what is the sending time delay between two parts of a single long SMS?

When we send a SMS longer that 160 characters then it is divided into small parts, and these parts are sent to the network in开发者_C百科dividually. Is there any standard sending time delay between such two parts of a long SMS. Also is there any standard time delay between receiving those parts at the receiving device? Thanks in advance...

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Handsets implement the queuing required to reassemble concatenated messages. The SMS parts, when delivered to the handset, include information such as total number of message parts and which part this message is. It's then up to the handset to do the reassembly.

As far as I know there's no required minimum or maximum time the handset is expected to honour between receiving parts, or even receiving all parts.

From experience I know that sending parts some hours apart can cause some handsets to do things like

• Drop the entire concat message
• Drop the late parts
• Display the late parts as individual messages
• Something else

I would suggest that you attempt to ensure you do not delay sending parts significantly. If you're using a GSM modem then quite possibly you should attempt to send the part sequentially without delay between parts.

All of this assumes you're sending modem PDUs rather than using modem AT commands. The AT commands of a modem may do different things, such as building the concat parts for long messages internally.

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They are simply sent as two separate messages; the sending mechanism doesn't care that they were originally one longer message. Various cellphones implement the sending queue differently, but in general I didn't notice any longer delay between the "parts" of a long SMS than between two unrelated messages. Same goes for receiving.

TLDR: the messages are sent and received as soon as feasible - so, there's no additional waiting loop, but usual network delays apply, especially if the network is under load (e.g. don't expect your message to be delivered immediately if you send them on Jan 1st right after midnight).