One of the most essential issues in radio communications is spectrum efficiency. Although the basic composition and usage of bandwidth are different among NXDN and DMR air interfaces, both offer excellent spectrum efficiency with real narrow-banding: the NXDN air interface can fit into the very narrow 6.25 kHz bandwidth using FDMA technology. DMR, on the other hand, employs two-slot TDMA to fit 2 talk paths within the existing 12.5 kHz bandwidth, realizing “6.25kHz equivalency” without requiring additional investment. KENWOOD thus offers a wide variety of CAIs and equipment so that users can comply with regulatory requirements while satisfying their own needs and enjoying system configuration convenience.

The KENWOOD brand represents many decades of experience in the production of high-end equipment for audiophiles, so our radios offer standout sound quality. Specifically, all KENWOOD professional radios benefit from our audio specialist expertise in sound analysis and noise reduction, which in turn enable optimization. As a result, you can be confident of clear exchanges even in challenging environments and conditions.

In an emergency or whenever a user needs to interrupt a call, Call Interruption featured on DMR CAI is available in both direct and repeater modes, while encoding or decoding.

Up to two simultaneous subscriber calls can be supported in the DMR’s 12.5 kHz channel without requiring a base station or repeater.

NXDN trunked system traffic channels can be shared with existing external analog conventional or analog trunked logic controllers, extending service to analog fleets as they transition to NXDN trunking.

For demanding mission/operation-critical users, it is essential to have a system that offers top-notch security 24/7. And they can put their full trust in the NXDN Gen2 system, not least because one can assign a secured priority channel to a specific TCH – for a group, console, or other peripheral. Members of such a group will have access at all times – ideal for public safety applications. As well as enabling private system applications, this facilitates the development of new solutions – for example, using a Secured Priority Channel for SMR network channel leasing to end users.

Supervisors and console operators – for example, in airport control towers and taxi dispatch centers – will certainly welcome this feature, which ensures that console calls have priority. If there is no traffic channel available, the console can take over a channel: radios in operation will automatically stop ongoing call transmission/reception, and the console will be able to communicate directly with their users. Call interruption enables emergency alerts or instructions to be issued, making this ideal for public safety/works applications.

KENWOOD offers dispatch application software such as KAS-20 that integrates with a number of different systems from a single standalone system to multi-client system with a server PC as well as via VPN connection.

Connected to a Digital trunked system, the KTI-4 Telephone Interconnect Adapter converts analog voice to/from digital, enabling two-way communication between a telephone and a radio. It connects to an analog PABX/PSTN system through analog telephone patch equipment such as the Zetron Model 735 and Zetron Model 30 (availability varies by region).

As RF signal strength weakens with distance, analog reception becomes increasingly noisy and intermittent. The low BER of NXDN improves reception in fringe areas, thereby effectively increasing range by as much as 20% over FM analog, resulting in a 50% increase in coverage area for digital 6.25 kHz.

Furthermore, even compared to digital 12.5 kHz bandwidth operation such as DMR, the narrower 6.25 kHz bandwidth enabled by the FDMA technology of NXDN extends range by 15%. Receiver filters are narrower and can thus reduce noise. The net result is superior clarity over a 30% wider coverage area.

Sound quality comparison between digital and analog transceivers

As part of the development process, KENWOOD radios have to prove they can survive the most grueling conditions. They are dropped, soaked, splashed and subjected to extremes of temperature. Also the keys are operated tens of thousands of times to ensure they can withstand heavy use over a period of several years.