Asia-Pacific Telecommunity band plan
The Asia-Pacific Telecommunity (APT) band plan is a type of segmentation of the 612–806 MHz band (usually referred to as the 600 MHz & 700 MHz bands) formalized by the APT in 2022–2023 and 2008-2010 respectively and specially configured for the deployment of mobile broadband technologies (e.g. most notably Long Term Evolution, LTE). This segmentation exists in two variants, FDD and TDD, that have been standardized by the 3rd Generation Partnership Project (3GPP) and recommended by the International Telecommunication Union (ITU) as segmentations A5 and A6, respectively. The APT band plan has been designed to enable the most efficient use of available spectrum. Therefore, this plan divides the band into contiguous blocks of frequencies that are as large as possible taking account of the need to avoid interference with services in other frequency bands. As the result, the TDD option (segmentation A6) includes 100 MHz of continuous spectrum, while the FDD option (segmentation A5) comprises two large blocks, one of 45 MHz for uplink transmission (mobile to network) in the lower part of the band and the other also of 45 MHz for downlink transmission in the upper part. As defined in the standard, both FDD and TDD schemes for the 700 MHz band include guard bands of 5 MHz and 3 MHz at their lower and upper edges, respectively. The FDD version also includes a centre gap of 10 MHz. The guard bands serve the purpose of mitigating interference with adjacent bands while the FDD centre gap is required to avoid interference between uplink and downlink transmissions. The two arrangements are shown graphically in figures 1 and 2.
Existing 3GPP standards for the APT band plan are given below:
| 3GPP LTE band | 3GPP NR band | Duplex | Uplink Frequency | Downlink frequency |
|---|---|---|---|---|
| 28 | n28 | FDD | 703–748 MHz | 758–803 MHz |
| 44 | - | TDD | 703–803 MHz | 703–803 MHz |
| - | n105 | FDD | 663–703 MHz | 612–652 MHz |
Table 1. 3GPP standard bands for the APT segmentation of the 600 and 700 MHz bands
Allocation of the 700 MHz band (that in many parts of the world is commonly referred to as the Digital Dividend) to mobile communications it is one of the key solutions for meeting the mobile data explosion challenge faced by the telecommunications industry and telecommunications regulators seeking additional spectrum for the deployment of new mobile broadband networks and capacity. As of today, the APT band plan is considered to be the most effective way to segment the 700 MHz band from the point of view of modern spectrum management. The superior spectral efficiency of this plan is explained further in this article. Currently, the FDD configuration is the one which has been studied most widely and is much more popular across the world. For this reason, the FDD APT band plan option is generally referred to as the APT band plan.