telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...

, 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, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whil ...

) 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 upp ...

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 telecommunication term typically used with mobile devices, such as mobile phones. It refers to a mobile phone being used outside the range of its native network and connecting to another available cell network. Technical ...

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 standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...

UMTS The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...

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-compatible ...

/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 Advanced Wireless Services (AWS) is a wireless telecommunications spectrum band used for mobile voice and data services, video, and messaging. AWS is used in the United States, Argentina, Canada, Colombia, Mexico, Chile, Paraguay, Peru, E ...

(AWS) 1700 MHz band is also seeing increased usage.

4G LTE bands

In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

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

TV broadcasting 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 wi ...

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 were forced to move to lower UHF and even far worse VHF frequencies with poorer

mobile TV Mobile television is television watched on a small handheld or mobile device. It includes service delivered via mobile phone networks, received free-to-air via terrestrial television stations, or via satellite broadcast. Regular broadcast stand ...

and even regular

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

performance, because the 700 MHz band has better

radio propagation Radio propagation is the behavior of radio waves as they travel, or are 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 waves are affecte ...

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 cell site, tower, any o ...

to penetrate deeper into buildings with less

attenuation In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable att ...

than the 1700 MHz or 2100 MHz bands.

AT&T Mobility AT&T Mobility LLC, also known as AT&T Wireless and marketed as simply AT&T, is an American telecommunications company. It is a wholly owned subsidiary of AT&T Inc. and provides wireless services in the United States. AT&T Mobility is the thi ...

devices use former

TV channel A television channel is a terrestrial frequency or virtual number over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the terrestrial or cable band of 54 to 60 MHz, with ...

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

Qualcomm Qualcomm () is an American multinational corporation headquartered in San Diego, California, and incorporated in Delaware. It creates semiconductors, software, and services related to wireless technology. It owns patents critical to the 5G, 4 ...

's defunct MediaFLO

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, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

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 through Providence, New Haven, Stamford, New York City, Philadelphia, Wilmington, a ...

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 divi ...

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), improper t ...

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

spectrum repacking A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...

occurs. The channel 52 spectrum was later purchased by

T-Mobile US T-Mobile US, Inc. is an American wireless network operator headquartered in Overland Park, Kansas and Bellevue, Washington, U.S. Its largest shareholder is a multinational telecommunications company Deutsche Telekom AG, which , holds 48.4 perc ...

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