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Etherstack
''Etherstack'' is a provider of wireless communications software for the Professional/Land Mobile Radio and defense industries in Europe, Asia, and North America. Their products encompass wireless protocol stacks, IP-based communication networks, cryptographic communications, Software Defined Radio (SDR), and Software Communications Architecture (SCA) compatible waveforms. Etherstack develops and licences wireless technology to third party vendors in Europe, the United States, Canada, Japan, Korea, Australia and New Zealand. It is a licensor of standards-based APCO P25, DMR, TETRA and NATO technology for emergency and defence communications. Etherstack’s subsidiary Auria Wireless uses Etherstack technology to deliver fixed and deployable secure, standards-based mission critical communications systems via VHF, UHF, LTE, and satellite. Etherstack’s technology includes waveform software and modules (MANET / BLOS / LOS / P25 / sovereign), SDR and radio transceiver hardware, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Company
A public company is a company whose ownership is organized via shares of stock which are intended to be freely traded on a stock exchange or in over-the-counter markets. A public (publicly traded) company can be listed on a stock exchange (listed company), which facilitates the trade of shares, or not (unlisted public company). In some jurisdictions, public companies over a certain size must be listed on an exchange. In most cases, public companies are ''private'' enterprises in the ''private'' sector, and "public" emphasizes their reporting and trading on the public markets. Public companies are formed within the legal systems of particular states, and therefore have associations and formal designations which are distinct and separate in the polity in which they reside. In the United States, for example, a public company is usually a type of corporation (though a corporation need not be a public company), in the United Kingdom it is usually a public limited company (plc), i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project 25
Project 25 (P25 or APCO-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 (typically FM) 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 repeaters and handheld walkie-talkie use. Starting around 2012, products became available with the newer phase 2 modulation protocol, the older protocol known as P25 became P25 phase 1. P25 phase 2 products use the more advanced AMBE2+ vocoder, which allows audio to pass through a more compressed bitstream and provides two TDMA voice ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Mobile Radio
Digital mobile radio (DMR) is a specification for commercial products so they can interoperate. It is defined by a standard created by the European Telecommunications Standards Institute (ETSI), and is designed to be low-cost and easy to use. DMR, along with P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary AMBE+2 vocoder. DMR and P25 II both use two-slot TDMA in a 12.5 kHz channel, while NXDN uses discrete 6.25 kHz channels using frequency division and TETRA uses a four-slot TDMA in a 25 kHz channel. DMR was designed with three tiers. DMR tiers I and II (conventional) were first published in 2005, and DMR III (Trunked version) was published in 2012, with manufacturers producing products within a few years of each publication. The primary goal of the standard is to specify a digital system with low complexity, low cost and interoperability across brands, so radio communications purchasers a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPT-1327
MPT 1327 is an industry standard for trunked radio communications networks. First published in January 1988 by the British Radiocommunications Agency, and is primarily used in the United Kingdom, Europe, South Africa, New Zealand, Australia and even China. Many countries had their own version of numbering/user interface, including MPT1343 in the UK, Chekker (Regionet 43) in Germany, 3RP (CNET2424) in France, Multiax in Australia, and Gong An in China. MPT systems are still being built in many areas of the world, due to their cost-effectiveness. Digital alternatives The TETRA trunked radio standard was developed by the European Telecommunications Standards Institute (ETSI), as a digital alternative to analogue trunked systems. However, TETRA, with its enhanced encryption capability, has developed into a higher tier (public safety) product, currently mainly used by governments, some larger airports and government-owned utilities. DMR (digital mobile radio), and dPMR ( d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raytheon
Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitalization. In addition, it is one of the largest providers of intelligence services. Raytheon Technologies manufactures aircraft engines, avionics, aerostructures, cybersecurity, guided missiles, air defense systems, satellites, and drones. The company is also a large military contractor, getting a significant portion of its revenue from the U.S. government. The company is the result of the merger of equals between the aerospace subsidiaries of United Technologies Corporation (UTC) and the Raytheon Company, which was completed on April 3, 2020. Before the merger, UTC spun off its non-aerospace subsidiaries Otis Elevator Company and Carrier Corporation. UTC is the nominal survivor of the merger but it changed its name to Raytheon Technologies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defence Science And Technology Laboratory
The Defence Science and Technology Laboratory (Dstl) is an executive agency of the Ministry of Defence (United Kingdom), Ministry of Defence of the United Kingdom. Its stated purpose is "to maximise the impact of science and technology for the defence and security of the UK". The agency is headed by Paul Hollinshead as its Chief Executive, with the board being chaired by Adrian Belton. Ministerial responsibility lies with the Minister for Defence Procurement. History Dstl was formed from the July 2001 split of the Defence Evaluation and Research Agency (DERA). Dstl was established to carry out and retain the science and technology work that is best done within government, while work that could be done by industry (forming the majority of DERA's activities) was transferred to Qinetiq, a government-owned company that was later floated on the stock exchange. Dstl absorbed the Home Office's Centre for Applied Science and Technology (CAST) in April 2018, taking on CAST's role to app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swedish Defence Material Administration
The Swedish Defence Materiel Administration ( sv, Försvarets materielverk, FMV) is a Swedish government agency that reports to the Ministry of Defence. The agency is responsible for the supply of materiel to the Swedish defence organisation. It is located in Stockholm. Director Generals since 1968 *1968–1975: Sten Wåhlin *1974–1982: Ove Ljung *1982–1988: Carl-Olof Ternryd *1988–1995: Per Borg *1995–2005: Birgitta Böhlin *2005–2012: Gunnar Holmgren *2012–2015: Lena Erixon *2015–2016: Dan Ohlsson (acting) *2016–present: Göran Mårtensson See also *Government agencies in Sweden The government agencies in Sweden are state-controlled organizations that act independently to carry out the policies of the Government of Sweden. The ministries are relatively small and merely policy-making organizations, allowed to monitor the ... References External links * 1968 establishments in Sweden Defence agencies of Sweden Government agencies established in 1968 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icom Incorporated
is a Japanese manufacturer of radio transmitting and receiving equipment, founded in 1954 by Tokuzo Inoue with the company's original name being "Inoue". Its products now include equipment for radio amateurs, pilots, maritime applications, land mobile professional applications and radio scanner enthusiasts. Its headquarters are in Osaka, Japan, with branch offices in the United States (in Kirkland, Washington), Canada (in Delta, British Columbia), Australia (Melbourne, Victoria), New Zealand (Auckland), the United Kingdom (Kent, England), France (Toulouse), Germany (Bad Soden), Spain (Barcelona) and the People's Republic of China (Beijing). Protocols IDAS IDAS is Icom's implementation of the NXDN protocol for two-way digital radio products intended for commercial Private Land Mobile Radio (PLMR) and low-end public safety communications systems. NXDN is a Common Air Interface (CAI) technical standard for mobile communications. It was developed jointly by Icom and Kenwood Corpor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P25 ISSI
{{no footnotes, date=March 2015 The Project 25 Inter RF Subsystem Interface ( P25 ISSI) is a non-proprietary interface that enables RF subsystems (RFSSs) built by different manufacturers to be connected together into wide area networks so that users on different networks can talk with each other. The wide area network connections using the ISSI provide an extended coverage area for subscriber units (SUs) that are roaming. The extended coverage area is important for public safety first responders that provide assistance in other jurisdictions during an emergency. The ISSI supports the messaging, and procedures necessary to enable RFSSs to track and locate SUs, set up and teardown calls and transfer voice information to the SUs. The ISSI uses SIP and RTP protocols (standardized protocols) to provide the messaging between RFSSs. The modern Land Mobile Radio (LMR) system includes many features in addition to voice communication. Many features will not work across systems connecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line-of-sight Propagation
Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves travel in a direct path from the source to the receiver. Electromagnetic transmission includes light emissions traveling in a straight line. The rays or waves may be diffracted, refracted, reflected, or absorbed by the atmosphere and obstructions with material and generally cannot travel over the horizon or behind obstacles. In contrast to line-of-sight propagation, at low frequency (below approximately 3 MHz) due to diffraction, radio waves can travel as ground waves, which follow the contour of the Earth. This enables AM radio stations to transmit beyond the horizon. Additionally, frequencies in the shortwave bands between approximately 1 and 30 MHz, can be refracted back to Earth by the ionosphere, called skywave or "skip" propagation, thus giving radio transmissions in this range a potentially global reach. However, at frequencies above ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BLOS
Non-line-of-sight (NLOS) radio propagation occurs outside of the typical Line-of-sight propagation, line-of-sight (LOS) between the transmitter and receiver, such as in ground reflections. Near-line-of-sight (also NLOS) conditions refer to partial obstruction by a physical object present in the innermost Fresnel zone. Obstacles that commonly cause NLOS propagation include buildings, trees, hills, mountains, and, in some cases, high voltage electric power lines. Some of these obstructions reflect certain radio frequencies, while some simply absorb or garble the signals; but, in either case, they limit the use of many types of radio transmissions, especially when low on power budget. Lower power levels at a receiver reduce the chance of successfully receiving a transmission. Low levels can be caused by at least three basic reasons: low transmit level, for example Wi-Fi power levels; far-away transmitter, such as 3G more than away or Television station#Transmission, TV more than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MANET
A wireless ad hoc network (WANET) or mobile ad hoc network (MANET) is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers in wired networks or access points in wireless networks. Instead, each node participates in routing by forwarding data for other nodes, so the determination of which nodes forward data is made dynamically on the basis of network connectivity and the routing algorithm in use. In the Windows operating system, ad hoc is a communication mode (setting) that allows computers to directly communicate with each other without a router. Wireless mobile ad hoc networks are self-configuring, dynamic networks in which nodes are free to move. Such wireless networks lack the complexities of infrastructure setup and administration, enabling devices to create and join networks "on the fly". Each device in a MANET is free to move independently in any direction, and will therefore change it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
