explain m04 - 1 configuration planning

1 © NOKIA 6-90198/ CONFIGURATION PLANNING/ v 1.0

ConfigurationConfigurationPlanningPlanning


Module objectives

LIST THE DIFFERENT ELEMENTS USED IN THE GSM NETWORK

CALCULATE THE POWER BUDGET

DESCRIBE HOW TO BALANCE UPLINK AND DOWNLINK DIRECTIONS IN THE POWER BUDGET

At the end of this module you will be able to …


Content of Configuration Planning

NETWORK ELEMENTS

POWER BUDGET


Configuration Planning

NETWORK ELEMENTS

POWER BUDGET


GSM Architecture & Interfaces

BSC

HLR/AC/EIRTCSM

MSC/VLR

BTS

AbisInterface

AterInterface

AInterface

AirInterface

TC

Ater’Interface

Air interface OPEN• 13 kb/s traffic channels• 8 channels / TRX• some channels reserved for signalling• blocking

Ater interface PROPRIETARY• 16 kb/s traffic channels• up to 120 traffic channels / 2M frame• 64 kb/s CCS#7 signalling• 64 kb/s channels for X.25 NMS connection• blocking

Abis interface PROPRIETARY• 13 kb/s traffic channels• up to 96 traffic channels / 2M frame• one TRXSIG signalling channel / TRX• one BCFSIG signalling channel / BTS• 16, 32 or 64 kb/s signalling rates

A interface OPEN• 64 kb/s traffic channels• 30 traffic channels / 2M frame• 64 kb/s CCS#7 signalling• 64 kb/s channels for X.25 NMS connection


Network Elements Terminal


Network ElementsMobile Phone

Terminal• Voice and data transmission• Long battery life-time• Low weight, easy handling

SIM card• Personal identity number• Access permissions• Phone number memory• Security algorithms• PIN-codes


Network Elements Mobile Phone - Speech Processing Flow

Interleaving

Burst FormattingCipheringModulation

ChannelCoding

Digitising andSource CodingSpeech

RF Base Band


Network Elements BTS


Network ElementsTasks of BTS

Base Transceiver Station• Maintain synchronisation to MS• RF signal processing (combining, filtering, coupling...)• Diversity reception• Radio interface timing• Detect access attempts of mobiles• De-/ encryption on radio path• Channel de-/ coding & interleaving• Perform frequency hopping• Forward measurement data to BSC

typically 1 - 4 TRX / sectortypically 1 - 3 sectorsavg. 7,5 traffic channels per TRX


Network Elements UltraSite WCDMA

Key Functionality

Nokia UltraSite WCDMA BTS is a part of UltraSite Solution. For the initial launch of the WCDMA, all Nokia WCDMA BTSs will be optimised for fast and easy rollout allowing the WCDMA to be deployed rapidly over the initial service area. Good uplink performance and high capacity are essential for WCDMA networks and Nokia's features support these functions. Nokia UltraSite Base Station family products are available in both indoor and outdoor versions.Key Benefits

• High capacity multistandard BTS family • UltraSite cabinets can be installed side by side • Utilisation of existing equipments and GSM/WCDMA co-siting are supported • Mobile multimedia platform for high capacity voice and data services • Evolution path to All-IP technologies is secured


Network Elements UltraSite EDGE

Nokia UltraSite EDGE BTS Outdoor, Indoor, and Midi Indoor

Features and benefits

Nokia UltraSite EDGE BTS has many features and benefits, such as:

• Nokia UltraSite EDGE BTS is light weight and compact and, with its fullfrontal accessibility, can be installed just about anywhere.

• The modular design of Nokia UltraSite EDGE BTS guarantees smoothexpansion and upgrades of base station equipment with minimaldisturbance to network operation. In addition, the BTS supports hotinsertion of plug-in units, which means that most units can be replaced during operation without disrupting the BTS functions.

• Nokia UltraSite EDGE BTS cabinets can be installed side by side and in corners, which means less space is required.

• Nokia UltraSite EDGE BTS fits into the corresponding Nokia Talk-family BTS footprints. The operator does not need to alter any previous plans for expansion. In addition, the BTS can be co-sited with Nokia Talk-family as an upgrade cabinet.

Nokia UltraSite EDGE BTS is available in different cabinets for outdoor andindoor applications:

• Nokia UltraSite EDGE BTS Outdoor• Nokia UltraSite EDGE BTS Indoor• Nokia UltraSite EDGE BTS Midi Indoor (used when vertical space islimited)


Combiner by-pass

Network Elements UltraSite EDGE RF Performance in GSM 900

WBC 2:1WBC 4:1RTC

Output powerdBm W

Max # of TRXs / Frequencyantenna element hopping

42.0

44.541.037.5

15.8

28.212.65.6

1246

RF & BBRF & BBRF & BB

BB

BTS Output Power

Static, single branch

w/o MHA with MHA

Dynamic, single branch2-way diversity (all profiles)4-way diversity (all profiles)

-110.5 dBm -111.0 dBm-108.5 dBm -109.0 dBm-113.5 dBm -114.0 dBm-116.5 dBm -117.0 dBm

BTS Receiver Sensitivity

MHA figure includes the cable losses



WBC 2:1WBC 4:1RTC

Combiner by-pass

Output powerdBm W

Max # of TRXs /antenna element

Frequencyhopping

42.0 / 41.3

44.5 / 44.041.0 / 40.337.5 / 36.6

15.8 / 13.5

28.2 / 25.1 12.6 / 10.75.6 / 4.6

1246


BB

BTS Output Power

SB / FB


w/o MHA with MHA


-112.0 /-111.5 dBm -112.5 dBm-110.0 /-109.5 dBm -110.5 dBm-115.0 /-114.5 dBm -115.5 dBm-118.0 /-117.5 dBm -118.5 dBm


SB / FB SB




WBC 2:1WBC 4:1RTC

Combiner by-pass

Output powerdBm W

Max # of TRXs / Frequencyantenna element hopping

42.0

44.541.037.5

15.8

28.212.65.6

1246


BB

BTS Output Power


w/o MHA with MHA


-111.0 dBm -112.0 dBm-109.0 dBm -110.0 dBm-114.0 dBm -115.0 dBm-117.0 dBm -118.0 dBm




Network Elements Talk-family Base Station

Key Functionality

Nokia Intratalk (indoors) and Citytalk (outdoors) are base stations that can accommodate up to 12 TRX in omni or sectored configurations in two cabinets. Nokia Flexitalk Base Station is a compact Base Station with flexible configuration from 1 boosted TRX to 2 TRX omni configuration. The modular architecture and various antenna combinations help to achieve the best coverage and capacity solution. Nokia Talk-family base stations support GSM data evolution with the capabilty to support high speed circuit switched data (HSCSD) and GPRS.

Key Benefits

• Flexible configurations and solutions from initial coverage building to large capacity sites • Smooth evolution path to 3G services with co-siting solutions • Protected investment through future-proofed expandability • Field-proven technology with high reliability


Network Elements MetroSite

• The Nokia MetroSite GSM BTS is a complete, all-climate microcellular base transceiver station.

• It can be used in GSM 900, GSM 1800, GSM 1900 systems, or as a GSM 900/GSM 1800 dual band BTS.

• Both omni and sectored configurations are supported.

• The small-sized Nokia MetroSite GSM BTScabinet accommodates up to four transceiver units (TRXs).

• In order to ensure high quality of calls, the Nokia MetroSite GSM BTS supports versatile features, such as frequency hopping.


MetroSite ConceptNokia MetroSite

Base Station

Connected to FXC RRI orFC RRI indoor unit.

Connected to FXC RRI orFC RRI indoor unit.

Nokia MetroHopper Radio

Nokia MetroHubTransmission Node

Nokia FlexiHopperMicrowave Radio

Nokia MetroSiteBattery Backup

Nokia MetroSiteAntennas


New MetroSite Family Members

Nokia MetroSite WCDMA Base Station

Nokia FlexiHopperMicrowave Radio (PDH)

Nokia MetroHopperRadio

Nokia UltraHopperMicrowave Radio (SDH)

High-power Nokia MetroSite GSM Base Station

Nokia MetroSite GSM Base Station

Nokia MetroHub Transmission

NodeNokia MetroSiteBattery Backup Unit


Nokia MetroSite Base Station Antennas

Directional 130 degrees: 6 dBi Omnidirectional: 2 dBi

• Dual band 2 port antennas• GSM 900 / GSM 900• GSM 900 / GSM 1800• GSM 1800 / GSM 1800

• 1 feeder per TRX

• No internal combiners needed

• RX diversity

• External 2 to 1 combiner available for special cases


Network Elements PrimeSite

• Nokia PrimeSite is a complete 1 TRX Base Transceiver Station for both indoor and outdoor use in 900 MHz (GSM 900), 1.8 GHz (GSM 1800), and 1.9 GHz(GSM 1900) systems.

• The product has been optimized for one carrier.

• The number of TRXs can be increased by chaining several Nokia PrimeSites with a single clock synchronization cable between each unit.

• Nokia PrimeSite conforms to both GSM Phase I and Phase II requirements.

• The product is in link balance with 2WMS for GSM 900, and 1WMS for GSM 1800 and GSM 1900.


Network Elements InSite

Key Functionality

Nokia InSite Base Station is a compact, one-transceiver picocellular base station (BTS) for a variety of indoor coverage and capacity solutions. This tiny GSM/GPRS BTS is available in 900 and 1800 and 1900 MHz. Weighing just 2.4 kg and no bigger in area than a sheet of A4 paper, it can be installed virtually anywhere. Compact and integrated system elements, highly automated configuration and flexible transmission, means this base station can be installed in about one-tenth the time of other base stations giving fast return on investment. Rollout can cost a fraction of that of conventional indoor networks.Key Benefits

• Dedicated indoor solution at a fraction of the conventional cost, means less capital expenditure • Single TRX picocellular base station for smooth growth of your indoor network • Highly automated and integrated system speeds up implementation and enables faster return on investment • Compatibility with future technology developments helps ensure cost-effective network upgrades • Network integration typically achieved during one site visit by one person


Nokia FlexiTalk1 - 2 TRX

Nokia MetroSite 1 - 4 TRX

Nokia CityTalkNokia IntraTalk

1 - 6 TRX

Coverage

Capacity

Nokia InSite1 TRX

Network Elements Nokia BTS's

Nokia UltraSite1 - 108 TRX


RF Characteristics Metrosite PrimeSite InSite Flexitalk Intratalk Citytalk Ultrasite EDGE

Max. TRXs 4 1 1 2 6 6 6

Max. TRXs Special Cabinet

12 12 108

Max. Sectors 4 1 1 1 4+4+4 4+4+4 36+36+36

Max TX Power (dBm)

30 38 22 42 42 42 42

Dynamic sensitivity (dBm) single branch, RBER2<2%

-106.0 -106.0 -100 -102/-108 -102/-108

-102/ -108

-108.5/ -109

Network Elements Nokia BTS's - Summary


Network Elements Antennas


Antennas Categories

Omnidirectional antennas• Radiation patterns is constant in the horizontal plain• Useful in flat rural areas

Directional antennas• Concentrate main energy into certain direction• Larger communication range• Useful in cities, urban areas, sectorised sites


AntennasAntenna Gain

• Measures the antenna´s capability to transmit/extract energy to/from the propagation medium (air)

• dB over isotropic antenna (dBi)• dB over Hertz dipole (dBd)

• Antenna gain depends on• Mechanical size: A• Effective antenna aperture area: w• Frequency band

• Antenna Gain: G A w=4

2π

λ

Pt

Gain (Dbi)

Isotropic radiated Power

Equivalent isotropicradiated power:EIRP = Pt+Gain(Dbi)

radiatedpower


AntennasCharacteristics

• Lobes• Main lobes• Side / back lobes• Front-to-back ratio

• Halfpower beam-width (3 dB- beam width)

• Antenna downtilting

• Polarisation

• Antenna bandwidth

• Antenna impedance

• Mechanical size• Windload

InputConnector positionFrequency rangeVSWRGainImpedancePolarisationFront-to-back-ratioHalf-power beam width

Max. powerWeightWind load

Max. wind velocityPacking sizeHeight / width / depth

7 /16” femalebottom870 - 960 MHz< 1,315,5 dBi50 Ohmvertical> 25 dBH-plane: 65° / E-plane: 13°

500 Watt (50 °C ambient temp.)6 kgfrontal : 220 N (at 150 km/h)lateral: 140 N (at 150 km/h)rear : 490 N (at 150 km/h)1410 x 270 x 140 mm1290 / 255 / 105 mm


0 dB

-3 dB

-10 dB

0 dB

-3 dB

-10 dB

Vertical BeamHorizontal beam

side lobe

null direction

main beam

HPB

W

AntennasRadiation Pattern


Mechanical• Later adjustment of vertical tilt possible and fast• Antenna diagram doesn’t change• Cost effective (single antenna type may be used)

Electrical• Same tilt for both main and side lobes

⇒ better for interference• Antenna mounting is more simple

⇒ no adjustment errors• Several types of antennas

τ = 0

τ = t

τ = 2 t

τ = 3 tτ = delay time

downtilt angle

AntennasDowntilt


• def = Attenuation between TX & RX antenna connectors

• Horizontal separation• needs approx. 5λ distance for sufficient decoupling• antenna patterns superimposed if distance too close

• Vertical separation• distance of 1 λ provides good decoupling values• good for RX /TX decoupling

• Minimum coupling loss

main lobe

5 .. 10 λ

1λ

AntennasDecoupling


Antennas

> X-pol panel antenna 1800MHz 2x18dBi 65deg

ELECTRICAL SPECIFICATIONS• Intermodulation IM3 (2 x 43 dBm carrier)< -150 dBc• Frequency range1710 - 1880 MHzVSWR< 1.5• Gain2 x 18 dBi• Impedance50 ohm• Polarization+45°, -45°• Front-to-back-ratio, co-polar> 30 dB• Half-power beam width+45° • polarization: horizontal 65°, vertical 6.5°-45° polarization:

horizontal 65°, vertical 6.5°• Maximum power per input200 Watt (at 50°C ambient

temperature)• Grounding The metal parts of the antenna including the mounting

kit and the inner conductors are DC grounded.• Isolation, between ports> 30 dB

ENVIRONMENTAL SPECIFICATIONS• Ice protection

•Due to the very sturdy antenna construction and the protection of the radiating system by the radome, the antenna remains operational even under icy conditions.

GENERAL• Short sales item description X-pol panel 1800MHz 2*18dBi 65deg

MECHANICAL SPECIFICATIONS• RF connector type2 x 7-16 female RF connector position Bottom

or topWeight6 kg Wind load Frontal: 310 N (at 150 km/h) Lateral:110 N (at 150 km/h) Rearside: 250 N (at 150 km/h) Maximum wind velocity200;


Installation Examples

• Recommended decoupling• TX - TX: ~20dB• TX - RX: ~40dB

• Horizontal decoupling distance depends on• Antenna gain• Horizontal rad. pattern

• Omni directional antennas• RX + TX with vertical separation (“Bajonett”)• RX, RX div. , TX with vertical separation (“fork”)

Vertical decoupling is much more effective

0,2m



Pole mounting for roof-top mounting

Tower mounting for directional antennas



Both the area near and far away from BTS receive a strong signal

Main Lobe

No shadow of radio signal

Main Lobe

Shadow of radio signal

The strongest signal is far away from Base Station


Nearby Obstacles Requirement(1/3)


Height Clearance vs Antenna Tilt

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

5 10 15 20 25 30 35 40 45 50

Roof Edge d (m)

h (m)

From 0deg. up to 6deg. down tilt∆h

h



• Time diversity

• Frequency diversity

• Space diversity

• Polarisation diversity

• Multipath diversity

• Interleaving

• Frequency hopping

• Multiple antennas

• Crosspolar antennas

• Equaliser• Rake receiver

t

f

DiversityDiversity Technics


• Selection diversity

• Maximum ratio combining

• pre-detector combining:

• ⇒ add signals in correct phasing

• C/I improvementC/N measuring

Phase measuring

Φ2

Φ1

G3

G2

G1

+

Φ3

DiversityDiversity Receptions


• Diversity gain depends on environment

• Is there coverage improvement by diversity ?• Antenna diversity

• equivalent to 5dB more signal strength• more path loss acceptable in link budget• higher coverage range

R

R(div) ~ 1,3 R

A 1,7 A ??70% more coverage per cell ??needs less cells in total ??

True only (in theory) if the environment is infinitely large and flat

DiversityCoverage Improvement?


Space diversity

• 4-5 dB gain in different environments if antenna separation is sufficient!

• Signal levels at an equal level!

• Antenna separation 1-20 λ depending on the environment!

• 1-2 λ for microcellular

• 10-15 λ for urban/suburban

• 15-25 λ for rural

Performance of Diversity Technologies


Polarization diversity

• Indoor 6 dB

• Urban 6 dB

• Semi-urban / microcellular 4-5 dB

• Light suburban 3 dB



Example of recommendations

Urban/Suburban/Microcellular/Indoor environments

• Use polarization diversity reception

• Use ± 45° slanted polarizations

• Gain = 4-5 dB @ 900 MHz and 5-6 dB @ 1800 MHz

Rural environments

• Use space diversity, implement in vertical direction close to each other

• Gain app. 3 dB (”combining gain”)

• Or use polarization diversity for special configurations

• Use LNAs for both diversity branches



Space diversity• TX-TX isolation > 20 dB

• TX-RX isolation > 40 dB

=> separation of TX/RX and RXd antennas app. 0.5-2.0 m depending on element types!

=> vertical separation typically less than horizontal!

Polarization diversity• TX-TX isolation > 20 dB

• TX-RX isolation > 30 dB

=> separation of TX/RX and RXd branches not needed!

POLARIZATION DIVERSITYANTENNAS CAN BE USED IN DIFFERENT SPECIAL CONFIGURATIONS AS IN

• 2 TRX rural base stations where coverage has to be maximised!

• In booster/PA configurations!

Antenna Configuration Conclusions


Network Elements Cables


• Cable types• Coaxial cables: 1/2”, 7/8”, 1 5/8”• Losses approx. 10 … 4 dB/100m

⇒ power dissipation is exponential with cable length!

• Connector losses approx. 1 dB per connection (jumper cables, etc…)

• Thick antenna cables• Lower losses per length• Large bending radii• Much more expensive

jumper(2 m)

40 ..

70m

jumper(2 m)

Keep antenna cables short

Cables


Network Elements Cables


Network Elements Filters and Combiners


Network Elements Filters and Combiners, AFE

Antenna Filter Extension (AFE)• Wide band combiner/receiver unit• Allows 2 TRX’s to be attached to a single antenna• TX combining is performed by a built-in 3 dB hybrid combiner• 1 TRX/sector: combiner bypassed

Dual Duplexed AFE• 4 TRX sectors can be built by cabling two AFE’s and 4 TRX’s together• 4 RX outputs for the main branch• Can be used with Intratalk and Citytalk BTSs


-3 dB loss

Configurations AFE with X-pol div 2+2+2

TX1, TX2, RX1, RX2

RXdiv1, RXdiv2

CABINET

TRX1TX1RX1RXdiv1

TRX2

TX1TX2RX1RX2RXdiv1RXdiv2

AFETX2

RX2RXdiv2


-3 dB loss

CABINET 1

TRX1TX1RX1RXdiv1

TRX2

TX1TX2RX1RX2RX3RX4

AFETX2

RX2RXdiv2

CABINET 2

TRX3TX3RX3RXdiv3

TRX4

TX3TX4RXdiv1RXdiv2RXdiv3RXdiv4

AFETX4

RX4RXdiv4

TX1, TX2, RX1, RX2, RX3, RX4

TX3, TX4, RXdiv1, RXdiv2, RXdiv3, RXdiv4

Configurations AFE with X-pol div 4+4+4


Network Elements Filters and Combiners, AFT

Antenna Filter Twin (AFT)• Supports dual duplex of RX and TX into common antennas • It doesn’t combine, just route the TX to its own antenna output • No 3 dB hybrid coupler • Should be used with masthead LNAs • Up to 2+2+2 configuration


no loss

Configurations AFT with Space div 2+2+2

TX1, RX1, RX2

TX2, RXdiv1, RXdiv2

CABINET

TRX1TX1RX1RXdiv1

TRX2

TX1TX2RX1RX2RXdiv1RXdiv2

AFTTX2

RX2RXdiv2


no loss

CABINET 1

TRX1TX1RX1RXdiv1

TRX2

TX1TX2RX1RX2RX3RX4

AFTTX2

RX2RXdiv2

CABINET 2

TRX3TX3RX3RXdiv3

TRX4

TX3TX4RXdiv1RXdiv2RXdiv3RXdiv4

AFTTX4

RX4RXdiv4

TX1, RX1, RX2, RX3, RX4

TX4, RXdiv1, RXdiv2, RXdiv3, RXdiv4

Configurations AFT with X-pol div 4+4+4

TX2

TX3


Network Elements Filters and Combiners, RTC

Remote Tuned Combiner (RTC)

• Narrow-band cavity combiners tuned remotely to the TRX frequency• Separate Receiver Multicoupler Unit (RMU) is always needed• RTC/RMU combination supports up to 6 TRX/sector• Combining loss with RTC is lower than with AFE• Synthesized frequency hopping is not supported


CABINET 1

TRX1TX1RX1RXdiv1

TX1TX2TX3TX4TX5TX6

RTCTRX2

TX2RX2RXdiv2

TRX3TX3RX3RXdiv3

TRX4TX4RX4RXdiv4

TRX3TX3RX3RXdiv3

RX1...RX6RXdiv1...RXdiv6

RTC

TRX4TX4RX4RXdiv4

ConfigurationsRTC with X-pol div 6+6+6

TX1, ..., TX6, RX1, ..., RX6

RXdiv1, ..., RXdiv6


Network Elements TRX


Network ElementsTRX

Interface• The Interface converts the baseband (BB)

data stream to GMSK modulation for the TX. It also converts the analogue RX frequency signal from the main and diversity branches to the data stream. The Interface controls all synthesisers and the TRX loop. It also handles clock distribution from the BB2x unit and alarm


Network ElementsTRX

Transmitter (TX)• The intermediate frequency (IF) sections in the TX raise

the signal to the carrier frequency. Thereafter, the RF section amplifies the signal to the desired output signal amplitude. The RF section also handles the signal power control.

• The TSxx unit supports 16 power levels with 2 dB steps, with a maximum range of 30 dB. Power levels from 0 to 6 are static; power levels from 7 to 15 are dynamic.

Receiver (RX)• The RF section of the RX converts the carrier frequency

signal to the IF frequency.• The IF sections of the RX perform channel filtering and

prevent interfering frequencies from distorting the signal. The IF sections also provide automatic gain control.

TRX loop• The TRX loop supports the self-testing of the TSxx unit.

The tests are carried out by converting the frequency of the TX signal to the RX band. The signal is coupled from the TX output, and the resulting low-level signal is routed back through the RX path. The signal can be routed to the main branch or to the diversity branch.


Network Elements MHA & Booster


Network ElementsMHA

Mast Head Amplifier (Low Noise Amplifier)

• RX signal amplified near the antenna in the top of the mast• Offers better coverage • Eliminates the antenna cable loss • Increased receiver sensitivity of the BTS and cell size• Increased network quality

Noise Figure £ 2.0 dB (typical)RX Gain: Up to 12 dBDimensions : 266 x 130 x 123 mmWeight : 5.6 kg (duplexed)Volume : 4.2 lIP 65 Enclosure ProtectionPower Feeding Through Antenna CoaxAlarms handled in BTS


Booster

• TX signal amplified

• Nokia Booster Configuration• Booster (PA) Unit (TBU)• Booster Filtering Unit (AFH)• Masthead Preamplifier equipment (MHA)

• Output power before combining can be up to 49 dBm

• Isolator + combiner + filter (AFH) give roughly 2.5 dB losses

• Booster BTS is suitable for all the environments where enhanced coverage or high output power is needed

• Theoretically, cell radius is enhanced up to 60% and the coverage area is roughly the triple

Network Elements Booster

TRXTBUAFH


Network Elements Power Splitter


Network ElementsPower Splitter

Key Functionality

Low-loss power splitters and tappers are used for combining antennas to obtain particular radiation patterns or to set up indoor distribution networks.

Key Benefits• Low-loss coaxial-line transformation. • High power rating. • Equal (splitters) or unequal (tappers) power rating. • Suitability for indoor and outdoor use. • Extremely small dimensions and multi-band versions for 800 - 2200 MHz.


Network Elements Coupler


Network ElementsCoupler

Features• Wideband microstrip coupler with

internal termination resistors for power division to Indoor antennas.

• Frequency range suitable for GSM900, GSM1800, GSM1900 and 3G bands.

• Small size. Low insertion loss. N-female connectors used. No termination load needed. Fully sealed.


Network Elements Duplex Filter


Network ElementsDuplex Filter

The DVxx performs the following primary functions:

• Combines transmitted and received signals into one antenna

• Amplifies received signals with a variable-gain Low Noise Amplifier (LNA)


Network Elements Diplex Filter


Network ElementsDiplex Filter

The DU2A unit is a passive unit that serves the following purposes:

• Combines GSM 850/900 and GSM 1800/1900 TX signals into one antenna

• Receives GSM 850/900 and GSM 1800/1900 RX signals through one antenna


Network Elements BSC


Base Station Controller• Measurement + observation handling

• basic for most of the other functions

• Handover control• Power control• Frequency hopping management• Signalling management• Radio resource management• Maximum Capacity:

• BSSS7 Software Release• Basic + Extension Rack• UP TO 256 TRXs, 128 cells• BSSS8 Software Release• Basic + Extension Rack• UP TO 512 TRXs, 248 cells• BSSS9 GPRS• BSSS10.5 new features

Network Elements BSC Functions

typ. 80..512 TRXtyp. 50..80 base stationstyp. 3..5 PCM links to MSCsupports typ. 10,000 users


Network Elements Transcoder


Network ElementsTCSM

Transcoder Submultiplexer• Transcoding

• Performs speech coding • Bit rate changes from 64 kbps to 16 kbps

• TRAU Frame formatting • Speech bit rate after speech coding is 13 kbit/s, 3 kbit/s is used for inband signalling

• Submultiplexing• Combines traffic and signalling from 3 PCMs into 1 PCM

• Discontinuous Transmission• Voice Activity Detector & Comfort Noise Generator


Network Elements MSC


Network ElementsMSC

Mobile Switching Center• Typically for 150,000 subs

• At least one gateway to other networks

• Performs all routing, call control functions ...

MSC


Network Elements NMS


Network ElementsOMC (NMS)

Operation and Maintenance Center

(Network Management System)• Fault monitoring• Alarm handling• Performance measurements• OMC is connected to GSM network e.g. via X.25 link• Supervises all network elements• Collects measurement data• Remote handling of network elements

necessary tool for network optimisation


Configuration Planning

NETWORK ELEMENTS

POWER BUDGET


Power BudgetBasics

• Power budget is used to calculate the maximum allowed path loss

• Main factors depend on equipment characteristics • BTS & MS TX power• BTS & MS RX sensitivity

• Other factors can be classified into 3 categories and have to beestimated

• Loss factors• Gain factors• Margins (chapter 5)


~ 3 … 5 dB losses⇒ 50 … 70% of signal

power is lost before even reaching the TX antenna

Power BudgetLoss Factors

• At BS side• Connectors (UL/DL)• Cables (UL/DL)• Isolator (DL)• Combiner (DL)• Filter (UL/DL)

• At MS side• MS Antenna

• Polarization (UL/DL)• Connection (UL/DL)

• External cable

man

y m

eter

s

cables &connectors

filter

combiner

BS output


Power BudgetGain Factors

• At BS side• Antenna gain (UL/DL)

• Main antenna parameter• Slight difference between DL and UL• The antenna models in use should be defined at the very beginning of the project

• Diversity gain (UL)• Diversity can be implemented in many ways, with different gains

• LNA gain (UL) • Booster or power amplifier gain (DL)• Frequency hopping gain (UL/DL)

• FH improves average link quality, but it isn’t taken into account in power budget calculations

• At MS side• External antenna


path loss = 154 dB

combiner loss = 5 dB

Feeder Loss = 4 dB

Rx Sensitivity- 102 dBm

Tx Power45 dBm (30W)

AntennaGain = 16dBi

- 102 dBm

52 dBm

36 dBm

40 dBm

Power BudgetDownlink


path loss = 154 dBFeeder Loss = 4 dB

Tx Power33 dBm (2W)

AntennaGain = 16 dBi

DiversityGain = 4 dB

33 dBm

- 121 dBm

- 101 dBm

- 105 dBm

Rx Sensitivity-105 dB

Power BudgetUplink


Power BudgetExample

Power budget

GENERAL INFORMATIONFrequency ( 1800 System: DCS1800Case descrip MS Class: 1 RECEIVING END: BS MSRX RF- Input Sensitivity dBm -108.00 -100.00 AInterference Degradation Margin dB 3.00 3.00 BBody Proximity Loss dB 0.00 2.00 CCable Loss + Connectors dB 3.00 0.00 DRx Antenna Gain dBi 18.00 0.00 EDiversity Gain dB 4.00 0.00 FIsotropic Power dBm -124.00 -95.00 G=A+B+C+D-E-FField Strength dBµV/m 18.31 47.31 H=G+Z*TRANSMITTING END: MS BSTX RF Output Peak Power W 1.00 29.50(mean power over RF cycle) dBm 30.00 44.70 KBody Proximity Loss dB 2.00 0.00 LIsolator + Combiner + Filter dB 0.00 2.20 MRF-Peak Power, Combiner Output dBm 28.00 42.50 N=K-L-MCable Loss + Connectors dB 0.00 3.00 OTX Antenna Gain dBi 0.00 18.00 PPeak EIRP W 0.63 562.11(EIRP = ERP + 2dB) dBm 28.00 57.50 Q=N-O+P

* Z = 77.2 + 20*log(freq[MHz])LINK-BALANCE EVALUATION UL DLTheoretic Isotropic Path Loss dB 152.00 152.50 R=Q-GIsotropic Path Loss to be considered dB 152.00 UL Limited Min (UL,DL)Path Loss unbalancement dB 0.50 Abs (UL-DL)TX RF Max Output Power to be used dBm 30.00 44.20

BT99 - AFE with combiner bypass (equiv. to

1 2

3 4


Power BudgetConclusions

•Power budget has to be balanced, even if the BTS has higher TX power than the MS

• Diversity gain is for UL only

• BTS RX sensitivity is better than for the MS

•The maximum allowed path loss is usually UL limited

•There are as many power budgets as different site configurations are defined, even into the same project

• The site configurations in use should be defined at the very beginning of the project


Exercises / Questions

Calculate the power difference of TXMS = 33 dBm and TXBTS= 8 W in dB units.

Calculate the power imbalance for the GSM1800 system when TXMS = 30 dBm, TXBTS = 43 dBm, SENSITIVITYMS = -100 dBm and SENSITIVITYBTS = -108 dBm. Combiner unit is not used.

What is the maximum path loss for a good connection in the previous exercise?

Calculate the required gain for the LNA to reduce the 4 dB cable loss when NFLNA = 2.0 dB and NFBTS = 4.0 dB


References

1. ETSI, Digital cellular telecommunications system (Phase 2+), Radio transmission and reception, GSM 05.05.

2. Warren L. Stutzman, Gary A. Thiele, “Antenna Theory and Design,” John Wiley & Sons, 1998.

3. Kazimierz Siwiak, “Radiowave Propagation and Antennas for Personal Communications,” Artech House, 1998.

4. J. Lempiäinen, M. Manninen, ”Radio Interface System Planningfor GSM/GPRS/UMTS,” Kluwer Academic Publishers 2001.

explain m04 - 1 configuration planning

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