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Bulk SMS

What Is Message Concatenation?
Concatenated SMS messages allow a phone to send messages longer than 160 characters. The sender composes a message normally, however, behind the scene, the phone detects the message length. If the message is less than or equal to 160 characters, the phone sends a one standard SMS message. However, if the message is greater than 160 characters, the phone automatically divides the longer message into multiple shorter SMS messages which are then transmitted to the recipient separately.

The recipient’s phone collects these multiple, shorter SMS messages and recombines them into the original message which was sent. Because the individual segments of the complete message need to be recombined in this way, this is referred to as ‘concatenated SMS’. In order to achieve this seamless delivery, additional information is added to each individual concatenated SMS message. This additional information, referred to as the user data header (UDH), provides identification and ordering information. For example, the UDH could relate the three individual concatenated SMS messages to each other, and indicate the order for recombination.

1.1. What is Character Count Thresholds for the concatenated SMS?
The character limits for individual concatenated SMS messages results in various thresholds for which additional individual concatenated SMS messages will be required to support sending a larger overall message:
GSM encoding:
1 standard SMS message = up to 160 characters
2 concatenated SMS messages = up to 306 characters
3 concatenated SMS messages = up to 459 characters
4 concatenated SMS messages = up to 612 characters
5 concatenated SMS messages = up to 765 characters
etc. (153 x number of individual concatenated SMS messages)

UTF-16 encoding (including special characters):
1 standard SMS message = up to 70 characters
2 concatenated SMS messages = up to 134 characters
3 concatenated SMS messages = up to 201 characters
4 concatenated SMS messages = up to 268 characters
5 concatenated SMS messages = up to 335 characters
etc. (67 x number of individual concatenated SMS messages)

These thresholds are an important consideration for a number of reasons including billing, and the programmatic interfacing with SMS gateways.
Generally, telephone companies count individual concatenated SMS test messages separately even though they are being combined at the phone into a single message.
This means a message containing 180 characters could potentially invoke a charge for two SMS text messages, even if the sender/recipient only sees a single message.
Dhiraagu bulk-SMS-short-code-messaging-service platform lets you choose up to the maximum number of concatenated SMS messages you would like to send. Note that if you send a message with more characters than the threshold limit, your message will be cut off. For example, if you send a message with more than 459 characters, but only allow up to 2 concatenated messages, your message will be cut off at 306 characters and the recipient will not receive the entire message.
What are the options to set in the ‘FROM’ field for SMS and IP?
2.1. Use my mobile number (7****** or 9******)
This is relevant only for users that hold mobile in their account.

2.2. Use a system allocated number (or my personal short/long code)

Recipients will be able to reply to these messages, and replies will appear in My Inbox. When we send the message, the sender of the message will be system number. Messages to the short code/system number will be considered as replies (and will be related as replies to last message sent).

2.3. Use a system allocated number. Delete recipients replies and don’t forward them to me.
When I use my personal short/long code, replies will appear in my Inbox. When we send the message, the sender of the message will be system number. Users with personal short code- messages to the short code will be considered as incoming messages (and will not be related as replies to previous sent messages). User without personal short code – messages to the short code will be dropped.

2.4. Use an Alphanumeric sender [open text entry field]. If not allowed – Use my mobile number (7****** or 9******).
When we send the message, the sender of the message will be the alphanumeric value. SMS messages with Alphanumeric can’t get replies. In case the provider we use doesn’t support alphanumeric-sender – we will use the user’s mobile as the sender (so replies will go back to the user’s mobile). In this case if we use override system number (like for bandwidth messages) – we will use system number but replies will be dropped. Note – in some cases we set the provider as alphanumeric supported but the provider itself override the alphanumeric and there is nothing we can do about this.

2.5. Use an Alphanumeric sender [open text entry field]. If not allowed – Use a system allocated number (or my personal short/long code)
When we send the message, the sender of the message will be the alphanumeric value. SMS messages with Alphanumeric can’t get replies. In case the provider we use doesn’t support alphanumeric-sender – we will use the system number as the sender. In this case if we use override system number (like for bandwidth messages) – we will use system number and replies will be stored in the user’s Inbox (and in some cases will be forwarded to the originator of the SMS). Note – in some cases we set the provider as alphanumeric supported but the provider itself override the alphanumeric and there is nothing we can do about his either.