Ericsson MOBITEX BRU3 User manual

Contents
1 General ........................................................................................................3
2 Hardware Units............................................................................................4
3 Hardware Modules ......................................................................................6
3.1 Logic and Modem Equipment..........................................................6
3.2 Radio Unit Modules.........................................................................7
3.3 Power Supply Equipment.................................................................7
4 Modem Equipment......................................................................................8
4.1 Telephone Modem Boards.............................................................10
4.1.1 V.11 and V.28 Serial Interfaces..........................................10
4.1.2 Interface signals..................................................................11
4.1.3 Connector............................................................................12
5 Logic Equipment ....................................................................................... 13
5.1 Synchronous Serial Circuit ............................................................ 14
5.2 Main CPU including Memory........................................................14
5.3 Dual Port Memory..........................................................................14
5.4 Signal Processor Unit with Memory..............................................15
5.5 Console Ports .................................................................................15
5.6 LEDs ..............................................................................................15
5.7 Reset Button...................................................................................16
6 Radio System.............................................................................................17
6.1 Radio Parameters ...........................................................................18
6.1.1 Frequency Band 400 MHz (HRB 104 43/xx).....................18
6.1.2 Frequency Band 800 MHz (HRB 104 43/C20) .................. 19
6.1.3 Frequency Band 900 MHz (HRB 104 43/C2, C4, C5, C6) 19
6.1.4 Frequency Band 900 MHz (HRB 104 43/C7, C8).............. 20
6.2 Radio Units.....................................................................................21
6.2.1 Transmitter..........................................................................21
6.2.2 Modulation Synthesizer......................................................22
6.2.3 Receiver .............................................................................. 22
6.2.4 Reference Oscillator ...........................................................22
BRU3 Logic and Radio
System
BRU3 MANUAL, Doc.no: 155 16-ANNA 805 08 Uen, Rev H, 2003-02-07

BRU3 MANUAL
BRU3 MANUAL, Doc.no: 155 16-ANNA 805 08 Uen, Rev H, 2003-02-07
The contents of this document are subject to revision without notice due to continued progress in methodology,
design and manufacturing.
Ericsson shall have no liability for any errors or damages of any kind resulting from the use of this document.
6.2.5 Radio Control Circuit ..........................................................23
6.2.6 Filter ....................................................................................23
7 Power Supply Equipment...........................................................................24
7.1 Power Supply Unit..........................................................................25
7.1.1 AC/DC Module ...................................................................25
7.1.2 DC/DC Module ...................................................................25
7.1.3 Battery Charge.....................................................................26
7.1.4 DC Alarms...........................................................................26
7.1.5 Lightning Protection............................................................26
7.1.6 Connectors...........................................................................26
7.1.7 Switches...............................................................................26
7.1.8 LEDs....................................................................................27
7.1.9 Fuses....................................................................................27
7.2 Battery Unit.....................................................................................27
8 Heating unit................................................................................................28
9 BRU3 Connections.....................................................................................29
9.1 I/O CONNECTIONS......................................................................31
10 Software Description..................................................................................32
10.1 PREBOOT FE.................................................................................32
10.2 BOOT FE........................................................................................33
10.3 MAIN FE........................................................................................33
10.4 FBTEST..........................................................................................33

BRU3 LOGIC AND RADIO SYSTEM 3 (34)
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1 General
The Base Radio Unit 3 (BRU3) is a complete one-channel radio base station
which uses 8 kbps data signalling and is designed for the 400, 800 and 900 MHz
frequency band. The BRU3, which may be installed outdoors and indoors, is a
link between the mobile terminals (MOB) and the area exchanges (MOX) in the
Mobitex Network.
The BRU3 includes main computer, internal power supply, internal heating,
alarm handling, radio modem, radio transceiver, radio filters and I/O
connections. Optional line modem and battery unit may be included.

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2 Hardware Units
The BRU3 consists of two main mechanical parts:
The FBF comprises:
The FTF is hinged to the bottom part and works as a cover as well as a cooling
flange, offering good thermal management for the BRU3. The FTF comprises:
FE Case Bottom Frame FBF (1)
FE Case Top Frame FTF (5)
Weather-protected throughputs for
the cabling
FE Connection Board FNB (11)
FE Power Supply Unit FPU (2)
FE Battery Unit, for power supply backup FBU (3)
FE Adaptation Board FAB (4)
FE Computer Board FCB (6)
FE Modem Board FMB (7)
FE Radio Board FRB (8)
FE Filter Module FFM (9)
FE Heating Unit FHU (10)

BRU3 LOGIC AND RADIO SYSTEM 5 (34)
BRU3 MANUAL, Doc.no: 155 16-ANNA 805 08 Uen, Rev H, 2003-02-07
Figure 1 Base Radio Unit (BRU3).

6 (34) BRU3 MANUAL
BRU3 MANUAL, Doc.no: 155 16-ANNA 805 08 Uen, Rev H, 2003-02-07
3 Hardware Modules
The BRU3 hardware is shown in Figure 1 “Base Radio Unit (BRU3).”. The
BRU3 Logic and Modem Equipment, Radio System and the Power Supply
Equipment are housed in one single cabinet. The following subsections briefly
describe the modules that are directly involved in the traffic flow and signal
processing to be outlined below. Other hardware is described further on in this
section.
3.1 Logic and Modem Equipment
The Logic and Modem Equipment contains the following boards:
Figure 2 Hardware modules.
FCB FE Computer Board
FMB FE Modem Board
FAB FE Adaptation Board
LINE
INTER
FACE
COMPUTER
PART RADIO
PART
POWER
SUPPLY
UNIT
MOX
Port
Console Port
1/LZEA 801 350 R1

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3.2 Radio Unit Modules
The BRU3 Radio Units contains the following boards:
3.3 Power Supply Equipment
FRB FE Radio Board
FFM FE Filter Module
FPU FE Power Supply Unit
FBU FE Battery Unit
FHU FE Heating Unit
FHB FE Heating Board
FHE FE Heating Element

8 (34) BRU3 MANUAL
BRU3 MANUAL, Doc.no: 155 16-ANNA 805 08 Uen, Rev H, 2003-02-07
4 Modem Equipment
There are three alternative line interfaces for connection to a MOX:
• telephone modem V.32
• balanced serial interface V.24/V.11 (RS422)
• unbalanced serial interface V.24/V.28 (RS232)
Figure 3 Line interface block diagram.
V24/V28
V24/V11
DAA
Adaptation
Board
Console/
Boot Source
Select
9
16
2+4
2+3
Boot Source Select
Console
To Modem
Select V11
Select V24
Select V28
25 pol
D-sub
9 pol
D-sub
9 pol
D-sub
8/LZEA 801 350
Filter and OVP

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The choice between telephone modem, balanced serial interface and
unbalanced serial interface, is made by setting Switch 2 (SW2) as follows. To
locate Switch 2, please refer to FE Computer Board - FCB in the BRU3
Mechanical Design section.
Data communication between a base station and an area exchange (MOX) is
using data connections with a X.25 protocol.
X.25 protocol can use either a leased line or a packet switched data network.
Switch 2
SW2:1 SW2:2 SW2:3 Comments
Open or closed Open Open V.32bis
Open Open Closed V.28 (RS232)
Closed Open Closed V.11 (RS422)
Other alternatives not allowed.
SW2:4 Comments
Open OEM Strap

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4.1 Telephone Modem Boards
The telephone modem, which supports the CCITT V.32 and V.32bis standards,
consists of two separate boards, the FE Modem Board V.32 (FMB) and the FE
Adaptation Board (FAB). Depending on national requirements issued by the
telecommunications administration in your country, different versions of the
FAB may be used. Also, depending on the BRU3 variant, the telephone modem
may not be installed.
Two-wire leased, four-wire leased or switched lines are used for data
transmission. The maximum transmission rate is 14 400 bits/sec. The modem is
connected to the computer part via a synchronous serial circuit.
Asynchronously transferred AT/Hayes commands are used for modem
configuration and control.
The software used by the modem is installed from the main processor and stored
in a memory.
The FMB does not include a reset button. To reset the FMB and FAB, a power
off-operation is necessary.
4.1.1 V.11 and V.28 Serial Interfaces
The FE Connection board (FNB) includes conversion circuits for V.11 and V.28
standards for the serial interfaces. It also includes voltage protection and filters
for the modem, the V.11, the V.28 and the console ports.

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4.1.2 Interface signals
The following table shows the signals included in the interface. The same
signals appear both for V.11 and V.28.
I/O
Signal CCITT V.24 Circuit No. Description
GND 101 Protective Ground
SG 102 Signal Ground
TD 103 Transmit Data
RD 104 Receive Data
RTS 105 Request to Send
DTR 108 Data Terminal Ready
DCD 109 Data Carrier Detect
ETC 113 External Transmit Clock
TC 114 Transmit Clock
RC 115 Receive Clock

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4.1.3 Connector
A 25p d-sub connector is used for both V.11 and V.28. The following table
shows the signals used:
Pin Connector P4 V.28
(RS232) Connector P5 V.11 (RS422)
1 Protective Ground (101) Protective Ground (101)
2 TD (103) TD- (103)
3 RD (104) RD- (104)
4 RTS (105) RTS- (105)
5- -
6- -
7 GND (102) GND (102)
8 DCD (109) DCD- (109)
9 - DCD+ (109)
10 - -
11 - TD+ (103)
12 - RD+ (104)
13 - RTS+ (105)
14 - TC+ (114)
15 TC (114) TC- (114)
16 - -
17 RC (115) RC- (115)
18 - -
19 - RC+ (115)
20 - -
21 - -
22 - -
23 - ETC+ (113)
24 ETC (113) ETC- (113)
25 - -

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5 Logic Equipment
The FE Computer Board (FCB) contains the main computer block which
consists of:
• Synchronous serial circuit
• Main CPU including memory
• Memory for main CPU
• Dual port memory
• Signal processor unit (SPU) with memory
• Console ports
• LEDs for Watchdog alarm and status indication
• Reset button
• Switch 2 (SW2) for setting line interface alternative.
Figure 4 MAIN computer block diagram.
CPU68030
19.2MHz DRAM FLASH Watchdog TIMER
Serial
I/O Parallel
I/O Temp.
Sensor Dual Port
Memory OTTAWA
19.2MHz
SRAM
64Kb DSP Radio
Interface
FNB FMB FPU
2/LZE 401 02 R2

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5.1 Synchronous Serial Circuit
An integrated circuit, Z16C35, is used as a synchronous serial circuit with
Direct Memory Access (DMA). The integrated circuit contains two serial ports.
Communication drivers are available in the Mobitex SW.
5.2 Main CPU including Memory
The main CPU consists of a MC68EC030-25RP running at 19.2 MHz.
The DRAM is used for data storage and program execution. The Flash PROM
is used to store the system software. There is also a Boot Flash-PROM. The
program file for this area is loaded to the Flash-PROM via the console port
using a VT100-compatible portable PC. (For more information, please refer to
SoftwareCommissioning Procedure in the Commissioning Procedure section of
the BRU3 - General module.)
There are no EPROM, EEPROM or SRAM for the main CPU.
The main CPU also comprises the following functionalities:
• Watchdog
• Parallel inputs for alarms.
• Parallel outputs for LEDs and other controls.
• Clock-tick generator, fed by the reference oscillator.
5.3 Dual Port Memory
The dual port memory transfers data between the main CPU and the Signal
processing unit (SPU). The size is 2Kbit * 16. The memory is implemented in
a dual port memory chip.

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5.4 Signal Processor Unit with Memory
The TMS320C25 Signal processor unit is used for modulation, demodulation
and radio control. The SPU contains an 8 kbit * 16 SRAM with 25 ns access
time. No EPROM or FLASH is included. The BOOT program is loaded to the
dual port memory by the main CPU.
5.5 Console Ports
The FCB contains two ports for serial communication, both handled by the
integrated circuit Z16C35.
Port A implies complete synchronous functionality, and also, limited modem
support. By the FNB and FMB, this port can be used for V.24/V.28, V.24/V.11
or V.24/V.32.
Port B is intended for the use of a console via the FNB with the V.24 signals,
RX and TX.
5.6 LEDs
LED Colour Function
Status indicator Yellow Lit when the processor is operating OK.
Watchdog alarm Red Lit when the Watchdog is released. If so, a reset
pulse is generated. The Watchdog LED is lit and the
signal WDSTATUS, read by the CPU, peaks.

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5.7 Reset Button
To enable a hardware reset of the FCB and the FMB (Modem Board), and also,
the FRB (FE Radio Board), the FCB is equipped with a reset button located next
to the LED Status indicator. To reach the button for a reset operation, use a long
and narrow, non-conductive object (pen or similar). A reset of the FCB may be
generated for the following reasons:
1. Power-on reset: The reset is generated at power-on, and also, when a
power drop occurs.
2. Switch reset: The reset is activated when the reset button is pressed.
3. Watchdog reset. The reset is activated by the watchdog function if not
maintained.
4. CPU reset: The reset is performed by the CPU when a reset instruction is
executed. In this specific case, no reset of the CPU itself is carried out.

BRU3 LOGIC AND RADIO SYSTEM 17 (34)
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6 Radio System
Figure 5 Radio system block diagram.
LNA Amp Amp Amp
3 pole Mixer Mixer Mixer
X-tal filter 450 kHz
VCO
Synth ic Filter FilterBuffer
Rx Synthe izer
Interface Logic/Radio SDATA SCLK SSTBTX SSTBRX SSTBMOD REFCLK A8-A0 D7-D0 READ WRITE SEL0 SEL1 ADRDY MODSIG MODSTB
Helena Ic
O c cont
Temp
Di c
Ri
Pr
Pf
Tx on
Tx power
Mod VCO
Mod toxc
OCXO
1/2
x6 1/26
Synth Ic
Synth Ic
Filter Filter
DET
DET
DET
OP-amp
TCXO
VCO
Buffer Buffer I olator
Power Control
Power Amp
Directional Coupler
Duplex filter
492 kHz78.8 MHz
R i
READ WRITE EN VBAT
Memory
818-824 MHz
Tran mitter
77.25 MHz
42 kHz
38.4 MHz
TX Synthe izer
Antenna
12.8 MHz
Pr
Pf
11/LZEA 801 350 R3

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6.1 Radio Parameters
6.1.1 Frequency Band 400 MHz (HRB 104 43/xx)
For a list of all Product Numbers, please refer to the Introduction and Product
Specification section in the BRU3 - General module.
Radio data transmission rate 8 kbps
Modulation modified GMSK
Traffic mode duplex
Channel bandwidth 12.5 kHz
Sensitivity -117 dBm at 1% BER
Frequency range Tx: within the 400 MHz range.
Rx: within the 400 MHz range.
Frequency stability ±0.2 ppm
Antenna output
power 6 W Duplex filter
6 W TxBP filter
Antenna impedance 50 ohms

BRU3 LOGIC AND RADIO SYSTEM 19 (34)
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6.1.2 Frequency Band 800 MHz (HRB 104 43/C20)
For a list of all Product Numbers, please refer to the Introduction and Product
Specification section in the BRU3 - General module.
6.1.3 Frequency Band 900 MHz (HRB 104 43/C2, C4, C5, C6)
For a list of all Product Numbers, please refer to the Introduction and Product
Specification section in the BRU3 - General module.
Frequency range Tx: 864.0 - 870.0 MHz
Rx: 819.0 - 825.0 MHz
Duplex spacing 45 MHz
Frequency stability ±0.1 ppm
Antenna output
power 6 W Duplex filter
6 W TxBP filter
Antenna impedance 50 ohms
Frequency range Tx: 935.0125 - 940.9875 MHz
Rx: 896.0125 - 901.9875 MHz
Duplex spacing 39 MHz
Frequency stability ±0.1 ppm
Antenna output
power 3 W Duplex filter
3WTxBPfilter
Antenna impedance 50 ohms

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6.1.4 Frequency Band 900 MHz (HRB 104 43/C7, C8)
For a list of all Product Numbers, please refer to the Introduction and Product
Specification section in the BRU3 - General module.
Frequency range Tx: 935.0125 - 940.9875 MHz
Rx: 896.0125 - 901.9875 MHz
Duplex spacing 39 MHz
Frequency stability ±0.1 ppm
Antenna output
power 6 W Duplex filter
6WTxBPfilter
Antenna impedance 50 ohms