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Communications, Air-interface, Long And Medium Range
Communications access for land mobiles (CALM) is an initiative by the ISO TC 204/Working Group 16 to define a set of wireless communication protocols and air interfaces for a variety of communication scenarios spanning multiple modes of communications and multiple methods of transmissions in Intelligent Transportation System (ITS). The CALM architecture is based on an IPv6 convergence layer that decouples applications from the communication infrastructure. A standardized set of air interface protocols is provided for the best use of resources available for short, medium and long-range, safety critical communications, using one or more of several media, with multipoint (mesh) transfer. Since 2007 CALM stands for Communication Access for Land Mobile, before that year, CALM stood for Communications, Air-interface, Long and Medium range. Communication Modes CALM enables the following communication modes: * Vehicle-to-Infrastructure (V2I): communication initiated by either roadside or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intelligent Transportation System
An intelligent transportation system (ITS) is an advanced application that aims to provide services relating to different modes of transport and traffic management and enable users to be better informed and make safer, more coordinated, and 'smarter' use of transport networks. Some of these technologies include calling for emergency services when an accident occurs, using cameras to enforce traffic laws or signs that mark speed limit changes depending on conditions. Although ITS may refer to all modes of transport, the directive of the European Union 2010/40/EU, made on July 7, 2010, defined ITS as systems in which information and communication technologies are applied in the field of road transport, including infrastructure, vehicles and users, and in traffic management and mobility management, as well as for interfaces with other modes of transport. ITS may be used to improve the efficiency and safety of transport in many situations, i.e. road transport, traffic management, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPv6
Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion, and was intended to replace IPv4. In December 1998, IPv6 became a Draft Standard for the IETF, which subsequently ratified it as an Internet Standard on 14 July 2017. Devices on the Internet are assigned a unique IP address for identification and location definition. With the rapid growth of the Internet after commercialization in the 1990s, it became evident that far more addresses would be needed to connect devices than the 4,294,967,296 (232) IPv4 address space had available. By 1998, the IETF had formalized the successor protocol, IPv6 which uses 128-bit addresses, theoretically all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics (computer science), semantics, and synchronization of communication and possible Error detection and correction, error recovery methods. Protocols may be implemented by Computer hardware, hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be Implementation, implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DSRC
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] |
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] |
CALM M5
CALM M5 is the ISO 21215 standard that incorporates WAVE (WAVE PHY/MAC is IEEE 802.11p standard) and adds the following features: * Global (European) 5 GHz spectrum * Regulatory domain (border) management * Directivity and EMC control * Regional DSRC 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 ... cooperation * Multiple radios/interfaces/antenna management through network connection * GPRS/UMTS/+++ network interconnectivity See also * IEEE 802.11p References Status of Project IEEE 802.11p* Bob Williams, ''Intelligent Transport Systems Standards'', p. 221, Artech House, 2008 . * Piyushimita (Vonu) Thakuriah, D. Glenn Geers, ''Transportation and Information: Trends in Technology and Policy'', p. 24, Springer, 2013 . IEEE 802.11 {{Telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WiMAX
Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options. The WiMAX Forum was formed in June 2001 to promote conformity and interoperability, including the definition of system profiles for commercial vendors. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL". WiMAX was initially designed to provide 30 to 40 megabit-per-second data rates, with the 2011 update providing up to 1 Gbit/s for fixed stations. IEEE 802.16m or Wireless MAN-Advanced was a candidate for 4G, in competition with the LTE Advanced standard. WiMAX release 2.1, popularly branded as WiMAX 2+, is a backwards-compatible transition from previous WiMAX generations. It is compatible and interoperable with TD-LTE. Newer versions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to . It employs Ultra high frequency, UHF radio waves in the ISM bands, from 2.402GHz to 2.48GHz. It is mainly used as an alternative to wired connections to exchange files between nearby portable devices and connect cell phones and music players with wireless headphones, wireless speakers, HIFI systems, car audio and wireless transmission between TVs and soundbars. Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which has more than 35,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The Institute of Electrical and Electronics Engineers, IEEE standardized Bluetooth as IEEE 802.15.1 but no longer maintains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RFID
Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods. Passive tags are powered by energy from the RFID reader's interrogating radio waves. Active tags are powered by a battery and thus can be read at a greater range from the RFID reader, up to hundreds of meters. Unlike a barcode, the tag does not need to be within the line of sight of the reader, so it may be embedded in the tracked object. RFID is one method of automatic identification and data capture (AIDC). RFID tags are used in many industries. For example, an RFID tag attached to an automobile during product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
