ITU Kaleidoscope 2011
The fully networked human?
Innovations for future networks and services
Transmission Analysis of Digital TV
Signals over a Radio-on-FSO Channel
Chedlia Ben Naila1, Kazuhiko Wakamori1, Mitsuji Matsumoto1
and Katsutoshi Tsukamoto2
¹GITS, Waseda University, Japan
²Graduate School of Engineering, Osaka University, Japan
chedlia.bennaila@toki.waseda.jp
Cape Town, South Africa
12–14 December 2011
Outline

Introduction

Overview of Radio over FSO Technology

Experimental Evaluation of ISDB-T based
Wireless Services Transmission over RoFSO
Channel

Conclusion
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
Outline

Introduction

Overview of Radio over FSO Technologies

Experimental Evaluation of ISDB-T based
Wireless Services Transmission over RoFSO
Channel

Conclusion
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
4
Introduction
The need to communicate, exchange and
share information prompted the deployment
of devices and applications such as:

These applications and the emerging ones
all have one “common effect” on the end
users/businesses…
MOBILE PHONES, HOME PHONES, BROADBAND,

…increased Bandwidth requirement!
OFFICE PHONES, DIGITAL TV, VIDEO CONFERENCING,
TELEMEDICINE, TELE-TEACHING AND MANY OTHERS
ARE EMERGING BY THE DAY
How can users have access to the required high
bandwidth? Optical fiber
Deployment of optical fiber in the backbone and
metro networks have made huge bandwidth available to
within one mile of businesses/homes in most places.

But… time consuming, digging, need for permission…
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
Overview of RoFSO systems

5
Free Space Optics (FSO)…
refers to the transmission of visible and infrared (IR) beams through the atmosphere
to obtain optical communications.

Radio over FSO (RoFSO)… RoFSO = FSO + RoF
Next Generation FSO system=Direct coupling between optical fiber and free-space
Free-space beam directly
coupled to optical fiber
RoFSO
antenna
RoF
DWDM RoFSO
Heterogeneous wireless
channel
service signals
RoF
Proposed DWDM RoFSO system
 Uses 1550nm wavelength
 Transport multiple RF signals using
DWDM FSO channels
 Realize heterogeneous wireless
services e.g. WLAN, Cellular,
terrestrial digital TV broadcasting etc
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
Free Space Optics Standards Start!
In March 2006, the first ITU-T Recommendation
has been published:
Entitled
“Co-location
longitudinally
compatible
interfaces for free space optical systems”, ITU-T
Recommendation G.640 (ex G.fso) means that users
of FSO systems will be able to co-locate FSO solutions
provided by different manufacturers for the first time.

Calculations of the conditions required to be met to
prevent interference in some examples of co-located
FSO systems are also included.

Need for a ITU-T standardization study for maturity
and rapid adaptation of the newly developed RoFSO
technology.
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
6
Outline

Introduction

Overview of Radio over FSO Technologies

Experimental Evaluation of ISDB-T based
Wireless Services Transmission over RoFSO
Channel

Conclusion
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
8
Experimental Setup of RoFSO System
Forward / Backward
beam on single axis
Rough tracking sensor
with 850 nm beacon
2-axis
gimbal
Direct coupling between
Space and SMF
Signal light
SMF
Beacon (850 nm)
Collimator & Fine
Pointing Mirror
QD
Vx
PID：proportionalintegral-derivative
Vy
PID
controller
Fine tracking
sensor with QD
x
Error evaluation
electronics
y
Q1 Q2
Q3 Q4
RoFSO antenna optical
path and device layout
P1 P2 P3 P4
DWDM RoFSO antenna specifications
Parameter
Communication wavelength
Value
1550 nm
Beacon wavelength
850 nm
Antenna aperture
80 mm
Beam divergence
Optical transmit power
Coupling losses
47.3μrad
20 dBm
5 dB
Key features:

Optimized
signals.
for
transmission

Can suppress most of effects induced
from atmospheric turbulence like
beam wander, AOA fluctuations.
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
of
RF
9
Schematic Diagram of RoFSO system
1 km
RoFSO
antenna
FSO link
RoFSO
antenna
Output
monitor
3dB
coupler
Power
meter
SM-Fiber
Atmospheric turbulence, rain, fog,…
Optical
IF-unit
Opt. Spectrum
Analyzer
EDFA
EDFA
Optical
IF-unit
2.5 Gbps
2.5 Gbps
Opt. Rx
Opt. Rx
RF-IF-unit
RF-IF-unit
BERT
BERT
Data
logging PC
ISDB-T
Signal analyzer
Site2: Bldg. 55S Okubo Campus
ISDB-T
Signal generator
Data
logging PC
Site1: Bldg. 14 Nishi Waseda Campus
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
ISDB-T Signal Transmission:
Introduction
Integrated Service Digital
Broadcasting - Terrestrial (ISDB-T)
is one of international standard
for terrestrial DTV broadcasting
format developed and adopted in
Japan and in almost all the South
American countries.

Layer A
(LDTV, Audio,
Data)
10
13 segments
(6 MHz bandwidth)
Layer B
(HDTV or 3 SDTV
with data)
frequency
Handheld reception
(1seg service)
Fixed and mobile
reception (HDTV, etc)
ISDB-T channel segments and services
The bandwidth is divided into 50
channels numbered from 13 to 62.
 Each channel is further divided into 13
OFDM segments which includes a single
segment, (Layer_A or 1seg) for mobile
receivers (LDTV, audio and data) and the
remainder can be allocated as one 12Countries and territories using ISDB-T segments (Layer_B) for high definition
television (HDTV) programs.
in green (Wikipedia)

Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
ISDB-T Signal Transmission
Characteristics
ISDB-T Transmission parameters
Parameter
Value
Mode
3
Layer
A
B
Number of segments
1
12
Modulation scheme
16 QAM
64 QAM
Information bit rate
624.13
19660
Required CNR/MER
(dB)
11.5
22.2
Ch 13
Ch 14
Movie
Clip
Test
pattern
11
6 MHz
offset
Received ISDB-T signal spectrum
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
ISDB-T Signal Transmission:
MER Evaluation (1/2)
12
Modulation Error Rate (MER) Definition:
Ideal Symbol
Q
RMS Error
Magnitude
Q
(Ij,Qj)
(Ij,Qj)
I
dQj
dIj
I
Average Symbol
Magnitude
1seg (MER= 23dB), 12seg (MER= 23dB),
1seg (MER= 35dB),
12seg (MER= 35dB)
ISDB-T Modulation analysis and
Received Optical Power Characteristics
ISDB-T Constellation Map
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
ISDB-T Signal Transmission:
MER Evaluation (2/2)
Variation of the MER versus
the received optical power
Variation of Average and
Variance of ISDB-T MER with the
2
refractive index Cn
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
13
ISDB-T Signal Transmission:
BER Evaluation
Error Correction limit 2  10
14
4
2  10 4
Error Free
ISDB-T BER and Rx. optical power
characteristics
The CDF Layer A and Layer B BER
Test Signal : ISDB-T_16QAM_1_2 (Layer A 1seg 16QAM, Layer B 12seg 64QAM)
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
Outline

Introduction

Overview of Radio over FSO Technologies

Experimental Evaluation of ISDB-T based
Wireless Services Transmission over RoFSO
Channel

Conclusion
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
Conclusion
16

An experimental evaluation on transmission of ISDB-T
service signals using a newly developed advanced
DWDM RoFSO system under real operational environment
has been presented.

Transmission performance evaluation of the proposed
RoFSO
system
has
demonstrated
consistent
performance in terms of specified quality metric
parameters for the OFDM based digital TV signals in the
absence of severe weather conditions and using
properly design interface units.

The obtained results confirm the technical feasibility and
practicality of utilizing the RoFSO system as a universal
platform for providing ubiquitous wireless services.

The presented work on the newly developed RoFSO
system can offer guidelines for an ITU-T standardization
study for rapid adaptation of such technology.
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services
This work was supported by a grant from the National Institute of
Information and Communications Technology (NICT) of Japan.
Thank you for your attention!
Chedlia Ben Naila


Waseda University, Tokyo, Japan
chedlia.bennaila@toki.waseda.jp
Cape Town, South Africa, 12-14 December 2011
ITU Kaleidoscope 2011 – The fully networked human? Innovations for future networks and services