Patent ID: 7486753

Claim:
A synchronization establishment circuit provided in a radio terminal and adapted to receive a beacon signal supplied from a remote device at a predetermined cycle and adapted to generate an internal signal in said radio terminal, comprising: a first counter for counting a timer clock from when a first beacon signal is received until a second beacon signal is received; a second counter for counting the timer clock from when said second beacon signal is received until a third beacon signal is received; a register for storing a first count value of said first counter and a second count value of said second counter; means for retrieving information about said predetermined cycle from said first beacon signal; a first comparator for comparing said first count value of said first counter with said predetermined cycle; a second comparator for comparing said second count value of said second counter with said first count value of said first counter; and a controller for determining whether synchronization is established between said second beacon signal and said internal signal based on a comparison result of said first comparator, wherein after the synchronization is established, said controller allows said radio terminal to receive/send a signal from/to said remote device when a comparison result of said second comparator indicates that said second count value matches said first count value.