Abstract: A method, device and system for selecting a security algorithm are provided. The method includes: a core network receives an attachment request initiated to a broadband cluster network by a first terminal (UE), wherein the attachment request carries first security capability information supported by the first UE; the core network determines a group to which the first UE belongs, and obtains security capability information of each second UE in the group; and the core network selects a security algorithm supported by both the security capability information of the first UE and the security capability information of each second UE; and sends the selected security algorithm to the first UE as a security algorithm of the group.

Abstract: The present invention provides a device and method for realizing prefix code construction. The device includes a sort indexer, a generator and a sequence regulator. The sort indexer is used to sort a group of received code lengths to obtain a group of sorted code lengths, and record the position correspondence relationship. The generator receives the sorted code lengths and orderly generates the prefix codes. Except that the first prefix code is preconfigured, the generator generates a current prefix code by adding one to the adjacently previous prefix code and then shifting left by a certain number of bits. The sequence regulator is used to receive the prefix codes corresponding to the sorted code lengths, and regulates the sequence of the prefix codes corresponding to the sorted code lengths according to the position correspondence relationship recorded by the sort indexer to obtain the prefix codes corresponding to the code lengths.

Abstract: The present invention provides a device and method for realizing prefix code construction. The device includes a sort indexer, a generator and a sequence regulator. The sort indexer is used to sort a group of received code lengths to obtain a group of sorted code lengths, and record the position correspondence relationship. The generator receives the sorted code lengths and orderly generates the prefix codes. Except that the first prefix code is preconfigured, the generator generates a current prefix code by adding one to the adjacently previous prefix code and then shifting left by a certain number of bits. When the current prefix code is generated, the generator simultaneously judges whether the adjacently previous prefix code is identical to the current prefix code from the high bit, if yes, the error information is outputted; otherwise the prefix codes corresponding to the sorted code lengths are generated.