PEF24901HV22XT Lantiq, PEF24901HV22XT Datasheet - Page 51

• Manufacturer Part Number: PEF24901HV22XT
• Manufacturer: Lantiq

Specifications of PEF24901HV22XT

• Control Interface: HDLC
• Lead Free Status / Rohs Status: Compliant

Significance of the 4B3T Signal Elements
Table 12
reference point in the course of an activation or deactivation process.
Table 12
U0
U1W
U2W
U2
U1A
U1
U3
Data Sheet
lists the defined 4B3T signal elements that are exchanged across the U-
No signal or deactivation signal that is used in both directions.
Downstream, it requests the NT to deactivate. Upstream, the NT
acknowledges by U0 that it is deactivated.
Awake or awake acknowledge signal upstream (7.5 kHz) used in the
awake procedure of the U-interface.
Awake or awake acknowledge signal downstream (7.5 kHz) used in the
awake procedure of the U-interface.
The LT sends U2 to enable the own echo canceller to adapt the
coefficients. By the Barker code the NT at the other end is enabled to
synchronize. The detection of U2 is used by the NT as a criterion for
synchronization.
The M-channel on U may be used to transfer loop commands.
U1A is similar to U1 but without framing information. While the NT
synchronizes on the received signal, it sends out U1A to enable its echo
canceller to adapt its coefficients, but sends no Barker code to prevent the
LT from synchronizing on the still asynchronous signal. Due to proceeding
synchronization, the U-frame may jump from time to time. U1A can not be
detected by the far-end LT.
When synchronized, the NT sends the Barker code and the LT may
synchronize itself. U1 indicates additionally that a terminal equipment has
not yet activated. Upon receiving U1 the LT indicates the synchronized
state by C/I ’UAI’ to layer-2.
Usually during activation, no U1 signal is detected in the LT because the
TE is activated first and U1 changes to U3 before being detected.
The M-channel on U may be used to transfer code error indications.
U3 indicates that the whole link to the TE is synchronous in both directions.
On detecting U3 the LT requests the NT by U4H to establish a fully
transparent connection.
The M-channel on U may be used to transfer code error indications.
4B3T Signal Elements
52
Functional Description
PEF 24901
2002-09-30
DFE-T