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Evolving Video Conferencing Technologies:
New Opportunities for Integration
Timothy M. Logan
Presented at CAUSE 98
December 10, 1998
As the connectivity, affordability, and functionality of desktop and small room video conferencing systems have improved in the past two years, Baylor University has begun to incorporate distance education and video conferencing capabilities into technology classrooms as standard equipment. Integrating video onferencing into multimedia classrooms allows guest speakers for classes, interactive collaborative projects between students, and experimentation with new applications of video technology into the curriculum. Emerging telecommunications technologies, the importance of standards-based network design, and the development of a suitable network infrastructure are all critical in an effective implementation strategy for video conferencing for innovative teaching and learning applications.
Evolving Video Conferencing Technologies:
New Opportunities for Integration
Timothy M. Logan
The major indicator of the success of a technology is the point when the client base ceases to treat the technology as a novelty and begins to expect and demand its availability as a matter of course. Examples within the past decade include graphical user interfaces, Email, Internet connectivity, CD-ROM access, and classroom display technology. The establishment of reliable video conferencing standards, the decreasing costs of desktop and portable video systems, the availability of ISDN service, and increasingly robust data networks are creating an atmosphere where video conferencing is making the transition from a curiosity to an expectation. Existing media-capable projection classrooms offer an excellent venue for incorporating this burgeoning technology into appropriate instructional settings and for experimenting with teaching and learning models that include video conferencing as an integral part of instruction, rather than a specialized mode of information delivery.
A significant element of instructional technology during the past decade has been on the establishment of technology-rich, media-capable classrooms for enriched teaching and learning environments. Such classrooms incorporate a computer, projection system, audio reinforcement, control systems when appropriate, and additional audio, video, and network resources as VCRs, videodisc players, audio cassette players, CD-ROM drives, document cameras, Internet connectivity, DVD players, and other devices appropriate for the instructional needs of the teachers in the classroom. A parallel, but frequently separate, initiative on campuses has been the creation, at significant expense, of high-quality video conferencing facilities for distance education. video conferencing classrooms have typically focused on high-bandwidth CODECs installed with elaborate audio, video, and control systems to optimize the delivery of instruction from the origination site to one or more remote classrooms. Currently, however, the increasing availability of inexpensive video conferencing systems for desktop computers and all-in-one portable systems, coupled with the emerging H.323 standard for video over IP networks, allows for the integration of distance education via video conferencing into existing technology classrooms, and the application of new models of distance education via collaboration and connectivity.
Recent video conferencing product offerings, coupled with newly adopted transmission standards, have radically changed the financial equation for delivering live, interactive video to the classroom. Many manufacturers now have available very affordable desktop and small classroom video conferencing systems at a much lower price than previously available, while retaining a level of quality, connectivity, and ease of use that support effective classroom use. In addition, the production of H.323-compliant systems has reached a point that video conferencing systems can be added to existing classrooms, with video conferencing available over the campus IP data network. Lastly, the advent of standards and affordable video conferencing systems has increased the use and broadened the definition of distance education to incorporate less formal but equally useful applications of interactive video as part of the instructional process.
The quality, variety, and affordability of desktop computer video conferencing systems have reached the point that a computer in a presentation classroom can support video conferences of suitable quality for numerous distance education applications at a surprisingly low cost. Industry competition in the desktop market has improved the quality of transmission, while lowering the cost to a level within the reach of educational institutions. In addition, the widespread acceptance of video conferencing standards, notably H.320 for ISDN and, more recently, H.323 for IP networks, has ensured interoperability between vendors. All of the major vendors support H.320 and H.323 video conferencing standards, rather than proprietary connection strategies which limit the interoperability and connectivity that make video conferencing systems most valuable. The reliance on standards ensures that desktop video conferencing units can communicate over the public switched telephone network via ISDN lines or over the campus local area network via IP to any other standards-compliant teleconferencing unit, including room system CODECs and desktop units, regardless of vendor. Given the broad acceptance of the H.320 standard, as well as the developing H.323 standard, an institution can invest in video conferencing systems with confidence that the systems will be able to communicate with a broad range of other systems and resources
Powerful and flexible video conferencing connectivity is now available at a price comparable to other classroom technology components such as document cameras and computer data video projectors. Adding a video conferencing board and associated software to an existing technology classroom computer is easily accomplished for initial connectivity. Portable all-in-one systems provide an ideal solution for incorporating interactive and streaming video into the classroom, transforming the classroom from an isolated, unidirectional delivery facility into an interactive video environment.
An H.320 ISDN BRI video conferencing package for an existing classroom computer can be purchased at or near $2,000, which includes hardware and software, and probably an NT1 (needed for connection to a BRI line), an inexpensive video camera, or both. It is important to note that this purchase should not be considered as a costly addition to a technology classroom, but rather as a very low cost entry point into the realm of video conferencing. The basic video conferencing system as described above, coupled with a connection to an ISDN BRI line, will provide connectivity to other video conferencing systems at 128Kbps, the minimum acceptable level for reasonable quality video and audio. Increased bandwidth options, up to 3 BRI lines (384Kbps) are available at substantially greater cost, as the inverse multiplexing of multiple phone lines remains a costly item. While the basic system may have significant limitations in terms of video inputs and student audio, it provides sufficient quality to bring guest presenters into the classroom and to support interactions between students at other institutions. In addition, since the desktop video conferencing systems provide for at least one audio and one video input as part of the host computer, additional equipment, such as camcorders, microphone mixers, and other A/V sources can be connected into the system through external audio/video switches. In fact, the desktop system can be adapted to handle a huge variety of video conferencing peripherals, as time and money dictate. Experimentation at Baylor University has demonstrated the ability of the desktop computer to control multiple external pan-tilt-zoom cameras, document cameras, VCRs, and videodisc players through RS-232, RS-485, and infrared control.
An entirely new group of products has recently been added to the mix of video conferencing solutions available for campus use. Joining desktop video conferencing and large room systems are products that are easily portable yet highly functional. The market leader in this arena was the PictureTel SwiftSite, an all-in-one 128Kbps settop CODEC and pan-tilt-zoom camera that was lightweight, transportable, and simple to connect to televisions or projection systems. This product segment has grown tremendously in terms of connectivity and functionality, with products capable of 384Kbps, V.35 connectivity, H.320 and H.323 encoding and transport, and even including an integral 4-port multipoint conferencing unit (MCU) to facilitate 3, 4, and 5-way video conferences without external hardware. Examples include PictureTel's SwiftSite II, Polycom's ViewStation series, RSI's VideoFlyer, and VTEL's Settop 250, among others. These products offer quality and functionality previously only available with an investment in hardware costing 10 times as much as current prices. The portable systems are an ideal choice for integration into existing technology classrooms at an affordable price, and they can support surprisingly complex installations of video and audio sources and system control. The combination of low cost devices at reasonable prices with flexible bandwidth requirements using both ISDN and IP transmission protocols makes the incorporation of video conferencing capabilities into the classroom extremely affordable and effective.
The inclusion of video conferencing capabilities into technology classrooms allows institutions to significantly increase the value of existing high-end facilities while entering the world of video conferencing at a fraction of the cost of a dedicated classroom. As the utility and value of video conferencing becomes apparent through use and experimentation, the desktop or portable system can be adapted and augmented to meet increasing needs and expectations, until such time as a high-speed CODEC becomes a necessity. As a starting point, however, a desktop video conferencing system and an ISDN BRI connection, or an integrated portable unit using ISDN or IP, both offer outstanding opportunities for system growth and experimentation.
The recently adopted H.323 standard provides for video conferencing over IP-based packet-switched networks, such as campus computer data networks. Because H.323 is an accepted standard, hardware and software manufacturers are now creating products that adhere to the standard, which allows interoperability between systems from multiple vendors. The reliance on an international standard avoids the restrictions inherent in proprietary audio and video data formats and transmission schemes. The use of an IP network for transmission of the signal over an existing data network with sufficient bandwidth, rather than the creation of a separate ISDN network to campus classrooms and offices, can offer reduced complexity to campus network installations.
In addition to point-to-point connections, the H.323 standard supports multicast transmissions over the network, providing a non-proprietary solution for broadcast of video over the local area network with minimum bandwidth usage. Multicast allows a single video stream to be sent over the network to multiple recipients, eliminating the redundant bandwidth required by multiple point-to-point connections. Given a proper network configuration, H.323 begins to address both interactive video conferencing, network video broadcasts, and video on demand in a widely accepted standards-based environment. The H.323 standard also supports multipoint conferences, so that multiple participants can interact within an multiway video conference.
Many video conferencing equipment vendors are incorporating both H.320 and H.323 connectivity into their systems, allowing campus network administrators to connect these systems to whichever network is most appropriate currently, while retaining the ability to change to a different transport medium as circumstances dictate. This dual capability ensures that systems and equipment will be functional in the current and future network environment, thus relieving some of the concerns inherent in campus planning and acquisition. H.323 capability is being added to all systems across the product line, from desktop units through the large, high-bandwidth systems found in fully-equipped distance education classrooms. The variety of hardware solutions, coupled with the options of network connectivity, provide a rich set of choices for the technology classroom.
The bandwidth demands of H.323 video will place considerable strain on the campus data network. Considerable care and planning must precede the deployment of H.323 systems to ensure that the data network has sufficient bandwidth and is properly configured to support video streams of 128Kbps up to 768Kbps without degrading network performance, or perhaps compromising the entire network. Switched 10/100Mbps ethernet, ATM, or some other high-capacity network infrastructure is required to carry the large volume of continuous data involved in video transmission. In addition, network management software may be required to support Quality of Service (QoS) protocols, whereby some portion of the network bandwidth is allocated as needed for particular uses such as video conferencing. QoS networking protocols are required to ensure appropriate functionality for bandwidth-hungry applications such as video, while limiting the bandwidth allocation for the network as a whole to prevent degradation of current network services.
In general, the deployment of video conferencing systems will require an appropriate network to support the intended use. With H.320 systems, ISDN service must be provisioned to supply single BRI, multiple BRI, or fractional T1 bandwidth. Using H.323, the existing data network can be used, but only if it is properly configured to support the large bandwidth requirements of video streams. Depending on the campus network infrastructure, an institution might choose to provide an ISDN solution, H.323 IP solution, or a hybrid network to support current and future video conferencing systems. Without question, the increasing affordability of high-quality desktop and small classroom video conferencing systems will place additional pressures on network administration and development. It is critical that a campus strategy for network growth and support, whether ISDN or IP, be developed to support the inevitable growth of video conferencing and streaming video on demand.
A critical device in the deployment of H.323 video conferencing systems is the gateway. An H.323 gateway bridges H.320 and H.323 systems, performing the necessary transcoding between ISDN and IP transport networks, allowing communications between the two. A gateway performs two significant design functions: connecting existing H.320 systems to newer H.323 systems on campus, and bridging to the public switched telephone network (PSTN) for reliable wide area and long distance access to remote sites. It would not be a reasonable strategy to deploy H.323 video conferencing systems on campus if such actions make current H.320 systems immediately obsolete. The gateway device connects the two transport networks to provide full connectivity between ISDN and IP systems, thus ensuring that the investment in existing equipment remains functional.
Sufficient bandwidth for video conferencing over the Internet is seldom available. Consequently, video connections to the wide area network (WAN) typically do not ride over Internet connections but rather the classic switched circuit network available through the PSTN. The gateway device serves as a bridge to connect local area network (LAN) H.323 traffic to the robust carrying capacity of the public switched telephone network for long distance connectivity. A gateway at each end of a campus to campus connection converts the transmission from LAN H.323 to ISDN and back to the LAN. In addition, the gateway supports the connection from an H.323 device to a remote H.320 system, without user configuration.
An additional element in the H.323 standard is the gatekeeper. The H.323 gatekeeper registers all H.323 devices on the network, tracking IP addresses and assigned aliases for routing. Functionally, the gatekeeper resembles a domain name server, in that it is aware of the H.323 devices currently available on its segment of the network, and routes calls according to alias resolution, allowing a connection request to be formatted as "Tim'[email protected]" rather than a specific IP address. This address resolution makes the user's experience in initiating a video call relatively simple, with address books and meaningful naming conventions assisting the client.
Given that sufficient bandwidth for video conferencing is not generally available on a wide-area network that uses the Internet, H.323 systems will be most useful in the near future on the campus local area network, or perhaps the extended LAN running to remote locations via a virtual private network (VPN). Connections to off-campus sites will be served best through the ISDN public network, with bridging between the networks provided by an H.323 gateway device. A fully-functional campus video conferencing network might include several dedicated H.320 systems in well-equipped distance learning classrooms, numerous technology classrooms with desktop or small-classroom portable systems using H.323 compression and transport, and one or more gateway devices to bridge to existing H.320 multipoint conferencing units and to the public switched telephone network. It is easy to predict that hybrid networks will evolve to support the particular strengths of each of the two connection strategies, H.320 and H.323, while allowing full communications between the various devices. The advent of the Next Generation Internet (NGI), or Internet II, may relieve some of the bandwidth constraints of wide-area connectivity, but for now, switched circuit connections through the public telephone network will remain an essential part of a network design.
H.323 offers a method for expanding the number of campus video conferencing nodes on campus over the existing data network, provided that the network can sustain the projected bandwidth needs. Instead of running a separate ISDN network line for each system, the IP network infrastructure can be upgraded to provide high bandwidth to the desktop and through the campus backbone. Existing H.320/ISDN systems can still be used in conjunction with the H.323 transport network, and connectivity to the WAN can be seamlessly bridged.
The investment in desktop video conferencing systems in technology classrooms meets the traditional requirements of functionality, reproducibility, scalability, economic viability, and measurability. Desktop video conferencing systems are reliable, functional, and effective in both a technical and instructional sense. The H.320 and H.323 video conferencing standards assure interoperability with all modern teleconferencing systems, regardless of vendor. ISDN service provides high-quality connectivity with any CODEC or network connected to the public switched telephone network, and H.323 provides local area connectivity via the campus data network. The wider distribution of video conferencing capability at a reasonable cost allows for the incorporation of guest lecturers, collaborative discussion and learning projects, and, most importantly, experimentation with ad-hoc instructional contexts available through connections with content experts and students at peer institutions.
Most classroom computers will support appropriate video conferencing hardware and software, as complete ISDN packages are available for both Macintosh and Windows systems. Local telephone exchange carriers are expanding their ISDN offerings, and BRI connections are becoming increasingly common at reasonable rates. The quality and affordability of portable all-in-one video conferencing systems makes this type of product a meaningful alternative for adding interactive video connectivity into the classroom, whether on a permanent or as-needed basis. Given the existence of one or more technology classrooms or systems on campus, the addition of appropriate hardware, software, and connectivity should not be a daunting task, and can be duplicated within in a variety of technology infrastructures.
The installation of video conferencing capabilities to technology classrooms is scalable in both quantity and quality. Additional classroom connections should be available at a linear relationship between the number of systems and associated costs. Portable systems can be easily moved from room to room, and connected to the campus data network as requested. System enhancements of varying complexity can be added, depending on the need and cost, including multiple cameras, additional microphones for students and presenters, data and application collaboration, increased bandwidth, and integrated control systems.
Since technology and projection classrooms represent a significant institutional investment, the integration of video conferencing capabilities into existing facilities can be a persuasive alternative to the creation of custom video conferencing studios. The hardware and software to support video conferencing can be added to the existing classroom computer at reasonable cost, and an ISDN BRI connection to the public switched telephone network should be a manageable cost for both the monthly fee and long-distance connection charges. Portable systems can be integrated into the audio and video presentation system and connected to the campus LAN. The introduction of live video and audio into the technology classroom, allowing a wide variety of educational opportunities, will represent a significant enhancement to an already important campus resource.
The measurable outcomes from video conferencing capabilities in a projection classroom will be defined primarily by access to new instructional resources and the incorporation of those resources into existing and developing teaching methods. Guest lecturers can present to the class without the cost of transportation and housing. Students can interact with presenters, and with other students at peer institutions studying comparable material. Most importantly, the availability of video connections at affordable costs allow instructors and students to develop new models of interaction with a wide variety of resources.
Baylor University has engaged in some aspects of traditional video-based distance learning, providing graduate and undergraduate classes from the main Waco campus to the Baylor School of Nursing in Dallas and graduate students in educational administration in Conroe. However, faculty and staff have found that much of the value of video conferencing becomes apparent by incorporating interactive communication and collaboration into the classroom to enrich the educational experience. Frequently, guest lecturers have been able to make presentations and answer student questions by appearing in the classroom via video conferencing. The M.B.A. program at Baylor instituted a curriculum in which the entire cadre of students focused on a single corporation during the course of a semester, and monthly video conferences with that corporation's executives helped refine the students' presentation skills and provided feedback from the executives on the accuracy of the student research and analysis. The video systems have allow master's thesis defenses to include international faculty experts without incurring the cost of time and travel expenses. Baylor's student government has experimented with a series of peer to peer discussions with students at other institutions to share thoughts and experiences on the topics of diversity, drug abuse, and institutional differences. Finally, cooperation with area school districts, technical colleges, and museums has provided a surprisingly effective venue for unexpected collaboration and content delivery for ad-hoc projects. The critical success factors for the increased and imaginative use of the video conferencing network are its reliability, availability, and ease of connectivity. As the price of acquisition and support declines, coupled with increasing sophistication and functionality of desktop and classroom systems, the network will continue to expand into more classrooms to support greater breadth and frequency of use.
ISDN BRI desktop video systems and H.323 units will not replace high-end, multi-camera room CODEC systems. However, they do offer the opportunity to expand affordable connectivity into classrooms already designed for audio and video display. The integration of standards-based video conferencing tools into existing technology classrooms allows institutions to increase the use and flexibility of current facilities, while supporting a rich variety of new educational experiences through reasonably-priced telephone network connections. Widely distributed low-cost systems will encourage innovation and integration of live interactive video resources into the instructional process.
The equation involving instructional need, hardware costs, and network connectivity has changed dramatically in recent months. In addition to traditional distance learning initiatives, there are multiple techniques for incorporating live, interactive video into the classroom to enhance the students' learning experience, including guest lecturers, peer collaboration, and access to primary content providers. The cost of good quality video conferencing systems with sufficient flexibility and ease of use has dropped significantly, to a point comparable with document cameras and data projectors. Widespread availability of interactive video conferencing will encourage the imaginative and ad-hoc use of live video as an adjunct to the technology-rich instructional environment.
No longer does video conferencing need to be confined to a high-cost, dedicated
facility. By incorporating newly available and affordable systems into current
and planned computer-enhanced and projection classrooms via ISDN or data network
connections, new models for incorporating video-based resources into the instructional
process can be developed and tested within reasonable financial constraints.
The high-tech classroom can now be opened to the world of video conferencing
without breaking the bank.
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last modified, 11/2/98, Tim Logan