Wireless M-Bus Range Extender /
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User Manual Version 1.0
Page 16 of 32
Transport Protocol Details
The transport protocol is used in uplink- and downlink direction on several LoRaWAN® ports which indicate the type of message content.
The protocol uses a single octet header field with following format:
Figure : Transport Protocol Header
Last Segment Indicator (Bit 7)
This bit indicates the last segment of a transmission if set to "1".
Segment Number (Bit 0 .. 6)
The segment number starts at zero for every new transmission and will be incremented by "1" for every new segment. On receiver
side it might happen that duplicated segment number will appear. In this case the receiver should simply ignore the duplicate
segments. The segment number can wrap around from 127 to 0 in case of very large transmissions and tiny segments.
The following figure outlines a transmission consisting of four different segments and one re-transmitted segment.
Figure : Example transmission sequence with four segments and one retransmission
