Verizon GPS Woes

[whoispetty]

I just got my xv6800 and am very excited about the switch from my apache, and i went through all the steps i thought i needed to get gps working on the Verizon network.

Updated my PRL to 2.47, updated my radio to 3.42.5. Then i cooked a new rom.

I thought I was going to have GPS ready then and there, since I followed the FAQ. But of course I get no lock.

Could someone please help me out and point me in the right direction? I have no data plan.

ROM 3.08.666.1 (This is a new one cooked in the kitchen)
Radio 3.42.50

[drewcam888]

I bet you have pri version 2.03xxx. This MR1/MR2 pri blocks gps. DO the below link. Then unlock and reflash custom. You can not jump from MR1/MR2 to custom without going to old pregps rom first to remove block.

http://forum.ppcgeeks.com/showthread.php?t=21161

[BigRedGonzo]

First of all, make sure your phone has location set to "ON" not 911 only. Tap Start>Settings>Personal>Phone, select the Services tab, highlight the Location Setting item in the scroll box, tap Get Settings and make sure the setting is set to on.

Being that you don't have a data plan, you need to make sure aGPS is disabled. This is a registry setting in HKLM/Software/HTC/SUPL AGPS, but I'm not sure which options to set to make it an independent GPS with no assistance.

GPS relies on a Satellite Position Database to locate satellites. The database is stored and built on your phone. When you use agps, you actually download the database from the net that would be appropriate for the closest cell tower to your position. This speeds the lock process up considerably. When the assistance is disabled, your phone (or gps) has to build the database itself. Since the unit has no earthly idea where you are when you first use the gps (i.e., the positional database is empty,) the phone has to build one. In order to do this, the gps chip must search for all known satellites one at a time. After it finds the first one, it then must locate a second and then it can get a 2D lock and things speed up considerably from that point. I went through all of that to say, once you get the gps function running without agps, it can take a long (very long) time to establish the first fix. To give you a feeling of what you are looking at, I have a very expensive handheld unit. If I clear its database and restart the unit and just tell it that it is in North America, it takes the unit up to a half an hour to get a lock. Once this is done, the unit locks very quickly when restarted later. The longer between sessions the longer it takes to "find" itself. I also have a very, very cheap bluetooth gps unit. It has no way of the user giving it a "general" location before start-up. If it has been off for several weeks, it can take it up to 11 hours to find a fix. After that, if it is turned on every week or so, it will lock on in just a few minutes. Both of these units have to build a database of their own to keep track of satellites. My 6800 on the other hand uses agps and therefore downloads a database of satellites that is very accurate for a position that is very close to its position, so it gets a lock in just a few seconds.

Now back to the point, it could take your phone several hours to find an initial lock without agps. It is very important for a cold start with no established database to have a very clear view of the sky while attempting to lock. Once you establish a lock, I would recommend using the gps every day or so to keep the database as up to date as possible. Remember that without agps, you will never get the 5-10 second locks that you read about on here. If you use the gps in the moring and turn it off and then use it again, say that afternoon, you should be able to establish a fairly quick lock (maybe one to two minutes,) but I wouldn't expect any more out of the unit than that.

Sorry about the rambling, but I'm at work waiting for a very important phone call and am bored out of my skull. I have work to do that isn't in my office and if I miss the call, I'm screwed. So I sit here and wait.

Hope this helps a bit.

[Vacs]

Check the settings in para 1 of the above post. Use a program called HTC Quick GPS to get initial data to help your gps get going, it does the same thing as agps does. You will need to use your wifi to get on the internet when you run it (it needs an internet connection). Quick GPS had a patch made to it somewhere along the line so try to find the patched version. Even ater running quick GPS it may still take 15 - 20 mins. to lock the first time.

Also, I never made any change to my reg. to disable agps. It may be a good idea for you to do it but I didn't need to. Also, my PRI is 2.03_002 and my GPS works sooo.....idk

Best thing if it is not too late is to turn the phone back into vsw and get the same thing from Sprint, then the gps won't be disabled. Why go through all this bother just to get what you paid for?