DQDB is a fiber optic network with two unidirectional buses that has a maximum capacity of 150 Mb/s. It can connect up to 512 stations along 160 km with stations spaced at most 10 km apart. The network uses QPSX slotted access MAC, 8B/9B source coding, and NRZI channel coding to transmit over fiber at 1300 nm wavelength with a bit error rate of 10-9.

3. DQDB Access Protocol

4. DQDB Access Protocol (cntd..)