A wireless network is a computer network that uses wireless data connections between network nodes.
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter. Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF or lower bands. UHF radio waves propagate mainly by line of sight; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, and numerous other applications.
Wireless communication is the transfer of information between two or more points that do not use an electrical conductor as a medium by which to perform the transfer. The most common wireless technologies use radio waves. With radio waves, intended 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 mouse, 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.
Terrestrial Trunked Radio, a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by government agencies, emergency services, for public safety networks, rail transport staff for train radios, transport services and the military. TETRA is the European version of trunked radio, similar to Project 25.
Base station is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service."
Professional mobile radio are person-to-person two-way radio voice communications systems which use portable, mobile, base station, and dispatch console radios. PMR radio systems are based on such standards as MPT-1327, TETRA, APCO 25, and DMR which are designed for dedicated use by specific organizations, or standards such as NXDN intended for general commercial use. These systems are used by police, fire, ambulance, and emergency services, and by commercial firms such as taxis and delivery services. Most systems are half-duplex, in which multiple radios share a common radio channel, and only one can transmit at a time. Transceivers are normally in receive mode, the user presses a push-to-talk button on his microphone when he wants to talk, which turns on his transmitter and turns off his receiver. They use channels in the VHF and UHF bands, giving them a limited range, usually 3 to 20 miles depending on terrain. Output power is typically limited to 4 watts. Repeaters installed on tall buildings, hills or mountain peaks are used to increase the range of systems.
A two-way radio is a radio that can both transmit and receive radio waves, unlike a broadcast receiver which only receives content. It is an audio (sound) transceiver, a transmitter and receiver in one unit, used for bidirectional person-to-person voice communication with other users with similar radios. Two-way radios are available in stationary, mobile, and hand-held portable models. Hand-held two-way radios are often called walkie-talkies, handie-talkies or hand-helds. Two-way radios are used by groups of geographically separated people who need to keep in continuous voice communication, such as aircraft pilots and air traffic controllers, ship captains and harbormasters, emergency services personnel like firemen, policemen, and ambulance paramedics, taxi and delivery services, soldiers and military units, fast food and warehouse employees, and radio amateurs.
Sepura Limited is a British telecommunications equipment provider that designs, manufactures and supplies digital mobile radio products, systems and applications for business and critical communications. The company specialises in Terrestrial Trunked Radio (TETRA) technology.
Project 25 is a suite of standards for interoperable digital two-way radio products. P25 was developed by public safety professionals in North America and has gained acceptance for public safety, security, public service, and commercial applications worldwide. P25 radios are a direct replacement for analog UHF radios, but add the ability to transfer data as well as voice, allowing for more natural implementations of encryption and text messaging. P25 radios are commonly implemented by dispatch organizations, such as police, fire, ambulance and emergency rescue service, using vehicle-mounted radios combined with handheld walkie-talkie use.
The history of mobile phones covers mobile communication devices that connect wirelessly to the public switched telephone network.
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time talking. These systems typically have access to multiple channels, up to 40-60, so multiple groups in the same area can communicate simultaneously. In a conventional (non-trunked) system, channel selection is done manually; before use the group must decide which channel to use, and manually switch all the radios to that channel. This is an inefficient use of scarce radio channel resources because the user group must have exclusive use of their channel regardless of how much or how little they are transmitting. There is also nothing to prevent multiple groups in the same area from choosing the same channel, causing conflicts and 'cross-talk'. A trunked radio system is an advanced alternative in which the channel selection process is done automatically by a central controller (computer).
TETRAPOL is a digital professional mobile radio standard, as defined by the Tetrapol Publicly Available Specification (PAS), in use by professional user groups, such as public safety, military, industry and transportation organizations throughout the world. Airbus Defence and Space is the main supplier of this technology.
Airwave Solutions Ltd. is a British mobile communication company that operates the Airwave network, a mobile communications network used by Great Britain's emergency services. The Airwave network is based on the specialist Terrestrial Trunked Radio (TETRA) specification. Airwave was acquired by Motorola Solutions in February 2016 and now operates as a wholly owned subsidiary.
MPT 1327 is an industry standard for trunked radio communications networks.
ASTRO 25 is the next generation of ASTRO digital two-way radio communications by Motorola Solutions. Motorola first introduced digital two-way radio in the U.S. in 1991 under the name ASTRO Digital Solutions.
Police radio is a communications radio system used by law enforcement agencies all over the world.
Jesse Eugene Russell is an American inventor. He was trained as an electrical engineer at Tennessee State University and Stanford University, and worked in the field of wireless communication for over 20 years. He holds patents and continues to invent and innovate in the emerging area of next generation broadband wireless networks, technologies and services, often referred to as 4G. Russell was inducted into the US National Academy of Engineering for his contributions to the field of wireless communication. He pioneered the field of digital cellular communication in the 1980s through the use of high power linear amplification and low bit rate voice encoding technologies and received a patent in 1992 for his work in the area of digital cellular base station design.
Etherstack is a provider of wireless communications software to the Professional/Land Mobile Radio and defence industries in Europe, Asia and North America. Their products cover wireless protocol stacks, IP-based communication networks, cryptographic communication solutions, Software Defined Radio (SDR) and Software Communications Architecture (SCA) compatible waveforms. Etherstack provides these software technologies to defence organisations and commercial manufacturers, such as Icom, Inc.; the Swedish Defence Material Administration; and Raytheon JPS.
Mobile technology is the technology used for cellular communication. Mobile technology has evolved rapidly over the past few years. Since the start of this millennium, a standard mobile device has gone from being no more than a simple two-way pager to being a mobile phone, GPS navigation device, an embedded web browser and instant messaging client, and a handheld gaming console. Many experts believe that the future of computer technology rests in mobile computing with wireless networking. Mobile computing by way of tablet computers is becoming more popular. Tablets are available on the 3G and 4G networks. Mobile technology has different meanings in different aspects, mainly mobile technology in information technology and mobile technology in basketball technology, mainly based on the wireless technology of wireless devices equipment information technology integration.
Hytera is a Chinese manufacturer of radio transceivers and radio systems. The enterprise was founded in Shenzhen, Guangdong, in 1993 and operates on a global basis. Radio systems and radio solutions in compliance with the DMR, TETRA, LTE and MPT-1327 standard as well as corresponding radio transceivers range among the products of Hytera. Hytera is major contributor to the PDT Standard, which is designed for public safety organizations in China. The company is a major supplier to China's Ministry of Public Security. Hytera ranks as the second largest global radio terminal manufacturer with a market share of 12.6%. The company is the defendant, as well as the plaintiff, in ongoing intellectual property litigation with Motorola Solutions. Hytera is also a plaintiff of an antitrust lawsuit against Motorola Solutions.
