TTCN-3 Codec Implementation for LTE RRM Conformance Test

Radio Resource Management (RRM) is a system level control of co-channel interference and other radio transmission characteristics in Long Term Evolution (LTE) systems. Testing and Test Control Notation (TTCN-3) is an international standardized abstract programming language for test development. Its abstraction, scalability and standardization of interfaces make TTCN-3 the best choice for implementing the RRM test suite. As an important entity in testing systems, the codec encodes TTCN-3 values into a bitstring according to the encoding rule, and decodes a bitstring according to decoding hypothesis. There are 13 kinds of message type definitions and seven encoding rules in the RRM conformance testing system, so the developers should implement multiple codecs according to different encoding rules. This paper mainly focuses on the common programming method for the codecs required by the RRM test suite. First, the significance of codecs in TTCN-3 testing systems is explained, then the TTCN-3 Control Interface is introduced, and finally the implementation of codecs for specific type definitions in the RRM conformance testing system is shown.