January/February 1996 -- Volume 8 Number 1
CableLabs research and development has focused on the evolution of the hybrid fiber/coax (HFC) network and the deployment of new services. CableLabs has developed a mix of the core competencies needed for this evolution in areas such as digital coding and transmission, advanced television, cable telephony, cable data modems, network intelligence and software support systems, two-way network functionality, and financial modeling.
The project planning process, instituted in 1994, selects projects that apply to an integrated view of the expanded services network, the steps necessary to get there, and the deployment of new services. CableLabs management selects projects through an integrated review by all members of the technical staff and, where appropriate, its governance that includes the Board of Directors, the Executive Committee, a Technical Advisory Committee and Technical Advisory Steering Subcommittee.
Funds from the project pool (and staff resources) are allocated on an ongoing, iterative basis and then only to project ideas that are approved as part of the project planning process. CableLabs uses consultants where they add value to support technical staff in R&D projects.
In 1996, CableLabs will weigh heavily its project funding based on how the projects fit under its strategic initiatives. These initiatives follow:
In addition, OTP is involved in the open interface specification process that is a key element in the industry's strategy on cable data service delivery. This project will produce a series of open specifications for the key interfaces in a cable data network. These interfaces may be between a modem, the cable plant, the cable headend and service providers. One goal is to foster interoperability so that the consumer equipment is interchangeable and may be sold at retail once the technology is more mature. The project team is working with a small group of members and will solicit input from all the interested parties, including the supplier community. Further, it will support the technical open specifications and participate in the coordination of comments and creation of the open specifications. The first of the open specifications are slated to be released by mid-year, with the intent to complete the more complex open specifications before the year end.
One of the issues cable operators must address in deploying new services is added costs. The OTP department is developing network migration models and economic case studies for presentation to member companies addressing the significant operating and capital costs and revenues associated with various broadband digital network architectures and services. It also is conducting work to gain a better understanding of network reliability issues and technology.
Working with the High-Speed Data working group, CableLabs issued an RFP for High- Speed Data Services over HFC systems. CableLabs has hired consultants to assist in the review of HSD RFP responses, to assist in the development of test methodologies and testing platforms, to perform network modeling functions and to analyze protocol designs. The first phase of testing will collect fundamental data and specific network test results that will be critical to understanding how well a modem will perform with typical transmission impairments. These data will be used to clarify and to help explain the throughput and latency performance behavior of well-defined PC applications and platforms.
The OTP department, along with CableLabs Technical Services department, will administer a project involving a newly acquired Nortel DMS 500 telephone switch. This project will help CableLabs gain a greater understanding of the various issues facing the cable industry in delivering telephony, data and other new telecommunications services.
CableLabs, through OTP, will create an aggressive agenda for wireless technologies. Work in this area will include wireless voice as well as wireless data transmission. Another major area of work for OTP will be in integrated systems and enterprise management. Cable operators today largely rely on their customers for network management of the downstream broadcast video service. With the transition to multiple digital telecommunications services, cable operators require a more proactive approach to services management. CableLabs intends to explore some specific areas where it can help members make this transition.
Engineering
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The Engineering department conducts the technical and operational engineering activities of CableLabs. These activities include managing resources that are used for performing theoretical and applied assessments and for providing laboratory and field evaluations of new technologies for compression, storage, transmission and presentation of information on cable networks. This department is responsible for physical platform issues associated with expanded-service cable television networks. Engineering also provides continuing assessment of emerging transmission technologies, and supports other departments in areas of digital compression and transmission, including MPEG-2 development efforts, digital video delivery, high-speed data, telephony and wireless communications.
Engineering will continue its cable system characterization work to obtain and to analyze field data for use in characterizing the upstream and downstream transmission channel performance of two-way cable systems. The work also will help in determining the impediments to digital transmission and in suggesting solutions to improve the reliability and robustness of the two-way cable system.
The first phase of this project, performed in conjunction with member companies, studied the nature of downstream transmissions on cable. The goal was to understand better the mechanisms causing downstream signal impairments, and to determine ways to build, operate, and maintain cable facilities that provide a reliable and consistent communications channel.
The second phase of this project, started in the summer of 1995, is collecting long-term data from member company two-way activated plants using a CableLabs-developed unique test platform with data acquisition tools, the CWTesterª. The tests are currently ongoing in cooperation with field trials in several member companies' systems.
The third phase of the CWTesterª is the data analysis tool developed by the Engineering staff. This interactive tool facilitates the analysis of the two-way characteristics.
The data gathered from the upstream characterization will be integrated into the Cable Test System (CTS) to allow controllable and repeatable laboratory testing of two-way cable equipment under real-world conditions. Data modems will be tested first with the enhanced two-way test platform.
Through CableLabs facilities, Engineering also will provide a venue for the verification of interoperability of MPEG-2 bit streams. This work will further CableLabs' objective of fostering interoperability among and between the various physical distribution platforms anticipated for future digital services. The project utilizes CableLabs' conformance testing laboratory facilities in Louisville, Colorado, as an international venue to test and verify the bit streams to determine their compliance with the MPEG-2 standard.
Using a common, agreed-upon interface, the project would test the video, audio, data, and synchronization when all these components are multiplexed into a transport stream. In addition, tests would be carried out on baseband data streams after demodulation. CableLabs may expand the scope of this project to test encoders and decoders on an end-to-end basis. CableLabs also may examine complete encoding-distribution-decoding networks.
Engineering is also performing MPEG-2 Digital Video Compression subjective quality assessment. Engineering has obtained video test material with proven MPEG-2 test sequences, as well as sequences of more typical cable programming. This test material will be used to provide comparative assessments of video compression technologies.
The output of each vendor's encoder/decoder will be tape recorded with a studio-quality digital component videotape recorder. The tapes will be edited and then viewed on studio-quality, 525-line component picture monitors for picture quality evaluation by selected expert viewers. The output tapes will be used to provide subjective viewing comparisons, allowing side-by-side comparisons of several implementations of various MPEG-2 profiles and subsets, as well as non-standard DigiCipher extensions.
In addition, Engineering will be conducting tests on digital QAM modems, cable data modems, telephony modems and wireless radio antenna drivers (RAD).
Communications and Technology Transfer (CATT)
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In addition to providing publishing support to other CableLabs departments and shepherding an increased CableLabs focus on technology transfer, CATT works closely with Technical Services on the CableNETª activity.
CableNETª is designed to help demonstrate the cable industry's interest in leading-edge technology. CableLabs has created several technology demonstrations, such as CableNETª. These projects are important to the cable industry because they: (1) bring new suppliers into the industry, (2) educate audiences on cable's technological capabilities, (3) promote CableLabs and reinforce its contributions in the technological aspects of the telecommunications process, and (4) inform CableLabs members about the technologies.
CableLabs is very interested in helping to enhance and to expand the cable industry's presence on the World Wide Web. In addition to the CableLabs sites at http://www.cablelabs.com and http://www.cablenet.org, CableLabs will create a site in which to prototype newer Internet technologies, such as video and audio streaming, multimedia delivery, and secure business transactions.
CableLabs has expanded its Web site to include a Members-Only location. This area is password protected. It allows members to access news services, publications restricted to members, and bulletin boards on various topics of interest to members.
Once again CableLabs will update its study of consumer perceptions of cable. This project focuses on gathering data about consumer perceptions when cable service is lost. It should help member companies gauge the importance of system reliability to their customers and also show perceptions of consumers of cable, direct broadcast satellite (DBS), telephone and wireless cable service.
Technical Services
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The Technical Services department provides the information services, telecommunications, cable services, broadband video/audio, video editing and audiovisual needs of all CableLabs departments.
Technical Services maintains the internal CableLabs local area network and Internet connectivity and supports engineering and systems integration. The department maintains the in-house cable plant; integrates voice, video, and data telecommunications for the company; and provides technical audiovisual support for all meetings, seminars, and conferences.
Technical Services coordinates and maintains the technical demonstration showroom, integrating new technologies using voice, video, and data, and coordinates tours with the CATT department. It also serves as technical coordinator for the CableNETª demonstrations at the Western Cable Show and for the various other demonstrations in which CableLabs may participate. The department is continuing to upgrade connectivity and design and to build Internet protocol (IP) networks at CableLabs to support high-speed cable data
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