to The Great Telecom Meltdown around 350 MHz, allowing perhaps 50 channels per cable. CableLabs, an organization sponsored by a number of multiple system operators (MSOs), commissioned the consulting firm Arthur D. Little Inc. (ADL) to study the role of fiber optics in the CATV industry. The ADL study determined that the most cost-effective architecture would use low-loss fiber optics (in analog mode, car- rying the radio frequency spectrum modulated onto light) for the relatively long-haul trunking between the head end and the neighborhood, with coaxial cable, and no more than three amplifiers, for the final subscriber drops. This scheme came to be known as hybrid fiber-coax (HFC) and was adopted univer- sally by the industry. During the 1990s and beyond, virtually all new cable builds used HFC architecture, whereas older systems were upgraded by replacing the old coaxial trunks with optical fiber. This resulted in two-way networks with greatly increased bandwidth (550 to 890 MHz) and thus far more channel capacity. It also meant that the cable companies, not the ILECs, were the ones with fiber in the residential neighborhoods and the ones with high-speed two-way transmis- sion into the most homes. Although the ILECs were promoting digital sub- scriber line services, those were very sensitive to loop length and quality, SO roughly only half of American homes would be able to subscribe to DSL if every central office had it. HFC, on the other hand, provided uniform service throughout its coverage area, SO every home in a served franchise could get all available services. HFC can provide voice, data, and video services quite readily. In North America, where television channel 2 began at 54 MHz, frequencies below 42 MHz are generally available for upstream (reverse) transmission on the coax. (On the fiber, upstream generally uses a different strand from downstream. European systems can provide up to 65 MHz for upstream, there being little VHF television there.) However, frequencies below around 18 MHz are not suitab