User's Manual

Open Information
DESCRIPTION 7 ( 20 )
EAB/RWB/ZG Christina Wilson 18/1551–HRB 105 102/1 Uen
EAB/RWB/Z (Dennis Radenholt) 2003-06-16 B
Prepared (also subject responsible if other) No
Approved Checked Date Rev Reference
E
within the subrack. The subrack’s BB and RF parts are connected to each other
through the BB Interface Board (BBIFB) and the RF Interface Board (RFIFB)
carrying the downlink and uplink traffic streams.
The BB/RF subrack comprises an Iub interface connection with an RNC, the
MP cluster, and the baseband and radio frequency functionality.
Baseband functionality consists of:
• Encoding and decoding of transport channels
• Spreading of bits
• Combining of channels
• Reception through a rake receiver
• Searching and random access processing
The RF part contains all the RF processing hardware, except for the power
amplifiers. It takes care of:
• D/A and A/D conversion
• RF modulation and demodulation
• RF carrier combining and splitting
• Low noise amplification for reception
The following sections give a brief description of the boards in the subrack.
4.1.1 Baseband Boards
ETB
The Exchange Terminal Board (ETB) provides the connections for the Iub and
remote Mub interfaces. It serves as an interface between the transmission
cables and the Asynchronous Transfer Mode (ATM) switch on an SCB. The
type of ETB(s) depends on the transmission standard.
SCB
The Switch Core Board (SCB) contains an ATM switch and interfaces to the
ATM switch ports located on other boards via the backplane.
The SCB also has a connector and filter for the system power. The system
power is distributed within the subrack via the backplane.
RAXB
The Random Access/Receiver Board (RAXB) comprises the baseband receiver
part, which takes care of decoding, searching and rake receiving for dedicated
and random access transport channels, and cell combining for softer handover.