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Hardware

Mobile Satellite Internet Connections? 24

Posted by Cliff from the don't-try-this-at-60mph dept.
Anml4ixoye asks: "I am currently the webmaster for Hillsborough County, FL. Yesterday I had a meeting with the chief of Fire Rescue and they have a challenge. Our incident-command vehicle currently uses a cellular connection to the internet when a hard-line is not available (at the rate of 18c a min). They would like to switch to satellite internet, but need a way to automatically position the dish that is used. We're talking firefighter proof (as simple as possible). Any ideas on who to use, how to accomplish this, etc?"
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Mobile Satellite Internet Connections? More

Mobile Satellite Internet Connections?

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  • Heh, you could just drop an 802.11b card into the system and hope the incidents happen where a kindly company has a wireless network for you to access...

    Seriously, though, if you're talking about a mobile home-style command center, there are attachments to the directv dishes that make it pretty easy to aim them. I'd assume that holds for the DirecPC dishes too.
    Nevermind - I just remembered that the direcpc system needs a phone uplink, so that won't work.
    maybe just get a cheaper cellular connection? My Sprint one is much less than $0.17/min.
    • Both DirectTV and EchoStar (Dish network) offer 2-way sattelite now.

    • A guy I work with is in a similar dilemma -- lives in a massive RV, so any 'permanent' landline connection is out. However, I believe he checked into the Dish/DirectTV/etc.. options and evidently their setup is such that they only really permit permanent installation.

      I don't know if there's any real technical reason behind this besides the hassle of constantly realigning the dish.
  • How much bandwidth is needed? What kind of uses? If you're sending email, a Palm VII would do the job. If you want to watch a Stevenote [apple.com] your bandwidth needs will be higher.
    Many cell phones will act as a 14,400bps modem. DirecPC is supposed to be used with a 56k modem, but you could probably use it with the cell phone, if you don't mind diminished performance. There are automatic aiming systems for the DirecTV, but I haven't seen one for DirecPC.
    Good luck.
  • Is it just a cost issue or is is an availability issue? I think it would be pretty hard to beat $0.18/min with satellite. For a previous job, I took a long trip on a ship and our only internet connection was via Inmarsat (and analog modem)- which, if I remember correctly, was at least $1.00/min.

    If you want automatic positioning- check out the satellite antennas that they put on boats- they have 3 axes of gimbal so that they will continue to point at a satellite while the ship is moving at sea- your problem should be a bit easier, since you probably don't need the connection while moving.
  • Iridium offers data capability at 9600 baud via satellite phone with a serial interface. You dial up as normal using dial-up networking. I think they charge near $1/minute. Not too bad since taxpayers foot the bill anyways.

    I'd rather pay $1/minute then have my house burn down. The phones feature decent battery life, don't need to be aimed at all, could probably tie into a DC adapter into the vehicle.

    Also I believe Inmarsat and other satellite data providers have similar offerings. Hope this helps.

    Pat

  • Disclaimer: I have no personal experience with ham radio except to see a demo at my college many years ago.

    I've seen ham radio mentioned here a few times, and suspect it might be useful to look into what they have to offer. I have no idea of the geography of your area or how large the county is, but it might be possible to have a station at each fire station and link to that from the incident-command vehicle. Though the equipment would cost some money, there'd be no per-minute charge.

    An idea: check the phone book for ham equipment, and I'd expect after a few phone calls you could get some pointers to any local ham clubs in your area. Hard to beat hands-on experience. Good Luck!

  • Thaks for the answers so far. Just a little more info. Realize first that this is not used to transmit fire ground communications. The primary purpose of the vehicle is extended operations, such as New York, where we expect to be on the scene greater than two days. The Internet connection is used to get weather updates, haz-mat information, and communicate with Headquarters.

    Unfortunately, due to the size and wierd shape of our county, Ham radios would probably be out. And, because we have 900mhz radio communications, relatively unnecessary. And Satellite Internet is being advertised here for 39.95 per month, which would be a substantial cost savings to the taxpayers. (Yes, we actually care about you all).

    And maybe there isn't a system, but if anyone has creative ideas of how to build one, that would be appreciated as well. Thanks again!
    • You might want to hold off a little while

      I know SprintPCS and other cell vendors are rolling out high-speed wireless networks in Arizona and new mexico.

      I think the cost is alot more reasonable than normal cellular packet data too.

      Otherwise depending on LOS and other issues, you might want to consider using microwave trucks like the tv stations use. I know a town near me (Bethlehem, NY) uses a van with a microwave transmitter to relay to HQ when there is some sort of problem on the far side of town near the river.

      Best of luck.
    • Ham radios would probably be out. And, because we have 900mhz radio communications, relatively unnecessary.

      Well.. how fast do you need to go? You can run 56k or so on a 900mhz system. If you have any free channels on your comm system you could probably purchase radio data modems. The base then just needs an "always on" or dial on demand internet connection.

      Or if you don't want to pay excessive prices from your radio supplier you can buy a couple of 9600bps TNC's from a HAM radio outlet.

      Most of the inexpensive 2way satellite services require tricky aiming to get them working, probably beyond what your users are capable of. Automatic or aim free systems are expensive in equipment costs or services.

  • I have a friend who owns a satellite Television company. He installs Starband satellite internet systems sometimes. He has one of these on his RV. You just need to buy an aiming box (not sure what the technical name of these is) and re-lock you satellite everytime you move. Starband is two-way satellite internet. Its way faster than dial-up and is about $60 a month. BTW, these dishes can be cloned if you can use an E-Prom Burner.... so you can buy two sets from an irreputable dealer and use it @ the station when you are not out and about
  • I know it is taboo to say on /. but Microsoft(MSN) has a 2 way satellite system out. For this situation I am sure you could contact them directly, they may be interested in working out a solution for easy/automatic aiming with you to be able to offer it to other emergency departments.

    Worst case scenario is you buy one of their signal meters for aiming and spend 5 minutes with the trucks driver to teach him how to aim it in the general compass direction and then move it till the little arrow is as high as possible. Best case is MSN is able to devise a motorized system that auto tracks to the strongest signal. I'm no Electronics tech but I'm sure it can't be that hard to integrate a motor and small basic ROM to track the dish towards the strongest signal. Since time is not a factor it could spend 5 to 10 minutes to track the dish in every direction and then return to the strongest point, even faster if you integrate some logic to cut out obvious bad areas based on an electronic compass or relative signal strength in neighboring sectors.

  • Hillsborough is a tough area for wireless. CDPD would be fine in the built-up areas, but when you're out at a gasoline tanker spill in south county you're lucky to get a cell phone to work at all.

    I know others mentioned ham radio. It's just not a realistic option for what you need. Yes, I know all about APRS, but look at the APRS map for west central Florida. There's a big gaping hole where Hillsborough is, except for the NWS in Ruskin.

    Honestly, HCFR's best bet is probably to pack a standard consumer dish and other equipment. Pack spares of everything important. They won't have time to set it up right away, but if they're there for days, they'll have time.

    Another option could be to do data over their existing EDACS radio system (which is an 800MHz system, not a 900MHz). I know HCSO does data on the system, but I don't think anyone is doing IP or web browsing over it. Companies like Nettech sell systems to tunnel IP data over radio systems. Nettech calls theirs Smart IP. Their website also appears to be dead (http://www.nettechrf.com/ [nettechrf.com]) but their phone number is 609-734-0300. Here's a link [google.com] to an old press release about Smart IP.

    There are companies that sell systems that you're looking for (a self-contained, vehicle-mounted, auto-aligning satellite transceiver). NorcomNetworks sells a unit that is physically what you are looking for. It's a crock-pot sized unit that mounts on the truck. Inside, the dish automatically rotates and aligns with the satellite. Many utility companies use them. The problems are that I don't know if they provide a decent IP layer over that to browse the web and the cost can be a bit high. Their web site is down (http://www.norcomnetworks.com [norcomnetworks.com]) but their phone number is 703-262-0500.

    • Thanks for the ideas. Norcom Networks has changed their name (though I forget to what right now). They are great for small data transfer - such as realtime updating for delivery companies or field technicians. The drawbacks are that they charge by the Kb, and it's 2400/4800 baud up/down.

      Switching Cell providers may prove to be a bit of a challenge as well. The manufacturer of the vehicle specified CDMA phones, which is only used by Alltel/GTE/Verizon. AT&T (who a majority of our c-phones are through) does not have an interface for that.

      It looks more and more like this is going to have to go to our telecommunications section due to the abundance of options out there. Thanks!

      • It might be interesting for them to also push this up to the state level. I know there are about 4 comm trailers / go-packs available throughout Florida, maybe through the Division of Forestry, though I'm pretty sure that they are only voice. It might be worthwile to push the issue of adding some data/internet capability to them or as a separate set of go-packs.

        I would take a serious look at the idea of using Nettech's (or someone else's) stuff to do TCP/IP over the EDACS system. I know the radio shop guys (and probably Ericsson, Racom, or whoever is maintaining the system now) will resist it, especially given all the problems they've had with the system, but the impact on the system shouldn't be any different than the other data on the system. You take a normal EDACS data radio and the PC runs software that proxies/tunnels TCP/IP over the system. On the dispatch/server side, you just have another radio & PC to complete the other end of the tunnel. The expensive part is the software (I'm guessing $3k-5k for just the server and one client). Maybe it's worth somebody throwing that to the radio shop and having them determine if it's feasable.

        Actually, I've never seen the vehicle we're talking about. Maybe it's a new thing. Every big scene I've worked has been run out of the back of a Battalion Chief's SUV. Maybe each of those should have a laptop and with a cell phone dialup / CDPD connection.

    • "I know others mentioned ham radio. It's just not a realistic option for what you need. Yes, I know all about APRS, but look at the APRS map for west central Florida. There's a big gaping hole where Hillsborough is, except for the NWS in Ruskin."

      If the infrastructure isn't there, then work to build it. It's part of mitigation and preparedness for any future emergency situations.

  • I know sailboaters (see various races around the world) use satalite communication, and their conditionsare much harsher than what you need to deal with. They have equipment that can keep the dish pointed even in seas too rough to accually use the connection. I'm sure power boats have the same system though i've not heard of it.

    Sorry I don't know more details, but at least this is a direction to look.

  • I'm not sure where hillsborough fl. is but I'm sure there must be some huge R.V. dealers in fla., and any one of them can sell you disk aiming hardware and install it for you too. I believe these generally use G.P.S. to aim the dish, hold on let me see if I can google up a link. Hmm this looks interesting The satel-bag [rvsatellite.com], but you would probable need one of these Staellite finder [rvsatellite.com], but this isn't what I had in mind,ahhhere we go [motosat.com]. These guys have the equipment. From reading just now it seems that starband and direct tv 2 way dont work over a hundred miles from home but I sure there wust be some wway around this.

  • They two-way providers that have been mentioned unfortunately only work with fixed stations at the moment. The mobile automatic dish-pointing equipment is currently not up to the precision needed to point at the satellite. There are systems which work for satellite TV, however it is much easier to point a dish to receive than it is to transmit (to receive, you don't have to be that accurate, when sending from a dish however, you have to be pointed pretty much *exactly* at the satellite).


    -Jeff

    • In the army I worked on radar-doppler seeking guided missiles, and basicaly what we did was to place a rotating scanner in front of the feed (LNB in satalite talk). When the dish was pointed dead on, the signal came through clean, if it was off axis the scanner started to chop up the signal.
      Measuring the amount of chopping gave the magnitude of the error, measure the phase of the chopping gave the direction of the error. Feed these error back through some electronic and drive a few servos on the mount and your done.

      To use the system,
      1. you could program a box-search algorythm to automaticaly fine tune it after you got it close.
      2. You'd probably have to set the van up on sturdy jacks, someone walking arround on a vehicle supported by inflated tires, on sprung axles would surely through off alignment on a sat 22,400 mile away. (ground mount would help here also)
      3. Get the installer to align the thing on the satalite, so that its working correctly. (slip him a little cash on the side to get him to do it as exactly as possible :)
      4. align the scanner for zero error signal
      5. turn on the aiming system and see if it drifts off axis
      6. If it didn't drift off, manualy move it off axis and see if it returns
      As for the need for absolute presition, I don't buy it becuase
      1. the dish isn't that fast, as in telescope or photography fast, they look to be only about F 0.5- 0.7 in other word wide angled, and low gain
      2. The dish itself is rather small, the really directional stuff is about 10 wavelengths, these dishes only look about 3 or 4 wave lengths
      3. A modern amature telescope mount can with a little intervention hold on a star for several hours worth of exposure time
      4. the dish installer aren't all rocket scientists and they need to make a living too, so it realy can't be that hard
      5. the alignment technic is loosen the bolt turn the pipe, tighten the bolt and hope the thing doesn't jerk out of alignment a worm gear could change alignment increments from degrees to seconds of degrees!
      6. Even when its perfect today those birds do drift a little, they're not exactly over the equator all of the time! they must tend to pull towards the line connecting the center of mass of the sun and the Earth and the equator is only on this line durring the equenox's anyways.

      perhaps you can get an amature telescope manufacturer or amature astronomer excited with this idea in return for the potential sales, there must be a lot of fire-departments and other emergency services that need communtications such as Email or looking up an MSDS on a disaster site. My thaught is it may be impossible to do this on a mobile basis as in moving vehicle, but fairly easy to do on a mobile basis as a fixed location that occasionaly moves. Just have to start thinking outside the box here.

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