Future of location services on OM

[Dima Kogan]

Look around their site; everything's pretty clear.
http://www.opencellid.org/ requires you to register to update the
database, but not to query it. The api is at
http://www.opencellid.org/api . The raw data is at
http://www.opencellid.org/data/

The script appears below, but it's a hack at the moment. I couldn't
find an FSO method to get the cell tower id, so I'm tailing the log to
get it instead. Also, I'm using the agps-onlinec app from the wiki to
actually seed the AGPS. This writes directly to /dev/ttySAC1, which
really is not the right way to do it in FSO-land. Still seems to work,
though. You also need an account with u-blox to get the ephemeris and
almanac data. These are free and instructions are on the wiki.

dima



On Sun, 11 Jan 2009 01:05:09 +0100
Stefan Schmidt <stefan at openmoko.org> wrote:

> Hello.
> 
> On Sat, 2009-01-10 at 07:48, Dima Kogan wrote:
> > There are several free databases of GSM tower locations. I wrote a
> > perl script that I run on my gta02 to query
> > http://www.opencellid.org/ for the approximate tower location, and
> > then initialize the AGPS with this data. Works great. The database
> > is built from user submissions, so it's not complete, but it will
> > grow.
> 
> Haven't found this one yet, looks interesting.
> 
> As you already used it you may could answer some questions the
> website did not cover. What is the actual license? They write
> creative commans and the link points to the project side. Is it by-sa
> mentioned on the website or is this for the website content?
> 
> Are there dumps of the db or is it only available via a http query? I
> ask because I would prefer to have it directly on the phone, without
> internet connection.
> 
> As I said, looks like the most promising candidate so far. :)
> 
> Any chance to share your script?
> 
> regards
> Stefan Schmidt
> 
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> devel at lists.openmoko.org
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#!/usr/bin/perl -w
use strict;

my username
$ublox_username = BLAH;
$ublox_password = BLAH;

open(FSOLOG, "grep cid /var/log/frameworkd.log | tail -n 1 |");
my $regline = <FSOLOG>;
defined $regline && length($regline) or die("couldn't grab log line\n");
close(FSOLOG);

# keep only the data inside {}
$regline =~ s/.*{(.*)}.*/$1/;

my ($mcc, $mnc, $lac, $cid);
while($regline =~ /'([\S]+)':\s+([\S]+),/g)
{
  my ($key, $value) = ($1, $2);
  $value =~ s/.*'(.*)'.*/$1/;
  if($key eq 'code')
  {
    $value =~ /^[0-9]+$/ or die("code not numerical\n");
    ($mcc, $mnc) = $value =~ /^([0-9]{3})([0-9]*)/;
  }
  elsif($key eq 'cid')
  {
    $value =~ /^[0-9a-fA-F]+$/ or die("cid not hex\n");
    $cid = hex($value);
  }
  elsif($key eq 'lac')
  {
    $value =~ /^[0-9a-fA-F]+$/ or die("lac not hex\n");
    $lac = hex($value);
  }
}

my $celldataHeader = qr{<rsp stat="ok">};
my $celldataFooter = qr{</rsp>};
my ($lat, $lon, $pac);

my $url = "http://www.opencellid.org/cell/get?mnc=$mnc&mcc=$mcc&lac=$lac&cellid=$cid";
print "$url\n";

open(CELLDATA, "wget -q -O - '$url' |");
while(<CELLDATA>)
{
  next unless /$celldataHeader/ .. /$celldataFooter/; # only leave header, footer, everything inbetween
  next if /$celldataHeader/ || /$celldataFooter/;     # toss header and footer

  ($lat) = /lat="([\d\-\.]+)"/ or die("couldn't parse latitude\n");
  ($lon) = /lon="([\d\-\.]+)"/ or die("couldn't parse longitude\n");
  ($pac) = /range="([\d\-\.]+)"/;

  if(!defined($pac) || $pac > 100)
  {
    $pac = 20000;
  }
  else
  {
    $pac = 2000;
  }
}
close(CELLDATA);

defined $lat && defined $lon && defined $pac or die("lat, long, pac not all defined\n");
my $cmd = "~/agps-onlinec -c full -u $ublox_username -k $ublox_password -la $lat -lo $lon -p $pac";
print "$cmd\n";
system($cmd);