I like it, good technical explanation

How might we find out more? Perhaps someone from Nokia would comment in reply to the bug?

Yes, I moved along an East-West street. There was a big gap to the North. And I moved to have a small gap to the South. I don't know if the data retrieved earlier (when I was facing the big gap to the North) could help.

Yes, I supposed that this was the reason.

I thought that stale almanac (/var/lib/gps/nvd_data) was worse than none at all, but now I'm not so sure. I set up my tablet in my front yard with a view of about half the sky, and repeatedly started and stopped the GPS, and then again
but deleting nvd_data. With the file present, I get a fix[*] in about 18 seconds. Without it, it takes between 1-10 minutes.
Often it finds satellites in about 12 seconds but takes much longer
to get a fix.
I also experimented with deliberately setting the internal clock wrong.
If the clock is changed between fixes, TTFF is worse. But subsequent
fixes are OK. So having the clock systematically wrong seems to be
harmless.
http://andrew.triumf.ca/andrew/ttff.gif- normal
http://andrew.triumf.ca/andrew/ttff2.gif - w/almanac deleted


My Garmin has a "battery saver" mode; AFAIK it wakes up periodically to
take a fix, then goes back to sleep. It might be advantageous to do something similar in the N810, so that the almanac is always roughly correct.

Nice to know that Nokia is addressing this issue.

[*] With my test program, not a full-blown mapper -
http://andrew.triumf.ca/N810/demo4
http://andrew.triumf.ca/N810/demo4.c
modified from the Maemo application example
(needs to be run as root; use "./demo4 -s" to get output on the screen)

More from the trenches..

If you stop gpsdriver, then restart in the foreground, you can see its messages when the chip is turned on/off
# /etc/init.d/gpsdriver stop
# gpsdriver
gpsdriver is normally started on boot; it creates /dev/pgps and talks to the chip on /dev/ttyS0. It seems to read a binary format from the chip and write NMEA to /dev/pgps.
It saves the almanac in nvd_data.
Nokia Map (navicore) starts navicore-gpsd-helper and gpsd. navicore-gpsd-helper
tells gpsdriver to power up the chip. It also writes gps_last_saved_report when it quits.
gpsd reads NMEA from /dev/pgps and listens on localhost:2947
gpsd runs for as long as there are any clients, then it stops.
navicore and maemo-mapper (and generally any location consumer) read data from
localhost:2947. maemo-mapper 2.4.1 does not start gpsd itself.
My program demo4 both starts and stops the GPS chip via calls to gpsbt_stop(),
gpsbt_start(). navicore-gpsd-helper starts the chip, but does not stop it. If there are
no clients it will time out (30 seconds at least) and turn off, but I believe if there is a client (i.e. gpsd) it will stay on. If the chip is still on a client will get a fix quite rapidly.

This all seems needlessly complicated - four different programs running instead of the
mapper just reading the chip. But the chip format is closed and only one client can
connect to a serial line at one time, while gpsd is an open standard and supports multiple clients...

How do you run/use demo4....step-by-step instruction would be helpful...

That's excellent news. Any ideas as to how they will be addressing it ?

Just wondering if they are fixing buggy/poor implimentation of some part of the softwre or are adding some enhancement such as AGPS.

Also, anyone actually got hold of an N810 WiMax yet ? Would love to know what the differences between new/old Wayfinder are.

I'm hoping they have changed the way they offer downloads for traffic etc. since at the moment, I can't get updates via my my phone (T-Mobile UK). Traffic updates was one of the main temptations to get me to buy it

I know the connection is fine, since Maemo Mapper works great with it

Zuber

It is A-GPS type improvement.

My fix times have ranged from just under a minute to around 5 minutes. Most fixes occur under 2. No idea why the randomness-- I am usually in a 30 foot radius of the same location.

That is impressive- Sometimes I have never been able to get a fix, although that hasn't happened since I started employing my manual disable/enable the "enable gps" setting and restart technique. I would guess that on average my wait time is around 4 mins.

I only use wayfinder's sw though.

We live at a fairly high elevation in a mostly flat land (Dallas/Fort Worth). I wonder if that helps...