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HowTo Fix Galaxy S GPS

November 24, 2010 | Author:

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Smartphone without a GPS is like a Car without a music player. However, some manufacturers really face the challenge to produce smartphones with great GPS hardware –  initially even Apple did it bad in iPhone 3G.

Over my years of usages with different phones,  I’ve figured out the accuracy varies from manufacturer to manufacturer. What I’ve concluded is that HTC does a great job at creating high-end hardware and software, but Samsung seems to be concentrating too much on other aspects of the device – like the screen.

One of the worst part is that Galaxy S has a poor GPS quality, and same applies to most of the Galaxy devices.

If you own a Samsung smartphone, take some time out and read about it in detail below:

Samsung Galaxy S features the Broadcom BCM4751 chipset, here goes the true facts about it:

1. Obviously The Samsung Galaxy S is not a single-purpose GPS device. There will be inevitable design compromises when trying to fit all the hardware into the phone and in particular the GPS antenna will inevitably be inferior to the one in a standalone GPS or GPS Dongle. Having seen the GPS antenna it is indeed tiny, and halfway down the side, and at the back. But it needs to fit with the constraints of the hardware and has what appears to be a very sensitive chipset attached to it. I cannot find a full technical spec for the chipset but include a link to a technical overview in the footnotes. The GPS antennna on the i9000 is at the back of the main body, 1/4 of the way down the body on the left-hand-side as you view the phone in portrait mode. Image Here

2. If my conjecture is correct then I believe that Samsung/Google have made some design compromises in their software setup of the GPS on the Galaxy S that compromise positional accuracy, these can be overcome.

3. The GPS on any Samsung Galaxy S is fundamentally broken in any models. I do believe that the factory configuration choices are poor and I do believe it is hampered by hardware designs and their interactions with everyday use environments. Obviously any phone may have a one-off manufacturing defect but I cannot account for those.

Verizon has this to say about the MS- modes, two of the three fundamental ways (MS-Based, MS-Assisted and Standalone) that you can gain location information:

What is MS-Assisted mode of operation?

In MS-Assisted mode, the network elements calculate the location of the device. This mode is suitable for one-shot fixes, wherein the location does not need to be updated frequently.

What is MS-Based mode of operation?

In MS-Based mode, the network provides the satellite information to the device, based on a rough estimate of where the device is located, and the device acquires the GPS signals from the satellites and calculates its location. After the initial fix, the device operates like an autonomous GPS receiver, until the satellite information must be refreshed, at which time the device goes back to the network to update the satellite information. MS-Based mode is appropriate for applications that require the device location to be updated rapidly, such as a navigation application.

The current advice seems to be to enable MS-Assisted as it appears to improve navigation performance. I believe that this is incorrect. When using MS Assisted positioning I see considerable wander occurring as the position is not GPS derived. The MS-Based settings send the GPS Almanac and ephemeris date to the device and save on initial lock times, particularly if the GPS has been unused for many weeks, however in terms of positioning once up-and-running MS-Based and Standalone should deliver identical results.

Many users are primarily using the GPS in their cars. Here the hardware design compromises come in, but there are also some properties of GPS signals which users should be aware of. Firstly, RF Interference (RFI) is unlikely to be a primary culprit. The problem with a Car is that it’s made of metal which rapidly attenuates the already very low power GPS signal. When dealing with GPS the Signal-to-noise (SNR) ratio is important. Satellites giving the best SNR are always overhead, rather the near the horizon where the signal is competing with any number of other nearby frequencies causing RFI/ general background noise. So in a car, particularly given the design compromises with the GPS antenna, you will be attenuating the overhead signal because of the roof and relying more then you should on the GPS satellites near the horizon with their lower SNR, multipath propagation etc. When driving in a town where there is no horizon you can see where the problems arise. When the SNR becomes too great the GPS can no longer compute the pseudo range from the signal and you loose the ability to use a satellite. You can see a maximum of 12 GPS satellites at any one time if you have a full sky view – if you take away the overhead ones you can see why the number of useful signals drops below the minimum (4) very quickly.

This is a problem not just for Samsung but also for Google, who tout the Google Maps nav as a killer feature in a whole group of phones which have designs compromised by requirements to squeeze a lot of functionality into a small form factor. Samsung may have done a worse job of GPS antenna positioning in the SGS then maybe HTC in the Desire but they were faced with a different set of design constraints.

Before I tell you how to fix the GPS settings for best performance, here are some Tips for in-car reception:

1. Place the phone as far forward in the windscreen as you can. Note that Satnav systems usually come with a short-arm windscreen mount for this very reason as it ensures a great view of the overhead sky, yet we insist on comparable performance from our design-compromised phones when we attach them to the air vents or mount them in cup holders.

2. If you really want flawless in-car nav invest in a cheap bluetooth dongle. You will benefit from more flexible positioning options giving a better sky view, a larger antenna giving a better signal gain (and more directionality if it is pointing up) and if you get a SirfIII unit an extremely capable GPS chipset utilised without design constraints . Note that SirfIII does not always include WAAS while the Galaxy BCM4751 does, however for the requirements of in car navigation WAAS is really overkill and the quality of the signal/number of satellites in view is the real issue. It is no surprise that users find a bluetooth GPS unit gives better accuracy then the built in GPS – the antenna is massive and has a completely clear view of the sky!

How to Fix the GPS

Keep “MS Assisted” active. This is what is responsible for all the drift. Standalone and MS-Based will give a pure GPS signal. MS Assisted tracks based on cell tower signals and gives worse results.

Rest of the settings have to be made via LbsTestMode:
LbsTestMode can be enabled with the following key combinations in the dialler:

Android 2.1 – *#*#1472365#*#*
Android 2.2 – *#*#3214789650#*#*

Application Settings:

1. Session Type: Tracking

A chipset feature which helps to boost SNR in poor RF environments)

2. Test Mode: S/W Test

3. Operation Mode: Standalone

The most important setting as this is the setting. Standalone or MS-Based. Not MS Assisted. I have had the best results with Standalone, cutting the whole Assisted-GPS segment out of the equation. That way I don’t have to worry about who’s databases are up to date, which base stations might inaccurate etc. The standalone mode is able to do everything you need at the cost of slightly increased start times if not used for some time.

4: Start Mode: Hot Start

This has nothing to do with re-downloading almanacs. It simply resets precise satellite timing data that must be extracted from the GPS signal to compute an accurate pseudo range. It’s good for about 4-6 hours. If you leave your GPS off for longer then the ‘ephemeris’ data will be re-downloaded anyway regardless of the Hot/Cold start settings. The GPS can’t be ‘more or less accurate’ with or without it, its simply a case that the ephemeris must be updated before you can get any position. You can sync the clock every time if you want, personally I’d choose ‘Hot Start’ and save a few minutes every time a GPS app is destroyed!

5: GPS Plus: On

The GPS Plus is the Wide Area Augmentation Service, extra satellites that transmit a deviation correction to correct minor positional inaccuracies within the space segment of GPSl. Not available globally (North America and Japan, maybe Europe and India by the time the phone is obsolete). Having it on will not cause problems if WAAS is unavailable in your region.

6: Dynamic Accuracy: On

This setting is used to filter data that is judged statistically to be in error based on deviation from the Circular Error Probability (CEP) calculated by the GPS system.

7: Accuracy: 30m

I believe that this is a cut-off for the overall GPS positional accuracy. If over this threshold the GPS will not report the position. I have yet to see a figure of more then 20 meters, so leave at 30. GPS precision is far more complicated then a simple inaccuracy based on distance)

8: GPS Logging: Off

SUPL/CP Settings:

This is a network layer operated by cellular operators. It delivers the AGPS data like timing corrections and the almanac to your phone as well as allowing a network operator to provide you with various location based services (and make more money from you). If you wanted to download the almanac from satellites it would take a minimum of 12.5 minutes and would need to be done every time you turned your GPS on if it had been off for weeks/months. The almanac has a long lifespan, so won’t age out in days, and the GPS receiver is still capable of downloading it from satellites if it can’t get it from the network, It also provides information to your mobile provider about where you are, regardless of your Google privacy settings so that they can provide you with location based services (so Google isn’t the only geolocation bogeyman!)

Again, I think there are lots of false leads here. The one thing that may be true is that the original SUPL provider on
handsets was providing inaccurate data. Recommended settings:

Server FQDN Type: Custom Config
Server: supl.google.com
Server Port: 7276
SUPL Secure Socket: OFF
AGPS Mode: SUPL

Google do map WiFi hotspots in large cities, which is enabled by the “Use Wireless Networks” option in the android Menu. This may allow you to locate yourself accurately in an urban area where GPS is unusable. However, it is unlikely to provide tracking information for runners, probably providing street-corner location to pedestrians. This option may also activate the SUPL feature discussed above.

And that’s all you need. Hope all that helps get it fixed.

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Comments

  • Bobby

    Haven’t tried these settings just yet, but I can say this combination is a first. I have virtually tried every other setting combination resulting in extreme hit or miss results. The descriptive breakdown is well appreciated and hopefully this leads to a positive fix. Finally, a series of instructions from someone that makes some logical sense!

  • Bobby

    Haven’t tried these settings just yet, but I can say this combination is a first. I have virtually tried every other setting combination resulting in extreme hit or miss results. The descriptive breakdown is well appreciated and hopefully this leads to a positive fix. Finally, a series of instructions from someone that makes some logical sense!

  • Bobby

    Haven’t tried these settings just yet, but I can say this combination is a first. I have virtually tried every other setting combination resulting in extreme hit or miss results. The descriptive breakdown is well appreciated and hopefully this leads to a positive fix. Finally, a series of instructions from someone that makes some logical sense!

  • Bobby

    Haven’t tried these settings just yet, but I can say this combination is a first. I have virtually tried every other setting combination resulting in extreme hit or miss results. The descriptive breakdown is well appreciated and hopefully this leads to a positive fix. Finally, a series of instructions from someone that makes some logical sense!

  • Matolit

    thanks you are the best !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  • Techno_saggu

    Gr8 man, nice in detail explaination :)

  • Gabriel Carneiro Lopes

    Sorry, I don’t speak english well, but I think you’re undestande me: 
    I was giving up to put my GPS to work.
    Now everything is working, thank you for the information.
    Sincerely, Gabriel

  • Amata Ludu

    Wonderful work!  Thank you for the opportunity to read and clear up many questions about GPS.

    To me GPS is the most important part of a smartphone!  Right now I am in dilemma of weather to chose from HTC Sensation or Samsung Galaxy S2, so if someone knows the answer of the following questions, it would be greatly appreciated:

    1.  Does HTC Sensation have and internal antenna ?
    2.  Does Samsung Galaxy S2 have and internal antenna?
    3.  What kind of GPS chip does HTC Sensation uses?  Is it SiRF Star III chipset?
    4.  What kind of GPS chip does Samsung Galaxy S2?  Is it SiRF Star III chipset?
    5.  Does Samsung Galaxy S2 solely rely on A-GPS support in order to acquire position?
    6.  I noticed that HTC HD2 locks on satellites very quick.  Is that because its internal GPS antenna is makes contact with the metal back plate of the phone making that phone’s backplate to act as a larger external antenna (or is just in my mind :)   )?

  • Marklouieadame

    I think I recommend HTC phones they have better GPS Locked, I am presently using SGS 1 and sad to say that the Iphone 4 of my GF’s GPS is way better than my SGS. I tried HTC Sensation and it really locked on GPS really fast I just don’t know if SGS 2 performs better though

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    I spent $500 US dollars to get my first Galaxy S phone. The phone was OK but the GPS didn’t work. Also, I didn’t have contract with AT&T but the phone was still locked by AT&T. I was very disappointment with Samsung and AT&T.

  • http://www.reallyeasycart.co.uk/ Ecommerce

    Android is really making name in the industry. Almost all people now want to have android.

  • Gest
  • Michael

    Hi all, this link here fixed my GPS problems on my Galaxy S 100%, I had problems with my phone seeing satellites but the signal was too weak to lock! Turns out it is a hardware issue and easily fixed! http://androidum.blogspot.co.nz/2011/04/best-gps-fix-for-samsung-gt-i9000.html?showComment=1333509148860#c2002436344965492641

  • http://www.gsmbooster.co.uk/ phone signal boosters

    To get better quality GPS service, you should improve your signal strength firstly. If you have faced weak signal problem so you should try mobile phone signal booster which will boost your mobile signals.

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