How Smartphones Work

A Samsung Galaxy S5 (R) compared in size to a Galaxy S3 device. The S5 is significantly larger than its generation 3 predecessor. The new Galaxy S5 is the largest of the series and around 3 millimeters wider, 5 millimeters longer, and a fraction thicker than its predecessor. See more cell phone pictures.
A Samsung Galaxy S5 (R) compared in size to a Galaxy S3 device. The S5 is significantly larger than its generation 3 predecessor. The new Galaxy S5 is the largest of the series and around 3 millimeters wider, 5 millimeters longer, and a fraction thicker than its predecessor. See more cell phone pictures.
© Eduardo Barraza/Demotix/Corbis

Isn’t it great when science fiction becomes science fact? If you’re a little older, you probably wanted a communication device just like the one Captain Kirk used in the TV series “Star Trek” when you were growing up. Kirk and the crew of the USS Enterprise could talk over vast distances with these personal communication devices. Without the “communicator, the order to “beam us up, Mr. Scott” would have fallen on deaf ears, and we all know what would have happened to Kirk if he didn’t have any bars on his device.

Now that we’re well into the 21st century, our “communicators” make the ones on “Star Trek” seem like antiques. Not only can we talk to one another on our smartphones, but we can text, play music or a game, get directions, take pictures, check e-mail, find a great restaurant, surf the Internet, watch a movie. You get the idea. Smartphones are cell phones on steroids. Why is that?


Unlike traditional cell phones, smartphones, with their big old memories, allow individual users like you and me to install, configure and run applications, or apps, of our choosing. A smartphone offers the ability to configure the device to your particular way of doing things. The software in the old-style flip phones offers only limited choices for reconfiguration, forcing you to adapt to the way they are set up. On a standard phone, whether or not you like the built-in calendar application, you’re stuck with it except for a few minor tweaks. But if that phone were a smartphone, you could install any compatible calendar application you liked.

Here's a list of some of the additional capabilities smartphones have, from intuitive to perhaps less so:

  • Manage your personal info including notes, calendar and to-do lists
  • Communicate with laptop or desktop computers
  • Sync data with applications like Microsoft Outlook and Apple's iCal calendar programs
  • Host applications such as word processing programs or video games
  • Scan a receipt
  • Cash a check
  • Replace your wallet. A smartphone can store credit card information and discount or membership card info
  • Pay bills by downloading apps such as PayPal and CardStar
  • Allow you to create a WiFi network that multiple devices can use simultaneously. That means you can access the Internet from your iPad or laptop without a router or another peripheral device.

The Layers of a Smartphone

Everyone has a smartphone, or so it seems. In fact, there were an estimated 1.4 billion smartphones in the world as of December 2013 [source: Koetsier]. People are constantly talking on them, taking pictures, surfing the Internet and doing dozens of other things, including shopping for cars. Captain Kirk would be jealous.

At their core, smartphones, and all cell phones for that matter, are mini radios, sending and receiving radio signals. Cell phone networks are divided into specific areas called cells. Each cell has an antenna that receives cell phone signals. The antenna transmits signals just like a radio station, and your phone picks up those signals just as a radio does.


Smartphones use cell phone network technology to send and receive data (think phone calls, Web browsing, file transfers). Developers classify this technology into generations. Do you remember the first generation? It included analog cell phone technology. However, as cell phone technology progressed, the protocols became more advanced. In 2014, cell phones are in the world of the fourth generation, or 4G. Although most carriers are expanding their 4G technology, some companies, such as Samsung, are developing 5G technology, which if recent tests are any indication, will allow you to download an entire movie in less than a second. You can read more about network technologies and protocols in the article How Cell Phones Work.

Smartphone Hardware and Software

As long as we're talking details, let's have a quick look at smartphone hardware.

Some smartphones run on processors. Along with processors, smartphones also have computer chips that provide functionality. Phones with cameras have high-resolution image sensors, just like digital cameras. Other chips support complex functions such as browsing the Internet, sharing multimedia files or playing music without placing too great a demand on the phone’s battery. Some manufacturers develop chips that integrate multiple functions to help reduce the overall cost (fewer chips produced per phone help offset production costs).


You can visualize software for smartphones as a software stack. The stack consists of the following layers:

  • kernel -- management systems for processes and drivers for hardware
  • middleware -- software libraries that enable smartphone applications (such as security, Web browsing and messaging)
  • application execution environment (AEE) -- application programming interfaces, which allow developers to create their own programs
  • user interface framework -- the graphics and layouts seen on the screen
  • application suite -- the basic applications users access regularly such as menu screens, calendars and message inboxes

Smartphone Operating Systems

A man checks out the new Nokia Lumia 1020, which runs Windows Phone 8 and boasts a 41- megapixel camera, during London's Apps World exhibition in October 2013.
A man checks out the new Nokia Lumia 1020, which runs Windows Phone 8 and boasts a 41- megapixel camera, during London's Apps World exhibition in October 2013.
© Piero Cruciatti/Demotix/Corbis

The most important software in any smartphone is its operating system (OS). An operating system manages the hardware and software resources of smartphones. Some platforms cover the entire range of the software stack. Others may only include the lower levels (typically the kernel and middleware layers) and rely on additional software platforms to provide a user interface framework. We've added some snapshots of specific smartphone operating systems.

Designed primarily for touch-screen mobile devices, Android, or Droid, technology is the operating system that most mobile telephones used as of Comscore's February 2014 numbers. Developed by Google, most people consider the Droid technology revolutionary because its open source technology allows people to write program codes and applications for the operating system, which means Android is evolving constantly. Smartphone users can decide whether to download the applications. Moreover, Android operating systems can run multiple applications, allowing users to be multitasking mavens. And get this: Any hardware manufacturer is free to produce its own Android phone by using the operating system. In fact, many smartphone companies do just that. Android app’s store has hundreds of thousands of apps.


Apple is always innovating, and iOS allows iPhone screens to be used simply and logically. Touted by Apple as the “world’s most advance mobile operating system,” iOS supports more access from sports scores to restaurant recommendations. As of publication, its latest version iOS7 allows for automatic updates and a control center that gives users access to their most used features. It also makes surfing the net easier with an overhaul to the Safari browser.

Reviewers say that Windows Phone 8 (WP8) is as simple to use as iOS and as easy to customize as Android. Its crowning achievement is LiveTiles, which are programmed squares that users can rearrange on their screen to easily access the information they want. WP8 works well with other Microsoft products, including Office and Exchange. For those who do a lot of calling, connecting to Facebook and texting, WP8 may meet their needs.

At first glance, experts say, Ubuntu 13.10 Touch might seem like an ordinary operating system, but it’s not. Experts say Ubuntu Touch one of the easiest systems to use, allowing seamless navigation with multiple scopes. There are no hardware buttons on the bottom, for example. Instead, Ubuntu works from the edges. Developed by Canonical, the Ubuntu Touch allows users to unlock the phone from the right edge. You can swipe down from the top edge to access the phone’s indicators, including date, time, messages (from variety of sources, ie: Skype and Facebook) and wireless networks. The phone also makes it easy for people to organize and share photos. Every shot is automatically uploaded to a personal cloud account, which makes it available on all devices, including iOS, Android and Windows [sources: Ubuntu, Vaughan-Nichols].

Flexible Interfaces

Bluetooth can link your phone to lots of different peripherals, including this Beets BLU heart rate monitor.
Bluetooth can link your phone to lots of different peripherals, including this Beets BLU heart rate monitor.
© Frank Duenzl/dpa/Corbis

The core services on smartphones all tie in to the idea of a multipurpose device that can effectively multitask. A user can watch a video, field a phone call, then return to the video after the call, all without closing each application. Or he or she can flip through the digital calendar and to-do list applications without interrupting the voice call. All of the data stored on the phone can be synchronized with outside applications or manipulated by third-party phone applications in numerous ways. Here are a few systems that smartphones support.


This short-range radio service allows phones to wirelessly link up with each other and with other nearby devices that support it. Examples include printers, scanners, input devices, computers and headsets.


Some varieties of Bluetooth only allow communication with one device at a time, but others allow simultaneous connection with multiple devices. To learn more, check out How Bluetooth Works.

Data Synchronization

A phone that keeps track of your personal information, like appointments, to-do lists, addresses, and phone numbers, needs to be able to communicate with all of the other devices you use to keep track of those things. There are hundreds of possible platforms and applications you might use for this in the course of a day. If you want to keep all of this data synchronized with what's on your phone, then you generally have to look for a cell phone that speaks the languages of all of the devices and applications you use. Or you can go out and buy new applications that speak the language of your cell phone.

The Open Mobile Alliance (OMA) is a collaborative organization with the following mission:

Be the center of mobile service enabler specification work, helping the creation of interoperable services across countries, operators and mobile terminals that will meet the needs of the user.

The OMA formed a Data Synchronization Working Group, which continued the work begun by the SyncML Initiative. SyncML was an open-standards project designed to eliminate the trouble of worrying about whether your personal information manager tools sync up with your phone and vice versa. The project is designed so that any kind of data can be synchronized with any application on any piece of hardware, through any network, provided that they are all programmed to OMA standards. This includes synchronization over the Web, Bluetooth, mail protocols and TCP/IP networks.

SyncML allows data to be synchronized from a phone to Windows, Mac and Linux applications using Bluetooth, infrared, HTTP or a USB cable. Visit the OMA Web site for more information.


A smartphone that's compatible with the Java programming language allows the user to load and run Java applications and MIDlets. MIDlets are applications that use a subset of Java and are specifically programmed to run on wireless devices. Java MIDlets include add-ons, games, applications and utilities.

Since there are millions of Java developers worldwide, and the Java development tools are freely accessible, smartphone users can install thousands of third-party applications on their phones. Because of the way the OS architecture of most phones is built, these applications can access and use all of the data on the user's phone.

The Future of Smartphones

With data transmission rates reaching blistering speeds and the incorporation of WiFi technology, the sky is the limit on what smartphones can do. Possibly the most exciting thing about smartphone technology is that the field is still wide open. It's an idea that probably hasn't found its perfect, real-world implementation yet. Every crop of phones brings new designs and new interface ideas. No one developer or manufacturer has come up with the perfect shape, size or input method yet. The next "killer app" smartphone could look like a flip phone, a tablet PC, a candy bar or something no one has conceived of yet.

Perhaps the most challenging consideration for the future is security. Smartphones may be vulnerable to security breaches such as an Evil Twin attack. In one of these attacks, a hacker sets a server’s service identifier to that of a legitimate hotspot or network while simultaneously blocking traffic to the real server. When a user connects with the hacker’s server, information can be intercepted and security is compromised.


On the other side, some critics argue that anti-virus software manufacturers greatly exaggerate the risks, harms and scope of phone viruses in order to help sell their software. Read more in the article How Cell Phone Viruses Work.

The incredible diversity in smartphone hardware, software and network protocols inhibit practical, broad security measures. Most security considerations either focus on particular operating systems or have more to do with user behavior than network security.

For lots more information on smartphones and related topics, check out the links on the following page.

Lots More Information

Related HowStuffWorks Articles

  • "Active objects."
  • Ames, Ben. “Chip Makers Support Mobile TV for Smartphones” IDG News Service. Feb. 12, 2007. ( Jan. 8, 2014) _1.html?source=searchresult
  • ARCchart Whitepaper. “Mobile Operating Systems: The New Generation” September 2006. ( Jan. 8, 2014)
  • comScore. "comScore reports February 2014 U.S. Smartphone Subscriber Market Share." Press release. April 4, 2014. (April 17, 2014)
  • Ecommerce Times. “The March of the Smartphones.”
  • "EDGE Platform." GSM World.
  • "Expo Highlights Healthy Symbian Economy." PDAStreet. Oct. 6, 2004. ( Jan. 8, 2014)
  • "If the mountain will not come to Mahomet, Mahomet must go to the mountain: SyncML plug-in for Microsoft Exchange released."
  • Koetsier, John. “800 million Android smartphones, 300 million iPhones in active use by December 2013, study says.”Feb. 6, 2013. (Jan. 8, 2014)
  • Lavender, Schmidt. "Active Object - An Object Behavioral Pattern for Concurrent Programming."
  • “Mobile phones to get more touchy, report finds.” Feb. 22, 2007. ( Jan. 8, 2014)
  • “Linux, Windows forecast to pass Symbian by 2010.” Feb. 9, 2006 (Jan. 9, 2013)
  • OMA Technical Section - SyncML Whitepaper. (Jan. 8, 2014)
  • OMA Technical Section - Affiliates - SyncML Compliant Products. (Jan. 9, 2014)
  • Palm Infocenter. (Jan. 8, 2014)
  • Prince, Brian. “Next Wave in Security: Protecting Smart Phones, PDAs.” eWeek. Feb. 9, 2007. (Jan. 9, 2014)
  • Rash, Wayne. “Big Changes Ahead for Smart Phone Market.” Nov. 30, 2006. ( Jan. 8, 2014),1895,2065929,00.asp
  • Rouse, Margaret. “Mobile Telephony Fast Reference Guide.” December 2010. (Jan. 8, 2014),289893,sid9_gci1192492,00.html
  • Series 60 Application Development. (Jan. 8, 2014)
  • Series 60 Platform. (Jan. 8, 2014)
  • Smartphone Thoughts. (Jan. 8, 2014),8313
  • Symbian: Technology. (Jan. 8, 2014)
  • Whitepapers. (Jan. 8, 2014)
  • White, Dave. “Mobile Control of Your Front Door”. Mobile Magazine. Feb. 21, 2007. ( Jan. 8, 2014)