2 Digital subscriber line VDSL2
2.10 Frequency plans for symmetrical data transfers

Usage of symmetrical data transfers is especially developed for small and medium-sized companies whose employees need data from the Internet not only download but also quickly upload. An example of service with symmetric transmission speeds may be more popular video, which was organized instead of conventional workshops.

It was noted in the previous chapter that it determined for symmetrical data transfer the fundamental frequency plan 997. This plan is further divided into next parts:

- 997 - fundamental frequency plan with the usual alternating bands for the downstream and upstream connections taken from VDSL,
- 997E - frequency plan with the usual alternating bands for the downstream and upstream extended to 17 MHz to 30 MHz, respectively,
- HPE - special frequency plan for the working connections between 7,05 MHz and 30 MHz (sections 17a, 30a).

Example of 997E frequency plan parameters for each profile VDSL2 connections in Europe.
VDSL2 profiles | The highest utilized subchannel | Upper limit frequency for downstream [MHz] | Upper limit frequency for upstream [MHz]
8a | 2047 | 7,05 | 8,832
8b | 2047 | 7,05 | 8,832
8c | 1182 | 7,05 | 5,1
8d | 2047 | 7,05 | 8,832
12a | 2782 | 7,06 | 12
12b | 2782 | 7,05 | 12
17a | 4095 | 14 | 17,664
30a | 3478 | 27 | 30

Substitution each band in frequency plans for symmetrical data transfers.