Ham VHF/UHF Digital Voice Modes. For the beginner

Transcription

1 Ham VHF/UHF Digital Voice Modes For the beginner

2 Reminder about some terms from the 1 st presentation on HF digital modes When looking at the digital modes of today, you have to look at it from two perspectives Encoding (how 1 s and 0 s are encoded onto the carrier wave) Frame Format (how the data is formatted to mean something) One character at a time or A group of characters packed together as one unit

3 Summary of Encoding Techniques (from HF Digital Modes Presentation) On/Off Keying; dots/dashes AM/FM/SSB (no frame format since there re no 1 s and 0 s) FSK/MFSK (Frequency Shift Keying or Multiple Frequency Shift Keying) PSK (Phase Shift Keying) (Binary and Quadrature) PTCM (Pragmatic Trellis Coded Modulation) PSM (Phase Shift Modulation) (Modulating the phase of the carrier wave with the signal) *Some sound diddly ; some sound chirpy ; some sound musical on HF *At VHF, higher data rates are allowed, so they begin to sound like static, screechy, or scratchy

4 Summary of Frame Formats (from HF Digital Modes Presentation) Single Character Morse Code 5-bit Baudot 6, 7 or 8-bit ASCII (with or without Huffman compression at this layer, error correction code) Varicode (with or without Huffman compression at this layer, error correction code) Base128 Grouped Characters APRS protocol State Oriented (as apposed to request/response) WinLink

5 Summary of HF digital modes Four categories (I ve broken them down into) Single character, keyboard to keyboard modes RTTY, PSK31, PACTOR, THROB, OLIVIA, JT6M, DOMINO, THOR, JT65, G-TOR, FT8, etc, etc, etc Images SSTV, Hellschreiber Computer processed, Grouped sets of characters sent, then processed by a computer at the receiving end and displayed accordingly APRS, CLOVER Some that don t really fit the above categories WSPR, ROS, WinLink

6 Now, the Digital Voice Modes (mostly associated with VHF/UHF) EchoLink IRLP D-Star (Icom) System Fusion (Yaesu) P25 NXDN (Icom & Kenwood) DMR (several Chinese manufacturers, Kenwood) A few words on trunked radio systems First, before there was digital, there was analog

7 Frequency Modulation Mhz In Mhz Out By the way, I m not turning on my transmitter unless I hear a hz tone Transmits on Mhz Hears on Mhz

8 Frequency Modulation = Amplitude of your voice causes Frequency Deviation -20Khz -15Khz -10Khz -5Khz 0 +5Khz +10Khz +15Khz +20Khz -20Khz -15Khz -10Khz -5Khz 0 +5Khz +10Khz +15Khz +20Khz Generally speaking, 15Khz of deviation is normal, which means, in practice 20Khz of BW used

9 Purpose of going Digital? 1912, conserve bandwidth (Radio Act of 1912) 1930 s, conserve bandwidth (Single Side Band) Today? Digital? Conserve bandwidth Next question, how to digitize your voice

10 How to turn your analog voice into a digital bit stream LOTS of A/D and D/A converter algorithms specifically designed for converting voice into digital (VOCODER) LPC-10, 2400 bit/s, linear predictive coding Code-excited linear prediction (CELP), 2400 and 4800 bit/s (STU-III) Continuously variable slope delta modulation (CVSD), 16 kbit/s Mixed-excitation linear prediction (MELP), (FNBDT) Adaptive Differential Pulse Code Modulation (ADPCM) (STE) Algebraic code-excited linear prediction (ACELP 4.7 kbit/s 24 kbit/s) Mixed-excitation linear prediction (MELPe 2400, 1200 and 600 bit/s) Multi-band excitation (AMBE 2000 bit/s 9600 bit/s) Sinusoidal-Pulsed Representation (SPR 600 bit/s 4800 bit/s) Robust Advanced Low-complexity Waveform Interpolation (RALCWI 2050bit/s, 2400bit/s and 2750bit/s) Tri-Wave Excited Linear Prediction (TWELP 600 bit/s 9600 bit/s) Noise Robust Vocoder (NRV 300 bit/s and 800 bit/s)

11 A/D and D/A conversion -Since it s now a digital signal, degraded signals can be fixed with FEC -Can also be compressed for even less bandwidth 11

12 EchoLink (a VoIP Ham Protocol) Internet PC PC 2 Meter Repeater Mic Headphones CQ CQ Anybody on this repeater?

13 EchoLink A Voice Over IP (VoIP) system EchoLink uses standard H.323 You can log into the EchoLink system (echolink.org), and then attach to any repeater system associated with EchoLink Must first create an account at echolink.org by providing proof you re a licensed amateur radio operator Once you re connected to a repeater, you re 59 into the repeater! Or, you can connect two PCs and talk to each other

14 ITU-T standard H.323 Includes many protocols The standards most relevant to EchoLink are the audio codecs (coder/decoders) (These are the A/D and D/A converters using a variety of algorithms) G.711 (64 Kbits/S) G.729 (8 Kbits/S) G (5.3 or 6.3 Kbits/S) G.726 (16, 24, 32 an 40 Kbits/S) G.722 (48, 56, 64 Kbits/S) G.728 (16 Kbits/S) Speex (Audio Compression algorithm) AAC-LD (Audio Compression algorithm) Usually, some sort of hand shaking occurs at initial connection establishment to determine the best codec to use

15 EchoLink Encoding: Voice to Digital conversion through the use of one of many H.323 codecs Frame Format: the IP Packet Authenticated connection, followed by Voice over IP (VoIP)

16 IP Packet International Standards Organization Open System Interconnect Model 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data 1. Physical MAC Application, software, program, app programmer s choice! IP TCP MTU MAC The Wire or Radio or Fiber Optic TCP or UDP Segment IP Packet MAC Frame

17 IRLP Internet Radio Linking Project Another VoIP protocol Main purpose is to link repeaters (Freedom Link is not IRLP, they re linked via RF point-to-point connections using 70cm links in many instances, I think )

18 D-Star (Icom) Digital Smart Technologies for Amateur Radio The first digital voice and data protocol designated for amateur radio Objective: use less bandwidth Encoding: AMBE vocoder (AKA codec) (closed source) Used by Inmarsat, Iridium and some XM Sat Radio channels Gaussian Minimum Shift Keying (GMSK) modulated carrier Frame Format: D-STAR Digital Voice protocol standard (DV) 3.6 Kbits/S followed by 1.2 Kbits/S of FEC On-Air DV rate is 4.8 Kbits/S Can link repeaters over the internet Kenwood and Flex make compatible radios

19 D-Star (Icom)

20 D-Star (Icom)

21 D-Star 1 st, you must register your call sign, otherwise, you ll be limited to the local repeater Generally, find the person who maintains the local D-Star repeater and ask nicely You must only be registered by the operator of a single repeater Then, program your radio Can do it from the front panel, but it s easier to use a computer program Four parameters: MYCALL, URCALL, RPT1, and RPT2 Then set mode ( DV ) and frequency/repeater offset Next slide

22 D-Star MYCALL your own call sign. You can add / and other characters like /P or /M or /7 or /BOB or /92 (for IC-92AD) URCALL can hold routing info or linking commands; to use your local repeater, just set it to CQCQCQ RPT1 should be set to your local repeater This setting doesn t matter for simplex RPT2 designates where you want your signal to be routed; normally it s set to your local repeater followed by <space> G <space> G = Gateway This setting doesn t matter for simplex Can tell you what to put in these fields based on what you want to connect to Next slide

23 D-Star module, port, node are synonymous A (module/port/node) = 1.2 Ghz B (module/port/node) = 440 Mhz C (module/port/node) = 144 Mhz Call Sign Routing Next couple of slides

24 D-Star Call Sign Routing Using local repeater (no routing) N5VGQ just wants to talk to other local hams using his local repeater K5LET, which is on 440 Mhz (node B), using local repeater K5LET as the Gateway MYCALL: N5VGQ URCALL: CQCQCQ RPT1: K5LET B RPT2: K5LET G

25 D-Star Call Sign Routing Routing to specific repeater and node N5VGQ is using his local repeater K5LET and wants to route his transmissions to the B node of the JP1YDS repeater in Japan MYCALL: N5VGQ URCALL: /JP1YDSB RPT1: K5LET B RPT2: K5LET G

26 D-Star Call Sign Routing Routing to specific repeater and node last used by a specific ham N5VGQ is using his local repeater K5LET, and WB5UAA is on vacation somewhere in the world; N5VGQ wants to route his transmissions to what ever repeater WB5UAA used most recently (in hopes of finding/talking to him) MYCALL: N5VGQ URCALL: WB5UAA RPT1: K5LET B RPT2: K5LET G

27 D-Star Linking to another repeater N5VGQ wants to link his local repeater K5LET to the B module of repeater W5ETX in Tyler MYCALL: N5VGQ URCALL: W5ETXBL RPT1: K5LET B RPT2: K5LET G

28 D-Star Linking to another repeater N5VGQ wants to link his local repeater K5LET to Reflector 14C, to which many other West Coast repeaters are already linked MYCALL: N5VGQ URCALL: REF014CL RPT1: K5LET B RPT2: K5LET G

29 D-Star UNLINKING a linked repeater N5VGQ wants to unlink his local repeater K5LET from the reflector or other repeater it s currently linked to MYCALL: N5VGQ URCALL: <space><space><space><space>><space><space><space>u RPT1: K5LET B RPT2: K5LET G Key the radio for about a second and you should get a recording played back saying remote system unlinked

30 D-Star Echo Test N5VGQ wants to hear how he sounds on his local D-Star repeater (Echo test) MYCALL: N5VGQ URCALL: K5LET E RPT1: K5LET B RPT2: K5LET G

31 D-Star Information Message N5VGQ wants to find out how his local repeater K5LET is currently linked (Information) MYCALL: N5VGQ URCALL: K5LET I (letter eye ) RPT1: K5LET B RPT1: K5LET G

32 D-Star DV Dongles, DVAPs, Hotspots DV Dongle Little plastic thing that plugs into your computer USB port You can then use your computer s headsets and microphone to connect to a repeater or reflector DVAP Plugs into your computer like a DV Dongle, but has a small antenna on it Instead of using computer headsets/microphone, you use your D-Star radio to talk to the DVAP using DV simplex Range is limited, but you use your D-Star radio to connect to a repeater or reflector through your computer D-Star Hotspot Like a homemade DVAP made using FM radio with a data port, a GMSK adapter board and a computer Can be used by your D-Star radio to connect to a D-Star repeater if you re radio s not in range of a D-Star repeater

33 System Fusion (Yaesu) Yaesu s implementation of Digital Amateur Radio Encoding: AMBE vocoder (AKA codec) (closed source) for Voice to Digital conversion C4FM (4-level FSK) modulated carrier Frame Format: 960 bits, divided into 5 logical slots Wide-coverage Internet Repeater Enhancement System (WIRES-X) is a protocol to link repeaters using VoIP and the Internet

34 System Fusion (Yaesu)

35 Wires-X Screen (Provides a little bit of insight)

36 Connect to a Fusion Repeater Specific step-by-step button pushing instructions for all Yaesu Fusion radios Generally: Connect to a local node (for example) MIWIZ-FUSION AMERICA-LINK WORLD-LINK CQ AMERICA You can then connect to a room Can search by name Can connect by DTMF ID

37 System Fusion Nodes

38 System Fusion Rooms DTMF ID

39 Project 25 (P25) Initiated collaboratively by North American public safety agencies (shortly after September 11, 2001) to address interoperability among emergency communications systems, especially among first responders (city, county, state, federal) Standard: Telecommunications Industry Association (TIA), TIA-102 series, which includes 49 separate parts on LMR and TDMA implementations, including trunked radio systems and the following encryption standards: DES, 3DES, AES, RC4 TIA-102 is the American version of ETSI TS-102 more later (continued next slide)

40 Project 25 (P25) (continued) Planned Time line: Phase 1 - IMBE vocoder, C4FM encoding (a special type of 4FSK), single 12.5 Kbps channel (FDMA), and a frame format consisting of 4.4Kbps of IMBE voice, 2.8Kbs of FEC and 2.4Kbs of signaling and control for a total of 9.6Kbs of total channel throughput Phase 2 - AMBE+2 vocoder, two TDMA channels (6.25Kbs X 2), a frame format which requires only 6Kbs (including FEC and signaling) per channel, and a goal to be backwards compatibility to Analog FM and Phase 1 Future phases still to be determined. TIA was collaborating with the European Telecommunications Standards Institute (ETSI) but stopped in 2010.

41 NXDN Encoding: AMBE2+ vocoder, 4FSK Frame Format: FDMA, 12.5Kbs or 6.25Kbs Can be voice/voice, voice/data, data/voice, data/data Supports a bit stream encryption, and two block encryptions: DES and AES Developed jointly by Icom and Kenwood and accepted at an ITU-R meeting (Study Group 5) in November of 2016 Spin off from P25? Standards also includes Trunking Several other vendors: Motorola, Vertex, and probably some others

42 DMR Encoding: AMBE vocoder (AKA codec) (closed source) for Voice to Digital conversion 4FSK modulated carrier Frame Format: Based on ETSI (European Standards) Open Standard Next slide

43 DMR (is OPEN SOURCE) ETSI standards: TS : Air interface protocol TS : Voice and General services and facilities TS : Data protocol TS : Trunking protocol

44 DMR Frame Format (Air Interface Protocol) 1 st the basic structure

45 The full structure DMR Frame Format (Air Interface Protocol)

46 DMR Frame Format (Air Interface Protocol) Can transfer data or 2 voice channels

47 DMR Standards Tier 1 FDMA Tier 2 2 Slot TDMA IP Site Connectivity (Vendor Specific) Tier 3 2 Slot TDMA Trunking

48 DMR Vendors DMR+ Almost dead DMR-MARC Still a lot, but looks like it s dying Brandmeister Looks like everyone is migrating to BM

49 DMR Vendors DMR+ Originally Hytera Network Almost dead/gone DMR-MARC CBridge, SmartPTT Morotrbo (Motorola Solutions) Everyone has to connect via IP to a master controller, then a central server Still a lot in use, but looks like it s dying Brandmeister Next slide

50 DMR Vendors Brandmeister (BM) Hytera, Mototrbo, Homebrew, MMDVM, DV4Mini, DVMega Everyone connects via IP to a central server Newest, worldwide growth Has more ways to interface Next slide

51 Brandmeister (BM) Interfaces For example, if you re on DMR-MARC network, you can connect to TexasNet (BM TalkGroup 3148) through DMR-MARC TalkGroup 9000, which is linked to BM TalkGroup 3148 Central Alabama has TalkGroup 31015, which is linked to WIRES-X (FUSION) Arkansas has TalkGroup 7227, which is linked to both WIRES-X and D-STAR Central Kansas has TalkGroup 31204, which is linked to WIRES-X, FUSION, and Analog These links are established through DMR reflectors, which are virtual talkgroups which can be linked to other talkgroups and other modes, such as D-Star and Fusion

52 DMR Map cqdmrmap.com

53 DMR Map cqdmrmap.com

54

55 FDMA vs TDMA

56 D-Star vs DMR vs Fusion Flexibility D-Star and Fusion (with WIRES-X) can connect to any other (D-Star or Fusion) repeater in the world that s registered DMR the repeater operator decides which talk group(s) you have access to See

57 Common (BM) DMR TalkGroups Currently Used in Texas Updated: 9/17 Talk Group ID Talkgroup Name Notes 1 Worldwide Any Language 2 Local/Metro Common Local Area Metro or Local Repeaters 8207 Houston Area Local Activates all Upper Gulf Coast Repeaters 3 North America United States/Canada (DMR-MARC) 13 Worldwide English English Only 310 TAC 310 North America Repeater-to-Repeater TG 311 TAC 311 International Repeater-to-Repeater TG 312 TAC 312 Repeater-to-Repeater TG 1776 USA "USA 1776" by MITCOM 3140 OK Statewide Now on the Brandmeister Network 3148 Texas Statewide "Lonestar Talk Group" 3100 DCI Bridge 3106 NorCal Bridge 3173 Mid-Atlantic WV/VA/MD/DE 3174 Southeast AR/LA/MS/KY/TN/AL/FL/GA/SC/NC/PR 3175 Southern Plains TX/OK/KS/AR 3185 Cactus TX/AZ/CA 99 Simplex TG for Simplex Use. Time Slot 1, Color Code 1 generally 9999 NorCal Audio Test Notes: Not a complete list of all Talk Groups.

58 Couple notes about DMR Talk Groups- a way for users to share a time slot Zones - a group of individual channels Color Codes - much like CTCSS(PL) or DCS on analog Code Plugs - a radio s configuration file To access a DMR repeater, program the following in your radio: Frequency Color Code Talk group Talk-Around Talking simplex on the repeater s output frequency Published simplex frequencies: 441.0, 446.5, , , , to get off the repeater frequency TG99, CC1, TS1 Generally accepted

59 D-Star vs DMR vs Fusion Survivability First, they ll all work as repeaters by themselves Internet connectivity: D-STAR uses DNS, if one node goes down, no problem, you can connect to any other still on the internet There is no reliance on a central control system DMR if it loses connectivity to a central controller, it doesn t work over the internet any more Fusion (with WIRES-X) The central controller is in Tokyo, Japan

60 D-Star vs DMR vs Fusion Survivability - what if the internet goes down? Several references to people using Amateur Radio Emergency Data Network (AREDN) to connect up D- STAR nodes, Fusion repeaters and DMR repeaters Each has its own set of challenges in connecting to an internet system not connected to the real internet (mostly to do with unknown background port activity) What is AREDN? It's your typical store-bought home internet wireless router, flashed with new software, set up as point-to-point links and meshed for throughput and reliability on a /8 subnet

61 AREDN

62 AREDN

63 Current known locations of AREDN nodes

64 D-Star vs DMR vs Fusion For all three, there s a device called a DV4Mini that allows you to access the internet; however: DMR Connects via reflector connections only (limited talk groups) Partial list of DMR reflectors next slide Fusion Can talk digital, but no WIRE-X D-Star This is only one of many ways to connect to the internet and there are new ones coming out regularly

65 Partial DMR Reflector List Lot s more

66 D-Star vs DMR vs Fusion Manufactures DMR Has the most manufacturers D-STAR Icom is the main manufacturer but others manufacture cards to make their radios D-STAR compliant Fusion Yaesu only

67 D-Star vs DMR vs Fusion Connections Big difference between D-Star/Fusion and DMR D-Star/Fusion you tell the repeater (or another device) what you want to connect to DMR the repeater tells you what you can connect to

68 D-Star vs DMR vs Fusion Digital ID D-Star/Fusion send your call sign digitally every time you key up (meets Part 97 requirement) DMR doesn t (it sends a subscriber ID number) Voice Quality DMR/Fusion good voice quality (12.5 Kbps) D-Star sounds mechanical (6.25 Kbps)

69 D-Star vs DMR vs Fusion Concurrent Voice Channels DMR is the only mode which supports 2 different voice channels (time slots 1 and 2) Mixed mode D-Star does not support analog DMR can support analog Fusion was designed to support both digital and analog

70 D-Star vs DMR vs Fusion Published standards DMR Open standards have a tendency to win in the long run

71 A few words on commercial trunked systems Encoding/Frame format: can be any number of what s already been mentioned, and can be any number of frame formats Standards: OpenSky System APCO Project 16 dpmr mode 3 DMR Tier III NXDN Kenwood has NEXEDGE Digital trunked radio Icom IDAS Digital trunked Land Mobile Radio Hytera DMR Tier 3 Trunking Lite Motorola iden, Capacity Plus, Connect Plus, Harmony

72 Idea of trunked radio system Fix the problem in high density areas where there are more radio services required than spectrum has to offer Based on the idea that not EVERYONE is going to be talking on the radio AT THE SAME TIME Simple example following slides

73 Podunk Town, USA Police Fire EMS City workers Water Electricity Sanitation School district Animal control Frequency allocation for Podunk: 801 Mhz 802 Mhz 803 Mhz Only 3 radio channels for 9 services!!!

74 Basic idea of trunked radio system Every radio has a physical address Each physical address is assigned to a group at the repeater When one person in a group keys his radio, everybody else in that group receives If you re not a member of that group, you don t hear anything Every radio goes through a repeater which assigns the physical frequency/channel dynamically Of course, going through a codec which requires minimum bandwidth also And these frames can have some sort of basic encryption to prevent prying eyes from seeing what s going on

75 Podunk Town, USA Police radio keyed up, repeater assigns 801 Mhz 801 Mhz 802 Mhz 803 Mhz

76 Podunk Town, USA Police radio keyed up, repeater assigns 801 Mhz 801 Mhz now in use Fire keys a radio, repeater assigns 802 Mhz 801 Mhz 802 Mhz 803 Mhz

77 Podunk Town, USA Police radio keys radio, repeater assigns 801 Mhz 801 Mhz now in use Fire keys a radio, repeater assigns 802 Mhz 802 Mhz now is use 801 Mhz 802 Mhz 803 Mhz

78 Podunk Town, USA Police radio keys radio, repeater assigns 801 Mhz 801 Mhz now in use Fire keys a radio, repeater assigns 802 Mhz 802 Mhz now is use Police finishes transmission, unkeys radio 801 Mhz 802 Mhz 803 Mhz

79 Podunk Town, USA Police radio keys radio, repeater assigns 801 Mhz 801 Mhz now in use Fire keys a radio, repeater assigns 802 Mhz 802 Mhz now is use Police finishes transmission, unkeys radio 801 Mhz now clear 801 Mhz 802 Mhz 803 Mhz

80 Podunk Town, USA Fire finishes transmission, unkeys radio 801 Mhz 802 Mhz 803 Mhz

81 Podunk Town, USA Fire finishes transmission, unkeys radio All channels clear 801 Mhz 802 Mhz 803 Mhz

82 Podunk Town, USA Response to 1 st fire is answered, repeater assigns 801 Mhz 801 Mhz now in use 801 Mhz 802 Mhz 803 Mhz

83 Podunk Town, USA Response to 1 st fire is answered, repeater assigns 801 Mhz 801 Mhz now in use Response to 1 st Police is answered, repeater assigns 802 Mhz 801 Mhz 802 Mhz 803 Mhz

84 Podunk Town, USA Response to 1 st fire is answered, repeater assigns 801 Mhz 801 Mhz now in use Response to 1 st Police is answered, repeater assigns 802 Mhz 802 Mhz now is use 801 Mhz 802 Mhz 803 Mhz

85 Podunk Town, USA Response to 1 st fire is answered, repeater assigns 801 Mhz 801 Mhz now in use Response to 1 st Police is answered, repeater assigns 802 Mhz 802 Mhz now is use EMS keys radio to transmit, repeater assigns 803 Mhz 801 Mhz 802 Mhz 803 Mhz

86 Podunk Town, USA Response to 1 st fire is answered, repeater assigns 801 Mhz 801 Mhz now in use Response to 1 st Police is answered, repeater assigns 802 Mhz 802 Mhz now in use EMS keys radio to transmit, repeater assigns 803 Mhz 803 Mhz now in use 801 Mhz 802 Mhz 803 Mhz

87 Podunk Town, USA Response to 1 st fire is answered, repeater assigns 801 Mhz 801 Mhz now in use Response to 1 st Police is answered, repeater assigns 802 Mhz 802 Mhz now in use EMS keys radio to transmit, repeater assigns 803 Mhz 803 Mhz now in use Trunking system now MAXED OUT! 801 Mhz 802 Mhz 803 Mhz

88 Podunk Town, USA City worker tries to key a radio, doesn t get the beep to start talking Police unkeys Frees 802 Mhz 801 Mhz 802 Mhz 803 Mhz

89 Podunk Town, USA City worker tries again, repeater now gives 802 Mhz to him At the same time, Fire finishes and EMS finishes 801 Mhz 802 Mhz 803 Mhz

90 Podunk Town, USA City worker tries again, repeater now gives 802 Mhz to him At the same time, Fire finishes and EMS finishes Two others now available for whoever keys up next 801 Mhz 802 Mhz 803 Mhz

91 Trunked Radio Systems So, you just need a good idea on peak times to know how many actual channels you need based on how many services are going to be connected and the busiest times Many old fashioned telephone trunking algorithms to figure this out fairly accurately It comes down to probabilities

92 Trunked Radio Systems So who ll be the first to come up with a trunked ham repeater system?

93