In one aspect the present invention describes an electronic circuit for transmitting
voice packet data over a wireless network with an upstream transmission mode and
a downstream transmission mode. The circuit comprises a first phase-lock loop (PLL)
for locking a first clock to a time stamp signal, wherein the first clock synchronizes
upstream data transmission over the wireless network; and a second PLL for locking
a second clock to the time stamp signal, wherein the second clock is used for sampling
voice data for downstream voice data transmission over the wireless network.