资料来源 : Free On-Line Dictionary of Computing

amateur packet radio
     
         (PR) The use of {packet radio} by amateurs to
        communicate between computers.  PR is a complete amateur radio
        computer 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, currently
        most links between digipeaters) and higher frequencies.  There
        is a KW (short wave) Packet Radio at 300 BPS, too.
     
        Satellites with OSCAR (Orbiting Sattelite Carring Amateur
        Radio) transponders (mostly attached to commercial satellites
        by the AMateur SATellite (AMSAT) group) carry Packet Radio
        mailboxes or {digipeaters}.
     
        There are both on-line and off-line services on the packet radio
        network: You can send {electronic mail}, read bulletins, chat,
        transfer files, connect to on-line DX-Clusters (DX=far
        distance) to catch notes typed in by other HAMs about the
        hottest international KW connections currently coming up (so
        you can pile up).
     
        PR uses {AX.25} (an {X.25} derivative) as its {transport
        layer} 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} to
        forward mail.  Sometimes mails travels over satelites.
        Normally amateur satellites have strange orbits, however the
        mail forwarding or maibox satellites have very predictable
        orbits.  Some wormholes allow HAMs to bridge from Internet to
        {AMPR-NET}, e.g. db0fho.ampr.org or db0fho.et-inf.fho-emden.de,
        but only if you are registered HAM.
     
        Because amateur radio is not for profit, it must not be
        interconnected to the {Internet} but it may be connected
        through the Internet.  All people on the (completely free)
        amateur radio net must be licensed radio amateurs and must
        have a "call" which is unique all over the world.
     
        There is a special {domain} AMPR.ORG (44.*.*.*) for amateur
        radio reserved in the IP space.  This domain is split between
        countries, which can further subdivide it.  For example
        44.130.*.* is Germany, 44.130.58.* is Augsburg (in Bavaria),
        and 44.130.58.20 is dg8mgv.ampr.org (you may verify this with
        {nslookup}).
     
        Mail transport is only one aspect of packet radio.  You can
        talk interactively (as in {chat}), read files, or play silly
        games built in the Packet Radio software.  Usually you can use
        the autorouter to let the digipeater network find a path to
        the station you want.  However there are many (sometimes
        software incompatible) digipeaters out there, which the router
        cannot use.  Paths over 1000 km are unlikely to be useable for
        {real-time} communication and long paths can introduce
        significant delay times (answer latency).
     
        Other uses of amateur radio for computer communication include
        {RTTY} ({baudot}), {AMTOR}, {PACTOR}, and {CLOVER}.
     
        {A huge hamradio archive (ftp://ftp.ucsd.edu/hamradio/)}.
     
        {Usenet} newsgroup: {news:rec.radio.amateur.packet}.
     
        (2001-05-12)