This paper describes a polling deregistration protocol for a wireless
access communications network which would support interoperability bet
ween licensed personal communications services (PCS) and unlicensed-PC
S (UPCS), We show how the protocol can be efficiently implemented in t
he personal access communications system (PACS) for licensed PCS and i
n the PACS-Unlicensed Version B (PACS-UB), An analytical model is prop
osed to analyze the performance of the polling protocol, A cost functi
on is derived, which can be used to estimate the optimal polling frequ
ency.