A long message is composed of multiple SMS messages. The long message will be split into multiple short messages and sent out. The receiving terminal is then responsible for reassembling the short messages and presenting them to the user as one long message. Each short message will start with a TP-UDH1 containing segmentation information (TP-UDH1 is set as 1). For Quectel modules, long messages can contain a maximum of 7 short messages