From: pbaatech@peg.apc.org
Subject: The Complete DAB, Part 1 of 6
Originator: wdp@gagme
Organization: Austraila Public Radio
Date: Thu, 15 Oct 1992 00:00:06 GMT


****************************SECTION ONE**************************
*******INITIAL IMPRESSIONS FROM THE MONTREUX DAB SYMPOSIUM*******
**********************HELD 8 AND 9 JUNE 1992*********************

The stated aim of the Montreux DAB Symposium was clearly to 
present a strategy  for the introduction of DAB worldwide by the 
EBU (in collaboration with the partners of the EUREKA 147 
project)

Some 528 participants attended the symposium, of these only 59 
came from geographical area outside the direct sphere of 
influence of  the European partners:

USA: 			25
Japan: 		12
Canada: 		5
South Africa: 	5
Australia: 	3
Mexico: 		3
Korea: 		2
Brazil: 		2
China: 		1
New Zealand: 	1

>From the onset, it becomes apparent that the whole affair was 
very much a European concept, developed by the EUREKA 147 project 
in association with the European Broadcasting Union (EBU).It is
interesting to note that The project Manager, Mr. Meier-Engelen  
has indicated clearly that the EUREKA project was not part of the 
EBU; this was also confirmed by the Secretary of the EBU in 
private conversations in Geneva.

It seems now that the relation between the EBU and EUREKA 147 
is somewhat akin of the relation between a client (EBU) and a 
supplier (EUREKA 147). And while the Symposium was conducted on 
sound engineering lines, the fact that a number of addresses 
could be seen as very articulate "sales pitch" was not lost on a 
number of delegates.

Considering the fact that the system, developed by the European
partners is proposed as a world standard, it is useful to 
consider who are the players, and thus where the powers lay.

The EBU is representing essentially European Broadcasting
Organisations   As an illustration, earlier this year, the EBU 
has sent a questionnaire to its members in order to investigate 
the variety of opinions and interests with respect to the 
introduction of DAB, concentrating primarily on system design, 
receiver implementation, and terrestrial service delivery.
It is reasonable to assume that the answers to this questionnaire 
will be used in some way in order to tie-up the specifications of 
the proposed DAB system.

The questionnaire was sent to 35 organisations, all members of 
the EBU, only three being outside Europe.. The answers to this 
questionnaire are a good guide as to what is being considered for 
Europe (and the world at large, if the system is being accepted 
overseas); already, a number of Administrations have aligned 
themselves with the EBU, with view of implementing the EUREKA 147 
system in their respective parts of the world, Australia, Canada 
and Mexico being three of the likely candidates.

It should be noted that the questionnaire sent by the EBU has 
been confined to EBU members exclusively, while the development,
specification and implementation of DAB may have worldwide
consequences if the EUREKA 147 system can be in effect"sold" to 
the rest of the world. Thus the Australian Broadcasting 
Corporation  has replied to the questionnaire, in its own right, 
as an EBU Member. 

This document has not, to my knowledge, been passed on to the 
Australian DAB platform (DAB Committee) for comments, and thus 
may not  represent the view of the Australian broadcasting sector 
as a whole.

The point here, generally, is that, whatever input has been 
brought to bear over the designer of the system, it has been 
confined to  "large" organisations only, and also a certain type 
of organisations, all havingthey own aspirations and motivations. 

The fact that the "Public" broadcasters in Europe aspire to a 
certain supremacy over their "private" colleagues is no secrets. 
As for community radio, they  do not rate much in the scheme of 
things as far as I can ascertain, this  being confirmed by 
delegate of the Federation.Europeene des.Radio.Libres ( FERL). at 
Montreux.

EUREKA 147 PROJECT is made up of a number of exclusively European
organisations, in total 20 partners in all, and likely to grow. 
Of this number, 11 are actively engaged in  the manufacture of 
electronic equipments, mostly in Germany. The brake-up of 

The consortium is structured as follow:

Germany : 		11 , 	(9 manufacturers)
France: 		4 , 	(2 manufacturers)
United Kingdom: 	1, 	(BBC)
Netherland: 	1, 	(Philips)
CIS : 		1, 	(Popov Institut)
Italy: 		1, 	(Radiotelevisione Italiana)
Sweden: 		1, 	(Swedish Telecom)

There is a market out there, million of receivers to replace 
eventually, not to mention transmitting equipment.
The manufacturers are well placed within the project, and 
possibly  a driving force. 

It is perhaps also significant that from the  original 12 members 
of the EUREKA 147 Project, five out of the 9 new members are 
large manufacturing companies, Thompson LER, Thompson LGT, Rohde 
& Swartz, Daimler Benz,Becker GMBH, one having dropped-off(AEG).

Admittedly, other parties have an influence in the shaping of 
DAB. The CCIR is actively engaged in study of the system, and in 
fact, it is still (in principle) possible to see emerging another 
system competing with EUREKA 147; This would be System B, as 
opposed to System A  proposed at Montreux.

Japan may yet come with a viable proposition, and the US is 
claiming rapid progress in the so-called IN-BAND system, designed 
to operate in the present FM band in addition to existing 
services,  and likely to be demonstrated sometime later this 
year, probably at the NAB show in New Orleans.

But at this stage, and if the European have their ways, The world 
may be "obliged" to adopt EUREKA 147 by default, in one form or 
another; the development is well advanced and any of the 
demonstrations made so far tend to convince even the more 
reluctant observer.

A demonstration of the system was made at Montreux. It consisted 
of a simultaneous broadcast over a DAB channel and over an FM 
channel.  The transmitters had been located across the lake, 
beaming toward Montreux. A large "Mercedes Bus" (with factory 
driver) was available for a demonstration tour of some 30 
minutes, ranging from town condition to express-way condition, 
including a tunnel, just under 1 km.in length. 

To this effect, a gap-filler had been installed at the 
entrance of the tunnel, another gap-filler was also provided in 
one "shadowy" area at the end of the lake. Monitoring was 
available via good  quality headphones, and a number of spectrum 
analyser, provided a display of the FM carrier and of the DAB 
bloc. A switch was provided for either FM or DAB listening.

The result of DAB over FM is spectacular !  While the FM suffers 
from interference, drop-out and pickets effect, the DAB is rock 
solid, and in fact was not lost or affected during the whole 
trip. Real CD quality in a vehicle.

So its works, and even works VERY well.

BUT, there are some questions that need answers, and in the 
present climate, (high motivation, secrecy dictated by commercial 
interests and so on ), answers are hard to get. While the 
literature given  to us is rather impressive, and seemingly 
comprehensive, a number of topics are (perhaps conveniently) left 
out. Unfortunately, these topics  are of vital concern  to 
community broadcasters the world over, and hot potatoes for the 
EBU/EUREKA partners.

THE FIRST QUESTION, (and probably one of the most important
aspect of the new technology) is the ability to provide "small" 
coverage", applicable to a small suburban station within a 
larger network designed around the EUREKA 147 planning options. 

This aspect of network planning has not really been addressed by 
the system designers of the EUREKA 147 project. The system was 
initially designed for satellite based services, and has 
subsequently been adapted to terrestrial coverage,  when it was 
evident that spectum for satellite  services would not be 
available until sometime in the next century. 

I understand that the designer of the EUREKA 147  project are now
aware of this issue; whether they come with some acceptable 
solution remainsto be seen.

As an illustration, lets consider how a small community station, 
e.g. 2RES in Sydney, providing a 150 watts ERP service to a 
suburb called Paddington  would enter the DAB field

There is no satisfactory solutions to this aspect of network 
planning yet, or at least no economical means of providing small 
coverage, seemingly short of implementing a full 1.5 MHz block 
capable of carrying some 6 stereo channels and some datas 
channels,  or a lesser amount of audio channels and some 
additional data material. This sound very nice, until the cost 
element is brought in:

(i) The cost of establishing a single DAB transmitter is not 
known, but it is likely to be more than just a small 100 W ERP 
VHF/FM unit fed by landlines or a STL.

(ii)In theory, a small station could offset the cost of DAB 
equipment by lease of the unused portion of the available program 
capacity; this is debatable. To find another 5 broadcast services 
interested in Paddington area for example may prove difficult. 
The same may apply to data distribution, most services supporting 
data may wish a larger coverage area, and thus they may choose to 
utilise the larger city-wide network run by more conventional 
services..

(iii) There is also the matter of spectrum usage, and cost of 
spectrum. To implement small-area coverage for DAB in a city the 
size of Sydney would require at least 4 different frequency 
blocks of 1.5 MHz.while in theory, all other broadcasters may use 
only one block to achieve they required wide coverage of the same 
city, if Single Frequency Network (SFN) is implemented; Note that 
the concept of SFN  implies also that the frequency of operation 
may have to be below 250 MHz according to the  information 
obtained in the Symposium.

I have discussed this problem with a number of key people in the
EUREKA project, and canvassed the various options ranging from
staying on FM to implementing local DAB networks.

While some technical avenues are yet to be explored, the initial
reaction is that it is a fact of life, and that small community
broadcasters will have to be made aware of the problem in order 
to plan their services accordingly, e.g. extending their coverage 
area, or sharing a wide coverag channel  

Generally, the option of staying  on FM, while initially offered 
as a solution, is not pursued very far; it is clear that in 
Europe at least, DAB has its eye on the FM Band. In Australia,
it seems evident that resumption of the FM Band is considered;
this part of the spectrum is deemed valuable (dollars and cents) 
and would be grabbed by the communication industry if they had a 
chance.

Finally, this issue of small coverage and network planning raises
important issues for community broadcasters in the third world.It 
may come to pass that here, in Australia, we will find a 
compromise in order to accommodate the small stations in a DAB 
climate with the assistance and cooperation of the Australian 
Broadcasting Authorities. This may not be the case for a number 
of other countries around the world.

THE SECOND QUESTION is a matter of cost again, but for all 
community broadcasters wishing to operate a DAB system. Stringent 
processing and synchronisation requirement will apply to signal 
delivery to the main multiplex unit, resulting in considerable
delivery costs.

Also, while it seems that the cost of establishment of DAB 
network based on SFN is about half of conventional VHF/FM 
network, the example given in an attached paper do not reflect 
the cost of DAB service based on conventional planning techniques 
(Local). In fact, there is very little documentation on the so-
called local network planning, and quiet a few reservation 
expressed in what is submitted. 

Basically, the DAB savings in term of cost and spectrum rely 
principallyon SFN implementation, aided by satellites 
distribution of program feed to individual transmitters.

THE THIRD QUESTION is, what may be the implication of the wide 
range of data services possible within the multiplex and how much 
will this feature compete for access with community broadcasters. 

This subject is raised a number of time by various speakers at 
the Symposium and will need careful  evaluation.

These are my initial impressions   The development of DAB is
progressing very fast, and it will be interesting to see what 
develop not only from Montreux, but also from the IN-BAND 
proposals in the US over the next few weeks/months.


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