05%2E UMTS Co 2Dlocation Issue

7/29/2019 05%2E UMTS Co 2Dlocation Issue

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UMTS Co-location Issues



11

• Introduction

• Interference Analysis Methodology

• Interference Analysis Results

• UMTS operators co-existence

• Interference Prevention

— Antenna protection

— Filter(s)

• PHS interference issues

• Conclusion

Agenda



22

• UMTS comes after other radio systems

— CDMA (800, 900, 1900), GSM900, GSM1800, GSM1900

• High data rate & multi-service UMTS networks require a

high density of sites

• It becomes more and more difficult to find new sites:

—UMTS market pressure

– Available radio sites are very limited

– Quick rollout & cost reduction

—Environment protection

Introduction

Radio site sharing is one of the efficient solution



33

• Introduction






— Filter(s)


• Conclusion

Agenda



44

Interference Analysis Methodology

Spurious emissions and

intermodulationsstudy

Blocking study

Required isolationbetween GSM / UMTS

antenna connector

and UMTS antenna

connector

Antennas performances BTS performances



55

• Introduction






— Filter(s)


• Conclusion

Agenda



66

Required isolationsbased on

standard recommendations



77

Standard recommendationsRequired isolations

UMTStransmitter

to

GSM 900

receiver

GSM 900transmitter

to UMTS

receiver

UMTStransmitter

to

GSM 1800

receiver

GSM 1800transmitter

to UMTS

receiver

UMTStransmitter

to

UMTS

receiver

Blocking 40 dB 58 dB 48 dB 58 dB 63 dB

Spurious

emissionsIntermodu

lations

products

29 dB

83 dB

(32 dBwith New

Req)

29 dB

83 dB

(32 dBwith New

Req)

32 dB

: required isolations are pessimistic since no feeder losses have been taken into account



88

Required isolationsbased on

products performances



99

Physical calculations considering UMTScompetitor BTS and Nortel UMTS iBTSRequired isolations

iBTS UMTS

transmitter to

iBTS UMTS

receiver

iBTS UMTS

transmitter to

UMTS competitor

receiver

UMTS competitor

transmitter to

iBTS UMTS

receiver

Blocking 0 dB 63 dB 0 dB

Spurious

emissions

Intermodu

lations products

15 dB 15 dB 32 dB




1010

Physical calculations considering GSMcompetitor BTS and Nortel UMTS iBTSRequired isolations


iBTS UMTS Tx to GSM

Rx

GSM Tx to iBTS UMTS

Rx

Blocking 40 dB(GSM 900)

48 dB(GSM 1800)

28 dB

Spurious

frequencies 14 dB

83 dB

(32 dB if compliant withnew GSM req.)



1111

Conclusion

• Nortel iBTS UMTS:

— iBTS UMTS has better performances than the UMTS

standard recommendation

• Competitor BTS:

— If only compliant with standard recommendations,

interference problems will occur

Important to do studies considering the real

performances of the products

in order to reduce the required isolations to avoid

interference between systems



1212

• Introduction






— Filter(s)


• Conclusion

Agenda



1313

UMTS operators co-existenceUL Interference Mechanism

• Adjacent channel interference— a single mobile can have severe impact on a large number of other

mobiles

— "cell breathing" phenomenon

In Tx-UMTS Channel, MS side

Associated in Rx-UMTS Channel, BS side

1920 MHZ 1980 MHZ

UMTS FDD UL band

Capacity loss

Possible dead zones



1414

UMTS operators co- existenceDL Interference Mechanism•

Adjacent channel interference:— Smaller impact:

– Design of the BS

– Fewer users affected

In Tx-UMTS Channel, BS side

Associated in Rx-UMTS Channel, UE side

2110 MHZ 2170 MHZ

UMTS FDD DL band

Possible dead zones

Capacity loss



1515

UMTS operators co- existenceACP

ACLR

ACS

Ability of a transmitter to

confine its transmissions to

its own channel

Ability of a receiver to

exclude theinterference present

on an adjacent

channel

ACP

Sums up the degree of interaction

between adjacent channels. Combination

of both transmitter and receiver

performance



1616

UMTS operators co-existenceSolutions

Carrier spacing

Good ACLR

Co-location

SOLUTIONS

Good ACP / ACIR

Good ACS

Adjacent Channel

Leakage Ratio Adjacent Channel Selectivity

Adjacent Channel

Protection /

Adjacent Channel

Interference Ratio

Spectrum efficiency

Equipment limitations .



1717

UMTS operators co- existenceSome values of ACP from Normalisation & Nortel ACP

• Agreement between participant on the following values

of ACLR (25.101, 25.104) for FDD mode:

• The UE has less ACP due to its small size.

ACLR1

(5 MHz)

ACLR2

(10 MHz)MS 33 dB 43 dB

BS 45 dB 50 dB

Nortel ACLR & ACS = 58 dB

ACLR & ACS



1818

UMTS operators co-existenceCarrier spacing

•

For UMTS, allocated bandwidth for one carrier is 5 MHz andspacing between central frequency is 5 MHz

— With this spacing between two adjacent competitor channels (and assumingthe standard required ACP), the capacity loss is around 5%

• Idea: decrease the distance between two carriers belonging to thesame operator in order to move away from competitor’s carrier toget more protection

— 4.6 MHz spacing (intra operator) => ACP decrease of around 10 dB

— 5.4 MHz spacing (inter operator) => ACP increase of 2 dB

• Spacing of 4.8 MHz (instead of 5 MHz) between two carriers

belonging to the same operator is a good choice:— No impact on capacity (intra operator)

— Reducing the capacity loss (inter operator)

• Carrier spacing performance is linked to the design of filter

Carrier spacing



1919

UMTS operators co-existenceCo-location• Co-location means less UL adjacent channel interference due to UE

and less DL adjacent channel interference due to BS:

• But, inter BS interferences can occur:

Co-location

System B

System A

BS filterings

can reduce these

interferences



2020

UMTS operators co-existenceConclusion

• UMTS operators coexistence consequences:

— Capacity loss

— Dead zones

• Solutions:

— High ACP

— Carrier spacing:

–

At least 5 MHz between two inter-operator FDD –

FDD carriers – At least 4.8 MHz between two intra-operator FDD – FDD

carriers

— FDD – FDD base stations co-location



2121

• Introduction






—Filter(s)


• Conclusion

Agenda



2222

Co-siting radio solutions

Wideband

Noise

Spurious

emissionsIntermodulations

Blocking

Co-siting solutions

BTS radio

performances

Filters

BTS antennaAntenna decoupling

Antenna isolation

Antenna rejection



2323

Main solutions

• Antenna protection

• External filter(s)

— External filter at Tx BTS sidefor reducing Tx out-bandspurious and widebandnoise transmission

— External filter at Rx BTS

side for protecting out-bandof Rx band and improvingthe Rx blocking performance

Interference Prevention

System A

BTS

System

B BTS

Antenna

decoupling



2424

Main Solutions With antenna decoupling, required additional decoupling (dB) is

Requ ire isolat ion (dB ) – Rx cable loss (dB ) – Tx cable loss

- An tenna decoupl ing (dB)

If addit ional decoup l ing 0 OK !

If addit ional decoup l ing > 0 Filter(s) are needed !


System A System B

PA

Combiner

PA

Combiner

RxLev RxLev

Decoupling

Cable Loss Cable Loss

TxPATxPA



2525


Antenna protection

• Antenna separation decoupling : – attenuation between two antennas when

separated (between the two connectors) for a

given frequency band

– depends on antenna performances and site

configuration

• Antenna rejection :

– attenuation of a signal fed into an antenna

working in another band

•Antenna isolation : – Attenuation of a signal between the

transmitting antenna connector and the

reception antenna connector



2626

Antenna decoupling

Two separated antennasVertical separation between antennas

• 1 mast per sector

• 1 UMTS antenna

• 1 antenna of other system

• Isolation is reached:

— by vertical separation between antennas

other BTS

UMTS

iBTS

Antenna

decoupling



2727

Antenna decoupling

Two separated antennasHorizontal separation between antennas

• 2 masts per sector

• 1 UMTS antenna

• 1 antenna of other system


—by horizontal separation between antennas

other BTS

UMTS

iBTS

Antenna

decoupling



2828

Antenna decoupling

Two separated antennas

example

• 1 X-polar antenna of other system

— 2 ports

• 1 UMTS X-polar antenna

— 2 ports

• 4 feeders per sector

Other systemUMTS

BTS

UMTS

Feeder

Cables

Other

BTS



2929

Antenna decoupling

Antenna 2

Antenna 1

Signal

generator Input

S

S’

Network analyser

Antenna decoupling measurement

between GSM 900/1800 X-

polar directives antennas and

UMTS X-polar directive

antenna



3030

with horizontal separation

0.5 to 4m

Antenna decoupling

d

GSM X -polar antenna

UMTS X -polar antenna

Average S' in UMTS band =0 deg

-90 -80 -70 -60 -50 -40 -30 -20 -10

0

0 1 2 3 4

Horizontal distance in m

S ' i n

d B

GSM-900 antenna

GSM-1800 antenna

Dual (GSM-900)

Dual (GSM-1800)

Average S' in UMTS band =60 deg

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10

0

0 1 2 3 4


S ' i n

d B

GSM-900 antenna

GSM-1800 antenna Dual (GSM-900)

Dual (GSM-1800)



3131

Antenna decoupling

d dB

GSMX-polar antenna

UMTSX-polar antenna

Antenna decoupling versus

horizontal separation betweenantennas

• Antenna GSM 900

—d = 0.5 m = 65 dB

—

d = 3 m = 76 dB

• Antenna GSM 1800

—d = 0.5 m = 57 dB

—d = 3 m = 68 dB

• Antenna GSM dual band 900 / 1800

—d = 0.5 m = 62 dB (Tx 900) / 55dB (Tx 1800)

—d = 3 m = 75 dB (Tx 900) / 67 dB(Tx 1800)



3232

• Antenna decoupling with vertical separation

Antenna decoupling

D

UMTS

X-polar antenna

GSM X-polar antenna Average S' in UMTS band

Same azimut

-100.00

-90.00

-80.00

-70.00

-60.00

-50.00

-40.00

-30.00

-20.00

-10.00

0.00

0 0.5 1 1.5 2 2.5 3 3.5

Vertical distance in m

S ' i n

d B

GSM-900 antenna

GSM-1800 antenna

DUAL (GSM-900)

DUAL (GSM-1800)



3333

D

dB

UMTSX-polar antenna

GSMX-polar antenna


vertical separation between

antennas

• Antenna GSM 900

—

D = 0.5 m

= 72 dB — D = 3 m = 81 dB


— D = 0.5 m = 54 dB

— D = 3 m = 65 dB


— D = 0.5 m = 65 dB (Tx 900) / 60 dB(Tx 1800)

— D = 3 m = 70 dB (Tx 900) / 66 dB (Tx1800)

Antenna decoupling



3434

Antenna decoupling with Horizontal/vertical separation

Antenna decoupling

UMTSX-polar antenna

GSMX-polar antenna

D

d

Average S' in UMTS band

d=1.5m

Same azimut

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

0 0.5 1 1.5 2 2.5 3 3.5 4


S ' i n

d B

GSM-900 antenna

GSM-1800 antenna

Dual (GSM-900)

Dual (GSM-1800)



3535

Antenna decoupling


vertical and horizontalseparations between antennas

• Antenna GSM 900

—d = 0.5 m = 70 dB

—d = 3 m = 85 dB


—d = 0.5 m = 60 dB

—d = 3 m = 71 dB


—d = 0.5 m = 70 dB (Tx 900) / 60 dB

(Tx 1800)

—d = 3 m = 75 dB (Tx 900) / 72 dB

(Tx 1800)

UMTSX-polar antenna

GSMX-polar antenna

D

d

D = 1.5 m

Antenna decoupling versus azimuth



36

36

Antenna decoupling versus azimuthdivergence between antennas

• Horizontal separation

with azimuth divergence

• Vertical separation with

azimuth divergence

d

GSM

Antenna

UMTS

Antenna

d

UMTS

Antenna

GSM

Antenna

d = 0.5 m

= 30°

d = 0.5 m = 90°

55 to 60 dB (1800)

65 to 70 dB (900)

60 dB (1800)

70 dB (900)

Antenna decoupling between two UMTS



37

37

Antenna decoupling between two UMTSantennas versus horizontal or verticalseparation

• Vertical separation: • Horizontal separation:

75 dB D

dB

UMTS X-polar antenna

UMTSX-polar antenna

d dB

UMTSX-polar antenna

UMTS

X -polar antenna

d = 0.5 m

d = 0.5 m 55 dB

d = 3 m 70 dB 85 dB

d = 3 m



38

38


• If antenna protection does not bring enough

isolation, filters can be added

— two separated antennas, physical separation and possible

filters

—one single antenna: dual band antenna, filters

—diplexer / triplexer whatever the type of antenna



39

39

Example: two separated antennas -

Vertical separation• 1 mast per sector

• 1 UMTS antenna

• 1 GSM antenna

• Isolation is reached:— by vertical separation between antenna

— with filter at GSM side if antenna decoupling isnot sufficient

GSM Nortel

BTS

UMTS

iBTS

Antenna

decoupling

Co-location solutions example



40

40


Example: Two separated antennas

Horizontal (and/or vertical)

separation(s) between antennas

• 2 masts per sector

• 1 UMTS antenna & GSM antenna


— by vertical and horizontal separations between

antennas

— with filter at GSM side if antenna decoupling is

not sufficient

GSM Nortel

BTS

UMTS

iBTS

Antenna

decoupling



41

41


GSM Nortel

BTS

UMTSiBTS

Example: One single dualband antenna


• 1 GSM / UMTS dual band antenna

•

Isolation depends on antennaisolation between GSM and UMTSbands

— dual band antenna characterised byabout 30 dB of isolation between thedifferent bands

— filter at GSM side may be necessary

30 dB (typical value)

between GSM band

and UMTS band



42

42

Example : Use of diplexer or

triplexer


• Isolation is reached with diplexer or

triplexer, which corresponds to actually

two or three filters:

— filter(s) at GSM side

— filter at UMTS side

• Whatever the type of antennas

— Wideband antenna

— dual band antenna / Triband antenna

— Monoband antenna

GSM Nortel

BTS

UMTS

iBTS

Diplexer


Antennas options



43

43

Antennas options

• 2 vertical antennas for each band

— 4 antennas per sector

—

Space diversity

• 2 vertical dual band antennas


— Heavier antenna

— Space diversity

• 1 dual band cross polar antenna — 1 antenna per sector

— Cross polar diversity

• 1 cross polar antenna for each band


— Cross polar diversity

• Measurements and simulations show that Xpolar diversity (0.7 correlationfactor) give a very good Eb/N0 gain. 1 antenna / sector is more suitable for Urban environments. 1.5 dB insertion loss

Dual Band antennas can be used on ly

i f equ ipped w ith independent electr ical

t i l t systems .

Feeders options



44

44

p• Independent feeders /

independent antennas

• Shared feeders /

Shared antenna

DCS1800

BTS

UMTSiBTS

Duplexer Duplexer

Duplexer Duplexer

X-polar

Dual Bandantenna

• Shared feeders /

Independent antennas

DCS

1800

BTS

UMTSiBTS

X-polar

UMTSantenna

DCS1800

BTS

UMTSiBTS

Duplexer Duplexer

Duplexer Duplexer

• No reuse of 2G aerials

• New Feeders for UMTS

• New antenna for UMTS

• Site capacity ??

• Reuse of 2G feeders

• New antenna for UMTS

• Need additional feeder if

2G without diversity

• Reuse of 2G feeder

• Reuse of 2G antenna if X-

polar. Or 1 single new

antenna for both systems

Shared feeders using external Duplexer



45

45

Shared feeders using external Duplexer

• Physical implementation (without diversity)

External

duplexer

Option al Cabin et area

for Low er duplexer shared

feeder

The external duplexer can be

associated with TTLNA (Tower Top

Low Noise Amplifier) for UMTS only

or for both UMTS and DCS 1800

Typical insertion loss for both

internal and external duplexer :0.5 dB. No impact on Link Budget

GSM 1800 path UMTS path

Frequency 1710 to 1880 MHz 1920 to 2170 MHz

Insertion loss (dB) 0.5 0.5

Return loss antenna port (dB) 18 18

Attenuation in GSM 50 50

Attenuation in UMTS 50

IMD 3rd order (dBc) -160 -160

Max Tx Power (W) 200 200

Duplexers provide necessary f i l ter ing

(isolat ion) between UMTS and GSM

Use of TTLNA (Tower Top Low Noise Amplifier)



46

46

( p p )

• The TTLNA is used to increase the coverage of the cell by compensating

the feeder loss.

• It can be incorporated with the external duplexer, and provided only for

the UMTS path or for both paths.

DCS

1800

BTS

UMTS

iBTS

Duplexer Duplexer

X-polar

Dual Band

antenna

Duplexer

TTLNA

Duplexer

TTLNA

The impact on the Link

Budget is a 3 dB

increase of the reverse

path loss. Thiscorresponds to the

compensation of the

feeder loss. DCS

1800

BTS

UMTS

iBTS

X-polar

UMTS

antenna

TTLNATTLNA



47

47

• Introduction






—

Filter(s)


• Conclusion

Agenda

C l ti b t PHS d UMTS



48

48

Co-location between PHS and UMTSBase Stations• Wideband noise

— The frequency separation between the PHS band ([1905~1915MHz]) and theUMTS Uplink band ([1920~1980MHz]) is very small

— PHS maximum power corresponds to wideband noise of -22 dBm for a 5 Mhzband

— Required isolation is 96 dB

• Spurious emission

— PHS out of band spurious emission required to be less than 2.5 W –

correspond to a -26 dBm threshold in 5 Mhz UMTS band— PHS in band spurious emission required to be less than 250 nW – correspond to

a -36 dBm threshold in 5 Mhz UMTS band

— Required out of band isolation is 92 dB, required in band isolation is 16 dB

• Blocking

— PHS base station maximum transmit power is 2 W – correspond to 33 dBm


Solution

• 50 dB out of band filtering at PHS base station output and physicalseparation of antennas


PHS B St ti I t f i ith UMTS



49

49

PHS Base Stations Interfering with UMTSMobiles• Wideband noise

— The frequency separation between the PHS band ([1905~1915MHz]) and the UMTSDownlink band ([2110~2170MHz]) is large enough

• Spurious emission— For out of band spurious, maximum tolerated interference level at the mobile side in the

UMTS band is –116.5 dBm

— For in band spurious, the minimum requirement gives a maximum power for the adjacentchannel interfering signal on receive at the UMTS mobile of –52 dBm

— Required out of band isolation is 90.5 dB, required in band isolation is 16 dB

• Blocking— The required blocking level for Downlink band in UMTS is –15 dBm


Solution

• PHS signal has high pathloss, usually providing enough isolation• Additional isolation is required only in the worst case scenario when

PHS base station is very close to an UMTS mobile but far from thePHS mobile


PHS M bil I t f i ith UMTS



50

50

PHS Mobile Interfering with UMTSInfrastructure• Wideband noise and Spurious emission

— PHS specifications for base station and terminal are the same except maximum transmitpower

— Wideband noise and spurious emission discussion above remains the same

— Worst case isolation required is 96 dB

• Blocking— The required blocking level for Downlink band in UMTS is 10 dBm

—

Required isolation is 25 dBSolution

• PHS signal has high pathloss, usually providing enough isolation

• Additional isolation is required only in the worst case scenario whenPHS terminal is very close to an UMTS base station. Presumably theprobability is low.


PHS M bil I t f i ith UMTS M bil



51

51

PHS Mobile Interfering with UMTS Mobile

• Wideband noise and Spurious emission— PHS specifications for base station and terminal are the same except maximum transmit

power

— Wideband noise and spurious emission discussion above remains the same

— Worst case isolation required is 90.5 dB

• Blocking


Solution

• PHS signal has high pathloss, usually providing enough isolation

• Additional isolation is required only in the worst case scenario whenPHS terminal is very close to an UMTS terminal. Presumably theprobability is low.



52

52

•UMTS is an interference limited system—The interference must be minimized in the network design phase

in order to optimize coverage and Capacity

• Radio sites co-location brings interference

• Co-location solutions exist—BTS performance (Tx/Rx filters)

—Antenna decoupling with space separation (H/V)

—Antenna isolation with multi-band antenna

—External filters at BTS sides (Tx BP filter and Rx BP filter)

Conclusions



Documents

05%2E UMTS Co 2Dlocation Issue