Next Generation Digital Narrowband (NXDN)

Next Generation Digital Narrowband (NXDN)

Frequencies	136 MHz,174 MHz,400 MHz,520 MHz
Frequency Range	136 MHz - 520 MHz
Mode	NFM
Modulation	4FSK
ACF	80 ms
Emission Designator	—
Bandwidth	6.25 kHz,12.5 kHz
Location	Worldwide
Short Description	NXDN is a digital narrowband trunked radio protocol used in commercial, business & industry, transport and Public Safety professional radio systems.
I/Q Raw Recording	Download file
Audio Sample

NXDN is a digital narrowband trunked radio protocol developed by ICOM Inc. and JVCKENWOOD Co. The NXDN protocol is used in commercial, business & industry, transport and Public Safety professional radio systems. NXDN has recently been recognized by the ITU as an international digital radio communications standard.

NXDN uses FDMAFrequency Division Multiple Access, and a NXDN channel be either 12.5 kHzKiloHertz (kHz) 10^3 Hz or 6.25 kHzKiloHertz (kHz) 10^3 Hz wide. 6.25 kHzKiloHertz (kHz) 10^3 Hz dual-channel systems can be configured to fit within a 12.5 kHzKiloHertz (kHz) 10^3 Hz channel. This effectively doubles the spectrum efficiency compared to an analog NFMNarrowband Frequency Modulation system occupying a 12.5 kHzKiloHertz (kHz) 10^3 Hz channel. The architecture of NXDN is such that two NXDN channels, within a 12.5 kHzKiloHertz (kHz) 10^3 Hz channel for example, can be allocated as voice/voice, voice/data, or data/data.

Kenwood's brand for NXDN equipment is "NEXEDGE", while Icom's brand for NXDN equipment is "IDAS", or Icom Digital Advanced System.

Characteristics

There are two main modes, NXDN96 and NXDN48.

Characteristics	NXDN48	NXDN96
Bandwidth	6.25 kHzKiloHertz (kHz) 10^3 Hz	12.5 kHzKiloHertz (kHz) 10^3 Hz
Symbol Rate	2400 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.	4800 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.
Data Rate	4800 bpsBits per second (bps)	9600 bpsBits per second (bps)
FDMAFrequency Division Multiple Access Channels	2 Per 12.5 kHzKiloHertz (kHz) 10^3 Hz Channel	1 Per 12.5 kHzKiloHertz (kHz) 10^3 Hz Channel
Speech Codec Rate	3600 bpsBits per second (bps)	3600 bpsBits per second (bps) (7200 bpsBits per second (bps) option)
4FSK4-Level Frequency Shift Keying Frequency Deviation	NXDN48 ± 116.7 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., ± 350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	NXDN96 ± 350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., ± 1050 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).

Samples

NXDN48	NXDN96

Additional Samples

NXDN Idle Channel

NXDN48 Trunking Channel:

Analog FMFrequency Modulation Voice vs NXDN Digital Voice

NXDN96

Trunking Signal Sample:

Signal with Digital Voice:

Decoded Audio:

Frequencies

VHFVery High Frequency (30-300 MHz) (136-174 MHzMegaHertz (MHz) 10^6 Hz) and UHFUltra High Frequency (300-3000 MHz) (400-520 MHzMegaHertz (MHz) 10^6 Hz) bands.

Video Examples

• Raw NXDN trunking control channel sound
• DSDPlus NEXEDGE Trunk Following
• DSD+ Decoding NXDN
• Christian Co NXDN

Decoding Software

Hobby Level Software

• Unitrunker
• DSDPlus

Professional Software

• go2DECODE
• go2MONITOR
• Rohde&Schwarz CA100

Decoding Tutorials

• Following trunked radio with the RTL-SDR

Additional Links

• RadioScanner.RU NEXEDGE
• RadioReference.com NEXEDGE
• WAVECOM Database: NXDN
• shoc Database: NXDN
• Wikipedia NXDN
• NXDN White Paper
• Kenwood NXDN Radios
• NXDN news ITU recognition

Additional Images

This is an idling NXDN48 signal reported on 19 September 2015‎ in Austria at 447.135 MHzMegaHertz (MHz) 10^6 Hz used by The "Kunsthalle" Vienna. It was reported with its counterpart at 447.350 MHzMegaHertz (MHz) 10^6 Hz, which is a NXDN96 signal, used by the Vienna Schatzkammer