dual band networks

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imagination into opportunity Motorola Confidential ProprietaryMotorola Confidential Proprietary Feb 02 Slide 1

EMEA Systems Integration Program Review

GTSS Customer Solutions Grou

Dual Band Networks

February-2002Sherif Bahieg


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Outline

Introduction

Propagation Overview Fading Effects

Link Budget Calculations

Mast Head Amplifier

Antenna Types Losses in 900 vs. 1800

Planning aspects

Implementation Dual BTS

Single Band BTS

Different RF equipment

Parameters and Features (ALM)

Statistics Overview


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Introduction

Enables a single NetworkOperator with licenses intwo or more frequencybands to support the useof Multiband mobiles in allbands of the licenses

DCS 1800

Macrocells

GSM 900Macrocells

Example

Definition

GSM 900 to DCS1800 transparent handovers


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Introduction (cont ..)

Why Dual Band ?

Increasing Capacity

Improving Grade of Service

Relieving Congestion

Advanced Network Management Techniques

Improved Multi-layer Network


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Dual Band Mobiles Share ?

0%

5%

10%

15%

20%

25%

30%

35%

J-99 F-99 M-99 A-99 M-99 J-99 J-99 A-99 S-99 O-99 N-99 D-99 J-00 F-00 M-00

Dual_Band mobiles


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What are the Requirements?

RF considerations

Hardware considerations

Antenna and feeders considerations

Features and Parameters study


7/57imagination into opportunity Motorola Confidential ProprietaryMotorola Confidential Proprietary Feb 02 Slide 7



Propagation Overview

Fading Effect

ServingSite

DistantSite

Higher pathloss at1800 MHz

Half wavelength at 1800 MHzFading rate twice as fast as 900MHz

1800 radio wave

Reduced interference fromdistant site at 1800MHz

More aggressive reuse patterncan be achieved

Diversity systems become moreimportant especially for slowmoving mobiles





Propagation Overview (cont ..)

Antennas

Different Antenna Types

Different antenna for each Band

Dual antennas with four ports

Dual Antennas with 2 ports (900and 1800 are multiplexed )






Antennas

2 Ports Antennas

Extra Duplexers will be needed tosplit 1800 signal from 900 signal

Duplexers will be with differentpolarization to maintain diversity

900/1800

GSM 900

indoor or outdoor

Horizonmacro

dual banddiplexer

feeder

dual banddiplexer

Tx/Rx Rx

GSM 900

indoor or outdoor

Horizonmacro

Tx/Rx Rx






Antennas

GSM 1800

indoor or outdoor

Horizonmacro

900

1800

Tx/Rx Rx Rx

GSM 900

indoor or outdoor

Horizonmacro

Tx/Rx

4 Ports Antennas

No need for extra Duplexers will beneeded to split 1800 signal from900 signal

Duplexers will be with differentpolarization to maintain diversity






Antennas

Preferred antennas: 65 sector antennas

Small vertical beamwidth 30 dB

Maximum gain Low upper sidelobe (high sidelobe suppression) typ. -20 dB maximum

Dual-polarisation (slant +45/45, isolation >30 dB)

Electrical downtilt






Possible rules to select proper feeder:

GSM900 cells with 7/8 feeder, GSM1800 cells with 15/8 feeder

all cells with 7/8 feeder- when feeder loss for 1800 cells will be higherthan e.g. 3dB thicker cables will be used

all cells with 7/8 feeder- for GSM1800 cells with high feeder lossMasthead Amps are used

~ 50% more loss at GSM1800

Make

BrandModel Size dB/100m

900MHz

dB/100m

1800MHz

Impedance Max f (MHz) Bend radius(mm)

Weight(Kg)

EUPEN 5228 7/8" 3.93 5.92 50 5300 120 0.59EUPEN 5438 1 5/8" 2.41 3.71 50 2800 300 1,50

Attenuation

Feeders






Path Losses in 900 vs. 1800

A little physics

Diffraction loss and Penetration loss higher in 1800 MHz band

6dB minimal theoretical difference (see: Friis transmission formula)

Path loss difference - on-street Path loss at 1800MHz is typically 6 - 12 dB higher

Most probable difference in urban environment: 8 dB

Difference is nearly distance-independent (fixed), in typical urban cells ( i.e.

constant offset in loss per length unit )

Actual difference depends on site configuration like antenna height andantenna characteristics

Cell radius at 1800 MHz typically 50% less compared to 900 MHz







Path loss difference - in-building

Additional attenuation at 1800MHz when penetrating into buildings

High dependency of penetration loss on building structure, window size, floorheight, angle of incident waves and floor level

Empirical measurement results

Building penetration loss at 900MHz:

5dB to 25dB

Average additional path loss at 1800MHz:

7dB, 4dB standard deviation







Receivelevel

(dB)

Log (Distance)

LOS dominates Non-LOS dominates~ 150m - 300m

GSM 900

GSM 1800

>8 dB

6 - 8 dB

in typical urban cells: difference is nearly distance-independent

prerequisite: same ERP on both bands equal antenna pattern







Practical difference in coverageDifference can be compensated with a higher ERP at the1800 band

Antenna height has high impact on difference in

coverage (Diffraction - the main propagation mechanism- becomes less important)

Antenna pattern - especially vertical pattern - has highimpact on difference in coverage

Difference raises with raising cell radius

Increase sensitivity of BTS






Planning aspects

Optimisation process:

Comparing predictions of appropriate GSM900 and GSM1800 cells for in-building coverage level

(e.g. -68 dBm at 900Mhz / -61 dBm at 1800MHz)

Adjusting GSM1800 antenna tilts to obtain similar footprint compared to theappropriate GSM900 cell

Good overlapping needed to achieve efficient traffic relief on GSM900

Supports introduction of new multi-band features like co-incident multi-band handoveror single BCCH

Same coverage conditions (except fairly fixed offset) can be achieved easilywith dual band antennas

Reducing Combining stages in the DCS cells to reduce the losses and use aircombining instead.






Planning aspects

Example: separate antennae for both bands Downtilt difference between GSM900 & GSM1800 (Tilt 900 - Tilt1800)

Typically 1 lower downtilt on GSM1800

Tilt difference (GSM900 - GSM1800)

0

20

40

60

80

100

120

140

160

180

200

-5 -4 -3 -2 -1 0 1 2 3 4 5

numberofcells






Planning aspects

basic cell radiusEstimated Cell Radius with either Combinations

Distance

increasedTx power

improved

Sensitivity

transmit power base station sensitivity






Planning aspects

Environment

cell radius cell radius

@900MHz @1800MHz

rural 5150 m 2010 m

urban 800 m 250 m

ERP 55dBm

MS Rx sensitivity -102 / -100dBm

penetration loss 900MHz 20dB

additional loss 1800MHz 5dB

fading margin 6dB

interference margin 5dB

antenna / body loss 3dB

max. path loss 123dB / 118dB

antenna height: 30 m

level in build. -88dBm / -86dBm

level on street -68dBm / -61dBm

Cell Size Comparison






Planning aspects (GSM Signal Strength)






Planning aspects (DCS Signal Strength)






Mast Head Amplifier

Without MHABTS System Sensitivitydepends on L

With MHABTS System Sensitivity isalmost independent of L

L = feeder loss

S/N

S/N

Use of MHA overcomes the deterioration in thesystem sensitivity due to lengthy RF feeder cables


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Mast Head Amplifier

More Air Time

reduced interferencebetter uplink qualityincreased capacity

low handset transmitting power

longer battery life

high signal-to-noise ratiohigh voice quality

overcomes high feeder loss


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Mast Head Amplifier

with MHA

without MHA

Uplink Rx Quality

0 1 2 3 4 5 6 7

80

85

90

95

100

P

robability(%)

Measured Call Quality cumulative distribution - CDFComparison with and without MHA


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Link Budget for Motorola

HORIZONmacro

GSM 1800

no Mast Head Amplifier

air combining

[2] lognormal shadowing with 7dB standard deviation

[3] sensitivity measured at top of rack

[1] max. TCU Tx power 45.10dBm with TDF

Downlink (BTS to MS) Uplink (MS to BTS)

TCU Tx power [1] 45.10dBm MS Tx power 30dBm

Combining loss 0dB

Duplexermax_tx_bts=2 4dB

Total Tx power

@ top rack 41.10dBm

Feeder loss 3dB

BTS antenna gain 19dBi MS antenna gain 0dBi

Total EIRP 57.10dBm Total EIRP 30dBm

MS Rx Sensitivity -100dBm BTS antenna gain 19dBi

MS antenna gain 0dBi Diversity gain 3dB

Fading margin 6dB Feeder loss 3dB

(90% coverage [2]) BTS Rx Sensitivity [3] -108.5dBmFading margin 6dB

Interference margin 3dB Interference margin 3dB

Antenna/Body loss 3dB Antenna/Body loss 3dB

max. pathloss 145.10dB max. pathloss 145.5dBLink balance

(downlink - uplink) -0.40dB


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[2] lognormal shadowing with 7dB standard deviation

[3] sensitivity measured at antenna connector

[1] max. TCU Tx power 45.1dBm

Link Budget for Motorola

HORIZONmacro

GSM 1800

with Mast Head Amplifier

air combining

Downlink (BTS to MS) Uplink (MS to BTS)

TCU Tx power[1] 45.10dBm MS Tx power 30dBm

Combining loss 0dB

Duplexer MS antenna gain 0dBi

Total EIRP 30dBm

Total Tx power

@ top rack 45.10dBm BTS antenna gain 19dBi

Feeder loss 3dB Diversity gain 3dB

BTS antenna gain 19dBi Feeder loss 3dB

Total EIRP 61.10dBm MHA gain 12dB

MHA noise figure 2dB

MS Rx Sensitivity -100dBm Overall noise figure 2.56dB

MS antenna gain 0dBi

Fading margin 6dBBTS Rx Sensitivity[3] -110.4 dBm

(90% coverage [2])Fading margin 6dB

Interference margin 3dB Interference margin 3dB

Antenna/Body loss 3dB Antenna/Body loss 3dB

max. pathloss 149.10dB max. pathloss 150.23dBLink balance

(downlink - uplink) -1.13dB

max_tx_bts=0 0dB

TDF


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Implementation

RF Equipment

M-Cell equivalent: TCU

All connections blind-mate, exceptTx and test

All radios delivered with SMA-SMATx cable

Output power (top of cab): 32W(1800), 40W (900) - same as TCU

SMB Rx connections

D-type data +power connection

SMA Tx connection

Test connection

RF Block CTU


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Implementation (cont.. )

RF Equipment

Sectorised Unified Receiver Front-end

M-Cell equivalent: IADU+3xDLNBs

Six antenna connections (3 sectors,diversity receive)

Two extension ports

Extension ports permanently connectedto Rx0A and Rx0B

2B 1B 0B 2A 1A 0A AB

Programmable Switching

Rx Ext

SURF Module (Single Band)


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RF EquipmentSURF Module (Dual Band)

2B 1B 0B 2A 1A 0A AB

Programmable Switching

Extension

0A0B

1800

frequency

900

frequency 900 Dual Band module has 3 sectors of

900 + 1 sector of 1800.

1800 Dual Band module has 3 sectors of

1800 + 1 sector of 900. Extension ports are permanently

connected to Rx0A and Rx0B.


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RF Equipment

Twin Duplexed Filter.

Two completely separate transmit/receivepaths.

Permits very low loss single-radio sectorsto be configured.

Transmit loss approx. 1.5dB.

Available in 900, 1800, or dual-band.

Duplexer/

Bandpass

Filter

Ant1

Tx2 Tx1

Duplexer/

Bandpass

Filter

Ant2Rx1Rx2Dual TDF


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MCell6 Case

Conversion kit to convert an existing MCell6 Indoor 900MHz cabinet toaccept 1800MHz sectors

Provides Dualband within a single MCell6 Indoor cabinet and singlelogical site

Possible Configurations

Omni-4 (900) and Omni-2 (1800)

2/2 (900) and Omni-2 (1800)

2/2/2 (900) Indoor converted to a 2/2/2 (1800)

Restriction, 2 LNAs mounted side+centre overlaps with the 900 sector,

the 1800 TCUs are limited.


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MCell6 Case

900 MHz carriers1800 MHz carriers

To IADU

TX TX TX TX TX TX

RX RXRX RX RX RX

1800MHzDuplexer

1800MHz Low Noise Amplifier

900MHz 2 input Combined Band Pass Filter

900MHzDuplexer (not shown in picture above)

900MHz Dual Low Noise Block

RX/TX RX/TX RX/TXRX/TX

M-Cell6Multiband4 (900)- 2(1800) configuration


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Horizon Case


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BSS: freq_types_allowed

mb_preference

early_classmark_sending

early_classmark_delay phase2_classmark_allowed

Cell: frequency_type

interband_ho_allowed

optinal:

band_preference

band_preference_mode multiband_reporting

MSC: ensure phase2 signalling is enabled between BSCs and/or

MSCs

Parameters and Features


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Freq_types_allowedSpecifies the frequency typesavailable to the BSS

freq_types_allowed 5

or

freq_types_allowed PGSM, DCS1800

Parameters and Features (cont .. )

BSC Parameters


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mb_preferenceEnable or disable the Multiband feature

0 Multiband feature disabled

1 Multiband feature enabledchg_element mb_preference 1 0

phase2_classmark_allowedThis parameter defines the format of the classmark parameter sent to the MSCbased on GSM phases

0 Formatted for Phase 11 Formatted for Phase 22 Formatted for Phase 2 with Multiband

chg_element phase2_classmark_allowed 2 0


BSC Parameters


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early_classmark_sending

This parameter sets and displays:

Whether the BSS will suppress the early sending of the Classmark Updatemessage to the MSC.

Whether an MS is allowed to send an early Classmark Change message

0 = disabled across both the A-interface and the Air-interface

1 = enabled on A-interface, disabled on Air-interface

2 = disabled on A-interface, enabled on Air-interface

3 = enabled across both the A-interface and the Air-interface

chg_element early_classmark_sending 3 0


BSC Parameters


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early_classmark_delay

This parameter specifies the timer that controls how long the BSS will delaysending the Class mark Update message to the MSC during Early Classmark

sending

0 to 100000 (in milliseconds)

chg_element early_classmark_delay 0 0


BSC Parameters


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frequency_type

Use this parameter to change the frequency type of a cell, or to display the cellfrequency type

1 pgsm2 egsm4 dcs18008 pcs1900


Cell Parameters

i i


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interband_ho_allowed

Changes or sets the allowablefrequencies which a cell may handover

to.

This parameter must include, at aminimum, the frequency type for thecell. For example, if the cell has afrequency_type of pgsm, then the

interband_ho_allowedparameter mustinclude pgsm as a possible destinationfrequency band for handovers

1 to 11

1 = PGSM

2 = EGSM

3 = PGSM and EGSM

4 = DCS18005 = PGSM and DCS1800

6 = EGSM and DCS1800

7 = PGSM, EGSM and DCS1800

8 = PCS1900

9 = PGSM and PCS190010 = EGSM and PCS1900

11 = PGSM, EGSM and PCS1900

chg_element interband_ho_allowed 5 cell_number= xx


Cell Parameters

EMEA S t I t ti P R i


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band_preference (optional)

Displays the frequency bands that the cell prefersto use for handovers.

Sets the destination frequency band for intercellhandovers.

1 (PGSM),

2 (EGSM),

4 (DCS1800),

8 (PCS1900)


Cell Parameters

band_preference_mode (optional)

This parameter sets and displays the method the system

uses to have a MultiBand mobile telephone use the preferredfrequency band for a given cell in the BSS

possible values are: 0,1,2,3,4,5,6



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multiband_reporting (optional)

This parameter sets and displays the number of cells of eachsupported band the system will include in the MS MeasurementReport.possible values are:

possible values are: 0,1,2,3

0 Normal reporting of the six strongest neighbour cells with knownand allowed NCC part of the BSIC, irrespective of the band used

1 Report the strongest neighbour cell in each of the frequency bandsin the neighbour cell list, excluding the frequency band of the servingcell. The remaining positions in the measurement report shall beused for reporting Cells in the band of the serving Cell.


Cell Parameters



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multiband_reporting (optional)

1 Report the strongest neighbour cell in each of the frequency bands in theneighbour cell list, excluding the frequency band of the serving cell. Theremaining positions in the measurement report shall be used for reportingCells in the band of the serving Cell.

2 Report the two strongest cellsin each of the frequency bands in theneighbour cell list, excluding the frequency band of the serving cell. Theremaining positions in the measurement report shall be used for reportingCells in the band of the serving Cell.


Cell Parameters



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Parameter which should be changed for 1800 cells:

handover_power_level = 0

ms_txpwr_max_cch = 0

max_tx_ms = 30

ms_txpwr_max_def = 30


Cell Parameters



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BPM = 0

Default operation - no band preference expressed

Multiband handovers due to normal RF causes (PBGT, RXQUAL) can still occur

BPM = 1

Attempt handover to strongest preferred band neighbour on SDCCH - TCH assignment

If unable to handover to preferred band TCH, cancel band preference bias for the lifetime ofthe current connection

Multiband handovers due to normal radio reasons may still occur


Band Preference Modes



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Do not invoke band changes on SDCCH - TCH assignment

Go to strongest preferred band neighbour when normal radio reason (or congestion relief)handover required

Preferred band neighbours take priority in the neighbour list

BPM = 3

Prioritise preferred band at SDCCH-TCH assignment AND when radio reason handovers arerequired

This is a combination of BPM 1 and 2 conditions


BPM = 2



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BPM = 4

Do not invoke band changes on SDCCH - TCH assignment

As soon as possible after TCH assignment, attempt to handover to a preferred band channel

For normal radio reason handover, also prioritise preferred band neighbours

BPM = 5

Attempt to hand to preferred band at SDCCH - TCH assignment

As soon as possible after TCH assignment, attempt to handover to a preferred band channel

For normal radio reason handover, also prioritise preferred band neighbours This is a combination of BPM 1,2 and 4



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Invoke the operation attempt to hand to preferred band at SDCCH - TCH assignment only after the cell has become congested

This is like condition 5, but triggered only when the cell is congested



BPM = 6



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Trunking Efficiency

Using Advanced Load Management or

Handover on Congestion

2 Carriers on GSM 900 and 2 Carriers on GSM 1800

Utilising Band Preference Modes1, 3, 5, 6 (band reassignment SDCCH to TCH)or Handover on Congestion(GSM900 + GSM1800 multi-layer system)

Without Load Management

2 x 8,2 Erl (14 TCH)

With Load Management

20,15 Erl (28 TCH)

Total Erl / Cell

23 % gain in trunking efficiency !

One layer has no blocking probability for Multi-band Mobiles





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Macrocell

Server

GSM1800

Layer

BPM 2 Macrocell

Neighbor

Macrocell

Neighbor

GSM900Layer

BPM 3Macrocell

Neighbor

Microcell

Neighbor

GSM900

Layer

BPM 3 MicrocellNeighbor

Imperative HOPwr bdgt HO

Serving Cell 1800 Layer

Band preference mode keeps call inimperative and PBGT handoverconditions on 1800 layer

If serving cell level drops belowthreshold => handoff to 900 layer(Type 3 algorithm)

Also Type 2 implemented

Preferred call set-up possible on 1800due to C2 cell re-selection parameter

Handover to microcell layer just inspecial cases, e.g. Indoor


Implementation Scenarios



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Macrocell

Neighbor

GSM1800

Layer

BPM 2 Macrocell

Neighbor

Macrocell

Server

Macrocell

Neighbor

Microcell

Neighbor

GSM900

Layer

BPM 3 Microcell

Neighbor

GSM900 Layer

BPM 3

Pwr bdgt HO Imperative HO

Serving Cell 900 Layer

Band preference mode moves callin imperative and PBGT handover

situations to1800 layer as first priority

On PBGT reasons 2nd priorityis microcell layer (Type 5), 3rd is the900 layer (Type 1)

On imperative reasons 2nd priority

is 900 layer, then microcell layer - alsoother way round possible

Band re-assignment to 1800 layerif call set-up on 900 layer (BPM 3)





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Macrocell

Neighbor

GSM1800

Layer

BPM 2 Macrocell

Neighbor

Macrocell

Neighbor

GSM900

Layer

BPM 3Macrocell

Neighbor

Microcell

Server

GSM900

LayerBPM 3

Microcell

Neighbor

Pwr bdgt HO Imperative HO

Serving Cell 900 microcell Layer

Band preference mode moves callin imperative and PBGThandover situations to 1800 layer

as first priority

On PBGT reasons 2nd priorityis microcell layer, no pbgt handoverto 900 layer enabled

On imperative reasons 2nd priorityis 900 layer, then microcell layer - alsoswapped priority possible

Band re-assignment to 1800 layerif call set-up on microcell layer





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Example of ALM and Handover parameter settings in a dual-band network


Database Settings Example



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Dual Band Statistics

interband_activity

This statistic will count the interband handover attempts based

on the target frequency band.

Bin Name Descriptions

0 PGSM_HO_ATMPT Record handover attempt to PGSM

1 EGSM_HO_ATMPT Record handover attempt to EGSM

2 DCS1800_HO_ATMPT Record handover attempt to GSM1800

3 PCS1900_HO_ATMPT Record handover attempt to PCS1900

4 PGSM_HO_FAIL Record handover failure to PGSM

5 EGSM_HO_FAIL Record handover failure to EGSM

6 DCS1800_HO_FAIL Record handover failure to GSM1800

7 PCS1900_HO_FAIL Record handover failure to PCS1900

8 INVALID_FREQ_ASGN Frequency not implemented for assignment

request.

9 INVALID_FREQ_HO Frequency not implemented for handover.



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ms_tch_usage_by_type

This counter array statistic will track the length of time spent on

a TCH by various types of mobiles.Duration measured in derived bymultiplying with 6 seconds.

Dual Band Statistics (cont.. )


0 MS_PGSM_ONLY Record duration of PGSM MS only

1 MS_DCS1800_ONLY Record duration of GSM1800 MS only

2 MS_PCS1900_ONLY Record duration of PCS1900 MS only

3 MS_PGSM_EGSM Record PGSM and EGSM

4 MS_PGSM_DCS1800 Record PGSM and GSM1800

5 MS_PGSM_EGSM_DCS1800 Record PGSM, EGSM, and GSM1800

6 MS_PGSM_PCS1900 Record PGSM and PCS1900

7 MS_PGSM_EGSM_PCS1900 Record PGSM, EGSM, and PCS1900



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ms_access_by_type

This counter array statistic will track the number of system

accesses by the various types of MSs.

Dual Band Statistics (cont.. )


0 MS_PGSM_ONLY Record duration of PGSM MS only

1 MS_DCS1800_ONLY Record duration of GSM1800 MS only

2 MS_PCS1900_ONLY Record duration of PCS1900 MS only

3 MS_PGSM_EGSM Record PGSM and EGSM

4 MS_PGSM_DCS1800 Record PGSM and GSM1800

5 MS_PGSM_EGSM_DCS1800 Record PGSM, EGSM, and GSM1800

6 MS_PGSM_PCS1900 Record PGSM and PCS1900

7 MS_PGSM_EGSM_PCS1900 Record PGSM, EGSM, and PCS1900

dual band networks

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