Direct mode is useful for a group of people who need a dedicated speech channel for a particular task, for example fire fighters or security services performing a special duty. In remote areas outside the coverage of the TETRA network, or in areas of poor coverage, for example in tunnels, direct mode is the only way to maintain communication at the incident site.
"Nokia is proud of the achievement of earning this certificate for the TETRA direct mode operation. We have the Nokia THR420 already in the market, and the direct mode operation is one of the key benefits of TETRA. Our customers can be assured that our products fully meet the TETRA specifications. We are continuing to develop TETRA terminals to meet the expectations of the most demanding professional customers," said Hannu Huttunen, Vice President, Special Products, Nokia Mobile Phones.
With the Nokia THR420, switching between the two operation modes is carried out easily either from the menu or by dedicating one key for switching between them. When switched to direct mode (DMO), the radio unit shows the message 'direct mode' on the display. The user can now choose a DMO channel using a rotary control knob and the selected channel is shown on the radio's display.
In direct mode, everybody using the same channel and having the same group address can take part in the conversation. When receiving in direct mode, the identity as well as the signal strength of the transmitting party are shown on the radio's display. The Nokia THR420 has a capacity of 40 DMO channels, and open group and open network addressing are also supported. Other DMO features of the Nokia THR420 include late entry and trunked mode emergency call.
Nokia is paving the way to the mobile information society with its innovative products and solutions. The company is the leading mobile phone supplier and a leading supplier of mobile, fixed and IP networks, related services as well as multimedia terminals. In 1999, Nokia's net sales totaled EUR 19.8 billion (USD 19.9 billion). Headquartered in Finland, Nokia is listed on the New York (NOK), Helsinki, Stockholm, London, Frankfurt and Paris stock exchanges and employs more than 55 000 people.