LoRaWAN & NB-IoT

LoRaWAN and NB-IoT

The Internet of Things (IoT) is changing the way we interact with our devices, and LoRaWAN and narrowband IoT (NB-IoT) are two leading Low-Power Wide-Area Network (LPWAN) technologies. NB-IoT is optimized for spectrum efficiency and operates in cellular networks, while LoRaWAN operates in unlicensed radio spectrum and offers greater flexibility and longer battery life for devices.

LoRaWAN, or Long Range Wide Area Network, is a wireless communication protocol that has been specifically designed for long-range communication between devices and the Cloud. It uses the unlicensed radio spectrum bands, such as the Industrial, Scientific and Medical (ISM) band, which enables low-power wide-area network (LPWAN) communication between end nodes and gateways connected to a network and application servers in the Cloud. LoRaWAN was developed by the LoRa Alliance, a global association of more than 500 member companies that promote the development and adoption of LoRaWAN.

The LoRaWAN protocol is based on chirp spread spectrum modulation, which allows it to transmit data over long distances while consuming minimal power. This makes it ideal for use cases that require long battery life and low data rates, such as smart cities, smart agriculture, and industrial automation.

LoRaWAN also offers a high level of security through its use of AES-128 encryption, which ensures that data transmitted between devices and the Cloud remains secure and private.

Another advantage of LoRaWAN is that it is compatible with cellular infrastructure, which makes it easy to integrate with existing LTE mobile networks. This allows for seamless communication between devices and the Cloud, regardless of location.

To facilitate communication between devices and the Cloud, LoRaWAN uses gateways that act as intermediaries between end nodes and application servers. These gateways receive data from end nodes and forward it to application servers in the Cloud, and vice versa. This allows for bidirectional communication between devices and the Cloud, which is essential for many IoT use cases.

Narrowband Internet of Things (NB-IoT), is a low-power, wide-area network (LPWAN) technology that has been designed to enable a wide range of IoT devices to connect to the internet. It is supported by two telecommunications standards associations, the 3rd Generation Partnership Project (3GPP) and GSMA, which share a common goal of advancing the interests of cellular networks and devices.

The 3GPP is collaboration between a number of different telecommunications standards bodies, including ETSI, ARIB, and TTC, among others. It is responsible for developing the standards that are used in mobile communications networks around the world, including 2G, 3G, 4G, and now5G.NB-IoT was first introduced as a standard by the 3GPP in 2016, and since then it has been adopted by a number of different countries and regions around the world. However, it has mainly been rolled out in China, where it is being used to support a wide range of IoT applications, including smart cities, industrial automation, and environmental monitoring.

Comparison:1

The difference between LoRaWAN and NB-IoT is the spectrum in which they operate and their optimization goals.

LoRaWAN operates in the unlicensed Industrial, Scientific and Medical (ISM) spectrum, which means that network operators and device manufacturers do not have to pay any license fees to use it. This makes LoRaWAN a more cost-effective option for IoT applications, especially for devices that require long-range and ultra-low power communication. LoRaWAN is optimized for long-range communication, and its protocol is designed to consume minimal power, allowing devices to operate for years without needing a battery replacement.

On the other hand, NB-IoT operates in the licensed cellular spectrum, which is optimized for spectrum efficiency over everything else. Cellular operators pay high license fees to use these frequency bands, which limits the number of licensees that can afford to operate NB-IoT services. NB-IoT is designed to be used by cellular operators, and its optimization goals include low power consumption, high spectrum efficiency, and improved coverage in hard-to-reach areas.

Comparison:2

LoRaWAN a low-power wireless communication protocol designed for IoT devices. It highlights the wide availability and adoption of LoRaWAN technology, with approximately 170 network operators offering connectivity across 181 countries. It also notes the significant number of end nodes (240 million) and gateways (3.2 million) currently in service.

NB-IoT (Narrowband IoT), a cellular technology that also enables IoT connectivity. It claims that NB-IoT has been rolled out in 62 countries,

Comparison:3

LoRaWAN networks are highly flexible and can be installed in various deployment scenarios, including public, private, open communities or hybrid networks, indoors or outdoors. In contrast, NB-IoT utilizes LTE cellular infrastructure and can only be deployed in outdoor public networks where there are 4G/LTE cellular towers. This means that base stations cannot be easily located elsewhere even if sensors are out of range of the base station.

LoRaWAN provides strong signal propagation capabilities, enabling use cases in urban settings that require deep in-building or underground connectivity as well as enabling networks to cover up to 30 miles per gateway in rural, open environments. In contrast, NB-IoT has weaker signal propagation capabilities and requires a high density of base stations to provide coverage, especially in areas with obstacles such as buildings or trees.

The cost to expand LTE network for IoT use cases is generally higher than for LoRaWAN networks, which may limit the scalability of NB-IoT.

Comparison:4

LoRaWAN uses asynchronous communication, meaning data is only sent when necessary. This helps to conserve battery life in sensor devices in the field by up to 10 years. The standard has been designed with a focus on low energy consumption, resulting in cost savings on battery replacement and maintenance.

NB-IoT maintains a synchronous connection to the cellular network, even when there is no data to send. This continuous connection consumes considerable battery life, which can lead to high battery replacement costs. The use of high precision electronics, heavy device stacks, multi-band spectrum design, and end-to-end synchronized protocol all contribute to increasing energy consumption.

LoRaWAN has a lower transmit current, which makes it more power-efficient. At 10dBm, LoRaWAN consumes only 18mA, while at 20dBm it consumes 84mA. This is significantly lower than NB-IoT, which consumes approximately 100mA at 13dBm and 220mA at 23dBm.

The lower power consumption of LoRaWAN makes it more suitable for use cases where battery life is critical, such as remote sensors and devices that are difficult to access. The differences in modulation allow LoRaWAN to be supported by very low-cost batteries, including coin cells. On the other hand, the higher power consumption of NB-IoT makes it more suitable for use cases where higher data rates and longer range are required, such as smart city applications.

LoRaWAN is noted to provide lower sensor bill of material (BOM) costs and longer battery life compared to NB-IoT. The reason is that LoRaWAN operates at a receive current of approximately 5mA, which is 3-5 times lower power overall than NB-IoT, which operates at a receive current of approximately 40mA. This means that LoRaWAN is more power-efficient and can operate for longer periods on the same battery.

On the other hand, NB-IoT has a higher power consumption compared to LoRaWAN, as communication between the cellular network and device consumes over 110mA on average, lasting tens of seconds at a time. Additionally, protocol overhead has a significant impact on battery life for devices that require 3, 5 or 10+ years of operation. This means that NB-IoT may be more suitable for applications where higher data rates and/or longer range are required, but battery life is less of a concern.

Comparison:5

LoRaWAN features a data rate of 293 to 50kbps. This means that the protocol is capable of transmitting data at a maximum speed of 293 kbps and a minimum speed of 50 kbps. However, the LoRaWAN standard adapts the data rate dynamically depending on the distance between the sensor and the gateway. This optimization helps to reduce the power budget of the signal and avoid collisions.

On the other hand, NB-IoT is a cellular network technology that is designed specifically for IoT applications. It operates in the licensed spectrum and uses narrowband radio frequencies to provide connectivity for devices with low data rates and low power consumption. The statement mentions that NB-IoT runs at a peak data rate of ~20kbps in the lower power single tone usage. This means that the maximum data rate that NB-IoT can achieve is around 20 kbps when using the single-tone transmission mode. However, the actual data rate that a device can achieve may vary depending on the network conditions and the distance from the base station.

Comparison:6

The MCL (maximum coupling loss)signal of LoRaWAN varies depending on regional regulatory limits, which means that the maximum distance over which a LoRaWAN device can communicate with a gateway is dependent on the specific region's regulatory limits. The link budget of LoRaWAN falls between 155dB and 170dB best case.

On the other hand, NB- is a cellular-based LPWAN technology that operates in the licensed spectrum band. It uses a narrowband modulation scheme and supports low data rates, making it suitable for low-power and low-bandwidth applications. NB-IoT requires significant repetition for remote sensors at a low bit rate to be able to support remote sensors, which means that it needs to transmit the same message multiple times to ensure that the message is correctly received. This increases the power budget required for the device. The link budget of NB-IoT rests at 164dB best case.

Comparison:7

LoRaWAN and NB-IoT are both Low Power Wide Area Network (LPWAN) technologies used for Internet of Things (IoT) applications. However, they differ in terms of their capabilities for mobile asset tracking.

LoRaWAN can support mobile sensors and track them as assets move from one location to another, even without GPS. This is made possible through the use of Time of Arrival (ToA) and Time Difference of Arrival (TDoA) localization techniques. These techniques leverage the propagation time of the radio signal between the sensor and multiple gateways to triangulate the position of the sensor. LoRaWAN's ability to track mobile assets is therefore not limited to idle mode cell reselection and can be done with good enough accuracy for many applications.

On the other hand, NB-IoT is limited to idle mode cell reselection, which is not optimized for mobile asset tracking. This means that NB-IoT can only track mobile assets when they are in idle mode and not actively transmitting data. Moreover, idle mode cell reselection is not accurate enough for many tracking applications, as it relies on the signal strength of neighboring base stations to determine the location of the asset. This method is prone to errors due to variations in signal strength caused by factors such as terrain and obstacles.

Comparison:8

LoRaWAN supports LR-FHSS (Low-Rate Frequency Hopping Spread Spectrum) data rates. LoRaWAN is well-suited for direct device-to-satellite communications because it limits downlink communications to prevent interference with terrestrial devices, optimizes battery life by minimizing energy consumption, and provides high link budget (the difference between the received signal power and the minimum required power for successful communication) under harsh radio conditions.

NB-IoT: This is a cellular IoT technology that uses narrowband radio frequencies and supports frequent downlink communications. NB-IoT is less suited for direct device-to-satellite communications because it requires high-energy consumption due to message repetitions to overcome harsh radio conditions. This can limit the battery life of devices, making them less suitable for remote or inaccessible locations.

Anil Manohar, ITI Limited.