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(PR) The use of packet radio by amateurs tocommunicate between computers. PR is a complete amateur radiocomputer network with "digipeaters" (relays), mailboxes (BBS)and other special nodes.In Germany, it is on HF, say, 2m (300 and 1200 BPS), 70cm(1200 to 9600 BPS), 23cm (normally 9600 BPS and up, currentlymost links between digipeaters) and higher frequencies. Thereis a KW (short wave) Packet Radio at 300 BPS, too.Satellites with OSCAR (Orbiting Sattelite Carring AmateurRadio) transponders (mostly attached to commercial satellitesby the AMateur SATellite (AMSAT) group) carry Packet Radiomailboxes or digipeaters.There are both on-line and off-line services on the packetradio network: You can send electronic mail, read bulletins,chat, transfer files, connect to on-line DX-Clusters (DX=fardistance) to catch notes typed in by other HAMs about thehottest international KW connections currently coming up (soyou can pile up).PR uses AX.25 (an X.25 derivative) as its transportlayer and sometimes even TCP/IP is transmitted over AX.25.AX.25 is like X.25 but the adressing uses HAM "calls" like"DG8MGV".There are special "wormholes" all over the world which"tunnel" amateur radio traffic through the Internet toforward mail. Sometimes mails travels over satelites.Normally amateur satellites have strange orbits, however themail forwarding or mailbox satellites have very predictableorbits. Some wormholes allow HAMs to bridge from Internet toAMPR-NET, e.g. db0fho.ampr.org ordb0fho.et-inf.fho-emden.de, but only if you are registeredHAM.Because amateur radio is not for profit, it must not beinterconnected to the Internet but it may be connectedthrough the Internet. All people on the (completely free)amateur radio net must be licensed radio amateurs and musthave a "call" which is unique all over the world.There is a special domain AMPR.ORG (44.*.*.*) for amateurradio reserved in the IP space. This domain is split betweencountries, which can further subdivide it. For example44.130.*.* is Germany, 44.130.58.* is Augsburg (in Bavaria),and 44.130.58.20 is dg8mgv.ampr.org (you may verify this withnslookup).Mail transport is only one aspect of packet radio. You cantalk interactively (as in chat), read files, or play sillygames built in the Packet Radio software. Usually you can usethe autorouter to let the digipeater network find a path tothe station you want. However there are many (sometimessoftware incompatible) digipeaters out there, which the routercannot use. Paths over 1000 km are unlikely to be useable forreal-time communication and long paths can introducesignificant delay times (answer latency).Other uses of amateur radio for computer communication includeRTTY (baudot), AMTOR, PACTOR, and CLOVER.A huge hamradio archive (ftp://ftp.ucsd.edu/hamradio/).Usenet newsgroup: news:rec.radio.amateur.packet.