1 / 28

EchoLink

EchoLink. Amateur Radio meets Voice over the Internet Protocol. Andy Zwirko – K1RA http://go.to/andyz andyz@sort.net. Overview. VoIP Concepts and Terminology Analog, Digital, Samples, Buffers Packets, Client/Server, TCP/IP Ham VoIP Projects Access, Modes, Connecting, Audio Quality

paul
Download Presentation

EchoLink

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EchoLink Amateur Radio meets Voice over the Internet Protocol Andy Zwirko – K1RA http://go.to/andyz andyz@sort.net

  2. Overview • VoIP Concepts and Terminology • Analog, Digital, Samples, Buffers • Packets, Client/Server, TCP/IP • Ham VoIP Projects • Access, Modes, Connecting, Audio Quality • Topology, Users, Is this ‘Ham Radio’? • EchoLink Software Graphical User Interface • Setup, Radio, Computer • Modes, Configuration • Radio Interfaces • K1RA-L Live Node Demo • Good Practices • Common Problems

  3. What is VoIP? • Convert Voice to Digital 1’ 0’s (A/D) • Compress Digital Data (Encode) • Buffer digital sample data into packets • Send packet buffers via Internet Protocol • Receive and assemble packet buffers • Uncompress Digital Data (Decode) • Convert Digital 1’s 0’s to Voice (D/A)

  4. A/D – D/ATerms and Concepts • Analog <> Digital • Continuous <> Discrete • Air Pressure <> Volts • Sampling Rate • Freq. (KHz) 8, 11, 22, 44 • Unit time (secs) • Sampling Bits • Quantization (#) 2^8, 2^16 • Dynamic range (dB) 50, 98 • Nyquist Theorem • Sample Rate >= 2 x Freq.

  5. Encode / DecodeCompress / Decompress • Codec Types • GSM (E/L 8kbps) • uLaw • aLaw • ADPCM • Function • Don’t send dead air • Combined similar values • Save space and time

  6. Internet and IP • Hosts • Routers • Dotted Decimal Addresses • Transport (TCP/UDP) • Source & Destination Ports • Data / Buffers • Checksum

  7. Connecting via VoIP • Two methods / implementations • Client / Server (Middleman) • Client is Authenticated (Callsign / Password) • Client Requests Users List ( Callsign, IP Addr.) • Client Makes Connection to User • No Central Server (Client to Client) • Client Must manually obtain remote IP Addr. • Client Makes Connection to User

  8. Amateur Radio VoIP Projects • EchoLink – http://www.echolink.org/ • IRLP – http://www.irlp.net/ • CQiNet – http://cqinet.sourceforge.net/ • WIRES II – http://www.vxstd.com • eQSO – http://www.eqso.net/

  9. Echolink Overview • Link Radio Amateurs via the Internet • PC-PC Users, PC-RF Gateways, RF-RF • Simple Password Access to Server • “By Hand” Callsign check for Password Validation • GSM Vocoder 8kbps/user • Lower Voice Quality (Dial-up or Broadband ISP) • Multiple Connections per Node Possible • Bandwidth Limited (Broadband Required for Conf) • Node Information (http://www.echolink.org/logins.asp) • 2700 Active Nodes Worldwide • 552 Users, 1064 Links, 962 Repeaters, 122 Confs.

  10. VoIP Network Topology 209.176.50.1 68.54.3.2 K1HTV K1RA 128.10.60.73 WA3NAN-R 212.50.33.5 141.9.5.102 NA3J/0

  11. PC to PC

  12. Sys Op Mode

  13. Simplex Link

  14. Repeater Link

  15. PC Users, Links, Repeaters

  16. EchoLink - The Software • Windows • Mac • Linux • Sysop • User

  17. Interfaces • Types • Commercial • Homegrown • Function • Isolate • Attenuate • Match • Key PTT • COR

  18. Commercial Interfaces

  19. DIY Interface Schematic

  20. K1RA-L • Echolink node #199756 • Warrenton, VA – FM18cr - ~ 550ft ASL • 144.440 MHz Simplex - ~20w • Adelphia Cable ISP - 4Mbps / 512Kbps • Supports 4 simultaneous users • Software version 1.980 • Access is Open 24/7

  21. Node Hardware • Radio Equipment • ICOM IC207H • 20 Watts • 5/8ths vertical @25ft • 12v 20A P.S. • Computer Equipment • Pentium II – 350MHz • 192 MB RAM • 6 GB Hard Disk • 10baseT NIC • Linksys D614+ FW • 2000VA UPS

  22. Control Operation • 3 Levels of Control • DTMF over Link Frequency • HTTP Web Interface • Direct PC Keyboard • Control Operators • K1RA - Andy • KZ1AMY - Amy

  23. Node DTMF Commands • Status – 08 • Connect – 4, 5, 6 digit node number • Echo Test Server = 9999 • short cuts, ex: *90 = WA3NAN-R • Disconnect - # • Reconnect – 09 • Help File -*411

  24. Good Operating Practices • Identify Yourself • When connecting • When sending DTMF • Pause, Wait, Listen • Use DTMF Status Command 08 • Rag chewers beware • 3 minute timeout

  25. Common Problems • Connection Timeout • Disconnects • Audio issues • Broken • Garbled • Drop outs

  26. Local EchoLink Nodes List

  27. Local EchoLink Nodes Map

  28. Question?Tnx & 73 ! Andy Zwirko – K1RA http://go.to/andyz andyz@sort.net

More Related