Facilitating Expansion

Up to 100 consoles can link to a single IP gateway (using KPG-1002GW gateway software), so a single network can connect a maximum of 1,000 consoles. Call recording and logging interfaces are available.

Yet another example of the flexibility of an NXDN Gen2 system is that it is SNMP-compatible throughout the network. An improved IP interface and system architecture facilitate access for vendors, offering an easy handshake even with third-party solutions. This makes customizing relatively simple, enabling for example two-way connectivity with public safety networks.

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, 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.

NXDN Type-D Trunking is the FB6*-based digital LTR protocol specified by the NXDN Forum. Unlike Type-C trunking, there is no dedicated control channel: trunking is under the control of the home repeater assigned to each radio. And like LTR, there is no registration.
Also, Slot Select Trunking and Simplified Trunking will be available in future to enable more cost-effective DMR single-site trunking.

FCC Station Class Codes

The NXDN Type-C trunking provides increased capacity, enhanced call capabilities, improved security and faster communications with less user interaction than conventional systems. The system automatically assigns channels for faster, efficient use of spectrum, allowing users to concentrate on the job at hand.

• System Call Queuing: Stacks call requests and processes calls when a channel becomes available. System operators can assign higher queue priority to certain users and pre-empt lower priority users for more important dispatch and emergency calls.
• Priority Monitor: Monitors for up to 4 high priority talk groups and automatically switches radios to a higher priority call, such as from a dispatcher or supervisor.
• Privacy: Group and individual calls enjoy complete privacy as other users in the system cannot monitor the calls.
• Late Entry: Subscriber units may join a group or individual call already in progress after powering on or upon entering the system coverage area.
• Message Trunking: Users are granted a traffic channel for the length of a two-way call to reduce interruptions by utilizing less system resources.
• Transmission Trunking: Users are granted a traffic channel only during each push-to-talk, optimizing channel resources during peak traffic hours.

GPS is an ideal way to track the position of personnel and vehicles. And Gen2 further enhances this convenience to facilitate management. The System Controller is aware at all times how many GPS-equipped SUs are on duty, and when a new SU is registered, it is assigned a reporting frame and traffic channel (not the CCH, as before).

Also, improvements to the air protocol minimize data overhead, thus maximizing traffic/data capacity while reducing GPS data processing time. Organizations that depend on GPS, such as utility companies, will be able to reap maximum benefit from these enhancements.