TEDS

TETRA Enhanced Data Service (TEDS) is an extension of the TETRA standard for professional mobile radio to provide a high speed data service. TEDS provides a packet data solution that can be integrated with existing TETRA systems. Integration is realised by the shared use of the control channel of an existing narrowband TETRA network. The combined network provides an integrated, backward comptabile solution for voice and data.

In TEDS up to 6 radio channels of 25 KHz can be combined for one data connection. Together with more efficiënt modulation techniques, data rates of 30 - 400 kbps are possible, depending on the number of radio channels chosen and the distance from the base station. The more efficiënt modulation techniques will not always be capable to provide coverage at the edge of a cell.

The agreed modulation schemes are:

• DQPSK for the common control channel,
• Q8PSK for early migration requiring a modest increase in speed,
• 4 QAM for efficient links at edge of coverage,
• 16 QAM for moderate data rates,
• 64 QAM for high data rates.

TETRA TEDS is developed mainly for the emergency services. It is expected that the TEDS equipment will be available in 2007. The equipment will most likely cover the 380-430 MHz range.