ABB REB670 Applications Manual page 495

1MRK 505 337-UUS -
19.4
Application manual
Sample specification of communication requirements
for the protection and control terminals in digital
telecommunication networks
The communication requirements are based on echo timing.
Bit Error Rate (BER) according to ITU-T G.821, G.826 and G.828
•
-6
<10 according to the standard for data and voice transfer
Bit Error Rate (BER) for high availability of the differential protection
• -8 -9
<10 -10 during normal operation
• -6
<10 during disturbed operation
During disturbed conditions, the trip security function in can cope with high bit error rates
-5
up to 10 or even up to 10
COMFAIL from the differential protection communication supervision, or blocked when
COMFAIL is issued after receive error >100ms. (Default).
Synchronization in SDH systems with G.703 E1 or IEEE C37.94
The G.703 E1, 2 Mbit shall be set according to ITU-T G.803, G.810-13
• One master clock for the actual network
• The actual port Synchronized to the SDH system clock at 2048 kbit
• Synchronization; bit synchronized, synchronized mapping
• Maximum clock deviation <±50 ppm nominal, <±100 ppm operational
• Jitter and Wander according to ITU-T G.823 and G.825
• Buffer memory <250 μs, <100 μs asymmetric difference
• Format.G 704 frame, structured etc.Format.
• No CRC-check
Synchronization in PDH systems connected to SDH systems
• Independent synchronization, asynchronous mapping
• The actual SDH port must be set to allow transmission of the master clock from the
PDH-system via the SDH-system in transparent mode.
• Maximum clock deviation <±50 ppm nominal, <±100 ppm operational
• Jitter and Wander according to ITU-T G.823 and G.825
• Buffer memory <100 μs
-4
. The trip security can be configured to be independent of
Section 19
Requirements
489