Definitions for Desktop Software, Server-based Enterprise Videoconferencing Systems
The Desktop Software,
Server-based Enterprise Videoconferencing module provides in depth coverage of
these software, server-based personal videoconferencing systems, typically
deployed to a large group of employees throughout an enterprise (or on an
enterprise-wide basis).
Desktop/Personal systems are
designed to provide videoconferencing capabilities to individuals and are
generally referred to as Desktop, Personal, or Executive systems. Several
options exist for provisioning this type of service, including personal or
desktop systems, integrated IP-PBX endpoints, software and web conferencing
based products with video capabilities (software client type offerings for
enterprise deployment for example), and
even videophones. The coverage in this T3i Group database module will
concentrate on the software, server-based enterprise videoconferencing systems
that are typically deployed to a large number of users throughout an
organization, and which generally require only the software, a PC and a USB (or
other) camera attached to the user’s PC.
T3i Group’s comparative
database module provides detailed information on each vendor’s individual
product offerings so all products can be viewed and compared on an equal
footing. Each module includes approximately 45 fields of information, each of
which is defined as follows:
Company Name: Provides
the name of the videoconferencing product vendor
Headquarters Location: Lists the city and state where the vendor’s headquarters are located
Main Telephone Number: The primary telephone number at the vendor’s
headquarters location
Internet Address: The
vendor’s web site address
Product: The
model name for each of the vendors’ products being covered
Product Introduction Date: The date that the vendor first introduced or first
started shipping the product
Type of Equipment: Describes
the particular type of equipment being offered (such as Hardware with
Server-based software; Software, Server-based; Software, Web-client; or
Software, Client- or Server-based)
Date Information Verified: The actual date when the product information was last
checked and verified to be correct and current
Bandwidth Requirements: May state the bandwidth (or bandwidth range) supported
(or required) by the product for either or both IP/ISDN connectivity, or could
state the minimal or optimal bandwidth requirements for that product
Audio Standards Supported: Lists the audio standards (as defined by the
International Telecommunications Union (ITU)) supported by each product, along
with the audio range.
G.711-a
56/64Kbps bit stream for 3.4KHz audio
G.722-a 48/56/64Kbps bit stream for 7KHz audio
G.722.1-a 24/32Kbps bit stream for 7KHz audio
G.722.1 Annex C-the ITU’s adoption of Polycom’s Siren
14-14KHz audio
G.723.1-a 5.3/6.4Kbps bit stream for 3.4KHz audio
G.728-a 16Kbps bit stream for 3.4KHz audio
G.729-an 8Kbps bit stream for 3.4KHz audio
AAC-LD-MPEG2
Advanced Audio Coding-Low Delay format for 7KHz or 14Khz audio; also MPRG4
AAC-LD for 20KHz audio (CD quality)
Audio range is
stated as 3.4KHz, 7KHz, 14KHz, 16KHz, 20KHz, etc.
The user should keep in mind
that typical human hearing range is from 20Hz to 20KHz; therefore a
videoconferencing system supporting audio capability below 20Khz will provide
something less than the full available range that the human ear can detect.
Also keep in mind that typical telephone quality audio is at 3.4KHz, while CD
quality audio is at 20Khz.
Full Duplex Audio: Full
duplex audio means that the videoconferencing system allows conference
participants at multiple locations to speak at the same time and be heard at
all locations. In systems that do not support full duplex audio, a person
speaking at one location may override and cut off those speaking at other
locations (as the audio can only flow in one direction at a time).
Video Standards: To begin, there are three high level, umbrella standards issued by the
ITU for videoconferencing. These are the H.320, H.323 and H.324 standards, and
they are broadly defined as follows:
H.320 – the public switched telephone network (PSTN)
standard for video over ISDN (BRI or PRI), and also applies to dedicated
network connections such as T1 and satellite based services
H.323 – the standard for video over a LAN or IP network
H.324 – the standard for transmission over Plain Old
Telephone Services (POTS), or audio telephony networks
Under these umbrella
standards are several individual standards, each of which addresses various issues
related to communications and video transmission, and includes the following:
H.221
– Under the H.320 umbrella, defines the transmission frame structure for
teleservices from 56/64Kbps to 2 Mbps
H.223
– Multiplexing protocol for low bit rate multimedia connections, such as
transfer of a combination of digital voice/audio, digital video/image, and data
information over a single communications link
H.224
– Real time control protocol for simplex (one-way) use of a data channel using
H.221 (for applications like far end camera control)
H.225
– Multiplexing transmission formats for media stream packetization and
synchronization on a non-guaranteed QoS LAN
H.230
– Under H.320, for controlling synchronization of video frames
H.231
– Multipoint Control Unit (MCU) to bridge 3 or more conferencing systems at
rates to 2Mbps
H.241
– Defines extended video procedures and control signals for multimedia
terminals
H.242
– Under H.320, defines protocols for dall set up disconnect at rates up to
2Mbps
H.243
– Under H.320, defines control procedures and protocols for MCU call set up at
rates up to 2Mbps
H.244
– Deals with H.221 bonding, or the aggregation of multiple 56/64Kbps channels
H.245
– Under H.323, relates to control of multimedia communications
H.261
– Video codec for audiovisual services at px64Kbps (supporting QCIF/CIF
resolutions); defines how the picture information is compressed and coded for
transmission over low bandwidth networks
H.261
Annex D – Protocol for transferring high quality still images at 4CIF
resolution
H.263
– Video coding for low bit rate communications, designed for lower transmission
rates (at 64Kbps to 128Kbps)
H.263+/++
- Represent two higher levels of the H.263 standard that include improved
encoding efficiency and improvements against data loss during transmission
H.264
– A video codec standard that greatly improved image quality at significantly
reduced bandwidths; this standard effectively made it possible to transmit the
same quality video at half the bandwidth (as compared to systems that did not
support the H.264 standard)
H.281
– Far end camera control protocol for videoconferences using H.224
H.331 – For broadcast mode videoconferencing
H.350
– Relates to storing and retrieving information from enterprise directories (also
referred to as LDAP-Lightweight Directory Access Protocol); on systems
supporting this protocol it is possible to link to existing corporate contact
directories to set up videoconference calls, making it easier for the users
It should be noted that the
comparative database modules list all of the standards that appear in the
available literature for each vendor’s product (or for which the vendor has
notified T3i Group of their support for that standard). There may, however, be
some products listed that support more standards than are actually shown in the
database (since some vendors do not see the point of listing each and every
standard supported on their product, but instead mention only those standards
that are of major significance).
Data Standards: The data standards that are covered under this
heading, which are:
H.239
– Endpoints that support H.239 can receive and transmit multiple, separate
media streams, usually for voice, video and data collaboration
T.120
– A family of standards that define the protocols for data collaboration (such
as file transfer, still image transfer, shared whiteboarding, etc.)
T.140
– Protocol for multimedia application text conversion (online chat) over an IP
network, used by both H.323 and SIP systems
Additionally there are
various encryption standards that are covered in a subsequent attribute field
of the database.
Interoperability: States
whether the system supports connection to (and interoperability with) other
standards based videoconferencing systems (such as traditional desktop/personal
and room/group endpoints)
Encryption: There
are a few key standards that relate to data encryption designed to help secure
the multimedia conference sessions, using Advanced Encryption Standard (AES)
based offerings, as adopted by the ITU, as follows
H.233
– The ITU’s data encryption standard for real time multimedia (applicable to
H.320, H.323, and H.324)
H.234
– Encryption key management and authentication system for audiovisual services
used by H.320 devices
H.235
– Security and encryption for H.323 and other H.245 based multimedia terminals
Microsoft Office Integration: allows users to initiate videoconferences and perform
other functions from within a Microsoft Office application (Word, Excel,
PowerPoint); with this capability, a user doesn’t have to exit an application,
then go and set up a videoconference
Microsoft Outlook Integration: allows users to access, schedule and set up
videoconference meetings using Microsoft Outlook, as well as get meeting
reminder notifications
Lotus Notes Integration: allows users to access, schedule and set up
videoconference meetings using Lotus Notes
Video Resolution: Video
resolution is a measure of image quality and clarity. The higher the
resolution, the better the quality and clarity. Video resolution is measured as
the number of pixels across times the number of pixels high (where pixels are
individual colored dots that are used to form the images presented on screen).
While higher numbers (and therefore higher resolutions) mean better pictures,
they also mean more memory/bandwidth to store and transmit the information. In
some cases there may also be tradeoffs in maximum frame rate (the speed at
which the video images are refreshed expressed as frames per second or fps) and
the maximum resolution. As an example, standard definition (SD) analog TV
offers 480i resolution (at 720x480 pixels) running at 30fps; extended
definition (ED) TV offers480p resolution (at 720x480 pixels) also running at
30fps; high definition TV offers 720p resolution (at 1280x720 pixels) and
ultrahigh definition (HD) TV offers 1080p resolution (at 1280x1080, 1440x1080,
or 1920x1080 pixels). The list of video resolutions offered and supported on
the different systems consists of the following (which includes resolution
levels applicable to still image/graphic files):
QSIF
– 180x120
SIF
– 352x240
4SIF – 704x480
QCIF – 176x144
CIF (or FCIF) – 352x288 (about the same as VHS quality
video)
4CIF – 704x576 (close to broadcast or DVD quality video)
QVGA – 320x240
Half VGA – 640x240
W288p
– 512x288
400p
– 528x400
W448p
– 576x448
VGA
– 640x480
W576p
– 1024x576
SXGA
– 1280x1024
XGA – 1024x768 (typical PC/laptop display)
480i/p – 720x480
720p – 1280x720 (high definition)
1080p – 1920x1080, 1280x1080, or 1440x1080 (ultra high
definition)
Video Frame Rates: Defines
the speed at which the video image is displayed, so 30frames per second (30fps)
means that 30 separate frames are changed every second. As a basis to
understand this term, standard definition TV typically runs at 30fps while high
definition TV typically runs at 50/60 fields per second. The higher the frame
rate the smoother the video image. Lower frame rates could result in less
fluent video movement and very low frame rates could result in a rather choppy
appearing video. Typical frame rate offerings range from 5fps to 30fps.
Inputs: Provides
information on the audio, video and ancillary inputs supported by the
videoconferencing system. Typical inputs would be provided for cameras,
microphones (or audio device), a VCR/DVD, or other device. Since these systems
are typically PC-based, the number and type of inputs available generally
depends on the PC utilized.
Outputs: Provides
information on the audio, video and ancillary outputs supported by the
videoconferencing system. Typical outputs would be provided for
monitors/displays, audio speakers, a VDR/DVD, or other device. Since these
systems are typically PC-based, the number and type of inputs available
generally depends on the PC utilized.
Network Interfaces: This
section identifies the basic type of network connections or interface options
supported by the video systems, generally listed as IP (which can be IP, LAN,
DSL or cable modem), and SIP (session initiation protocol)
Display/Monitor Type: Lists the type(s) of monitor/display unit(s) supported
by the videoconferencing system; typically these systems utilize a PC’s display
Number of Displays: States
how many displays/monitors can be connected on the system; all systems require
at least one display, some support a second display (for data presentations or
other uses)
Camera Type: several types of cameras can be used on videoconferencing systems,
although not all types are supported on all systems; also keep in mind that
some video systems come as integrated or packaged units with the camera (or
cameras) included, while others allow (or more likely require) the user to
acquire a camera of their own choosing (so long as it is supported by the video
system being used); some of the more common types of cameras available include
the following:
USB
Camera – typically utilized on PC-based personal/desktop systems, these are
usually fixed focus (and lower quality devices), however there are PTZ (pan,
tilt, zoom) versions of USB cameras available and even automatic face tracking
options are available
Fixed
Focus Camera – cameras with a fixed viewing angle and focal length; may have a
manual focus adjustment
Pan,
Tile, Zoom (PTZ) Camera – cameras that can pan, tilt and zoom, typically with
some remote control capability so the user can maneuver the camera angle and
focus, or utilize defined preset positions to automatically move the camera to
a particular object or point in a room
Voice
Tracking Camera – this is typically a more advanced version of a PTZ camera
that actually changes it sfocus based on who is currently speaking in the room
HD
(High Definition) Version Cameras – there are also HD versions of Fixed Focus,
PTZ and Voice Tracking PTZ cameras available, which are also required to
support a truly HD videoconferencing system
Another factor to consider is
whether the camera is a 1 chip (1CCD) or 3 chip (3CCD) device, which indicates
the number of computer chips the camera uses to process colors. For a high
(broadcast) quality video, a 3CCD camera is needed, however, for a lower level
web video conference, a single chip (1CCD) camera may suffice.
Many videoconferencing
systems also support the use of optional document cameras which can be used to
transmit still images during a video conference, for example as part of a
presentation (to show a product or some document).
Number of Cameras: Indicates
the number of cameras supported by the videoconferencing system (which could
also be shown as the number of main cameras and document or auxiliary cameras)
Camera Controls: Typical
camera controls would be manual focus, pan/tilt/zoom, and presets (near and far
end) that allow the users to preselect particular camera settings to view
sections of a room or objects in a room based on the established presets
High Definition: Identifies
whether or not a videoconferencing system can be operated in true high
definition (HD) mode, running at 720p or 1080p resolution; these systems
require HD codecs, HD cameras and HD displays (with some also offering specialized
HD audio components)
Data/File Sharing: Indicates
whether or not the videoconferencing system supports the sharing of data files
or presentations (such as spreadsheets or other documents) on screen during the
video conference
Additional Data Window: For systems that do support Data/File Sharing, some
require a separate data display monitor device to view this information while
others allow the videoconferencing system’s main display to open up a data/file
sharing window for that purpose
Broadcast Mode: allows
one member of a multipoint videoconference to operate in broadcast (or
presenter) mode and control the proceedings such that the presenter and/or the
presentation materials will be seen on the displays of all conference
participants (as an example)
Multipoint: Videoconferencing
systems operate in either point-to-point mode (with two sites directly
connected to each other) or multipoint mode (allowing multiple sites to
participate in the same conference call). Multipoint conferences can be accommodated
in two basic ways – in some cases all sites are interconnected to all other
sites; the alternative is that all sites are interconnected via a Multipoint
Control Unit (MCU). Additionally, MCU functionality can either be embedded into
the videoconferencing system software or provisioned via an external MCU
product offering.
PC Required: these
systems are software based and generally require the user to provide a PC and a
camera
PC Requirements: this field
lists the basic requirements for the PC, such as type of processor, type of
operating system, Internet browsers supported, etc.
SIP: States
whether or not the videoconferencing system supports the Session Initiation
Protocol (SIP), which is used to provide presence indication, among other
things, so that the videoconference setup can be more tightly integrated into
things such as Instant Messaging, as well as support integration with other
applications. Pure IP-based products may support the SIP signaling protocol for
Internet conferencing, telephony, presence management, events notification, and
instant messaging. SIP is used for call setup and teardown, routing requests
between locations, and to initiate information transfers, as well as to enable
translation of text names, email addresses, and phone numbers into IP
addresses.
Continuous Presence: Support of continuous presence allows a user in a
multisite videoconference call to be able to see the other participants in the
meeting at the same time – on multiple monitors or using multiple display windows
on a single monitor, and it is accomplished by transmitting multiple
simultaneous images
Picture in Picture (PIP): States whether or not the videoconferencing system
supports the Picture-in-Picture feature that allows two (or more) images to be
shown on a single display at the same time, one (or more) of which is usually
shown as a small (inset) window; some systems also support Picture and Picture
which typically shows two images side by side using a split screen
Split Screen: This
capability is typically used on single monitor systems so that the far end
participant and a data presentation (for example) could both be seen at the
same time, or so participants from two remote sites could be displayed on the
monitor at the same time
Multilingual: Defines
whether or not the system supports multilingual services, such as for the user
interface and call setup screens (which could be on the users monitor or
accessed via an online web portal); this is not to be confused with
multilingual services that would provide language translation among multiple
participants or other such services
Record and Playback: States whether or not the videoconferencing system
supports a video recording capability which would allow users to record the
videoconference session, store (or archive) it, and then access it at a later
time for playback
User Interface: Provides information on the type of user interface offered on the
system for call setup and control; typical user interface offerings include the
computer keyboard and mouse used with an onscreen menu, a web portal, etc.
Additional Capabilities: This field is used to list any additional capabilities
or optional accessories that may be offered on the particular videoconferencing
system (that have not been addressed in any of the previous data fields)
Pricing: States
the basic list price (in US$) for the videoconferencing system and its primary
components and options; where available, typical discounts and/or street prices
are also shown
Strengths: List
the strengths of the videoconferencing system and/or the vendor as compared to
other like products available in the market
Weaknesses: List the weaknesses of the videoconferencing
system and/or the vendor as compared to other like products available in the
market