Reference Manual

Product Description 15 (33)
SRN/X-00:146 Rev B 2001-05-16 © Ericsson. Commercial in confidence
3.9 Transmission
All RBS 2000 models support multi-drop bypass functionality. Each RBS can be
configured for stand alone or linear cascade mode. The configuration is performed by
means of the OMT.
LAPD concentration and LAPD multiplexing could be used to make the transmission
resource more efficient.
The DXU-21 is equipped with four external ports supporting in total up to 8 Mbit/s.
Interfaces
• T1/1.5 Mbit/s, 100 Ohm
• E1 2 Mbit/s, 75 Ohm
• E1 2 Mbit/s, 120 Ohm
The interfaces are supported on the same physical ports.
Connections
E1/75, E1/120 and T1/100 Ohm is connected to the RBS 2106 via a screw terminal that
includes an impedance converter.
E1/120 Ohm and T1/100 Ohm transmission supports Long Haul. E1/G.703 and T1/DS1
offer multi vendor compatibility on the transmission level. Normally E1/G.703 and
T1/DS1 only offers short haul interfaces, enabling distances up to 6 dB loss. The long haul
feature allows for 30 dB loss and a more cost efficient transmission network
configuration.
75 Ohm is only available for E1 operation and does not support long haul. The distance
allowed between units is determined by the cable loss, according to the 6 dB receiver
sensitivity specified in G.703.
Additional transmission equipment and TM box
The RBS 2106 cabinet has got room for additional transmission equipment in the Optional
Expansion Unit (OXU) positions above the dTRU.
The RBS 2106 supports the possibility of housing Mini-DXC or DXX equipment in the
OXU positions in the PSU sub rack.
The 2-card DXX plug-in unit for RBS 2106 is a Digital cross-connect with four G.704
ports and one slot for 2-4 additional interfaces that can be G.703, HDSL, LTE or Optical
fibre.
The 1 card DXX plug-in unit for RBS 2106 is a Digital cross-connect with four G.703
ports.
The Mini-DXC plug-in unit for RBS 2106 is a Digital cross-connect with five G.703
ports.