Hello,

I've _heard_ that cellular service providers leases a satellite
channel for transfer of sms messages and pay by the data rate passes
through.

I'd like brief clear information on the issue,
how do cellular providers carry sms messages throughout the world ? 
is there any _big_ corporation who does this regardless of a
providers' license ? is it a reasonable solution?
I'm refering to one way sending of the messages.

thats about it...

hackan-ga:

SMS messages are transmitted as data over a cellular service
provider's own wireless infrastructure, allowing their subscribers who
are equipped with SMS-capable devices to send and receive SMS messages
to each other. Where an agreement exists between two or more providers
to allow SMS messages from the subscriber of one service provider to
be sent to (and received by) a subscriber of another service provider,
the data is typically transmitted to an intermediary gateway (through
either a private data service, or through the Internet), which
performs any data protocol translations required before forwarding the
message to the network of the recipient, and ultimately to the
recipient's device.

The private data service or Internet conduit used to move
inter-network data packets around *may* be via satellite; however,
these days, there are cheaper alternatives to satellites for data
transmissions between many of the nations of the world. Within North
America, Europe, and many parts of Asia, fiber optic networks exist
that have higher capacity and cheaper transmission costs as compared
to satellites.

As far as big corporations go, the cellular service providers ARE the
big corporations as far as SMS services go. There are no licenses
needed for SMS itself, as the data rides on the same radio frequencies
and services that the service providers already have rights to through
their existing frequency licenses in the respective nations that they
operate in.

If there are any specific details that you would like to know about
how SMS' work, please let me know and I will see if I can provide that
information in the form of an Answer. Otherwise, I hope this Comment
helps you.

Regards,

aht-ga
Google Answers Researcher

Thank you for your comment,

Thats pretty much of an answer to my question, however it leads
several other questions as well. The reason behind my question is that
we're looking for alternative ways to lower our huge amount of text
messaging expenses by investing on a rather install-wise expensive
text message sending model.

In regard of your mentioning an agreement between providers, I'd need
a little clarification. Do a national X provider, gets in touch with
all other national/multinational providers to be able to send text
messages to other cellular service providers' customers and settle an
agreement?
Is there anything like a consortium where providers participate
without prior agreement made with each national cellular providers?
Or, when X settle an agreement with another national provider Y , does
X send it's messages to Z through Y since it hasn't got a direct
agreement with Z but Y does ?

Thank you,
hackan

You get charged for an SMS message either when you send it, or when
you receive it, depending on the pricing regime of your supplier. If
you happen to have a service plan that includes free text message
transmission, and the recipient has a service plan that includes free
message reception, then neither of you would be paying.

Text messages go from an originator's network, to a receiver's
network. They make the journey using a gateway. A gateway may serve to
connect multiple networks together, but at a minimum connects two
networks together. If someone on X wants to directly send a message to
someone on Z, then X and Z will need to have an inter-carrier
agreement in place first. If both X and Z have a relationship with Y,
but not with each other, then someone on X cannot send a message to
someone on Z. It's point-to-point as far as inter-network connections
go.

A consortium is simply another name for a group of agreements, where
each member essentially has a blanket agreement covering all the other
members of the same consortium. In North America, pretty much all of
the major carriers now participate in a consortium of sorts that
allows for text messaging between subscribers of different North
American networks. Similarly, the carriers in Europe have enough
agreements in place between each other to provide a similar effect.
Depending on the part of Asia or South America you're in, the same
holds true there. What does NOT hold true, is the ability to send a
message from a phone in, say, Asia, to a phone in North America.
Unless your carrier has an agreement in place with the network
operator of the receiving network, your network would not even know
where to begin routing the message, all it will know is that the
destination is not on the same network as you. If an agreement does
exist, then your carrier will have been able to configure its SMS
servers to recognize that a particular destination (area code and
prefix) belongs to another carrier, send the SMS to the gateway to be
relayed to the other carrier, and wipe its hands clean of any further
responsibility. Since your carrier controls whether or not an SMS
makes it to a gateway, you have no way to control it yourself. It's
very much a closed market, a monopoly.

Just to add a comment, if your operator has a gateway such as parlay
or etc, you can buy an SMSG "SMSM gateway" and link to them, without
paying for a lease or something, you'd pay pertransaction, however
this is not implemented all over the world.

and one more thing, SMS messages are carried over the signalling
channel which runs on standard interfaces all over the world, so a
sent message will be transmitted anywhere in the world as long as
there is normal telephony contracts betweeb the operators.. there is
no extra overhead in this process.

seems like sms is pretty much easy and cheap to carry(that is, once
the right equipment has been put in place). but the cellular operators
charge exhorbitantly for that (in India its about the same charge as
local call for one sms). if sms is carried over the signalling
channel, (and no voice channels are used), the intermediate switches
or SM points between the source and destination have almost no
controls over it. any idea how the charging takes place? i mean to
say, how do the telecom switches keep a count of how many sms's passed
through and on what parameters they have to be billed?