This is the second-generation GSM Digital Unit for RBS 6xxx. It combines the baseband processing and back-haul interface of up to 12 TRX, in 1..6 logical BTSs.
- Table of contents
- DUG 20
- 48V DC supply power
- 70W maximal power consumption
- Size: 8U x 31mm x 250mm
- Weight: < 2kg
There is a CF slot on the left this device and it holds a 256mbyte CF card. The card contains a FAT filesystem with both the software as well as the configuration (IDB = Installatin DataBase).
The DUG 20 has 6 SFP slots for the interface towards the radio units, labelled RI A..F
The back-haul interface is Classic T1/E1/J1 (ISDN) based. The DUG has four T1/E1/J1 lines exposed as two RJ45 connectors ("ET A" and "ET B")
|1||A||RX tip (+)|
|2||A||RX ring (-)|
|3||B||TX tip (+)|
|4||A||TX tip (+)|
|5||A||TX ring (-)|
|6||B||TX ring (-)|
|7||B||RX tip (+)|
|8||B||RX ring (-)|
Same pinout as a Digium card with 2 lines per port.
So a cross-over cable is needed to connect to it.
note that its a bit smaller than the sfp slots
LMT B, LMT A, EC, GPS¶
LMT (Local Maintenance Terminal) A hosts a RS-232 port used for connecting to the DUG 20 from a PC running the OMT software.
Site-LAN and LMT B
"Enclosure Control". A (likely) RS-485 based site-local bus between different parts, particularly any power supply / climate systems and the digital unit. Used for monitoring/alamrs in case of environmental failure.
GPS¶This port is meant for attaching an external GPS receiver. The connector includes
- RS485/422 receiver for NMEA from the GPS
- RS485/422 transmitter for command to the GPS
- RS485/422 receiver for 1PPS signal from the GPS
- 12V power supply for the GPS
48V DC in¶
Connectory type is a https://www.te.com/usa-en/product-1982299-3.html with associated crimp contacts.
Connector on the Back¶
This connector is not used during normal operation. We assume it is for factory / service use only.