telecommunications Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...

, 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 A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...

) that supports multiple

radio frequency Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the u ...

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 Roaming is a wireless Wireless communication (or just wireless, when the context allows) is the transfer of information (''telecommunication'') between two or more points without the use of an electrical conductor, optical fiber or oth ...

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 The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and Mobile broadband modem, mobile broadba ...

UMTS The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses Wideband Code Division Multiple Access, wideband code-division multiple access (W-CDMA) radio access technolog ...

phones support all four bands, while most

CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatib ...

/1xRTT phones (mostly North America and voice transmission only) do not, and so are considered only dual-band devices. A few phones support both of the domestic frequencies but only one foreign one for limited

, making them tri-band phones. The term penta-band describes a device that supports a fifth frequency band, commonly the 1700/2100 MHz band in much of the world. The Advanced Wireless Services (AWS) 1700 MHz band is also seeing increased usage.

4G LTE bands

In the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

only, the two largest carriers are instead implementing 4G LTE in the 700 MHz band, which was reallocated from

TV broadcasting A television broadcaster or television network is a telecommunications network for the distribution of television content, where a central operation provides programming to many television stations, pay television providers or, in the United ...

during the

DTV transition The digital television transition, also called the digital switchover (DSO), the analogue switch/sign-off (ASO), the digital migration, or the analogue shutdown, is the process in which older analogue television broadcasting technology is conv ...

TV station A television station is a set of equipment managed by a business, organisation or other entity such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the earth's ...

s were forced to move to lower

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...

and even far worse VHF frequencies with poorer

mobile TV Mobile television is television watched on a small handheld or mobile device, typically developed for that purpose. It includes service delivered via mobile phone networks, received free-to-air via terrestrial television stations, or via satel ...

and even regular

terrestrial TV Terrestrial television, or over-the-air television (OTA) is a type of television broadcasting in which the content is transmitted via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an ant ...

performance, because the 700 MHz band has better

radio propagation Radio propagation is the behavior of radio waves as they travel, or are wave propagation, propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio w ...

characteristics that allow

mobile phone signal A mobile phone signal (also known as reception and service) is the signal strength (measured in dBm) received by a mobile phone from a cellular network (on the downlink). Depending on various factors, such as proximity to a tower, any obstructio ...

to penetrate deeper into buildings with less

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 ...

than the 1700 MHz or 2100 MHz bands.

AT&T Mobility AT&T Mobility, LLC, also known as AT&T Wireless and Trade name, marketed as simply AT&T, is an American telecommunications company. Formed in April 2000 as Cingular Wireless LLC, It is a wholly owned subsidiary of AT&T, AT&T Inc. and provide ...

devices use former TV channel 53 and 54 nationwide and has purchased spectrum from former TV channel 55 nationwide (purchased from

Qualcomm Qualcomm Incorporated () is an American multinational corporation headquartered in San Diego, California, and Delaware General Corporation Law, incorporated in Delaware. It creates semiconductors, software and services related to wireless techn ...

's defunct

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 ...

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, b ...

service), and also channel 56 in densely populated areas such as

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 ...

and the

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, Rhod ...

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 div ...

formerly held frequencies just above TV channel 51, which is still in use, causing

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), improp ...

that is preventing the carrier from using them until the planned top-down

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 col ...

occurs. The channel 52 spectrum was later purchased by

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 carrie ...

who now uses this spectrum for their network. Verizon now uses higher blocks within the former TV band (channels 60 and 61).

References

{{Mobile phones GSM standard Mobile technology

4G LTE bands

See also

References