Television Companies in the United States
Television is one of the major mass media of the United States. As a whole, the television networks of the United States are the largest and most syndicated in the world.
Television channels and networks
In the United States television is available via broadcast (over-the-air), unencrypted satellite (free-to-air), direct broadcast satellite, cable television, and IPTV (internet protocol television).
Over-the-air and free-to-air TV is free with no monthly payments while cable, direct broadcast satellite, and IPTV require a monthly payment that varies depending on how many channels a subscriber chooses to pay for. Channels are usually sold in groups, rather than singly.
Broadcast television
The United States has a decentralized, market-oriented television system. The United States has a national public broadcast service known as the Public Broadcasting Service (PBS). Local media markets have their own television stations, which may be affiliated with or owned and operated by a TV network. Stations may sign affiliation agreements with one of the national networks. Except in very small markets with few stations, affiliation agreements are usually exclusive: if a station is an NBC affiliate, the station would not air programs from ABC, CBS or other networks.
Major broadcast networks
The five major U. S. networks are NBC, CBS, ABC, Fox, and the CW. The first three began as radio networks: NBC and CBS in the 1920s, and ABC was spun off from NBC in 1943. Fox is a relative newcomer that began in 1986, although it is built upon the remnants of the former DuMont Television Network, which was an earlier fourth network that operated from 1948 to 1956. The CW was created in 2006 when UPN merged with the terrestrial and cable assets of the WB (the WB’s online assets remain separate). All in all, the US broadcasting landscape dramatically evolved towards a conglomeration of players, an effect also called Concentration of media ownership which describes the narrowing-down of competing businesses in modern television broadcasting.
Non-commercial television
Public television has a far smaller role than in most other countries. There is no federal state-owned broadcasting authority directed at U. S. audiences because of prohibitions set forth in the Smith-Mundt Act. The federal government does produce NASA TV (three channels featuring space program information and educational programs) and the Pentagon Channel (a military news outlet) for public consumption, but distributes them only via satellite and internet and not through terrestrial outlets.
American public television stations air programming that commercial stations do not offer, such as educational, cultural and arts, and public affairs programming. Most public TV stations are affiliates of the Public Broadcasting Service, sharing programs like Sesame Street and Masterpiece Theatre. Unlike the commercial networks, PBS does not officially produce any of its own programming; instead, individual PBS stations, station groups and affiliated producers create programming and provide these through PBS to other affiliates; there are also a number of syndicators dealing exclusively or primarily with public broadcast stations, both PBS and independent stations.
Cable television
Unlike broadcast networks, most cable networks air the same programming nationwide. Top cable networks include USA Network (general entertainment), ESPN and Fox Sports (sports), MTV (music and reality TV), CNN and Fox News (news), Syfy (science fiction), Disney Channel (family), Nickelodeon and Cartoon Network (Children’s), Discovery Channel and Animal Planet (documentaries), TBS (comedy), TNT and FX (drama) and Lifetime (women’s).
Internet services
IPTV is similar to a cable subscription, but instead of the set-top box receiving information via a dedicated wire, video is transmitted over the public internet or private internet protocol-based network to a set-top box.
Web television began in the 1990s and has become popular in the 2000s, resulting in a trend of cord cutting— canceling cable subscription in favor of online content, over-the-air broadcasts, and DVD rental. Web TV providers in the United States include Hulu, Netflix (which was originally a mail-order DVD rental service), MyTV (Arabic), and many international web sites such as YouTube, Myspace, Newgrounds, Blip, and Crackle. Viewers can watch these programs from any web browser, whether on a desktop computer, laptop, tablet, or smartphone. Mobile television services also include mobile apps for both traditional and new programming providers, usually optimized for a small screen and mobile bandwidth constraints. Mobile video is available for direct download or streaming from the iTunes Store, Google Play, and Amazon Instant Video.
Words & Expressions
unencrypted：未加密的
free-to-air：免费接收
decentralize：权力分散
terrestrial：地面的
conglomeration：聚集
anatomy：解剖，剖析，分析
set-top box：机顶盒
optimize：最优化