Email to SMS - Max Length 160 chars??

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ash - 01 Feb 2006 20:31 GMT

I have a question on length limits for email to phone messages. Lets
say I send an email to my friend at 1234567890@tmomail.net (T-Mobile
email address) from any web-based client.
I was under the impression that any content over 160 chars would be
clipped.

But I was suprised to find that he actually did receive the whole
content (1001 characters to be exact). The content was split into 2
attachments within his email, each named "file.plain". I feel this is
wonderful since it costs the recipient only as much as a single SMS,
but with a lot more content.

I am wondering what the limits could be for other United STates
carriers (Verizon, Sprint etc). Thanks!

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John Henderson - 01 Feb 2006 21:15 GMT

> I have a question on length limits for email to phone
> messages. Lets say I send an email to my friend at
[quoted text clipped - 8 lines]
> recipient only as much as a single SMS, but with a lot more
> content.

Are you sure about being charged for only one SMS? I don't know
how your charging gets calculated, but a message with more than
160 characters is transmitted "over the air" as multiple
(independent, but "cross-referenced") SMSs. As such, I'd
expect a 161-character "message" to be charged as two SMSs.

> I am wondering what the limits could be for other United
> STates carriers (Verizon, Sprint etc). Thanks!

The generation of concatenated (multi-part) SMSs is a function
of the device which lodges them with the SMSC (short message
centre), not the carrier as such. That's because they leave
that device as, and are stored and delivered as, discrete
messages.

Because cross-referencing takes up message bytes that could be
otherwise be used for text content, the individual SMSs of a
concatenated message are limited to 153 characters each.
Unless otherwise restricted by particular equipment at the
sending end, GSM 03.40 permits a concatenated message to have
up to 255 parts. Reassembling it is a function of the
receiving device (not all can). Equipment in between neither
knows nor cares that the individual SMSs are parts of a greater
whole.

John

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ash - 01 Feb 2006 22:55 GMT

> Are you sure about being charged for only one SMS? I don't know
> how your charging gets calculated, but a message with more than
> 160 characters is transmitted "over the air" as multiple
> (independent, but "cross-referenced") SMSs. As such, I'd
> expect a 161-character "message" to be charged as two SMSs.

John,
Thanks for your informative reply. I do want to clarify a couple of
things though:

1. It costs the sender nothing in this case, since the sender is
sending the email from his web client, say Yahoo or Hotmail.

2. About the recipient, I wonder how TMobile can charge him/her for
receiving 'multiple' SMSs, since the phone actually displays: "You have
one new text message". Now can TMobile charge the recepient for 10 SMSs
even though the recepient thinks he opened and read only one message ?
I haven't talked to Tmobile about this, but I guess they cannot charge
for an arbitrary number of SMSs for what the user perceives as just one
email/text message.

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John Henderson - 02 Feb 2006 00:03 GMT

> 1. It costs the sender nothing in this case, since the sender
> is sending the email from his web client, say Yahoo or
[quoted text clipped - 8 lines]
> charge for an arbitrary number of SMSs for what the user
> perceives as just one email/text message.

Incoming calls and SMSs are free where I live (as they are in
most of the world), so I don't know the basis for the charging
of recipients.

It's the recipient's phone which knows that it has received one
message instead of two, because it's analysed the content of
the recieved SMSs, and unambiguously determined their
relationship. TMobile's SMSC won't be analysing the content of
messages lodged with it. If it's that lodgement which triggers
charging, then it will be charging for two messages.

John

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Simon Templar - 02 Feb 2006 03:14 GMT

> I have a question on length limits for email to phone messages. Lets
> say I send an email to my friend at 1234567890@tmomail.net (T-Mobile
[quoted text clipped - 10 lines]
> I am wondering what the limits could be for other United STates
> carriers (Verizon, Sprint etc). Thanks!

It sounds to me that the message has actually been recieved on the phone
as an email rather than SMS. There is NO way that 1001 characters can
be sent in two SMS messages.

--
73 de Simon, VK3XEM.

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John Henderson - 02 Feb 2006 03:18 GMT

> It sounds to me that the message has actually been recieved on
> the phone as an email rather than SMS. There is NO way that
> 1001 characters can be sent in two SMS messages.

Oops, I missed that bit of detail.

John

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