The rapid development of the Internet of Things (IoT) has placed higher demands on wireless communication technologies, and LPWAN (low-power wide-area network), which is designed for IoT applications with low bandwidth, low power consumption, long distance, and large number of connections, has also emerged rapidly.
IoT applications require consideration of numerous factors, such as node cost, network cost, battery life, data transmission rate (throughput), latency, mobility, network coverage, and deployment type. It's fair to say that no single technology can meet all the needs of IoT. NB-IoT and LoRa, with their distinct technical and commercial characteristics, are two of the most promising low-power wide-area network (LPWAN) communication technologies. Both LPWAN technologies offer wide coverage, high connectivity, low speeds, low cost, and low power consumption, making them suitable for low-power IoT applications, and both are actively expanding their ecosystems.
Internet of Things (IoT) communication technology
There are many wireless communication technologies for the Internet of Things (IoT), mainly divided into two categories: one is short-range communication technologies such as Zigbee, WiFi, Bluetooth, and Z-wave; the other is LPWAN, or wide-area network communication technology. LPWAN can be further divided into two categories: one is technologies such as LoRa and SigFox that operate in unlicensed spectrum; the other is 2G/3G/4G cellular communication technologies supported by 3GPP that operate in licensed spectrum, such as EC-GSM, LTE Cat-m, and NB-IoT.
LoRa and NB-IoT are both low-power wide-area IoT technologies and are currently the two mainstream technology schools in China.
Brief introduction to NB-IoT and LoRa
LoRa (LongRange) is an ultra-long-range wireless transmission solution based on spread spectrum technology, adopted and promoted by Semtech Corporation in the United States. This solution changes the previous trade-off between transmission distance and power consumption, providing users with a simple system that can achieve long-range, low-power, and high-capacity operation, thereby expanding sensor networks. A LoRa network mainly consists of four parts: terminals (which can have built-in LoRa modules), gateways (or base stations), servers, and the cloud. Application data can be transmitted bidirectionally.
NB-IoT (Narrowband Internet of Things) is a technical standard defined by the 3GPP standardization organization. It is a narrowband radio frequency technology designed specifically for the Internet of Things and can be widely used globally. It uses licensed frequency bands and can be deployed in three ways: in-band, guard band, or independent carrier, and can coexist with existing networks.
NB-IoT and LoRa frequency bands
NB-IoT uses licensed frequency bands and has three deployment methods: standalone deployment, guard band deployment, and in-band deployment. The mainstream frequency bands globally are 800MHz and 900MHz. China Telecom will deploy NB-IoT on the 800MHz band, while China Unicom will choose 900MHz, and China Mobile may refarm its existing 900MHz band.
LoRa uses the unlicensed ISM band, but the usage of ISM bands varies from country to country and region to region. In the Chinese market, the China LoRa Application Alliance (CLAA), led by ZTE, recommends using the 470-518MHz band. This 470-510MHz band is the band used for radio metering instruments. Because LoRa operates in an unlicensed band, network construction can be carried out without application, resulting in a simple network architecture and low operating costs. The LoRa Alliance is actively promoting the standardized LoRaWAN protocol globally, enabling devices compliant with the LoRaWAN specification to interconnect.
Communication distance of NB-IoT and LoRa
NB-IoT communication distance
The signal coverage of a mobile network depends on base station density and link budget. NB-IoT has a link budget of 164dB, GPRS has 144dB (TR45.820), and LTE has 142.7dB (TR36.888). Compared to GPRS and LTE, NB-IoT offers a 20dB improvement in link budget, increasing signal coverage in open environments by up to seven times. This 20dB difference is equivalent to the signal loss when penetrating building exteriors, meaning NB-IoT offers relatively better signal coverage indoors. Generally, the communication range of NB-IoT is 15km.
LoRa communication distance
LoRa offers a link budget of up to 168dB and a power output of +20dBm thanks to its proprietary technology. Generally, the wireless range is 1-2 kilometers in urban areas and up to 20km in suburban areas.
Cost Comparison of NB-IoT and LoRa
No matter how powerful LPWAN protocols are, low cost must be considered; otherwise, they cannot be viable IoT solutions. LoRa has an advantage in this regard, with the total cost of a LoRaWAN module around $8-10, about half the price of cellular LTE modules such as NB-IoT. NB-IoT networks are more complex, and intellectual property-related costs (regarding licensed frequency bands) are higher, increasing the overall cost of NB-IoT. Upgrading NB-IoT to advanced 4G/LTE base stations is more expensive than deploying LoRa via industrial gateways or tower-top gateways. As the market matures, the cost of LoRa technology is expected to decrease further.
Comparison of applicable scenarios
Examples of NB-IoT application scenarios
(1) Shared bicycles: Widely distributed with low unit density, suitable for leveraging operator networks;
(2) Smart meter reading: For homeowners who do not require high data collection frequency, do not have high requirements for network availability, and do not want to consider building their own base stations.
(3) Water accumulation/pipeline monitoring: Widely distributed with low unit density;
(4) General-purpose wearable series: The terminals are distributed throughout the urban area and are suitable for use with operator networks;
(5) Smart Parking: Ruijie Networks developed a geomagnetic vehicle detector for "Xiaoheqingting". It uses geomagnetism to sense changes in the magnetic field and thus judges whether a vehicle is entering or leaving the parking space. The uplink and downlink wireless links adopt the NB-IoT standard and are connected to OneNET to support the parking platform application of the 5G Joint Innovation Lab.
Examples of LoRa application scenarios
(1) Smart meter reading: Homeowners have high requirements for data collection frequency and data analysis, as well as high requirements for network availability;
(2) Road parking detector: The sampling frequency is relatively high, but there are certain requirements for the lifespan of the terminal;
(3) Suburban areas, such as mining, quarrying, and suburban heavy industry;
(4) Regionally concentrated type: such as users in universities, primary and secondary schools, and industrial parks who want to build private networks to manage their facilities and applications.
in conclusion
Both NB-IoT and LoRa are currently in their early stages of development, requiring investment and collaborative efforts from all parties. As large-scale deployment becomes a reality, the cost of NB-IoT and LoRa modules will naturally decrease further. In terms of technical solutions, NB-IoT and LoRa will undoubtedly coexist in the short term, each with its own advantages and disadvantages; it's difficult to say which will prevail. However, if influenced by factors beyond technical solutions, such as innovative profit models, close integration with application industries, and leveraging industry influence, anything is possible. In this new wave of IoT development, getting projects implemented first is crucial for gaining a competitive edge. NB-IoT and LoRa require not only product innovation but also innovation in project applications.
