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Quad Band
In telecommunications, a multi-band device (including (2) dual-band, (3) tri-band, (4) quad-band and (5) penta-band devices) is a communication device (especially a mobile phone) that supports multiple radio frequency bands. All devices which have more than one channel use multiple frequencies; a band however is a group of frequencies containing many channels. Multiple bands in mobile devices support roaming between different regions where different standards are used for mobile telephone services. Where the bands are widely separated in frequency, parallel transmit and receive signal path circuits must be provided, which increases the cost, complexity and power demand of multi-band devices. The term quad-band describes a device that supports four frequency bands: the 850 and 1900 MHz bands, which are used in the Americas, and 900 / 1800, which are used in most other parts of the world. Most GSM/UMTS phones support all four bands, while most CDMA2000/1xRTT phones (mostly North A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Timeport L7089
Motorola, Inc. () was an American Multinational corporation, multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul Galvin (businessman), Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been radio-related communication equipment such as two-way radios, consumer Walkie-talkie, walkie-talkies, Cellular network, cellular infrastructure, Cellular phones, mobile phones, satellite communicators, pagers, as well as cable modems and semiconductors. After having lost $4.3 billion from 2007 to 2009, Motorola was split into two independent public companies: Motorola Solutions (its legal successor) and Motorola Mobility (spun off), on January 4, 2011. Motorola designed and sold wireless network equipment such as Cellular network, cellular transmission base stations and signal amplifiers. Its business and government customers consisted mainly of wireless voice and broadband systems (used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attenuation
In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a Transmission medium, medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates. Hearing protection device, Hearing protectors help reduce Sound power, acoustic flux from flowing into the ears. This phenomenon is called acoustic attenuation and is measured in decibels (dBs). In electrical engineering and telecommunications, attenuation affects the Wave propagation, propagation of waves and signals in electrical circuits, in optical fibers, and in air. Attenuator (electronics), Electrical attenuators and optical attenuators are commonly manufactured components in this field. Background In many cases, attenuation is an exponential function of the path length through the medium. In optics and in chemical spectroscopy, this is known as the Beer–Lambert law. In engineering, attenu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSM Frequency Bands
GSM frequency bands or frequency ranges are the cellular frequencies designated by the International Telecommunication Union, ITU for the operation of GSM mobile phones and other mobile devices. Frequency bands GSM frequency usage around the world A dual-band 900/1800 device is required to be compatible with most networks apart from deployments in ITU Region 2. GSM-900, EGSM/EGSM-900 and GSM-1800 GSM-900 and GSM-1800 are used in most parts of the world (ITU-Regions 1 and 3): Africa, Europe, Middle East, Asia (apart from Japan and South Korea where GSM has never been introduced) and Oceania. In common GSM-900 is most widely used. Fewer operators use GSM-1800. Mobile phones on aircraft, Mobile Communication Services on Aircraft (MCA) uses GSM-1800. In some countries GSM-1800 is also referred to as "Digital Cellular System" (DCS). GSM-850 and GSM-1900 GSM-1900 and GSM-850 are used in most of North, South and Central America (ITU-Region 2). In North America, GSM operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of UMTS Networks
The following is a list of mobile telecommunications networks using third-generation Universal Mobile Telecommunications System (UMTS) technology. This list does not aim to cover all networks, but instead focuses on networks deployed on frequencies other than 2100 MHz which is commonly deployed around the globe and on Multiband deployments. General information * For technical details on UMTS and a list of its designated operating frequencies, bands, and their common names, see UMTS frequency bands. * Networks on the global UMTS-bands 1 and 8 are suitable for global roaming in ITU Regions 1, 2 (some countries) and 3. * Networks on UMTS-bands 2 and 4 allow roaming in ITU Region 2 (Americas) only. * Networks on UMTS band 5 are suitable for roaming in ITU Regions 2 and 3 (single countries). Europe, Middle East & Africa (EMEA) Networks in Europe, the Middle East and Africa are exclusively deployed on 2100 MHz (Band 1) and/or 900 MHz (Band 8). Americas Carib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-Mobile US
T-Mobile US, Inc. is an American wireless network operator headquartered in Bellevue, Washington. Its majority shareholder and namesake is the German telecommunications company Deutsche Telekom. T-Mobile is the second largest wireless carrier in the United States, with 131 million subscribers as of March 31, 2025. The company was founded in 1994 by John W. Stanton of the Western Wireless Corporation as VoiceStream Wireless. Deutsche Telekom then gained plurality ownership in 2001 and renamed it after its global T-Mobile brand. , the German company holds a 51.4% stake in the company. T-Mobile US operates two main brands: T-Mobile and Metro by T-Mobile (acquired in a 2013 reverse takeover of MetroPCS that also led to T-Mobile's listing on the NASDAQ). In 2020, T-Mobile expanded through the acquisition of Sprint, which also made T-Mobile the operator of Assurance Wireless, a service subsidized by the federal Lifeline program. The company's growth continued in 2024 wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrum Repacking
A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. In the optical spectrum, light wavelength is viewed as continuous, and spectral colors are seen to blend into one another smoothly when organized in order of their corresponding wavelengths. As scientific understanding of light advanced, the term came to apply to the entire electromagnetic spectrum, including radiation not visible to the human eye. ''Spectrum'' has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adjacent-channel Interference
Adjacent-channel interference (ACI) is interference caused by extraneous power from a signal in an adjacent channel. ACI may be caused by inadequate filtering (such as incomplete filtering of unwanted modulation products in FM systems), improper tuning or poor frequency control (in the reference channel, the interfering channel or both). ACI is distinguished from crosstalk. Origin The adjacent-channel interference which receiver A experiences from a transmitter B is the sum of the power that B emits into A's channel—known as the "unwanted emission", and represented by the ACLR (Adjacent Channel Leakage Ratio)—and the power that A picks up from B's channel, which is represented by the ACS (Adjacent Channel Selectivity). B emitting power into A's channel is called adjacent-channel leakage (unwanted emissions). It occurs for two reasons. First, because RF filters require a roll-off, and do not eliminate a signal completely. Second, due to intermodulation in B's amplifiers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verizon Wireless
Verizon is an American wireless network operator that previously operated as a separate division of Verizon Communications under the name Verizon Wireless. In a 2019 reorganization, Verizon moved the wireless products and services into the divisions Verizon Consumer and Verizon Business, and stopped using the Verizon Wireless name. Verizon is the largest wireless carrier in the United States, with 146 million subscribers as of March 31, 2025. It currently has the second-largest network in the United States with their LTE network covering 2.68 million sq. miles of the United States. The company is headquartered in Basking Ridge, New Jersey. It was founded in 2000 as a joint venture of American telecommunications firm Bell Atlantic, which would soon become Verizon Communications, and British multinational telecommunications company Vodafone. Verizon Communications became the sole owner in 2014 after buying Vodafone's 45-percent stake in the company. It operates national 5G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northeast Corridor
The Northeast Corridor (NEC) is an electrified railroad line in the Northeast megalopolis of the United States. Owned primarily by Amtrak, it runs from Boston in the north to Washington, D.C., in the south, with major stops in Providence, Rhode Island, Providence, New Haven, Connecticut, New Haven, Stamford, Connecticut, Stamford, New York City, Newark, New Jersey, Newark, Trenton, New Jersey, Trenton, Philadelphia, Wilmington, Delaware, Wilmington, and Baltimore. The NEC is roughly paralleled by Interstate 95 for most of its length. Carrying more than 2,200 trains a day, it is the busiest passenger rail line in the United States by ridership and service frequency. The corridor is used by many Amtrak trains, including the high-speed ''Acela'' (formerly ''Acela Express''), intercity trains, and several Long-distance Amtrak routes, long-distance trains. Most of the corridor also has frequent Commuter rail in North America, commuter rail service, operated by the MBTA Commuter Rail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an international border with the Mexico, Mexican state of Baja California to the south. With almost 40million residents across an area of , it is the List of states and territories of the United States by population, largest state by population and List of U.S. states and territories by area, third-largest by area. Prior to European colonization of the Americas, European colonization, California was one of the most culturally and linguistically diverse areas in pre-Columbian North America. European exploration in the 16th and 17th centuries led to the colonization by the Spanish Empire. The area became a part of Mexico in 1821, following Mexican War of Independence, its successful war for independence, but Mexican Cession, was ceded to the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pay TV
Pay television, also known as subscription television, premium television or, when referring to an individual service, a premium channel, refers to subscription-based television services, usually provided by multichannel television providers, but also increasingly via digital terrestrial and streaming television. In the United States, subscription television began in the late 1970s and early 1980s in the form of encrypted analog over-the-air broadcast television which could be decrypted with special equipment. The concept rapidly expanded through the multi-channel transition and into the post-network era. Other parts of the world beyond the United States, such as France and Latin America have also offered encrypted analog terrestrial signals available for subscription. The term is most synonymous with premium entertainment services focused on films or general entertainment programming such as, in the United States, Cinemax, HBO, MGM+, Showtime, and Starz, but such servic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MediaFLO
MediaFLO was a technology developed by Qualcomm for transmitting audio, video and data to portable devices such as mobile phones and personal televisions, used for mobile television. Qualcomm operated a mobile pay television service, FLO TV, from 2007 to 2011 using this technology. Broadcast data transmitted via MediaFLO includes live, real time audio and video streams, as well as scheduled video and audio clips and shows. The technology could also carry Internet Protocol datacast application data, such as stock market quotes, sports scores, and weather reports. In October 2010, Qualcomm announced it was suspending new sales of the service to consumers. In December 2010, AT&T announced that it will purchase Qualcomm's FCC licenses in the 700 MHz band. FLO TV discontinued service on March 27, 2011. History Devices featuring MediaFLO were introduced by LG and Samsung at the 2006 Consumer Electronics Show. On December 1, 2005, Verizon Wireless and Qualcomm announced a par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
