Satellite Radio: Its Global Impact

TIFR Alumni LectureBy

S.Rangarajan

1

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

2

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)

4

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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WorldSpace Coverage

In Service

In Service

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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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Technology to aid Education

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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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Data ServicesHow the availability of the DAB system can be flexibly exploited

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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.