A method for controlling Internet access of a mobile device by using a
communication system having a number of access points includes the steps
of performing a certificate-based authentication between an
authentication access point and a mobile device seeking access to the
Internet; transmitting a certificate from the mobile device to the
authentication access point; verifying the certificate by the
authentication access point; determining whether the authenticating
mobile device's certificate has been revoked prior to the expiration of
its lifetime; and granting the authenticating mobile device access to the
Internet, if the certificate has been verified successfully and not
revoked prior to the expiration of its lifetime.