LoRa and LoRaWAN are related but distinct. Despite their burgeoning reputation as the go-to technologies for internet-of-things (IoT) based systems, and their increasing familiarity among low-power wide-area networking (LPWAN) operatives in any number of sectors, they are also often confused. Here, Enterprise IoT Insights seeks to untangle the two, and make clear their symbiosis.
Let us zoom out, momentarily. A telecoms system, of any sort, is characterised by certain components. The Open Systems Interconnection (OSI) model, for how applications communicate over a telecoms network, describes seven abstraction layers, reflected in a traditional telecoms ‘stack’, from device through to network and application.
At the device level, a physical (PHY) layer comprises the circuit transmission technologies and defines the specifications for data transfer. The PHY layer connects to a data link layer, the lowest in the networking architecture, which detects changes in the PHY layer and establishes a protocol to send data to adjacent nodes.
In simpler terms, the PHY layer defines how the electronic signal is modulated, and the data transfer layer actively selects the protocol to transmit it. From here, the communication is pushed easily through the other five layers, as defined in the OSI model – the network layer, transport layer, session layer, presentation layer and application layer.
With the root-level telecoms system pulled apart, we can draw out distinctions between LoRa and LoRaWAN. LoRa is the modulation format, owned by California-based Semtech. (As an aside, this marks out its business model from rivals like LPWAN operator Sigfox, as LoRaWAN networks are privately built and privately managed, using chips licensed from Semtech.)
LoRa exists in the PHY layer only, and enables the long-range communication link. Where most legacy wireless systems use frequency shifting keying (FSK) modulation as the PHY layer, LoRa is based on a modulation technique called chirp spread spectrum (CSS), which maintains the same low power characteristics as FSK but increases the communication range.
To pinpoint LoRaWAN, we need to go deeper. The data link layer in IEEE 802 local area networks is comprised of two sub-layers, including the media access control (MAC) sub-layer, designed for large-scale public networks with a single operator. LoRaWAN (or a LoRa based equivalent like Symphony Link) exists here, in the data link layer, and more precisely the MAC sub-layer.
It is an open-standard that defines the communication protocol for LPWAN technology based on a LoRa chip. It should be noted, the protocol and architecture, governed by LoRaWAN in the MAC sub-layer, have the most influence in determining the battery lifetime of a node, the network capacity, the quality of service, the security, and the variety of applications served by the network.
In sum, LoRa is the PHY layer, LoRaWAN is the data link layer, and the two together comprise the LPWA networking technology stack.
