A filter is composed of a filter member forming at least two opposed faces, an inner space surrounded by the filter member for accumulation of a liquid, and a coupling member establishing communication between the inner space and the outside to discharge the liquid in the inner space to the outside. The present invention also provides methods for forming at least one holographic grating in a holographic recording medium having such a photopolymerizable system. Only an authenticated application is permitted to use the local resources of the terminal or the authentication module, so that an invalid application is prevented from using the local resources. The communication protocol can also simultaneously transfer voice traffic on the first network when the first network is exchanging the IP address.