Narrow Band Emergency Messaging Software (NBEMS) is an Open Source software suite that
allows amateur radio operators to reliably send and receive data using nearly any computer
(Windows, Mac, and Linux) and any analog radio without requiring a dedicated digital
infrastructure or specialized modem hardware.
NBEMS uses the FLDIGI suite of software routines that emulate the hardware modem, compute
the error correction and format many standard message forms (to include ICS forms).
FLDIGI emulates many modems for different applications; we use the MT-63-2KL for UHF/VHF
messaging. NBEMS works with Windows, Linux and Mac computers and can be used on HF too.
There is even an Android app.
P25 Phase 1 - Widely deployed radio standard used in public safety and amateur radio.
ProVoice - EDACS Digital voice format used by public safety and amateur radio.
X2-TDMA - Two slot TDMA system currently being deployed by several public safety organizations. Based on the DMR standard with extensions for P25 style signaling.
DMR/MOTOTRBO - "Digital Mobile Radio" Eurpoean two slot TDMA standard. MOTOTRBO is a popular implementation of this standard.
NXDN - Digital radio standard used by NEXEDGE and IDAS brands. Supports both 9600 baud (12.5 kHz) and 4800 baud (6.25 kHz) digital voice.
D-STAR (AMBE Vocoder based)- Digital Smart Technologies for Amateur Radio developed by the
Japan Amateur Radio League (JARL) in the late 1990's.
P25 Phase 2 - This is not yet a published standard. Phase 2 will use a vocoder supported by mbelib.
OpenSKY - It is possible that the four slot version uses a vocoder supported by mbelib. The two slot version does not.
C4FM - Continuous envelope 2 or 4 level FSK with relatively sharp transitions between symbols. Used by most P25 systems.
GFSK - Continuous envelope 2 or 4 level FSK with a narrower Gaussian/"raised cosine" filter that affects transitions between symbols. Used by DMR/MOTOTRBO, NXDN and many others. Noisy C4FM signals may be detected as GFSK
QPSK - Quadrature Phase Shift Keying (and variants) used in some P25 systems and all known X2-TDMA
systems. May be advertised under the marketing term "LSM"
For Digital Voice (DV), there are four pieces of software that have been used for transmitting
digital voice on the amateur bands - WinDRM, DRMDV, FDMDV (AMBE Vocoder based), and FreeDV (Codec2 Vocoder based). WinDRM and DRMDV are based
on the DRM (Digital Radio Mondiale) system adapted for amateur use by Cesco HB9TLK.
FDMDV and FreeDV (Frequency Division Multiplexed Digital Voice) is a system devised by Peter Martinez
G3PLX of PSK31 fame. DRM and DRMDV signals are wider than FDMDV/FreeDV which is only 1.1kHz,
but they do incorporate a level of FEC (Forward Error Correction) whereas at the moment FDMDV/FreeDV
does not. Therefore, DRM and DRMDV require a more powerful computer than FDMDV and FreeDV.
Jared Szechy's DSD package is able to decode several digital voice formats from a discriminator tap audio and
synthesize the decoded speech. Speech synthesis (encoding) requires mbelib, which is a separate package.
Codec2 is an open source alternative which uses half of the bandwidth of AMBE to encode speech of similar quality, created by David Rowe and lobbied by Bruce Perens. Codec2 still continues to evolve, with additional "modes" being developed, refined and made available on a continuous basis. This has resulted in an open source codec that has progressively increased its robustness and performance – when subjected to some of the most challenging RF and acoustic environments.
FDMDV - Frequency Division Multiplex Digital Voice (AMBE Vocoder based)
FDMDV (Frequency Division Multiplex Digital Voice) is based on 15 carriers using
the 1400 LPC CODEC. High power in each carrier combined with a narrow 1.125 KHz
bandwidth provide good robustness with fast sync for a near SSB experience. FDMDV
is new and not derived from DRM technology.
DV4mini just acts as an Internet gateway (hotspot).
The Internet networks that it can access are various, and depend on the system used (eg C4FM Fusion),
but it can't directly go onto Yaesu's Wires-X network as their gateways (hotspots) are their own boxes that have to be individually subscribed to them.
The DV4mini can bridge networks, so for example I've had my DV4 mini on the FSC0001 network and talking to our 70cm repeater on the Wires-x network (as I'm near enough to the repeater).
Some others have permanently bridged networks using a similar technique.
There is also a version of the DV4mini with the AMBE chip piggybacked so you can use it with a microphone / speakers directly.
There are also lots of other products doing similar things - like openspot I think.
NANO-SPOT is a completely self-contained digital hotspot supporting DMR, Dstar, P25
and System Fusion communications. Fully assembled and tested in a ruggedized extruded
aluminum enclosure. All that's required for operation is a power source and a WiFi
based internet connection. Pi-Star Digital Voice Software pre-loaded and easily
upgraded via software.
This is the source code of ZUMspot/MMDVM_HS, personal hotspot (ADF7021 version of
the MMDVM firmware), based on Jonathan G4KLX's MMDVM software. This firmware supports
D-Star, DMR, System Fusion, P25 and NXDN digital modes.
This software is intended to be run on STM32F103 microcontroller. Also, Arduino with
3.3 V I/O (Arduino Due and Zero) and Teensy (3.1, 3.2, 3.5 or 3.6) are supported.
You can build this code using Arduino IDE with Roger Clark's STM32duino package, or
using command line tools with ARM GCC tools. The preferred method under Windows is
using STM32duino, and under Linux or macOS (command line) is using STM32F10X_Lib.
MMDVM May 8, 2017 ·
Ready to Ship the ZUMSpot Libre Kits by Bruce Given.
Has the ST Link and the Blue pills all programmed with Boot loaders and MMDVM code
so all you have to do is solder it together and plug it into a MMDVMhost...
Send a email email@example.com and we will get them out the door this week.
Pi-Star - A web Based Digital Voice Dashboard and Configuration Tool
Pi-Star is a web based digital voice dashboard and configuration tool written by
Andrew Taylor MW0MWZ, and in the format of a custom, pre-configured SD Card image
for the Raspbperry Pi and other ARM based single board computers.
Andy's web site is www.mw0mwz.co.uk
Pi-Star can be downloaded here:
C4FM-FUsion is a system developed by YAESU. It is based like DMR on 4FSK, and also
transmits 4 frequencies with a total data rate of 9600 bits/s. It uses the same AMBE+
Codec as DMR, but needs only 3600 bits/s. The extra bits are used in C4FM-Fusion in a
different ways. They can be used for data transfer (e.g. GPS) but also for additional
error correction to make the speech more stable during interference. There is also a
mode for high speech quality which uses all bits for speech only.
The Motorola DR3000 is a $5,000 repeater. It has trunking capabilities.
Motorola salesperson recommend looking at Hytera or even better a Vertex EVX-R70 at about $3000.
Apparently they are hard find them since Motorola has dominated the market.
Internally the system appears to have been made from two 70cm stock TYT Mobile radio units TH-9000D modified to become one RX and one TX. There is a custom built control mechanism which utilizes an ARM processor with two audio/digital processing chips. There is at present no way to change the firmware that controls the repeater. The Tytera TYT MD-8500 UHF 400-470MHz DMR Digital & Analog repeater is available from Aliexpress.
Tytera TYT MD-8500 UHF 400-470MHz DMR Digital and Analog Repeater
The suppliers is TYT:
Front View and internal views of the MD-8500 DMR Repeater consists of HR-9000D Radios and a Logic control box.
A reflector can be considered to be similar to a repeater, but with no RF capabilities.
Reflectors are Internet connected servers, generally in datacentres, which receive a
transmission from a connected gateway (via the Internet) and send it out to all other
connected gateways for retransmission, via RF in the case of a repeater. The term gateway
is used in the broader sense, which includes devices such as dongles and DVAPs
(See Diagram below).
The XLX AMBE is a server running on debian linux. It runs as a daemon service.
The software is available from github and operates on several network.
The XLX Multiprotocol Gateway Reflector Server
It requires apach2 web server, php, and g++.
The software looks pretty simple to install. The hardware hookup may be another matter.
Also would chew the bandwidth if it became a popular reflector.
The ports it uses tells a lot about it. Hopefully, it support transcoding between all protocols, though I seriously doubt it …
XLX Server requires the following ports to be open and forwarded properly for in- and outgoing network traffic:
TCP port 80 (http) optional TCP port 443 (https)
TCP port 8080 (RepNet) optional
UDP port 10001 (json interface XLX Core)
UDP port 10002 (XLX interlink)
TCP port 22 (ssh) optional TCP port 10022
UDP port 30001 (DExtra protocol)
UPD port 20001 (DPlus protocol)
UDP port 30051 (DCS protocol)
UDP port 8880 (DMR+ DMO mode)
UDP port 62030 (MMDVM protocol)
UDP port 10100 (AMBE controller port)
UDP port 10101 - 10199 (AMBE transcoding port)
The Brandmeister Reflector Network
BrandMaster/BrandMeister is an operating software for Master servers participating
in a worldwide infrastructure network of amateur radio digital voice systems.
BrandMeister allows you to connect to MOTOROLA DMR-MARC and Hytera DMRplus networks
this means you operate on both infrastructures the same time.
The CQ-UK group provide links to FM, C4FM, DMR and D-STAR to allows all modes to be able
communicate with the other in one place regardless of Repeater access or equipment owned.
Thanks to the hard work of MI5DAW Rickie, GM7KBK Ernie DMR C4FM and D-star can now
communicate together thru the CQ-UK room.
CQ UK's C4FM Fusion reflector is named CQ-UK and has a dtmf node id of (27793)
Rickie MI5DAW hosts an XLX925 reflector with extensive digitallinking from his home
here in Belfast and maintains a web site www.mi5daw.com
He has two modules going A and B and further plans to create more Modules and linking.
At the moment the xlx925 runs A module and xlx922/xlx925 run B module.
Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations. The purpose is to provide a reliable rapid method of calling and connecting during constantly changing HF ionospheric propagation, reception interference, and shared spectrum use of busy or congested HF channels.
A standalone ALE radio combines an HF SSB radio transceiver with an internal microprocessor and MFSK modem.
Echolink requires 5200/tcp, 5198/udp, and 5199/udp ports to be open.
The application test shows that they fail but this appears to be a false report
as the application works well despite the reported errors. This maybe a result of
running the application ion wine emulation on Ubuntu Linux.
The terms to describe a ports state are confusing. Here is a summary of their meanings:
Listening means that the port isn't protected by a firewall or the firewall allows inbound traffic
to there and that there is a service listening on that port
Filtered means that there may be or may not be a service listening to that port but the firewall
is denying inbound traffic
Closed means that the port isn't protected by the firewall and but there is no service/application
listening on that port
Open means it is available to the outside with a service application is listening.
If it isn't, it will show as "closed" on nmap scans.
The "netstat -atnp" command does not show 5200, 5298, 5199 ports as open.
The nmap command shows the ports as closed.
The command "nc -l port-no" will run a "service" on the port and as there is now a
service "listening" on the port an nmap scan should show the port as open.
Opening the ports required for Echolink to operate is one issue, but a far bigger issue appears
to be obtaining a reliabale proxy server.
Echolink worked fine this morning, 9th April 2018, on both the Laptop and the Android phone.
Now, four hours later neither will connect! Still using the Optus Hauwei E5186s-61a wireless modem.
The log on the Laptop shows "2018-04-09 12:51:23 ConnectAttemptFailed VK4RBS-R 18.104.22.168 Timed out."
This is setup image from Laptop.
I suspect the proxy servers are failing intermittently, so I changed the setting
on the laptop to this and it all works again. (Selected the proxy at random form the list.)
Address type IPv4
ASN 47610 - RWTH-AS
Organization RWTH Aachen University
Maybe this proxy server was not responding.
Qtel- a native Linux Echolink Application
Qtel, the Qt EchoLink client, is a graphical application used to access the EchoLink network.
and is available from www.svxlink.org.
It can be install with the linuc "apt" utility by typing the following command at the terminal.
At this point I can run Qtel but cannot get a connection.
Advanced repeater controller and EchoLink software for Linux including a GUI, Qtel - The Qt EchoLink client