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What is difference between Implicit header and Explicit header in LoRaWAN, LoRa

This page describes difference between Implicit header and Explicit header in LoRaWAN packet structure.

It is one of the LPWAN technologies used for long range, low power and offers less interference. LoRa packet consists of three elements viz. preamble, header (optional) and payload.

LoRa PHY structure

The above is the common LoRa PHY structure as defined in LoRaWAN specifications. In order to be compliant with LoRaWAN, end device should support following LoRa physical layer settings.
Preamble size: 8 symbols
Sync Word : 0x34 (Public)
Header : Explicit in uplink/downlink
CRC presence : True (Uplink value) and false (Downlink value)
Spreading factor (SF) and BW : As per region and defined by data rate
IQ Polarizaton : Not-inverted (in uplink) and Inverted (in downlink)

Explicit header

Explicit header in LoRaWAN packet

The figure depicts explicit header mode used in LoRa physical layer. Here PHY header (PHDR) and header CRC are included. Here PHDR contains payload length (in bytes), Coding rate (CR) and presence of optional CRC for payload. The integrity of payload is protected by CRC for uplink messages.

Implicit header

Implicit header in LoRaWAN packet

The figure depicts implicit header mode. It contains neither PHDR nor PHDR_CRC. LoRaWAN beacons use implicit header mode with fixed length for transmission.

LoRaWAN related links

The LoRaWAN Wireless tutorial covers following sub topics:
LoRaWAN Smart Parking   LoRaWAN sensor design   LoRaWAN smart healthcare system   LoRaWAN smart water metering   LoRaWAN architecture   LoRaWAN Interface Types   LoRaWAN roaming types   LoRa tutorial   LoRa Frequency Bands   LoRa protocol stack   LoRa MAC layer   LoRaWAN classes   LoRa features   LoRa Transceiver module  

IoT Wireless Technologies

WLAN    ➤THREAD    ➤EnOcean    ➤LoRa    ➤SIGFOX    ➤WHDI    ➤Zigbee   ➤6LoWPAN   ➤Zigbee RF4CE   ➤Z-Wave   ➤NFC   ➤RFID   ➤Lonworks   ➤CEBus   ➤UPB  

What is difference between

Difference between OSI and TCPIP layers  Difference between TCP UDP  FTP vs HTTP   FTP vs SMTP   FTP vs TFTP   ARP vs RARP   NAT vs PAT   RIP vs OSPF  SLIP vs PPP  IMAP4 vs POP3  IPV4 vs IPV6 

RF and Wireless Terminologies