new networking technology: offsetting the cost of upgrading

The digital television firestorm that we envisioned several years ago has so far provided little heat and less light. Nevertheless, we live in an extraordinary time in relation to the future of television broadcasting as we know it.

With the transition to digital television (DTV) well into its third year, you are probably facing both great opportunities and equally great uncertainty, depending upon your deadline for implementation.

Issues fueling change Government regulatory and political requirements, advances and limits in technology, and existing and emerging business opportunities all provide fuel for the fire. How the sparks fly in your areas of interest, where they land and how well they can be controlled will determine your DTV future.

Implementation of DTV is fraught with political and technological issues.

At this time, COFDM modulation has failed the FCC litmus test and is before the U.S. Congress for review. Depending on your viewpoint, this issue may or may not play a profound role in our future. For those few who are not familiar with this topic, the issue is COFDM vs. 8VSB in multipath reception. In this case, the real and more important issue may prove to be COFDM vs. 8VSB in mobile reception.

Business issues So far, the transition to DTV has been slow, with approximately 150 out of over 1600 television stations nationwide having upgraded. It appears that finding and making a business case has been the biggest obstacle to the transition. A quick analysis reveals that, depending upon which markets they serve, typical television broadcast facilities need to budget anywhere from $2 million to $5 million to upgrade to DTV. This includes obtaining construction permits and installing towers, as well as new transmission equipment. Not included is the cost of upgrading equipment within the plant, such as routers, servers, switchers, etc.

Because most facilities derive their income from the transmission of commercials, the question asked most often is, "How many more viewers will my DTV signal attract?" The answer is none, as the population demographics will remain largely the same. Therefore, typical broadcasters will have to bear the cost of upgrading to DTV, without the benefit of additional revenue to offset the expense.

In order to mitigate the cost of upgrading, some broadcasters are looking at other business opportunities beyond traditional broadcasting.

One is datacasting, in which unused portions of the transmission spectrum are filled with data, typically Internet Protocol (IP) data, which can be extracted at the other end using an Integrated Receiver-Decoder (IRD). It makes a lot of sense for a television broadcast facility to use its surplus bandwidth for data, especially when that data can be distributed at relatively high bit rates. For example, a standard-definition transmission could have enough room to add upwards of 15Mb/s, whereas high-definition transmission has room for upwards of 6Mb/s. Initially, this type of datacasting would be targeted at corporations for business-to-business applications. Later, as applications and bandwidth requirements become more developed, datacasting can be expected to migrate into the consumer market.

By implementing conditional access, data could be transmitted that would only be decodable by authorized entities. This enables content to be distributed from a single point to multiple points, securely and efficiently. New entities have sprung up to take commercial advantage of this capability.

New equipment manufacturers have also developed innovative hardware that allows data to be dynamically injected into a transport stream. In this example, an unused packet, also known as a null packet, is replaced with one carrying data. By monitoring the incoming signal, the amount of data injected into the stream can be controlled to prevent system overload.

While datacasting has taken off in the satellite transmission business, it remains to be proven as a viable business for broadcasters.

Another way to help offset the cost of conversion to DTV is centralcasting, where a group owner consolidates two or more facilities into one. Having one facility broadcast several channels through multiple station-to-transmitter links reduces expenses considerably and thus offsets much of the DTV upgrade cost.

Avenues for distribution Today the majority of viewers, more than 65 percent, receive their broadcast television signal through cable. The remainder is split between over-the-air and direct-to-home, with a miniscule number receiving their signal through a telecommunications service. The telecommunications services are the ones to watch.

The differences between video data and other data are fast becoming indiscernible. The only difference is that in order for video data to be viewed, its time-sensitive requirements must be met. It should be noted that data pipes are expanding so quickly that video data can be transported faster than real time. This means that while the signal is being cached, it can simultaneously be viewed.

Telecommunications companies have begun to run fiber-to-the-curb (FTTC). In some areas this was completed over a year ago. This can have profound implications for consumers, especially when combined with dense wave division multiplexing (DWDM). DWDM is the process of passing laser light at different wavelengths through a single strand of glass fiber. Each adjoining wavelength may be shifted by as little as five nanometers from the next, and each can operate independently and transparently from others.

Currently, each wavelength may carry signals at rates up to 10Gb/s - one billion per second (OC-192).

Today, network switches and add-drop multiplexers running 160 wavelengths are being deployed in some network cores at 1.6Tb/s (one trillion per second) within a single strand of fiber. As this technology migrates to the curb, it will become possible to deliver more and more bandwidth to the end user. In fact, in Sweden, 155Mb/s (OC-3) is already being delivered to consumers. Furthermore, the present number of 160 wavelengths is only a starting point. Industry experts anticipate that it will be possible to run up to 1000 wavelengths in a similar fashion within a few years. At that rate, the bandwidth within a single strand of fiber will be simply mind-boggling.

Besides the exponential growth in bandwidth (also known as broadband), Internet Protocol management techniques will play a greater role in signal distribution. Protocol wrappers such as real-time transport protocol (RTP) and real-time control protocol (RTCP) are used to prioritize and transfer media in real time while real-time streaming protocol (RTSP) makes it possible to send that data using a streaming method. Streaming simply means that the whole file does not have to be transferred before it can be read, as is the case with file transfer protocol (FTP).

In the future, these special protocol wrappers will be used extensively to identify the type of data packets and how they should be processed. For example, if the wrappers contain time-sensitive television and radio signals, they will be handled with a different priority than simple data files, such as bank statements and other documents that are less time sensitive.

Each new Internet appliance will automatically recognize the data's coded signaling and process the data accordingly. The PC will remain the ubiquitous device that, when equipped with the right applications software, will allow the data to be processed appropriately.

The advent of broadband availability, combined with protocol management, will totally change the nature of the broadcast business. Broadcasting will simply become one of many mechanisms to deliver data and will probably play a greater role in mobile wireless applications. For fixed site situations there will be a choice of vendors supplying the service. It is expected that telecommunications companies will be dominant players, while cable companies will play secondary roles in signal distribution.

Looking forward ten years, I expect to see the business case and market conditions being the driving factor, especially when new technology becomes available.

Broadband and the Internet appliance will be passe, and consumers will be able to select any programming at any hour, thereby freeing themselves from network schedules and time slots. The granularity of advertising will be down to the individual household, and advertisers will be able to select the specific demographics.

But, no matter which way government requirements go, regardless of any advances or limits in technology we experience, and despite the business requirements of broadcasters and telecommunications companies, one thing is certain: Ten years from now, content will - as always - be king.