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What happens to navigation if you lose signal?

Discussion in 'Android Devices' started by BY724, Jun 11, 2010.

  1. BY724

    BY724 Well-Known Member
    Thread Starter

    Searched for this and couldn't find an answer...it's possible I didn't search hard enough though.

    What happens if you're using google nav and you lose 3G signal. Does the whole thing stop? I mean, the GPS should still be working, so it should still know where you are.

    Does the phone cache the exact route when you're using the phone, so the GPS can take over if you lose signal. And in that case, shouldn't you just turn off your 3g after starting the route to save battery?

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  2. OfTheDamned

    OfTheDamned The Friendly Undead

    The way it was explained to me....

    Google Maps/Nav downloads the whole trip at the very beginning. Once you are driving down the road your GPS location triggers the prompts for the direction to be read aloud. Since the GPS isn't really network dependent and the trip is already cached then more or less, yes 3G isn't an issue. The only time it does become a problem is if you miss a turn. Then directions need to be updated and that does require 3G again. This is also why you can be on a call and the navigation will continue to work in the background and even continue to tell you where to turn.

    As far as turning off 3G while you are using Nav to save battery, why not just use a car charger?
    BY724 and R0llTide like this.
  3. hallstevenson

    hallstevenson Android Expert

    Unless the trip is really short, you'd damn well better have it plugged in !! :D It will drain the battery awfully quick.
  4. droidkevlar

    droidkevlar Android Expert

    I lost data on a trip I was taking and it stopped giving me directions. I actually missed a turn cuz of it. Never lost data every again with nav so I cannot confirm it was just a fluke or not
  5. OfTheDamned

    OfTheDamned The Friendly Undead

    Did you lose GPS too? The way I understand it, the route should be cached on your phone and the turns are simply Lat/Lon markers in the route. Beyond possibly the images shown on the display nothing should really be relying on the network.
  6. hallstevenson

    hallstevenson Android Expert

    Should be easy to test...
  7. Demache

    Demache Android Expert

    I took a bus trip to New York. It was a 1300 mile trip so I had plenty of time to try it out. What I gathered was, if you started Navigation (or Google Maps really) while internet was off, it would request a data connection and would refuse to show your current location. However, if you lost signal or fell back to 1X data while it was running, it would keep working. Well, 1X is ridiculously slow as it takes 15 seconds to load one square, but it should still work.
  8. pavirotten

    pavirotten Android Enthusiast

    I just drove to Pittsburgh, PA, the other day and had to go through the Fort Pitt Tunnel. Halfway through, I hear a little voice say "GPS signal lost." After coming out of the tunnel, I had to merge two lanes over and get off at an exit less than half a mile from the tunnel.

    Fortunately, I already had the exit number showing on the display before I lost the signal otherwise I would have missed the exit. Immeidately after taking the exit, GPS was restored.

    So to answer the question "What happens to navigation if you lose signal," the last direction displays until the signal is restored.
  9. nomarsgirl

    nomarsgirl Android Enthusiast

    Tunnels are different. Gps must have a view of the sky to work. If you lose data on the open highway, the gps still works.
  10. pavirotten

    pavirotten Android Enthusiast

    I know, but I was just relaying my first experience losing the GPS signal.
  11. nomarsgirl

    nomarsgirl Android Enthusiast

    You could have dedicated gps and it wouldn't work in a tunnel and would need some time too regain a lock after you come out. I'm on tunnels a lot. In their infinite wisdom, the state decided to put the main highway through boston underground.
  12. nomarsgirl

    nomarsgirl Android Enthusiast

    In case anyone was wondering, google nav doesn't work in Canada. Turned on data long enough to get directions but navigation gave an error message.
  13. Demache

    Demache Android Expert

    That's because no oil powered phones in Canada have Google Navigation. :D

    Joking aside, its probably one of the shortcomings of the beta.

    Sent from an HTC Eris
  14. BY724

    BY724 Well-Known Member
    Thread Starter

    Thanks for the info!

    As far as that question is concerned, it's just one of those things that I think about that I'm sure doesn't matter at all. It would be in a car charger anyway (the trip is a few hours long), but I feel like the phone would be using more energy if the 3G is on, and not that it'd effect the charge if it's 100% anyway, but that its better for the better to be using less power. Or something. If that makes no sense, here's a better way to phrase my thought process:

    The battery only has a certain number of charge/recharges on it. With the 3G on, it's using more battery, so it's being recharged more, thus wearing out the complete life of the battery faster, though it makes no difference in the cycle life.

    I've really only used these forums to talk about/ask about thinks I'm not too sure about. I've had the Eris since November, and I'm good with technology in general, but I've learned a TON about phones from these forums. I try to only post/ask when I'm really unsure of something or could use some advice...so if what I posted in the last paragraph isn't remotely true (even though it makes sense to me), please let me know.

  15. paulmmcneil

    paulmmcneil Newbie

    I have used the navigator on a drive through Utah and Wyoming through lots of areas without 3g coverage, and it worked just fine. I noticed that the satellite view stopped updating (of course), but the street view stayed accurate and the gps signal kept it updated and I got the directions I needed.

    Although, if you go off course without 3g, I'm pretty sure you won't get a recalculated route!
  16. hallstevenson

    hallstevenson Android Expert

    The topic of the thread is what happens when you lose the data or 3G signal, not the GPS signal.
  17. I would think the phone would be drawing power from the car charger, like my ipods do, rather than simply draining the battery and constantly refilling it.
  18. Demache

    Demache Android Expert

    That's what it should be doing. It just runs off the charger, and trickle charges the battery just enough to keep it full.

HTC Droid Eris Forum

The HTC Droid Eris release date was November 2009. Features and Specs include a 3.2" inch screen, 5MP camera, 288GB RAM, MSM7600 processor, and 1300mAh battery.

November 2009
Release Date

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