How GPS Phones Work

by Tracy V. Wilson
Imagine driving to a job interview and realizing that you're lost. Your first impulse would probably be to call the business that's interviewing you and ask for directions. But if you're not sure where you are, getting directions can be tricky.
But suppose you use your phone for another purpose -- to figure out exactly where you are and to get turn-by-turn directions to where you're going. New phones that include global positioning system (GPS) receivers can do exactly that. With the right software or service package, they can pinpoint your location, give directions to your destination and provide information about nearby businesses.
In this article, we'll review the basics of how cell phones and GPS receivers work. Then, we'll explore how phones combine these technologies.
Cell Phone BasicsA cell phone is basically a sophisticated two-way radio. Towers and base stations, arranged into a network of cells, send and receive radio signals. Cell phones contain low-power transmitters that let them communicate with the nearest tower.
As you travel, you move from one cell to another, and the base stations monitor the strength of your phone's signal. As you move toward the edge of one cell, your signal strength diminishes. At the same time, the base station in the cell you are approaching notices the strength of your signal increasing. As you move from cell to cell, the towers transfer your signal from one to the next.
In remote locations, towers may be so far apart that they can't provide a consistent signal. Even when towers are plentiful, mountains and tall buildings can interrupt their signals. Sometimes people have a hard time getting clear signals inside buildings, especially in elevators.
­ Even without a GPS receiver, your cell phone can provide information about your location. A computer can determine your location based on measurements of your signal, such as:
· Its angle of approach to the cell towers
· How long it takes the signal to travel to multiple towers
· The strength of your signal when it reaches the towers
Since obstacles like trees and buildings can affect how long it takes your signal to travel to a tower, this method is often less accurate than a GPS measurement.­­
GPS Receiver Basics
Like a cell phone, a GPS receiver relies on radio waves. But instead of using towers on the ground, it communicates with satellites that orbit the Earth. There are currently 27 GPS satellites in orbit -- 24 are in active use and 3 act as a backup in case another satellite fails.
In order to determine your location, a GPS receiver has to determine:
· The locations of at least three satellites above you
· Where you are in relation to those satellites
The receiver then uses trilateration to determine your exact location. Basically, it draws a sphere around each of three satellites it can locate. These three spheres intersect in two points -- one is in space, and one is on the ground. The point on the ground at which the three spheres intersect is your location.
A GPS receiver has to have a clear line of sight to the satellite to operate, so dense tree cover and buildings can keep it from getting a fix on your location.
GPS receivers and cell phones have a lot in common, and both are very popular. In the next section, we'll look at some of the features of GPS-enabled cell phones.
GPS Phones
Nearly all new cell phones sold in America have some GPS receiving capability built in. Those that don't can connect to a server that uses techniques discussed in the last section to analyze their signals and determine their location. This allows the phones to transmit a person's location to a Public Safety Answering Point (PSAP) after dialing 911. But that's all a lot of phones can do with their GPS.
However, some phones have a complete GPS receiver located in the phone or can connect to one with wires or through a Bluetooth connection. These GPS-enabled phones can understand programming languages like Java and can provide turn-by-turn directions or information about nearby businesses and attractions. Others can work like a tracking device. To use any of these features, you must have:
· A GPS-enabled phone or a compatible GPS receiver
· A calling plan that supports transmission of maps and GPS data
· A service plan or software that provides the actual maps and directions or provides information about the phone's location
Common uses for GPS phones include:
· Location Tracking: Some employers use GPS-enabled phones to track their employees' locations, and some business offer location tracking services for GPS-enabled phones. The Wherifone locator phone provides GPS coordinates and can dial emergency phone numbers. Parents and caregivers can track the phone's location by phone or online and can receive notification if it leaves a designated "safe area." Wearable Environmental Information Networks of Japan has also introduced the Dog @ Watch, a GPS watch phone for children.
· Turn-by-Turn Directions: GPS-enabled phones with view screens can often display turn-by-turn directions as well as announce them through the phone's speaker. In general, companies that offer these services charge a monthly fee and use a database of maps to provide the directions. The services are only as good as their database -- outdated maps can provide inaccurate directions. Some turn-by-turn direction services include:
o TeleNav
o ViaMoto
o MapQuest Find Me
o smart2Go, which requires a separate Bluetooth GPS receiver and a memory card
o Destinator SP, which is a software package for smartphones
· Outdoor Location Services: Trimble Outdoors offers maps and location-based services for hiking, mountain biking, geocaching and other outdoor activities.
· Other Location-Based Services: Some companies hope to deliver news, coupons, advertisements and other information to cell phone users based on their location.
Some other GPS-enabled phones include:
· Mio A701 Smart Phone
· Several Motorola phones offered through Sprint/Nextel
Follow the links on the next page for lots more information about cell phones, GPS systems and related technology.
Related HowStuffWorks Articles
· How GPS Receivers Work
· Cell Phone Quiz
· How Cell Phones Work
· How Buying a Cell Phone Works
· How Smartphones Work
· How Cell-phone Radiation Works
· How Radio Works
· How Microprocessors Work
· How Telephones Work
· How Intelligent Highways Will Work
· How Satellites Work
· How Location Tracking Works
· How Compasses Work
More Great Links
· GPS Cell Phone
· Global Positioning System Overview
· Cellular Telephone Basics
· Wireless-Assisted GPS
· GPS World
Sources
· Aquino, Grace. "GPS Phone Leads the Way." PCWorld, June 2004. http://www.pcworld.com/reviews/article/0,aid,115893,00.asp
· Ellison, Carol. "GPS Phone to Take the Stage at CTIA." eWeek.com, March 10, 2005. http://www.eweek.com/article2/0,1759,1774953,00.asp
· "GPS-Enabled Cell Phones Taking Off." TechWeb, September 16, 2004. http://www.techweb.com/wire/mobile/47212213
· "New GPS to be Built into Cell Phones, Study Says." InformationWeek, May 13, 2005. http://informationweek.com/story/showArticle.jhtml?articleID=163101789
· Hamblen, Matt. "Don't Count on Using your Cell Phone for Disaster Rescue." PC World, July 7, 2005. http://www.pcworld.com/news/article/0,aid,121744,00.asp
· Aquino, Grace. "Phones Use GPS to Show You the Way." PC World, August 2005. http://www.pcworld.com/news/article/0,aid,121417,00.asp
· Levy, Steven. "A Future with Nowhere to Hide?" Newsweek International, June 7, 2005. http://www.msnbc.msn.com/id/5093170/site/newsweek/
· Rojas, Peter. "Garmin Brings GPS to a Handful of Sprint Phones." Engadget, September 8, 2005. http://www.engadget.com/entry/1234000667057924/
Source : http://electronics.howstuffworks.com/gps-phone1.htm

Samsung M320 - red (Sprint)

If you're looking for a low-end camera phone with a simple design, you can always count on Samsung. The company spins them out fast and furiously in the United States, particularly in the run-up to the holiday season. The Samsung SPH-M320 for Sprint is the newest model to fit this mold. Its design is minimalist and easy to use, and it offers a quality VGA camera. On the downside, the call quality is variable, and the display is a little two low-res for our tastes. But, in the end, it's not a bad handset for occasional callers. Alternatively, if you want the basic functionality without the shooter, the SPH-M220 is the SPH-M320's cameraless counterpart. The M320 is just $19.99 with service.
DesignThe SPH-M320 has a standard flip-phone design, but that doesn't mean it doesn't have its good points. The red color is attractive, and the light-catching mirror goes easy on the fingerprints and smudges. At 3.6 inches tall by 1.86 inches wide by 0.85 inch deep, and weighing 2.68 ounces, the phone is also slim, lightweight, and compact. The handset feels comfortable in the hand, and the hinge is sturdy, but the plastic skin feels a tad flimsy.
The external display is no bigger than a postage stamp, but it shows all the information you need, including the date, time, battery life, signal strength, and numeric caller ID. And with support for 65,000 colors (96x96 pixels), it also shows photo caller ID and works as a viewfinder for the external display, which sits just above. You can choose from a few clock styles and adjust the contrast. The remaining exterior controls include a volume rocker and a micro-USB port on the left spine, and a 2.5mm headset jack and a camera shutter on the right spine.
The SPH-M320's internal display measures a sizable 1.8 inches, but it supports just 65,000 colors (128x145 pixels). On a phone without a camera we wouldn't really mind, but even a handset with a VGA shooter deserves a higher-resolution screen. Colors were relatively bright and the menus are simple, but graphics and photos were far from sharp. You can change the backlighting time, the brightness, and the dialing-font size and color.
We very much approved of the SPH-M320's navigation array and keypad. Both have spacious layouts with tactile buttons. What's more, the numbers on the keys are large and the backlighting is bright. On the array there's a four-way toggle with a central OK button, two soft keys, Talk and End/power controls, and a back key. The toggle doubles as a shortcut to four features of your choice.
FeaturesThe SPH-M320's phone book holds 499 contacts, with room in each entry for five phone numbers, a URL, an e-mail address, a nickname, and notes. You can assign callers to groups and pair them with a photo and one of 20 polyphonic ringtones. Alternatively, you can compose your own ringtones using the integrated voice recorder. Other essentials include a vibrate mode, text and multimedia messaging, a calendar, a scheduler, a task list, a countdown timer, a memo pad, a world clock, an alarm clock, and a calculator.
Though it is miles from being a smartphone, the SPH-M320 offers a couple of extra options. Inside you'll find Bluetooth, voice dialing, and an airplane mode. It also offers instant messaging and browser-based POP3 e-mail. The latter isn't the most user-accessible experience, but it works in a pinch.
Reviewed by: Kent GermanSource : http://reviews.cnet.com

Blackberry® Bold™

Some matters if you wish to know about Blackberry Bold, follow this information.
The BlackBerry® Bold™ smartphone is a symbol of what you’ve already accomplished – and the achievements still to come.
Discover Pure Innovation
Power the passions you pursue with a smartphone that expresses your style and simplifies your life.
The BlackBerry® Bold™ smartphone embodies elegant design — without sacrificing the features or functionality you expect from a premium smartphone.
Learn about the BlackBerry Bold smartphone features.
Feature :The BlackBerry® Bold™ smartphone is pure innovation. Discover how it can power the passions you pursue.
The BlackBerry Experience: No Compromises
With email, phone, IM and the Internet, it can connect you1. With an integrated organizer, it can help you stay on top of your day. With camera and video recording2, you can capture and share the moment with just a few clicks.
And that’s just the beginning. Learn about these great features:
Email
Advanced Phone Features
Instant Messaging
Internet Browser
Camera and Video Recording
Wireless Modem
Fast Performance
Do more - do it faster. The BlackBerry Bold smartphone was designed to take advantage of the speeds available on the HSDPA network1,3. Together, this high speed network and the 624-MHz processor help support your need to multitask and prioritize with access to your voice and data services at the same time.
Multimedia
The fun goes with you. Enjoy premier image and video viewing, build playlists of your favorite songs and organize your media files. You can even use BlackBerry® Media Sync to transfer desktop iTunes® music files to your smartphone. The BlackBerry Bold smartphone delivers a wealth of entertainment. Learn more about media on your BlackBerry Bold smartphone:
Media Player
BlackBerry Media Sync
Roxio Media Manager
GPS and BlackBerry Maps
Know where you stand. With built-in GPS capabilities, and BlackBerry® Maps, you get turn-by-turn directions, so you can pinpoint where you are right now and where you need to be1,4. Learn more about finding your way:
GPS Capabilities
BlackBerry Maps
Wi-Fi
Simple and straightforward. Lower your cellular costs and get service in areas where cellular network coverage may be limited or unavailable, with BlackBerry data services over Wi-Fi® networks.5
Wi-Fi Support
File Editing
With WordToGo and SlideshowToGo, you can work on Microsoft® Word and Microsoft® PowerPoint® slides while you’re on the go.1,6 Copy and paste, adjust font formatting and more.7 The stunning LCD display makes working on the go an invaluable option.
Mobile Streaming
The built-in mobile streaming capabilities on the BlackBerry Bold smartphone are designed so that you can watch online videos or listen to streamed music broadcasts.8 Access information and fun without using up the memory on your BlackBerry smartphone.
Mobile Streaming and other Browser functions
Brilliant Display
Color and clarity come to life. The screen of the BlackBerry Bold smartphone catches the eye and is designed to deliver color and clarity that exceed expectations. From the moment you turn it on, you’ll be blown away by explicit color and quality.
Power
With the BlackBerry Bold smartphone’s long-lasting, removable battery, you’ve got the power to get things done, whether you’re traveling, working away from the office or just on the go.4
Learn More
BlackBerry Bold Specifications
Where to Buy
1 Requires activation with data plan. 2 Depending on the amount of built-in memory available for use, a third-party microSD card may need to be properly inserted into the BlackBerry smartphone to enable the video recording feature. MicroSD cards may be sold separately.3 Actual speeds may vary by carrier and are dependent on network load.4 Only available where BlackBerry Maps service is available.5 Wi-Fi access may be blocked in certain locations. Users should also investigate the level of security available on any Wi-Fi network they are considering connecting to.6 Requires BlackBerry Enterprise Server v4.1.57 WordToGo does not support Microsoft Word 20078 The BlackBerry Bold smartphone is designed to access 3GPP RTSP mobile streaming websites. When streaming functionality is accessed via the WAP Browser, significant, additional charges may apply. Check with your service provider for supported features and services. 9 Results may vary. Network availability and coverage affect battery life and are dependent upon a number of factors, including location and transmission environment.
Source: na.blackberry.com

The BlackBerry® Storm™ 9530

The BlackBerry® Storm™ 9530 smartphone has the power and performance to drive your desires. Find out how you can connect to your world.
Easy Touch Screen Navigation
The BlackBerry Storm 9530 smartphone features a SurePress™ touch screen—an innovative, pressable touch screen that allows fast-navigating and accurate typing.
With a SurePress touch screen, typing is easy—simply touch the screen to highlight a letter and then press down to make that letter appear in your message or document. A subtle click lets you know the letter has been entered.
The SurePress touch screen also makes navigation a breeze. Like a mouse, your fingertip becomes the cursor as you navigate from application to application. To open an application, press down on the screen.
Get More Out of Your Day
The HSPA network and the BlackBerry Storm smartphone’s 528-MHz processor combine to support your need to multitask and prioritize without falling behind or out of touch. Designed to provide you with access to your voice and data services at the same time, it helps you get more out of every day.1
Take phone calls while sending and responding to email or browsing the Internet
Maintain GPS-based directions or maps on your display even while taking a call
Snap the perfect picture and send it out even when you’re already on the phone
Discuss and revise Microsoft® Word, Microsoft Excel® and Microsoft® PowerPoint® files—edit while using the speakerphone2
Flexible Communications
You don’t stay in touch with all the people in your life in the exact same way. Stay on top of what’s happening and be available to the people who need you with high-quality voice and text-based communications options, including:
Wireless email for your personal/web-based and business accounts3
Advanced phone features such as voice activated dialing, conference calling, speakerphone and voicemail attachment playback4
Instant messaging and text messaging (SMS and MMS)3
Access to social networking sites like Facebook® and MySpace®3
World Phone Edition
The BlackBerry Storm 9530 smartphone is designed to roam globally on UMTS/HSPA and quandband EDGE/GSM/GPRS networks. So you can travel around the world with mobile voice and data coverage, without having to change smartphones, phone numbers or email addresses.
Camera and Video Recording
At 3.2 megapixels, you can take sharp, print-quality pictures using the BlackBerry Storm smartphone. You can also rely on the auto focus and auto flash to help you capture the moment.
And when an event can’t be captured in a single instant, use sound and action to tell part of the story with the video camera.5
Multimedia
Whether you want to watch a video clip or tune out the rest of the world by listening to your favorite songs, your BlackBerry Storm smartphone delivers visual and sound quality that keeps up with your needs.
1 GB of built-in memory—add up to 16 GB more using microSD cards6
Sync your desktop iTunes® music files using BlackBerry® Media Sync7,8,9,10
Use Roxio® Media Manager to help create your own personal juke box
GPS and BlackBerry Maps
The BlackBerry Storm smartphone features built-in Global Positioning System (GPS) capabilities. Designed to work with BlackBerry® Maps and other location-based software, use it to help determine where you are and how to get to where you need to be.3,11,12

Enjoy large, clear maps on the HVGA touch screen.
Mobile Streaming
Stay in the know even when you’re on the go with access to the mobile versions of news, television and other media sites. Interested in a funny clip from YouTube or the incredible play from last night’s game? The built-in mobile streaming capabilities on the BlackBerry Storm smartphone are designed so that you can watch online clips like these or even listen to streamed music broadcasts.13
Learn More
View the BlackBerry Storm smartphone specifications
1 Simultaneous voice and data connectivity is only available when the BlackBerry Storm smartphone is connected to a HSPA GSM network.2 Requires activation with voice and data plan.3 Requires activation with data plan.4 Requires activation with voice plan.5 Depending on the amount of built-in memory available for use, a third-party microSD card may need to be properly inserted into the BlackBerry Storm smartphone to enable the video recording feature. MicroSD cards may be sold separately.6 The BlackBerry Storm smartphone accepts microSD cards of various sizes; the amount of storage is determined by card capacity. MicroSD cards may be sold separately.7 For BlackBerry Media Sync to work your media enabled BlackBerry smartphone must be connected to your computer via a USB cable. Certain music files may not be supported by the media player, including incompatible file types and files that contain digital rights management technologies.8 BlackBerry Media Sync is compatible with devices featuring BlackBerry Device software v4.2 or higher. Devices that do not feature built-in mass storage capabilities (significant amounts of on-board memory) will require a microSD card to be properly inserted. Please visit www.blackberry.com/mediasync/microSD for a list of devices requiring microSD cards.9 BlackBerry Media Sync is compatible with 32-bit editions of Windows XP Service Pack 2 which can be used with iTunes version 7.0 or higher AND 32-bit editions of Windows Vista which can be used with iTunes version 7.2 or higher. Not compatible with Windows 2000 or MAC OS.10 All applicable charges will still apply for the purchase of music from iTunes. 11 For details services and their coverage areas visit www.blackberry.com/maps.12 Only available where BlackBerry Maps service is available.13 The BlackBerry Storm smartphone is designed to access 3GPP RTSP mobile streaming websites. When the streaming functionality is accessed via the WAP Browser, significant, additional charges may apply. Check with your service provider for supported features and services.Source (na.blackberry.com) Related post: mobile4U. mobile4U Info : Getting the first full touch screen BlackBerry smartphone? Crackberry has posted the BlackBerry Storm 9530 manual, you can download the 249 pages user manual first to know about the smartphone in detail! Click here to download the file (1.14 MB)