PAGER FREQUENCIES
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VHF-L

35.220, 35.260 - 35.540  .040 MHz spacing

35.580

43.220, 43.360 - 43.540  .040 MHz spacing

43.580, 43.620, 43.660

The 35MHz are the base side, and the 43MHz the mobile side when used as
IMTS/RCC phones. Mostly these are used for RCC paging now.

VHF-H

152.030 - 152.240 MHz  30KHz spacing  RCC

152.240 (P-5) is a common RCC paging channel.

152.480 PCP * Unofficial Nationwide Paging System *

152.510 - 152.840 30KHz spacing RCC (Bases)

157.740 PCP

157.770 - 158.070 30KHz spacing RCC (Mobiles)

158.460 PCP

158.490 - 158.700  30KHz spacing RCC (mobiles)

Again the 152MHz are paired with the 157/158 channels for IMTS/RCC phone
service where still used. Most are now used for one way paging.

UHF

454.025 - 454.650 RCC 25KHz spacing
459.025 - 459.650 RCC 25KHz spacing

IMTS/RCC phone service provided on these pairs using std. 5MHz split. Again,
where applicable,and now mostly one way paging. Some providers even use the 459
as links to other transmitters.

462.750 - 462.925 PCP 25KHz spacing Paging

900MHz

928-932MHz 12.5Khz spacing

Many nationwide systems like Mtel/Skytel, Mobilecomm, PacTel, etc.. are in this
area.


RCC = Radio Common Carrier
PCP = Private Carrier Paging

In the past a distinction was made for these 2 types of paging service. RCC's
could carry the publics traffic. PCP's were for company traffic and private
systems. PCP's & RCC's are now lumped together for paging. PCP's can carry
private and public traffic.


How Pagers Work
---------------

Several different systems are around.

Analog Formats

Two Tone Sequential - GE, REACH, Plectron, Motorola QCI(2+2) & QCII (1+1)
5/6 Tone - EIA and several European variants (uses different tones)
HSC
SECODE (Pulse)

Two tone is used commonly by FD/EMS to activate portable monitors (Mot. Minitor
I/II etc..)

5/6 tone is also a common PS format to activate tone only pagers. PSP uses
these on a statewide basis. They have very distinct sound. A tone then several
tones real quick.

Secode was/is used by many hospitals as a way to "dial" a hospital up for an
ambulance to notify of an inbound patient. Basically each hospital is given a
number, much like a phone number, and you punch this into a properly equipped
radio to send. This activates the radio at the hospital. Sounds like a tone
with pulse dialing occuring.

Digital

NEC D2
Motorola Golay both Numeric and Alphanumeric 300bps address/600bps data
POCSAG (RPC-1) both Numeric and Alphanumeric  512, 1200, 2400bps address/data
Motorola FLEX (NEW) supports speeds upto 6400bps

The analog formats use tones to send an address or capcode and the data.

Digitals use digital modulation to send the address and data, sounds like
screeching on a scanner.

Basically each pager has an address/capcode. When the person calls the phone
number given to that pager the system sends out that capcode and any message
applicable based on pager type, tone only, tone/voice, tone/voice/numeric,
numeric, or alpha.

POCSAG has pretty much taken over the digital formats right now. Look for FLEX
to be the next step due to the ability to send data at faster speeds, thus
carry more subscribers per channel/system and send more data to alphas.