Transforming TETRA Testing: Assessing the Feasibility of Modern Framework Adoption

Motorola Solutions' DIMETRA TETRA infrastructure utilizes the TETRA radio communication protocol, essential for European public safety, rail, and military networks. Relying on proprietary testing frameworks, the company seeks to modernize its testing processes. This research analyzes the feasibility of migrating the DIMETRA Zone Controller (ZC) testing from the legacy Generic Link Simulator (GLS) to the modern Java-based Marion framework. The study evaluates efficiency, maintainability, cost, and ease of migration to recommend a framework aligned with Motorola Solutions' long-term goals. GLS, a specialized tool designed for ZC testing, offers efficient packet handling and a simple syntax, but suffers from limitations in code maintainability, extensibility, and the absence of modern software engineering practices. Marion, leveraging Java's object-oriented features, annotation-driven test cases, and the TTCN-3 language for PDU definitions, offers advantages in modularity, code reuse, and a more structured approach. However, its multi-layered architecture and initial focus on the Tetra Site Controller (TSC) present challenges for ZC-specific adaptation. The research involved a deep dive into various protocols, including SNMP and Netcom, analyzing packet characteristics, transmission types between stations, and connections within Service Access Points (SAP). This necessitated creating test cases within both frameworks, coding new structures to adapt message content between different programming languages, and implementing code for message parsing and processing. A key challenge involved replicating GLS's specialized functions, within Marion to maintain testing parity. Furthermore, addressing MIB compiler compatibility issues for SNMP and adapting the Netcom protocol for bidirectional ZC-TSC communication required significant effort. A ZC prototype was developed within Marion, including the adaptation of existing infrastructure and the creation of ZC-specific configuration files. This involved defining new ports, managing IP addresses, and setting up virtual machines for a reproducible testing environment. Exported test cases on the new platform demonstrate the prototype's functionality and provide a glimpse into the migrated testing landscape. The research includes a comparative analysis of GLS and Marion, highlighting the advantages and disadvantages of each system. This analysis considered factors such as code structure, test case organization, handling of data formats, and the speed of packet processing. A key finding was the crucial importance of comprehensive documentation, addressing existing gaps in both GLS and Marion, particularly regarding ZC-specific configurations, MIB file definitions, and overall framework functionalities. A structured test case template for ZC within Marion was developed, promoting consistency, readability, and maintainability for future development. This template provides a foundation for organizing test cases, incorporating setup and cleanup procedures, and grouping related tests, facilitating easier management and extension of the test suite. The prototype and test case template represent a substantial investment by Motorola Solutions, acknowledging the considerable time and resources required for a complete migration. The findings suggest that while challenging, migrating to Marion offers significant long-term benefits in terms of maintainability, adaptability, and integration with other testing processes.