Confused by the myriad videoconferencing equipment on the market? Are you unsure if your school system’s network and computers can handle desktop videoconferencing? If you already know all the answers, then you must be an engineer for Cisco or VTELbut for the rest of us mortals, we’d like some simple explanations about the hardware for distance education, as well as other pitfalls that may be lurking to ensnare unwary schools.
First, an explanation of where we’ve been and where most of us are headed with distance education. Even the term “distance education” may be unfamilar to many, as the counterpart term “distance learning” has been far more popular for many years. Not to split hairs or quibble over semantics, but distance learning is actually the desired outcome or result of distance education. Distance education is defined as the process and techniques used to deliver instruction to a remote learner.
Historically, distance education involved correspondence study using land-mail deliveries of paperwork. Later, as local and cable television matured, learners could receive instruction over television broadcasts. Instructional audio cassettes and VCR tapes also became popular for many correspondence schools. But the biggest growth of distance education came with the explosion of the internet. Suddenly, instant 24-hour-a-day communication was available through eMail.
eMail, regular mail, and other forms of instruction that do not require the simultaneous participation of all students and instructors are called (jargon alert!) asynchronous instruction. These methods of distance education, in which the learners and instructors don’t connect in real time, have obvious advantages and disadvantages.
One advantage is that students may choose their own instructional time frame and gather learning materials as needed. If they want to work at midnight, their materials are still available. Another key advantage is the easy accessibility of asynchronous instructionanyone with a reliable internet connection can participate.
A big disadvantage of asynchronous instruction, however, is that students don’t have the ability to receive instant feedback. Instructors also may find that they are overwhelmed by the volume of eMail from students in their classes.
Synchronous education, in contrast, requires real-time participation of all students and instructors. While synchronous education provides students with instant feedback and is more interactive, the tradeoff is that it is also more expensive because it requires special hardware and software.
Until the past year, synchronous education has been achieved most commonly through dedicated circuit teleconferencing systems. The newest and most exciting entry into distance learning is packet-based teleconferencing, or teleconferencing achieved over IP (internet protocol)-based networks.
The new IP-based standard
The international hardware standard for packet-based videoconferencing is called H.323. It’s actually a recommendation by the ITU (International Telecommunciations Union), but one that carries the power of a standard. In layman’s terms, H.323 is a code of standards for videoconferencing over any IP-based network, such as the internet. H.323 can also refer to audio-only usage, but most deployments include video and data.
Before H.323 became available, there was H.320a videoconferencing standard for switched-circuit networks, issued by the CCIT (a predecessor itself to the ITU). Because the H.320 standard does not support the packet routing and addressing scheme of IP-based networks, though, deployment of H.320-based videoconferencing systems has to occur over a dedicated, direct connection between the end points via a high-speed digital line (such as ISDN).
In many ways, the two standards are similar: Both provide real-time, two-way communications with a device using the same standard. They also support the sharing of data using another standard, called T.120, although typically the H.320 systems require an additional outlet to a computer network to achieve data exchanges. They can even communicate between each other with gateway hardware products that enable H.323 applications to communicate with H.320 products. One common example of a gateway device that allows the two standards to communicate is Cisco’s MC3810 router.
In terms of abilities and hardware characteristics, however, the two standards are vastly different. The most obvious difference is the ease and cost of deployment. Because H.320 systems require a dedicated connection, they generally are more expensive to operate. In addition, H.320 systems usually are large hardware devices and are not as easy to move around a building.
By contrast, H.323 systems usually are smaller and can be moved to any existing Ethernet connection in a location. Also, H.323 systems typically are much cheaper to operate because there are no dedicated, leased-line charges to pay.
Because H.320 systems usually do not connect to a network server, they are limited to the system features found in the proprietary platform of the manufacturer. H.323 systems, on the other hand, are much more robust because of their ability to share applications over the network, and future applications likely will be developed to exploit this strength (examples: call routing, transfers, hold, and other features we use in modern telephone usage).
Although the new H.323-based equipment promises lower costs, it comes with its own unique set of challenges as well. Chief among them is assuring quality of service (QoS).
H.320 devices are hooked up to dedicated full-duplex digital lines that guarantee a specific amount of bandwidth bi-directionally. The internet-based local area networks (LANs) typically used by H.323 clients run on a half-duplex packet system, in which data are delivered in burst mode. Users on a network send commands to printers, move and copy files, download eMail, and also use videoconferencing equipment. It doesn’t matter if network congestion slows down printer and file operations by a few milliseconds; but for real-time video, that delay can spell a disaster for quality.
Solutions exist for the network bandwidth problem in H.323. One involves the use of gateways, such as the Cisco router mentioned previously, which contain management software to address the real-time needs of videoconferencing transmissions. Blocks of bandwidth can be set aside for use by H.323 workstations or ports.
Yet, if your network is already congested with internet traffic, you may find that H.323 conferencing can slow down other applications too much. In that case, you’re faced with the need to upgrade the amount of bandwidth to the network. This is a feasible solution, but it can get expensive.
Most H.323 systems recommend that you have a minimum bandwidth capacity of 1 megabit per second (Mbps) for each video stream in each direction. For a system that allows four simultaneous users to hold a conference, a minimum of 10 Mbps is recommended2 Mbps for each user, with enough bandwidth left over for data collaboration and call or session control. Since T1 lines provide only 1.5 Mbps of bandwidth, they just don’t have the bandwidth to support high-quality video transmissions.
“For all practical purposes, VHS-quality, 30-frames-per-second video over a T1 line is not doable,” said Bob Beaury, president and chief executive officer of Broadband Networks Inc. (BNI) of State College, Pa. “If you are willing to settle for lower-performance video, one or two two-way video connections over the link is all that you will be able to support. Plus, you will not be able to use the T1 service for much of anything else, except the one or two conferences taking place. The limited connections mean that the resource has to be scheduled, and there is no spontaneity in communications between buildings.”
If you’re not able to upgrade your network right away, Beaury said, the best way to leverage existing T1 service is to go with audio conferencing only and share data such as spreadsheets, slides, and documents.
Another issue to consider in using H.323 videoconferencing is the quality of your workstations. H.323 typically requires a minimum Pentium 166 MHz processor. Most computers built since 1998 will exceed that CPU speed, but older client workstations may fall below the recommended level for decent performance.
The performance issue, in part, will also be driven by the size of the videoconferencing image on the monitor (full-screen, or a very small window) and the frame speed required (televison quality is 30 frames per second, very slow is 5-10 frames per second). These are application requirements that users must examine carefully when looking at vendor offerings.
So, what’s the best choice for future distance education teleconferencing: H.320 or H.323? It’s a no-brainer…H.320 is a legacy protocol and a system that will die out over the next few years. “Smart technology planners can now safely regard H.320 as yesterday’s standard,” Beaury said.
Distance education purchases of H.323 systems will be in the millions of units and billions of dollars over the next three years, analysts predict. Another indication of where internet-based distance learning is headed is the fact that Microsoft has built support of the H.323 protocol into its Windows 98 and Windows 2000 operating systems.
Here are some things that network managers can begin to do to implement the coming explosion of H.323 videoconferencing:
• Upgrade older Ethernet wiring to Category 5
• Install switches on the LAN to maximize bandwidth capacity
• Upgrade routers to be H.323-compliant
• Upgrade Ethernet speed from 10 Mbps to 100 Mbps
• Upgrade workstations to faster CPUs
• Beef up leased backbone bandwidth, if possible
• Upgrade firewalls and proxy servers to be H.323-compliant
The basic infrastructure of any videoconferencing system is fairly simple: at least two end points, and a switching unit in the middle that regulates the video traffic between them.
The end points can be desktop computers equipped with hardware or software for the compression and decompression of video transmissions (be wary of software-only solutions for this), or they can be vendor-proprietary systems with add-on features such as projectors and large-screen monitors that make it possible for a large group to see the screen easily.
The type of end points you’ll need depends on how you plan to deploy the system and what type of video quality you hope to achieve. For broadcast-quality video, look for systems that offer a frame speed rate of 30 frames per second (fps). Another factor to consider is latency rate, which is the delay between when the signal is sent and when the image is received. True real-time latency (low enough as not to be perceptible to the human eyes and ears) is about 150-200 milliseconds (mS); practical systems can have a 400 mS latency and still provide decent conference interaction.
The day is not far off when most personal computers will have the capability to be high-quality videoconferencing end points, but for now, if you’re aiming for broadcast-quality video at a low latency rate, you might want to consider a proprietary end point from a videoconferencing solutions expert.
The type of monitor you’ll need is also driven by how you plan to deploy the system. The minimum image size for broadcast-quality video is 288 by 352 pixels, which means that if you plan to hold a videoconference with four users simultaneously, you’ll need a higher-resolution monitor than a standard 800 x 600 monitor.
Prices vary considerably on hardware, and your schools would be well-advised to examine new technologies carefully before committing to large-scale purchases. Consider the track record of the company, and ask for preview units to try before buying. It’s not a bad idea to get three or four products for preview and check them out for installation and ease of use.
The good news for schools is that vendors are recognizing that user-friendliness is a key requirement for videoconferencing systems.
“To be widely used, having a videoconference with someone should take no more effort or forethought than picking up a telephone and dialing,” Beaury said. “If you have to pick up the telephone to pre-arrange a video call, you aren’t likely to use the video. You’ll just do what you can on the telephone. Even worse, if you have to go to a special room to have a videoconference, you probably will hardly use it at all.”
Several vendors are taking advantage of the flexibility that videoconferencing over IP-based networks offers. They provide portable H.323 end points that can be wheeled into any classroom equipped with at least Category-5 (regular telephone) wire and can be plugged in for instant conferencing capability.
For instance, BNI offers such an option with its PowerPlay H.323-compliant system. Schools have a choice of 700 MHz Workstations, 900 MHz Rollabouts, or 1200 MHz ConferenceRoom set-ups that can all be plugged into any Cat-5 connection.
Every PowerPlay station includes interactive videoconferencing, video broadcast, and data collaboration capabilites. The systems also include far-end device control for remote sources, including video cameras (with the ability to pan, tilt, or zoom), VCRs, and DVDs (for remote playback of streaming multimedia). Document and application collaboration among all participants in a conference is available without the need for any third-party application.
One of PowerPlay’s exceptional abilities is being able to connect 4-6 participants in multipoint videoconferences without a multipoint control unit (MCU), which is a “video bridge” that typically connects multiple sites and can switch the video either automatically, depending on who is speaking, or manually, under the direction of a moderator. BNI has developed proprietary software that transfers the system’s intelligence to its endpoints and the network, so there is no need for a “traffic cop” in the middle.
PowerPlay’s innovative IPContact software supports H.261 and MPEG1 video coder/decoders with extremely low network latencies. All video streams are television-quality, full-motion 30 fps with 16-bit stereo quality audio.
“With BNI and PowerPlay, customers get a true end-to-end approach to their interactive multimedia conferencing needs,” Beaury said. “A detailed LAN audit is part of every serious PowerPlay system design to ensure that our network engineers provide hands-on help to condition any network for peak H.323 performance.”
One of the giants in the field of videoconferencing (the name is virtually synonymous with the technology) is VTEL. As the emphasis has shifted to teleconferencing and H.323 products, VTEL has shifted production lines to meet the new demand.
According to Russ Colbert, senior director of education, the great discriminator between products will be the quality factor of not only the hardware, but also the applications that run the products. VTEL has a new line of stand-alone H.323 systems, called Galaxy, that is proving to be a top seller. Recently, Region 10 Education Service Center in Richardson, Texas, bought 39 of the Galaxy systems for use in local schools.
Oklahoma schools also will be trying the new VTEL units by connecting eight rural schools in a three-county area in the Oklahoma Panhandle and using live, two-way video and multimedia applications over the cooperative’s new H.323 network. The entire deployment will include more than 50 Galaxy Model 755 systems. The contract was part of an $8 million grant program for video and internet distance learning funded by the Oklahoma State Legislature.
“With the ability to collaborate, share work, and interact in real time with other students, Galaxy’s features make it the right product to help the students in rural western Oklahoma extend their access to important learning resources,” said Steven Keilen, VTEL chief marketing officer. “Galaxy’s easy-to-use interface and unique Vtouch remote control unit enable both teachers and students to quickly master the system and incorporate videoconferencing into their daily activities.”
A newcomer to the distance education market is Polycom Inc. This California company sells a large line of H.323 products that are extremely simple to operate. There is a wide variety of choices in the ViewStation line, and teachers will appreciate the easy-to-use hand control.
The ViewStation FX model contains an embedded four-port MCU to easily call as many as four sites in full-motion 30 fps video for a continuously present videoconference call. Voice-activated switching, chair control, and one-button address book dialing make ViewStation FX a powerful and easy-to-use meeting tool. The nice thing about rollabout, stand-alone systems like the ViewStation and units from other competitors is that the boot-up time is so fast (11 seconds). Also, users don’t have a computer that can be disabled by operator mistakes or ill-behaved third-party applications.
High-end teleconferencing users will be interested in the new rack-mounted ViewStation 4000. It comes with an embedded 10/100 Ethernet hub and conferencing flexibility for H.320 and H.323 calls. Embedded web capabilities and remote management allow network managers to perform diagnostics and software upgrades. The VS4000 includes easy, on-demand multipoint conferencing for up to four sites at 384 Kbps with continuous presence.
Another long-time videoconferencing company, PictureTel Corp., recently became the worldwide distributor of the Intel ProShare Video System 500. The Proshare system is an ISDN/LAN solution interface card and color camera that installs on the user’s PC system. The popular and inexpensive Proshare model has been a big hit for several years. One thing that had limited earlier sales of the Proshare card was the need for a fairly fast CPU and generous amounts of RAM. Now, many inexpensive machines have the horsepower to properly use the Proshare system.
If you are buying this model, along with a new system, try to get as much horsepower as possible for your PC. Region 14 Education Service Center in Abilene recently installed 43 Proshare systems in new Dell computers through an administrative computer grant. The computers came with 500 MHz CPUs and 256 MB of RAM, quite enough power to run the videoconferencing software and achieve good video display with the cameras.
FVC.COM, a major vendor of broadband video networking products, designs, manufactures, and supports a wide family of products for real-time interactive video, streamed video, and broadband access. FVC has specialized in network hardware and services instead of the endpoint teleconferencing devices. One of the company’s unique server products is the the V-Gate 4000, which is the industry’s most flexible bridge between the traditional world of ISDN (H.320), ATM (H.321), and the emerging IP (H.323) videoconferencing standards. To bring these standards together, the V-Gate 4000 delivers full interoperability between IP, ATM, and ISDN-attached end pointsextending videoconferencing from high-end room systems to low-end desktops and everything in between.
Another product that FVC is working on is a video portal interface. One of the big problems in teleconferencing is the interoperability issue. VTEL users trying to talk to Polycom users experience different user interfaces on each end. The FVC interface allows for a common software interface on the browser (Netscape or Internet Explorer) and makes the process much more user-friendly. “The future of successful teleconferencing will depend on making the interface as easy as eMail,” says Elyse Phillips, director of corporate communications for FVC.COM.
An educational movement that’s beginning to spread like wildfire across the globe is the idea of the “virtual classroom”a classroom based on eMail correspondence, without any geographical barriers. Students learn from instructors thousands of miles away and set their own time schedules for completing assignments. Virtual classrooms are beginning to shake the sacred columns of traditional schoolhouses, as educators and administrators begin to realize there is more to the internet than just a huge research database.
The new virtual schools are drawing pupils ranging from the heavily populated urban districts in Florida, which are straining to find room for regular students, to the sparsely populated rural districts in the Oklahoma Panhandle, which don’t have the staff to provide a full offering of courses. Their reasons for employing distance education may be different, but each district is pursuing quality distance learning as its end result.
One of the first public school programs to offer high school courses for credit over the internet was Eugene, Ore.-based program, Cyberschool. This virtual high school consortium, which offers 44 asynchronous classes available to any high school student around the world, operates on a concept of distance education that “the greater the reach, the more powerful the learning. A high school class about World War II is exponentially different from a normal class, says Cyberschool creator Tom Layton, if the students live in Nagasaki, Berlin, Rome, Moscow, and Pearl Harbor.”
According to Layton, the biggest challenge facing virtual instructors is how to use the technology to the best effect: “The question is not whether you have chat as a part of your course. The question is, how can you use chat to best engage the students in the learning process?”
For virtual learners, the challenge lies in adapting to a system of learning that is completely new to themincluding the added responsibility that comes with being freed from the structure of a typical school day.
“Students have a hundred years’ worth of ancestors who know what school is supposed to be like,” Layton said. “At 8:00, you go to English, take notes, take tests, do what the teacher tells you to do, wait for the 8:50 bell, then go to math and do the same thing. But most students don’t even know anyone who has taken a class online.
“Two of our students said it best: ‘The best thing about Cyberschool is that there isn’t anyone standing over your shoulder telling you what to do. The worst the thing about Cyberschool is that there isn’t anyone standing over your shoulder telling you what to do.'”
Basehor-Linwood School District, a school district of 2,000 students in Kansas, has implemented the first virtual school for the entire state of Kansas. Currently enrolling more than 300 students in a Virtual Charter School, the district is doing very innovative things with teleconferencing and incorporating technology across the curriculum. Its goal: provide an education to all types of students, even the ones who would rather stay home.
Every teacher has his or her own web page and communciates virtually, even with students in the regular classroom. The Virtual Charter School home-based instruction provides an iMac computer inside each student’s home and employs a password-protected web site for instruction, homework, and collaboration with staff and other students. The home-based students (95 percent of whom are homeschoolers) use chat rooms via the internet for real-time interaction with staff and students and enjoy enrichment materials, activities, and virtual field trips.
“We have an exceptional relationship with our charter school students,” said David Pendleton, superintendent of the district. He reports that students who work at home have tremendous motivation from their homeschooling moms, who act as facilitators for the coursework.
“Homeschoolers have chosen to learn at home for a wide variety of reasons, including the commonly mentioned school safety and religious reasons,” said Pendleton. “However, we find a lot have chosen that option because they just learn better in a non-traditional settingand web-based training is a great tool for allowing them access to modern public education.”
The charter school students are accountable through testing instruments and a face-to-face, end-of-year exam (which is an evaluation strategy also used in the Florida High School, another virtual learning environment for Florida students). The state of Kansas provides full state funding for each student in the charter school, payable to the school district. Basehor-Linwood has developed a full corps of cyber-teachers to handle the web-based instruction.
A need for special training
When two Indiana University, Bloomington, researchers released a case study in September that exposed some of the problems of distance education, critics of the study were quick to argue that the problems in this particular case were likely to be the result of the individual teacher, not the concept of distance education itself. Still, the experience of the teacher and students in that class highlights the importance of proper training for teachers who teach in an online environment.
Teachers “have to be comfortable in the online environment. They need to have regular, dependable access to technology and support when problems arise,” said Terry Gray, director of a new virtual school for educators, Connected University.
Created by the folks at Classroom Connect, Connected University provides a wide range of technology staff development for teachers. A low yearly fee allows subscribers to take any of the offerings. Most courses are short, six-week modules with a set beginning and ending date. Some of the typical courses include Getting Started on the Internet, Teaching to Standards, and Technology and Assessment.
The cyber instructors at Connected University are some of the top educational technologists in the world. They received special virtual training from Pepperdine University, one of the nation’s leading universities in educational technology degree programs at the master’s and doctoral levels. Pepperdine faculty also review the course content of each class.
The need for virtual educators to receive special training is important, Gray said, because communication is more than simply the words we say or write: “We know that the best teachers are most often those who are highly responsive to the needs of their learners. For [online teachers] to be effective, they have to develop new ways of sensing the needs of their learners.
“For example, in a face-to-face setting, teachers can rely on sight and sound. They know when a concept is understood, or when students are ‘getting it,’ by their facial expressions. They can tell when students are working well together on projects by the hum of classroom conversation.”
“Guides,” or online instructors, at Connected University are required to take a Guide Course before becoming a teacher for the university. Much of the course focuses on supporting learners’ dialogue in the online forum, Gray said. Guides learn that they can tell how their learners are doing by relying on a new set of visual cues. For example, clusters of messages grouped around a single question or topic demand immediate attention.
“Like ants around a sugar cube, a cluster can mean the class is excited about a wonderful finda great idea, a compelling example, or a stimulating question,” she said. “On the other hand, it might be more like a flock of vultures descending on carrionlearners might be upset, they might be attacking and defending something someone said.”
Guides are also encouraged to take note of the length of someone’s messageanother new visual cue: “Newcomers to an online discussion are sometimes tentative; their messages are brief and shy. They need to be coaxed into elaborating. As their comfort grows, so does the length and depth of their responses.”
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