How the Google Phone Works

A cropped image of a driver using a map on a phone. — The HTC G1 is the first phone to feature the Google Android OS. sukanya sitthikongsak / Getty Images

In 2007, people began to circulate rumors that the Google corporation would introduce a smartphone to compete with Apple's iPhone. Speculation ran rampant -- would Google get into the hardware business? Would the company rely on established cell phone manufacturers for hardware? Would Google simply concentrate on building smartphone applications for other devices like the iPhone?

Google executives claimed that the company wasn't interested in building hardware. But some Web journalists and bloggers remained unconvinced. By early 2008, it became clear that the Google executives had been straightforward all along -- Google wasn't getting into the handset hardware game. But they were getting into the handset software business with a mobile operating system (OS) called Android.

Unlike the Apple iPhone, which has its own OS exclusive to the iPhone's hardware, Google's approach was to create an OS that could work on phones built by different manufacturers. Additionally, no single service provider would have exclusive rights to use the Android platform. In that respect, Android joins other mobile device operating systems like Symbian and Windows Mobile.

The first Google phone was the G1, a handset manufactured by a company based in Taiwan called the High Tech Computer Corporation (HTC). The first service provider to support Android in the United States was T-Mobile. As the OS debuted in the United States, other handset manufacturers announced plans to develop their own Android phones.

In January 2010, Google unveiled the Nexus One. This Android phone was the first handset you could purchase directly from Google. Like the G1, HTC provided the hardware for the Nexus One. Customers could choose to buy the phone for $179 if they signed up with T-Mobile for a two-year contract or $529 for an unsubsidized phone without a contract.

An important factor that sets Android apart from most other mobile operating systems is that it's based on an open source platform. That means Google allows anyone to look at and modify most of Android's source code. Ideally, this would mean that if a developer felt Android needed a specific feature or capability, he or she could build it and incorporate it into the OS. The software would constantly evolve.

Initially, the Android platform didn't support many of the features of other smartphone operating systems. For example, Android offered no Microsoft Exchange support upon release. Many companies use Microsoft Exchange as a platform for e-mail and scheduling applications. But because of the open source nature of Android and Google's support for third-party developers, it didn't take long before a company offered an application that would sync Exchange functions with the phone. The Android platform may have to play catch up with the other operating systems on the market, but it may have the ability to go even farther.

On the next page we'll introduce you to the Nexus One Google phone.

Google Phone Features

Several handsets use the Android operating system. There's the HTC G1, the first smartphone to run on Android in the United States. Verizon offers the Droid, an Android phone built by Motorola. Several other phones also rely on Android but the Nexus One is the first true Google phone -- the first phone you can purchase directly from Google.

When Google first issued Nexus One models to its employees, the handsets had no manufacturer markings on the case [source: Abramson]. Once Google offered the phone to the general public, the hardware included an HTC logo.

The Nexus One is 4.7 inches (119 millimeters) tall, 2.4 inches (59.8 millimeters) wide and less than half an inch (11.5 millimeters) thick. It weighs just 4.6 ounces (130 grams) with the battery installed. It has a 3.7-inch (about 9.4-centimeter) active matrix organic light emitting diode (AMOLED) display. The display resolution is 800 by 400 pixels and its contrast ratio is 100,000 to 1.

The phone uses a 1 gigahertz Qualcomm processor and has 512 megabytes of RAM. It also has 512 megabytes of Flash memory and comes with a four-gigabyte micro SD storage card. Nexus One owners who want more storage can upgrade up to a 32-gigabyte SD card.

The phone works on the 850, 900, 1800 and 1900 megahertz frequencies on GSM/EDGE cellular networks. It also has a Wi-Fi receiver that is compatible with 802.11 b and g protocols. The phone supports Bluetooth 2.1 and A2DP stereo Bluetooth. It also has an assisted global positioning system receiver.

The phone's 5-megapixel camera comes with an LED flash. It also has a digital zoom feature that provides a zoom power of 2X. The camera can take video at 20 frames per second with a resolution of 720 by 480 pixels.

The Nexus One launched with the Android operating system version 2.1, codenamed Éclair. This version of the OS supports multiple contacts and synchronization applications, allowing developers to create apps that let users manage several e-mail accounts using one device.

Anyone wanting to buy an Android phone will have to create a Google account first. Google accounts are free and you can sign up at any time whether you own an Android phone or not. If you have a Google account, you can access services like Gmail, Google Calendar and Google Docs. Android's designers built the platform so that it interfaces with these functions smoothly.

As hardware becomes more advanced, Google is likely to tweak the Android OS to support new features and functions. And if Google doesn't do it, someone else will. That's the beauty of an open-source system.

What makes Android tick? Read on to find out.

The First Android Handset

The HTC G1 sports a 3.2-inch (8.1-centimeter) LCD touchscreen, a GPS receiver, an accelerometer, an electronic compass, a 3.2 megapixel camera and WiFi, and 3G connectivity capability. The screen slides to the side to reveal a full QWERTY keyboard. The handset also has a storage card expansion slot. One thing it doesn't have is a standard headphone jack -- you have to use a USB adapter if you want to use your headphones. Since the phone has a media player, many reviewers felt the lack of a standard jack was one strike against the device.

Google Android Architecture

Google usually refers to the Android OS as a software stack. Each layer of the stack groups together several programs that support specific operating system functions.

The base of the stack is the kernel. Google used the Linux version 2.6 OS to build Android's kernel, which includes Android's memory management programs, security settings, power management software and several hardware drivers. Drivers are programs that control hardware devices. For example, the Nexus One has a camera. The Android kernel includes a camera driver, which allows the user to send commands to the camera hardware.

The next level of software includes Android's libraries. You can think of libraries as a set of instructions that tell the device how to handle different kinds of data. For example, the media framework library supports playback and recording of various audio, video and picture formats. Other libraries include a three-dimensional acceleration library (for devices with accelerometers) and a Web browser library.

Located on the same level as the libraries layer, the Android runtime layer includes a set of core Java libraries -- Android application programmers build their apps using the Java programming language. It also includes the Dalvik Virtual Machine.

A virtual machine is a software application that behaves as if it were an independent device with its own operating system. You can run a virtual machine on a computer that operates on a completely different OS than the physical machine's OS. The Android OS uses virtual machines to run each application as its own process. That's important for a few reasons. First, no application is dependent upon another. Second, if an application crashes, it shouldn't affect any other applications running on the device. Third, it simplifies memory management.

The next layer is the application framework. This includes the programs that manage the phone's basic functions like resource allocation, telephone applications, switching between processes or programs and keeping track of the phone's physical location. Application developers have full access to Android's application framework. This allows them to take advantage of Android's processing capabilities and support features when building an Android application. Think of the application framework as a set of basic tools with which a developer can build much more complex tools.

At the top of the stack are the applications themselves. This is where you find the basic functions of the device such as making phone calls, accessing the Web browser and accessing your contacts list. If you're an average user, this is the layer you'll use most. You do that with the user interface. Only Google programmers, application developers and hardware manufacturers access the other layers further down the stack.

You can change the way your Google Phone works by downloading applications to it. Read about a few of them on the next page.

Google Phone Applications

These days, it's not enough for your smartphone to be able to check e-mail and surf the Web as well as make phone calls. You need to have at your disposal a host of useful, fun, productive or just plain pointless applications. The iPhone's success has proven that a strong application library can excite customers. Google's Android platform appears to be following suit.

Months before the HTC G1 hit the shelves, Google unveiled the Android platform to developers. The company created a limited software developer kit (SDK) and distributed it to developers. Google even laid down the Android Developer Challenge -- a contest that had a collective prize pool of $10 million.

The top developers earned $275,000 for their applications. Here's a small sample of what made the grade:

CompareEverywhere and GoCart are two different applications that let you compare prices and read reviews for merchandise while you're in the store. You take a picture of the item's bar code with the phone's camera. These applications identify the item and aggregate reviews and prices from different sources.
The Life360 application is part social networking, part news service. It lets you set up a neighborhood-centric online community and share information with other people in that group. It can alert you of emergencies like a tornado warning that affects your neighborhood. Even if you are miles away, you can keep up with what's going on back at home.
Locale is an application that taps into Android's GPS support. First, you identify various locations you frequent using Google Maps. Then, you create a list of phone settings for each location. For example, at work or in class you'd probably want your phone's ring tone to be appropriate and at a low volume. Once you create the settings for each location, your phone automatically switches to the proper setting based on your current location. Using Locale, you never have to worry about silencing your phone when you walk into your favorite movie theater!
For the green-conscious, there's Ecorio. This application tracks your global carbon footprint and offers suggestions to reduce your personal impact on the environment. You can use the Google Maps application to plot out a trip and Ecorio offers suggestions for car pooling, public transportation and other tips to create the smallest ecological impact.
The developers of the Softrace application wanted to build a program that inspires people to maintain an active lifestyle. Softrace lets people set up footraces, bicycle races and other competitions using the Google Maps function. Participants can travel to a race destination, begin the race and try to make the best time. They can compare their results with those of other participants.

There are many more Android applications in the $275,000 winners' circle and beyond. And several developers for some of the better-known iPhone applications have expressed interest in developing an Android version of their apps. While the iPhone has a head start, Android has the potential to equal and perhaps even surpass it on the application front.

So how do these developers build applications for the Android? We'll learn more about the application development process in the next section.

Building Android Applications

To build an Android application, a developer has to be familiar with the Java programming language. Assuming the developer is proficient in Java, he or she can download the software developer kit (SDK) and get started. The SDK gives the developer access to Android's application programming interface (API).

The SDK includes several tools, including sample applications and a phone emulator. Emulators are programs that duplicate the features and functions of a specific system or device. The Android emulator is a program that duplicates the functions of a phone running on the Android platform. When the developer finishes building an application, he or she can test it out on the emulator to see how the app will perform on actual hardware.

Google provides an extensive Android tutorial on its developer Web site. The company even provides tips on basic programming steps like testing and debugging software. Experienced developers can skip over the tutorial and go straight to building an application. Google even provides step-by-step instructions on how to build an application named Hello World to give developers the chance to become familiar with Android's architecture.

This brings us to another feature of Android that sets it apart from the iPhone -- developers can create complex applications that run in the background of other applications. Apple limits iPhone applications to the foreground -- if you switch to a different application, the first application you were in stops working until you return to it. This feature limits the types of applications developers can build for the iPhone. Android allows developers more extensive access to background processes.

Google breaks down all applications into four basic building blocks (not all applications will have every building block):

Activities: Whenever an application displays a screen to the user, that's an activity. For example, a map application could have a basic map screen, a trip planner screen and a route overlay screen. That's three activities.
Intents: Intents are the mechanisms for moving from one activity to another. If you were to plot a trip using our example of the mapping application, an intent would interpret your input and activate the route overlay screen. Android also allows for broadcast intent receivers, which are intents triggered by external events like moving to a new location or an incoming phone call.
Services: A service is a program that runs on its own without a user interface. For example, let's say you are participating in a Softrace event. Midway through the race, you decide you want to listen to music as you burn up the track. You can switch over to a media player application and start a song while Softrace continues to track your progress. If Softrace were simply an activity, you would have ended the application as soon as you switched to the media player.
Content provider: A content provider allows an application to share information with other applications. This allows developers to work together to create a suite of applications that are more robust and complex than each individual component.

There are other considerations developers must keep in mind while building applications. They include Android's graphics rendering engine, process management software, user interface support and other technical details. Google provides guides for all of these elements on its Android developer Web site.

The journey of the Google Phone has not always been a smooth one. Some vendors have been quick to accept the OS, while others have dismissed it. Let's take a look at who is and who isn't thrilled about Android.

Google Mobile Phone Vendors

There are two kinds of vendors you have to consider when you talk about a smartphone operating system: the handset manufacturers and the cell phone service providers. Handset manufacturers produce the actual hardware. Service providers are the phone companies like T-Mobile or AT&T. Some handset manufacturers work exclusively with a specific cell phone provider. In a few cases, a cell phone service provider will also produce its own hardware.

As we mentioned earlier, the first handset to feature the Android OS was the High Tech Computer Corporation's HTC G1. Before the phone even went on sale, bloggers and journalists began to speculate on who would be the next handset manufacturer to get into the Android game. Gradually, other companies like Motorola, Samsung and Dell debuted their own Android handsets.

The first cell phone provider in the United States to support an Android phone was T-Mobile. The company first offered the HTC G1 on its 3G network to customers in October 2008 for $179 with a contract. A month earlier, T-Mobile offered current customers the opportunity to reserve an HTC G1 in advance. The pre-sale was a huge success -- T-Mobile had to end the sale early when orders exceeded the company's stock of 1.5 million phones [source: Bylund].

But some cell phone service providers have gone so far as to criticize the Android OS in public. Sprint CEO Dan Hesse said that Android wasn't "good enough to put the Sprint brand on it" [source: Carew]. Hesse did leave open the possibility that Sprint would work with the Android platform in the future. Meanwhile, Peter Michaels, the CEO of Hop-on, criticized Hesse's statements. Michaels alleged that Sprint makes it hard for inexpensive handset vendors to join its network. He also pointed out that Sprint was a founding member of the Open Handset Alliance -- a project that spawned Android. But Michaels said that while the company says it supports open platforms, its actions seem to contradict those claims [source: Hop-on].

Hesse must have changed his mind about the Android operating system. Sprint now supports the HTC Hero and the Samsung Moment, both Android phones.

Verizon debuted two Android phones in 2009: the Motorola Droid and the HTC Eris. AT&T announced at the beginning of 2010 that it would soon carry Android phones made by HTC, Motorola and Dell.

With Android spreading to all major cell phone carriers across the globe, we may see Google dominate the mobile phone market the same way it has for online search. Maybe this is the droid you're looking for.

To learn more about the Google Phone and related topics, dial up the links on the next page.