Comparing built-in GPS with Holux M1000
 

Just bought a Holux M1000 for $40, and man, there is absolutely no comparison to the built-in crap in N810 that Nokia calls GPS.

The Holux ALWAYS gets a fix within 30-35 seconds (even in the basement of my two story house). The 30 second figure is for a cold fix. If the unit has been off for a only a few minutes, it gets a fix in 3-10 seconds.

My N810 just took 3 minutes and 10 seconds to obtain a fix in my living room close to a large window. Then I shut N810 off for 10 minutes and tried to obtain a fix again. It took over 3 minutes. It appears that N810 tries to do a cold fix most of the time. Why Nokia, why?

In addition, the Holux typically sees twice as many satellites, and the signal strength is significantly better.

The Holux cost $40. After subtracting the cost of the battery, marketing costs, distribution, etc, the cost of the MTK GPS chip cannot be more than $10. The Holux is also very power efficient as it lasts over 20 hours on a relatively small battery.

Why Nokia did not use this chip in N810 is beyond me. Instead they went for the crappy TI GPS 5300 chip, which is also in their N95 and E90 phones.

Regardless of the chip, it appears that there is a problem with the GPS software. There is really no reason not to do a warm fix after only 10 minutes. I will open a bug.

Re: Comparing built-in GPS with Holux M1000
 

My guess is that that is why; they have used it as their primary GPS chip, so why switch now? Maybe they are getting a better deal by buying larger quantities of chips.

Re: Comparing built-in GPS with Holux M1000
 

I have an M1200 on order, to replace my aging TomTom Mark I Sirf II GPS.

I was also one of those contributing to the (as it turned out) myth that the N810 contained a SiRF star III GPS chipset. Of course now there's nothing to find, but at that time I could swear it was actually printed on a Nokia specs page. Now all I can find is 'Built-in GPS receiver'. In any case I'm sorry to have contributed to the confusion.

Big mistake by Nokia to use that TI chipset. Really, for a built-in GPS the _only_ useful chipsets are either the SiRF star III or the MTK chipsets, because with the other old-style chipsets you really need to be able to put the GPS receiver in a place with good reception. With a built-in GPS you don't have that flexibility. You must therefore have one of those hyper-sensitive chipsets where optimum signal reception positioning isn't critical.

(My old TomTom Mark I SiRF star II is actually fine, because I can position it just where it's possible to receive the signal - e.g. in that specially-made spot in metal-containing windscreens made for toll gate transmitters and the like. Not possible with a built-in GPS. I'm getting a new BT GPS simply because the power-on button on my old one is poorly designed and it accidentally turns itself on when I carry it or travel with it, resulting in an empty battery on arrival.)

Re: Comparing built-in GPS with Holux M1000
 

I think I read somewhere that the TI chipset has exceptionally low power requirements.

What is the battery capacity of the Holux. Could give a clue as to what inpact a "powerful" chipset would have.

I also assume size has something to do with it. Needs to be compact to fit inside an N95/N810.

Zuber

Re: Comparing built-in GPS with Holux M1000
 

The M1000/M1200 Holux GPS chipsets (MTK something) are also low-power chipsets. The quite small M1200 with a MTK MT3318 chipset should last up to 23 hours according to specs (with the battery in the M1200. I don't know its capacity but the M1200 is only 67 × 23 × 16 mm so the battery is pretty small).

The Freedom keychain GPS'es are even smaller and must thus have a very small battery, apparently they last some 9-10 hours still. They use a SiRF star III chipset though. That MTK chipset in the M1200 is supposed to be one of the chipsets with the lowest power requirements. Don't know how it compares to the TI chipset, but as the TI one apparently is pretty bad for its main purpose (lock to GPS satellites) it doesn't really matter if its power consumption is low..

Re: Comparing built-in GPS with Holux M1000
 

I have a Holux M 1000 as well and love it. Amazingly fast time to first fix, excellent receive sensitivity, locks tons of sats and they stay locked even in very challenging conditions. The built in GPS of the N810 and N95 (which I also own) is an absolute joke. They are next to useless for any practical use.

Re: Comparing built-in GPS with Holux M1000
 

I have a Globaltop and it seems to work as well as the Holux (but at 5Hz!).

I'm not sure the times don't represent the lower sensitivity. Open any external GPS and you will find a 2cm x 2cm x 3-4mm strip antenna. Try removing that and see how fast it gets a fix. You can't put that into a tablet.

You could put the MTK chip in, but it would eat even more power (and mapping programs also tend to eat the battery), and it might perform worse without a good antenna.

There are GPS repeaters, and I wonder how fast the TI would get a fix if one of these were used.

I consider it a nice backup GPS, but if you are going to use it seriously, there are very inexpensive bluetooth devices (the GTop 5Hz base model is $50, and for $20 more you can get an ultrathin model - buygpsnow.com has them - and a HUD version).

Re: Comparing built-in GPS with Holux M1000
 

I think the answer for Nokia is to impliment A-GPS in the same way they have for the N95/E90. It "should" be straight forward for them.

It would require internet access, but since the N810 is designed to be used with access to the net (WiFi) or Bluetooth, that should not be a problem most of the time.

On the N95, people reported lock times dropping from 5 mins to sub 30 seconds. Which is what we want.

Where is the best place to go, to suggest implimentation of A-GPS to Nokia ?

I think, if enough people did request it, it would rise up the issues list quite quickly...

Zuber

Re: Comparing built-in GPS with Holux M1000
 

The biggest advantage of MTK-based receivers is that they can track 30+ satellites simultaneously. This is what's responsible for 30 second cold starts -- the unit doesn't need to know where in the world it is, as it can track all (or most) satellites simultaneously. The N810 chipset can only do 12 satellites. So it needs to try the first 12 satellites, then try another 12 if the first 12 don't result in a fix, etc.

As I mentioned before, it appears that N810 does cold starts more often than is necessary (e.g. after a 10 minute period of inactivity). Has anyone noticed that the satellite status page of the map program rarely knows what satellites should be visible before a fix is aquired? It's almost as if it ignores available ephemeris/almanac data. In contrast, my 4-year old Garmin can plot visible satellites even after it's been off for a couple of weeks.

Re: Comparing built-in GPS with Holux M1000
 

I must be missing something very obvious: which GSM-circuit is built into the N810?