In the Eastern Ruhr Area Cooperative (Kooperation Östliches Ruhrgebiet, KÖR), three transport operators and a group of companies are working closely together: the Bochum-Gelsenkirchener Straßenbahnen AG (BOGESTRA, trams of Bochum-Gelsenkirchen), the Straßenbahn Herne-Castrop-Rauxel GmbH (HCR, trams of Herne-Castrop-Rauxel), the Vestische Straßenbahnen GmbH (Vestian, trams of Recklinghausen region) and the Dortmunder Stadtwerke (DSW21, Dortmund municipal works). In 2006, KÖR decided to raise its voice and data communicationto the digital TETRA standard. Their order for us: to optimize the output and performance of their existing ITCS dispatch centre application (Intermodal Transport Control System) with the help of a powerful ACCESSNET®-T mobile radio solution.
The ITCS of KÖR coordinates all the busses, trams and underground trains using a computer-controlled traffic management system. It controls the voice and data communication between dispatch centres and vehicles. For this purpose, the ITCS also integrates status and location data of the vehicles from AVLS and GIS applications. KÖR handles one of the largest and most frequently used local public transport networks in Germany. A smooth operation and intelligent integration of the ITCS impose high demands on the mobile radio network: It must be able to integrate a multitude of users as well as quickly process enormous quantities of information and formats. At the same time, it must be robust, interference-resistant, safe against manipulations and expandable.
For this reason, there was hardly a way for KÖR to get around our ACCESSNET®-T mobile radio solution. It is nearly endlessly scalable and covers all the network units from the control centre down to the individual radio transceiver. It fits perfectly into the existing system technology, ensures maximum security in the voice and data communication, optimizes the data management and also integrates non-system components. But any technology is only as good as the concept behind it. Particularly at this point, we were able to demonstrate all of our strength: our know-how in comprehensive project management and our close proximity to the customer which allows us to recognise individual demand and implement it in tailored solutions.
After a detailed inventory and demand analysis, we implemented an individual ACCESSNET®-T network according to the TETRA standard for KÖR. The core of the system is formed by two central switching nodes. They work redundantly, i.e. if one fails, the other automatically takes over its functions to prevent breakdowns.
Together, both switching nodes check a total of 28 base stations in indoor and outdoor operation. As requested by KÖR, each station features two or three TETRA carriers, giving the entire network over 60.
We coupled the ITCS to the control centres, which are independent of each other, of the three KÖR transport operators. Each includes ten AVLS and GIS-compatible dispatcher workstations. The network management of Rohde & Schwarz is just as well thought-out as the structure of this powerful system. With a view to the highest operational security, we organizedit decentrally: The software application can be operated from four different service and maintenance centres and connected with the ACCESSNET®-T network via WAN.
The trunked radio network of KÖR features over 1000 radio terminals in form of on-board systems and handheld devices. The storage of information - important for analysis and documentation purposes - is reliably accomplished by the TETRA voice recorder. Similar to the A-CAPI® interface, it is redundantly connected to the TETRA system and ensures a smooth recording of the data even if a voice recorder should fail.
Highlights of our solution
- Region-based group communication for efficient utilisatio nof local resources
- SDS transmission to active terminals in group communication
- Optimization of the entire network for high data load (SDS) by using secondary control channels (SCCH)
- Pre-emptive calls in group communication
- Late Entry
- Concurrent emergency call transmission to various recipients; this allows emergency information to reach the correct recipient at all times
- Packet data transmission