Table 1: Multimedia applications
APPLICATION
MEDIA
A=
Audio
, V=
Video
,
T=
Text
, I=
Images
,
G=
Graphics
A, V, T, I
DESCRIPTION
Education/ Training
A live or taped video instructional session locally at a station or
across a network. This involves transfer of audiovisual and
textual instructions.
A live or taped video instructional session locally at a station or
across a network. This involves transfer of audiovisual and
textual instructions. The interaction may be via voice, text or
graphics.
This is dispensing of information such as legal, tourist, consumer
catalogs, dictionaries etc... These kiosks typically have minimal
interaction with the user; mainly instructions and commands.
Number transfers along with documents such as checks, money
orders, internal papers etc...
Stored or real-time capture of X-Rays, CAT scans, reports etc...
with ability to do history, compare and micro and macro
searches.
Search and retrieval of texts, audio and video cassettes.
Ability to view a neighborhood, block, street, house and interior
of home remotely.
Ability to leave audiovisual messages along with textual
messages.
Cable company maintains library of movies which can be
selected and played-back at viewer's convenience.
Similar in concept to real estate with ability to book travel,
lodging and boarding in one call.
Standard engineering CAD / CAM with the ability to voice-
annotate and have on-line graphics help and notes as pop-up
boxes.
Video conferences, concurrent CAD/CAM etc...
Ability to reconstruct, edit and create images annotated with
audio and text. The images may be sequenced into a video clip.
Ability to parse satellite images of the atmosphere into weather
reports.
Interactive Education/
Training
A, V, T, I, G
Information kiosks
A, V, T, G
Banking
T, I
Medical Info. systems
V, I, T, A
Library
Real Estate
I, T, V
A, V, I, T
Electronic Mail
T, A, I
Home Video Distribution
V, A
Travel Agents
A, V, I, T
CAD/CAM
T, G, A
Electronic Collaboration
Advertising
A, V, T
V, A, I, T
Weather
I, T
There are several issues with multimedia, most notably
compression, synchronization
and
network transparency
.
Multimedia applications typically consume a lot of
disk space for storage and current storage devices such as
Hard Disks, floppy disks, CD-ROMs are not capable of
storing massive amounts. Moreover, these storage devices
have a very slow transfer rate (read, write). Motion video
requiring 75 Mbps transfer rate cannot be sustained using
a CD-ROM without some compression techniques.
Synchronization of multimedia objects is an important
issue [8]. An object is a unit of data which may be a pixel,
encoded audio, the multimedia document itself, etc...
Synchronization can be at different granularity's. An
example of synchronization is voice and video streams;
the voice accompanying a video clip needs to be
synchronized to the picture. This issue is currently being
addressed in the multimedia community.
Most multimedia applications will need network
support [9]. Videoconferencing [7], distributed training,
etc... require the use of a network. Insofar as the network
is concerned, the only difference between multimedia and
other applications is the integration of voice, video and
data on the same network. Imaging can be modeled as
bursty data and hence does not require any additional
service of the network.
Almost all data transmission is asynchronous in nature.
It is unpredictable and of varying duration. Most local
area networks are optimized for high throughput, bursty
data transmissions over a shared medium with little or no
latency constraints. If the network is lightly loaded, and a
station applies a large load to the network, it will be able
to transmit the load with minimal delays. However, if the