In telecommunications, the terms multi-band, dual-band, tri-band, quad-band and penta-band refer to a device (especially a mobile phone) supporting multiple radio frequency bands

Frequency

Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

  used for communication. In the mobile case, the purpose of doing so is to support roaming

Roaming

In wireless telecommunications, roaming is a general term referring to the extension of connectivity service in a location that is different from the home location where the service was registered. Roaming ensures that the wireless device is kept connected to the network, without losing the...

 between different countries/regions whose infrastructure cannot support mobile services in the same frequency range.

See also

• List of UMTS networks around the world, and the frequencies and data rates they support
• GSM frequency bands, as defined by the standards bodies
• UMTS frequency bands
  UMTS frequency bands
  The UMTS frequency bands are radio frequencies used by third generation wireless Universal Mobile Telecommunications System networks.They were allocated by delegates to the World Administrative Radio Conference held in Málaga-Torremolinos, Spain between February 3, 1992 and March 3, 1992...
  
  , as defined by the standards bodies