A broadcast auxiliary service or BAS is any radio frequency system used by a radio station or TV station, which is not part of its direct

broadcast Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum ( radio waves), in a one-to-many model. Broadcasting began ...

to listeners or viewers. These are essentially internal-use backhaul channels not intended for actual reception by the public, but part of the airchain required to get those signals back to the broadcast studio from the field. usually to be integrated into a live production. Examples include: *

studio/transmitter link A studio transmitter link (or STL) sends a radio station's or television station's audio and video from the broadcast studio or origination facility to a radio transmitter, television transmitter or uplink facility in another location. This is ...

(STL) * transmitter/studio link (TSL) * remote pickup unit (RPU) * electronic news gathering (ENG) Several of these bands exist, but the most frequently used band is the 2 GHz microwave BAS band for point-to-point transmission from mobile newsgathering units to mountaintop receivers. Seven 12-MHz wide channels exist in the band. In North America,

DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in Singapore in Febr ...

, precisely the same modulation technique as European Broadcast, is used, using a constellation of QPSK,

16QAM Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signal ...

, or 64QAM, enabling sufficient digital bandwidths at 6 MHz deviation for transmission of an MPEG transport stream at 10 or more megabits per second, producing three "lower", "center", and "upper" overlapping 6 MHz channels within each 12 MHz channel. BAS-2018

2 GHz relocation

In the United States between 2005 and 2010, the Federal Communications Commission (FCC) moved TV channels in the 2 GHz TV BAS band at the request of Sprint Nextel, so that it could use a portion which was adjacent to

PCS A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or techn ...

frequencies it already uses. The

report and order In administrative law, rulemaking is the process that executive and independent agencies use to create, or ''promulgate'', regulations. In general, legislatures first set broad policy mandates by passing statutes, then agencies create more det ...

resulting from this

rulemaking In administrative law, rulemaking is the process that executive and independent agencies use to create, or ''promulgate'', regulations. In general, legislatures first set broad policy mandates by passing statutes, then agencies create more deta ...

specified that Sprint/Nextel must pay for every TV station using the band to buy and install new BAS equipment to work in the new band structure. Previously, there had been seven analog TV channels, each 17 or 18 MHz wide, between 1990 and 2110 MHz. The new allocation created seven digital TV channels, each 12 MHz wide, from 2025.5 to 2109.5 MHz. (There was also a "narrowed in place" bandplan used as an interim measure, as the two bands overlap.)
Begun in 2005, the relocation was 94% complete as of October 2008, and was expected to be fully complete in mid 2009. After multiple extensions granted by the FCC, it was finally done in July 2010, with the completion of the

Anchorage Anchorage () is the largest city in the U.S. state of Alaska by population. With a population of 291,247 in 2020, it contains nearly 40% of the state's population. The Anchorage metropolitan area, which includes Anchorage and the neighboring Ma ...

, Alaska TV market. The cleared band is now used for PCS,

AWS Amazon Web Services, Inc. (AWS) is a subsidiary of Amazon that provides on-demand cloud computing platforms and APIs to individuals, companies, and governments, on a metered pay-as-you-go basis. These cloud computing web services provide di ...

, and MSS services, including

mobile broadband Mobile broadband is the marketing term for Wireless broadband, wireless Internet access via mobile networks. Access to the network can be made through a portable modem, wireless modem, or a Tablet computer, tablet/smartphone (possibly Tetherin ...

External links

''Broadcast Engineering'' article on completion''TV Technology'' article on completion, with insider details
{{bcast-stub Broadcast engineering