Medium Access Control (MAC) and Physical Layer (PHY) - CISE

4-June-07 P1901_PRO_016_r0
- Number of Hops – 4 bits. For a Head End, the Number of Hops is equal to 0. For a TDR, the Number of
Hops is equal to the Number of Hops read in Access Token from its Master + 1. In a CPE, this field is not
used. When this field is set to 31 means that there are 32 hops or more.
- Unused frame symbols (13 bits). Unused symbols in the current frame, compared to the Validity indicated
in the token announce of the same transmission frame.
- MAC Address – 48 bits. The MAC address of the master the access reply token is addressed to.
4.4.2.9 Non-returnable data token
The Non-returnable Data Token has the following fields:
Figure 48 Access Reply Token
- Preamble – 32 bits. The preamble is equal to 0x5F73EEE2.
- Type – 4 bits. Type shall be NON-RETURNABLE (2)
- Single Validity – 4 bits. See description in 0
- Validity – 12 bits. Same meaning as in the Data Token (See 0). Since this token is non-returnable, the
validity will be fully used.
Submission page 125 UPA-OPERA