NXDN is an open standard protocol developed jointly by Kenwood and Icom. The protocol is branded as NEXEDGE by Kenwood and IDAS by Icom. Since the underlying protocol is the same, radios using NXDN, NEXEDGE, or IDAS can communicate with each other.

NXDN uses Frequency-Division, Multiple-Access (FDMA) technology, which separates communication streams by frequency, allowing simultaneous transmissions. It supports channels with bandwidths of 12.5 kHz or 6.25 kHz, providing flexibility for different applications.

This digital mode was initially designed for business and industry use but has also been adopted by public safety organizations. NXDN can transmit both voice and data but is not compatible with other digital modes such as P-25, DMR, TETRA, D-Star, or System Fusion. However, many NXDN-compatible devices support mixed-mode analog FM, allowing them to operate in analog and digital modes.

RAN (Random Access Number) is NXDN's equivalent to CTCSS encoding in analog systems. It unlocks the repeater's squelch when you transmit, allowing access to the repeater. There are 63 unique RAN codes available.

The NXDN protocol supports encryption. However, Amateur Radio Service rules may prohibit its use depending on your region. In the United States, encryption is expressly prohibited if the intent is to obscure communication.

NXDN repeaters can be listed on RepeaterBook, where the following details may be displayed on the repeater's detail page:

1. RAN Code
2. Bandwidth (12.5 kHz or 6.25 kHz)
3. Associated Network, if known

• Connecticut NXDN Amateur Radio Network
• NXManager
• NXDNINFO
• The Amateur’s Reference for NXDN