DUG 20 » History » Revision 11
Revision 10 (laforge, 08/09/2020 02:55 PM) → Revision 11/16 (tnt, 10/09/2020 09:37 AM)
h1. 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.
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h2. Technical data
* 48V DC supply power
* 70W maximal power consumption
* Size: 8U x 31mm x 250mm
* Weight: < 2kg
h2. 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).
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h2. Connections
h3. Front Haul
The DUG 20 has 6 SFP slots for the interface towards the radio units, labelled RI A..F
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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).
h3. 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")
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Pinout: FIXME
|_.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.
h3. ESB port
note that its a bit smaller than the sfp slots
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h3. LMT B, LMT A, EC, GPS
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h3. 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|
h3. LMT B
Site-LAN and LMT B
FIXME
h3. 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.
h3. 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
h3. 48V DC in
Connectory type is a https://www.te.com/usa-en/product-1982299-3.html with associated crimp contacts.
{{thumbnail(DUG20_01_DC_in_detail.jpg, size=400)}}
h3. Connector on the Back
This connector is not used during normal operation. We assume it is for factory / service use only.
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h2. LEDs
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h2. Overview Pictures
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