The Internet Radio Linking Project

1
The Internet Radio Linking Project
I.R.L.P

• Presented by K1IMD
• For the Peconic Amateur Radio Club
• 1 June 2001 Meeting

Portions of this presentation are reproduced by
written permission of David Cameron VE7LTD
2
Topics of Discussion

• Jon K1IMD
• IRLP System Designer
• Introduction
• History of Linked Repeaters
• How it Started
• IRLP Node Equipment
• Hardware
• Pictures of Node 449
• Pictures of Node 448
• Pictures of a typical IRLP Node Installation

• Modes of Operation
• Reflector Mode
• Point to Point Mode
• What does it (Voice over IP) sound like?
• What does a QSO Sound like
• IRLP Node Status
• IRLP Operation
• How To IRLP
• Non-Amateur Uses of IRLP
• The END!!

3
Jon Andrews K1IMD

• Jon Andrews was first licensed as an amateur in
  1971 where he was issued a novice license WN2CBX.
  A year after his novice license expired he
  retook the exam and was again issued a novice
  license with the call WN2YVL, shortly after that
  in 1974 he took the Technician exam and was given
  the callsign WA2YVL. In 1995 Jon passed his
  Advance class license exam and soon changed his
  callsign to K1IMD.
• Jon has experimented with many facets of the
  hobby, Fixed Station and Mobile operation. VHF,
  UHF and Microwave and modes including CW, AX.25
  Packet, TCP/IP Packet, FM FM Repeaters, AM,
  SSB, AMTOR, RTTY, SSTV, and Fast Scan ATV.
  However, of most interest over the years has been
  in linking FM voice repeaters. In his basement
  he has a shop where he likes to tinker with
  projects in his limited spare time.
• Jon stays busy with his family and work but does
  still find time to experiment, build some
  projects and maintain some equipment of others.
  Jons latest experiment is the Internet Repeater
  Linking Project pioneered and designed by David
  Cameron VE7LTD.
• Jon is the Chairman of the Board of the Peconic
  Amateur Radio Club and an active participant in
  the local ARES unit where he serves as an AEC.

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IRLP System Designer
Note! Important Point David is NOT an ole
Buzzard Ham

• Callsign VE7LTD   Codes E   CANADA
• Name David Cameron
• Addr1 4708 CAULFIELD DRIVE
• Addr2 WEST VANCOUVER, BC V7W1G2,
• Country CANADA
• Lookups 130 
• Birthday 06 Aug 1975
• Email ve7ltd_at_irlp.net
• Home Page http//www.irlp.net
• The above courtesy of http//www.qrz.com

5
Introduction

• The aim of the Internet Radio Linking Project
  (IRLP) is to provide a simple and easy system to
  link radio systems together using the Internet as
  the communications backbone.
• Similar linking options exist, but they use
  expensive leased telephone lines or satellite
  equipment. It is not the goal of this project to
  compete, but to work along with other networks to
  improve the technology and improve radio linking
  for all involved parties. The people who benefit
  most from the IRLP are its users.
• The software and hardware requirements are
  minimal, and the cost to set up a node is low.
  This brings the opportunity for smaller more
  remote locations, or small clubs, to experience
  national linking without the large capital cost
  of a satellite node or leased line.

This and the next 4 slides are taken from the
IRLP website and as spoken by VE7LTD
6
History of Internet Linking

• Back in December of 1996, I was flipping through
  the many magazines at the UBC club. I came across
  the December 1996 issue of the QST Amateur Radio
  magazine that had the words "Link your repeater
  to the Internet" written on it. I had a quick
  read through the issue and found a well written
  article by James Millner, WB2REM entitled 'A New
  "Band" for Your Radio'. At first glance, I was
  hooked. What more could I ask for? It was a
  combination of the two hobbies that I love the
  most.
• My first connection used VocalTec's Iphone. The
  original article by WB2REM used Iphone to send
  the voice over the internet. I did have some
  problems with the software, mainly in the fact
  that Iphone is not very stable nor is it
  controllable. After running Iphone for close to 6
  months on active connections to Vernon BC and St.
  John NB, I decided that the stability and control
  were key. That is when I started getting into
  using LINUX as an operating system and Speak
  Freely as a client/server.
• Speak Freely is a voice over IP client/server
  package that transmits live audio (i.e. speech)
  over the internet with surprising clarity and
  quality. This program basically allows any two
  parties anywhere on the internet to have a voice
  conversation with each other in real time. My
  objective, and the objective was to use this
  program to link to radio equipment so that voice
  connections can be made without the operator
  being tied to a computer. This will allow hams
  from all around the world to talk to one another
  without relying on radio conditions.

7
History Continued

• Many amateurs have raised a very important
  question regarding this kind of system What if
  non-ham users start connecting to ham repeaters?
  With all the experienced "hackers" out there, I
  can not say that this system is totally
  bullet-proof. I have designed safeguards into my
  software to reject calls from "non-hams".
• The main hurdle I had to overcome was the
  interface between the computer and the radio.
  From my experience with VOX circuits under
  Iphone, I decided that I HAD to find an alternate
  way to start sending audio and to key the radio
  when audio came in (from the internet side).
  Since the source code for Iphone was not
  available, I had to look for an alternative. I
  was told about Speak Freely by a friend of mine,
  and I decided to give it a try.
• I played around with modifying the source code
  for several weeks and finally came up with some
  code that works. The software starts the link
  radio transmitting once packets have been
  received over the internet and unkeys once they
  stop coming in. The software starts sending audio
  once a signal is received and continues to send
  it until the signal is removed. This logic
  control is performed using the parallel port of
  the computer and all the computer chips are on a
  separate interface controller board. I have
  designed this board, and I am building them and
  selling them at cost to promote the project.

8
History - Conclusion

• The whole system is DTMF controllable. The
  control codes lie imbedded in a separate program
  that reads the DTMF tones from the decoder chip
  (located on the interface controller board) and
  activates various parts of the software. DTMF
  codes are used to enable/disable linking,
  open/close links and set identifiers. Every site
  will have the ability to connect direct to any
  other site(s), either using direct connections or
  reflector sites.
• So in a period of 8 months, I switched from a
  piece of software and hardware that someone else
  built, to my own creation which solved all the
  previous problems I was experiencing! Ever since
  the IRLP started, I have never again looked to
  Iphone or Windows for an option in the system.
• This history section is taken by permission
  from http//www.irlp.net website and is in
  VE7LTDs words of his Project History

9
How IRLP Started

• The Internet Radio Linking Project was started
  back in November of 1997 as an attempt to use the
  internet to link radio systems across Canada. The
  first full time link that was established ran
  from Vancouver, BC to Saint John, NB. The link
  had many problems and was shut down in March of
  1998 due to the numerous computer crashes and
  repeater lockups it was causing, and the lack of
  user control over the system.
• I set out to design a better way to use the same
  technology to perform the same task, while
  improving usability, user control, and sound
  quality. My first breakthrough was to replace the
  existing operating system, Windows, with a more
  stable and versatile language. I chose Linux, an
  open source form of the operating system UNIX
  designed by Linus Torvolds, because of its
  superior networking characteristics, its
  reliability, and its ease of programming. P.S
  Thanks to those on SLASHDOT for clarifying this!
• I designed my own interface board to interface
  the radio to the computer. This allowed a large
  amount of delay to be removed from the system
  because two VOX circuits were no longer being
  used . I also wrote my own custom control
  software, and modified an existing voice-over-IP
  software package to accommodate the project.
• The final product was a combination of hardware
  and software that created a nearly seamless radio
  link between two remote sites on the internet.
  The product works so well that many people can
  not believe that they are talking through a link
  at all!

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ILRP Node Equipment

• IBM Clone Computer 80486DX4-100, 80586-75 or
  faster
• VGA Monitor
• Keyboard no mouse is used
• Functional Printer Port on LPT1
• Red Hat LINUX Ver 6.2 running in text mode
• IRLP files which is on the Custom RH LINUX CD-ROM
• Creative Sound Blaster Sound Card
• IRLP Ver 2.0 Interface Board
• Internet Connection that supports at least
  8K/s-64K/s
• With 7 ports mapped from a router or directly
  connected
• Link Radio or Direct Connection to a Repeater
• Installation Instructions downloaded from the
  IRLP website

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Hardware

• The Custom Red Hat CD-ROM
• Red Hat Boot Floppy Diskette

• Custom PCB by VE2LTD
• PCB Does COR, PTT DTMF
• DB9 IRLP to Repeater Interface
• LPT1 to IRLP Jumper Cable

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Pictures of Node 449
Rear View of CPU with IRLP board installed
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Pictures of Node 449
CPU side view with IRLP Board installed
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Pictures of Node 449
CPU with Software Hardware installed in a
small case ready to go
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Pictures of Node 448
Node 448 installed in K1IMD Repeater Rack
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Pictures of Node 448
The K1IMD Repeaters System Rack Dont ask where
the Red Wire Goes!!!!
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Typical Node Setup No.1
8-64Kb Internet connection To another IRLP Node
RF Link
CATV/xDSL MODEM
10Mb Ethernet Connection
Repeater or Remote Base
PTT COR Audio
Router
RF Link
10/100Mb Ethernet Connection
Repeater Controller Link Port
Link Xcvr
Link Xcvr
PTT COR Audio
PTT COR Audio
IRLP Computer w/ Custom Red Hat 6.2 O/S
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Typical Node Setup No.2
8-64Kb Internet connection To another IRLP Node
RF Link
CATV/xDSL MODEM
10Mb Ethernet Connection
Repeater or Remote Base
RF Link with CTCSS gating COS
PTT COR Audio
Router
10/100Mb Ethernet Connection
Repeater Controller Link Port
PTT COR Audio
Link Xcvr
IRLP Computer w/ Custom Red Hat 6.2 O/S
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Node 448 K1IMD
8-64Kb Internet connection To another IRLP Node
RF Link
CATV MODEM
Micor UHF Repeater
10Mb Ethernet Connection
PTT COR Audio
ACC RC-850 Repeater Controller On Link Port 3
NetGear RT314 Router
PTT COR DTMF Audio
10/100Mb Ethernet Connection
IRLP Computer P-166MMX w/ Custom Red Hat 6.2 O/S
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Modes of Operation

• There are two modes of IRLP operation
• Reflector Mode Streaming Multiple Audio Streams
• Much like a party line everyone hears everyone
  else
• Point to Point Mode Only two repeaters are
  linked
• This mode is much like linking two repeaters
  together via a link radio or remote base

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Reflector Mode
RPTR
RPTR
RPTR
RPTR
RPTR
IRLP Reflector
RPTR
RPTR
22
Point to Point Mode
RPTR
IRLP Server
RPTR
23
What does it sound like?
Voice over IP (VoIP) must sound Weak, Buzzy,
Crummy Digital Sounding Voice NOT!!

• The underlying VoIP software is a program called
  Speak Freely it is digital and sounds GREAT!
• In fact, unless you knew you where connected to a
  data link, you would never know!
• Everyone sounds like locals!!

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What a QSO Sound Like?
Reflector Mode

• This is an actual connection and QSO on the IRLP
  Reflector 2 Denver, Colorado on 5/10/2001 at
  about 1830 EDT
• Sounds pretty good huh?
• (This audio was captured via the microphone on my
  PC and accessing the system with my HT)

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What a QSO Sound Like?
Direct - Point to Point Mode

• This is an actual connection and QSO to the
  VE1NSG Node in Halifax, NS on 5/17/2001 at about
  2010 EDT
• Sounds GREAT huh?
• (This audio was captured via the microphone on my
  PC and accessing the system with my HT)

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IRLP System Node Status

• To see an active update of the IRLP network and
  nodes activity go to
• http//www.irlp.net/15-status/body.html
• Many nodes have a single page webpage that gives
  local information about the node, repeater or
  location at
• http//www.irlp.net/05-nodes/body.html

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IRLP - Eastern Long Island, New York - Node K1IMD
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IRLP Operation

• IRLP is very much similar to other linked
  repeater systems. The only difference is that
  the link is done via the Internet utilizing VoIP
  (wire) v.s. a telephone pair or a RF link via
  radio or microwave.
• What this means is that in when you push your
  Push To Talk (PTT) button you are actually keying
  ALL repeaters in the network PTT as well.
• This could be only one Repeater in a Point to
  Point Connection or many many repeaters virtually
  all over the world in the Reflector Mode
• You quite literally have worldwide access to
  other IRLP nodes around the world that you can
  link to via DTMF commands

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How To IRLP

• Have a basic understanding how the system works.
• Contact your local Node Op for his/her Rules on
  use of his/her repeater, link system and the IRLP
  system interconnect.
• In general, some node ops leave the system
  connected on a Reflector. The most active and
  common reflector is Reflector 2 in Denver
  Colorado. Other node ops leave the system
  disabled but available to be connected on DTMF
  commands.
• Once the local repeater is connected to the IRLP
  network, you can commence with a normal QSO as
  you would with a local.

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How To IRLP

• However, there are some courtesy's and protocols
  that you must follow
• As mentioned on previous slides, you are keying
  up one to many transmitters around the world.
  This takes TIME!! Before you speak Press your
  PTT Button and pause for 2-3 seconds to allow all
  the systems to key-up.
• When a person comes back to you WAIT for 3-4
  seconds before responding this allows others to
  join in the QSO and more importantly, allows node
  control ops to disconnect from the IRLP Network.
  Only one node can talk at a time and that
  includes controlling!!
• When you sign on the custom is to ID and give
  your geographic location or node you are coming
  in on.
• REMEMBER Like other Amateur Radio modes it
  is a GLOBAL medium and your actions are a
  reflection of you, the node owner, hams in your
  area and the citizens of the country you are
  from!!

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Non-Amateur Radio Uses of IRLP

• We would also like to add that this project does
  not only cover the scope of amateur radio, but
  also includes several commercial applications as
  well. A couple of commercial uses include
• Replacing leased lines used by national carrier
  companies.
• IRLP designed and implemented a central homed
  system for dispatch of multiple vehicles across
  the province of British Columbia using internet
  links, mountain-top repeaters, and remote base
  radios. The IRLP system was interfaced directly
  into an existing console, and the dispatchers did
  not notice a difference in functionality.
• Replacing older technology paging equipment.
• IRLP designed and implemented a multi-cast voice
  paging network (4 transmitters) for a remote
  school district in British Columbia without the
  use of RF based links between sites. This saved
  the school district thousands of dollars in RF
  gear and reduced the operating cost of their
  paging system by 75.
• Monitoring of remote areas for security reasons.
• Connecting people from remote offices together.
• The above information is by David Cameron - VE7LTD

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For More Information

• For more information on NODE 448 contact
• k1imd_at_arrl.net
• For General Information about IRLP, on the WWW
  see
• http//www.irlp.net
• For Node Activity and connection Status, on the
  WWW see
• http//www.irlp.net/15-status/body.html
• For Node Information Web Pages, on the WWW see
• http//www.irlp.net/05-nodes/body.html

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THE END!

• If youre really serious about expanding your
  Repeater Coverage think IRLP!
• Thank you for your interest tonight
• 73 de K1IMD