B28 (700 MHz)

The 3GPP LTE Band 28, referred to as APT 700, operates within the 700 MHz spectrum following the Asia-Pacific Telecommunity (APT) band plan. This frequency range was made available for mobile services after the transition from analogue to digital television, commonly referred to as the "digital dividend". Benefitting from its sub-1 GHz positioning, Band 28 offers excellent propagation characteristics and wide channel widths, ensuring wide area coverage and strong indoor penetration. Its technical advantages, coupled with the harmonised band plan, have contributed to its widespread adoption across various regions, making it one of the most universally utilised bands for LTE deployments.

B28 band is an LTE frequency division duplexing (FDD) band split into 703 to 748 MHz / 758 to 803 MHz. In some applications the B28 band is implemented as B28A (703 to 733 MHz / 758 to 788 MHz) and B28B (718 to 748 MHz / 773-803 MHz). Each of the B28A and B28B bands is typically provided with its own duplexer due to, for example, challenges associated with bandwidth and duplex gap.

700 MHz LTE has been a popular choice due to availability of digital-dividend spectrum, and unmatched propagation characteristics permitting wide area coverage in regional and rural environments, and excellent in-building coverage. Due to its large wavelength, B28 does not easily support Massive MIMO and beamforming technologies.

Notably, B28 cannot be deployed as a standalone 1.4 MHz LTE-M network, instead LTE-M must be deployed in-band.