IEEE Std 802.15.4w-2020 pdf free download – IEEE Standard for Low-Rate Wireless Networks Amendment 2: Low Power Wide Area Network (LPWAN) Extension to the Low-Energy Critical Infrastructure Monitoring (LECIM) Physical Layer (PHY).
23. LECIM FSK PHY specification
23.1 General
Change 23.1 and insert Figure 23-a as follows:
LECIM FSK transmission supports two different modes: split and non-split. When phyLecimFskSplit is set to true, split mode shall be enabled, when it is set to false, non-split mode shall be enabled. The mode is preconfigured and switching between the modes during operation is not supported.
In non-split mode, a PSDU is transmitted in a single packet. In split mode, the PSDU and PHR are jointly FEC encoded and split to form multiple radio-burst payloads that are transmitted on different channels at different times.
The difference between split and non-split mode is illustrated in Figure 23-a.
A single radio-burst is not decodable on its own; instead, multiple radio-bursts have to be combined to reconstruct the PSDU. The minimum number of collected radio-bursts for successful reconstruction is dependent on the applied FEC.
A device may support non-split or split mode or both.
The intention of the LECIM FSK Operating Mode IE is to allow a higher layer to perform remote configuration of a LECIM FSK device in an interoperable manner.
23.2 PPDU format for LECIM FSK PHY
23.2.2 SHR field format
23.2.2.2 Preamble field format
Change 23.2.2.2 as follows:
The attribute phyLecimFskPreambleLength, as described in 11.3, controls the length of the preamble. The Preamble field shall contain phyLecimFskPreambleLength, as defined in 11.3, multiples of the 8-bit sequence “01010101”. The preamble field shall be omitted when phyLecimFskPreambleLength equals 0.
In non-split mode, for the purposes of calculating the Ack frame timing required in 6.7.5, the Preamble field length of 4 octets shall be used.
For split mode, the Ack frame timing shall be calculated based on the first radio-burst and using the reamble field length of 0 octets.
23.2.3 PHR field format
Insert new text at the end of 23.2.3 as follows:
For non-split mode, the full 11-bit range PSDU size given by the Frame Length field shall be supported.
The maximum PSDU size for split mode shall be 184 octets.
NOTE—The actual PSDU size may not be known to the receiver before reception of the last radio burst. A lower maximum PSDU size may be chosen based on implementation requirements.
Insert new subclause 23.2.5 after 23.2.4 as follows:
23.2.5 Radio-burst format
The structure of radio-burst is depicted in Figure 23-4a.IEEE Std 802.15.4w pdf download.