|-------------  SCHC Fragment Header -----------|
+-----------------------------------------------+--------------+
| RuleID |   W    | FCN=ALL-1 |  RCS   |b'00000 |   Payload    |
+--------+--------+-----------+--------+--------+--------------+
| 3 bits | 2 bits |  3 bits   | 3 bits | 5 bits | 0 to 80 bits |