In electronics, a crossbar switch is a collection of switches arranged in a matrix configuration. A crossbar switch has multiple input and output lines that form a crossed pattern of interconnecting lines between which a connection may be established by closing a switch located at each intersection, the elements of the matrix. Originally, a crossbar switch consisted literally of crossing metal bars that provided the input and output paths. Later implementations achieved the same switching topology in solid state semiconductor chips. The cross-point switch is one of the principal switch architectures, together with a rotary switch, memory switch, and a crossover switch.
Texarkana is a city in Arkansas and the county seat of Miller County. The city is located across the state line from its twin city, Texarkana, Texas. The city was founded at a railroad intersection on December 8, 1873, and was incorporated in Arkansas on August 10, 1880. Texarkana is the principal city of the Texarkana metropolitan area, which is ranked 274th in terms of population in the United States with 150,098 in 2016 according to the United States Census Bureau.
Texarkana is a city in Bowie County, Texas, United States, located in the Ark-La-Tex region. Located approximately 180 miles (290 km) from Dallas, Texarkana is a twin city with neighboring Texarkana, Arkansas. The population of the Texas city was 37,679 at the 2016 census estimate. The city and its Arkansas counterpart form the core of the Texarkana Metropolitan Statistical Area, encompassing all of Bowie County, Texas, and Miller County, Arkansas. The two cities had a combined population of 67,592 at the 2017 census, and the metropolitan area had a total population of 150,098.
A nonblocking minimal spanning switch is a device that can connect N inputs to N outputs in any combination. The most familiar use of switches of this type is in a telephone exchange. The term "non-blocking" means that if it is not defective, it can always make the connection. The term "minimal" means that it has the fewest possible components, and therefore the minimal expense.
Anchor Exchange was an underground, hardened telephone exchange built in Birmingham, England. Construction commenced in 1953 under the guise of building an underground railway and opened in September 1957 at a cost of £4 million. It was located nominally on Newhall St. However its network of tunnels extended from at least the Jewellery Quarter to Southside.
Texarkana Regional Airport, also known as Webb Field, is a public use airport located three nautical miles (6 km) northeast of the central business district of Texarkana, a city in Miller County, Arkansas, United States. It is owned by the Texarkana Airport Authority. The airport is located within the city limits of Texarkana, roughly 3 miles east of State Line Avenue. The front gate opens to the northwest, at the intersection of Arkansas Boulevard and U.S. Route 67. A Union Pacific Railroad line runs parallel to US 67 on the side of the highway facing the airport. It is mostly used for general aviation, but is also served by American Eagle.
A marker is a type of special purpose control system that was used in electromechanical telephone central office switches. Switches employing markers belong to a class of switches known as "common control", as the purpose of a marker is to control the closure of contacts in the switching fabric that connect a circuit between the calling party and the called party. This is in contrast to "direct control" switches, where the switching elements were controlled directly by the customer's dial, such as the Step by Step switch. The term marker came from its use to mark a path of links through the switching fabric. A marker's comprehensive view of the switching fabric allowed it to find and assemble a path from one terminal to another, if the links were available, unlike the earlier graded progressive systems in which a path might not be found.
The Texarkana, AR–Texarkana, TX Metropolitan Statistical Area (MSA), as defined by the United States Office of Management and Budget, is a two-county region anchored by the twin cities of Texarkana, Texas and Texarkana, Arkansas, and encompassing the surrounding communities in Bowie County, Texas and Miller County, Arkansas. As of the 2016 census, the MSA had a population of 150,098. Texarkana is a subset of the broader Ark-La-Tex region.
A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them. Sealed in a long, narrow glass tube, the contacts are protected from corrosion. The glass envelope may contain multiple reed switches or multiple reed switches can be inserted into a single bobbin and actuate simultaneously. Reed switches have been manufactured since the 1930s.
A class-4, or tandem, telephone switch is a U.S. telephone company central office telephone exchange used to interconnect local exchange carrier offices for long distance communications in the public switched telephone network.
The Number One Crossbar Switching System, was the primary technology for designing urban telephone exchanges in the Bell System in the mid-20th century. Its switch fabric used the new electromechanical crossbar switch to implement the topology of the panel switching system of the 1920s. The first 1XB system was installed in the PResident-2 office at Troy Avenue in Brooklyn, New York which became operational in February 1938.
The Connections Museum, is located in Centurylink's Duwamish Central Office at East Marginal Way S. and Corson Avenue S. in Georgetown, Seattle, Washington. It "reveals the history of the telephone and the equipment that makes it all work." The museum was originally sponsored by the Washington Telecom Pioneers, and is now a part of the Telecommunications History Group, based in Denver, CO. It features vintage equipment from AT&T, Western Electric, Pacific Northwest Bell, USWest, and other organizations.
A telephone exchange is a telecommunications system used in the public switched telephone network or in large enterprises. An exchange consists of electronic components and in older systems also human operators that interconnect (switch) telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers.
Arkansas' transportation system is used to move Arkansans throughout the state, and out of state travelers across the state.
A group switching centre (GSC) was a United Kingdom telephone exchange used to provide local and trunk routing to local exchanges within its own and if required, adjacent group areas. It formed a component of the trunk mechanisation hierarchy that was commenced in 1939. The concept of group switching centres became important with the introduction in the United Kingdom of subscriber trunk dialling (STD) in 1958, initially from Bristol central telephone exchange. They were typically located towards the centre of their corresponding group area, usually in a large town or city, and serviced a group of local and dependent telephone exchanges within their home and adjacent group areas. From 1 January 1958, the British network was divided into 639 charging groups. These areas provided the basis for tariff calculations for telephone calls.
Mondial House was a main telecommunications hub in central London on the banks of the River Thames. It was known as an international switching centre (ISC). Built in 1978 the building was seen as controversially modern-looking. It was demolished in 2006.
