MPEG IPR Backgrounder

Q: What is digital compression and why is it important?

A: Digital compression is the process of digitizing an analog television signal, in this case efficiently coding a TV picture to "1s" and "0s." The use of compressed digital video instead of analog video dramatically lowers video distribution costs, increases quality and security, and allows interactivity. Some examples:

  • On a US cable television system, for example, compression would allow a cable television system operator to carry four to 10 television signals on one cable television channel that now carries one service.
  • In the US, it costs $6 million (U.S.) per year to rent a satellite transponder to distribute a single television channel, such as Turner Network Television (TNT). With compressed digital video, four video channels may be carried on one transponder, cutting their transponder costs by 75% per channel.
  • Analog video collects noise (snow, ghosts) as it travels over the air and through cable to homes; digital video arrives exactly as it was sent -- sharp, clear, and undistorted.
  • Q: What is MPEG?

    A: MPEG stands for Moving Picture Experts Group. MPEG is a working group convened under the joint supervision of the International Standards Organization (ISO) and the International Electro-technical Commission (IEC). MPEG is officially working group 11. MPEG's mandate is to develop standards for coded representation of moving pictures and associated audio and other information. As such, it is an international standards process aimed at achieving a standard which specifies the coded bitstream and decoder requirements for high quality digital video and associated audio. This includes multiplexing multiple video, audio, and program information streams for transport or storage.

    The MPEG standard is generally referred to as either MPEG 1 or MPEG 2.

    Q: What is the difference between MPEG 1 and MPEG 2?

    A: The original goal of the MPEG committee was to create a standard for the delivery of video and audio on a compact disc. The committee specifically targeted bitrates of around 1.2 Mbits per second (Mbps) for video and 250 kilobits per second (kbps) for 2-channel stereo audio. They succeeded and that original standard is known as MPEG 1.

    Distribution network industries, such as cable television, realizing the potential of digital compression technology to increase services and lower costs, liked the MPEG concept but were not limited by CD data rates. Consequently, MPEG developed a second effort that takes advantage of the higher bandwidths (data rates) available to these networks to deliver higher image resolution and picture quality. Specifically, this effort targeted increased image quality in ranges from about 3 to 15 Mbps, support of interlaced video formats, and provision for multi-resolution scalability. New audio features included encodng of multi-channel audio and very-low bit rate stereo. This effort is known as MPEG 2.

    Q: Is MPEG 1 an official standard?

    A: Yes. MPEG 1 (formally ISO/IEC IS 11172) is a three-part standard (Systems, Video and Audio) ratified by the International Standards Organization (ISO) and was published in August 1993.

    Q: Is MPEG 2 an official standard?

    A: No, it has not yet been ratified formally by the member countries of the ISO. However, the technical work -- the committee draft -- was approved at the MPEG meeting in Seoul, Republic of Korea, in November 1993. (The video portion of the standard, which is the most difficult portion to implement, received unanimous approval from the 140 video committee members in Sydney, Australia, in April 1993.)

    Further, at its March 21-25, 1994, meeting, MPEG elevated the video and audio portions of its technical work to DIS (Draft International Standard) status. The systems portion of its work was elevated to DIS status after a meeting June 8-10, 1994. The three-part standard of MPEG-2 (Systems, Video, and Audio) was elevated to International Standard status at MPEG's 29th meeting which was held in Singapore, November 7-11, 1994.

    Q: What is the MPEG IPR Group and what work has it undertaken so far regarding resolution of this MPEG IPR issue?

    A: As a result of the activities of informal meetings regarding MPEG IPR matters held at the MPEG meetings in London in November 1992, and in Rome in January 1993, ad hoc groups regarding MPEG IPR issues were formed between the Rome and Sydney (March 1993) meetings and between the Sydney and New York (July 1993) meetings of WG 11.

    Based upon this work, at the New York MPEG meeting, Resolution 3.9.6. was adopted recommending that WG 11 "support an initiative leading to the establishment of a patent pool for MPEG-2, outside of MPEG,...WG 11 expresses its support for the (outside of MPEG) meeting of licensing experts which Mr. Baryn Futa [of Cable Television Laboratories, Inc., "CableLabs®"] has offered to convene..." This effort has proceeded as an effort outside of MPEG and is not an ad hoc group or another form of MPEG activity. This outside discussion is called the MPEG IPR Group and it has held three meetings.

    Following a series of meetings held in 1993 and 1994, the MPEG IPR Group reached a consensus on a two-phase action plan for establishing a licensing entity. Part of this plan was for companies to complete a form letter indicating their interest in working to create a licensing entity and to provide a list of their MPEG-related patents. Subsequently, a Working Group of nine companies was formed.

    The group established the following as the mission to be achieved by the establishment of a licensing entity: To foster fair, reasonable, and nondiscriminatory access to as much relevant IPR as is possible for the implementation of digital television. The group has continued its work through 1995 and it is the Working Group's proposal which was presented at the Lausanne meeting.

    Q: When will cable television operators and other programming distributors as well as worldwide consumer electronic companies begin deploying this digital technology for customers?

    A: It is anticipated that the technology will be deployed beginning in third quarter 1995.

    Q: What does interoperability mean in this digital context? Why is it so important?

    A: Generally speaking, interoperability means the ability for system components to function properly with other system components from a different manufacturer or service provider. In the digital context, this means the ability for different software, hardware, and network components to communicate effectively and operate satisfactorily as an end-to-end system.

    Interoperability is important because it would allow communications among and between different consumers without regard to the software, hardware or network that they use.

    Q: What is CableLabs and why is CableLabs so interested in digital compression and the MPEG intellectual property issues?

    A: CableLabs® is a research and development consortium of cable television system operators representing more than 85% of the cable television subscribers in the United States, 70% of the cable television subscribers in Canada, and 5-10% of cable television subscribers in Mexico. CableLabs plans and funds research and development projects that will help cable companies take advantage of future opportunities and meet future challenges in the television industry. It also transfers relevant technologies to member companies and to the industry. In addition, CableLabs acts as a clearinghouse to provide information on current and prospective technological developments that are of interest to the cable television industry.

    In the United States, 63 percent of the 93 million television households receive cable television service while 95 percent of all television households are "passed" (have access to) cable television service. In Canada, the numbers are 73 percent of the 10.1 million television households receive cable television service and95 percent passed.

    CableLabs' objective is to foster interoperability and ubiquity among and between the various distribution network platforms (cable, telephony, DBS, wireless, etc.) as well as the various forms of source material that these networks will distribute and transmit (video entertainment, video telephony, applications software, etc.) A brief synopsis of these efforts follows:

  • In July 1989 and in May 1990, CableLabs® announced its formal High Definition Television Testing program to be undertaken at the Advanced Television Test Center in Alexandria, Virginia, USA. This program, which will completed at the end of this year, has resulted in cable television system testing of all of the HDTV system proponents under consideration by the Advisory Committee on Advanced Television Service of the Federal Communications Commission. These systems, as you know, are digital. The final, blended system, called the Grand Alliance, also is digital.


  • In March 1991, CableLabs, General Instrument Corporation and Scientific-Atlanta formed a cable digital transmission consortium to bring awareness to digital compression technology and cable television's role at the forefront of the development of digital and compression technologies. In September 1991, CableLabs spearheaded the efforts of Tele-Communications, Inc. (TCI), the Viacom Networks unit of Viacom International, Inc. (Viacom) and the Public Broadcasting Service (PBS) in the joint issuance of a Request for Proposal (RFP) for the acquisition of equipment of a digital compression program delivery system.

    In both of these efforts, CableLabs has served as a facilitator and technical resource to the industry in the exploration of this technology. The RFP was successful in not only focusing worldwide attention and interest in the application of this technology to the cable environment, but it also served to hasten the development of digital compression hardware in the context of worldwide recognition that the cable industry would be at the leading edge of mass scale implementation of such technology. As of today, RFP participants TCI and Viacom and PBS have announced their intentions to acquire digital compression products from General Instrument, Scientific-Atlanta and Hewlett-Packard.

    Overall, nine major North American cable operators have signaled their interest in deploying digital home terminals by ordering a total of about 2.75 million units. The operators and their announced plans: TCI, 1.4 million units; Comcast, 150,000; Century Cable, 300,000; Newhouse Broadcasting, 250,000; Cox Cable, 200,000; Shaw Communications Inc., 200,000; Cablevision Industries, 125,000; Adelphia Cable, 120,000; Sammons Communications, 70,000; TeleCable, 50,000. (Source: Multichannel News, January 3, 1994 issue)


  • In December 1991, CableLabs formed the Compressed Digital Commercial/Program Insertion Task Force which issued an Request of Information (RFI) to explore the use of digital compression technology to provide for commercial insertion on cable television systems. Forty three responses to the RFI were received.


  • CableLabs has been an active participant in the Moving Pictures Experts Group (MPEG) in development of the MPEG 2 digital compression standard. [Background on MPEG above]. This effort has included active involvement in the technical work of MPEG as well as taking a leadership role in the development of solutions regarding the fair and nondiscriminatory availability of patent rights to the core digital compression technology of MPEG as discussed in this press release.


  • And, as part of its technology transfer mission, CableLabs has sponsored numerous conferences, and seminars have been held by CableLabs on the topic of digital compression technology.