Friday, November 30, 2007

Location technologies: Differences and similarities

There are at least 4, 5 different ways for you to find out where someone (or a device) is currently located:

Satellite based GPS

This is the free, radio signal based one. Satellites up our heads beeping signals in a constant frequency that can be picked up by GPS (radio) receivers.

You need a device which actually "listens" to the GPS radio signals to get it. They need to carry chipsets providing a combination of RF components and software to correlate and process the location data into latitude, longitude and altitude plus time values.

Phone Carrier based Assistance to GPS signaling

With E911 requirements, carriers were obligated to provide progressively more accurate location information in emergencies to cell phone users.

There are basically two main ways to broadcast digital signals to multiple cell phone receivers: GSM and CDMA.

CDMA radio signals as those broadcasted by the GPS satellites, have a time-stamp signature. This is the key data for trilaterating (also referred to as triangulation) three or more points for determining location of a given receiver.

Assisted GPS combines triangulation results from a cell phone obtained from the time a signal takes to reach it from the cell towers; to the GPS data of known locations.

Being a time-based network CDMA allows for more precise determination of a cell phone and its user. GSM provides a much lower precision and there are attempts to improve its resolution through methods like Enhanced GPS for example.

Cell Tower ID databases

Another approach is to create and refer to a database of cell towers id's to obtain its corresponding location (latitude/longitude). For that customers knowingly (or unknowingly) provide the data to seed a database.

Google Maps for Mobile uses this approach with its My Location feature.

There are several open databases with id's of GSM towers used in U.K. and Europe.

Wi-Fi MAC addresses databases

In heavily populated areas, the use of data from wireless access points associated to their corresponding location extends the Cell Tower database approach.

This technique was used by PlaceLab a lab sponsored by Intel. Navizon has been doing this for a while now and before them Wigle and its open source database.

(Static) IP address can also be used for location.

And there are also proposed standards and implementations of GPS data transport protocols which opens lots of possibilities.

What do you got?

So based on this you have GPS or more precisely Location data depending on how manufactures, developers and phone companies decide what is available for you as customer.

In cell phones some sort of E911 will be available. This can be implemented in several forms. For example, CDMA carriers use a Position Determination Entity, or PDE Server that keeps track of devices location.

Privacy concerns should abound here and in any other case where private data is kept.

Thursday, November 29, 2007

Crack and Cell Tower Databases

That's it. First round is over. Verizon opens up. Second still going. FCC deadline for the bidding of the 700 Mhz spectrum is Dec 3rd. Will Google blink? Check DailyWireless for inside info.

Also, My Location is about sending true location data (accurate Lat/Long) to a database of Cell Tower ID's for those devices that don't have access to GPS radio data. Andrew Grill explains well.

Thursday, November 08, 2007

Cracking the Carrier Lockdown

Mobile phones are getting an evolutionary jolt these last weeks thanks to:

  • customer response to the materialization of their gadget desires with the iPhone (and Nokia's N95);
  • the realization that carriers can't lock down the mobile platform forever and
  • the possibility of open source-ness through Linux-based alliances thanks to a well-orchestrated PR by Google.
And don't fool yourself: the main goal behind all of this show from Google is to allow you to see localized ad's on the screen of your cell phone.

Talking Google, their LBS API's win the hearts and minds of developers despite all the smoke and mirrors.

Android: The New Borg

Some dots to consider with Android. It was developed by Andy Rubin which created what became the SideKick at Danger. It runs its own version of Java.

But next week is around the corner, so let's wait to see what this thing actually looks like.

In the same vein, Wired, NYTimes and Slashdot hammered carriers and their crippling practices.

LBS for Social Networks, API's

One of the ways LBS can happen is by helping "social networks" as shown this year at CTIA [CNet articles] exemplified by Rummble, Whrll, Utterz, Socialight in UK and Trutap.

You might have heard of the Google API for Social Networks (which includes GeoRSS location info as pointed out by ProgrammableWeb) despite better and more mature ideas being around.

And I remember reading somehere a suggestion that the move shows that Google could be afraid of Facebook.


Talking about development stacks, check SirfStudio and SirfSandbox: a collection of libraries and tools for Java and C++ development of GPS-based applications.

That if you want to develop and deploy LBS applications to be used this year.

GPS Data, Privacy, Choice

NYTimes on Privacy: "These phones can find you"

Do you want to broadcast your location?
ITWeek talks about FireEagle from Yahoo (still in alpha)

Ticket fought with GPS evidence. [Update: But judge didn't take it.]

Meanwhile, GPS chips on cell phones ramping up, via EETimes on a heated up market according to manufactures.

And TruePosition study discovers what users want from LBS.

DIY: Open Source Phones, GPS Loggers, Virtual BIOS

Trolltech announced the decision to stop development of its Greenphone (CNet, Slashdot).

OpenMoko is the game now which has a partnership with the same TrollTech.


New Lego-like kit for GPS equipped DIY hardware. ARM11 based from Bug Labs. Via LinuxDevices.

Elektor published an expensive GPS/GSM tracking project

And Hack a day keeps hacking... Build a GPS/Glonass receiver, GPS loggers, trackers...

Virtual BIOS

Major Development from where you would never expect: Phoenix BIOS is bringing virtualization to hardware so you can open your notebook and count to four before hitting the first key.

The idea behind "HyperSpace" is to virtualize the booting process by storing memory images and loading them up so you can choose which OS to use.

Takahashi describes at the Mercury News how Phoenix will provide this mechanism for new PC's as soon as 2008.

Map Biz, Dash Mashups, N95 Guts

Garmin ups the hand, TomTom covers it and TeleAtlas accepts the bid.

Darpa driverless cars have another round (at EETimes, GPSWorld),

Gizmondo shows Dash mashups, your upcoming mobile tv taking shape in a new gadgetized distraction.

EETimes shows what is the Nokia N95 made of including its Texas' NaviLink GPS5300 chipset. True one then, with Assisted-GPS software based support.

At CTIA 2007 Qualcomm announced Gobi "a global mobile Internet hardware and software combination for notebooks [...] with embedded GPS capabilities".

Friday, November 02, 2007

Mio Digiwalker for $150 at RadioShack

Not sure what is the catch... 15k units available as of 10/31.

[Update: Fry's ads offer the Holux GPSMile-52 [newer model 55 page at Holux] for about the same.]