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WLAN Channels
Wireless LAN (WLAN) channels are frequently accessed using IEEE 802.11 protocols. The 802.11 standard provides several radio frequency bands for use in Wi-Fi communications, each divided into a multitude of channels numbered at 5 MHz spacing (except in the 45/60 GHz band, where they are 0.54/1.08/2.16 GHz apart) between the centre frequency of the channel. The standards allow for channels to be bonded together into wider channels for faster throughput. 860/900 MHz (802.11ah) 802.11ah operates in sub-gigahertz unlicensed bands. Each world region supports different sub-bands, and the channels number depends on the starting frequency on the sub-band it belongs to. Therefore there is no global channels numbering plan, and the channels numbers are incompatible between world regions (and even between sub-bands of a same world region). The following sub-bands are defined in the 802.11ah specifications: 2.4 GHz (802.11b/g/n/ax/be) 14 channels are designated in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LANs), personal area networks (PANs), and metropolitan area networks (MANs). The IEEE 802 LAN/MAN Standards Committee (LMSC) maintains these standards. The IEEE 802 family of standards has had twenty-four members, numbered 802.1 through 802.24, with a working group of the LMSC devoted to each. However, not all of these working groups are currently active. The IEEE 802 standards are restricted to computer networks carrying variable-size packets, unlike cell relay networks, for example, in which data is transmitted in short, uniformly sized units called cells. Isochronous signal networks, in which data is transmitted as a steady stream of octet (computing), octets, or groups of octets, at regular time intervals, are also outside the scope of the IEEE 802 standards. The number 802 has no significance: it was simply the next number in the sequence that the IEEE used fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short-range Device
A short-range device (SRD), described by ECC Recommendation 70-03, is a radio-frequency transmitter device used in telecommunication that has little capability of causing harmful interference to other radio equipment. Short-range devices are low-power transmitters, typically limited to 25–100 mW effective radiated power (ERP) or less, depending on the frequency band, which limits their useful range to a few hundred meters, which do not require licenses to use. Short-range wireless technologies include Bluetooth, Wi-Fi, NearLink, near-field communication (NFC), LPWAN, ultra-wideband (UWB) and IEEE 802.15.4. They are implemented by chips fabricated as RF CMOS integrated circuit (RF circuit). , short-range wireless chips ship approximately billion units annually, with Bluetooth accounting for over 55% of shipments and Wi-Fi around 35% of shipments. Applications for short-range wireless devices include power meters and other remote instrumentation, RFID applications, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular V2X
Cellular V2X (C-V2X) is an umbrella term that comprises all 3rd Generation Partnership Project (3GPP) V2X technologies for connected mobility and self-driving cars. It includes both direct and cellular network communications and is an alternative to 802.11p, the IEEE specified standard for V2V and other forms of V2X communications. Cellular V2X uses 3GPP standardised 4G LTE or 5G mobile cellular connectivity to exchange messages between vehicles, pedestrians, and wayside traffic control devices such as traffic signals. It commonly uses the 5.9 GHz frequency band, which is the officially designated intelligent transportation system (ITS) frequency in most countries. C-V2X can function without network assistance and exceeds the range of DSRC by about 25%. C-V2X was developed within the 3GPP to replace DSRC in the US and C-ITS in Europe. History In 2014, 3GPP Release 13 spurred studies to test the applicability of the then current standards to V2X. This resulted in the 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dedicated Short-range Communications
Dedicated short-range communications (DSRC) is a technology for direct wireless exchange of vehicle-to-everything (V2X) and other intelligent transportation systems (ITS) data between vehicles, other road users (pedestrians, cyclists, etc.), and roadside infrastructure (traffic signals, electronic message signs, etc.). DSRC, which can be used for both one- and two-way data exchanges, uses channels in the licensed 5.9 GHz band. DSRC is based on IEEE 802.11p. History In October 1999, the United States Federal Communications Commission (FCC) allocated 75 MHz of spectrum in the 5.9 GHz band for DSRC-based ITS uses. By 2003, DSRC was used in Europe and Japan for electronic toll collection. In August 2008, the European Telecommunications Standards Institute (ETSI) allocated 30 MHz of spectrum in the 5.9 GHz band for ITS. In November 2020, the FCC reallocated the lower 45 MHz of the 75 MHz spectrum to the neighboring 5.8 GHz ISM band for unlicensed non-ITS uses, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Radiated Power
Effective radiated power (ERP), synonymous with equivalent radiated power, is an IEEE standardized definition of directional radio frequency (RF) power, such as that emitted by a radio transmitter. It is the total power in watts that would have to be radiated by a half-wave dipole antenna to give the same radiation intensity (signal strength or power flux density in watts per square meter) as the actual source antenna at a distant receiver located in the direction of the antenna's strongest beam (main lobe). ERP measures the combination of the power emitted by the transmitter and the ability of the antenna to direct that power in a given direction. It is equal to the input power to the antenna multiplied by the gain of the antenna. It is used in electronics and telecommunications, particularly in broadcasting to quantify the apparent power of a broadcasting station experienced by listeners in its reception area. An alternate parameter that measures the same thing is eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Telecommunications Commission
The National Telecommunications Commission (NTC; ) is the telecommunications regulator of the Philippines. It is an attached agency of the Department of Information and Communications Technology responsible for the supervision, adjudication and control over all telecommunications services and radio and television networks throughout the country. History The National Telecommunications Commission (NTC) was created under Executive Order No. 546 promulgated on July 23, 1979, and conferred with regulatory and quasi-judicial functions taken over from the Board of Communications and the Telecommunications Control Bureau, which were abolished in the same Order. Primarily, the NTC is the sole body that exercises jurisdiction over the supervision, adjudication and control over all telecommunications services and television networks throughout the country. For the effective enforcement of this responsibility, it adopts and promotes guidelines, rules, and regulations on the establishme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ministry Of Internal Affairs And Communications
The is a Cabinet (government), cabinet-level ministry in the Government of Japan. Its English name was Ministry of Public Management, Home Affairs, Posts and Telecommunications (MPHPT) prior to 2004. It is housed in the 2nd Building of the Central Common Government Office at 2-1-2 Kasumigaseki in Chiyoda, Tokyo, Chiyoda, Tokyo, Japan. The Ministry oversees the Japanese administrative system, manages local governments, elections, telecommunication, post, and governmental statistics. The is appointed from among the members of the cabinet. History The Ministry was created on January 6, 2001, by the merger of the , the and the Management and Coordination Agency (総務庁). Certain functions of the Management and Coordination Agency were transferred to the Cabinet Office (Japan), Cabinet Office in this process, while many functions of the MPT were transferred to an independent Postal Services Agency which later became Japan Post. Subdivisions The Ministry has the following subdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association Of Radio Industries And Businesses
The , commonly known as , is a standardization organization in Japan. ARIB is designated as the center for promotion of the efficient use of the radio spectrum and the designated frequency change support agency. Its activities include those previously performed by the Research and Development Center for Radio Systems (RCR) and the Broadcasting Technology Association (BTA). ARIB is a participating standards organization of the Global Standards Collaboration initiative and an organizational partner of the 3rd Generation Partnership Project (3GPP). See also *ISDB Integrated Services Digital Broadcasting (ISDB; Japanese: , ''Tōgō dejitaru hōsō sābisu'') is a Japanese broadcasting standard for digital television (DTV) and digital radio. ISDB supersedes both the NTSC-J analog television system and ... References https://www.arib.or.jp/english/arib/about_arib.html - Establishment of ARIB External links * ISDB Trade associations based in Japan Radio orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ETSI
The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization operating in the field of Information and communications technology, information and communications. ETSI supports the development and testing of global technical standards for ICT-enabled systems, applications and services. Overview and history ETSI was set up in 1988 by the European Conference of Postal and Telecommunications Administrations (European Conference of Postal and Telecommunications Administrations, CEPT) following a proposal from the European Commission (EC). ETSI is the officially recognized body with a responsibility for the standardization of information and communication technologies (ICT). It is one of the three bodies officially recognized by the European Union as a European Standards Organisation (ESO), the others being European Committee for Standardization, CEN and CENELEC. The role of the ESOs is to support EU regulation and policies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ofcom
The Office of Communications, commonly known as Ofcom, is the government-approved regulatory and competition authority for the broadcasting, internet, telecommunications and mail, postal industries of the United Kingdom. Ofcom has wide-ranging powers across the television, radio, telecoms, internet and postal sectors. It has a statutory duty to represent the interests of citizens and consumers by promoting competition and protecting the public from harmful or offensive material. Some of the main areas Ofcom regulates are TV and radio standards, broadband and phones, video-sharing platforms online, the wireless spectrum and postal services. The regulator was initially established by the (c. 11) and received its full authority from the Communications Act 2003 (c. 21). History On 20 June 2001, the Queen's Speech to the Parliament of the United Kingdom, UK Parliament announced the creation of Ofcom. The new body, which was to replace several existing authorities, was concei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Doppler Weather Radar
Terminal Doppler Weather Radar (TDWR) is a Doppler weather radar system with a three-dimensional "pencil beam" used primarily for the detection of hazardous wind shear conditions, precipitation, and winds aloft on and near major airports situated in climates with great exposure to thunderstorms in the United States. As of 2011, all were in-service with 45 operational radars, some covering multiple airports in major metropolitan locations, across the United States & Puerto Rico. Several similar weather radars have also been sold to other countries such as China (Hong Kong). Funded by the United States Federal Aviation Administration (FAA), TDWR technology was developed in the early 1990s at Lincoln Laboratory, part of the Massachusetts Institute of Technology, to assist air traffic controllers by providing real-time wind shear detection and high-resolution precipitation data. The primary advantage of TDWRs over previous weather radars is that it has a finer range resolution—me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Control
Power control, broadly speaking, is the intelligent selection of transmitter power output in a communication system to achieve good performance within the system. Guowang Miao, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data Networks, Cambridge University Press, , 2016. The notion of "good performance" can depend on context and may include optimizing metrics such as link data rate, network capacity, outage probability, geographic coverage and range, and life of the network and network devices. Power control algorithms are used in many contexts, including cellular networks, sensor networks, wireless LANs, and DSL modems. Transmit power control Transmit power control is a technical mechanism used within some networking devices in order to prevent too much unwanted interference between different wireless networks (e.g. the owner's network and the neighbour's network). It is also essential component in case of cognitive radio networks deployed in a distribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
