Wireless communication, or sometimes simply wireless, is the transfer of information or power between two or more points that are not connected by an electrical conductor.
The most common wireless technologies use radio waves. With radio waves distances can be short, such as a few meters for Bluetooth or as far as millions of kilometers for deep-space radio communications.
It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking.
Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mice, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones.
Somewhat less common methods of achieving wireless communications include the use of other electromagnetic wireless technologies, such as light, magnetic, or electric fields or the use of sound.
The term wireless has been used twice in communications history, with slightly different meaning. It was initially used from about 1890 for the first radio transmitting and receiving technology, as in wireless telegraphy, until the new word radio replaced it around 1920.
The term was revived in the 1980s and 1990s mainly to distinguish digital devices that communicate without wires, such as the examples listed in the previous paragraph, from those that require wires or cables.
This became its primary usage in the 2000s, due to the advent of technologies such as mobile broadband, Wi-Fi and Bluetooth.
Wireless operations permit services, such as long-range communications, that are impossible or impractical to implement with the use of wires.
The term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g. radio transmitters and receivers, remote controls, etc.) which use some form of energy (e.g. radio waves, acoustic energy,)
to transfer information without the use of wires.
Information is transferred in this manner over both short and long distances. The world’s first wireless telephone conversation occurred in 1880, when Alexander Graham Bell and Charles Sumner Tainter invented and patented the photophone, a telephone that conducted audio conversations wirelessly over modulated light beams.
The photophone existed several decades before its practical applications in military communication and later in fiber-optic communications.
A number of wireless electrical signaling schemes including sending electric currents through water and the ground using electrostatic and electromagnetic induction were investigated for telegraphy in the late 19th century before practical radio systems became available. These includes:
- A patented induction system by Thomas Edison allowing a telegraph on a running train to connect with telegraph wires running parallel to the tracks.
- William Preece induction telegraph system for sending messages across bodies of water.
In 1894, Guglielmo Marconi began developing a wireless telegraph system using radio waves, which had been known about since proof of their existence in 1888 by Heinrich Hertz, but discounted as communication format since they seemed, at the time, to be a short range phenomenon.
Marconi soon developed a system that was transmitting signals way beyond distances anyone could have predicted. Guglielmo Marconi and Karl Ferdinand Braun were awarded the 1909 Nobel Prize for Physics for their contribution to this form of wireless telegraphy.
Free-space optical communication (FSO) is an optical communication technology that uses light propagating in free space to transmit wirelessly data for telecommunications or computer networking. “Free space” means the light beams travel through the open air or outer space.
Wireless data communications allows wireless transfer of data or information between desktop computers, laptops, tablet computers, cell phones and other related devices. The various available technologies differ in local availability, coverage range and performance, and in some circumstances users employ multiple connection types and switch between them using connection manager software or a mobile VPN to handle the multiple connections as a secure, single virtual network.
Wi-Fi is a wireless local area network that enables portable computing devices to connect easily with other devices, peripheries, and the Internet. Standardized as IEEE 802.11 a, b, g, n, ac, ax, Wi-Fi has link speeds similar to older standards of wired Ethernet.
Wi-Fi has become the de facto standard for access in private homes, within offices, and at public hotspots. Some businesses charge customers a monthly fee for service, while others have begun offering it free in an effort to increase the sales of their goods.
Cellular data service offers coverage within a range of 10-15 miles from the nearest cell site. Speeds have increased as technologies have evolved, from earlier technologies such as GSM, CDMA and GPRS, through 3G, 3.5G, 3.75G to 4G networks such as W-CDMA, EDGE or CDMA2000. As of 2018, the proposed next generation is 5G.
Mobile-satellite communications may be used where other wireless connections are unavailable, such as in largely rural areas or remote locations. Satellite communications are especially important for transportation, aviation, maritime and military use.
Wireless sensor networks are responsible for sensing noise, interference, and activity in data collection networks.
This allows us to detect relevant quantities, monitor and collect data, formulate clear user displays, and to perform decision-making functions Wireless data communications are used to span a distance beyond the capabilities of typical cabling in point-to-point communication and point-to-multipoint communication, to provide a backup communications link in case of normal network failure, to link portable or temporary workstations, to overcome situations where normal cabling is difficult or financially impractical, or to remotely connect mobile users or networks.
Medical Wi-Fi Technologies
New wireless technologies, such as mobile body area networks (MBAN), have the capability to monitor blood pressure, heart rate, oxygen level and body temperature. The MBAN works by sending low powered wireless signals to receivers that feed into nursing stations or monitoring sites. This technology helps with the intentional and unintentional risk of infection or disconnection that arise from wired connections.
How Wi-Fi has Become Mission Critical
Business networks today have evolved to support people who are on the move. Employees and employers, students and faculty, government agents and those they serve, sports fans and shoppers, all are mobile and many of them are “connected”.
This was the vision of mobility-all environment, and a reality today where people are demanding connectivity anytime and anywhere.
The first enterprise Wi-Fi networks were an added convenience used for web surfing in enterprise lobbies or conference rooms. For these applications, a best-effort level of performance was acceptable.
Now Wi-Fi has matured to the point that it is being deployed for many mission-critical applications. Hospitals use Wi-Fi for mobile access to patient files and to remotely monitor secondary bedside systems. In retail and manufacturing, Wi-Fi is used for logistics and business transactions. Samll branch offices are beginning to use Wi-Fi as the exclusive network access method, forgoing wired connections.
And increasingly, Wi-Fi is being used for voice and video, which is sensitive to the impart of interference.
In all these examples, Wi-Fi networks are expected to run with very high reliability. It’s no longer acceptable for Wi-Fi networks to have unexpected downtime due to interference.