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Is the Epic's GPS better than the Moment's?

Discussion in 'Android Devices' started by ShiftNo, Jul 16, 2010.

  1. ShiftNo

    ShiftNo Well-Known Member
    Thread Starter

    Oct 3, 2009
    Belleville, IL
    I've used the Moment, Hero, and Evo, and I noticed that the Moment's GPS was much, much worse than the two HTC phones. Even after the 2.1 update, the Moment would take a while to get a GPS lock, whereas the other two phones would generally be very, very fast to get a lock.

    Anyway, I'm wondering how the Galaxy S phones (specifically, the Epic) will fare when it comes to the GPS.

    Does anybody have any thoughts one way or another as to if Samsung has improved/fixed whatever it was in the Moment that made the GPS less than stellar? I've used a few different Moments, and they all seemed to have that same problem.


  2. crow11ad

    crow11ad Well-Known Member

    Oct 22, 2009
    I am sure Samsung took all concerns and hopefully listened.;)
  3. ragnarokx

    ragnarokx Well-Known Member

    Jun 27, 2010
    Los Angeles
    Guess we'll have to wait until there are some more in-depth reviews to find out how good the GPS really is.
  4. tomw3141

    tomw3141 Member

    Jul 22, 2010
    Hi Tech Mgr
    Northeast US
    I also own a Moment and find the GPS very disappointing. There have been comments in various posts regarding the Galaxy S version of the EPIC phone. They are very negative about the GPS. Apparently there is a firmware "fix" that improves it. I will wait to see what the reviewers and owners say on this issue.
    GPS Problem - Samsung Galaxy S Forum
  5. Adrift

    Adrift Well-Known Member

    Nov 1, 2009
    Corpus Christi, TX
    Actually you have it backwards... the EPIC is a version of the Galaxy S phone.
  6. taylormah

    taylormah Well-Known Member

    Jul 21, 2010
    I guess the people over in vibrant and captivate forums can let us know of this right now from their perspective. These devices have been out a week now..
  7. wodin6

    wodin6 Well-Known Member

    Dec 18, 2009
  8. njbianco

    njbianco Well-Known Member

    Nov 5, 2009
    metro detroit
    I hope after owning the Evo that its better then the moment I realized how bad my old Moments GPS truly was. My Evo locks onto location within 2-3 seconds when my Moment wouldn't even lock onto my location 60% of the time(if not ever).
  9. Porcelain_Frog

    Porcelain_Frog New Member

    Jul 25, 2010
    So far it isn't looking good for the Galaxy S series. As @wodin6 stated there is a quick patch for the GPS issue on the Galaxy S series but it isn't really a fix. The quick fix enables tower assistance but that ins't the root cause of the problem. A GPS shouldn't need assistance from towers and should work from satelites alone. Also the compass isn't working on the galaxy s series either. The compass uses a magnetometer and isn't related to the other GPS issue. So actually the Galaxy S series has 2 issues and not just one. Good luck using Google Sky map or other cool apps with this one without a working compass. I don't know if it affects all Galaxy S series phones but the complaint numbers keep growing and growing so it is a lot given the short time it has been on the market. I'm now glad they released it to other service providers first for "beta testing" before I jumped in with both feet on this one. Perhaps Samsung will have had time to truly fix this issue before the official Epic release on Sprint? I may just have to keep holding my breath for an Evo when and if they are ever available again.:eek:
  10. Bitbang3r

    Bitbang3r Well-Known Member

    Apr 24, 2010
    GPS shouldn't DEPEND on network assistance to work, but having network assistance available will cut the time to get a fix by ~30 seconds or more. This is because two kinds of data are involved with GPS:

    1) Telemetry data -- these are the signals broadcast by the satellites that basically say, "This is GPS satellite #27. It's exactly 8:47:29am on July 27th right... NOW!" If the receiver hears "...NOW" at 8:47:29.029, it knows the signal took 29 milliseconds to reach it, and based on the speed of light can calculate how many miles the signal traveled to get there.

    2) Ephemera data -- these are signals broadcast by all of the satellites for 6 seconds every 30 seconds. This data tells the receiver, "Here's where all the satellites were at some point in time, and here's what their trajectories were".

    In order to get a GPS lock, the receiver needs both sets of data. If it doesn't have current ephemera data available, it has to wait until a satellite broadcasts it, and it receives it without errors. That's going to take a bare minimum of 6 seconds under the most ideal conditions possible, and could easily take several minutes if all of the signals are poor. The only advantage to getting the data from a satellite is the fact that it spares you from needing network access at that instant. If you have network access anyway, you're better off just grabbing a copy over the network.

    Also, the signal quality you need to download ephemera data is much higher than the signal quality you need to do a telemetry reading. So, if you can grab the ephemera data over the network, you're more likely to get a usable GPS reading indoors, and will almost certainly get one a lot faster.

    I'm guessing that Samsung phones originally didn't use the network for ephemera data because HTC probably has a patent on it, or licensed it from someone who does. If Samsung phones do it now, that's good, because it means Samsung GPS will work better than it used to.

    This is NOT "aGPS". With aGPS, you're using the phone to grab the telemetry data, but using the tower to do the actual calculations.

    In retrospect, aGPS is kind of a valuable service, even for phones that can do GPS entirely on their own. Why? GPS triangulation requires a LOT of floating point math, and floating point math requires a lot of battery power to do quickly. You CAN have a phone actively sniffing its location 24/7 so it can instantly respond to queries from apps, but you'll murder your battery within a matter of hours if you try. On the other hand, if aGPS is available, you can leave the GPS chipset powered up enough to sniff telemetry data, but save the power-consuming math and offload it to the tower.

    As a practical matter, the time it takes to upload a few dozen bytes to a server at the tower, let it crunch the numbers against the ephemera data it already has in light of the fact that it already knows your approximate location (since tower location is fixed, and you're using that tower), and return a dozen bytes representing latitude and longitude is longer than it would take to determine your location if the phone were actively tracking it, but faster than it would take to do the calculation "cold" (if the phone were collecting data, but not doing the math until absolutely necessary).

    Put another way, if Sprint charged 99c/month for "accelerated GPS" service, and you did stuff that needed to be location aware throughout the day without killing your battery, it would actually be a pretty valuable service worth getting. The problem is, the people setting the policies and pricing don't understand the underlying technical issues, and think their official navigation service offers enough value to someone to be worth several times that amount (it doesn't, because Google Maps can do the same thing for free). The line between "worthless" and "useful" is kind of blurry, and inhabits a big gray area whose exact details are largely determined by the cost of the service and the size of your battery.
  11. PoundSand

    PoundSand Well-Known Member

    Jun 1, 2010
    highly doubtful

    it is agps. agps can (and does) refer to using the assistance server to provide additional information (ephemeris data, time, coordinates of towers, etc (basically any info to help lock onto the signal) to the phone, not just using the assistance server to provide calculations.
    Assisted GPS - Wikipedia, the free encyclopedia

    like your information on agps. :rolleyes:

    i keeed, i keeeed.
  12. hotani

    hotani Well-Known Member

    Dec 21, 2009
    Broomfield, CO
    Looks like the answer to the OP's question is a resounding "No". As it stands now, the Galaxy S phones seem to have the same (crap) GPS performance as the moment.

    According to this recent thread, a fix should be pushed out soon to ATT users, but I'm certainly going to watch this issue closely before buying an Epic.
  13. aeiou

    aeiou Well-Known Member

    Jun 9, 2010
    I had the Instinct, so i know about the GPS problems that Samsungs have. SMH
  14. 5Strong

    5Strong Well-Known Member

    Dec 11, 2009


    May even consider goint with the EVO. Especially if they drop the EVO price after the Epic is released.:p

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