The Technology

Transmission Protocols

Marshall University will support connectivity in two formats. The primary videoconferencing protocol supported shall be H.323 video over IP for in-state conferencing. The second supported protocol shall be H.320 video over ISDN for out of state and gateway connectivity to independent sites off the West Virginia network. Legacy support of ATM video will continue as long as resources allow.

1. H.323 video over IP (Internet Protocol)

H.323 is the commonly accepted International Telecommunications Union (ITU) standard for video over the Internet. The H.323 standard allows the university to transmit videoconferencing over the same infrastructure that supports the world wide web and other internet services. By moving video to IP, Marshall is able to maximize cost savings by focusing all its’ resources on maintaining the highest quality IP network rather than spreading support over several parallel networks. In addition, H.323 is rapidly becoming the standard protocol for telecommunications vendors, including Verizon, and is the standard for the Internet 2 research network. H.323 has both advantages and disadvantages. By moving videoconferencing to the Internet, bandwidth efficiency and the ability to add or move videoconferencing devices to any Internet connection on a network is maximized. However, the high bandwidth needs of videoconferencing require very robust networks and bandwidth management to ensure solid connections.

2. ISDN (Integrated Services Digital Network)

Marshall will continue to support H.320 video over ISDN to provide connectivity to outside organizations. ISDN uses digital phone lines and is still the most commonly used method of out of state videoconferencing. The advantage of ISDN is that bandwidth is dedicated to the call so there is no risk of loss of quality from competing conferences.  ISDN connections are available only through the Multipoint Conferencing Unit.

Hardware Specifications and Selection

Because faculty, staff, and students with varying degrees of technical expertise will operate these systems, simplicity and function must go hand in hand. PolyCom has been selected as the university standard due to its ease of operation, remote maintenance capabilities and web interface, high quality video, and affordability. The PolyCom products have internal video source mixing, switching, and control features within codecs that simplify operation by reducing the total number of pieces of equipment and complexity of both operation and maintenance.

PolyCom is an industry leader and recently acquired Accord Systems, a top manufacturer of Multipoint Conferencing Systems, and the manufacturer of the Marshall MCU. This reduces the number of support calls and eliminates “finger pointing” between vendors on service calls.

Coder/Decoders

PolyCom Viewstation 323

PolyCom Viewstation FX

Suitable for Cart Based portable systems, executive conference rooms, and most classroom applications. With one onboard camera and two auxiliary inputs it is fully equipped for teaching applications but can also be cart based. Includes internal multipoint capabilities, high bandwidth capabilities, and voice tracking. The high high-end, high-cost PolyCom codec used when high quality portable connectivity is needed.

PolyCom Viewstation 4000

Suitable for rack mounted classroom applications with the use of two external cameras and a third auxiliary input. The VS4000 is the most common classroom codec at Marshall University and the base of the Distance Learning Video Classrooms.

PolyCom ViaVideo

Peripheral Devices

Beyond the core hardware and software, room configurations may vary considerably in terms of specific manufacturers and models.

• Video Switching devices: Most rooms are equipped with AMX touch panels that allow the faculty member to choose which video course the students will see.
  
  

• Document Camera: The PolyCom Systems will work with almost any variety of document cameras. The video output of the document must be S-Video to connect to the codec. Document cameras with A/V in and out for adding additional video devices are convenient. Several models also include built in computer scan converter that make it possible to connect a computer or laptop device without additional hardware.
  
  

• Video Cassette Recorder: The PolyCom VCR input is standard composite video (RCA connector) with left and right audio. One VCR will operate as both playback and receive deck but it is not possible to do simultaneous playback and record without a second VCR and additional hardware.
  
  

• Scan Converter: Scan converters allow a computer output to be fed into the video codec. There are many models available that vary in price from under $300 to several thousand. Regardless of cost, the computer screen image will never be completely replicated on the video screen. Small fonts and images with fine lines become blurry and unreadable. This is particularly difficult with websites and spreadsheets. It is therefore more important to focus on features that provide the flexibility to zoom in on a part of the screen and pan across. Some of the lowest cost device offer the best zoom/pan features and even many low cost document camera’s now provide this feature.

• Computer: A dedicated PC or laptop is a high priority in any teaching classroom or in a space used for frequent presentations.
  
  

• Television Monitors: Minimum of 27” television monitors equipped with S-VHS video inputs and video loop through. Top mounted controls are not desirable. Vertically flat screen televisions tend to work better in most circumstances where glare is a concern.