Methods and apparatus for use in reducing airlink congestion and
processing time associated with ciphering information communicated
between a wireless communication network and a mobile station are
disclosed. From the standpoint of the mobile station, one illustrative
method involves the steps of receiving a ciphering mode information
message from a wireless network; identifying and processing valid radio
bearer downlink ciphering activation time information in the ciphering
mode information message when it is part of a security mode command
message; and refraining from processing any valid radio bearer downlink
ciphering activation time information in the ciphering mode information
message when it is part of a message that is different from the security
mode command message (i.e. when it is part of a radio network subsystem
relocation procedure). The method may include the additional steps of
producing valid radio bearer uplink ciphering activation time information
for inclusion within a response message when the ciphering mode
information message is part of the security mode command message;
refraining from producing any valid radio bearer uplink ciphering
activation time information when the ciphering mode information message
is part of a message that is different from the security mode command
message; and causing the response message to be sent to the wireless
network.