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A wonder called RADIO
“No wonder so many physicists started as radio tinkers,
and no wonder,
before physicist became a commonplace word,
so many grew up thinking they might become electrical engineers”
-Gleick in the biography on Richard Feynmann
We will stick to the definition of Radio as• Wireless Audio Delivery
•Listener cannot by himself choose the contents
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History of Radio Technology
1888: Hertz produces EM waves
1895: Marconi transmits EM Waves
1897: Ship-to-Shore Wireless Communication
1903: First transatlantic message
1922: First Broadcast Station
1950: First FM Broadcast
1999: First Satellite Radio Broadcast
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Science of Radio
“One ought to be ashamed
to make use of the wonders
of science embodied in a radio set,
while appreciating them
as little as a cow appreciates
the botanic marvels in the
plants she munches.”
- Albert Einstein (Aug 1930)
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Satellite Orbits decided by Applications
Types: LEO,GEO,HEO….. In a geostationary orbit the satellite is in the same direction in the sky all the time Such orbits ideal for Broadcasting Picks up signals from a fixed station and relays instantaneously to huge areas
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Geo-stationary OrbitGeo-stationary Orbit
GEO an Equatorial Orbit, hence no
coverage for polar regions
Application Categories:
FSS, MSS, BSS, DAB…
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Link Design Considerations
A*B/C > Threshold, Where A is the satellite transmit characteristics, determined by state-of art satellite power, coverage area;
B is Receive characteristics, determined by size and cost of thereceive system;
C is propagation characteristics.
Majority GEO satellites (C & Ku) choose B values corresponding to DTH (1 foot antennas) or higher
DAB satellites address Direct-to-Person and hence have B values 100 times lower. Hence, link margin requires A to be 100 times more.
Also, DAB satellites incorporate several digital processing techniques
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DAB Satellites Spectrum
L-bandS-band
Audio Compression MPEG AAC+
RF Design Propagation Models TDM, MCM, OFDM
Examples WorldSpace XM Sirius MBSAT
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Satellite Radio: A Confluence of Technologies
RadioRadio
Internet
Internet
Satellite
Satellite
Digita
lDigi
tal
Live DeliveryLive Delivery
Multiple User Multiple User TerminalsTerminals
AudioAudioVideoVideo
Digital Digital LibraryLibrary
Targets Select Targets Select AudiencesAudiences
ScalableScalableVirtual Virtual ClassroomClassroom
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Basic System Architecture
Broadcasters• Common Hub• Individual VSAT-like
Ground Control Facilities• Telemetry, Command,
and Ranging Stations• Mission Control
Geo-Stationary High-powered Satellites• Processed and Transparent
Payloads• Solar-Powered
Provides a complete end-to-end network
New Digital Portable Receivers• Direct Reception
through Small Detachable Antenna
• Digital Quality• Proprietary Chipset
with MPEG-2, Layer 3Encoding
• Multimedia Capability
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LOS to Satellite
Repeater Coverage Region1
2
3
elv
Terrestrial MCM Single Frequency Network
Radiated MCM Signals Synchronized Relative To Center of Coverage
CoverageCenter
All SFN Stations Are Equipped With A TDM/MCM Transcoder
elv
elv
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Growth of Satellite Radio in the US
In the US there are two systems providing DAB: XM and Sirius
Both use S-band and both have terrestrial augmentation
XM has 3 GEO satellites; Sirius uses 3 HEO (Tundra orbit) satellites
XM started Sep 2001 and has >5 million subscribers
Sirius started July 2002 and has > 2 million subscribers
Both provide >100 radio channels, unique formats, commercial-free, local traffic information etc
OEM partnerships with automobile industry
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Revival of the Radio
For those on the Move (land/sea/air) For those occupied otherwise For the illiterate For kids For Teaching ……
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Uplink Station
Live/Recorded
Audio: How it can be usedAudio Uplink to Satellite
Satellite
Individual
Transmission to Audio Receivers
Village Classroom
Content :– Locally & regionally relevant– Culturally appropriate– Practical & solution-oriented– Balanced & accurate/non-political
Emergency Preparedness
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Teaching with Audio
More human and personal than Print or web
Extempore Delivery and the novelty that goes with it
Intonation,Phrasing & Pacing that are not easily brought out in print or on the web
The Synchronous Data Channel adds a new Dimension to the delivery
Integration with existing systems:
•Pilot Experiment in west coast of India, 2000-01
•80 boats fitted with WorldSpace reception
- Encased in water proof enclosure- Powered from the boat- Additional 8W amplifier - Pretuned to the assigned channel
•Warning messages in MP3 format via Internet to the uplink site
•Boats into the sea up to 200 miles
•Valuable experience gained in designing the full system
Cyclone Warning System for Fisherman out at Sea
•Pilot Experiment in west coast of India, 2000-01
•80 boats fitted with WorldSpace reception
- Encased in water proof enclosure- Powered from the boat- Additional 8W amplifier - Pretuned to the assigned channel
•Warning messages in MP3 format via Internet to the uplink site
•Boats into the sea up to 200 miles
•Valuable experience gained in designing the full system
WorldSpace Reception on a Fishing Boat
•Pilot Experiment in west coast of India, 2000-01
•80 boats fitted with WorldSpace reception
- Encased in water proof enclosure- Powered from the boat- Additional 8W amplifier - Pretuned to the assigned channel
•Warning messages in MP3 format via Internet to the uplink site
•Boats into the sea up to 200 miles
•Valuable experience gained in designing the full system
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Audio Broadcasting for Emergency Relief
India Reconstruction and Relief
Indonesia Disaster Relief
Equal Access Afghanistan & NepalDistance Learning and Radio Dramas
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InformationCommunications
Technologies
From Immediate Disaster Relief to Long-term
Development
Power of Information & Communication Technologies
“With most information technology innovations,
we have constantly overestimated the speed with which they will unfold
and underestimated their eventual impact.”
-Bill Gates
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Information Vs. Communication Divide
Bridging the Information Divide (One to Many, public)
Commonality of Information requirements Content has to be based on local needs Need for low cost connectivity solutions Bridging the Communication Divide (One to One, private)
Needs local-loop connectivity (Fiber, cable, WLL…) Economics strongly varies from place to place
Two-way communication not a precondition for narrowing the digital divide Selective and secure Information delivery is a major catalyst for development
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••InternetInternet--type downloads type downloads withoutwithout an Internet connectionan Internet connection
Multimedia: How it can be used
Receiver + MMS Adaptor + computer
Multimedia adapter converts receiver to modem for download of data from satellite to computer
Uplink Station
Internet
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Cache
Proxy Server
Collection of
relatively stable
web pages on DVD
Using Data Broadcast by Satellite to transfer web pages
Local Area Network
Dial-up Equipment
Telephone Network
Using satellite radio
One can do away with the last-mile problem
And scale the solution
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What is ...???
Teacher
CLASS: Combined Live Audio & Slide Show
Questions via Internet, phone, pager Classroom
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Several Applications….
Virtual Classroom(all levels) “Best” teacher to reach all Teacher Training (pre or in service) Supplementary school material Professional Needs (e.g. health workers) Radio for Infotainment Community Information Kiosk
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Digital Data Signage
POS advertising, Product/brand promotions Retail industry
“While-you-wait” messaging Hospitality industry
Lounges in bars, restaurants, casinos, hotels and resorts Personal service industry
Waiting areas in banking, laundry, grooming and health care (doctors, dentists, hospitals)
Public spacesAirports, bus/train stations, malls, movie theaters, museums and convention centers, pedestrian and highway billboardsEsoteric - Elevators and buses, trucks, and taxis
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Mobile Broadcast: Satellite Weather Information System
WorldSpace Satellite
Real-time
graphic
display in
cockpit
Incoming data files from Jeppesen
SWIS Server
PFLS
64 kbps
Internet
Applications Overview
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Health Information Delivery Doctors - Better service, easier/convenient access to latest information Institutes - Better service, training for medical staff, easier access to latest information Students - Data on specific topics, easier access Pharmaceuticals - delivery of information including pricing and new product updates
Cost effective, efficient way accessing focused medical and health information
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Also on the service:•Emergency Meteorological Information•Governance•Health•Teacher training resources•Agriculture
Multimedia Delivery
First Voice Multi-Media Service in Africa and Asia
Community workers in 34 centers in rural Eastern Africa receiving NRM data
Meteorologists and rural extension workers in Africa and Asia/Pacific Island Nations receive hourly updates of climate information
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RANET Initiative: Radio and Internet for the Communication of Hydro-Meteorological and Related Information
Critical and timely information on:
Disaster Relief Meteorology Via Multi-Media Service to many nations across Africa and Asia/the Pacific
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Coexistence of different Radio Systems
AM/FM: Primary Formats; Inexpensive radios
Satellite Channels: Specialized Formats; Diversity in sparsely-populated areas; Possible multi-media delivery where Internet is poor
Internet Channels: Allows to engage more deeply and more directly
Podcasting: Allows special contents shared among closed user groups
Even though satellite radio was designed to meet the needs of the affluent mobile customer of uninterrupted, high-quality reception of a variety of formats, the design allows to adapt the same for community needs and one-way delivery of digital contents to multiple destinations selectively, securely and reliably.