Definitions for Desktop/Personal Videoconferencing Systems

The Desktop/Personal Videoconferencing modules provide in depth coverage of the traditional videoconferencing equipment market, from the low end to the high end systems.

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 the T3i Group database will concentrate on traditional Desktop or Personal videoconferencing systems (hardware and software based) that can typically deployed to individual users throughout an organization, and will also exclude telepresence systems as these will be covered in a separate module.

T3i Group’s comparative database modules provide 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 40 fields of information, each of which is defined as follows:

Company Name: Provides the name of the videoconferencing product vendor

U.S. Headquarters Location: Lists the city and state where the vendor’s U.S. headquarters are located

Main Telephone Number: The primary telephone number at the vendor’s U.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 Desktop (Software), Desktop (Hardware), Portable Set Top, Portable Rollabout, etc.)

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.239 – Endpoints that support H.239 can receive and transmit multiple, separate media streams, usually for voice, video and data collaboration

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: In addition to the H.239 standard (previously included under Video Standards), which allows for separate data streams to support data collaboration, there are a couple of significant data standards that are covered under this heading, which are:

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 the next attribute field of the database.

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

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 include 15fps, 30fps, and 50/60 fields per second.

Inputs: Provides information on the audio, video and ancillary inputs supported by the videoconferencing system. Typical inputs would be provided for cameras, microphones, document/auxiliary cameras, a PC or other data device, a VCR/DVD, or other device; note that some videoconferencing systems are sold as complete, fully integrated units consisting of the video codec, camera, display, microphone and speakers and so may not have any additional inputs

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; note that some videoconferencing systems are sold as complete, fully integrated units consisting of the video codec, camera, display, microphone and speakers and so may not have any additional outputs

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), ISDN (which could be BRI or PRI, or both), and V.35 (for a private line network)

Display/Monitor Type: Lists the type(s) of monitor/display unit(s) supported by the videoconferencing system; typical desktop systems may come as an integrated unit with a built-in display, utilize a PC’s display, or require an external display (which could be a standard TV monitor or a particular display with a required resolution rating); typical room/group systems utilize external displays (which again could be a standard TV monitor or a particular display with a required resolution rating); also note that some vendors include the display/monitor(s) as part of the videoconferencing system package, while others may allow the user to select their own compatible display/monitor(s) (or reuse existing equipment)

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 sues), and some systems support multiple displays to allow for more conference participants to be viewed from one or multiple locations

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 sometimes 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; this application would generally require a PC or other device to be integrated into or connected to the videoconferencing system

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 codec or provisioned via an external MCU product offering.

PC Required: (not generally applicable to Room/Group systems); this field typically applies to Desktop/Personal systems that are software based and require the user to provide a PC on which to run the video software; many videoconferencing systems also allow the use of a PC to support data/file sharing but in those cases the PC isn’t required to provide the videoconferencing capability itself

PC Requirements: (again, not generally applicable to Room/Group systems); on those systems that do require a PC to provide the videoconferencing capability, 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 integrated keypads, remote control units, a computer mouse used with an onscreen menu, a touch control pad, 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