PHY Type Notation

Each type of PHY implement is specified by a three-fields notation.

• Data rate - if only a number, is in $Mb/s$, and if suffixed by a G, is in $Gb/s$. ^[b]
• Modulation type - indicates how encoded data is transmitted on the medium.
  • BASE, BROAD, PASS – indicates baseband, broadband, or passband signaling respectively. ^[c]
• Additional distinction - may identify characteristics of transmission or medium and, in some cases, the type of PCS encoding used.

  Table 1. Additional distinguishing symbols ^[d][e]

  Symbol	Description
  T	twisted pair
  S	850 nm short wavelength (multi-mode fiber)
  L	1300 nm long wavelength
  E or Z	1500 nm extra long wavelength (single-mode)
  B	bidirectional optics
  P	passive optical
  C	copper/twinax
  K	backplane
  F	fiber
  H	plastic optical fiber
  X	8b/10b block encoding (4B5B for Fast Ethernet)
  R	large block encoding (64b/66b)