[VHF Pager Signals], [Special Amateur Digital/Video Modes] [VHF Selective Calling Systems] [VHF Digital Paging Signals] [VHF Two-way Paging Signals]
But...not all modes found on VHF are dedicated to paging, there are also systems used by the Aviation industry, the amateur radio community and some European Security forces/Police.
ACARS Aircraft Communication and Reporting System. A packet-
like 2400 bps PSK digital air to ground system for
passing plane data and messages.
Check the following frequencies in AM mode for signals.
131.550 (US primary)
130.025 (US secondary)
129.125 (US tertiary)
131.475 (Air Canada proprietary channel)
131.725 (Europe primary)
131.450 (Japan primary)
GMDSS/DSC DSC on VHF is the same as DSC on MF/HF except that the
system uses a 1200 bd and the packet is very short,
only about 0.5 sec. Frequency used is Ch. 70 -
156.525Mhz.
EMWIN Emergency Managers Weather Information Network is an
experimental data service, formerly known as WWIN
(Wireless Weather Information Network), run by the
National Weather Service that utilizes a 1200 baud
ASCII Bell 202 signal to transmit a hypertext system
(maps and text together) that lists weather conditions.
It is possible to reprogram some of the professional
units (such as the M7000) to receive the text infor-
mation, but special software is required to fully use
both maps and the text. Areas currently supported:
Location Watts Frequency MHz
----------------- -------- ----------------
Washington, DC 600watts 163.35
Norman, OK 50watts 169.025
Tulsa, OK 250watts 165.0125
Oklahoma City, OK 300watts 150.525
Wichita Falls, TX --- KTEO/90.5 FM
92kHz subcarrier
Note: the data is also transmitted from GOES 8, GOES
9, G4/Ku tr 4 and T1/Ku tr 5a.
FMS-BOS Funkmeldesystem fur Behorden und Organisationen mit
Sicherheitsaufgaben loosely translated as Radio
Calling/Communications System for Authorities and
Organizations with Security Concerns. Supports a
baud rate of 1200.
INFOCALL Supports a baud rate of 1200.
ATIS Supports a baud rate of 1200.
These modes can be found in the 6 meter (50 mhz), 2 meter (144-148
mhz), 220 mhz, 430-450 mhz ranges (70 cm.) and higher ranges. They are
primarily used by Amateurs, and some of them require special hardware
or software to view or use. These are capsule descriptions only; there
are several good books and magazine articles published in 'QST', '73'
and 'CQ' magazine which go into much more detail on these modes. Please
consult them for more information.
DSC 'Digital Selective Calling'. This is a system utilized
in the amateur service that allows suitably equipped
radios (such as those sold by Yaesu and Icom) to send
an ASCII burst signal that allows hams to page each
other by callsign over a repeater. It is somewhat
similar to POCSAG.
PACKET This mode is very similar to that found on HF, except
that a different tone set (typically Bell 202 tones)
are utilized. These signals can be found in almost all
the ham bands, including 900 mhz. There are 3 distinct
protocols in use here;
AX.25 Similar to that on HF, but speeds here are typically
1200 bd FSK or 9600 bd FSK or PSK in the UHF/SHF
range. Some applications using AX.25 are:
* Packet Cluster - This is a real-time networked mode
that allows connected amateurs to immediatly report
on DX stations and broadcast this information to
whomever may be connected. One of the most common
frequencies is 145.55MHz.
* APRS - somewhat similar to HF with different baud
speeds being used here. The national frequency for
this mode on 2 meters is 145.57MHz.
* TCP/IP - Transmission Control Protocol, Internet
Protocol. This mode, which uses AX.25 as the Link
Layer, is used, for example, in links between
Internet and amateur BBSs. Due to the nature of the
protocol and speeds used (9600 bd or better), units
like the M8000 will not read this data. However,
units with special software and firmware (such as
that found on the PK232) can utilize this mode. Units
operating in this mode are said to be in 'KISS' mode.
This traffic may be found on 2 meters on 145.59MHz
(and others).
ATV Amateur Television. This is a FSTV system used by hams
in the 430, 900 and 1200 Mhz systems. Uses include
public service and Space Shuttle relays. A special de-
modulator is required to see this system in most in-
stances; however, some cable TVs can also see this
system on channels 60, 62 or XX.
HSC Hexadecimal Sequential Code format is an analog system
introduced in 1979 that supports tone-only, numeric and
voice paging. It is based on the 5/6-tone system but
uses a total of 16 tones (0-9 A-F + Repeat). Selected
combinations of tones can be used to activate special
features built into the pager. HSC and 5/6-tone systems
can work together on the same frequency.
European 5/6-tone Systems
-------------------------
This analog paging format uses tone sets defined by various European and
United States standards organizations. This analog system uses 10 tones
plus one extra tone (in most cases) as a Repeat tone. The Repeat tone
is used when two tones representing the same number follow in sequence.
For example: 99222 would use the tone sequence 9R2R2. Pagers using this
format support up to 1 million pagers and support tone-only and voice
paging.
Tones supported are listed in the following as digit/frequency in Hz.
Also see Table 4-H.
+ EEA - SELCAL system conforming to Electronic Engineering Association,
United Kingdom. recommendations. Tones supported 0/1981 1/1124
2/1197 3/1275 4/1358 5/1446 6/1540 7/1640 8/1747 9/1860 A/1055
B/930 C/2246.9 D/991 E/2110 F/0 with a tone duration of 40ms.
+ CCIR 1 - CCIR 1 recommendations from Comite Consultatif International
De Radio. Tones supported 0/1981 1/1124 2/1197 3/1275 4/1358
5/1446 6/1540 7/1640 8/1747 9/1860 A/2400 B/930 C/2246.9
D/991 E/2110 F/0 with a tone duration of 100ms.
+ CCIR 7 - SELCAL system conforming to CCIR 7 recommendations from
Comite Consultatif International De Radio. Tones supported
0/1981 1/1124 2/1197 3/1275 4/1358 5/1446 6/1540 7/1640
8/1747 9/1860 A/2400 B/930 C/2246.9 D/991 E/2110 F/0 with
a tone duration of 70ms.
+ ZVEI 1 - SELCAL system conforming to ZVEI 1 recommendations from
Zentralverband der Electrotechnischen Industrie, West Germany.
Tones supported 0/2400 1/1060 2/1160 3/1270 4/1400 5/1530
6/1670 7/1830 8/2000 9/2200 A/2799.9 B/810 C/970 D/886
E/2599.9 F/0 with a tone duration of 70ms.
+ ZVEI 2 - SELCAL system conforming to ZVEI 2 recommendations from
Zentralverband der Electrotechnischen Industrie, West Germany.
Tones supported 1/2200 2/970 3/1060 4/1270 5/1400 6/1530
7/1670 8/1830 9/2000 A/2599.9 B/2799.9 C/810 D/886 E/2400 F/0
with a tone duration of 70ms. Also called DZVEI.
+ NATEL - SELCAL system conforming to Scandinavian National Telephone
(NATEL) recommendations. Tones supported 0/1633 1/631 2/697
3/770 4/852 5/941 6/1040 7/1209 8/1336 9/1477 A/1633 B/600
C/1995 D/2205 E/1805 F/0 with a tone duration of 70ms.
+ EURO - SELCAL system conforming to EURO recommendations. Tones
supported 0/979.8 1/903.1 2/832.5 3/767.4 4/707.4 5/652.0
6/601.0 7/554.0 8/510.7 9/470.8 A/433.9 B/400.0 C/368.7
D/1153.1 E/1062.9 F/0 with a tone duration of 100ms. Also
referred to as EuroSignal
Motorola Systems
----------------
+ EIA - SELCAL system conforming to Electronics Industries Association,
United States (EIA) recommendations. Tones supported 0/600
1/741 2/882 3/1023 4/1164 5/1305 6/1446 7/1587 8/1728 9/1869
A/2151 B/2432.9 C/2010.1 D/2292 E/459 F/0 with a tone duration
of 33ms.
MODAT - Tones supported 0/637.5 1/787.5 2/937.5 3/1087.5 4/1237.5
5/1387.5 6/1537.5 7/1687.5 8/1837.5 9/1987.5
REACH 11th root of 2
--------------------
High Freq - 0/2400 1/2253 2/2116 3/1987 4/1865 5/1751 6/1644 7/1544
8/1450 9/1361
Low Freq - 0/1200 1/1127 2/1058 3/993 4/933 5/876 6/822 7/772
8/725 9/681
+ CCITT SELCAL system conforming to CCITT recommendations. Tones
supported 0/400 1/697 2/770 3/852 4/941 5/1209 6/1335 7/1477
8/1633 9/1800 A/1900 B/2000 C/2100 D/2200 E/2300 F/0 with a
tone duration of 100ms.
+ VDEW SELCAL system conforming to VDEW recommendations or German
Electricity Works - Vereinigung Deutscher Elektrizitaetswerke.
Tones supported 0/2280 1/370 2/450 3/550 4/675 5/825 6/1010
7/1240 8/1520 9/1860 A/2000 B/2100 C/2200 D/2300 E/2400 F/0
with a tone duration of 100ms.
+ Hoka Code 30 can decode but needs the VHF option (extra) to decode
these modes.
POCSAG Post Office Code Standardization Advisory Group Pager
system developed in 1981 and is described in CCIR
Recommendation 584, Radiopaging Code 1. This system
can handle up to 2 million individual addresses per
carrier and can support tone only, numeric and text
pagers. Operates at 512, 1200 and 2400 bps (1200 and
2400 bps are commonly referred to as Super-POCSAG.
Transmits in FM Narrow using frequency bands that are
country specific. POCSAG is an asynchronous protocol,
it has a start up preamble signal that alerts the pager
to an incoming message (wake up). Pagers are assigned
to 1 of 8 groups based on address. Pagers only pay
attention to the address group to which they are
assigned. 2 coding formats are used for message text:
BCD and 7 bit ASCII.
ERMES European Radio Message System developed in 1990 by the
European Telecommunications Standards Institute.
Strictly a European format with no known US implemen-
tations. It supports alphanumeric, numeric and tone
paging. ERMES operates at a constant speed of 6250 bps
and uses 4 level FSK signalling. This protocol uses a
dedicated frequency spectrum in the 169 MHz range and
supports 16 adjacent channels. The pagers are designed
such that each pager is assigned to a specific time
slot and when the pager senses it is not in its 'home'
system it begins its roaming routine by scanning all
channels.
GOLAY Golay Sequential Pager Signalling System is a digital
system used to transmit tone only, numeric, alphanumeric
and voice pages. This is a Motorola proprietary system
but now obsolete according to Motorola. It may be that
GOLAY is no longer found in those VHF frequency bands
that support pagers but is still believed to be on US
Satellite.
Pagers are divided into groups and a preamble is sent
prior to paging alerts. Only pagers within the group
number sent in the preamble need to examine the data
stream for their address. Supports bit rates of 300 or
600 in that a pager address is sent at 300bps and any
numeric or alphanumeric information is sent at 600bps.
Also known as GSC - Golay Sequential Coding.
APOC Advanced Pager Operating Code. A new mode, developed
by Philips Telecom and announced in 1993, that offers
higher speed and some new features while retaining
backwards compatibility with POCSAG. Supports bit
rates between 1200 to 6400 or about 1200 to 3200 baud
using 2-PAM/FM or 4-PAM/FM modulation. Extended
addressing is supported, allowing support for more then
2 million pagers.
FLEX Paging protocol introduced by Motorola late in 1994 and
will be the protocol of choice as paging company up-
grade from POCSAG to FLEX in the US. FLEX supports rates
of 1600, 3200 and 6400bps and can handle up to 5 billion
addresses. FLEX has a 4 frequency signal arranged as
evenly spaced tones with usual shifts (in Hz) of:
-4800/-1600/+1600/+4800
This signalling technique is also more susceptible to
noise so a robust error correction scheme is incorp-
orated. FLEX pagers also appear to have a decreased
effective paging radius when compared to POCSAG.
FLEX is a synchronous time slot protocol. The FLEX
protocol does not send messages at random but instead
sends all paging data destined for a particular pager
during a pre-defined time slot. The pager only wakes
up only when a message is expected to arrive in real
time thereby saving battery life.
NEC/D3 A digital encoding format developed by NEC America that
supports tone only and numeric pages at a rate of 200
bps. This format was developed for use in NEC R3-D3
pagers. This format uses 2 methods for preserving
battery life. First a preamble is used to alert ALL
pagers that there are incoming messages. Pagers remain
idle till preamble detection. Second, pagers are
grouped by address into 1 of 4 different groups. Each
group is transmitted during a fixed time period and
pagers only power up to look for its own address during
the time its group is transmitted. Error correcting
codes and even parity bits are used on each address and
message.
Mark IV/V/VI A digital format that supports tone, numeric and voice
paging. This system requires 2ms to send a binary 0 and
4ms to send a binary 1 making the data transmission
rate between 250 to 500 bps. Mark IV could handle
tone only and Mark V and Mark VI could handle up to 10
digits.
Swedish MBS An FM subcarier system developed by the Swedish
Telecommunications Administration. This paging format
supports tone-only, numeric and alphanumeric paging.
Data is transmitted using the 57kHz subcarrier at a
rate of 1187.5 bps. MBS (Mobile Search) is used in a
modified form (MMBS) in the US by Cue Paging.
RBDS/RDS An FM subcarrier system developed by the Swedish
Telecommunications Administration. The system transmits
information to standard FM receivers using the 57kHz
subcarrier with a data rate of 1187.5 bps. A number of
features can be supported including: program id, alter-
nate frequencies, paging, clock/date and time and
travel announcements.
Reference the NRSC US RBDS Standard 1/8/93: Specifi-
cation of the Radio Broadcast Data System and the
European Standard CENELEC EN 50 067 (4/92): Specifi-
cation of the Radio Data System.
ReFLEX A Motorola two-way paging scheme. Currently comes in 2
forms. ReFLEX 25, which supports an outbound channel
capacity of 12,800bps and inbound capacity up to 9600
bps and ReFLEX 50, which supports an outbound channel
capacity of 25,600bs and inbound capacity up to 9600
bps. Both forms utilize a 50kHz channel. This scheme
is designed to give the end user the ability to ack-
nowledge a message, send replies and download data.
inFLEXon A Motorola two-way paging protocol that allows voice
and data messaging using a 50kHz Narrow Band PCS
channel with a throughput of 112K bps. This system
is based on the ReFLEX protocol.
NexNet A proprietary two-way system created by Nexus Tele-
communications, Ltd. of Israel uses Spread Spectrum
transmission from the pager to send responses. The
current system uses POCSAG to send messages to the
pager. Data sent outbound from the pager is transparent
to the incoming data which means that this two-way
paging system can coexist on pre-existing one-way paging
channels.
RAMP Radio Mail Protocol. A two-way pager protocol built
to be backwardly compatible with APOC. Currently
under development by Philips Telecom.
pACT An AT&T Wireless Services/PCSI developed open standard
designed to support two-way paging and messaging
services. The protocol uses an 8kbps link based on
re-use of cellular channels.
* POCSAG and GOLAY can also be found on U.S. domestic C/Ku-band Satellite
SCPC carriers.