User's Manual

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DESCRIPTION 9 ( 25 )

ERA/RGN/PD Jennie Bergström 5/1551-HRB 105 102/1 Uen

ERA/RKF/TU Carl Helander 2003-01-28 C

Prepared (also subject responsible if other) No

Approved Checked Date Rev Reference

RAXBs within a BB subrack share the load to achieve high availability. If one

RAXB fails, the load is divided over the remaining RAXBs. This ensures the

RBS continues to handle traffic, although with reduced capacity.

4.3.4 GPB

The General Processor Board (GPB) operates as an MP; it contains and

executes the main part of the RBS software. The GPB controls devices on

boards and in auxiliary units, it has flash disk storage, an Ethernet connection

and an RS232 interface.

The GPB can be duplicated to provide redundancy, in case of failure in the

active MP, the other GPB can be started and take over as MP.

4.3.5 TXB

The Transmitter Board (TXB) comprises the BB transmitter part for:

• handling transport channels,

• encoding,

• cell splitting,

• modulation and spreading,

• and channel combining.

4.3.6 TUB

The Timing Unit Board (TUB) generates and distributes reference signal for

local timing generation. The frequency accuracy is given by an external

reference signal either provided on a transmission interface or local external

source. The reference signal must be traceable to clock having the equality of

Stratum 2 (ITU-T G.812) or better.

The TUB can be duplicated to provide redundancy. Due to close relationship

with the SCB, the TUB and SCB must be duplicated simultaneously.

4.3.7 BBIFB

The Baseband Interface Board (BBIFB) connects the BB subrack to the RF

subrack. The connection carries the downlink and uplink traffic streams as

well as timing signals.

4.4 RF Subrack

The RF subrack contains most of the RF processing hardware (it does not

contain the power amplifiers and optional ASC (Antenna System Control).

The RF subrack takes care of: