Used by Ethernet, most popular LAN technology
Defines a bit value by a mid-bit transition
- A high to low voltage transition is a 0 and a low to high mid-bit transition defines a 1
Data rates: 10 Mb/s, 100 Mb/s, 1 Gb/s, ..
- 10- Mb/s ? one signal for every 1/10,000,000 of a second (10 million signals (bits) every second)
Less susceptible to having errors go undetected
- No transition ? en error took place