[hafqa] [hafqa] [Bug 2878] New: Very poor satellite acquisition in internal GPS

[From: bugzilla-daemon at lists.maemo.org]

https://bugs.maemo.org/show_bug.cgi?id=2878

           Summary: Very poor satellite acquisition in internal GPS
           Product: System software
           Version: 4.0
          Platform: N810
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: High
         Component: general
        AssignedTo: carlos at maemo.org
        ReportedBy: response at gmail.com
         QAContact: hafqa at maemo.org


SOFTWARE VERSION:
(Control Panel > General > About product)

OS2008 final

STEPS TO REPRODUCE THE PROBLEM:

The GPS in my N810 is very slow in acquiring satellites. Sometimes, it takes 5
minutes to obtain a fix even under these ideal conditions:

- Unobstructed sky on a sunny day
- Unit being held upright with nothing blocking the antenna
- Stationary position
- Fix obtained in the same position only a couple of hours earlier
- Plenty of satellites visible

For comparison, Holux M1000 bluetooth GPS reliably locks onto satellites in 30
seconds from a cold start, and in ~10 seconds after it has been off for an hour
or two.

My 4-year-old Garmin iQue 3600 and 10-year-old Magellan 150 handhelds are also
significantly faster in acquiring satellites.

This problem doesn't appear to be limited to my device. Lots of people on
internettablettalk.com and various blog sites have complained about poor GPS
performance.

Possible solutions the community would like to see from Nokia include:

- Please dump the Texas Instrument 5300 GPS chip from the next version of the
tablet. The industry standard in GPS technology these days is MTK, Sirf III,
and SkyTraq. These chips are small, cheap, and power-efficient enough that
there shouldn't be any excuse not to use them. Blackberry managed to fit a Sirf
III chip in their tiny Pearl2 phone.

- Please consider opensourcing gpsdriver and your version of gpsd. It is quite
possible that part of the problem lies in the software -- perhaps you do not
initialize the GPS correctly, or opt for cold starts when a warm/hot start is
more appropriate. Public scrutiny may help reveal such problems.

- If you cannot opensource the GPS interface, please consider allocating
additional resources within Nokia to examine this component more closely. Work
more closely with Texas Instruments to troubleshoot the issue.

- If TI chip supports AGPS, please enable this feature on internet tablets. 

EXPECTED OUTCOME:

Expected satellite acquisition time in almost any GPS device today is 30-60
seconds under good conditions. Once a lock is acquired and ephemeris data is
cached, subsequent locks should be even faster (as little as 2-5 seconds).

GPS devices should download and store almanac data. My impression is that N810
doesn't, since satellite positions are typically not known until a lock is
acquired.

ACTUAL OUTCOME:

Satellite acquisition times of up to several minutes even under ideal
conditions.

REPRODUCIBILITY:
(always/sometimes/once)

Almost always. Occasionally the GPS will lock in about a minute. 

EXTRA SOFTWARE INSTALLED:

OTHER COMMENTS:

GPS is a big reason why people choose N810 over N800 and pay a $250 premium.
Unfortunately, the GPS in N810 compares very poorly to other devices on the
market.

Bug 2877 may or may not be related to slow acquisition times.


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