QMW

Distributed Systems Group: Djinn Project
Digital Studio Questionnaire

Introduction

Djinn is a framework consisting of a programming environment and system architecture for distributed multimedia applications. We focus on groupware applications in particular, for which multimedia data, especially audio and video communication, are normally considered essential. These applications provide significant challenges in the areas of program design and distributed system support. This is due to their complex construction and because their demands on system resources vary at run-time. Users join and leave applications while they run, and the system load imposed by the applications also varies in response to user actions. For example, students may join and leave an electronic forum for studying by distance-learning, which involves changes in the audio and video communication structure. The requirement to accommodate the dynamic reconfigurability of the media streams in these applications demands an investigation into the modularity, reconfigurability and re-usability of their construction, and into the system for admission control and application instantiation and management that underlies them.

As a basis for evaluating the usefulness of the concepts in Djinn, we are attempting to develop detailed requirements specifications for "real world" multimedia applications. In particular we are looking for applications with tight constraints on service guarantees and potential for reconfiguration at runtime. One such application area is the all-digital television studio or video production/post-production facility.

More information on the Djinn project can be found on its home page at http://www.dcs.qmw.ac.uk/research/distrib/Djinn/

The Questionnaire

This questionnaire is aimed at users, or potential users, of digital video production and content-delivery technologies, especially those in the television industry. We are interested in hearing about current experiences with these systems, and acquiring knowledge of specific requirements in the areas of distribution, real-time guarantees and configurability.

The questionnaire is divided into five sections, with a total of 35 questions, mostly in a multiple-choice format. The last six questions ask for some personal details about the respondent -- please fill this in if you don't mind us contacting you in the future with further questions. All personal details will remain confidential. If any of the terms used in the questionnaire are unclear, please do not hesitate to contact us for clarification.

If your Web browser doesn't support forms (although most, if not all, should do so), you can fill out the plain text version of the questionnaire and return it by email, to scott@dcs.qmw.ac.uk, or by regular mail to:

Distributed Systems Group
Attn: Scott Mitchell
Department of Computer Science
Queen Mary and Westfield College
Mile End Road
London E1 4NS
ENGLAND

phone: +44 (171) 975-5245
fax: +44 (181) 980-6533

Section 1: Deployment of digital communication/processing technology

1.1. To what extent are digital processing and communication systems used in your production, post-production and content-delivery activities?
None
A little
Some
A lot
Completely

1.2. Which areas of your business make the most use of these technologies?

1.3. In five years time, the amount of digital technology using in your business, compared to today, will:
Greatly decrease
Decrease
Remain the same
Increase
Greatly increase

1.4. In five years time, which areas of your business will make the most use of these technologies?

1.5. If you are using digital networks for communication between distributed (i.e., physically separated) production sites, outside broadcast units, etc., are you using public or private, dedicated networks? Please give details.

1.6. With the deployment of public wideband network technologies such as ATM and B-ISDN, do you anticipate that your use of public digital networks over the next five years will:
Greatly decrease
Decrease
Remain the same
Increase
Greatly increase

1.7. Please enter any general comments you might have about this section:

Section 2: Distribution Requirements

2.1. What level of distribution (in terms of collaboration between users and equipment at physically separated locations) is currently present in your production, post-production or content-delivery systems?
None (dedicated, centralised systems only)
Some (distribution within a single site)
Lots (multiple, co-operating remote sites)

2.2. If you answered Some or Lots to the previous question, please give details here:

2.3. In the next five years, your use of distributed systems is likely to:
Greatly decrease
Decrease
Remain the same
Increase
Greatly increase

2.4. Please enter any general comments you might have about this section:

Section 3: Real-time Requirements and Guarantees

Considering the production/post-production and content-delivery environments separately, what are acceptable upper-bounds on the following quantities?

3.1. End-to-end latency (delay):

A. Production/post-production
less than 1ms
1-10ms
10-100ms
0.1-1s
more than 1s 		B. Content Delivery
less than 1ms
1-10ms
10-100ms
0.1-1s
more than 1s

3.2. Jitter (variation in end-to-end latency):

A. Production/post-production
less than 1ms
1-10ms
10-100ms
0.1-1s
more than 1s 		B. Content Delivery
less than 1ms
1-10ms
10-100ms
0.1-1s
more than 1s

3.3. Synchronisation delay (the relative time difference between two synchronised streams, such as audio and video, or two overlaid video streams):

A. Production/post-production
less than 1ms
1-10ms
10-100ms
0.1-1s
more than 1s 		B. Content Delivery
less than 1ms
1-10ms
10-100ms
0.1-1s
more than 1s

3.4. Error rate, measured as lost or corrupted frames per second:

A. Production/post-production
zero
less than 1
1-3
3-5
more than 5 		B. Content Delivery
zero
less than 1
1-3
3-5
more than 5

3.5. Would you describe these bounds as hard (they must never be exceeded), or soft (they must never be exceeded on average)?

A. Production/post-production
Hard
Soft 		B. Content Delivery
Hard
Soft

3.6. Please enter any general comments you might have about this section:

Section 4: Configuration Management

Assuming the use of distributed, real-time digital production and/or content-delivery systems:

4.1. System reconfiguration (of active components, inter-component connections, or stream properties) occurs:
Rarely (days, weeks)
Occasionally (daily)
Regularly (hours)
Frequently (hourly)
Continuously (minutes)

4.2. Configurability will be an essential feature of the digital studio of the future.
Strongly disagree
Disagree
Not sure
Agree
Strongly agree

4.3. The ability to reconfigure parts of the overall distributed system, without disrupting the ongoing operation of other parts, is important.
Strongly disagree
Disagree
Not sure
Agree
Strongly agree

4.4. Configuration changes involve changing the settings of multiple interacting components/connections/streams.
Never
Sometimes
Often
Usually
Always

4.5 When multiple related changes are made to a configuration, it is essential that all of the changes are completed successfully.
Strongly disagree
Disagree
Not sure
Agree
Strongly agree

4.6. Constraints or restrictions on the allowable configurations of the system exist and must be maintained, even in the face of operator error or equipment failure.
Strongly disagree
Disagree
Not sure
Agree
Strongly agree

4.7. Please enter any general comments you might have about this section:

Section 5: Personal Information

Please fill in the following if you do not object to us making further contact with you later:

5.1. Name:

5.2. Company/Organisation:

5.3. Email address:

5.4. Phone number:

5.5. Fax number:

5.6. Please enter any general comments about this questionnaire:

Last modified: Mon Mar 2 17:46:34 GMT 1998
Scott Mitchell <scott@dcs.qmw.ac.uk>
Valid HTML 3.2!