Sending a signal long distance without internet?

[mxracer17788]

Hi all,

I have various stress gauges mounted in a stationary unit and we are trying to design a monitoring system for these gauges. Is there a way to have these units send data over a couple hundred miles without the use of internet? My first thought was radio waves but we would need an awfully large antenna to receive the signal. The reason that I don't want to use internet is because we would have to charge a monthly monitoring fee to cover the network data plan, and this would make the product far too expensive. Plus, I can't think of an easy way to have these units tap into the owner's existing internet connection. Ideally what we want is to sell these units, and then be able to replace them if we receive an alarm signal from the unit after too much stress has been achieved. What I'm asking for may be impossible, but I'm just looking for suggestions on possibilities to solve this issue.

Thanks,
Jeff

 

[robertjo24]

Have you considered cellular modems to accomplish this communications. The inital cost of the unit is a little high, but the MRC isnt too high. The systems can be accessed and monitored remotely.

Wireless over a 100 miles would require a low frequency (i.e HF), and therefore a very slow data rate and higher power requireemnt.

 

[VEBill]

I can't think of an easy way to have these units tap into the owner's existing internet connection.

It would be crazy to install a point-to-point radio link if there's already existing Internet connections at each end.

If it's just for an alarm condition, then perhaps a telephone dialer (connected to an existing telephone line) is all that's required. These are used in bugler and fire alarms systems, and could be applied to any alarm condition.

 

[biff44]

I worked on a system once that used spread spectrum modulation to send a very low level signal up to a geosynchronous satellite. The signal arriving at the satellite was below the KTB thermal noise, so it just looked like background noise. The satellite bent pipe repeated the signal back to an earth station, where the spread spectrum signal was recovered. It was used to track position of a fleet of trucks. The satellite company, of course, charged a user fee, and they had a wide range of requirements to meet. But it worked well.

You could have the various sensors at one location talk to each other on and ISM band, and a central transmitter pointed at the sky report that location's information.

http://www.MaguffinMicrowave.com

Maguffin Microwave wireless design consulting

 

[IRstuff]

Depending on how much data is being sent, some sort of prepaid cellular plan might result in a relatively low monthly cost.

TTFN
faq731-376

 

[DRWeig]

Google this: M2M cellular modem

The companies providing this solution have agreements with the providers (ATT, Verizone, etc) to use sidebands that are reserved for this purpose. Rates are very inexpensive. Aither-M2M in Atlanta is a good resource.

Good on ya,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies