DUG 20¶

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.

The DUG 20 is only compatible with the RUS and RRUS radio units, not with the older RUG units.

• Table of contents
• DUG 20
  • Technical data
  • Flash
  • Connections
    • Front Haul
    • Back-Haul interface
    • ESB port
    • LMT B, LMT A, EC, GPS
    • LMT A
    • LMT B
    • EC
    • GPS
    • 48V DC in
    • Connector on the Back
  • LEDs
  • Overview Pictures

Technical data¶

• 48V DC supply power
• 70W maximal power consumption
• Size: 8U x 31mm x 250mm
• Weight: < 2kg

Flash¶

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).

Connections¶

Front Haul¶

The DUG 20 has 6 SFP slots for the interface towards the radio units, labelled RI A..F

This is where you connect your RUS or RRUS, either via direct-attach cables (usual for RUS), or via SFP transceivers and optical fiber (usual for RRUS).

Back-Haul interface¶

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")

Pinout:

RJ45	Line	Signal
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.

ESB port¶

note that its a bit smaller than the sfp slots

LMT B, LMT A, EC, GPS¶

LMT A¶

LMT (Local Maintenance Terminal) A hosts a RS-232 port used for connecting to the DUG 20 from a PC running the OMT software.

RJ45	DB-9 (female)	Signal
1	5	GND
2	3	TxD
3	2	RxD

LMT B¶

Site-LAN and LMT B

FIXME

EC¶

"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.

LEDs¶

Overview Pictures¶