GLOSSARY 10/100Base-T Two common forms of Ethernet transmission that transmit data at 10 or 100 Mb/s, respectively. 8b/10b encoding An encoding method used in gigabit Ethernet, ASI video inter- connections, and other applications, in which each 8-bit binary word is replaced by 10 bits such that a minimum number of data transitions per symbol is enforced. Absorption (optical) Attenuation of optical signals due to conversion of optical energy into heat energy. Active Ethernet A FTTH technology different from PON, in which an Ethernet switch is used in the field to switch data to each home, with a dedicated fiber cable running from the switch to each home. Actives Components that handle signals and require power; examples are line amplifiers and nodes. Adaptive equalizer A circuit (or software) that compensates for signal degrada- tion in a path by adjusting taps in a delay circuit until the recovered waveform is as good as it can get. AGC Automatic gain control. Circuitry in an amplifier that senses the level of a sig- nal at the output and adjusts the gain such that the signal level is constant