Two Way Pagers.........How Do They Work?

[Johnny Galaga]

Do they use POCSAG or FLEX? What frequencies do they usually work on? How do you get the programming software and cradles? Is there a way to snarf capcodes?

[WPA6MDuplexer]

Do they use POCSAG or FLEX? What frequencies do they usually work on? How do you get the programming software and cradles? Is there a way to snarf capcodes?

When I was with PageMart (which became WebLink Wireless) the downlink (from base station) was in the 940 MHz area and uplink (to bse station) was in the 901 MHz area.

The over-the-air protocol that was used at one time was "ReFlex25" which is the 2-way version of "Flex".

Our competitors at the time used ReFlex50; a similar format with some differences.

See also "Description of a Narrowband NPCS Network" http://www.braddye.com/NPCSoverviewv4.pdf written by Allan Angus whom I had a chance to talk with when I worked there.

Here is a collection of stuff about 2-way paging by Brad Dye who is a former PageMart guy too: http://www.braddye.com/paging.html

I always got capcodes and such from the ops guys who handled the allocation of those things.

BTW, the 'capturing' of capcodes off the air is probably regulated by the Elec Pivacy act or some other statute; we used a specialized ReFlex25 box by Allen Telecom (at the time) for diagnostic stuff though.

[EEnerd]

I have wondered about this too. I played with a 'free lifetime news/weather/sports pager' that was a two-way model (actually it was a "One and a half way"- you can't send text back) and I guess we were in a marginal area, because when I turned off the two-way mode, there were lots of character errors in the maildrops. However when I turned the two-way transmitter back on, the pages came in just about 100%. So that means the pager was talking back (and re-requesting?) data. For some reason I found this pretty amazing. I'm suprised the tower doesnt request both a capcode and a MSN so that they can ignore/remotely deactivate cloned pagers like this.

As for snarfing capcodes, I've never seen any programs that claim to monitor the uplink portion.
Do two-way pagers talk back in FLEX or some other format??