Increasing traffic density for the highway maintenance depots means a higher amount of services: The number of emergency calls and accidents grows, maintenance and construction work increases, snow removal and spreader services must be performed even faster and, at the same time, cover larger areas. That requires a reliable, fast and effective coordination of all task forces. A prerequisite is a reliable voice and data communication system that connects the central office, the respective base on site and the mobile task force units on the roads.

Consequently, the highway services of Saxony considered our TETRA wireless system ACCESSNET-T IP as the only ideal solution. The IP-based networking utilizes already existing locations as well as IP connection paths, thereby significantly reducing the costs for setting up the entire system. In particular, ACCESSNET-T IP easily adapts itself to all requirements: It can be expanded flexibly, its non hierarchical network structure is topologically independent, it offers the highest possible fault tolerance through intelligent redundancy functions and robust system design.

For the highway services of Saxony, we implemented an individually tailored ACCESSNET-T network according to the TETRA standard. At the centre are seven switching nodes – one for each highway maintenance depot. Each of these units can operate independently in case of system failures and, thanks to the highly redundant concept, take over the tasks of failed switching nodes. After fault removal, the switching nodes synchronize themselves so that all the data continue to be available. The switching nodes organize the entire traffic of all 28 base stations and support a total of 56 TETRA carriers.

In addition, we integrated special applications into the digital wireless system upon request from the highway services of Saxony: IP wire control stations, repeaters for the tunnel supply as well as a fieldoriented, decentralized fleet management system. It ensures every highway maintenance depot that it has quick access and full control, specifically over its portion of the vehicle fleet.