Skip this Video
Download Presentation
Packet Radio

Loading in 2 Seconds...

play fullscreen
1 / 20

Packet Radio - PowerPoint PPT Presentation

  • Uploaded on

Packet Radio. For Hamradio. 1st. A Little History. ALOHAnet. A class project at the University of Hawaii The Professor was a ham 70 cm was the band The year was 1971 Successfully demonstrated the world’s 1 st random access network and mailbox. Evolution.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Packet Radio' - carl-james

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Packet Radio




ALittle History

  • A class project at the University of Hawaii
  • The Professor was a ham
  • 70 cm was the band
  • The year was 1971
  • Successfully demonstrated the world’s 1st random access network and mailbox
  • ALOHAnet moved from radio to wires.
  • There were several iterations for improved performance
  • 1973 – Bob Metcalf at Xerox invents ethernet
  • Bob Metcalf opens 3Com and the rest is network history.
What’s important about this?
  • Hamradio was first to demo an important capability
  • Dial-up networking was starting up to allow access to E/N connected networks
  • Modems were being maufactured that allowed inexpensive home opertions
  • Dial-up BBS’s were becoming “common”
  • Hams’ curiosity was again piqued.
So what did the hams do?
  • A handful started to experiment with telephone dial-up modems at about 300 Baud
  • A few invented their own modems using the XR series chips
  • The wired protocol, X.25, was adopted for early packet radio
  • X.25 was extended to AX.25 to handle addressing issues.
  • Early BBS’s were patterned on the dial-ups
  • By the Mid 1980 networks of networks were incorporated into amateur packet radio.
  • Phil Kairn, KA9Q, puts TCP/IP on top of AX.25 to extend network capabilities
  • TAPR created the TAPR-2 TNC.
  • AEA, MFJ, Kantronics, and others started to make and sell affordable TNCs based on TAPR-2
  • And now we are up to date.
The Neo Situation
  • AX.25 has been accepted by the ITU as RX.25

It’s the same thing, just the name was changed to fit ITU standards

. 1200 Baud has become a defacto standard

.RX.25 is now standard with a few TCP/IP BBS’s

.From it’s peak in the 80’s to early 90’s, amateur packet mainly supports EMCOM and APRS

  • FSK, 170 Hz. shift is used for 1200B
  • Some TNC’s use 200 Hz. shift
  • Sound cards have begun to replace hardware TNC’s
  • There are no backbones left in the area.
  • Connecting through digis is common
  • Packet radio and the Inet have merged
So, you really want to do it?How to do it and what you’ll need
  • You will need:
  • 2 meter radio
  • Computer running a terminal application
  • Either a TNC or sound card. (I recommend a TNC)
  • The usual 2 meter antenna
  • Cables to hook up everything
  • Time to play and a BBS in line-of-sight
What a BBS Needs
  • 2 meter radio
  • Computer
  • Either a TNC or sound card (I recommend a TNC)
  • BBS Software
  • The usual 2 meter antenna
  • Cables to hook up everything
  • Looks just like a home station, however there will be a need for more storage if there is a lot of traffic.
Some basic things to know
  • Almost all TNC’s today can act as a simple BBS.
  • Any station can digipeat if that capability is turned on
  • TNC based BBS’s can not route
  • All packet networks work on a carrier sense, multiple access (CSMA) basis same as ethernet
  • Packet radio uses error correction, APRS does not
part II
  • There are a number of different BBS types; ie, FBB, NET/ROM, RLI, MBL, etc.
  • There is a general commonality in the commands
  • HF packet is painful, but you can try it on 14.104 MHz.
The Club’s situation and BBS
  • Everything was smoked in a lightning strike
  • AARC was running a Phil Kairns based BBS accepting RX.25 and TCP/IP, JNOS.
  • Digipeating was turned on for range extension
  • AARC could do static routing via radio or ethernet and had at least 5 Gbs of data storage.
  • TCP/IP apps FTP, SMTP, and Telnet were acceptable.
  • Everything should be replaced due to age or lightning.
  • Kantronics KPC-3 - $230.
  • Astron RS-20 - $140.
  • Kenwood TM-281A - $150.
  • A cheap netbook - $200.
  • Assorted cables - $50. (est)
  • Total Est. - $770.