ss. First, the user's computer must have an ISA or PCI card slot available in their computer for the Ethernet adapter. Also, the card installation often requires configuration work within the operating system settings to prevent conflicts with other hardware devices. Due to the complexity, cable operators are often forced to send a specialized computer technician to handle Ethernet card installations, a process that can take more than 20 minutes per subscriber. Also, the requirement of opening each customer's PC to install hardware creates a potential liability for the cable operator. Eager to avoid the Ethernet card headache, cable operators have searched for an alternate approach. The solution they have found lies is a device nicknamed a "dongle," which is a Universal Serial Bus (USB) adapter. USB is a "plug-and-play" technology for connecting peripheral devices to computers, including modems, keyboards, printers and scanners (Van Matre, 1999). USB ports are external interfaces, so there's no need to open the computer to install a USB device. External Universal Serial Bus (USB) modems and internal PCI modem cards are under development. Cable modems receive data much faster than they can send it. Cable modem manufacturers have designed their modems to use less than a full 6 MHz carrier channel for upstream traffic. Typically 2 MHz wide bands are used for upstream data traffic. Cable TV networks transfer data using sophisticated digital modulation schemes which greatly increase the amount of data that can be sent. 64-state quadrature amplitude modulation (64 QAM) is digital modulation technique used for sending data downstream over a coaxial-only cable network. A single downstream 6 MHz television channel may support up to 27 Mbps of downstream data throughput from the cable head-end using 64 QAM transmission technology. HFC networks are able to implement 256 QAM, which supports 36 Mbps of downstream data throughput. Howev...
