Control Frame: solicit_successor
- Periodically ask for any station to link by sending solicit_successor
- Token with sender's addr and successor's addr
- wait 2 (as in 802.3)
- If 0, then continue
- If 1, then add to ring as successor
- If 2+, then collision
- Resolve contention via binary countdown
- Timer determines how often ask for join
- No limit on how long a station will wait to enter