I need your help in exploring my options for communications from our remote site. It is in the mountains (50km south of Revelstoke BC, Canada)
with no cell phone coverage and closest phone line across the lake (~5km) - but it's a long distance phone call anywhere from there. Two issues need to be resolved with this new solution:
1. Continous data availability DNP3 data... the utility requires us to provide them with exception reporting (if no exception occured every ~2 minutes we are to give them status)
2. The solution is to provide us with data/fax lines that will be used for dialup control and also as a phone connection.
Currently we are using one set of microwave radios that we communicate across the lake and have 6 phone lines from there (towers are in place). This system works pretty good but needs a backup (redunduncy) and would become too expensive if it were to be used on 24 X 7 basis (with long distance charges) for the DNP3 data.
The main focus is reliability.... the communication lines must be open (i.e. ready/ available) 99% of the time... with maximum outage of no longer than 15 minutes at a time.
I am open to any suggestions: radios, satelites, magic black boxes that do it all, teleportation... :) Any ideas? What do you use?
Have you looked into Radio Modems. You can use multiple radio modems as repeaters to extend the distance. Try talking to companies such as:
Are any of the Satellite Internet providers available in that area? The DirecWay Satellite service provides always on, high-spped, two-way Internet access. Some friends I have in rural areas use it for home Internet access. Run TridiaVNC or PC Anywhere on a machine at the remote site, set up the satellite, and you're good to go. Earthlink re-sells DirecWay in the States; not sure who to contact in Canada.
Sage Automation, Inc.
Think about wireless ethernet modems with commercially available tools to transmit voice and data over standard ethernet. I know these devices exist, but am not sure who manufactures them. Data-Linc is a good source to talk to about the wireless portion.
I would suggest that it is impractical to be using dial connections for continuous monitoring and control. You did not indicate whether this is a problem for more than one site, but if not, a solution is to set up a single radio channel using UHF/VHF licenced radios. Data Radio has good data oriented radios at 5 W which with a repeater could get you 100 mile range. Equipment needs to be half duplex tolerent. If multiple sites, you might consider transparent spread spectrum radios with repeater capabilities in each node. ( "http://www.nbtinc.com/SR900.htm":http://www.nbtinc.com/SR900.htm ) This is more limited in distance (10-15 mi) and line of site. If your
repeaters have "the high ground", you should be able to get some pretty good range. With multiple stations being monitored, closer stations can
act as repeaters for more distant ones: the more stations, the better "area" coverage. If you really want dial/voice service, I can refer you to some manufacturers of radio telephone links.
Satelite would also be cost prohibitive if you are reporting continuously.
This maybe a choice for remotely communicatting to this site
Just a thought in the spirit of brainstorming:
Step 1. Microwave link as you use now to get near phone lines.
Step 2. Talk to the phone company about getting a dry loop (sometimes called an alarm circuit) brought from your tower, to someplace that will
allow you an internet connection.
Step 3. short haul modems on both ends of the dry loop.
Step 4. connect the second short haul to an internet connection, probably using a PC to store and forward the data.
Step 5. Have the PC dial in, DSL, cable modem, whatever into the internet, and either write an app to send the data, or, even better, have it send email every 2 minutes. That would give you a time/date stamp on the message that could be used for auditing.
Disclaimer: Any one or several of these steps may not be possible, due to circumstances. Sorry.
BTW, Step 2 and 3 is a good way to do a roll-your-own DSL connection, if you can find a willing party at the other end. That is partly why the
phone company is reluctant to admit they have the extra loops run.