Page 1028 - 5G Basics - Core Network Aspects

2 Transport aspects

Annex T

Dynamic time assignment (DTA) – higher-layer control aspects
(This annex forms an integral part of this Recommendation.)

Editorial note: This annex was introduced by Cor.3 to ITU-T G.9701, but is not shown in revision marks for
readability purposes.

T.1 Scope

This annex specifies the cross-layer control aspects of dynamic time assignment (DTA). According to
Annex X, the DRA block monitors traffic-related information and decides when to make changes in the TDD
frame configuration of each FTU-O. The update of the TDD frame configuration is done using the DTA
procedure described in clause X.6.2. This annex specifies the parameters to control the behaviour of the
DRA functionality that determines DTA. These parameters are individual to each line managed by the DRA.

T.2 DTA control parameters
The following DRA control parameters facilitate DTA operation:
• Annex X operation mode (Annex_X_mode);
• Allow DTA (DTA_allowed);

• Handshake Mds (hs_Mds)
• Preferred Mds for DTA (DTA_pref_Mds);
• Maximum step size for DTA changes (DTA_SMax);
• Minimum Mds for DTA (DTA_min_Mds);
• Maximum Mds for DTA (DTA_max_Mds);

• Minimum expected throughput for DTA (DTA_ETR_min);
• Maximum net data rate for DTA (DTA_NDR_max);
• Maximum net data rate (NDR_max);
• Minimum expected throughput (ETR_min)
The control parameter hs_Mds represents the Mds selected during the ITU-T G.994.1 handshake phase (see
Table 11.70.3 of ITU-T G.994.1) and provides the number of downstream symbol periods in a TDD frame
from the time the FTU-O enters showtime until the first DTA update. The control parameter hs_Mds is not
specific to the application of DTA but its definition is different if DTA is enabled (see clauses T.2.7, X.6.9 and
X.6.10).

The control parameters NDR_max and ETR_min are not specific to the application of DTA but their
definition is different if DTA is enabled (see clauses X.6.7.6 and X.6.7.7).

If DTA operation is disabled, these parameters shall be ignored.
T.2.1 Annex X operation mode (Annex_X_mode)

See clause X.6.7.1.

T.2.2 DTA allowed (DTA_allowed)
See clause X.6.7.2.

T.2.3 Preferred Mds for DTA (DTA_pref_Mds)
The control parameter DTA_pref_Mds represents the preferred Mds value and provides the number of
downstream symbol periods in a TDD frame requested by the DRA in a first DTA update after the FTU-O

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