Abstract: A communication device with a short message filter mechanism. The communication device comprises an incoming phone number filter module for acquiring the number of digits in an incoming phone number accompanying a short message received by the communication device and, if the number of digits in the incoming phone number is less than a preset value, deleting the short message, and a keyword filter module for determining whether the short message contains a specific keyword and, if so, deleting the short message.

Abstract: This invention discloses a method of transmitting data through Local Area Network by abandoning the Transmission Control Protocol/Internet Protocol (TCP/IP) to eliminate the Address Resolution Protocol (ARP) and avoid unnecessary delay and communication flow. The present invention also abandons the concept of TCP/IP address, so that it is not necessary to maintain the huge TCP/IP address database in wireless LAN in order to implement the gapless roaming and reduce packet conflict during the transmission process by defining a smaller capacity for the data packet head in the high-speed wireless LAN standard IEEE 802.11 protocol.

Abstract: A method for applying for crypto-keys from a network system. The network system includes at least a user, an access point for identifying the user, and a server for generating a pair of distinct crypto-keys based on a first algorithm. The method includes using the access point to identify the user, and the server generating a pair of distinct crypto-keys based on the first algorithm and transmitting the pair of keys to the user via the access point. The method further includes the user using the pair of keys to encrypt a document and then transmitting the encrypted document to another user.