1. aeldes1's Avatar
    Okay, so I've heard enough of people complaining about the GPS on the Bold not working, only to get it to work later. This is not a random thing, but it is simply due to the technology.

    For your device to be able to locate you, it must receive a signal from at least 4 satellites. You need 1 for each dimension, the x y and z planes of the 3D grid. Then you need the 4th since the satellites are moving, so there is a time aspect.

    These satellites are obviously far out in the sky. For the BEST signal you should be standing outdoors, with no tall buildings. A roof over your head blocks this signal from reaching the antenna of your device. Tall buildings make the signals bounce off them, confusing your device, since it will receive the same signal a few times around.

    So what does this mean in practice?! Essentially the GPS on the Bold works in the same way as that of a dedicated Nav unit, with one important difference. The Bold is a phone first and foremost. Therefore, there is a smaller antenna, and at the same time different wireless systems in the phone are interfering with each other, increasing the signal to noise ratio of the already noisy GPS signal. SO in practice, it will take longer for your Bold to get a "fix" onto the satellites.

    This takes to another point. We have 3 types of fixes; cold, warm and hot. In simple terms, a cold fix is when you turn on the GPS after having moved a long distance from the last fix. A hot fix happens when the GPS has been idle for a short time. Why is this important?! Well, the first time you turn on your GPS, the device has NO clue where you are. Therefore, this will take a loong time. Providing optimal conditions for it should help. Go outside, away from tall buildings. Next time you try to use your GPS you will get a fix MUCH faster. In fact, I am sitting in my room, and I got a fix on my bold within 20 seconds. This is because the device knows where to start looking for me from the previous session.

    Also, about aGPS.. This is simply a software feature available to cell phones. The fix of the GPS hardware takes much less time if it has a rough estimate of where to start looking for you. With aGPS, the software provides a rough estimate of where you are, to assist your hardware to find you. This rough estimate is provided from cellphone tower information, and is transmitted to your device over the 3G or EDGE connection, and uses up very little data. This will make it possible for your device to find a fix indoors at times.


    So no, your GPS is not broken. Be patient the first time! It's finding a needle in a hay-stack!


    If it's still taking forever, try this: Turn off all wireless connections on your phone, and try the GPS application again. You may not have map information, but it should be able to find you. The reasoning behind this is that other wireless connections interfere with the weak GPS signal(since there are from the sky, versus a tower 1000 meters away)


    If you guys have any further questions about the technology in general, please ask away. Also feel free to challenge any portions of what I have just written. Btw, I have some RF Engineering experience.
    08-29-08 11:53 PM
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