Plain-English definitions of the terms used across the N6JET Digital Voice Guides.
AllStarLink — An internet network that links analog FM repeaters and nodes worldwide over VoIP, so distant machines act as one system. It runs the app_rpt software (by Jim Dixon, WB6NIL) on the Asterisk PBX; the current generation is ASL3 (AllStarLink 3).
AMBE — The original proprietary voice codec, used by D-STAR. It needs a licensed chip or paid software.
AMBE+2 — The newer proprietary voice codec shared by DMR, Fusion, and NXDN — which is why those three bridge to one another without re-encoding the audio.
AMBEserver — Small software that shares a hardware AMBE dongle over the network, so other programs can borrow it for transcoding.
AMS — Automatic Mode Select: a Yaesu Fusion feature that listens to an incoming signal, recognizes whether it is analog or digital, and switches the radio to match.
Analog_Bridge / MMDVM_Bridge — The two DVSwitch programs that convert between a mode's digital stream and plain audio — the pieces that make cross-mode bridges possible.
APCO — The Association of Public-Safety Communications Officials, whose “Project 25” standard became P25.
Auto-static — On a simplex hotspot, a talk group linked so that it stays connected and does not time out, even with no activity — static-like behaviour arranged from the hotspot rather than in SelfCare.
BrandMeister — One of the largest worldwide DMR networks, and one of the two networks this guide connects your hotspot to.
C4FM — Continuous 4-level FM: the 4-level FSK modulation Yaesu System Fusion uses, and a common name for the mode itself.
Callsign — Your unique, FCC-assigned identifier as a licensed ham (for example, N6JET). You use it on the air and when registering for DMR services.
Callsign routing — D-STAR's way of addressing a call by the destination's callsign (or CQCQCQ for an ordinary call) instead of by a number or talkgroup.
CAN — Channel Access Number (0–15): M17's access code, the digital equivalent of a PL tone.
CCS7 — A single cross-mode identifier (7 digits for users, 6 for repeaters) that works across DMR, D-STAR, P25, NXDN, and more, built on the same Mobile Country Code numbering as a DMR ID.
Channel — A single entry in your radio's memory, set to one talk group. You switch channels to switch talk groups.
Cluster — A group of repeaters linked together on BrandMeister (talk group 2), so a call reaches every repeater in the group — often the machines of one club — but goes no further.
Code plug — The complete set of programming inside your radio — its channels, zones, talk groups, and settings. You build it on the computer and write it to the radio.
Codec 2 — An open-source, royalty-free voice codec (by David Rowe, VK5DGR) used by M17. It runs in plain software with no special chip.
Color code — A number from 0 to 15 that acts like a DMR “lock.” Your radio and your hotspot must use the same color code to talk to each other — think of it like a CTCSS/PL tone in the analog world.
CPS — Customer Programming Software: the manufacturer's program (here, AnyTone's) you use on a PC to build your code plug and write it to the radio.
Crossmode — A bridge that connects one digital mode to a different one, so radios on separate modes can reach each other. Examples on this site include DMR2NXDN, DMR2YSF, and DMR2XLX, which let a DMR radio talk to NXDN, Fusion (YSF), and XLX.
CTCSS / PL — Continuous Tone-Coded Squelch System, also called a “PL tone”: the sub-audible tone that gates an analog FM repeater. The digital modes' access codes (color code, RAN, CAN, NAC, DG-ID) do the same job.
D-STAR — The first digital voice mode designed for amateur radio (developed by JARL, built by Icom). It uses GMSK modulation and routes calls by callsign rather than by numbers.
Dashboard — The web page (the WPSD interface) you open in a browser to see and control your hotspot.
DG-ID — Digital Group ID (0–99): Yaesu Fusion's access code, which also selects which linked room or reflector a repeater connects to.
Dial-a-TG — A way to bring up a talk group on demand: with talk group 9 on time slot 2, you send a Private Call to the talk group number to link it, then talk through TG 9.
DMR — Digital Mobile Radio: an ETSI digital standard and the most popular digital voice mode on the ham bands. It uses two-slot TDMA, the AMBE+2 vocoder, and a color code for access.
DMR Gateway — Software in the hotspot that lets it connect to several DMR networks at once and route each talk group to the right one. It's what makes two networks (and the crossmodes) work together.
DMR ID — A unique number (usually 7 digits) tied to you and your callsign. Every DMR network uses it to identify who's talking. Free from radioid.net.
DMR network — A worldwide system of internet-linked DMR servers, repeaters, and hotspots. BrandMeister and TGIF are two such networks.
DMR+ — A DMR network family built on IPSC2 master servers, tied together worldwide through a shared bMaster+ backbone. It interconnects with DMR-MARC and other DMR networks.
DMR-MARC — One of the original amateur DMR networks (the Motorola Amateur Radio Club), and the group that first ran the DMR ID database before radioid.net.
DVSwitch — A suite of open-source programs (Analog_Bridge, MMDVM_Bridge, and friends) that bridges digital modes to one another and to analog systems.
Dynamic talk group — A talk group you switch on by keying it up; it stays linked while there is activity, then drops on its own after about 15 minutes of quiet. (Compare Static talk group.)
EchoLink — A long-running internet linking system that connects analog stations, including from a computer or phone app.
ESSID — Extra digits added to the end of your DMR ID so you can run more than one hotspot or device on the same ID without conflict. (Not the same as a WiFi SSID.)
ETSI — The European Telecommunications Standards Institute, which publishes the DMR standard.
FCS — A family of Yaesu Fusion reflectors, addressed by a number and a room.
FDMA — Frequency-Division Multiple Access: each conversation gets its own slice of frequency. NXDN and Fusion work this way. (Compare TDMA.)
FICH — Frame Information Channel: the part of a Fusion (C4FM) transmission that tells the receiver which mode and settings are in use.
FRN — FCC Registration Number: your account number with the FCC, used to log in and download your official license.
FSK / 4FSK — Frequency-Shift Keying: sending digital data by shifting the transmit frequency. The 4-level form (4FSK) carries the voice for DMR, C4FM, NXDN, P25, and M17.
GMSK — Gaussian Minimum Shift Keying: the smooth two-level modulation D-STAR uses — the one ham digital mode that is not 4-level FSK.
HBlink (HBlink3) — Open-source server software that ties DMR hotspots and repeaters together — a build-it-yourself DMR network core.
Hotspot — The small device in your home that links your radio to DMR networks over the internet — your own personal, low-power gateway.
Hotspot security password — A personal password you set in BrandMeister SelfCare so no one else can connect using your DMR ID. You choose this one.
IMBE — The voice codec used by P25 Phase 1 (an older relative of the AMBE family).
IMRS — Internet-linked Multi-site Repeater System: Yaesu’s own way of linking Fusion (DR-2X) repeaters directly to one another over the internet — no PC or hotspot required — routed by DG-ID. Separate from Wires-X and the open YSF reflectors.
IPSC2 — A widely used DMR server program (IP Site Connect 2) that runs several DMR networks.
JARL — The Japan Amateur Radio League, which developed D-STAR.
M17 — A fully open-source digital voice mode built by hams, using the open Codec 2 vocoder instead of a proprietary one — no license fees, nothing closed inside.
MCC — Mobile Country Code: the three-digit ITU country code that forms the front of every DMR Radio ID (310–329 for the USA).
MMDVM — Multi-Mode Digital Voice Modem: the board inside the hotspot that does the actual radio work. WPSD is the software that runs it.
Module — A “room” within a reflector, labeled with a letter (A–Z). Different modules on the same reflector carry separate conversations.
mrefd — The reflector server software for M17, which divides each reflector into lettered modules.
NAC — Network Access Code: P25's access code, its version of a PL tone.
NEXEDGE / IDAS — Kenwood's (NEXEDGE) and Icom's (IDAS) brand names for NXDN. Both are the same protocol and work together.
NXDN — A narrowband digital voice mode developed by Icom and Kenwood. It uses FDMA and the AMBE+2 vocoder, fitting a conversation into as little as 6.25 kHz. Reachable from DMR through the DMR2NXDN crossmode.
P25 — Project 25 (APCO-25): a public-safety digital standard that some hams use. Phase 1 uses the IMBE vocoder; Phase 2 uses AMBE+2.
Padded talkgroup — A talkgroup entered with an extra prefix digit in front, so DMR Gateway can tell which of several networks you meant. The gateway strips the prefix before forwarding, so the network itself sees the plain number — TGIF 101 on prefix 5 is dialled as 5000101.
Parrot — A test service that records your transmission and plays it right back, so you can confirm your hotspot is working and hear how you sound.
Peanut — A smartphone and PC app (by David, PA7LIM) that lets licensed hams reach D-STAR, DMR, and Fusion rooms over the internet, without a radio or hotspot.
Pi-Star — Popular ready-made hotspot and repeater software for the Raspberry Pi. It runs MMDVM and supports all the digital modes; WPSD grew out of it. See Pi-Star and WPSD.
RAN — Radio Access Number (0–63): NXDN's access code, the digital equivalent of a PL tone.
Raspberry Pi — The small single-board computer the hotspot runs on. WPSD is written to its SD card.
REF / XRF / DCS — The three older D-STAR reflector families, each from a different piece of software (REF = DPlus, XRF = DExtra, and DCS).
Reflector — A “meeting room” that links many hotspots and repeaters together so everyone connected hears the same conversation. XLX is a type of reflector.
Rewrite rule — A line in DMRGateway.ini that alters a call as it passes through. TGRewrite maps a padded talkgroup range onto the real one, PCRewrite does the same for private calls, and SrcRewrite puts the prefix back on traffic returning from the network.
RX group (Receive Group List) — A list in your code plug of which talk groups a channel will receive. It controls what you actually hear on a given channel.
Security key — A long code that TGIF generates for you (you don't pick it). Your hotspot uses it to connect to TGIF as you.
SelfCare — The web portal of a DMR network (BrandMeister and TGIF each have their own) where you register your DMR ID, set your hotspot security password, and choose your static talk groups.
SSID — The name of a WiFi network. One of the four things you supply so the hotspot can join your WiFi. (Not the same as the radio's ESSID.)
Static talk group — A talk group permanently linked to a time slot, so it is always connected and you always hear it; on BrandMeister you set these in SelfCare and can hold several on one slot. (Compare Dynamic talk group.)
SVXLink — Open-source repeater-controller and linking software, often used to bridge analog and digital systems.
TAC — Tactical talk groups (310–319 in the US) for moving a conversation off a busy calling channel; on BrandMeister they are dynamic-only — they cannot be made static and always time out, which keeps them clear for the next users.
Talk group — A channel of conversation on a DMR network, identified by a number (for example, 91 = Worldwide). Pick a talk group and you join everyone talking on it.
TDMA — Time-Division Multiple Access: one channel split into two time slots so two conversations share it. DMR works this way. (Compare FDMA.)
TG — Shorthand for “talkgroup.”
TGIF — Another worldwide DMR network — the second one this guide connects your hotspot to. Known for easy talk group switching.
ThumbDV / DVStick — USB dongles containing an AMBE chip, used to encode, decode, or transcode AMBE voice in software setups. See Transcoding Explained.
Tier I / II / III — The three DMR service levels. Amateurs use Tier II (conventional, two-slot); Tier III adds trunking.
Time slot — DMR splits one channel into two simultaneous “lanes” called time slots (1 and 2). Most hotspots use slot 2.
Transcoding — Decoding the voice from one mode's codec and re-encoding it into another's, so modes with different codecs (D-STAR, M17) can reach the AMBE+2 modes. See Transcoding Explained.
UR / RPT1 / RPT2 / MY — The four D-STAR callsign fields: who you are (MY), the local repeater and its gateway (RPT1, RPT2), and where the call should go (UR).
URF — A modern multi-protocol reflector (the successor to XLX) that can link and transcode several modes at once. See Transcoding Explained.
USRP — In DVSwitch, the simple audio link that passes voice between its software pieces (named after the Universal Software Radio Peripheral interface it borrows).
Vocoder — The software or chip that compresses your voice into the small digital stream a mode sends, and expands it back into audio at the far end. See AMBE and Codec2.
VoIP (SIP) — Voice over IP: carrying voice as data across the internet. SIP (Session Initiation Protocol) is the common standard for setting up those calls; ham VoIP services such as FreeSTAR Everywhere, Hams Over IP, and AmateurWire use it to link operators by “phone.”
Wires-X — Yaesu's own internet-linking system for Fusion, organized into rooms and nodes (separate from the open YSF reflectors).
WPSD — The hotspot software this guide uses (originally “W0CHP-PiStar-Dash”). It runs the hotspot and provides the dashboard. See Pi-Star and WPSD.
XLX — A multi-mode reflector system that links D-STAR, DMR, Fusion, and M17 and can transcode between them. A DMR radio reaches it through the DMR2XLX crossmode.
YCS — YSF Cluster Server: a smarter kind of Fusion reflector that groups rooms and routes by DG-ID.
YSF (System Fusion) — Yaesu's digital voice mode, using C4FM modulation and the AMBE+2 vocoder; the name YSF also refers to its open reflector system. Reachable from DMR through the DMR2YSF crossmode.
Zone — A folder of channels in your radio, used to keep things organized (for example, a BrandMeister zone and a TGIF zone). You pick a zone, then a channel within it.