Issue link: https://read.uberflip.com/i/1428383
LoRaWAN 1.0.3 Specification ©2018 LoRa™ Alliance Page 60 of 72 The authors reserve the right to change specifications without notice. 1570 Figure 27: Class C end-device reception slot timing. 1571 17.2 Class C Multicast downlinks 1572 Similarly to Class B, Class C devices may receive multicast downlink frames. The multicast 1573 address and associated network session key and application session key must come from the 1574 application layer. 1575 Example: [RPD1] provides an application layer mechanism to setup a 1576 multicast group over-the-air. 1577 The same limitations apply for Class C multicast downlink frames: 1578 • They are not allowed to carry MAC commands, neither in the FOpt field, nor in the 1579 payload on port 0 because a multicast downlink does not have the same 1580 authentication robustness as a unicast frame. 1581 • The ACK and ADRACKReq bits MUST be zero. The MType field MUST carry the 1582 value for Unconfirmed Data Down. 1583 • The FPending bit indicates there is more multicast data to be sent. Given that a Class 1584 C device keeps its receiver active most of the time, the FPending bit does not trigger 1585 any specific behavior of the end-device. 1586