Figure: Overview of LoRaWAN
LoRaWAN is a networking protocol based on LoRa technology. As a protocol aimed at wide area networks, its features include gateway collaboration and large access volume. It was recognized as an international standard by the International Telecommunication Union (ITU) in November 2021. LoRa has become one of the mainstream technologies in the LPWAN field, and LoRaWAN® has been approved by the International Telecommunication Union as an international standard. As of now, more than 2.7 million LoRa-based gateways have been deployed globally, with over 225 million LoRa or LoRaWAN-based end devices, and LoRa or LoRaWAN deployment has covered 171 countries and regions.
LoRa and LoRaWAN together define a low-power wide area (LPWA) network protocol aimed at wirelessly connecting battery-powered devices to regional, national, or global networks on the Internet and addressing key IoT requirements such as bi-directional communication, end-to-end security, mobility, and localization services. LoRaWAN employs long-range, low-power, low-rate, and low-cost technologies, providing a low-power wide area network (LPWAN) connectivity solution for IoT devices.
With the help of CSS and ADR, LoRaWAN coverage range allows devices to communicate with gateways up to 15 kilometers away in open areas, and up to 5 kilometers away in urban areas, meaning a single gateway can cover all devices within a 700-square-kilometer area. The coverage range also extends indoors, reaching service conduits below basements or streets.
- Advantages: Long transmission distance, low power consumption, and higher security. In addition, the cost of LoRaWAN equipment is relatively low, which can meet the needs of large-scale Internet of Things applications.
- Disadvantages: The transmission rate is low and does not support real-time communication, so it is not suitable for application scenarios that require real-time response. LoRaWAN uses the same frequency bands as other devices and networks, so it may experience interference in dense environments.
Figure: Application scenarios of Zigbee
ZigBee is a wireless local area network communication technology characterized by low speed, low power consumption, short range, and self-organizing network capabilities. It was formally introduced in 2003 to address the shortcomings of the Bluetooth communication protocol, which suffers from high complexity, high power consumption, limited range, and small network capacity. The name " ZigBee " was inspired by the way bees communicate with each other through a "dance" of wing vibrations and buzzing in order to convey information about the location of pollen. This type of communication forms a network among the group of bees.
ZigBee has been standardized as IEEE 802.15.4 and operates in three frequency bands: 868MHz-868.6MHz, 902MHz-928MHz, and 2.4GHz-2.4835GHz. The last frequency band is globally used, has 16 channels, and is a free and unlicensed radio frequency band. The transmission rates for the three frequency bands are 20kbps, 40kbps, and 250kbps, respectively.
- Advantages: ZigBee technology boasts low power consumption, vast network capacity, and flexible working frequency bands.
- Disadvantages: The technology suffers from slow data transmission rates, a limited effective range, poor resistance to interference, the lack of an open source ZigBee protocol, and comparatively complicated interoperability with the IP protocol.
Figure: Application Scenarios of WiFi
WiFi, short for Wireless-Fidelity, is a series of wireless network protocols based on the IEEE 802.11 standard. It is commonly used for local and internet access of devices, allowing digital devices in proximity to exchange data through radio waves. These are the most widely used computer networks in the world, used for home and small office networks worldwide, connecting desktop and laptop computers, tablets, smartphones, smart TVs, printers, and smart speakers together to a wireless router to connect them to the internet. They also provide internet connectivity for visitors' phones at wireless access points in public places such as cafes, hotels, libraries, and airports.
The radio frequencies of Wi-Fi have a relatively high absorption rate, and the indoor range of access points is approximately 20 meters (66 feet), while some access points claim outdoor ranges of up to 150 meters (490 feet). The coverage area of a hotspot can be as small as a single room with walls that block radio waves, or as large as a square kilometer using many overlapping access points and allowing them to roam between them.
- Advantages: Wi-Fi offers the advantage of deploying a local area network without the need for electrical wires, reducing deployment and expansion costs. In addition, according to the Wi-Fi Alliance, "Wi-Fi certification" is backward compatible, specifying a globally unified standard, allowing any Wi-Fi standard device to operate correctly anywhere in the world.
- Disadvantages: Wi-Fi has limited communication distance, poor stability, higher power consumption, weaker networking capability, and lower security compared to other communication technologies.
Figure: What is NB-IOT
NB-IoT, which stands for Narrow-band Internet of Things, is a communication technology designed specifically for IoT devices. It is a low-power, wide-area network (LPWAN) based on cellular networks, utilizing only approximately 180KHz of bandwidth. This technology can be deployed directly on GSM (2G), UMTS (3G), or LTE (4G) networks, thereby reducing deployment costs and enabling smooth upgrades. NB-IoT is a novel technology in the IoT domain, providing efficient, secure, and stable communication services for large-scale IoT device connections. It facilitates cellular data connections for low-power devices in a wide area network and is also known as low-power wide-area network (LPWAN).
- Advantages: NB-IoT boasts a wide coverage area, extended battery life, and a low cost structure while simultaneously supporting high device density connections. With end-to-end encryption techniques, NB-IoT provides secure data transmission for connected devices.
- Disadvantages: However, NB-IoT suffers from high latency, a limited number of channels, and a dependence on infrastructure, which may hinder its implementation in remote or less developed areas.
The following is the comparison and advantages and disadvantages of the four technologies for your reference:
Figure:Comparison of LoRaWAN, Zigbee, WiFi and NB-IoT four technologies
To sum up, LoRaWAN, Zigbee, WiFi and NB-IoT are all common wireless communication technologies, each of which has different advantages and disadvantages and applicable scenarios. LoRaWAN is suitable for long-distance low-speed data transmission and can be used in IoT applications, urban intelligence, and agriculture. Zigbee is suitable for data transmission at medium distances and rates, and is suitable for fields such as home automation and industrial automation. WiFi is suitable for high-speed data transmission and broadband access, suitable for home, office and public places and other fields. NB-IoT is suitable for IoT applications with low power consumption and wide area coverage.
Therefore, when choosing a communication technology, you need to make a choice based on specific application scenarios and needs.