AMATEUR RADIO REPEATER INTERNET SERVICES
extract from:- Mendip Repeater Group ELECTRONIC NEWSLETTER WINTER 1998
From:- Henry O'Tani G8OTA
It is generally acknowledged that amateur radio faces diminishing interest.
It is difficult to excite newcomers or for amateur radio operation to even sustain much interest for more than a few months even when having achieved a license. These should be matters of serious concern for every responsible agent of organisation and administration of amateur radio, requiring immediate attention and urgent remedy.
High Street Competition offers many kinds of new consumer products offering superior performance and features previously an exclusive property of the radio amateur licence. With amateurs unnecessarily constrained to use known modes and speech bandwidths, the ubiquitous telephone datacomms Internet (INet) consumer service delivers the "final blow".
Historically amateur radio flourished when it tacitly offered the newcomer miraculously advanced "science-fiction" capabilities, undreamed of by the public. Today amateur radio stays narrowly confined by government agents, whilst consumer radio operators of comparable products are allowed previously unimaginable freedom. Though for our sins we were regular radio appliance users long before the public.
What's left for the amateur is use of pathetically obsolete, foolishly rule-bound simplex communications. AMATEUR Radio needs to be re-definednotwith the previous narrow-mind-set of petty-officiousness, but in terms of it being a quality agent of continued scientific & technical innovation, invention and change: A popular technology furthering recreational, educational and social communication media entirely free of exploitative tolls and commercial profit.
Unintentional government obstruction of (amateur scientific & technical) innovation needs to be acknowledged and cleared away to allow it to flourish. Amateur Radio basically needs innovation or (it will inevitably slip away into) oblivion.
The obvious (and topical) step forward is to "go digital".
By developing broad band wireless microwave datacomms repeaters we can win back "science-fiction" capabilities for 10 or 20 years ahead, such as free world-wide handheld fast scan videophone conversations, VR sites, community research & knowledge environments, interactive systems, tele-presence & handling, tele-tourism, tele-field-trips, tele-junk-sales, tele-instrumentation, tele-repair-diagnostics, "local Community INet Radio & TV Broadcasting", hand-portable/wristband video phones and television, (VR) group activities.
Being able to offer wired network LAN speed/bandwidth is a superbly attractive notion. To provide amateur wireless Microwave Datacomms Repeaters at speeds associated with LANs is even better. New products are available for the consumer, offering (without amateur radio licensing) the exciting possibility of new community wireless datacomms repeaters, run by non-commercial network service providers with Toll-free Open Access. The frequencies allocated are on part of an existing U.K. amateur band where this technology may be used by us "off the shelf" or power and range boosted or adapted for the wider choices of channels and bands available to the licensee. Amateurs still have enormously large upper microwave bands suitable for delivering communications throughlicensed Amateur Radio Microwave Datacomms Repeaters. It is possible to build these at 100 or 1000 Mbps for realising any future national amateur "microwave repeater super highway" to interlink the presently proposed small scale local amateur wireless data networks.
The new 10Mbps WLAN option allows local hi-speed amateur radio repeater intranet access at low cost and with affordable hardware adaptations with or without amateur radio co-operation.
In parallel with any kind of amateur WLANs comes the possibility of Digital Networking of VHF & UHF voice repeaters whereas a 10Mbps or faster digital network can carry the digitised audio of scores of repeater channels and enable say "touch tone dial up" of distant compatible repeaters.
A small repeater group can start today by operating a single Local Area Network (LAN) Server computer system as a dial-up Community Network Server providing at very low cost an ideal standard of publishing, mail-outs and inter-communication services required of a local group.
Given INet and 2.4GHz Public WLAN compatibility a "Community Network Server" can eventually support basic Amateur Radio Repeater Internet Services.... leading in its advanced conceptual form to the means by which amateur radio can offer its members speed and service way beyond that of ordinary business and private customers so that it is once more able to tacitly offer the newcomer fantastically advanced and miraculous "science-fiction" capabilities.
Hi-speed Amateur Radio Repeater Internet Services
hardware & costs
Equipment inventory for a pilot system
Glossary of terms and abbreviations
Despite the best efforts of our national and local societies and exceptional input from loyal and committed volunteers and enthusiasts, amateur radio activity in the Mendip area (here as elsewhere) appears to be in serious decline. Membership continues to fall. Interest is waning. Reported activity on the bands is much down and we must expect to lose more sites and frequencies.
In response we might routinely cut costs, attempt to recover lapsed members and recruit more new members. There is general support for the (national) RSGB led strategic measures for encouraging more new radio amateurs....... but attempting to interest anyone (particularly an intelligent and busy youngster) in amateur radio is an uncertain prospect.........
For 60 years a "mentoring" radio amateur could be effective just by loaning a few tasty magazines and support of constructional projects. Ten years ago the loan of an old portable RX for the local repeater might do the trick, but as several commentators have noted now "it just doesn't cut it" anymore.
Even having persuaded the busy youngster to complete the lengthy process of study, formal examination and station building, once licensed their interest might then only last a few months.
These should be matters of serious concern
for everyone engaged in organisation and administration of
amateur radio, requiring immediate attention and urgent remedy.
HIGH STREET COMPETITION
For the £60 price of a modest second-hand rig, a child or youngster, can get a licence exempt, pay-as-you-go-cell-phone with 2 months receive and £15 worth of world-wide calls. If possessed by a reckless need to converse with strangers, s/he may use it at any time to join a variety of telephone "chat channels" or start a CB net.
Given almost certain access to the World-Wide Internet (INet) at school or college, s/he now has access to a million lifetimes study of documents, prose, pictures, images conferences and increasingly music and relayed radio & TV broadcasts. Any modern Internet user can now add a two-way INet voice and videophone kit for instant one-to-one or conference video conversations to anywhere in the world. While amateurs are artificially constrained to use only "known modes" and "speech bandwidths, this ubiquitous telephone Internet availability offers us the final "knock-out" blow.
In that amateur radio now has such
little appeal is obvious enough but it's not a problem local to
the Mendip district nor even to the U.K. as these factors (in
keeping with the times) operate globally.
When domestic telephones were still a luxury, amateur wireless engineering enthusiasts brought "science fiction" into fact, pioneering wonderfully exotic and advanced two-way (mobile and fixed radio, facsimile, radio teletype, data, video) world-wide communications.... all toll-free.
Amateur wireless engineering enthusiasts (the divisions into "software" "audio" "electronics" and "digital" did not occur until fairly recently) had the first home-made electric gramophones, intercoms, car radios, TV, hi-fi & FM stereo, electronic keyboards, tape recording systems and video cameras. In the 1970's, amateur electronic enthusiasts were natural microcomputer pioneers.
For many years amateur radio casually accepted its ability to attract newcomers with the exciting prospect of operating and building marvellous communications systems of far superior performance than any available to the general public.
From the mid 1960s amateurs were however
increasingly weaned on becoming "consumer operators"
of factory built "radio appliances".
Cartoon #1 : Blubbering baby in cot reaching out with both arms at surrogate "bottle" handi-talkie.
Caption: .....amateurs... increasingly
weaned on... radio appliances.
Today's licensed amateur radio operation hasn't anything especially wonderful to offer. Any consumer can now become a "consumer operator" too just by buying a radio (CB or cell phone) plus any extra (vehicle adaptation kits, facsimile, datacomms, Internet voice and videophone) features made available.
By a somewhat quirky consequence of de-regulation, "consumer operators" now enjoy a much higher quality use of transmitter equipment than we ever did! By default, unlicensed operators have been allowed the following greater freedoms explicitly prohibited to licensees:-
Third Party Traffic
No Call Signs. No log keeping
Recording & re transmission
Broadcasting General Information & Music (QRP)
Voice Mail and mail boxes
Infra-red Comms (prohibited under the 1949 Act.)
Wireless Headsets & Wireless Mics
Cross-Band & Duplex working
Wireless Remote Presence
Automatic Network Identification
facilities earned by amateur operator qualifications (compared
with "consumer operator" privileges as listed above)
a) Competition on tiny internationally agreed HF bands with strict use of obsolete or extinct simplex operating modes such as RTTY, AMTOR, MORSE CODE, AM, SSTV & SSB.
b) Licence for experimental amateur construction and use (much under- valued).
c) Installation & toll-free use of unattended communal radio repeaters.
d) Use of huge locally approved VHF, UHF &
If amateur radio users are to continue as
little more than a "competitive type of consumer
operator" the technical, morse and licence conditions
exam might well be abolished where not relevant.
RE-DEFINING AMATEUR RADIO
Part of the problem is the habitual acceptance by us today of the above self-limiting definitions of AMATEUR Radio. These are obsolete restrictions produced from an old fashioned, narrowly mechanistic and linear (cold-war governmental) mind-set, rather than from a modern expansive, recreational, educational & social cultural ethos.
A need for a more liberal, rejuvenated and
"future proof vision" is surely "The Big
Issue" now facing Amateur Radio......which needs to be re-defined
not in the past behaviouristic terms, but in terms of it
being a quality agent of continued scientific & technical
innovation, invention and change: A popular technology
furthering, open, recreational, educational and social
communication media entirely free of exploitative tolls and
GOVERNMENT OBSTRUCTION OF INNOVATION
Before making improvements, we must come to terms with the unintended stifling hand played by bureaucratic regulation on amateur radio.
It may be this alone (or vested interests in organised compliance and our own complacent apathy) which has obstructed amateur radio from leading the way in advanced recreational, educational and social communication media which are not only better and faster than anything available to the general public but entirely free of exploitative tolls and commercial profit.
As implied above, the greater freedom enjoyed by untrained and unlicensed "consumer operators" as a result of deregulation in the public radio environment makes acorresponding failure to deregulate amateur bands above 30MHz thoroughly inequitable and indefensible.
Government obstruction of amateur scientific & technical innovation must be acknowledged and cleared away to allow amateur radio to flourish.
But even if amateur radio should fade away into
technical decadence and oblivion, old time amateurs might take
some comfort in the fact that "everyone is a world-wide
two-way radio user now".....
"INNOVATION OR OBLIVION"
Amateur radio as a scientific and technical
hobby resisting major changes will not survive much beyond
the present generation except as an increasingly eccentric and "retro"
atavistic hobby interest comparable with the love of
wooden sailing boats, antique machinery restoration or running
old steam traction and locomotives.
Cartoon #2 : Any picture of mega hi-tech restoration project (e.g. old Saturn 5 moon rocket, Jodrell Bank Observatory or say a Nuclear Power Station).
Balloon caption from inside: (Mmmm.......sounds good enough to
It takes only a small number of right thinking amateurs who support pioneering technical progress to undertake suitable remedial activities which might be generally adopted everywhere else. It is now feasible to offer members of large amateur radio groups such as ours (with over 800 listed members), considerably enhanced Repeater Services based on the marvellous synergy of combining VHF, UHF and microwave repeaters, wireless TCP/IP, server, telephone lines and the World-Wide Internet.
The Digital Option is a realistic & practical strategy, "old hat" in almost every other communications field)...... which will if nothing else enable us for a decade or two to "attract newcomers with the exciting prospect of operating and building marvellouscommunications systems of far superior performance than that available to the general public."
Digitisation can allow us to once more offer "science-fiction" toll-free, wire-free capabilities. Consider the options of - world-wide fast scan videophone conversations, VR sites, community research & knowledge environments, interactive systems, tele-presence & handling, tele-tourism, tele-field-trips, tele-junk-sales, tele-instrumentation, tele-repair-diagnostics, "local Community INet Radio & TV Broadcasting", hand-portable/wristband video phones and television, (VR) group activities.
The low cost of computer hardware of just a few
years age and modern plug in analogue to digital cards for both
video and multi-channel sound, with (the even more applicable)
"Internet Phone" & "Internet Videophone"
plug-in kits make the interfacing of analogue repeaters to a
digital network structure well within the amateur experimenter's
Anyone experiencing the response times between a computer terminal connected to a LAN socket at several Mbps with one connecting via a PSTN modem even at V.90/56Kbps soon appreciates voice bandwidth limitations.
Most datacomms users however will be stuck with voice bandwidth telephone data modems for many years until commercial broad-band microwave, co-axial cable or optical fibre is "everywhere on the streets" and will then certainly have to pay dear for it at "whatever price the market (their pockets) will stand".
An alternative for enthusiasts will be
"mega-stream microwave amateur repeater networks".
The use of the upper microwave frequencies are essential in order to offer the mega-bandwidths necessary to carry data transfer at reasonable network speeds such as required for several channels of amateur and broadcast radio and television and large amounts of simultaneous high speed ISDN type traffic.
Currently an individual user with (3KHz
packet-radio and phone-modem bandwidth) would be well satisfied
by a client servicing bandwidth increase of X 1000 to around 1-10
MHz, with a local network running at 10-100 MHz. This
satisfactory performance will inevitably require increasing over
Toll Free, Open Access
Licence free, secure, spread spectrum, 10Mbps wireless networks for everyone!
Whereas amateurs seem happy to put up with being stifled and confined to "antique speech bandwidths" not so the man in the street! The consumer market is more modern and progressive. People want all sorts of things mobile and networked and as with CB, what consumers want and need, they seem to get anyhow. The spin-out from this is low cost microwave networking products.
The recent IEEE 802.11 International Standard for 10MHz WIRELESS LOCAL AREA NETWORKS (WLANS) gives international-licence-free-public-use of up to 10Mb/sec Direct Spread Spectrum Wireless "Ethernet" on each of 8 channels within what is currently only the upper half of our U.K. Amateur 2.4 GHz (13cm) ISM band..... This offers best data rates some 80 times faster than present best V.90 and ISDN telephone line services and some 1000 times faster than the best 9600 baud voice-bandwidth AX25 Amateur Packet Radio!.
IEEE 802.11 is embodied in chipsets (and a ready-made PCMCIA plug-in card) delivering a complete QPSK spread spectrum WLAN single antenna transceiver system (Harris Semiconductors $100 for a set of 5 chips with low cost domestic alternatives perhaps as cheap as $30 per set appearing very soon).
Given the proven abilities of amateur kit suppliers and purchasing concessions etc, we could easily implement individual microwave links using these at much less cost than the real cost of an old AX25 packet TNC and transceiver node.
A current HARRIS 250mW PA & antenna-change-over-switch chip (with a specified barefoot monopole range of 1km) fed to ex-DBS 1 metre dishes (despite their reduced gain at 13cms) offers some 150Watt ERP (a trifle adequate perhaps for all clear-weather line-of-sight terrestrial paths).
With linear signal processing we might
translate the network physical layers to and from any
other amateur microwave band where we can mix, filter and amplify
to a few hundred milliwatts or so (10GHz the favourite due to the
residual amount of DBS kit available).
AMATEUR RADIO MICROWAVE DATACOMMS REPEATERS
In addition to band space for 8 more identical channels directly below the public 2.4 GHz WLAN BAND, licensed radio amateurs have access to immense microwave spectrum elsewhere where transmission links of 100Mbps or even 1000Mbps are quite feasible (for any future national amateur "microwave repeater super highway" to interlink the proposed small local amateur wireless network servers - see below).
Applicable, low cost and effective microwave ATV transceiver technology has been around on a number of bands between 1.3 and 22 GHz for over 10 years. However amateurs using datacomms have not used this for broad-band data links yet. (Apparently because of lacking a suitable common standard).
Due to line-of-sight paths and the economical use of high gain and highly directional dish antenna with low power, the topic of amateur microwaves seem inseparable from (and very little will ever be done by amateurs on microwaves without) Microwave Repeaters.
The "new unrestricted public 2.4GHz WLAN
band" sits on the commercially neglected water absorption
spectral line and domestic microwave cooker frequency of 2.45
GHz. Enthusiasts have successfully converted cookers to produce
several hundred antenna watts of tube modulated amateur TV for
Cartoon #3: Spoof Small Ad.
Community TV Transmitter
Be the first boy or girl on your block with a 1000 Watt TV station!
Make many new friends and
impress others. Build it for under $100 using mum's old microwave
cooker! Home constructional plans. Send $12 and large SAE to The
Hon. Sec. Mendip Repeater Group, PO BOX 73, WELLS, Somerset, BA5
By choice however we might plum for a comprehensive geographical presence on all channels in the "Public 2.4 GHz WLAN BAND" with IEEE 802.11 compatibility to permit participation by a potentially huge future membership of no-licence-required valid new repeater group subscribers (e.g. our family & friends).
The IEEE 802.11 spread spectrum modulation
considerably reduces co-channel interference on a band where even
when very densely populated, our anticipated use for uplinks of
high gain, narrow "pencil" beamwidths, fixed dish
antennas, would anyway give us a high order of immunity. While
this is just one of many possible microwave radio digital network
concepts, the common Open Standard Interconnection ethos of
network connectivity make this potentially common and low-cost
standard, the most favourable existing candidate for entry
level user uplinks.
DIGITAL NETWORKING OF VHF & UHF VOICE REPEATERS
When phoning someone in distant London, my voice is instantly "digitised" at my local exchange, digitally switched, routed and relayed by microwave radio and cable links in a mega-stream of digital packets to his/her local exchange where they are sorted and reconstituted as analogue speech. Only the handsets and physical cable connections to the digital (subscriber line duplex codec) interface at the exchange remains analogue.
Similar digital networking is applicable to VHF/UHF repeater users because after the initial VHF & UHF radio uplink to a communal repeater site, a low cost PC system can convert both audio input and output into internet compatible digitised audio packets which can be block transported and faithfully re-constituted for re-transmission at any compatible distant site, potentially anywhere in the world. Just as I can (and do) still use a selection of ancient black telephone handsets on my modern digital exchange, so amateurs could continue to use "ancient black box rigs" to access "VHF/UHF speech ports" on a digital repeater network .
The principle advantage of digital networking like this for a repeater group is that the "repeating" need not always be made from a single prime site, allowing our service area to be covered using a flexible voice repeater network which meets geographic and topographical requirements.
An initial 10Mbps digital network can carry
1000 or more simultaneous, digitized amateur speech channels so
the facilitation of existing two-way voice communication
over a digital repeater network constitutes only minor traffic.
LOCAL AREA NETWORK (LAN) SERVER
A local amateur group like ours with big ideas but limited funds, limited resources and too few willing hands means that in "thinking globally but acting locally" we must use an incremental implementation methodology. We cannot digitise our audio repeaters without a high capacity toll-free digital network to interface them with.
We can however make a start with just one Network Server (a small computer, tower size upwards, built for reliability, multitasking and continuous running).
One or more (1 + 1 backup) provide a key component from which strategic network services may be evolved at the lowest cost.
Building our own server means that we can
therefore immediately begin to start to "grow" our own
Mendip "Amateur Radio Repeater Digital
COMMUNITY NETWORK SERVER
Giving attention to secretaryship and administration of a local group mandates one to look into the mechanics of how it is done. It's been a mystery to me for 20 years why amateur radio administration & organisation has not been clearly at the fore-front of the "communications and IT revolution" and particularly lagging behind in the use of its own wireless datacomms for electronic publications and newsletters and the use of local nets for local club business.
The ongoing administrative needs of this local amateur radio society (ARS) of several hundred or more members paying only token subscriptions is sufficient argument for me "to put the pudding to the proof" in making the first practical incremental steps at evolving a local digital network in the form of a pilot LAN Server. This is a modern version of the traditional Computer Bulletin Board (BBS), which while permitting anyone with a computer and modem built during the last 20 years to log in using basic ASCII Teletype command line/menu access can also properly service fast V.90 (56Kbps) or 10Mbps WLAN network speed Microsoft Windows Explorer or Netscape Navigator GUI clients.
With a low cost periodic dial out INet connection, within the context of the server making regular off-line outgoing local calls to its own multi-address Internet Access Provider (IAP) ARS members will be able to send and receive Internet E-MAIL and NetNews under their own callsign / handle for E-MAIL.
New visitors and non-ARS members may be permitted to call in to exchange local E-MAIL, queries, download new member info, meeting invitations, download study modules for the two radio exams and even make donations and pay subscriptions using a credit card.
Being an amateur radio project, simple AX25 packet radio could facilitate 1200/9600 packet connections were this legal.
Use of hyper-speed 10Mbps QPSK WLAN connections
to our Server on this portion of the 2.4GHz (13cms) amateur band
would contravene the amateur radio licence conditions for
licensed amateurs, but not ordinary people....!
Cartoon #4: Spoof System Warning Message.
Mendip (Amateur Radio) Repeater Group
Hyper-speed WLAN connection to our
Free Public Internet Server on this portion of the 2.4GHz (13cms)
amateur band is prohibited for all amateur radio licence
For our immediate purposes, equipment of 5
years vintage, discarded by the trade as obsolete (cost
under £500) will get us started. Initial planning must allow
that at some time in the future we would transfer to a WLAN
Server with 24 Hour real-time INet
AMATEUR RADIO REPEATER INTERNET SERVICES
- hardware & costs
* A cheap end-user link. An ubiquitous and common uplink technology enabling each client computer to be "networked" at 10Mbps or more (to cost under £75 per user, using group supported home construction).
* A digital repeater & local WLAN server for the Mendip Local Network. (initially from £1000 inc. software & accessories)
* Fixed hill-top WLAN digital infill repeater(s) accessible by each member at over 10Mbps. (to cost under £150)
* Repeater ports for existing voice, packet and TV repeaters (under £150 per bi-directional audio or video channel)
* Inter-Network links to other networks (e.g. an Internet Gateway from £250 per year)
Inventory of services from:-
AMATEUR RADIO INTERNET SERVER
(with only periodic dial-up INet Connection):
a) Electronic membership services inc. "reference material" "journals" and "electronic newsletters" with options of a maintained but unattended "call centre" with PSTN "datacomms BBS" "voice-mail" and "fax- back" services.
b) All local ARS Members get INet E-Mail addresses. Can send and
receive E-MAIL and attached files.
c) Members can select personal interest topics of NNTP Net News and automatically download personalised selections on connection.
d) Local Members Electronic Wants, Sales & Swap forums
e) Computer File & Databases. Local Membership lists. Manuals. Data. Events. Contests. Circuits. Projects.
f) "Distance Learning" courses for Novice Licence, Morse Code Training, Radio Exams, Basic Theory, Shack & Equipment Safety.
g) Toll-free and licence-free public wireless access to Server beginning at 10Mbps (over 80 times faster than present best V.90 or ISDN landline services).
(The following only applicable if network server is "S9 +" with repeaters types specified)
h) Phone & modem monitoring of any INet programmed wireless voice/data or television media channel. e.g. Dial up to listen to local repeater while out of area. View local amateur television repeater outputs (as single frames).
i) Phone & Modem input to any INet
programmed wireless voice/data or television media channel. e.g.
Dial up and Talk through local repeaters while out of area. Send
images to local amateur television repeaters (as single frames).
AMATEUR RADIO INTERNET SERVER
(the above with additional real-time hi-bandwidth INet gateway:)
j) Toll-free and licence-free public wireless internet access beginning at 10Mbps. (licensees can be offered 100Mbps or more later depending on inter-network gateway limitations).
k) Toll-free world-wide hand portable INet videophone/remote imager
l) Toll-free world-wide hand portable INet telephone
m) Monitoring via INet of programmed wireless voice/data or television media channel. e.g. Listen to local repeater while out of area. View amateur television repeater outputs on INet.
n) Sending via INet to programmed wireless voice/data or television media channel. e.g. Using INet to work through local TV or voice repeater while out of area.
o) Interlink repeater workings to any
other INet prepared repeater (potentially anywhere on the INet).
Other miscellaneous services:-
p) Toll-free Amateur Text Message Paging
EQUIPMENT INVENTORY FOR A PILOT SYSTEM - example
1. Complete Tower PC "Green BIOS". 32MB or more RAM. 3GB HDD. 2. Mains Power Socket
3. Uninterruptible Power Supply (UPS)
4. 3GB plus back-up system
5. Relay card
Public telephone interface:
6. Internal or external Voice/Fax.
universal modems, data capable CCITT V21 thru to V.90
7. Telephone company line socket
2.4GHz Public WLAN interface:
8. Prime site (e.g. At Bath Univ. site for GB3UB, GB3UX-2, GB3UT)
9. 1 x PCMCIA card port
10. 1 x "Harris" PCMCIA "PRISM" (transceiver, modem & node card).
11. Antenna for 13cms: 15dBd omnidirectional (vertical polarisation)
(The following must be "receive only" given existing regulation)
Packet Radio interface:
12. 1 serial port, ( TNC and transceiver to work repeater if not co-sited)
Voice Repeater interface:
x "Internet phone" sound card with audio in/out sockets.
Use of relay contacts. (and rig to work repeater if not co-sited)
Television Repeater interface:
14. Two-way "Internet Video Phone" card with video in/out sockets.
(and amateur TV rig to work repeater if not co-sited)
15. Multitasking, Multi-user (Windows 95, NT4, Linux or better)
16. 4 node or more BBS/Internet Server (Wildcat! Internet Server, Apache)
17. WLAN card drivers (Harris Prism)
18. Sound Cards or Net-phone & Net-Videophone software (with cards)
19. Network Software (Novell NetWare, PC Net)
12. Repeater interface and system integration (custom patches)
GLOSSARY OF TERMS AND ABBREVIATIONS
ARS (Local) Amateur Radio Society affiliated to RSGB
ASCII Comprehensive 128 character set in 7 bit binary code
ATV Amateur Television (Fastscan, 625 line, 50 fps PAL)
AX25 Amateur implementation of X25 (ham packet protocol)
bps Bits/sec (approx. 10 times the byte or character rate)
CB Citizens Band
Codec Analogue/Digital Digital/Analogue coder/decoder
Co-operative Equitably shared control and ownership.
CW Carrier Wave (e.g. with Morse code communications)
DBS Direct Broadcasting Satellite
Duplex Simultaneous sending and receiving
E-Mail Personal datacomms ASCII messages
ERP Effective/Equivalent isotropic Radiated Power
Fax-back Automatic caller selected & initiated fax server
GUI Graphic User Interface (e.g. Microsoft Windows)
HAM American amateur radio operator
HF High Frequency 2-30MHz
INet World Wide Computer Datacomms Inter Network
Intranet Local Area Network with INet features and connection
ISDN Integrated Services Digital/Speech Data Network
LAN Local Area Network
Mendip Area served by West Region main TV mast: inc. parts Dorset, Somerset, Gloucestershire, Devon, Wiltshire.
Microwave 1000MHz upwards
NNTP Internet Net News Transfer Protocol
PSTN Public Switched Telephone Network
Prism Harris Semiconductors range of IEEE 802.11 products
Phone Patch Connection of radio system to PSTN
QPSK Quadrature Phase Shift Keying (bandwidth efficient method of data modulating RF carrier)
Repeater Automatic radio communications relay station
Rig Amateur radio transceiver
RX Radio Receiver
TCP/IP Transmission Control Protocol / Internet Protocol
TNC Packet Radio Terminal Node Controller (rig-to-datacomms interface)
UHF Ultra High Frequency 300-1000 MHz
VHF Very High Frequency 30-300 MHz
VR Virtual Reality (video, audio, movement interface)
WLAN Wireless Local Area Network