Das solution

giải pháp DAS mimo trong hệ thống viễn thông Giải pháp SC MIMO bao gồm hai thành phần chính: Head Unit (HU) và Service Unit (SU). Các thành phần cần thiết khác là Bộ lọc DC+IF và Bộ ghép DC Pass.

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Overview of DAS Solutions

15-Jul-2017

▪ In-Building Design Trends

▪ Marketplace Solutions and Building Types

▪ Approaches to In Building System Design

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In-Building Design Trends

▪ Network Operators Prefer Passive Solutions

▪ Radiating cable now widely used

▪ Fibre optic technology used only where necessary

▪ Solution for large buildings

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Passive and Active DAS

Passive Solutions

Active Solutions

Expansion Hub

RAU

RAU

RAU

CAT-5 or Hybrid Fiber

Main Hub

Cable

Donor BTS

Distributed Antennas

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Why Use Distributed Antenna?

▪ Applicable where narrow range of frequencies are required and future expansion into other bands is not anticipated

▪ Single or Dual band systems

▪ To provide hot spot coverage of open areas

▪ Highly cost effective

Why Use Radiating Cable?

▪ Flexibility / Cost- Effective Upgrading

▪ Broadband capability

2700MHz

▪ Advantages of leaky cable

▪ Less close / far signal difference.

▪ Disadvantages of leaky cable

▪ Difficult to match with interior design.

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Radiating Cable vs Antenna

▪ Major issue is the topology of the

required coverage area

rectangular or circular disposition.

and narrow office spaces such as those

wrapping around the core of a high rise

▪ Containment of signal within defined

coverage area more easily achieved

with radiating cable

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▪ A radiating cable solution is generally more costly (material wise) than an antenna solution

▪ Flexibility / Cost

unlimited number of services ranging from 1MHz to 2500MHz.

later without further installation costs.

would require a new antenna system

Antennas vs Radiating Cable

-110

-50 -40

-60 -70 -80 -90 -100

Antenna Coverage

Radiating Cable Coverage

Signal Strength

Distance

▪ Capable of handling multiple downlink

carriers with no measurable IM

products

▪ Inherent insertion loss limits the size of

installation to typically a 35 floor high

▪ Duplex cellphone systems require elaborate and relatively expensive linear BDAs

▪ Linearity is critical; multiple carriers escalate 3OIP and power rating of downlink PAs

▪ Multiple radio platforms necessitate band-dedicated BDAs

Passive DAS for LTE-A?

Pros of Passive DAS

▪ An all-passive coaxial cable system is highly linear

▪ Capable of handling multiple downlink carriers with no measurable IM products

▪ High system reliability

Cons of Passive DAS

▪ Feeder cable size is typically limited to 7/8” or 1-5/8”

▪ Not suitable for buildings that require long feeder runs

▪ At high frequencies, the system loss becomes very high

▪ Lower DL coverage, poorer uplink sensitivity and reduced SNIR

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Hybrid DAS

▪ Most cost effective solution

▪ Difficult to manage uplink active system

from interfering with passive DAS

Hybrid Solutions

Master Unit

Coaxial Cable to Antennas

Coaxial Cable

Unit

Remote Unit

Hybrid DAS Application Scenarios

1 Multi Story Skyscraper

Coax

Ant

Rad Cable Fiber

40 th

Floor

Ant Coax

Rad Cable

3 Campus Environment

Fiber Optics Remote Unit

Fiber Optics Remote Unit

Fiber Optics Master Unit

2 Shopping Center

BTS

Ant Coax

Rad Cable

Attached High Rise Building

Master Unit Fiber Optics

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Optimum Amplifier Placement

▪ Best results when amplifier is placed near to antenna

▪ UL NF is minimized, i.e better sensitivity

▪ Trade-off between how close amplifier is placed to the antenna, and number of

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Optimum Amplifier Placement

▪ Scenario 1: No Amplifier

BTS NF plus cable loss

▪ Scenario 2: Amplifier Near the Antenna

between BTS and amplifier.

System Noise Figure = 50 dB

System Noise Figure = 16.2 dB

RX

NF = 10dB Gain = 40dB

Overall NF 16.19 dB

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Optimum Amplifier Placement

▪ Scenario 3: Amplifier Far from Antenna

▪ Amplifier gain compensates for feeder loss and thereby increasing performance

System Noise Figure = 50 dB

RX

NF = 10dB Gain = 40dB

Stage 1 Stage 2 Stage 3 Stage 4

Overall Gain -5 dB Overall NF 50 dB

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NF h

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Approaches to Implement

Coverage Solutions

Coverage Solutions

Capacity

RF Repeater, Pico Repeater + DAS

E.g., Small Restaurant and Building

RF Repeater, Booster + DAS

E.g., Supermarket, Residential Building

BTS + DAS

E.g., Office Building, Shopping Mall

BTS + Fiber Repeater / Booster + DAS

E.g., Airport, Megamall

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High Capacity + Small Coverage Applications

POI

H C

Triplexer

WCDMA BTS DCS BTS

D C

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High Capacity + Large Coverage Applications

▪ Fiber optic repeaters are often used for large scale in-buildings where high

coverage and capacity are needed

▪ Typical applications are in airports, underground metros, exhibition halls, campus buildings, etc

Donor Antenna

Low Capacity + Large Coverage Applications

Optical Repeaters

OAR HC

BTS

Master Unit

Remote Unit

Remote Unit

ANT Optical Fiber

Pico Repeater BTS

▪ Using Indoor Pico Repeater

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Summary

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Smmary

▪ The new Rosenberger Smart DAS solution can provide a flexible solution for a high power hybrid DAS and low power active DAS

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THANK YOU

www.rosenbergerap.com