Confusion about cellular solns

[Eric B.]

Hi,

I've been trying to understand how cellular communicators work, and I have
to admit, I'm a bit confused. From what I can tell from reading through the
docs on the different suppliers (ie: Teleguard, Uplink, etc), they
communicate via GPRS over GSM. Which sounds reasonable given that there
really isn't a whole lot of data to transmit.

But here is where I get lost. For any device to communicate over GSM, it
needs a SIM chip, which implies that every device would require a unique SIM
chip. Who provides the SIM chip? Does that come from the central station?
Does that also mean that every device have a unique telephone number? ie:
if I knew the number, I'd be able to call the device directly? How is that
profitable? The local companies here charge 15$/mth for cellular
monitoring. Assuming that the alarm system makes a verification phone call
every night to the CS, that would imply at minimum 30mins of usage a month
(assuming per-min billing) not counting any additional alarms. The cheapest
mobile phone plan I can find is $10 for 33mins. How can a CS offer a
service like this and remain profitable?

Am I misunderstanding how these devices work? Do CS's get such better rates
that the average joe consumer for his own mobile phone? Or do the CS's have
a huge GPRS data plan and all devices share the total calculated bandwidth?

I'm sure I'm missing something simple, but can't seem to figure it out...

Thanks for the info!

Eric

 

[Crash Gordon]

Uplink doesn't use a SIM card.

Only limited data is sent...not full signals by zone...troubles, restores
etc. Typically; Burg, Fire, AC Fail, Low Batt and weekly test, as such
doesn't cost all that much, and typically we don't charge all that much
extra since we are still monitoring and charging for the telco reporting.

I don't use Teleguard so cant speak to that.

 

[Eric B.]

Don't confuse cellular with cellemetry (I hope I spelled that right).

With cellemetry devices the radio uses the data channel of the cellular
network. It does not make a phone call. With cellemetry devices the sim
card comes with the radio. The radio does not have a phone number.

With cellemetry devices, the signal leaves the subscriber location via
cellular communications. The carrier, AlarmNet, Uplink or Connect24
forwards the signal to the central station. We receive our AlarmNet and
Connect24 signals via the internet, IP communications. AlarmNet calls our
receiver via telephone as a backup. Connect24 uses a second IP address we
get from another provider. We still receive our Uplink signals via
telepnone to our receiver.

I have not used a Tellular system but I understand this is a cell phone at
the subscriber location connected to the alarm panel. The alarm panel
dials
the central station via the Tellular device just like a regular phone
call.
I am sure this is how it used to work but it may be different now.

Wow - thanks for the info. Now I'm more confused than ever, however.

How do cellemetry devices know where to send their signal? Am I understand
this correctly that all cellemetry devices are tied to their manufacturers?
ie: they all transmit only to their own manufacturer's servers, who then, in
turn, need to forward the information to the Monitoring Station? So that if
I am paying 20$/mth for monitoring to my CS that i'll call Alarmco, my
Uplink/Alarmnet/etc will actually "dial" out to the Uplink/Alarmnet central
who will then, in turn, send the info over to Alarmco?

This many sound like a very newbie question, but how is the data connection
made, if no actual phone call is made? How does the receiving cellular
tower know where to forward the necessary information?

Given the variety of different cellular communication devices (Uplink,
Tellular, AlarmNet, etc), how does one choose the "right" one for their own
system/application? Or are they all essentially the same?

Thanks!

Eric

 

[Crash Gordon]

--
**Crash Gordon**

Wow - thanks for the info. Now I'm more confused than ever, however.

How do cellemetry devices know where to send their signal? Am I
understand this correctly that all cellemetry devices are tied to their
manufacturers? ie: they all transmit only to their own manufacturer's
servers, who then, in turn, need to forward the information to the
Monitoring Station? So that if I am paying 20$/mth for monitoring to my
CS that i'll call Alarmco, my Uplink/Alarmnet/etc will actually "dial" out
to the Uplink/Alarmnet central who will then, in turn, send the info over
to Alarmco?

Your alarm company programs the Uplink unit to route the signal to their CS.
It's sorta tied to Uplink yes. The signal goes from your house to the
nearest cell site then to their router (dunno if its technically a router)
in FL(?) then by landline to the CS...something like that.

This is not a DIY'er project btw.

This many sound like a very newbie question, but how is the data
connection made, if no actual phone call is made? How does the receiving
cellular tower know where to forward the necessary information?

Given the variety of different cellular communication devices (Uplink,
Tellular, AlarmNet, etc), how does one choose the "right" one for their
own system/application? Or are they all essentially the same?

No. Similar but different.

 

[Bob La Londe]

I have not used a Tellular system but I understand this is a cell phone at
the subscriber location connected to the alarm panel. The alarm panel
dials
the central station via the Tellular device just like a regular phone
call.
I am sure this is how it used to work but it may be different now.

Yes, and no. It does dial just like a regular phone, but it does not work
like a regular phone. The modern Telguard TG -X units take the data from
the panel, and then transmits via data channel just like other cell backup
units. It can be set at Telgurads center to either get the CS phone number
from the panel or to use a default CS number.