996XT GPS system lock/unlock performance

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soncorn

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I noticed that the 996XT seems to be quite a bit slower at responding to location changes and making the requisite Lock/Unlock of groups/sites.

How does the scanner process through these systems?

Is there anything short of having less things programmed in that will speed it up?

For example if a system is off by it's quick key will it then not be processed by the GPS "algorithm" until it is enabled?
 

clayman

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I've noticed the same thing. Having ranges being set down to the half mile doesn't mean much when it sometimes takes 2 minutes past the boundary to make the switch. I love the group level GPS, just wish it was a crisp and responsive as my 996T & 15T

Clayton
 

soncorn

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I've noticed the same thing. Having ranges being set down to the half mile doesn't mean much when it sometimes takes 2 minutes past the boundary to make the switch. I love the group level GPS, just wish it was a crisp and responsive as my 996T & 15T

Clayton
Precisely, if I was walking it wouldn't matter, but in a car you can pass most of the way through a "GPS circle" before the system unlocks, and then you are out of it for awhile before it locks back out.

Very disappointing.
 

bpsmicro

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Hmm, the revelation that Uniden broke one of the most important (to me) features is distressing. I was all set to upgrade one of my 996Ts with a 996XT, but I think I'll hold off a while and monitor this thread.

Most of my "circles" are 20 miles or more, so the problem may not be as pronounced for me, but it's a bit worrisome if something that worked really well now doesn't. :-(

On a related note, does anybody *really* use such small circles as 0.5 miles? I'd have preferred if they dropped off the bottom small circles (which to me, seem pretty useless) and made the bigger ones more granular (ie. 20, 25, 30, 35, etc).
 

K5RYA

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Hmm, the revelation that Uniden broke one of the most important (to me) features is distressing. I was all set to upgrade one of my 996Ts with a 996XT, but I think I'll hold off a while and monitor this thread.

Most of my "circles" are 20 miles or more, so the problem may not be as pronounced for me, but it's a bit worrisome if something that worked really well now doesn't. :-(

On a related note, does anybody *really* use such small circles as 0.5 miles? I'd have preferred if they dropped off the bottom small circles (which to me, seem pretty useless) and made the bigger ones more granular (ie. 20, 25, 30, 35, etc).
I agree, if the gps enable/disable is not working properly on groups on the XT then there is no point for me to upgrade.

As far as your questions on the smaller circles go, I think that is just because at this time you, like me, have a 996T and are only locking/unlocking sytems based on GPS, i know that when I get the XT and the ability to lock/unlock groups via GPS, I will use it to turn on and off say districts in a city. For instance, if you ever listen to all Houston PD channels at once, it is non stop, but maybe I want to hear just the district I am in, then that may be a fairly small circle for that group compared to the circle for the entire system. Even smaller circle in smaller towns.
 

UPMan

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I noticed that the 996XT seems to be quite a bit slower at responding to location changes and making the requisite Lock/Unlock of groups/sites.

How does the scanner process through these systems?

Is there anything short of having less things programmed in that will speed it up?

For example if a system is off by it's quick key will it then not be processed by the GPS "algorithm" until it is enabled?
soncom: Contact me by email at popitz@uniden.com. I'd like to try your setup to see the effect you are describing. I'm not noticing that for what I have programmed for the area.
 

bpsmicro

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I can definitely see 5-mile circles, but would something like a PD or Fire *really* have groups that only go out half a mile? I'm assuming that the Range field is bit-mapped, so has a specific number of "slots", which is why the granularity got lost at the higher end. Or, maybe it's just arbitrary. Of course, allowing me to punch in a number (eg. 23 miles) would be the ultimate. :)
 

Vern

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Just to be sure, check out your method of programming the radio...(software) to eliminate that as a source of the problem and not the radio.

I just got my 996XT programmed last weekend using ARCXT-PRO. I had to use a different version of ARC to copy FROM my old 996T, then import that ARC file into ARCXT, massage some of the data and then upload it to the 996XT.

I didn't notice the same problem that was described in the first post, but I have noticed that ARCXT may have some programming bugs. Many of my RANGE settings got changed. Further, even though all trunked systems were enabled to ID SCAN in the software when I went to use the radio after the programming I discovered that everything was on ID SEARCH. A possible bug report will be sent to Gommert @ Butel, but I cannot tell you if the problem was in the 996T download, the import by ARCXT, or what.

Once I edited those issues (via radio keypad) the 996XT's GPS function is just as good as the 996T.

I work in a county with 2,200 sq. miles and 35+ municipalities. I have 28 or so "systems" programmed into the radio. I love the way the radio interacts with the GPS to turn on/off systems as I roam about the county. I am primarily interested in what's happening in my vicinity and not so much in other places. The 996XT's ability to assign GPS to TRS sub-groups is pretty cool and was one of the features that I wanted.

73's
\/ern (still a very happy UNIDEN camper)
 

UPMan

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Long Answer:
The scanner assigns priority to scanning operations, and performs the location check task as a secondary function. If you have both a lot of (or large) systems/sites/groups and a large number of locations enabled for checking, there can be some lag...and the scanner is going to lag the location check over lagging scanning operation. This is a CPU resource tradeoff issue.

In the case I checked, there were systems enabled for 4 or 5 states (lots and lots of sites) all geotagged. Since it isn't likely you'd need to scan CO, TX, NM, OK all at once, or even all in one day (though I've personally made that trip in one day) disabling the SQKs for those far-off systems isn't unreasonable and will dramatically improve the location lock/unlock response. The scanner only checks unlocked systems whose SQK is enabled.

There is also some hysterisis built into the lock/unlock algorithm, to prevent "jittering" if you happen to be travelling right along the boundary of a geotagged element.

Short Answer:
No bug. Buy scanner. Disable distant stuff.
 

soncorn

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Any news on this?

Jim
I don't want to speak out of place, so I will limit my response re:Uniden to say that UPMan is looking into it as time allows within his busy schedule.


Now onto my observations.

Basically it is substantially slower on large numbers of active (quick key enabled) GPS "sites" (I use the term site, but I mean anything that has a GPS location that needs to be unlocked so this includes groups now).

I did a very brief test of the 996XT and 996T and found that the 996T had times of 14 seconds and 27 seconds to lock/unlock when entering or leaving a defined area. The 996XT had times of 20 seconds and 61 seconds.

The problem with this was that the 996XT only had about 100 GPS "sites" to process, the 996T had over 200.

I later did a one off test of the 996XT with probably 200+ sites to be processed and it took over 2 minutes to unlock a defined area.

I realize these tests are anecdotal, I don't have the time or the patience to engineer and then execute a test that is statistically significant. Suffice it to say that the 996XT is slower in locking/unlocking systems based on location
It is clearly slower. My main concern is for when I am traveling on the interstate or other highway on trips and have defined a town with a ~1 to 1.5 mile radius and that I am half-way through the town before it unlocks. Heck, if I have too many systems enabled (quick key on) I could be through some towns before anything even happens.

So the work-around is to spread systems out across quick keys and to keep to a minimum the number of GPS "sites" the 996XT has to process at any one time.

So where I used to keep the whole Colorado DTRS enabled using one quick key (that is 186 sites that I had in 8 systems) on the 996T I now have it divided across six (6) quick keys that I will enable/disable based on where I am traveling.

For my home area in the DFW metroplex I have done basically the same thing of dividing up systems more evenly across quick keys.

I am personally rather frustrated by this. The reason the 996XT was so great for me was that with the 25,000 channels (I had run out of space on the 996T's 6,000 channels) I was going to be able to keep it programmed with ALL my stuff for trips to various areas (Illinois, Missouri, all over Texas, New Mexico, Colorado, Oklahoma) without having to reprogram it do each trip like I would with the 996T.

I personally hope that the P25 performance is substantially better then 996T to make the 996XT worthwhile.
 
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Go slower or draw your circles bigger. I have the GPS on my BCT15 set for county lines and really don't have much problem with hearing the city cops, in the areas I travel that have small towns there is not enough radio traffic to be a bother so they come on with the county, not the city lines. When I get into areas that have more RF traffic, I have the circles a bit smaller, but still able to here what is going on a half a town away. I want to here whats going on before I hit city limits so I can prepare for or avoid something before I'm on top of it. If you look at the lon & lat as you drive you'll notice its not instantainious and at Interstate speeds it is quite a ways behind you. The OP even noted that his 996t could be 15-30 seconds behind and at 65-70mph a 1 mile circle doesn't mean much. Now at stop and go city driving(15-35mph) if you're in the next town before the system turns on, that would be a pain. And with it only being a circle, and I don't know of any cities or counties that are a circle, you're going to have some overlap somewhere, so I'd rather have them bigger and not miss anything.
 

clayman

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I appreciate Paul's explanation of CPU resources and GPS reaction time ( I suspected something like that. I had 168 systems in my 996T, with all but a dozen or so controlled by GPS (also had QK programmed just in case). With the 996XT, I still have 168 systems (so far), but nearly 400 groups/sites using GPS. The switch from system level to group level obviously increases the number of "GPS-enabled units" to keep track of. I think I'll assign some broad geographic areas to quick keys and disable the areas I'm not likely to be in regularly and see if that speed up the processing.

A couple of other notes. The 996XT will take any range in 1/2 mile increments up to 120 or 150 miles (don't remember off the top of my head), so if you want a range of 12.5 miles, it's no problem. This alone is almost worth the upgrade if you use GPS. I've cut down some unwanted overlap, and can now be more precise. The smallest range I am currently using is 1 mile, for some business sites I do or have done work at, although right now I generally pass them without them unlocking due to lag, Hopefully some judicious use of quick keys will help alleviate this.

Thanks Uniden and Paul for your continual improvements, hard work, and support

Clayton
 

K5RYA

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Just to comment, I got my 99XT in yesterday, and the responsiveness of the GPS location control seems great, very quick and locking unlocking systems.
 
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