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Philip Fagan
New member
Username: En1gma

Post Number: 1
Registered: 02-2004
Posted on Friday, February 20, 2004 - 08:09 pm:   

I'm a final year University student in Ireland. As part of my final year project I have to implement a home automation system. When an alarm goes off, my security camera will take an image and send it as a MMS through my GSM modem.
How will nowSMS aid this action??
Also, I have a J2ME application on my phone which will send commands to my GSM modem. Then in turn my Home Automation software will process these commands. Can I use nowsms as an interface between my home automation software and the modem, or will it be better just to use AT commands??

Thanks for help in advance
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 1916
Registered: 10-2002
Posted on Friday, February 20, 2004 - 09:39 pm:   

Philip,

You can send/receive SMS using AT commands. At a basic level, this is how NowSMS interfaces with a GSM modem to send/recieve SMS. But when it comes to MMS, things are considerably more complicated.

To explain this, let me explain a bit about how MMS actually works.

When a mobile phone receives an MMS message, what it is actually receiving is an MMS notification message which it receives over SMS. This MMS notification message contains header information about the MMS message, and a URL pointer that the recipient must fetch in order to retrieve the content of the MMS message.

So when you send an MMS from NowSMS, you can do this in one of two ways:

1.) Direct MMS delivery. The MMS message content is stored on the Now SMS/MMS Gateway, and the gateway publishes a dynamic URL for access to the MMS message content. The gateway generates an MMS notification message to the recipient device which is sent over SMS, and this notification includes a URL pointer back to the MMS message content.

2.) Send the message through an operator MMSC. We support all of the major MMS related protocols, including MM7, MM4, MM1 and EAIF for this purpose. But most frequently, what we see is the use of MM1 where NowSMS makes a GPRS connection over a GSM/GPRS modem, connects to the operator WAP gateway that is designated for MMS usage by the operator, and the message is submitted to the operator MMSC via the WAP gateway over the GPRS connection. (The operator MMS gateway then generates the dynamic URL and MMS notification message that is ultimately received by the recipient device.) In this scenario, NowSMS acts like an MMS client in a mobile phone would act.

The problem with approach #1 (Direct MMS delivery) is that the MMS client on every mobile phone is configured with settings for how the phone sends and receives MMS messages. To send or receive an MMS message, the phone makes a GPRS connection (to a GPRS APN), it then usually connects to the MMSC for sending/receiving messages through a WAP proxy/gateway. The pre-configured MMS settings on many mobile operator networks are setup to connect to a special MMS-only GPRS APN which connects to an MMS-only WAP gateway ... and this GPRS APN/WAP gateway is configured only to allow connections to the operator MMSC. If the recipient mobile phone is subscribed to an operator that has this type of setup, and you attempt direct MMS delivery, you can send the MMS notification to the phone over SMS, but the phone cannot retrieve the MMS message from your server because the GPRS APN/WAP Gateway does not allow it.

In those cases, the only alternatives are:

a.) Use approach #2, and submit the message through the operator MMSC.

b.) Change the settings in the receiving mobile phone so that it can receive messages from external MMSCs. (This is usually just a matter of changing the GPRS APN and WAP Gateway IP address that is defined for the MMS client ... change them to match the similar settings already configured for the WAP browser.) Note that in doing this, you may no longer be able to send/receive MMS through the standard operator MMSC.

c.) Use an altnerative to MMS, such as the multimedia WAP push function in NowSMS, where the multimedia objects are pushed to the WAP browser in the phone instead of the MMS client. (NowSMS can be configured to convert a submitted MMS into this format for delivery.)

--

I believe that in Ireland, both Vodafone and O2 do not allow messages from external MMSCs to be used, so you would encounter this direct delivery problem, and you would probably therefore want to route the message using GPRS over the GSM/GPRS modem to the operator MMSC.

The following link talks about configuring NowSMS for this type of connection:

http://www.nowsms.com/documentation/ProductDocumentation/mms_notifications_and_c ontent/Connecting_to_operator_MMSC.htm

And this link covers the APIs for submitting MMS messages to NowSMS:

http://www.nowsms.com/documentation/ProductDocumentation/mms_notifications_and_c ontent/Submitting_MMS_Messages.htm

There's a PHP script example for submitting an MMS message to NowSMS here:

http://support.nowsms.com/discus/messages/1/1113.html

And a Java example here:

http://support.nowsms.com/discus/messages/485/1360.html


-bn