SMC wireless adapter on Acer laptop

Currently I access the internet on my Acer Laptop using a wireless
connection over an SMC laptop adapter and my SMC router which has been
connected to a Thompson Speed Touch 510 ADSL modem.

For some time past I have had the problem that during my internet
sessions the wireless connection repeatedly wants to renew my IP
address, resulting in the connection to getg lost several times while it
disconnects, then reconnects and then renews the IP address.

Does anybody recognizes this problem and if so, what is the cause and
how exactly can it be fixed?

Thanks in advance for you replies.

Charles.