2section (Continued) 6 Layer 3 Processing

2.6.6.2.6.3 Maintenance of the Neighbor Set

When the mobile station is first assigned a Forward Traffic Channel, the mobile station shall initialize the Neighbor Set to contain all the pilots specified in the most recently received Neighbor List Message, Extended Neighbor List Message or General Neighbor List Message.

The mobile station shall maintain a counter, AGE_s, for each pilot in the Neighbor Set. The mobile station shall initialize this counter to zero when it moves the pilot from the Active Set or the Candidate Set to the Neighbor Set. The mobile station shall initialize this counter to NGHBR_MAX_AGE_s when it moves the pilot from the Remaining Set to the Neighbor Set. The mobile station shall increment AGE_s for each pilot in the Neighbor Set upon receipt of a Neighbor List Update Message or an Extended Neighbor List Update Message. When the mobile station is first assigned to a Forward Traffic Channel, the mobile station shall set AGE_s for each pilot in the Neighbor Set to NGHBR_MAX_AGE_s.

The mobile station shall adjust the Neighbor Set whenever any of the following events occur:

• If the mobile station receives a Neighbor List Update Message or an Extended Neighbor List Update Message, it shall perform the following:

– Increment AGE_s for each pilot in the Neighbor Set.

– Delete from the Neighbor Set all pilots whose AGE_s exceeds NGHBR_MAX_AGE_s.

– Add to the Neighbor Set each pilot named in the message, if it is not already a pilot of the Active Set, Candidate Set, or Neighbor Set. If the mobile station can store in the Neighbor Set only k additional pilots, and more than k new pilots were sent in the Neighbor List Update Message or the Extended Neighbor List Update Message, the mobile station shall store the first k new pilots listed in the message.

• If the handoff drop timer of a pilot in the Candidate Set expires, the mobile station shall add the pilot to the Neighbor Set.

• If P_REV_IN_USE_s is less than or equal to three or SOFT_SLOPE_s is equal to ‘000000’, the mobile station shall perform the following:

– If the mobile station processes an Extended Handoff Direction Message, a General Handoff Direction Message, or a Universal Handoff Direction Message in which a pilot in the Active Set is not listed, and the handoff drop timer corresponding to the pilot has expired, the mobile station shall add the pilot to the Neighbor Set.

– If the mobile station autonomously drops an existing pilot in the Active Set (see 2.6.6.2.6.1) and the handoff drop timer corresponding to the pilot has expired, the mobile station shall add the pilot to the Neighbor Set.

• If P_REV_IN_USE_s is greater than three, and SOFT_SLOPE_s is not equal to ‘000000’, the mobile station shall perform the following:

– If the mobile station processes an Extended Handoff Direction Message, a General Handoff Direction Message, or a Universal Handoff Direction Message which does not list a pilot in the current Active Set, the handoff drop timer corresponding to that pilot has expired, and that pilot is found to be below T_DROP_s, the mobile station shall add the pilot to the Neighbor Set.

– If the mobile station autonomously drops an existing pilot in the Active Set (see 2.6.6.2.6.1), the handoff drop timer corresponding to that pilot has expired, and that pilot is found to be below T_DROP_s, the mobile station shall add the pilot to the Neighbor Set.

• If the mobile station adds a pilot to the Candidate Set, and the resulting Candidate Set size exceeds the size supported by the mobile station, the mobile station shall add the deleted Candidate Set pilot to the Neighbor Set (see 2.6.6.2.6.2).

• If the mobile station detects that the strength of a Neighbor Set pilot exceeds T_ADD_s, the mobile station shall delete the pilot from the Neighbor Set.

• If the mobile station processes an Extended Handoff Direction Message, a General Handoff Direction Message or a Universal Handoff Direction Message which lists a pilot in the current Neighbor Set, the mobile station shall delete the pilot from the Neighbor Set.

• If the mobile station adds a pilot to the Neighbor Set, and the resulting Neighbor Set size exceeds the size supported by the mobile station, the mobile station shall delete from the Neighbor Set the pilot whose AGE_s is the largest. If more than one such pilot exists, the mobile station shall delete one such pilot that has the lowest strength.