1

Motorola BTS

Objective

To be able to understand the functional areas of Motorola Horizon I&II macro cabinet, description of their digital modules and cabinet RF components

Introduction & description of VSWR, RF feeder cables and antennas

To understand BTS Command Interface with Procom plusTX Calibration of single/double density DRIs

3

Table of Contents

• Introduction to BSS

• BTS Basics

• HMAC II & I features

• VSWR, Antenna Tilting

• DRIs TX/RX Calibration

• Command interface

• Tools Required

Introduction to BSS

ACEIR

BTS

OMC

MSC

VLR

HLR

BSC

BTS

BTS

BTS

BTS

BSC

BSS - Base StationSubsystem

NSS - Network Subsystem

NMS - Network Management SystemMS

AbisAir A

IWF

SC

PSPDN

PSTNISDN

Transcoder

GSM Architecture

Transcoder function

Although transcoder is considered to be a part of BSS, it is most often located closer to MSC. Basic function is to reduce the data rate of the signals from MSC

BTS Site

A base transceiver station (BTS) or cell site is a piece of equipment that facilitates wireless communication between user equipment (UE) and a network.

BTS Site Block Diagram

• Main Processor Alarms collection and management, transceivers management, software download, controlling expansions and interface panels

• Clock source unitDeliver a stable clocking source to all digital equipments

• Interface Panel Translate the source data (Abis) to BTS Format digital data

• Base Band Unitthe digital data is processed following the GSM standard, this unit creates a data which ready to be feed to RF Unit

• Power Supply Unitproduces a power for whole equipments in the BTS

• RF Unitconverts the digital signal to Radio Frequency Signal (air interface signal) following the GSM Standard. This signal type is still as an electrical signal.

• Antenna UnitAntenna as a traditional unit, have a function to convert electrical signal to electromagnetic signal.

Three Main Functional areas:

1. Digital Cards

2. Radios (CTU/CTU2)

3. RF equipment

RF interface to Antenna( Transmit - Combining and filtering)

(Receive – Amplification and filtering)

DRI DRI DRI DRI DRI DRI

E1 Link Digital Cage == Controls the cabinet Alarms Power Supplies

Antenna

Basic block diagram of cabinet

Site Controller (HIISC)

CTU2

Cooling Fans

Power Supply Units (PSU)

Circuit Breaker

Card (CBC)

Alarm Board

HMACII Front View

Site I/O Panel

Tx Blocks

Link Interface

Board

SURF2Power Supply

EAS Alarm, PIX 0 & 1

HMAC II Front view

Maximum 4x PSU per cabinet – One for RedundancyDepends on the number of Radios fitted.

The Cabinet can support the three types of power supply

• +27V (negative earth)• -48V (positive earth)• Nominal 120/240V AC

Power Supply Unit

Nominal Voltage

Voltage supply range

Current supply maximum

+27 V dc (negative earth)

+19.5 to +30 V dc

204A (at nominal voltage)

-48 v dc

(Positive earth)

-39 to –72 V dc 99A (at nominal voltage)

120/240 V ac

(50 to 60 Hz)

88 to 270 V 45A (at nominal voltage)

Power Supply Unit

Air Vent

Alarm LED

Output Disable switch

Active LED

Attachment

screw

Handle

-48 VDC Power Supply Unit

All three unit types support the same PSU Alarms:

• O/P over/under voltage.• I/P under voltage.• Over temperature.• Internal Fan failure.

PSU Alarms

6x CCB for CTU2

2x Push Button HIISC

2x Push Button SURF2

1x Tx RF Blocks

1x FAN trays

Circuit Breaker Card (CBC)

Status LEDs

Compact Flash Slot

TTY MMI

Reset Buttons

HIISC Controller

HIISC controller acts as a main processor for horizon macro II cabinet. Its main features include

•Backward compatible with MCUF

•Integrated NIU

•Integrated FMUX

•E1 Support

•Enhanced E1 redundancy

•Removable flash media capacity

XMUX in slot 0

Expanding a BTS

Fibre connections

IN/OUT

XMUX Location

Horizon IICabinet

H-II Radio

NBSCHIISC

Alarm

CTUII radio(s)

TDM

Site IO

H-II ExpansionCabinet

Site IO

XMUX

XMUX

HorizonmacroCabinet

FMUX

FMUX

Alarm

Components interconnections

Site Expansion Board

Connects up to 3x extra cabinets

Fibre optic connections

GPS connector (not supported)

Input/Output I/O Card

Horizon IImacro (6xCTU2)

XMUX

Horizon IImacro (6xCTU2)

E1

Two Horizon II macro’s expanded.

Horizon IImacro (6xCTU2)

XMUX

Horizon IImacro (6xCTU2)

Horizonmacro (6 x CTU)

FMUX

E1

Horizon II macro, expanded to a Horizon II macro and a Horizonmacro.

Horizonmacro controlling a Horizon II macro and another Horizonmacro.

Expansion configurations

• Operating range -5 C to +45 C

• Three Internal FAN units – speed controlled

• 3x Cabinet Temperature Sensors – » 1x (70 C) for cabinet alarm» 2x (85 C) to shutdown the cabinet, reset at 55 C.

Cabinet Temperature Control

Mains

Door 1

LVD

Fan 0

Fan 1 & 2

ALL LEDs are GREEN when the equipment is OKRED when equipment is faulty

Alarm Board

Provides External alarm monitoring from the cabinet via the backplane

• Cabinet Power Supply Units

• Environmental controlled devices(over temperature

• Customer defined alarms(EAS)

• Antenna VSWR monitoring(via TX blocks)

Compact Transceiver Unit ( CTU2)

Single Density Mode – High Power 63W (48dbm) 900MHz

50W (47dbm) 1800MHz

Normal Power 20W (43dbm) 900MHz

16W (42dbm) 1800MHz

Double Density Mode –Normal Power 20W (43dbm) 900MHz

16W (42dbm) 1800MHZ

TRANSMIT RF OUT

TTY INTERFACE

Radio Status LED

Tx Status B LED

Tx Status A LED

The CTU2 transceiver has the ability to support two logical carriers within a single transceiver unit. A CTU2 is backward compatible with HMAC I through software control.

Compact Transceiver Unit 2 (CTU2)

RF Equipment

RF Equipment

Sectorized Universal Receiver Frontend

Diversity Antenna

Transmitter RF BlocksNew RF Blocks:• DUP - Duplexer• HCU - Hybrid Combiner Unit• DHU - Dual Hybrid Combiner Unit

Connecting Panels• Blanking Plate• Feedthrough plate

Cabinet TX Blocks

Feedthrough and Connecting

Plates

Duplexer

RX Connector

SURF

Duplexer Feedthrough Plate

Blanking Plate

DUP Block Diagrams

DHU & HCU Block Diagrams

CTU2

Signal

Tx Block

Rx Filter

Tx Filter

VSWRMonitor

AlarmBoard

AntennaTo SURF

Tx

• The Antenna VSWR monitoring function is used to detect faults in antennas or antenna path connections.

VSWR Monitoring

HMAC I

HMAC I cabinet comprises of three main parts

•Power Supply Module•Circuit Breaker Module•Binary PSM

Main features of MCUF Include

• Maintenance and operational/control processing• Switching of traffic and control information• The functionality of two FMUX• Support up to six transceivers via backplane in first cabinet and up to an additional 18 transceivers via FMUX connections to other cabinets• Support of up to six E1 circuits, via NIU modules

MCUF Controller Card

Compact Transceiver Unit 1 (CTU)

It contains Digital Circuits which provide the following capabilities:

• Handling the process of Encoding, Decoding.• Handling of 8 time slot (1 carrier signal).• Transmit power control. • Handling the diversity process which will improve the reception process

Power Supply Module

BPSM Card

Circuit Breaker Module

Function Horizon II macro component Horizonmacro I equivalent

Input power conversion units (max fitted) PSU

(4)

PSM

(3)

Power to transceivers and signal routeing Backplane BPSM and backplane

Transceivers

(max fitted)

CTU2

(6)

CTU

(6)

Main processor module

(Max fitted)

HIISC

(2)

MCUF

(2)

Processor module connection to transceivers

in another cabinet

Internal XMUX in HIISC (1) and

separate site expansion boards

(1 or 2)

Internal FMUX in

MCUF (2) or

external FMUX (2)

Slave cabinet multiplexer XMUX FMUX

Rx components

(Max fitted)

SURF2

(2)

SURF

(1)

Transceiver to Rx components SURF2 harness SURF harness

TX blocks

(Max fitted internally)

DUP, HCU and DHU

(6)

DCF, TDF, DDF and HCU

(3)

DC power supply for digital modules

(Max fitted)

Integrated in HIISC supplied via

backplane

BPSM

(2)

Equipment protection/isolation CBC CBM

Links to terrestrial network

(Max fitted)

Internal NIU in HIISC NIU

(4)

Alarm Handling Alarm Module *** Alarm Module

E1/T1 links CIM/T43 or BIM/BIB CIM/T43 or BIM/BIB

HMAC II vs HMAC I

Voltage standing wave ratio (VSWR) is the ratio of the maximum voltage amplitude of a reflected wave ( ) to the minimum voltage amplitude ( ), in an electrical transmission line.Reflections occur as a result of discontinuities, such as an imperfection in an otherwise uniform transmission line, or when a transmission line is terminated with other than its characteristic impedance.

ρ = | | (Reflection Coefficient)

Voltage Standing Wave Ratio (VSWR)

DBC(DUAL BAND CMBINERS) ( MAX 1.09)

VSWR Standards

BTSBTS

DBCDBCArrestorsArrestors

Antenna Jumper

Antenna1.04

1.091.06

1.08

1.16

GSM Measure Match = 1.35DCS Measure Match = 1.45

1

1.0

1.1

1.2

1.3

1.4

0 5 10 15 20 25 30 35 40 45 50

Limit: 1.400

Distance To FaultDistance: 0 meters - 50 meters (Full Cal)

PSH.0014.RMC.DCS.SEC.B1 9/11/2008 5:11:00 PM

M1:( 32.81, 1.18)

VS

WR

Distance (meters)

1

1.0

1.1

1.2

1.3

1725 1750 1775 1800 1825 1850 1875

VSWRFrequency: 1710 MHz - 1880 MHz (Full Cal)

PSH.0014.RMC.DCS.SEC.A 9/11/2008 5:23:00 PM

M1:(1879.28, 1.35)

VS

WR

Frequency (MHz)

Fault Location

Measure Match

50 ohm RF Communication feeder cable Advantages:

1. Excellent Electrical performances: 80% super-high degree foaming polyethylene insulation of features with low attenuation and stability in case of temperature variation. The extra-precisely corrugated copper tube outer conductor, characteristic of low VSWR makes the cable a choice even in high-frequency applications.

2. Simple use and complete range: The light, flexible and easily-bending thin-wall corrugated copper conductor offers convenience for terminal work.

3. Ease of maintenance: The special structure presents premises for effective moisture-proofing, thus assuring performances stability in terms of long period.

RF cable Advantages

All outdoor antenna feeder runs should be grounded at theirlowest point just prior to entering the base station or radioenclosure. Depending on the height of the tower run, additionalground points may be required (see table below).

RF Cable Grounding Locations

Grounding Kit

Grounding Kit

Bundled grounding

Individual grounding

Site Master

Insulation cutter

Warding FilesKnife

Open End Spanners Closed End Spanners

Adjustable SpannersCable Cutter

Tools Required (VSWR)

EMR

Antennas

Antenna

A dipole antenna is an antenna that can be made by a simple wire, with a center-fed driven element for transmitting or receiving radio frequency energy.

An antenna (or aerial) is a transducer that transmits or receives electromagnetic waves. In other words, antennas convert electromagnetic radiation into electrical current, or vice versa. Physically, an antenna is an arrangement of one or more conductors, usually called elements

Emission (Radiation) Pattern

Emission of a dipole is maximal in the plane perpendicular to the dipole and zero in the direction of wires, that is, the current direction.

Electromagnetic Radiation (EMR)

EMR comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation.

The polarization of anelectromagnetic wave is defined as theorientation of the electric field vector

Beam Tilting

Beam tilt is used in radio to aim the main lobe of the vertical plane radiation pattern of an antenna below (or above) the horizontal plane.

Simplest way is mechanical tilting, but it creates a back lobe

More common is the electrical tilting, where the phasing between antenna elements is tweaked to make the signal go down (usually) in all directions

Tilt Vs Gain

BTS Command Interface

Procom Plus

Display Alarms (EAS/IAS)

DRI Status

Radios Classification/Configuration

SECTOR A GSM 900

DRI 0 0 0DRI 0 1 0DRI 0 2 0DRI 0 3 0

SECTOR B GSM 900 DRI 1 0 0DRI 1 1 0DRI 1 2 0DRI 1 3 0

SECTOR C GSM 900 DRI 2 0 0DRI 2 1 0DRI 2 2 0DRI 2 3 0

SECTOR A DCS 1800

DRI 3 0 0DRI 3 1 0DRI 3 2 0DRI 3 3 0

SECTOR B DCS 1800 DRI 4 0 0DRI 4 1 0DRI 4 2 0DRI 4 3 0

SECTOR C DCS 1800 DRI 5 0 0DRI 5 1 0DRI 5 2 0DRI 5 3 0

Common configuration with 3 DCS 1800 DRIs (one in each Sector) and 3 GSM 900 DRIs (one in each sector)

GSM 2/2/2 DCS 2/2/2

Alarms Equipage

BSC MMS Identifiers

Site IDs/Status

Site RSL Status

BSC RSLs Status

All Sites Status with codes

All Sites Status with codes

MMS Status

BSC OML Status

Path Balance

Path balance = (UL losses - dl losses) + 105

where 105 is the optimum value for the path balance

In case of -ve path balance, the DL losses are greater which means a TX calibration for the BTS is needed (adjust TX power)

In case of +ve path balance this, the UL losses are greater which means RX calibration is needed to adjust the sensitivity of the RX of the BTS

GSM Cell Data

Display Intervals

DRI Equipage

Level 2 / Level 3 access

DRI Calibration Data

BSC MTLs Status

BSC XBLs Status

BSS Test Equipments

Thanks