text -
- Show quoted text -
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.

Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.

There is a GSM company that exists strictly for roaming. [Commnet.]
I've been in some real remote areas and found their towers.
http://www.commnetwireless.com/
Not everyone knows about these towers since their provider may not
have roaming agreements with them. There are tricks to sniff out these
towers, but they are cell phone dependent.

Their coverage maps for both CDMA and GSM look quite paltry though:

http://www.commnetwireless.com/cove...mnetwireless.com/coverageGeneral/GSMLarge.htm

Nothing to write home about in the south-east at all.

Google has a cellsite database. They bought a company to get it.
Unfortunately, the database is pretty poor when it comes to GSM.

Comnet wireless is for fill in. It is not meant to be a network per
se. It is an interesting business model. They put up towers in remote
areas where there is no service with the intent to get roaming fees
from say AT&T and T-Mobile. So the way to view their network is to
look at it in relation to AT&T and/or T-Mobile sites. In the desert
southwest, comnet towers are popping up with seemingly no clients.

Thanks, I wrote that into the file, will look into it.

http://sourceforge.net/projects/signallocbb/

Hmm, that leads to BlackBerry routines:

http://f5bbutils.fairview5.com/

 

[Joerg]

Jim Thompson wrote:
Rich Grise wrote:
[snip]
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.

Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one point
in time.

Yes, that would be great. If still in existence maybe he has a gut feeling
about the longevity of such service, from a business POV.

We can't be the only ones needing such service.
Have you looked into frequency bands that would cover the territory by
means of enough power, but need an FCC license? How hard is it to get an
FCC license for one of the service bands?

It's not hard. But we cannot erect a tower next to all the units

Without a tower it would require lots of receiving stations all over the
land. Remember, it's the units in the field which must transmit data.
So, ideally one would try to use a network where they already took care
of setting up lots of towers and pay a reasonable fee. $40/mo for a cell
plan per unit would not be a reasonable fee. The $5/mo that I pay for my
cell could fly but that's only through Virgin on the Sprint network
which seems to not be as prevalent there. It comes with texting so that
would work.
Aaron: May not exist anymore, but google on AQUIS.

Interesting, SE coverage is pretty good and they even cover a few
Caribbean islands:

http://www.aquiscommunications.com/services/2caribbean.html

Thanks. I'll have a chat with them. Two-way paging might be an option.
Apparently used a lot in vending machines: "My till is full" or "I'm
out of Baby Ruth candy bars" ;-)

That's exactly the sort of communications we need. But without requiring
any infrastructure on the deployement side other than mains power. Even
if we'd be restricted to the 140 characters of a text message or less on
a pager that'll be fine.

Important is to obtain decently priced modems. Ideally I'd like not to
roll my own because of the time-consuming FCC certs.

No phone lines or cell phone towers around?

Phone lines would require to enter premises. And sometimes there is
none. Cell towers, that's why I started the thread, to see who is the
prevalent carrier down there. This is where Aquis looks rather promising
in their SE coverage.

Couldn't you use "calling card" pricing?

Usually not via cell or similar networks. Long distance typically makes
no difference, it's the air time and even more so the monthly fees that
count. And also modem costs if it's not CDMA or GSM.

 

[Joerg]

31:52 -0700, Joerg <[email protected]>
wrote:
[email protected] wrote:
[snip]
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.
Thanks, pagers are certainly an idea. Although we'd have to send while
most pagers only receive. So it would need to be a bi-directional pager
service.
Before there were cell phones I had a Motorola PageWriter which was
bi-directional. I don't know if anyone still offers such a service.
I'll ask my son... he was heavily involved in that industry at one
point in time.
[snip]
Aaron: "Possibly, but phone messaging has taken over. Why would you
need it? ... There were two way devices that were used to send data
from devices such as vending machines. I am sure something is (still)
out there that can do it."

Thanks for asking Aaron, Jim. We need it because the stuff is installed
outdoors and requires regular refills, service upon certain incidences,
and all this isn't predictable because it depends on (widely varying)
usage intervals.

Vending machines often use a link into the custodian's phone, meaning
you must install a little doohickey there and plug it in. Ideally we
want to avoid the need for the setup techs to have to enter a building.
Nobody there despite having said so, keys not available, big Rottweiler
inside, the usual reasons. Also, the more stuff has to be installed the
higher the chance of people in that building screwing it up, for example
"I just plugged in my vacuum and then forgot ..." or "We went to
cordless phones so I threw away all this old stuff .. oh wait ... s..t!"

As an aside, the infamous industrial vacuum cleaner is a classic
glitch source on the power line. ...

Tell the laser driver mfgs. A client had an expensive one running,
janitor comes in, plugs in one of them big silver Hoovers ... phut ...
*POOF*

... Having dealt with these gaming
companies, they routinely put glitches on their power inputs for test
purposes to insure noise spikes don't cause payouts. Things can get
out of sync between the display and the payout computer, and it gets
ugly. There is the occasional glitch that causes a slot machine to
physically display something that should pay out, but the computer
disagrees, and legally, the computer wins. ...

I would not want to be the one having to explain that to a group of
semi-drunk gamblers with tattoos all over ;-)

... Another EMI source is the piezo ignitor.

What do they ignite in there?

If there ever was a book to be written about glitching the mains, it
would be from these gaming/vending manufacturers, especially Mars
Electronics. Really sharp people there. Anyway, be sure to go nutso
over protecting your box in the field. Anything can happen to
something that is left unattended. Maybe a cyclic code in the data,
authenticity coding, stuff like that. Authencity coding is pretty
important if you use a pager scheme since there are (cough cough) test
programs to generate paging data, and of course surveillance software
as well.

Yep, been through the paces there. A lot. It gets really interesting
when stuff is directly exposed to thunderstorms like in this case.

 

[Joerg]

[email protected] wrote:

[...]

What do they ignite in there?

Yep, been through the paces there. A lot. It gets really interesting
when stuff is directly exposed to thunderstorms like in this case.

[...]


They use the piezo to ignite the gas (butance). When California
started the no smoking law in bars, I designed a box to detect the
piezo ignitor going off, mostly as a "can it be done" exercise, and
perhaps as something to patent. You can detect the lighter quite
easily. Just a bit of wire and a high impedance amp will sniff the
ignitor going off, so it was an hour of goofing off in the lab to put
it together. However, there are piezo ingitors in kitchen stoves,
which could be going off, and some really cheap lighters still use
flint.

Then they would have found out that by buying a cheap BIC lighter they
could get away with smoking

Actually the ones we use to light the kindling in the barbie are all
flint. Only the fancy long lighter for the wood stove is piezo. A friend
of ours has the best one: In the shape of a Winchester rifle.

I kid you not, I discovered a latch-up prone part when I switched off
a heat shrink gun and the spike when though the bench supply to the
DUT. This part already passed normal latch-up bench testing.

Whoops ...

As yet another aside, I put all my expensive electronics on a double
conversion UPS. I'm convinced the only way to trap power line surges
is to rectify the AC, filter and diode surge protect that DC,then use
a true sine inverter. Noisy and expensive, but worth it. There are non-
UPS versions of such gear sold to the high end video/audio market.

I must be lucky. Occasionally when I make a big mess while building
prototypes I haul the big shop vac in here and just fire it up. Nothing
has every reacted. Of course I am pretty diligent with line filters and
stuff.

 

[Joerg]

Switching the old Weller soldering iron on / off repeatedly was able to crash a PC.
Transformer...

Get a better PC

I have Wellers running here and I turn them off every time I leave for a
coffee on the deck etc. Never crashed anyhting.

 

[Joerg]

Well, that is why I started the thread. See if anyone knows about such
services that aren't likely to go away. I suppose I am not the only one.
There has got to be some stuff out in the boonies that's hooked up to an
alarm company. 20 miles beyond where the singing wires end or something.

Phut! *KABLAM* ;-)

Yeah, replace the fuse with a fuze

Isn't there a low frequency service that will meet his needs... create
your own radio link?

Remember, li'l box needs to transmit, no big antennae.

Hell! At his data rate... smoke signals ?

Would work. But frowned upon by some fire departments during summer.

 

[Paul Keinanen]

many government folks use meteor scatter, no kidding.

Remote meteorological stations have used these, but you need quite a
lot of effective radiated power. Since directional antennas could not
be used, quite a lot of transmitter power would be required.

Near Vertical Incident Skywave comes to mind as well and there are HF
utility band assignments for this sort of thing. Heck, NVIS messaging
would be a startup I would invest in.

A solar storm can severely disturb the ionosphere and hence take out
the communication for days.

Also thunderstorms can create quite high noise levels at the low-HF
frequencies.

In this case the antenna would have to be much smaller than the
wavelength and hence the antenna efficiency would be as low as 1 %,
requiring a considerable amount of transmitter (and hence main AC)
power.

Paul

 

[Joerg]

Look, there are older services in use out in the boonies, its just
finding them. I know there are allocations from my ham radio days.

That was the key word, "finding them"

There are 30, 49, 72,75 and 900 mhz distributed systems for this sort
of thing.

many government folks use meteor scatter, no kidding.

Are your units within a RF hop of each other or randomly distributed?

Nope.


If within a hop, you can use packet protocols, ie forward and store,
1200 or 9600 baud ham radio style packet works quite well on the
business band and there are HF packet protocols as well..

There were/are 138/142 Mhz low data rate satellite services , 220
mhz land mobile radio data services, and vehicle/cargo tracking.

Near Vertical Incident Skywave comes to mind as well and there are HF
utility band assignments for this sort of thing. Heck, NVIS messaging
would be a startup I would invest in.

Pipeline and Power companies need these services, and there are
pipeline and power companies everywhere in the US
Get a ride on some one else's low band or 900 mhz scada systems....

Hitching a ride is what I am after. Some sort of data packet shuttle
service.

Your looking in the wrong place with cellular.... There are FCC
allocations for this sort of telemetry. I would think inmarsat or a KU
band uplink is too expensive for you, but there are other services
for trucking, etc.

Try Orbcomm for example. There must be other little LEOs.

Thanks, added Orbcomm to my "must call them" list.

http://www.orbcomm.com/about/faq.htm

These things were around 700$ a few years ago: http://www.telcomwireless.com/globalcom.htm

And I would not doubt one bit that iridium offers a similar service.

Well, there is a cost cap on this. Sat is (usually) expensive but I'll
find out.

Take a look at the FCC regs, pick a candidate service and then go to
the FCC GIS and search for licensee within radius of a coordinate.

The radius would be thousands of miles and not all inside the US.

 

[Joerg]

[email protected] wrote:

[...]

I think satellite is a less stable platform than pager. The birds have
a limited life and get replaced often.

There are hospitals that depend on the one-way pagers since they
rather limit the transmitters on site for obvious reasons. Some places
take away your cellphone and give you a pager.

I think some form of paging will be around for a long time. The
problem is you don't know who the last man standing, OK, make that
company standing, will be.So you may have be to flexible in the pager
interface. Without going into details, it is pretty easy to figure out
which pager service has the most data customers. There are all sorts
of devices sending out their status over pagers.

This is what makes cell so attractive. The installed base is very large
so that a change in frequencies or protocol will be very slow or will
not happen at all.

 

[Joerg]

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.

[Forwarded from a Steve Roberts E-mail]:

Jim,

I can only post from google groups, tack this into the discussion for
me, would you?

Steve Roberts.

I posted this, but I doubt I get past his spam traps.

Quoting myself:

Thanks, Jim, and Steve. For some reason Steve's post did come through,
probably because it had a university *.edu address. Very puzzling, but nice.

 

[JosephKK]

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.

At a first cut you might wish to consider General Packet Radio Service
(GPRS) modems. The operating cost is based on data volume rather than
pure monthly. Otherwise, you may wish to look at what can be done
with ISM bands.

 

[JosephKK]

But doesn't that require a directional antenna? That wouldn't be
feasible in this scenario. Probably very expensive as well. Most of it
is just broadband like this:

http://business.hughesnet.com/


Regular cell for urban. AT&T is the best


Thanks. So AT&T is the best bet down there? In this area that's not so
hot after they went GSM. A neighbor had to put a yagi antenna onto a
plastic pole so his cell phone wouldn't quit in the house. Now he has a
tethered cell phone ... until the plan runs out.



Roaming charges are unacceptable and could be negotiated away. After
all, I don't pay any on my own cell. It's always 18c/minute no matter
what or where.

That is an expensive phone, unless all the minutes rollover forever.

 

[Joerg]

Martin Riddle wrote:

[...]

Roaming charges are unacceptable and could be negotiated away. After
all, I don't pay any on my own cell. It's always 18c/minute no matter
what or where.

That is an expensive phone, unless all the minutes rollover forever.

They do roll over. By now I have a bazillion minutes. I don't think
there is any cheaper way to have a cell phone and always keep the same
cell number. All those other deals I looked at required prepaid cards
that would expire in rather short time frames, between one and three months.

I pay around five bucks a month. That's it.

 

[Joerg]

At a first cut you might wish to consider General Packet Radio Service
(GPRS) modems. The operating cost is based on data volume rather than
pure monthly. ...

Do you know who the carrier would be in the SE?

... Otherwise, you may wish to look at what can be done with ISM bands.

That would mean our own RF links. It's what we are doing right now and
it requires a link through local premises. However, the goal is to have
the units send their data straight to a headquarters or a service location.