When Kenwood introduced its NEXEDGE® range of advanced digital two-way radios in 2008 it was the first system to offer both Mixed Mode (the ability to communicate with both analogue and digital handsets automatically, without manual switching) and trunked radio communication capability.

Built on the solid foundations of over 30 years success in the design and manufacture of analogue radios, Kenwood NEXEDGE® equipment employs state of the art digital voice processing technology to ensure clear voice quality and reliability, even in the noisiest of environments and digital encryption to allow for complete protection against casual eavesdropping.

All NEXEDGE® equipment can communicate with existing analogue radios, either terminal to terminal, as a system, or even as a multi-site trunked network. This provides a cost effective and controlled solution to customers migrating from an analogue system to the proven advantages of digital.

Winner of the Innovation in Business Radio Award at the 2010 Federation of Communications Services AGM, NEXEDGE® has been designed to deliver the safety, security, efficiency, performance and future-proofing that the market demands from leading edge digital two-way radio communications.

Spectrum Efficient: All NEXEDGE® equipment operates in 25 & 12.5 kHz analogue and 12.5 & 6.25 kHz NXDN® digital modes – satisfying spectrum requirements today & tomorrow.

Migration by Design:NEXEDGE® extends the life of current radio system assets. All NXDN® digital modes use the same Class-C power amplifiers and site management equipment used for current analogue stations, ensuring return on investment (ROI) and a multitude of supplier choices. Current analogue and NXDN® digital fleets can share a NEXEDGE® base/repeater station in 12.5 kHz conventional "Mixed Mode," thus providing uninterrupted service as long as needed and a straightforward migration path as aging analogue fleets are replaced with digital. Also, NEXEDGE® trunked traffic channels can be shared with existing external analogue conventional or trunked logic controllers, extending service to fleets as a transition to NXDN® trunking is underway.

Variety of Operation:NEXEDGE® systems are configurable in traditional conventional, trunked and wide area trunked network operation modes. IP connectivity for NEXEDGE® trunked sites provides scalability over existing LAN/WAN assets and services.

Outstanding Voice Quality:The AMBE+2™ Vocoder is a state-of-the-art voice compression digitization technology that offers superior clarity at varying signal strengths, even at highway speeds.

Secure Privacy:NEXEDGE® technology offers inherent security against casual electronic eavesdropping via its NXDN® digital air interface. It also includes NXDN® voice & data scrambling for security against external threats while providing confidentiality within the same system and talk group. Inter-network links are further secured through encrypted VPN tunneling. Also NEXEDGE® multi-site network operators can automatically validate individual subscriber radio hardware by ESN (a unique factory-embedded Electronic Serial Number ) rather than changing the system's unit and group ID lists in the event a unit is lost, stolen, or removed permanently or temporarily from service.

The NXDN® Digital Advantage

In analogue systems as the signal strength decreases in low-coverage areas, noise and dropouts increase, severely degrading intelligibility. However, with the NXDN® digital system, which features enhanced Forward Error Correction (FEC), the digitized audio stream is less susceptible to noise, resulting in superior clarity at varying signal strengths. System operators converting from analogue to NEXEDGE® typically comment that users now receive calls in areas that were out of range before. NXDN® reduces lost or misinterpreted calls and the need for repeat calls, thus enhancing workforce productivity.

NXDN®

A key element of the NXDN® air interface is the AMBE+2™ vocoder which digitises speech while retaining natural voice nuances, performs noise reduction, introduces FEC and compresses this voice data to accommodate land mobile radio data rates. Next, the radio's digital signal processor (DSP) protocol- packages the vocoder, signaling, control, and more FEC data together and converts this to a uniquely filtered 4-Level FSK digital waveform that modulates the transmitter. This results in an unusually low bit-error-rate digital air interface delivering robust communications even in weak signal strength areas. The NXDN® air interface is capable of fitting into both narrow 12.5 kHz and very narrow 6.25 kHz bandwidth channels meeting the tightest of spectrum efficiency requirements (9600 bps @ 8.3 kHz and 4800 bps @ 4 kHz occupied bandwidth respectively). NXDN® is a Frequency Division Multiple Access (FDMA) methodology whereby one user accesses a channel frequency at any one point in time (i.e. accesses via the frequency domain). Other digital methods such as Time Division Multiple Access (TDMA) permit more than one user to access the channel frequency via timeslots (i.e. accesses via the time domain), but there has to be a tradeoff between coverage and effective transmission rate, as increasing the former means decreasing the latter.