SDN in TETRA Group Communication - Voice Switching

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Sähkötekniikan korkeakoulu | Master's thesis
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Networking Technology
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8 + 58
TETRA is an open digital trunked professional mobile radio standard developed by European Telecommunications Standard Institute, which defines the various interfaces used in PMR system. Digital Exchange for TETRA (DXT) is the core of Airbus DS TETRA network and it handles signaling, switching and management functions. Switching commands generated during the call creates necessary switch table entries in the Voice Switching Unit in the DXT. Voice frames produced in a group call in TETRA network reaches the Voice Switching Unit. The voice frames are multiplied and modified according to the participants of the group call. The modified packets are then forwarded toward the recipients. In order to provide more virtualization and avoid custom hardware, the concept of Software-Defined Networking (SDN) is used in voice switching. As a result a new system is developed, which performs the exact function of the current Voice Switching Unit. Replacement of current Voice Switching Unit with a combination of a SDN controller and a COTS SDN switch allows performing the switching of voice frames of the group call. Switching commands related to the group call are processed by the SDN application and necessary entries are made inside the SDN switch. As a result when voice frames reaches the SDN switch, the switch performs the table lookups. Upon finding the matching entry, the frames are multiplied and modified according to the details of the recipients. The concept of group tables in SDN switch helps in multiplying and modifying the packets. The modified packets are then forwarded towards the recipients, making the call a success.
Manner, Jukka
Thesis advisor
Tuominen, Antti
TETRA, SDN, OpenFlow, airbus DS TETRA, voice switching, group call
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