LoRa is the physical layer (PHY) technology, specifically a proprietary spread spectrum modulation technique based on Chirp Spread Spectrum (CSS). It defines how data is encoded onto radio waves for long-range, low-power transmission. LoRaWAN is a Media Access Control (MAC) layer protocol that operates on top of the LoRa physical layer. LoRaWAN defines the communication protocol and system architecture, managing aspects like device addressing, data security, network communication rules, and different device classes. In essence, LoRa provides the communication link, while LoRaWAN provides the network framework to manage it.

B: This is incorrect. LoRaWAN is the protocol that facilitates connecting end-devices to the internet via a network server; LoRa is the local radio link technology.

C: This is incorrect. Both LoRa and LoRaWAN are based on Radio Frequency (RF) communication, not light-based methods.

D: This is incorrect. The roles are reversed. LoRa is the Physical Layer (Layer 1), while LoRaWAN is a higher-level protocol, primarily at the MAC (Layer 2) and Network (Layer 3) layers.

1. LoRa Alliance, "What is LoRaWAN® specification": "The LoRaWAN protocol is the MAC layer that leverages the LoRa® physical layer. The LoRa® physical layer is the radio modulation that creates the long-range communication link." This document clearly separates LoRa as the physical layer modulation and LoRaWAN as the MAC layer protocol. (Source: LoRa Alliance official documentation).

2. Semtech Corporation, "What is LoRa?": "LoRa is the physical layer or the wireless modulation utilized to create the long range communication link. Many legacy wireless systems use frequency shifting keying (FSK) modulation as a physical layer because it is a very efficient modulation for achieving low power. LoRa is based on chirp spread spectrum modulation... LoRaWAN is the communication protocol and system architecture for the network..." (Source: Official vendor documentation from Semtech, the creator of LoRa technology).

3. Haxhibeqiri, J., De Poorter, E., Moerman, I., & Hoebeke, J. (2018). "A Survey of LoRaWAN for IoT: From Technology to Application." Sensors, 18(11), 3995. Section 2.1, "LoRa and LoRaWAN Technology": "LoRa is a proprietary modulation format owned by Semtech... It is a physical layer (PHY) technology... LoRaWAN is a MAC protocol for high capacity, long range, low power, star topology networks, which is standardized by the LoRa Alliance." (DOI: https://doi.org/10.3390/s18113995).