In 1.1, NbTrans governs both unconfirmed and confirmed traffic.
We cannot set number of retries ourselves. Based upon NbTrans received
in linkADRReq command, we will retry. If NbTrans is 1, we will send only
one message and if ack is not received we will generate TX error event.
Its the NS now which controls how many retransmission a device can do
without incrementing Frame counter. When we fail with TX error after not
receiving an ack, we increment the frame counter. This is necessary as
the NS will drop anything with the previous counter and it can happen
that the NS may have sent an ack but we didn't receive it.
Rejoin requests and presence/absence of CFlist demand different
handling.
If a Rejoin request was sent we shall use RJCountX (0,1) instead of dev
nonce for key derivation.
If a Rejoin request is not of type 2, we reset mac, phy parameters
alongwith frame counters. However, if it is type 2, we reset frame
counters only.
If cflist i present, we shall always apply it as it is.
If it's not and rejoin type is not type 2, we restore default channels.
Otherwise the local channels do not change.
LoRaWAN specification 1.1.0 is incorrect in handling of FOpts encrytpion.
A CR was made by STMicroelectronics which correctly addresses the issue.
We have taken that CR and implemented in our code base.
Although we always add a port field for Uplink traffic, the spec allows
for fport field to be excluded. So there can be network server instances
which would exclude fport field from downlinks. We are now adding
handling for such situations.
BE to LE fixes, missing MLME types added
LoRaWAN 1.1 Features added (Some LoRaPhy impl missing still + some TODOs in code)
- MLME confirm handling refactored
- Rejoin handling missing
- new CF_LIST mechanism missing (+resets involved)
- NVM handling missing
Rejoin logic added
_ongoing_tx_msg was incorrectly initialized before _mlme_confirmation.
Fixes following build warning:
[Warning] LoRaMac.h@691,26: 'LoRaMac::_ongoing_tx_msg' will be initialized after [-Wreorder]
[Warning] LoRaMac.h@689,28: 'loramac_mlme_confirm_t LoRaMac::_mlme_confirmation' [-Wreorder]
[Warning] LoRaMac.cpp@68,1: when initialized here [-Wreorder]
This prevents RX2 window to be enabled at the same time when repeating
transmission, when QoS repeated TX is in effect. Failure to do so
seems to place the LoRaWAN stack in a state where send() always fails
with WOULD_BLOCK error.
We provide now downlink channel frequency and time on air for the
received frame in the RX metadata.
Previously the channel information in both TX and RX metada contained
the index number of the channel. That information wasn't very useful
except the index numbers of default channels. To make more sense of the
meta data, we now store the channel frequency in the channel parameter
rather than the index number of the channel.
RX time on air is collected from the radio driver and it is assumed that
the downlink frame had 8 downlink preamble symbols (plus 4.25 of the
preambles added by the chip) for LoRa modulation.
This commit also include a bit of tidying of RX frequency storage in rx
configuration parameters storage. Previously we were missing filling in
the RX1 frequency correctly.
A bug while setting up RX start timers would result in premature closusre
of RX2 window. The 'ack_Timeout_timer' would be invoked prematurely and
at that time RX2 window may be being demodulating. This resulted in
massive instability with any test that relied on Confirmed traffic or
lower data rates.
To fix the issue, we must know the length of the RX window in
milliseconds and for this purpose we have extended the
'get_rx_window_params(...)' API. The length of the time the window
may remain open must be accounted for while setting up
'ack_timeout_timer'.
Previously we had been incrementing UL frame counter for a CONFIRMED
message only when the transmission was deemed successful i.e., we would
have received an ack before all the retries would have exhausted.
Now we have opted to increment the frame counter if all the retries are
exhausted considering the fact that we essentially treat the next
message after retry exhaustion as a new packet so we should also
increment the frame counter.
Previously, we weren't filling in RX1 frequecny in rx_window1_config
structure. However, everything worked as in LoRaPHY::rx_config() API
there was a check which filled in correct RX1 frequency.
Now we are filling in RX1 freq. properly while we are computing
parameters for RX1 window.
LinkADRReq mac command can be used by the network server to set a
certain level of QOS using NbTrans field which is applicable to
Unconfirmed traffic only for 1.0.2 spec.
This commit introduces mechanisms to facilitate this QOS. It means to
repeat an outgoing unconfirmed message NbTrans times without changing
its frame counter.
For class C, we have retired the ack_expiry_timer_for_class_c and have
replaced it with another timer which mimics the RX2 closure as in Class
A but doesn't actually close RX2 window. It's just a mechanism by which
the state machine is informed that the you can proceed forward, we have
not received anything in RX2 window either. This is needed as RX2
doesn't timeout in class C (i.e., the radio remains in continuous mode).
In addition to that we need to close any pending timers for Receive
windows after the MIC has passed and the Duplicate counter check has
also been passed.
If the packet is already handed over to the PHY layer, we shouldn't be
able to cancel that particular transmission. In addition to that if the
backoff timer is either not applied or has been deactivated, should end
up in no-op rather than having normal termination. A new error code has
been introduced to cover no-op cases. This error code replaces the
compliance test related error code which is no longer relevant.
clear_tx_pipe() does nothing if:
- The stack cannot cancel TX (already handed over to PHY)
- The backoff timer is not active at all
- The event is disaptched to schedule
stop_sending() will only post process ongoin TX if the pipe was
definitely cleared.
Previously, we weren't filling in RX1 frequecny in rx_window1_config
structure. However, everything worked as in LoRaPHY::rx_config() API
there was a check which filled in correct RX1 frequency.
Now we are filling in RX1 freq. properly while we are computing
parameters for RX1 window.
LinkADRReq mac command can be used by the network server to set a
certain level of QOS using NbTrans field which is applicable to
Unconfirmed traffic only for 1.0.2 spec.
This commit introduces mechanisms to facilitate this QOS. It means to
repeat an outgoing unconfirmed message NbTrans times without changing
its frame counter.
For class C, we have retired the ack_expiry_timer_for_class_c and have
replaced it with another timer which mimics the RX2 closure as in Class
A but doesn't actually close RX2 window. It's just a mechanism by which
the state machine is informed that the you can proceed forward, we have
not received anything in RX2 window either. This is needed as RX2
doesn't timeout in class C (i.e., the radio remains in continuous mode).
In addition to that we need to close any pending timers for Receive
windows after the MIC has passed and the Duplicate counter check has
also been passed.
While performing compliance tests with an industry tester, we realized
that there was no need for any extra handling code for the compliance
tests. The tests would run fine, if we only have a handling application.
However, in normal operation we wouldn't like the network to send us any
traffic on compliance testing port. To mitigate that, on the reception
path we filter out any traffic on compliance testing port if compliance
testing is not underway. User should define LORAWAN_COMPLIANCE_TEST macro
in mbed_app.json to enable traffic on compliance test port.
This commit fixes two bugs related to ADRAckReq:
- adr_ack_counter must be incremented for all uplink messages (not just confirmed)
- When ADR_ACK_LIMIT + ADR_ACK_DELAY has been reached, stack decreased used
datarate twice.
- Duty cycle can be now only disabled with duty-cycle-on flag if region supports duty-cycle.
If region does not support duty-cycle, this flag has no effect and duty cycle is always
disabled.
- Also introduced a new flag (duty-cycle-on-join) to disable duty cycle for JOIN requests.
This flag can be used for testing only and is used to speed up JOIN request testing as
backoff times for JOIN request are really long (easily several minutes per attempt).
This flag works in conjunction with main duty cycle setting. Disabling duty-cycle-on-join
works only if duty-cycle-on is disabled (or region settings have duty cycle disabled).
LoRaMAC was not initialized properly if application called
connect(const lorawan_connect_t &connect);
This causes problems for example in case where application
first disconnects and then reconnects as counter values are not
initialized.
When node sends a CONFIRMED message and gateway sends ACK in RX1 window but the
message gets corrupted during the transmission (e.g. MIC fails), currently
our stack already checks for retransmission after RX1 and if retries attemps are
exhausted, TX_ERROR event is sent to application. This is wrong as MAC layer
will still attempt reception in RX2 window.
This commit fixes the behaviour so that TX_ERROR is not sent until RX2 window
has been closed.
It is quite possible that the user request for scheduling an uplink is deferred because of backoff or if it was a CONFIRMED message, a retry may take place on a different datarate and different channel.
We didn't have a hook for such deferred scheduling, telling the user whether the async rescheduling worked or not. This commit adds that capability and now we can tell the application if a scheduling failure took place after the original schedule request was accepted.
Hasnain Virk
Antti Kauppila
Kimmo Vaisanen
Kevin Bracey
Hugues Kamba
Teijo Kinnunen
Cruz Monrreal
itziar
Martin Kojtal