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Mass Call Event
A mass call event or mass calling event (also MCE in telephony usage) is a situation in which an extraordinarily high number of telephone calls are attempted into or out of an area, causing tremendous network congestion, and therefore service which is either significantly degraded or potentially almost completely unavailable. The term is typically used with mobile telephony systems, in which there are simply not enough radio channels available in a given cell or cells. This causes blocked calls or dropped calls. However, it can also apply to landline phones, in which not enough trunking telephone circuits are available into and out of any given telephone exchange or equivalent switching office at any level of the public switched telephone network (PSTN). An MCE is typically caused by a sudden disaster of some sort, such as an earthquake or explosion. One of the earliest examples was the Iroquois Theatre Fire in Chicago in 1903. The 1963 Kennedy assassination represented a mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephony
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the invention and development of the telephone. Telephony is commonly referred to as the construction or operation of telephones and telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sound between points, with or without the use of wires. The term is also used frequently to refer to computer hardware, software, and computer network systems, that perform functions traditionally performed by telephone equipment. In this context the technology is specifically referred to as Internet telephony, or voice over Internet Protocol (VoIP). Overview The first telephones were connected directly in pairs. Each user had a separate telephone wired ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kennedy Assassination
John F. Kennedy John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK and the nickname Jack, was an American politician who served as the 35th president of the United States from 1961 until his assassination ..., the 35th president of the United States, was Assassination, assassinated on Friday, November 22, 1963, at 12:30 p.m. Central Time Zone, CST in Dallas, Dallas, Texas, while riding in a presidential motorcade through Dealey Plaza. Kennedy was in the vehicle with his wife, Jacqueline Kennedy Onassis, Jacqueline, Texas Governor John Connally, and Connally's wife, Nellie Connally, Nellie, when he was fatally shot from the nearby Texas School Book Depository by Lee Harvey Oswald, a former US Marine. Governor Connally was seriously wounded in the attack. The motorcade rushed to Parkland Memorial Hospital, where Kennedy was pronounced dead about 30 minutes after the shooting; Connally recovered. About 70 minutes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandwidth (computing)
In computing, bandwidth is the maximum rate of data transfer across a given path. Bandwidth may be characterized as network bandwidth, data bandwidth, or digital bandwidth. This definition of ''bandwidth'' is in contrast to the field of signal processing, wireless communications, modem data transmission, digital communications, and electronics, in which ''bandwidth'' is used to refer to analog signal bandwidth measured in hertz, meaning the frequency range between lowest and highest attainable frequency while meeting a well-defined impairment level in signal power. The actual bit rate that can be achieved depends not only on the signal bandwidth but also on the noise on the channel. Network capacity The term ''bandwidth'' sometimes defines the net bit rate 'peak bit rate', 'information rate,' or physical layer 'useful bit rate', channel capacity, or the maximum throughput of a logical or physical communication path in a digital communication system. For example, bandwidth test ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text Messaging
Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and numeric characters, between two or more users of mobile devices, desktops/laptops, or another type of compatible computer. Text messages may be sent over a cellular network, or may also be sent via an Internet connection. The term originally referred to messages sent using the Short Message Service (SMS). It has grown beyond alphanumeric text to include multimedia messages using the Multimedia Messaging Service (MMS) containing digital images, videos, and sound content, as well as ideograms known as emoji ( happy faces, sad faces, and other icons), and instant messenger applications (usually the term is used when on mobile devices). Text messages are used for personal, family, business and social purposes. Governmental and non-governmental organizations use text messaging for communication between colleagues. In the 2010s, the sending of short informal mes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public-safety Answering Point
A public-safety answering point (PSAP), sometimes called public-safety access point, is a call center where emergency/non-emergency calls (like police, fire brigade, ambulance) initiated by any mobile or landline subscriber are terminated. It can also happen that when 112 is dialed in then a logic is implemented by mobile or network operators to route the call to the nearest police station. It is a call center in almost all the countries including Canada and the United States responsible for answering calls to an emergency telephone number for police, firefighting, and ambulance services. Trained telephone operators are also usually responsible for dispatching these emergency services. Most PSAPs are now capable of caller location for landline calls, and many can handle mobile phone locations as well (sometimes referred to as phase II location), where the mobile phone company has a handset to location system. Some can also use voice broadcasting where outgoing voice mail can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emergency Call
Most public switched telephone networks have a single emergency telephone number (sometimes known as the universal emergency telephone number or the emergency services number) that allows a caller to contact local emergency services for assistance. The emergency number differs from country to country; it is typically a three-digit number so that it can be easily remembered and dialed quickly. Some countries have a different emergency number for each of the different emergency services; these often differ only by the last digit. In many countries, dialing either 1-1-2 (used in Europe and parts of Asia) or 9-1-1 (used in the Americas) will connect callers to emergency services. For individual countries, see the list of emergency telephone numbers. Configuration and operation The emergency telephone number is a special case in the country's telephone number plan. In the past, calls to the emergency telephone number were often routed over special dedicated circuits. Though with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emergency Responder
A certified first responder is a person who has completed a course and received certification in providing pre-hospital care for medical emergencies. Certified individuals should have received much more instruction than someone who is trained in basic first aid and cardiopulmonary resuscitation (CPR) but they are not necessarily a substitute for more advanced emergency medical care rendered by emergency medical technicians (EMTs) and paramedics. First responders typically provide advanced first aid level care, CPR, and automated external defibrillator (AED) usage. The term "certified first responder" is not to be confused with "first responder", which is a generic term referring to the first medically trained responder to arrive on scene ( EMS, police, fire) and medically trained telecommunication operators who provide pre-arrival medical instructions as trained Emergency Medical Dispatchers (EMD). Many police officers and firefighters are required to receive training as certi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Safety
Public security or public safety is the prevention of and protection from events that could endanger the safety and security of the public from significant danger, injury, or property damage. It is often conducted by a state government to ensure the protection of citizens, persons in their territory, organizations, and institutions against threats to their well-being, survival, and prosperity. The public safety issues that a municipality, county, regional, or federal jurisdiction may handle include crimes (ranging from misdemeanors to felonies), structure fires, conflagrations, medical emergencies, mass-casualty incidents, disasters, terrorism, and other concerns. Public safety organizations are organizations that conduct public safety. They generally consist of emergency services and first responders such as law enforcement, fire services, emergency medical services, security forces, and military forces. They are often operated by a government, though some private public safe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Phone Company
A mobile network operator (MNO), also known as a wireless service provider, wireless carrier, cellular company, or mobile network carrier, is a provider of wireless communications services that owns or controls all the elements necessary to sell and deliver services to an end user, including radio spectrum allocation, wireless network infrastructure, back haul infrastructure, billing, customer care, provisioning computer systems, and marketing and repair organizations. Operator In addition to obtaining revenue by offering retail services under its own brand, an MNO may also sell access to network services at wholesale rates to mobile virtual network operators (MVNO). A key defining characteristic of a mobile network operator is that an MNO must own or control access to a radio spectrum license from a regulatory or government entity. A second key defining characteristic of an MNO is that it must own or control the elements of the network infrastructure necessary to provide ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detonation
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with speeds in the range of 1 km/sec and differ from deflagrations which have subsonic flame speeds in the range of 1 m/sec. Detonations occur in both conventional solid and liquid explosives, as well as in reactive gases. The velocity of detonation in solid and liquid explosives is much higher than that in gaseous ones, which allows the wave system to be observed with greater detail (higher resolution). A very wide variety of fuels may occur as gases (e.g. hydrogen), droplet fogs, or dust suspensions. In addition to dioxygen, oxidants can include halogen compounds, ozone, hydrogen peroxide and oxides of nitrogen. Gaseous detonations are often associated with a mixture of fuel and oxidant in a composition somewhat below conventional flammabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remote Control
In electronics, a remote control (also known as a remote or clicker) is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such as a television set, DVD player or other home appliance. A remote control can allow operation of devices that are out of convenient reach for direct operation of controls. They function best when used from a short distance. This is primarily a convenience feature for the user. In some cases, remote controls allow a person to operate a device that they otherwise would not be able to reach, as when a garage door opener is triggered from outside. Early television remote controls (1956–1977) used ultrasonic tones. Present-day remote controls are commonly consumer infrared devices which send digitally-coded pulses of infrared radiation. They control functions such as power, volume, channels, playback, track change, heat, fan speed, and vario ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journalist
A journalist is an individual that collects/gathers information in form of text, audio, or pictures, processes them into a news-worthy form, and disseminates it to the public. The act or process mainly done by the journalist is called journalism. Roles Journalists can be broadcast, print, advertising, and public relations personnel, and, depending on the form of journalism, the term ''journalist'' may also include various categories of individuals as per the roles they play in the process. This includes reporters, correspondents, citizen journalists, editors, editorial-writers, columnists, and visual journalists, such as photojournalists (journalists who use the medium of photography). A reporter is a type of journalist who researches, writes and reports on information in order to present using sources. This may entail conducting interviews, information-gathering and/or writing articles. Reporters may split their time between working in a newsroom, or from home, and going ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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