Designing a Webcasting Facility

Over the past three years, Digital System Technology has expandedbeyond its traditional niche as a broadcast systems integrator andplunged into the world of webcast systems integration. It’s achange we’ve been able to adopt rather easily, but we’velearned along the way that webcast systems integration is not a carboncopy of integration in the broadcast industry. While there are plentyof similarities, there are also many differences that must beunderstood thoroughly when setting up a webcasting facility.

First of all, there is the difference in the knowledge-base of thepeople involved in each of the different markets. Broadcasters, forexample, have a familiarity with the environment required to build atechnical facility and have an understanding of electrical and HVACissues. Webcasters do not. Nor do webcasters have much experience inbroadcasting. On the other hand, most broadcasters have minimalexperience encoding multiple streams of content. In contrast,today’s webcast facilities can record anywhere from 10 to 500simultaneous streams.

The planning stages in a webcast facility construction project arecrucial to make sure everyone is headed in the right direction. To geta facility off to a good start, it’s critical to clearly definewhere a webcaster’s business is today and where it wants to go inthe future, based upon the company’s business plan. Over the pasttwo years, we’ve seen some very aggressive projections.Unfortunately, not many of these projections have been met. As asystems integrator, it’s our job to be a bit more conservativeand challenge the underlying beliefs of the business model, whilesimultaneously planning and building a facility that can both meet andensure future growth.

Ultimately, it all comes down to economics. A webcaster has toconsider the cost of the individual path or stream. They must carefulevaluate how much equipment can be dedicated to processing a singlestream of information. A broadcaster may transmit one stream ofinformation, while a webcaster may transmit 250 simultaneous streams.When selecting equipment for a webcast facility, you have to becreative and conservative in how much you spend on hardware for eachpath of information processing.

Webcast facilities generally use equipment identical to a broadcastfacility up to the point where the data hits the encoder. Webcastersalso often use traditional routing switchers, video processors, andconversion equipment. For example, DST recently provided systemsintegration for NaviSite.com, a 10,000-square-foot facility that hasbeen the host for many recent high-profile webcasting projects,including the Mir Space Station Re-entry and “Wango Tango,”a two-day concert at Dodgers Stadium featuring The Bee Gees, ChristinaAguilera and Aerosmith. NaviSite uses traditional A/V routing equipmentto route standard analog signals to a digital capture machine where thesignal is encoded in Real, Windows Media and Quicktime formats prior todistribution.

Webcasters often use unique routing equipment for monitoring androuting video streams to multiple encoders from a single destination.Because webcasters are dealing with so many streams, facilities such asNaviSite need solutions to monitor each encoding process from a singlelocation. The process is simplified through the use of a centrallocation for stream monitoring using a keyboard, mouse and PC.

Webcasting is unique in that test and measurement takes placefollowing encoding. In contrast, in a broadcast facility, allmeasurements, signal testing, and confirmation of quality takes placebefore the video stream hits the transmitter. In webcasting, thosemeasurements are analyzed after the stream has been sent through theencoder.

Differences are also found in the area of noise reduction. Inwebcasting, you actually want to make the signal look worse because youwant to lower the bit rate. Encoding unnecessary high-chroma,high-luminance-based signals is undesirable. Unlike the broadcaster whoneeds the picture as sharp as possible for transmission, the webcasterwants the picture flatter, so the encoder can work with a lower bitrate.

As a systems integrator, it becomes our job to educate the customer.When we work with webcasters, we are essentially educating them aboutbroadcast techniques. Most have a solid understanding of the encodingprocess: they understand how to send a signal through the encoder anddeal with the reduction of bit-rates. Once the signal hits the encoder,everything from that point on involves the touch of a mouse. Inbroadcasting, it’s more of a manual process because you’redealing with a baseband signal that must be processed correctly.

Understanding how to acquire the signal, process it, and automatethe function to get the signal to the encoder is the greater part ofwebcasting. For system integrators, the trick is to make the signalsflow to the encoders and provide the automated turnkey encodingsolutions developed specifically for webcasting .

Therefore, automation is more sophisticated in webcasting and it isessential to ensure efficiency. Because you’re dealing withmultiple streams, many more devices are being controlled than is thecase in a broadcasting facility. Traffic and scheduling systems need tobe much more complex. For example, Real Broadcast Network (RBN), whomwe assisted in the construction of an all-digital Internet broadcastoperations center (IBOC), broadcasts 3000 streams per day. Theautomated process in this facility is what makes RBN so efficient. As aresult, operations are streamlined, workstations are improved, and eachoperator has complete control of all RBN operations from his or herdesktop.

Perhaps the most substantial difference between the two types offacilities is in the area of future expansion. Growth in broadcastingis certainly more predictable than in webcasting, where explosivegrowth can happen at a moment’s notice. Traditionally, there is a30 percent growth factor figured into the construction of a newbroadcast facility. In webcasting, the growth factor considered ininitial implementation often approaches 300 percent. Obviously,planning ahead of time for facility infrastructure growth is a must. Todo that properly, you have to consider everything, particularly realestate, HVAC, electrical issues, router upgrades, and satelliteexpansion.

The key in designing both types of facilities is to plan for thegreatest projection, build for current needs, and set milestones forgrowth so you can forecast the upgrade. With a webcast facility, itcomes down to the design of one path. Everything in a webcast facilitygoes through the same path. So whether the streamed content is createdoriginally within the facility, taken from pre-recorded material, orfrom a satellite, everything goes through the same path before hittingthe encoder. This is a much simpler process than in a broadcastfacility. In a webcast facility, you simply multiply the initial path.This means you can pre-wire a facility for growth and easily add thosedevices to the path when needed.

The most pertinent components for expansion are always related topatching and routing. A router must have the flexibility, overhead, andreal estate to integrate the equipment necessary for expansion. Thatmakes the planning of rack space very important. In a streamingfacility destined for growth, it’s absolutely vital to leave asizeable amount of empty rack space to accommodate expansion in ahurry.

Broadcast facilities, historically, aren’t blessed with atremendous amount of real estate, which makes growth more difficult. Inaddition, they have much larger operating systems. In webcasting,everything is controlled from a PC, so moving dedicated control panelsand monitoring devices around is not an issue. Expansion needs to besimpler in webcasting because of the potential for explosivegrowth.

Interestingly, as technology has developed to accommodate thisunique need of webcasting facilities, broadcasting facilities havebenefited from the introduction of better and more efficient controlsystems.

Mark Siegel is vice president of business development/partner atDigital System Technology.