Firmware update over the air (sometimes called FUOTA) makes it possible to
push firmware updates to one or multiple devices, making use of multicast.
It is standardized by the following LoRa® Alliance specifications:
LoRaWAN® Application Layer Clock Synchronization (v1 & v2)
LoRaWAN® Fragmented Data Block Transport (v1 & v2)
LoRaWAN® Remote Multicast Setup (v1 & v2)
It is important to note that the implementation of this feature by devices
is optional and therefore, unless your device explicitly states that it
implements FUOTA it is safe to assume it does not.
For a step-by-step guide how to perform a FUOTA deployment, please see
the FUOTA usage guide .
The following diagram provides a high-level overview of the ChirpStack
FUOTA implementation:
G start Start FUOTA deployment create_mc_group Create Multicast Group start->create_mc_group add_mc_devices Add Devices create_mc_group->add_mc_devices add_mc_gateways Add Gateways add_mc_devices->add_mc_gateways mc_group_setup_req Send McGroupSetupReq to all devices add_mc_gateways->mc_group_setup_req mc_group_setup_ans_wait Wait for McGroupSetupAns responses mc_group_setup_req->mc_group_setup_ans_wait mc_group_setup_ans_ok All acknowledged? mc_group_setup_ans_wait->mc_group_setup_ans_ok:n mc_group_setup_ans_ok:e->mc_group_setup_req No, retry if < max retries frag_session_setup_req Send FragSessionSetupReq to all devices mc_group_setup_ans_ok:s->frag_session_setup_req Yes / max retries reached frag_session_setup_ans_wait Wait for FragSessionSetupAns responses frag_session_setup_req->frag_session_setup_ans_wait frag_session_setup_ans_ok All acknowledged? frag_session_setup_ans_wait->frag_session_setup_ans_ok:n frag_session_setup_ans_ok:e->frag_session_setup_req No, retry if < max retries mc_class_x_session_req Send McClassBSessionReq -or- McClassCSessionReq to all devices frag_session_setup_ans_ok:s->mc_class_x_session_req Yes / max retries reached mc_class_x_session_ans_wait Wait For McClassBSessionAns -or- McClassCSessionAns responses mc_class_x_session_req->mc_class_x_session_ans_wait mc_class_x_session_ans_ok All acknowledged? mc_class_x_session_ans_wait->mc_class_x_session_ans_ok:n mc_class_x_session_ans_ok:e->mc_class_x_session_req No, retry if < max retries wait_mc_session_start Wait until multicast session start mc_class_x_session_ans_ok:s->wait_mc_session_start Yes / max retries reached enqueue Enqueue fragments wait_mc_session_start->enqueue frag_session_status_req Send FragSessionStatusReq to all devices enqueue->frag_session_status_req frag_session_status_ans_wait Wait for FragSessionStatusAns responses frag_session_status_req->frag_session_status_ans_wait frag_session_status_ans_ok All acknowledger? frag_session_status_ans_wait->frag_session_status_ans_ok:n frag_session_status_ans_ok:e->frag_session_status_req No, retry if < max retries cleanup Cleanup Multicast Group frag_session_status_ans_ok:s->cleanup Yes / max retries reached
