4. Why are In-Building Solutions
becoming more important?
• „
Meanwhile 75% of data traffic is
originated indoors
• Landline replacement by mobile
devices
• Wired broadband replacement by
radio technologies
• No network coverage from outside
due to strong RF signal
• attenuation by walls and coated
windows
• Growing capacity demand by
smartphones, tablets, data cards
• Overloading of cell towers
4
5. Indoor Planning Concept
Why need IBS ?
Coverage
– Radio coverage anywhere in
building (no blank spot)
Capacity
– Handle More Traffic In a building
(Using Dedicated site/cell)
Quality
– Excellent Speech Quality
– Always access the network
5
7. Femtocell
• Plug and Play (SON)
• Small, fixed, standalone, low power cell sites.
• a home or small office building
• Maximum number of devices (4 – 20 UEs)
Femtocell Device
7
8. Femtocell Limitations
• Only support a single technology
• A single wireless service provider
• Possible Hand-off to the macro cellular, but
cannot hand-in (under research)
• Need power and backhaul (wired broadband
connection)
8
9. Microcell Solutions
Indoor and Outdoor Coverage
- “microcell” is conventionally used to describe
a single, outdoor, short-range radio transceiver.
9
10. Characteristics of Microcell Solutions
• Support up to 200 users and
has a total range of up to two
miles.
• Require professional
installation and maintenance
• As a standalone device
10
11. Indoor and Outdoor
Metrocell
• A picocell in a high-traffic urban area.
Picocell
• A small cell technology that can be
used both indoors and outdoors
• Indoor : increase capacity in a
defined area
• Outdoors : to fill gaps in coverage
or increase capacity
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12. Picocell/Metrocell Limitations
• Only support a few frequencies
• Only one wireless service provider per
unit
• Costly more than femtocells
– require professional installation and
configuration
• Not interconnected like nodes within a DAS
Network
• A single site may have multiple picocells
deployed to solve a coverage or capacity
issue
12
13. DAS Concept
DAS (Distributed Antenna System)
Base Station/repeater (Component)?
Antenna
Design indoor coverage system :
– Passive distribution
– Active distribution
– Hybrid solution
– Repeaters
13
16. Good Candidates for DAS
• Hospitality
Hotels resorts conference centers Hotels,
resorts, conference centers
• Public Venues
Convention Centers, stadiums, airports
• Government & Education
Govt. offices/municipality, university campuses
• Hospitals
Medium/larger hospitals more than 100 beds
• Mixed Use
Malls, mix of residential, entertainment, and
retail spaces
16
17. DAS Limitations
Outdoors
– Capital investment
– Designing, siting and installing
multiple Nodes
– Miles of fiber optic cabling
– Different from the traditional
macro cellular engineering
process
17
18. Plot Diagram Indoor DAS
Survey Location Plot Antenna DAS
Link Budget
Coverage
Simulation
18
19. Antenna Distribution
• DAS (Distribution Antenna
System) :
– Component :
• Passive :
– Coax cable, Splitter,
Taps/ Uneven Splitters,
Attenuators Connector,
Etc
• Active :
– Master Unit (MU),
Expansion Unit (EU), OF
(Optical Fiber), Remote
Unit, etc
19
20. Passive Distributed Antenna Systems (DAS)
• Essentially a sprinkler
system for cell phone signals
• Distribution via large coaxial
cables
• Losses through the cable
limit the size
• New, higher frequency
bands have high loss
20
25. Active Distributed Antenna Systems (DAS)
• LAN/WLAN-like topology
• Standard structured cabling -
fiber
• optic and CAT5 cabling
• Less disruptive install
• Amplifiers at the antenna point
Amplifiers at the antenna point
means zero “loss”
• Significant cost and
performance advantages in
medium and large buildings
• Excellent performance
regardless of frequency
25
26. Active Component
Master Unit
• Brain of the system
• Generated and controlled internal calibration signals
in the system
• Monitored the performance of the DAS system
Remote Unit
• Convert the signal, back to normal.
• Improve the radio link performance.
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28. Design DAS
• Software design DAS, for examples :
– Microsoft Visio
– Microsoft Excel
– Corel
– Auto Cad, etc
• Design DAS - Wiring diagram
• The purpose wiring diagram - combination the tool
(active and passive component) to distribute power
from base station.
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29. Symbol for Design DAS
• Draw some symbol for designing DAS.
• The symbols can present of equipment , example :
– Antenna
– Splitter
1 : 2 1 : 3 1 : 4
– Feeder
1 ¼” 7/8” ½”
29
30. Loss Equipment
• Loss equipment is total loss components (coax
cable(feeder), splitter, tapper, etc). It can reduce
power from source until antenna.
– For example :
30
32. Recommended Antenna Placement
• Place the antennas and maximize performance.
– Data user (user concentrate)
• Place the “cost-cutting” antennas.
– Maximize coverage per antenna
(corridor effect, material building)
– Give good value for money
• Isolate the Building
– Use directional antennas
(handover zone, outdoor site)
• Fill the gaps
– More antennas in the internal streets
32
33. Indoor Propagation Model
Propagation Model
• Outdoor
– Okumura Hatta,
– SUI, etc
• Indoor
– Cost 231 Multi Wall Model
– Motley-Keenan
– ITU Indoor Model
33
34. Planning Indoor DAS
• Implementation Steps
• DAS Installation
• Wiring Diagram
• Link Budget Calculation
34
35. Implementation Steps
Budgetary design – usually based on floor
plans
– Determine which areas of the building require
coverage (entire building, public areas, parking
levels, etc.) Coverage need analysis
– Determine the building’s construction materials
(sheetrock, metal, concrete, etc.)
– Determine capacity requirement.
– Determine budgeting
35
36. Coverage Needs Analysis
• Two main factors that demonstrate signal
– RSSI–Received Signal Strength Indicator
• Measured in dBm
• -85 dBm is the typical threshold
• Lower dBm ( e.g. -95 dBm) = lower signal
– Quality
• Typically a Signal to Noise based ratio – Ec/Io,
SQE, C/I
• Thresholds vary per service provider
• Noisy room example (high rise)
36
Drive Test Tools
41. Wiring Diagram
• Why Wiring diagram ?
– Total power & loss component in the real
condition in building.
– Including : location, distance, power
• Wiring Diagram With DAS
– Base Station with multiple antenna
• Calculate link budget :
– Manual
– Software (Ms. excel, Matlab, etc)
41
43. Design: Keys to Link Budget
• Power output at repeater or fiber remote
# of channels per service provider
• Splitter and cable loss
• Free Space Path Loss
# of wall penetrations
• Fade Margin
• Use link budget as guide for RF design
43
44. Power Link Budget
Calculate loss total in building :
Loss = ∑Lfeeder + ∑Lsplitter + Ltapper
+∑Ljumper + ∑Lconnector
EIRP = Pin – Lline + Gain Antenna
EIRP = Effective Isotropic Radiated Power
44
47. Exercise : Wiring Diagram and Link Budget
Calculation
• Open Microsoft Visio
– Draw wiring diagram in this Building
• Number of Floor 4 floors, each floor has :
– Size : 30 meter x 12 meter
– 12 rooms (size 5m x 5 m)
– 1 Corridor (2 x 30 meter)
• Estimate antenna and placement
• Draw wiring diagram
• Open Microsoft Excel
– Link Calculation
47
48. 1. Open Radio Propagation Software (RPS)
2. Radio Parameter Setting
3. Import Map Data
4. Draw Material Layer
5. Configure Transmitter and Receiver
6. Propagation Setting
7. Generate Simulation
8. Simulation Output
9. Show Simulation Result
Indoor Simulation using RPS
- Step by Step-
48
49. Indoor Simulation
Step by Step:
1. Open software RPS(Radio Propagation Simulator)
5.4 students version
– [start]->program->RPS 5.4
This software support map from :
– AutoCAD and CorelDRAW (*.dwg, *.dsf ,*.vdf)
RPS 5.4 students version can simulations receive signal
level (RSSI) by user (dBm)
49
53. Create Map
Draw map from AutoCAD or
CorelDRAW and save to this format
: (*.dwg, or *.dsf , or *.vdf)
• Map size must be same with the
real condition (meter)
• Open Corel Draw or AutoCAD.
– Draw Example Building
• Size : 50 meter x 12 meter
• 10 rooms, 1 Corridor, Material :
Concrete
AutoCAD
53
54. Indoor Simulation
3. Import map data :
[ File -> import -> Import DXF or DWG
Environment Data Files ]
Format : *. dwg, *.dxf, *.vdf
Example Map :
*. dwg
54
55. Example : 2D Map Building
Example 2D
Building Map
View 2D/3D
55
56. Material Layer Setting
4. Draw Material Layer:
[ input height wall , materials
data, and layers ]
Create 3D Wall
Material Database
56
58. Place Antenna and Receiver
5. Configure Transmitter and
Receiver :
[ input antenna, transceiver,
and receivers ]
Antenna type
Carrier
Frequency
Transmit
Power/EIRP
Antenna
Name
Double Click
58
63. Simulation Result
• Surface Plot
– Coverage /Power Receive on floor (Receive Signal Level)
– Delay Spread
– Signal to Interference Ratio
– Best Server
Coverage
63
64. Simulation Result
Average Signal Receive/Coverage
Receive Signal
Level(dBm)
Cumulative
Distribution Function
(CDF)
Probability
Distribution Function
(PDF)
Mean/Average
64
