By Pat Cassella, President, ETCVideo and Will Bakewell, President, Visionary Solutions Inc.
Video in today’s classroom can take on many forms and can fulfill multiple application needs ranging from CATV distribution to local classroom capture. In years past, video distribution involved the use of analog delivery equipment that required a separate (coax) network with dedicated runs to every classroom. This was a costly solution requiring multiple pieces of equipment to deliver isolated video content and applications. Fast-forward to the modern classroom and we find that advanced technologies in the world of IPTV has changed how video systems are engineered. This paper will outline the converged benefits that IPTV systems deliver to the classroom along with the cost efficiency they provide.
A quick look into today’s modern classroom shows that something is noticeably missing – coax cable runs and expensive analog matrix switches to create an isolated, dedicated video network. Traditionally, schools were wired to support three separate networks – the phone system, data (computer) network, and analog video distribution (usually TV). However, in today’s converged world, the video being delivered to the classroom is riding on the same network that connects the school’s computers and is also used to surf the Web. While this IPTV migration has been happening gradually for the past 10 years or so, it is becoming increasingly more commonplace in our schools as the network equipment to deliver IPTV becomes more advanced, integrated, and affordable.
As the applications for IPTV continue to grow, one of the most commonly requested classroom needs is to simply bring TV into the classroom to show news, documentaries, and current events to the students. Television channels like Discovery, History, PBS and others offer rich curriculum that can be a valuable teaching tool in the classroom.
The delivery of TV to the classroom over IP starts at the building demarcation point – the location where the cable, satellite, or DSL feed brings television signals into the building. These modulated signals are fed into a demodulation system such as a Blondertongue or to a TV provider’s tuner which is used to select a particular TV channel and create an output signal that can be displayed on a monitor or TV – however few people watch TV in an equipment closet! In order to move the TV output to the classroom through the use of IPTV, the signal is fed into an encoder. The encoder connects to the Local Area Network (LAN), digitizes/compresses the audio/video input (usually HD through HDMI or SD through component or s-video), and turns it into an IP routable audio/video stream.
Encoders used for TV distribution are typically high-density (multiple-slot chassis), rack-mount systems that accept 12 or more IP encoder blades and can deliver simultaneous IPTV channels. Since there is a one to one relationship between the number of TV channels and IP encoders, schools will usually pick the most popular channels to be delivered as a way to keep the equipment costs reasonable.
More often than not, the IPTV streams that carry TV distribution are carried on the IP network through a delivery method called multicast. This form of delivery has significant bandwidth advantages over unicast-based delivery: regardless of the number of viewers, a multicast stream uses just a single stream worth of bandwidth. This is especially useful when distributing the TV channels across multiple schools in a district over a Wide Area Network (WAN). By comparison, a unicast stream would equate to a single stream of bandwidth to every user currently viewing the TV channel, thus greatly increasing the amount of bandwidth required. The cost savings of IPTV delivery can be significant in the case of school districts that are connected over a WAN if one considers the investment necessary to equip every school with an independent analog coax video distribution system. With an IPTV delivery system, a single video headend can deliver audio/video to an unlimited number of connected schools which is a significant cost savings over a coax based system.
Classroom capture and playback
Back in the classroom, a teacher can easily access the TV stream by navigating a program guide of available channels (much like a home TV system) through a web browser using a classroom computer connected to a projector. This program guide is typically created by a video distribution device called a portal server, which is a combination of hardware and middleware that manages and controls the entire IPTV system. By selecting the appropriate channel from the program guide, an IPTV stream is delivered to the classroom computer and rendered in a media player such as Apple® QuickTime, Windows Media®, Adobe® Flash®, VLC Media Player, or any other custom player.
But what if a teacher wants to record the channel? Today’s media distribution systems also include a video recording feature much like a DVR works in a home TV receiver – a simple pressing of a button in the system control portal records the TV channel being watched automatically onto the system. This is accomplished by capturing the streaming packets on the IP network and saving them to a file. Compared to the old TV and VCR cart, this greatly simplifies the process of capturing video content. Teachers can then share the content with other teachers and classrooms, re-use it in a future class, or develop course curriculums.
For those schools with subscriptions to content, such as that provided by Discovery Education, the delivery system can integrate with a pre-loaded content engine (on-demand server) which contains all digital assets on a pre-loaded hard drive. Streaming this content locally from the LAN can be especially useful in eliminating traditional content downloads from the Internet, improving content quality and avoiding clogging up the Internet connection during classroom hours.
Content consumption is not limited to the classroom – systems can also be designed to deliver all live feeds and on-demand content as RSS feeds or video streams over the Internet. A server is often used for flash transcoding so that the content can be displayed on ordinary home systems as well as smart phones, tablets, and other PDAs.
One can quickly see how an IPTV delivery not only replaces the need for a dedicated video coaxial network, it also eliminates the need for a TV and VCR in every classroom while providing an integrated platform for video streaming, capture, and playback.
Principal’s morning announcements
Why use an old audio public announcement system when a picture is a worth a thousand words? School principals and administrators can use the same IPTV system to effectively communicate through a video broadcast with every classroom simultaneously. When it comes to creating a morning announcement, most IPTV distribution systems use a portable, single channel IPTV encoder rather than the rack-based system that is used for TV distribution. This encoder is generally mounted either in a portable carry case or on a mobile cart that can be easily wheeled into a room for creating a live broadcast.
As opposed to TV distribution where a demodulation device is used, the announcement system uses a camera and microphone connected directly to the encoder which again, digitizes, compresses, and delivers the audio/video stream where it can be picked up and decoded anywhere on the IP network such as classrooms, auditoriums, and entrance ways. This allows a quick and easy way to address a classroom, an entire school, or even the school district without ever having to leave the classroom.
Most students are more engaged in a topic when they are actively participating – and what better way to learn about current events than to broadcast them to your teachers and fellow students? The technology used in this application is identical to that of the principal’s morning announcements and in some cases an actual dedicated IPTV broadcast studio is constructed, complete with green screens and special effects. Teachers can provide homework assignments to students to find a current event to discuss the next day as part of the student news channel. This is then broadcast (multicast) to every classroom to create an in-house news network. Many schools often have classes take turns creating the news casts, recording them and holding a contest later in the year to give a series of awards (most informative, best presentation, etc.). This engages the students and gives them an opportunity to help to teach one another, while improving their memory and speech skills.
Special event webcasts
Special event webcasts such as sporting, class plays, graduations, and awards often involve off-LAN streaming to recipients that are outside of the school’s network. This type of IPTV event most often requires the Internet in order to deliver the broadcast and is typically called webcasting. The technology used to stream special events resembles that of the principal’s announcements which involves an encoder with a camera and audio equipment. However, the connection to the remote audience is most commonly through the Internet. In the case of Internet involvement, multicast is not an option. Therefore, each stream must be unicast to a specific viewer, thus requiring either an adequate unicast bandwidth from the source site or a way of taking a single stream and distributing it to multiple viewers. The latter is accomplished through a technique called “stream reflecting” which uses a content distribution network partner such as Akamai, Limelight, or Internap to deliver the stream to the target audience. When webcasting, considerations must be given to the equipment selection with respect to stream format type to determine what is supported by the content delivery network.
Digital asset conversion
Most schools either have an old VCR tape collection or a library of DVDs for use by teachers and students. In either case these are physical assets that must be cataloged, distributed to users, and managed properly. Physical assets run the risk of easily becoming damaged or lost. Further, showing an asset in a classroom requires prior planning involving requesting and obtaining of the asset in advance of the class in addition to the playback device. But, in the world of digital asset distribution, assets are encoded using an IPTV encoder and then saved on a device called a video-on-demand server where they become shared assets, ready to be viewed on-demand anytime, anywhere. When these assets are added to the distribution system, associated metadata (title, author, subject, keywords, etc) is created to make them easily searchable by the teacher. This creates a sense of learning spontaneity in the classroom that is otherwise unachievable with a physical asset based system. This digital delivery system greatly simplifies the management process by eliminating physical asset management and the associated delivery service, thus freeing up valuable media specialists to work on other tasks.
The uses for IPTV in the classroom are growing daily and the benefits are numerous. Encoding technology is becoming more advanced and integrated with full turn-key systems available from multiple manufacturers. With the widespread adaptation of the H.264 standard for both SD and HD, the costs are declining, bandwidth requirements shrinking, and stream quality is improving.
Beyond the benefits associated with opening up applications that can help to foster and improve education, the costs savings of operating a converged IPTV network can be significant. IPTV in the classroom provides learning opportunities, new curriculum methodologies, and operating efficiencies that continue to help improve education across the United States and abroad.