|
|
 |
|
|
|
register |
bbs |
search |
rss |
faq |
about
|
|
|
meet up |
add to del.icio.us |
digg it
|
|
|
|
Motorola mobile trunking system
NOTICE: TO ALL CONCERNED Certain text files and messages contained on this site deal with activities and devices which would be in violation of various Federal, State, and local laws if actually carried out or constructed. The webmasters of this site do not advocate the breaking of any law. Our text files and message bases are for informational purposes only. We recommend that you contact your local law enforcement officials before undertaking any project based upon any information obtained from this or any other web site. We do not guarantee that any of the information contained on this system is correct, workable, or factual. We are not responsible for, nor do we assume any liability for, damages resulting from the use of any information on this site.
%%%%%%%- MOTOROLA TRUNKING SYSTEM -%%%%%%%
This file is an over view of the Motorola Trunkin
system.
The concept:
Trunking is a means of having a large
amount of Two way radio users o few channels
without the bother of waiting for the other users
to clear a channel or as in convenioal repeaters
having all other users on that channel able
to moniter your voice traffic.
Interconec to the telephone lines available
as an option.This allows phone calls to be made
and recieved a wel as dispatch.
THE EQUIPMENT:
Trunked systems in the U.S. currerently
are all inthe 80 MHZ range with the systems being
repeater type systems. The main differences is where
to pu the lgic and control package and what type
of signalling system used.
The MOTOROLA system was dsigned ith the logic
in a central control unit located at the base
repeaters and a primarily digitl formatfor
signalling between mobiles and the system.
Data at 3600 baud is primarily used, also usd
is 150 aud and 3 tones (1800 hz,105 hz,and 163 hz).
Terms used:
For our uses we will uppose tha the user
is a rapid package delivery service with roving
supervisiors,roving expiditersstandard deivery
people and you the Boss.
FLEET: The entire group of mobile units and portables.
SUBFLEET: A ser defined section of mobiles,portables,
and or base units. A subfleet can be just thedelivery
peope and a base;or the Boss and his supervisiors or
any other combination needed. The moble units can b
fixed to one subfleet or be able to move between
subfleets.(number of subfleets acsesable by a singe
mobile can be restricted).
Up to 15 subfleets per fleet and numbers of fleets
are imited only by he number of channels in a system;
to a max of 20 channels with 305 fleets.
We wll now run throug a call on a basic system.
The system is 5 channels with one channel dedicated
to ata. Data channel s 3600 baud only.
When the mobile is turned on it scans for the
continuously tansmitted backgroun data stream.
this stream also contains the system Id.
The mobile if assigned tothis system will decde
the Id and sit on this channel. If a conversation
for this mobile is in progess then the mobile
dcodes the data and joins the in progress conversation.
When the mic button i depressed the mobile ends
on the data channel a request for service(known as
the inbound signalin word ,ISW.).
The ISW cntains the following information:
Fleet,Subfleet, and Unit ID.
The system ears the request and cheks all
channels for an activity. When it finds one
it sends back on the dat channel the following:
FEET,SUBFLEET,UNIT ID,AND CHANNEL INFORMATION.
This is known as an Outboundsignalling word,OSW.
The SW will send the mobile to a channel by
programming its synthesiser.If al channels
are busy the OSW ill cause a busy tone to
be heard and a busy lamp to light. The requestwill be held and the system ill call back
when a channel is available.
With the requesting mobile ow on the voice
channel the sstem still sends the OSW on the
data channel and sends a 3600 baud hanshake
on the voice channel.Thehandshake has Fleet,
Subfleet and Unit Id in it.
When the requestingmobile decodes the handshake
itresponds on the voice channel with 80 msec
of 1800 hz tone.This tels the system that it is
on the vice channel.
The system responds by changing the handshake
from 360 to 150 baud data using less devtion.
The 150 baud has in it Fleet and Subfleet data.
The system nw sends all other mobiles that arein the same fleet and subfleet to that voice
channel. When they arive they decode the fleet
and subfeet data and unmute the speaker to recieve
the voice message. OS still being sent on data channel
Te requesting mobile now switches to sending
the subaudable connct tone (105 hz) while voice
is beingtransmitted.
The system hears the connect tone and holds
the hannel for that subfleet.
When the reuesting mobile unkeys for the first
time it sends a 200 msec f disconnect tone(164 hz).
It also hear the 150 baud data and unmutes the speaker.
The disconnect one starts a time out timer in the syste.
All mobiles now on the voice channel may use the channel
Each time any mobile keys up it sends ony connect tone.
This tone tells the system that the channe is in use and
resets the time out timer.
When the conversations are done the timeout timer will
exire in the system causing a disconnect dataword to
be sent on the voice channel.This mutes the speaers
of all the units on that voice channel ad all
units return to the data channel.
The OSW on thedata channel is dropped.
The system will pu that fleet id in the recent
user queue.It will have frst call on the system
instead of a new reques by a different subfleet.
This is to ensure no waitin of a channel in the
middle of a voice message f someone lets the system
drop out.
This system hs a lot of nifty other features
including what Icall the Boss call and the
call from on high. As tis is long enough
already,I will save them for anther time.
If you have any questions leave a msg n the
forum in section 3 and I will be glad to giv you any
information I can.
JOE BARTLETT 70675,06 ALT.SYS.COMS.
|
|
|
To the best of our knowledge, the text on this page may be freely reproduced and distributed.
If you have any questions about this, please check out our Copyright Policy.
totse.com certificate signatures
|
|
|
About | Advertise | Bad Ideas | Community | Contact Us | Copyright Policy | Drugs | Ego | Erotica
FAQ | Fringe | Link to totse.com | Search | Society | Submissions | Technology
|
|
|
|
|
|
|
TSHIRT HELL T-SHIRTS
|
