DUL 20¶

DUL is a Digital Unit for LTE. It contains the eNodeB function down to the baseband processing.

• Table of contents
• DUL 20
  • Connectors
    • PWR
    • GPS (RJ45)
    • EC (RJ45)
    • AUX (RJ45)
    • LMT A (RJ45)
    • LMT B (RJ45)
    • TN A (RJ45)
    • TN B (SFP)
    • IDL (HSIO)
    • RI A..F (SFP)
  • Overview Pictures
  • Accessing it
    • SSH via LMT-B

Connectors¶

PWR¶

48V DC connector. The negative rail is towards the edge of the unit. Also seems to power up fine at 36V

GPS (RJ45)¶

Connection for an Ericsson GPS module, contains 1PPS and UART signals

EC (RJ45)¶

Environment Control? Probably some RS-485 to control fans, power management, UPS, ...

AUX (RJ45)¶

?

LMT A (RJ45)¶

A RS-232 on RJ45 for Local Maintenane use. IT provides access to COLI (COmmand LIne).

The pinout is shown below. Please note it is different from RBS3000!

RJ45	DB9	Name
1	5	GND
2	3	TXD (of PC)
3	2	RXD (of PC)

The [default?] baud rate settings are 9600 8N1

LMT B (RJ45)¶

Site LAN Ethernet, for adminstrative purpose

TN A (RJ45)¶

Transmission Ethernet, i.e. the back-haul interface for S1. RJ-45

TN B (SFP)¶

Transmission Ethernet for optical back-haul. Can use normal SFP modules.

IDL (HSIO)¶

Inter-DU-Link for cross-connecting multiple DU.

RI A..F (SFP)¶

Radio Interface (CPRI) using either SFP transceivers for RRU connection or copper interconnect cables for RU.

Overview Pictures¶

Accessing it¶

SSH via LMT-B¶

It appears the DUL will always respond to 169.254.1.10/16, no matter what kind of real/other IP address has been set.

You have to use the following SSH config to speak the ancient cipher/key-exchange:

Host dul
        HostName 169.254.1.10
        KexAlgorithms diffie-hellman-group1-sha1
        Ciphers 3des-cbc

and then log in as the 'rbs' user with 'rbs' password.