Primarily used to describe handheld communications technologies allowing two-way interpersonal communications, may increasingly include a variety of wearable devices and unmanned aerial vehicles (UAVs). Basically, if it can move or be moved from a stationary position, and it permits communications on at least an interpersonal or Machine to Machine (M2M) telephonic or messaging level, it is a mobile communications device.

Mobile communications history began with the onset of radio communications over 100 years ago, and continues today with wearable communications and M2M devices. Mobile devices, increasingly in developed countries and often exclusively in developing countries, have become the preferred method for reaching out to other individuals and communications systems like the Internet.

Radio communications allowed telegraph messages to traverse the United States and the Atlantic Ocean in the early 1900s, and were used most famously to report the sinking of the Titanic in 1912. Besides ship-to-ship and ship-to-shore communications, other early uses of mobile radio were primarily for military communications during World Wars I and II. Domestically, police departments began to use mobile radios and car radios to communicate about pending criminal activity on a live, real-time basis. Still, commercial use of mobile technologies was limited to certain small segments of the population such as Citizens Band (CB) radio aficionados and people who used radio communications for their occupations such as soldiers, police officers, and emergency professionals.

As radio communications proliferated, the need for more bands and more available spectrum, as regulated by the Federal Communications Commission (FCC), became the primary concern for companies offering mobile communications and/or selling mobile devices to customers. In the beginning, the FCC allowed two competing mobile service providers in each geographic area to avoid competing calls on the same portion of spectrum but still to allow some competition to drive down prices and encourage diversity in the features. This carefully constructed balance between pure economic efficiency and public policy continues to drive regulatory decisions today, including spectrum auctions and decisions to approve new services.

Carriers began to build networks of cell phone towers across the United States to complement and connect with the underground and aboveground telephone wire networks used to provide plain old telephone service (POTS) to customers. For most of the twentieth century, mobile service was viewed as an add-on, even a luxury service, for customers who intended to keep their telephone landlines in service. The first consumer uses of mobile phone devices were often referred to as car phones and were used solely in motor vehicles.

After telegraph messages, voice transmissions through one-way radio, two-way radio, and telephonic communications were the primary application (app) for mobile devices. Text communications began in a nascent form in the early 1990s and began to use more and more mobile device capacity over voice in the following years. Text communications, or Short Message Service (SMS), allows a user to type a brief message of fewer than 160 alphanumeric characters on a device and have it appear on another mobile device or computer. Early text messages were contained in one-way pagers used to alert emergency room doctors on call and other personnel in the field. Nokia was one of the first companies to manufacture mobile devices that had this capacity. In 1997, Nokia produced a mobile device with a full keyboard, easing the ability to text with speed and accuracy. Early texting systems were self-contained. By about 2000, however, interoperability between texting systems allowed the function to become more popular and useful on mobile devices. Mobile devices still use the QWERTY keyboard that typists are familiar with from using typewriters and then computer keyboards. Texting in short messages has changed communications patterns and language customs, especially for the younger generation who grew up using text messages to communicate with friends. Abbreviations and emojis (iconic symbols indicating objects and/or emotional content) have become a new language of communication, parallel to and often supplanting Standard English usage.

Early mobile devices used analog technology, which was later replaced by digital, packet-switched technology. Cellular phones allowed spectrum to be divided into smaller and smaller areas to reduce interference from other spectrum uses, but analog phone calls were notoriously difficult to hear. The primary difference from a user perspective was that analog calls often searched for available frequencies and users would hear static on the line. Digital technology eliminated static, but early digital calls often lost some sounds due to skipped packets of data or calls were dropped entirely when the signal was lost. Digital technology enabled the next generation of mobile devices, which included not only telephonic communications but also access to data-driven services like the Internet. The costly changeover to an entirely different model of transmitting information via mobile devices would eventually make mobile communications less expensive and more expansive. Multiple technical standards still exist internationally, including Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA) in the United States, and Global System for Mobile Communications/Groupe Spécial Mobile (GSM) in Europe. Some mobile devices can operate on more than one system, which allows the user to take the device abroad and still use it, although the user will need to engage service in the alternative country, either by subscription or by roaming, a service that allows individual calls, texts, or data usage but charges the user a higher per-use rate.

Apple brought the iPhone to the mobile device market in 2007. The iPhone was unique in the mobile device market because of its Apple-controlled app market and its integrated touchscreen keypad. The touchscreen is now a given in the smartphone market, as is some of the user customization features like the orientation of the screen, choice of applications, and autocorrected text input. When Internet usage became available on mobile devices called smartphones, telephone and text usage was often metered, with a pay-by-the-minute plan or capped, while data was unlimited. Now, carriers offer the lesser-used phone capabilities of smartphones on an unlimited basis and meter and cap the bandwidth-demanding data services for these devices. Recently, some customers have opted to become mobile-only customers and have requested disconnection of their landline phones. This is not a perfect alternative for location services that are based on a home address such as E911, and mobile communications based on aboveground towers and limited battery life are more vulnerable to a natural disaster.

The definition of mobile devices has expanded to include objects that were manufactured previously without any thought to online or communications capabilities. Vehicles have begun to communicate with one another and with networks to transmit location, intention, and emergency alerts, bringing new meaning to the antiquated term car phone. The Internet of things (IoT) includes mobile devices capable of communicating with the Internet, including formerly unconnected home appliances, UAVs, wearable devices, and nearly any mobile device with a microchip embedded in it. It can be argued that biological and organic matter have become part of the IoT when pets contain microchips (radio-frequency ID [RFID]), and fingerprints are used to identify individuals for password access to mobile devices.

Mobile devices are used simultaneously with other mobile and stationary communications and entertainment portals. Computer tablet devices such as Apple's iPad, laptop computers, smartphones, and other interactive devices may be used by one individual at the same time, with the user switching her or his attention from one screen to another to watch, download, comment, or communicate with other individuals.

Given the popularity and ubiquity of mobile devices, the amount of data collected by the devices is prodigious. To compound the problem, the data are often personal information connected to the individual user, and, especially in the case of largely unregulated IoT devices, are often not encrypted to enhance user privacy. This information can be resold to advertisers and marketers intent on using the data to sell products and services to the mobile device user. The data may also be used by law enforcement and other government entities to track individuals to monitor terrorists and other individuals. Even when data is created by or collected from a specific user, it is often legally unclear who owns this data and therefore anyone may access, correct, store, or sell it. In many cases, a consumer uses the mobile device, the app on the mobile device, or another related service for free or at low cost and may not realize that his or her data may be sold to support the free product.

Federal and state laws regulate certain uses of mobile devices, but not all uses and users are subject to these regulations. The Children's Online Privacy Protection Act of 2013 (COPPA) protects only children under age thirteen, and the Health Insurance Portability and Accountability Act of 1996 (HIPAA) protects medical and healthcare information but only when such information is kept by a covered entity such as a doctor, insurance company, or hospital. For example, if a doctor prescribes an insulin pump that transmits data about insulin levels to the doctor, the data collected on the mobile device would be regulated by HIPAA. If a consumer buys a fitness monitor online or from a retail establishment and uses it to collect and upload to the Internet various weight, age, gender, global positioning system (GPS) location, and fitness data, the collection and use of that data is far less likely to be regulated or even monitored by any government entity. The Gramm-Leach-Bliley Act (GLBA), the Securities and Exchange Commission (SEC) regulations, and a host of other financial regulations cover the exchange of financial data through mobile devices, including banking transactions, credit card, and mobile app payment systems. In each case, there is still data that may not be encrypted end to end (from the beginning of the transaction until its conclusion). The data then remain accessible on the device and possibly via remote access as well.

Riley v. California, 573 U.S. ___ (2014), a U.S. Supreme Court case, illustrated the legal implications of carrying an extensive database containing all of the user's personal information in a pocket. The police pulled Riley's vehicle over when they noticed his expired vehicle identification license tags, and they conducted a search. Riley also had his cell phone in his pocket; the officers searched the phone and found photos suggesting that Riley belonged to a relevant gang that was suspected in a shooting. Riley was accused of a shooting that occurred out of a motor vehicle. Under the Fourth Amendment to the U.S. Constitution, citizens are protected from unreasonable searches and seizures of their property. The Supreme Court, in the Riley case, found that there was no emergency and the data that the phone contained could wait until a legal warrant was obtained to search the mobile device, similar to a warrant required to search a device located in a person's home. This case may be distinguished from other cases if mobile devices are found to contain weapons or other immediately dangerous objects.

Issues of legal notice and consent for privacy purposes and, more generally, the effective communication of privacy policies, vary extensively by size and type of mobile device. The largest devices have sufficient screens to convey an entire privacy policy document and allow consent via a click-through agreement. Companies can provide thorough privacy policies in this situation, and the policies address all of the potential methods of collecting personal data and all of the foreseeable uses of the data. Smaller devices may have tiny screens that do not lend themselves to reviewing an entire contract or multipage privacy policy. This makes it difficult to obtain consent, either overall for the use of the device or on a use-by-use basis. Some devices, particularly IoT devices and very mobile devices such as UAVs, either do not have screens at all or the screens are not readily available to all affected by the use of such devices. Consumers would not be able to opt in or opt out on a per-use basis without constant access to the screen of the mobile device. Solutions for delivering adequate notice and obtaining valid consent from users are limited in these examples, and may have to come from public awareness campaigns directed to all potential users, which, in the case of UAV and drone mobile device use, may be anyone in the vicinity.

To protect individual privacy on mobile devices, users may begin by reading privacy policies, conducting online research, and looking for third-party trustmarks and/or seals to compare different sites and apps to choose the most privacy-protective service that meets their needs. Next, users can look for privacy options available within each game, social media app, or service on the device to secure their personal data. For example, social media settings often offer users the ability to post selectively to a certain group of recipients, set on a default basis or on a per-use basis. Particularly for young users of social media, those beyond the protection of COPPA but still under the age of majority, these settings should be set to protect the most personal data possible. Beyond individual actions, separate services and privacy-protective apps may be developed to protect privacy across multiple platforms. Trade associations for mobile device manufacturers, mobile communications service providers, mobile app designers, and mobile advertisers each and collectively may design industry standards for the ethical treatment of privacy information collected from mobile users, above and beyond any of the legal requirements imposed on these groups. Any comprehensive federal legislation on data privacy should acknowledge the vulnerability of mobile devices to privacy violations and data breaches.

Security of mobile devices also presents several legal, technical, and ethical concerns. Physical security requires that devices be held by individuals and not shared, lost, or stolen. Mobile devices are especially likely to be shared, lost, and/or stolen and therefore should be protected by encryption and password lockout screens if they are not in use for a set period. Data security issues include the ability to hack the devices and to hack into the apps and services available on the mobile devices. Network security should ensure that the network that connects mobile devices also be prepared for the onslaught of data and people looking to access and use that data, whether for paid advertising purposes or illegal use. Bring your own device (BYOD) means that consumers are bringing their personal devices into the workplace, complicating secure systems designed by engineers for an individual company's needs. Product designers for mobile devices must consider not only the parameters of the physical device and its preloaded software but also the myriad context(s) in which mobile devices may be used. Mobile device designers should incorporate the possibility of software upgrades and patches, and additional uses in the future, even as the generations of devices become shorter and shorter and new devices replace old devices more and more quickly.

Further Reading

See also: Apps; Federal Communications Commission (FCC); Federal Trade Commission (FTC); Telephones