In order to store large amounts of diverse information, a disc with a large capacity is essential. DVD achieves this capacity by reducing the track spacing to about half that of a CD, making the pits smaller and the spiral tighter, and by recording the data in as many as four layers, two on each side of the disc. In order to read the data, a laser with the ability to read in much finer detail is required. While the laser in an ordinary CD-ROM drive has a 780-nanometer (nm) wavelength, DVD drives use lasers with 650-nm or 635-nm wavelengths, thereby supporting more than double the pits per track, and more than double the tracks per recording surface. Other advances, such as a new sector format, better error-correction code, and improved channel modulation, raise the data density an additional one and a half times. By focusing the laser light through a larger aperture lens, a narrower focus is obtained and high-density reading is achieved.
A DVD disc is comprised of two 0.6 mm thick discs bonded back to back, which not only helps strengthen the disc but gives it the same 1.2 mm thickness as a CD. This bonded configuration also makes these discs less prone to warping due to heat and humidity compared to the single CD disc. Most DVD discs can store 4.7 GB of data on each side, or 9.4 GB total. However, there is a technique for increasing density that will soon result in discs that can hold up to 17 GB of data, the equivalent of 26 normal CD-ROMS. This technique, adding another data layer, would double the capacity of a single side. By making the first layer semi-transparent, a second laser could actually punch through and read the data on the layer beneath. This technique sacrifices a little capacity per side, down to 8.5 GB, but by bonding these two dual-layer sides together, a 17 GB capacity is achieved. Also, through this ability to store data much more tightly, DVD drives throughput can exceed that of a 9x CD-ROM drive, and can transfer data up to 2.7MB per second.
One other aspect of DVD technology that is worth mentioning is the development of special recordable discs. Their are two types of recordable discs available: DVD-R, with a capacity of 3.95GB and the ability for one-time recording, and DVD-RAM, with a capacity of 2.58GB and the ability to write over and over, both of which hold less than the 4.7GB capacity of read-only discs. Analysts predict that it will be late 1999 before 4.7 GB will be available on one surface of a DVD-RAM disc.
With regard to video, DVD discs can be manufactured for one-fourth the cost of a VHS tape and are much more durable. DVD also has the potential to deliver studio-quality video that’s even crisper and more colorful than that of a laserdisc, with 25 or 30 frames per second full-screen video resolution, multiple data streams for closed captioning and dubbing in multiple languages, virtual reality and high-resolution graphics with text and video support, and parallel video streams for viewing from different angles. DVD’s audio benefits may be best of all, delivering digital surround sound, including Dolby AC-3, which supports six separate channels of high-quality audio. Some experts are even predicting that DVD will be to VHS what the CD was to the long-playing record.
Consider a college recruiting office and the information they distribute to all prospective students. Class catalogs, videos of the campus, applications, interactive software, etc. are all becoming common materials distributed by admissions offices at most college campus’. It would be very beneficial to be able to distribute one DVD which contained all of this information on a single disk. This could reduce costs for production of the materials on the other mediums as well as distribution costs for mailing these larger, heavier packages. Clearly there are still costs involved in the production and distribution of a promotional package containing a single DVD, but if this expense became sufficiently cost-effective, the option of delivering their material in this manner would be an interesting alternative.
It is possible to imagine other similar scenarios where an organization
has to deliver large volumes of information to their “customers”.
The CD-ROM replaced many former ways of distributing large amounts of data
and it is possible for the DVD to perform the same task in an era of ever
increasing data volumes.
But after the CD impacted the music industry, it impacted the computer industry. So, what about telecommunications? What will DVD do to our use of computers and networks in the future?
As described in the “Review of Technology” portion of this proposal, DVDs can hold much more data than a CD. DVD manufacturers are already devising writable DVDs. This could become an ideal medium for backing-up large amounts of data, such as a company’s database, that currently needs to be stored on tape. DVDs would not only make the process of backing-up faster, but would also consolidate the back-up. The entire database could be stored on just a few slim DVDs, as opposed to several bulky tapes. Storage of large amounts of data on DVDs, such as databases or plans for items a company manufactures (be it buildings, cars, or widgets), may eventually create a trickle-down effect of savings to consumers—or larger profits for the manufacturers.
It is also likely that DVD will have an impact on networks and their usage. In order to transmit the amount of data contained on a DVD, a more advanced means of transport would be necessary. Even if a POTS line could support the amount of data, it would take a very long time to transmit. ISDN lines may not even be enough. What this implies is that the more advanced means of transporting data over networks will need to be made available to the general population, whereas they are only available in some areas at the moment. These lines will also need to be offered at an affordable price, so that the average consumer can afford the service.
It is difficult to say exactly what impacts DVD will have on the computer
and telecommunications industries. However, by following the path
of the CD’s impact on these industries and tracking the trends of DVD,
we wish to present a proposal of what DVD might be expected to do in the
future.
The largest impact is happening in the field of home entertainment. DVD video can offer state-of-the-art visual enhancements for a superior video experience. Movie lovers don’t need to go to a theater to watch movie. With a DVD video, they can conveniently sit at home to enjoy a movie having theater-quality Dolby Digital Sound and an exceptional picture. Compared to regular video, DVD video is easy to use; there is no rewinding or jamming. It also won’t degrade or wear out. The price of DVD is comparable to many videotapes and less expensive than laser discs. Typically they sell for less than $25. The affordability of DVD movie and music videos is the principal reason for the popularity of DVD.
According to the estimation of the DVD Video Group, approximately 500,000 players have been sold to date since DVD video was first launched in late 1997, compared to just 35,000 compact disc players sold in that format’s first year in 1983. On the software side, the DVD Video Group projects that the number of titles to be released in 1998 will bring the total number of available titles to approximately 1,500.
The impact of DVD on computer electronics companies is also extensive. Most of the computer electronics companies have a DVD research and development division to support DVD technology. JVC Company of America, Panasonic Consumer Electronics Company, Philips Consumer Electronics Company, Pioneer Electronics (USA), Samsung North America, Sony Electronics, and Toshiba are among the manufacturers that currently produce DVD video players and DVD-ROM drives.
Since DVD can hold twenty-five times the data of a CD, it’s extremely
useful for those organizations which need a large amount disk space to
store data files. Applications such as mapping programs and phone number
databases, which now span several CDs, will be much more efficient if DVD
is used to store their data. For example, Microsoft’s best-selling Encarta
spans two CD-ROMs. DVD can store it on one disk!