Indoor Coverage

Indoor Coverage Solutions

V. Merle RF Solutions Engineer  GSM Solutions 06/17/99

Indoor Solutions Objectives

Indoor Market  includes a wide range of  applications for operators

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Indoor Solutions Objectives

Indoor Market  includes a wide range of  applications for operators

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 Agenda • Indoor Coverage Solutions  – Indoor Solutions approaches  – RF distribution System

• Indoor Radio Dimensioning • Corporate Coverage Specificity • Indoor Design Process Outlines • Indoor Realizations  – Example : Corporate Coverage with PicoNode

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Indoor Coverage Solutions

Which Indoor  Solution ? 

Source

? 4

Macrocell & Indoor Application

Macrocell  Densification

• Indoor coverage improvement, especially for  higher floors

• Difficulty to get perfect indoor coverage, especially for low floors, underground parking & deep indoor  • No extra capacity extension if not taken into account from the start

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Microcell solution

• Good coverage solution, especially for  lower floors • High capacity solution • High spectrum efficiency Higher sites density 

• High density of sites higher cost • Problem of dimensioning the macro/micro cell in order to cope with building generated traffic • Localized solution Macro • Problem of atypical areas µ

cell

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Repeater solution Extension of the outdoor  coverage coming from a macro/micro cell 

• Coverage everywhere in indoor areas • Fast & low cost solution

• No extra capacity Possible overload of the serving cell • Limited power solution • Possible BTS blocking & BTS desensitivity Fine tuning of repeater amplifier gains 7

Picocell solution

Dedicated cells for the considered  buildings

• Coverage everywhere in indoor areas • Capacity extension into indoor areas • Highest spectrum efficiency

• Higher design load : specific design for  specific building

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Indoor System Repeater 

Indoor  Objectives - Good coverage - Good quality  - Traffic capture * DAS

2 key points - BTS source - RF system

BTS

RF system

DAS : Distributed Antenna System

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Indoor Issue Indoor Objectives Good coverage Good quality Traffic capture

 Indoor/Outdoor Interference

How to Integrate the Indoor cell  in your  Network ?  - in terms of  interference - in terms of  traffic capture - in terms of  Handover 

 Indoor cell resurgence

 Field strength Competition Outdoor cell

Indoor cell

Maximize Indoor field strength, Minimize Outdoor leakage 10

RF Distribution System Repeater & Picocell  solution specific 

Coaxial cable • + Antenna • + Leaky feeder 

Distributed   Antenna System • Optic Fiber DAS  • CATV  • Coax + Power   Amplifier 

Distributed Base Stations (DBS)

System choice depends on :

• Building form & size • Required capacity/coverage/quality  • Available spectrum • Installation constraints • Reuse of existing infrastructure • Resources constraints • Cost  11

Indoor RF system Existing  infrastructure Confinement  request 

• Coaxial feeder (antenna / leaky cable) — widely used solution — large band system — low hardware cost — installation constraints and costs

• Optic Fiber System (DAS) Interference competition 2 Main Technologies

— new technology — possible optic infrastructure reuse — high hardware cost — low installation cost & constraints — low EIRP distributed antenna approach

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Coaxial cable + Antenna

— Expectation of high EIRP — Wide area to cover 

Sufficient power  to guarantee antennae EIRP & compensation of  feeder losses

Careful attention on source  position to ensure coverage over  targeted area

— For small building coverage (3-5 floors) or small distribution distance (100 m)

— Localized source : careful attention on proximity of apertures to minimize outside leaking — Limited deployment system — Installation constraints

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Coaxial cable + Leaky feeder 

— For small building coverage (3-5 floors) or small distribution distance But no strong  signal … Jammer  overcome ? 

— Homogeneous indoor coverage — Very low outside radiation application — Good confinement possibility

New solution : Flat Strip Radiax 

— Installation constraints

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Optic Fiber System (1)

• Various OEM Fiber distributed antenna solutions — Monomode Use of fiber  optic cables for  signal  distribution

— Multimode

• Nearly identical RF performances • Best solution criteria : — material & installation cost

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Optic Fiber System (2) — Low-loss low-noise fiber optics transceivers for signal conversion — For huge building (> 5 floors) & wide distribution distance (1-2 km) with no attenuation

 Appropriate In-  building  coverage for  scattered  buildings

— Possible infrastructure reuse — Low installation cost and constraints  –  –  –  –

ease of installation small discrete flexible cable no bulky feeder trays required minimal disruption to functions or staff 

— Low output power & same low EIRP for all connected antennas — Critical deployment speed — Higher hardware cost

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Indoor Radio Dimensioning 

How to dimension the Indoor network ? 

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Indoor Solution

2 dimensioning points - Capacity  - Coverage

• Build your Indoor solution considering : — Capacity needs

 t ySpectrum availability  i—  c  a  C a p — Frequency Planning — Quality of Service — Coverage requests

 n   g  i Interference control —  s  e  d  R F — Building architecture — BSS features

BTS & RF system

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Capacity dimensioning  • Repeater / BTS Constraints Who is the targeted user?  Which quality of  service ? 

— Traffic needs & capacity evolution — Spectrum availability — Possible frequency planning — Power requirement issues — Installation issues

• Nortel Networks Solutions What spectrum can be used? 

Capacity solutions First input for  RF design

Power solutions

• Small Capacity :

• Low Power :

• 2 TRXs S2000L / H • up to 3 TRXs Corporate Piconode & distributed pBTS portfolio • High Capacity : S8000

• 2W & 8W Piconode BTS • 2.5W S2000L • High Power : • 24W S2000H • 30W S8000 19

Frequency Plan • Spectrum reuse

High spectrum efficiency   possibility 

— 3 dimensional frequency planning — by floor  — from floor to floor 

MA1 MA2

• Fractional reuse

— MAIO / HSN allocation per building / floor 

Three dimensional frequency planning

Frequency  Hopping 

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Spectrum sharing  1 single band  for the whole network  Outdoor + Indoor  Nortel  solutions: BCCH plan  AFP  TCH plan Fractional reuse

• Single band for outdoor and indoor  Outdoor

µ

cell

Indoor

Whole spectrum for the network 

Is there dedicated spectrum for indoor, how much ?

• Designing indoor radio network with spectrum constraints  – Careful borrow from distant macro cells for indoor  frequencies  – Efficiency of the coverage confinement

Spare frequencies for indoor 

• Optimized outdoor spectrum utilization can save some spare frequencies for indoor design 21

Design Constraints

• Installation constraints — Accessibility — Distributed system : feeder runs, feeder trays … — Antenna type (omni, panel, …)

• Minimize Cost — Equipment : BTS system, feeders, splitters, antennas, connectors, amplifiers, … — Installation — Maintenance (distributed system, active elements, …) — Transmission / Power, equipment room (leasing)

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Corporate Coverage Specificity 

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Indoor Operator Approach • Corporate Service Offer  — Commitments on QoS for a specific end-client

Operator  interests

— Deskset / gsm mobile interoperability — Dedicated sub-network — PBX like Services

One solution dedicated to one building 

• Corporate Coverage — High quality of Coverage / QoS Improvement — Good voice quality — Traffic Capture — Part of PLMN Network Extension / Optimization

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Corporate Coverage Specificities • Type of customers (operators, building owner, company representatives, …)

• Specific Corporate environment • High QoC & high QoS expected : corporate coverage should be optimum

• Capacity availability — Specific subscriber : high penetration rate (~ 50%) — Specific corporate call profile

• Specific features : — dialing plan, specific billing, PBX extension, supplementary services, data ...

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Indoor Design Process Outlines

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Indoor RF Design Process 2 Strategies : • Careful design Measurements mandatory  • Fast design only  Optimization

Cooperation needed with : • Building  owner  • Site engineer  • I&C team

 a s e  h  P  s  i s i t e  u  q    e  P r e r

1- Customer  requirements 2- RF prerequisites

RFM Measurements & Site survey 

3- BTS / Repeater  choice

 h a s e  P  n  e s i g   D  F  R 

4- RF design 5- RF validation

 a s e  h  P  t  n  y m e   o  l  p  D e  m   e  t  s  S y

RFM Measurements Simulations I&C 

7- System deployment

8- System validation

* Example for 3-5fl buildings

RSV Measures

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Indoor realizations

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Example 1 : Coax + Antenna Downlink 

Uplink 

BTS parameters

34 dBm

-104 dBm

Hybrid coupler 

3 dB

Jumpers

1 dB

Coax

2*1:2 splitter 

6 dB

Splitter 

50 m coax cable + connectors 6 dB

Solution widely used in HK, Singapore,..

S2000

Antenna

3 floors building, S2000L

2dBi antenna

2 dBi

RF Distribution loss

13 dB

Slow mobile margin

6 dB

Body loss

3 dB

Mobile antenna gain

2 dBi

Mobile parameter 

33 dBm Downlink 

Uplink 

Worst Link budget

112 dBm 112 dBm

115 dBm limited Downlink

Indoor minimum field

-91 dBm

 propagation attenuation : 11.5 dB/100m

EIRP antenna #1

23 dBm

 Limiting point  : RF distribution loss

EIRP antenna #2

20 dBm

EIRP antenna #3

19 dBm

Design Threshold

-78 dBm

• 7/8“ foam coax cable  propagation attenuation : 4.2 dB/100m

• 1/2” superflexible coax cable

13 dB (50m 1/2 ’’ + 2 splitters)

Total Link 

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Example 1 : Coax + Antenna Solution used in UK, Singapore

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2 -3 dB

19.5 dBm

-1 dB

3 -3 dB

-1 dB

-1 dB

Splitter 1*2

BTS S2000L

-1 dB

Antenna -1 dB

Antenna location - EMC risks - MPE limits - Blocking

29.5 dBm (-10) 14.5 dBm

10.5 dBm

10.5 dBm

Bidirectional amplifier/ repeater  for huge deployment scale Power splitter  usual or directional

Amplifier gain to be tuned carefully Impact on Noise figure and sensitivity

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Example 2 : Corporate Coverage with PicoNode

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Corporate Offer  • NORTEL provides a dedicated Corporate approach with PicoNode ensuring one local GSM Switching with PBX connection to provide one unique solution to end-users.

• This solution is somehow equivalent to one Combo : MSC/BSC/BTS  in one box 

small sized GSM system as it integrates MSC, BSC & some BTS in one really compact system.

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Corporate Coverage with PicoNode specificities (1) • Picocell traffic management — The objective is to save some resources of the picocell; nonCorporate subscribers must be directed to the macrocellular  network.

Future effective solution [R6] : SOLSA

— Need for “better field strength” approach implying accurate RF design & tuning  – careful attention on frequency plan change  – careful attention on new BTS introduction

• HO characteristics — Handover facility requested to ensure a seamless service at entrance points. — No HO Ping-Pong between the Picocell & the Macrocell.

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Corporate Coverage with PicoNode specificities (2) • Frequency sharing 2 key points

— Leakage issues  – from “no specific attention” to “no field radiated outside”

specific requests of radio thresholds : highest limit for  outside radiation (e.g. -90 dBm@50%)

• Leakage • Spectrum

— Spectrum issues  – dedicated spectrum or reuse of some spectrum used outdoor macrocells :

number of frequencies = number of TRXs

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Piconode Datafill Parameters Setting (1) • Favor selection & reselection towards the PicoCells : same celltype as PLMN  cells

2 users types (public & hybrid)

Piconode network for all mobiles entering in the corporate building  – RxLevAccessMin(pcells) 90% (12dB)

• Link Budget

Leaky feeder input power

20 dBm

End Leaky feeder power

9.5dBm

Design Threshold

-73dBm

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LGC Distributed Wireless Access • Main Hub • Up to 4 Expansion Hubs • Multimode fiber up to 1Km • +10 dBm maximum input power for O1 • +7 dBm maximum input power for O2

Expansion Hub    r   e     b     i     F

 e r   F  i  b

U T P  o r S T  P 

Expansion Hub U T P  o r S T  P 

Coax

Fiber Main Hub F i b er   

pBTS • 1 FMH per pBTS

Expansion Hub U T P  o r S T  P 

F    i    b  e   r   

Expansion Hub U T P  o r S T  P 

• Antenna Hub • Expansion Hub • Supports up to 4 Antenna Hubs • Distributes RF over  UTP/STP Cat 5

• UTP or STP in (RJ45) up to 50 m • Loop powered via UTP or STP • Coax out (SMA)

• Antenna : 3 / 7 dBi

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