swiftly research and publish a set of high- speed cable data services interface specifications. The MCNS Data Over Cable Service Interface Specification (DOCSIS) RFP persuaded MediaOne, Rogers Cablesystems, and CableLabs to join the coalition and thereby constitute a provider organization that serves 85% of U.S. cable subscribers and 70% of Canadian subscribers. Consequently, more than 20 vendors announced plans to build products based on the MCNS DOCSIS standard in March 1997. To reduce product costs and time to market, MCNS minimized technical complexity and developed a technology solution that, although, not ideal, was adequate. In contrast, the 802.14 group had been seeking to create a standard that would provide excellent quality and stand the test of time. At the physical layer, modulation formats for digital signals, the MCNS and IEEE specifications are comparable; both MCNS and the 802.14 upstream modulation standards incorporate QPSK (quadrature phase shift keying) and 16QAM. The 802.14 specification supports the ITU's J.83 Annex A (European DVB/DAVIC), B (MCNS), and C (Japanese) standards for 64/256 QAM modulation, and provides a maximum 36 Mbps of downstream throughput per 6 MHz television channel. The media access control (MAC), which sets the rules for network access by users, is where the two significantly differ. The 802.14 group specified ATM as its default solution from the headend to the cable modem. MCNS specified a scheme that is Circuit-switched Networks based on variable-length packets and that favors the delivery of Internet Protocol (IP) traffic. Both specify a 10Base-T Ethernet connection from the cable modem to the PC. Because ATM is deterministic, it provides superior QoS for integrated delivery of video, voice, and data traffic to cable modem units (as long as the cable modem is an ATM device). The 802.14 group envisioned ATM as a long-term, flexible solution. Cable operators, whose priority was to provide high-speed Internet services to consumers, believed that ATM would add unnecessa