Glossary¶
Code Plug¶
While somewhat generically used for digital radio and even FM VHF and UHF radios, people who talk about DMR radios especially throw the term CPS about it like it’s salt.
Radios used crystals to control the frequencies, and sometimes, users applied internal jumpers for the various options. Later, builders moved the internal jumpers to a jack on the back of the radio. A “plug” with wire jumpers plugged into the jack enabled these options. These became the original code plugs. Later, builders and manufacturers controlled more things using these code plugs, such as tone encode/decode selection.
Later, as radios became microprocessor-controlled, the external code plugs moved inside the radio as programmed information. The term has, unfortunately, remained with us. The code plug contains the operating frequencies, tone selections, timeout values, system IDs, etc. In some instances, some parts of the radio definition itself are in the code plug. These days, the code plug is just a relatively small file transferred to the radio with Code Plug Software.
D-Star¶
Digital Smart Technologies for Amateur Radio A digital voice and data protocol specification for Amateur Radio by the Japan Amateur Radio League published in 2001. D-Star implements GFSK modulation in a 6kHz wide channel.
DMR¶
Digital Mobile Radio An ETSI standard digital radio specification for professional, commercial, and private radio users published in 2005. Implements 4-level FSK modulation in a 12.5kHz wide channel using TDMA, effectively ‘doubling’ channel capacity.
Dynamic Talkgroup/Reflector¶
A talkgroup or reflector that is not commanded by the WPSD configuration to be monitored on the Internet. Often one is enabled by the implicit or explicit commands from the RF link.
ETSI¶
European Telecommunications Standards Institute The European Telecommunications Standards Institute is an independent, not-for-profit, standardization organization in the field of information and communications.
FSK¶
Frequency-shift keying Frequency-shift keying is a frequency modulation scheme in which digital information is encoded on a carrier signal by periodically shifting the frequency of the carrier between several discrete frequencies.
GFSK¶
Gaussian frequency-shift keying Rather than directly modulating the frequency with the digital data symbols, “instantaneously” changing the frequency at the beginning of each symbol period, Gaussian frequency-shift keying filters the data pulses with a Gaussian filter to make the transitions smoother.
Hotspot¶
An SBC flashed with a hotspot image (for example, WPSD), with either a simplex or duplex hotspot board (HAT) connected to the Internet. Hotspots usually have radios built in, typically with an ADF7021 RF chip and one or two SMA antenna connectors or an onboard ceramic antenna.
MMDVM¶
Multi-Mode Digital Voice Modem MMDVM hardware and software are at the core of most digital mode hotspots on the market. The success of the MMDVM Project comes from different people and projects going back to the earliest days on D-STAR. MMDVM now supports D-STAR, DMR, YSF, P25, NXDN, POCSAG, and analog.
Node¶
A simplex hotspot, using an MMDVM modem board and an external radio. The modem board does not include an RF chip and typically connects to a higher-power mobile radio.
NXDN¶
Next Generation Digital Narrowband A digital voice and data radio protocol developed jointly by Icom and Kenwood for public land mobile radio systems, published in 2005. NXDN implements 4-level FSK modulation in either a 12.5kHz or 6.25kHz wide channel.
P25¶
Project 25 Also known as APCO-25, is a set of digital voice and data radio protocols developed by public safety professionals starting in 1989. Implements C4FM 4-level FSK in a 12.5kHz wide channel (Phase I).
Repeater¶
A duplex hotspot, using an MMDVM modem board and two external radios or attached to a repeater or repeater controller. The modem board does not include an RF chip and typically connects to an existing repeater or repeater controller.
SBC¶
A single-board computer A common example of an SBC is the ubiquitous Raspberry Pi.
Static Talkgroup/Reflector¶
A talkgroup or reflector configured by the user in WPSD and constantly monitored for incoming traffic from the Internet. When traffic is received, WPSD passes one of the active talkgroups over the RF link. This acts similiar to a scan list in some radios.
WPSD¶
“WPSD Plausibly Stands for Divergence”
WPSD is the name of the software suite and project.
Hint
WPSD = WPSD Plausibly Stands for Divergence
YSF¶
Yaesu System Fusion A digital voice and data protocol specification developed by Yaesu for Amateur Radio in 2013. Implements C4FM 4-level FSK in a 16kHz wide channel.