Apart from indoor smart building applications, for outdoor IoT applications in smart buildings/cities, a different set of requirements is needed. These applications require transmission technologies with longer range, lower power consumption, and often operate on battery power with the need for multi-year battery life. In such cases, Low-Power Wide Area (LPWA) network technologies become the preferred choice for these popular applications. This article will introduce the applications and development of LPWA networks and the related solutions offered by Murata.
LPWA technologies that focus on power efficiency and long-range data
LPWA networks, suitable for larger-scale smart building and smart city applications, are wireless communication technologies specifically designed for interconnecting devices with a focus on power efficiency and long-range data transmission. LPWA is well-suited for applications such as IoT (Internet of Things), machine-to-machine (M2M) communications, and many other applications that require operation at lower cost and power consumption. LPWA technologies are rapidly gaining popularity.
LPWA networks can utilize different network technologies for data transmission, including cellular networks and LoRa network technology. For example, LTE-M technology, which uses cellular networks, is a type of LTE (Long-Term Evolution) technology known as LTE Cat-M1 or LTE-M, specifically designed for IoT devices to connect directly to 4G networks through mobile network operators (MNOs) like AT&T or Verizon, without the need for gateways, and typically operated with batteries.
LTE-M includes the eMTC (enhanced Machine Type Communication) standard, which is a LPWA network radio technology standard developed by 3GPP to enable a wide range of cellular devices and services, particularly for M2M and IoT applications. LTE-M offers higher data rates, supports mobility and voice over the network, but requires larger bandwidth compared to Narrowband IoT (NB-IoT) and cannot fit into guard bands like NB-IoT.
NB-IoT, on the other hand, is a standardized LPWA technology aimed at supporting various types of IoT devices and services. NB-IoT significantly improves power consumption, system capacity, and spectrum efficiency of user devices, especially in deep coverage areas. NB-IoT uses a subset of LTE standards but limits the bandwidth to a single narrowband of 200 kHz.
LoRa technology, designed for low-power, low bit rate, and IoT applications
LoRa (short for "Long Range") is a proprietary wireless communication technology based on spread spectrum modulation derived from Chirp Spread Spectrum (CSS) technology. It was initially developed by Cycleo, a French company, and later acquired by Semtech. LoRaWAN™ (Wide Area Network) defines the communication protocol and system architecture and is an official standard of the International Telecommunication Union (ITU). LoRa and LoRaWAN™ together define an LPWA network protocol designed to wirelessly connect battery-powered devices to regional, national, or global networks on the Internet, addressing key IoT requirements such as bidirectional communication, end-to-end security, mobility, and localization services. The data rates for LoRaWAN™ range from 0.3 kbit/s to 50 kbit/s per channel, meeting the needs of low-power, low bit rate, and IoT applications.
LoRa operates in unlicensed sub-GHz radio frequency bands, such as 433 MHz, 868 MHz (Europe), 915 MHz (Australia and North America), and 923 MHz (Asia). It enables long-range communication with low power consumption, allowing for transmission distances of over 10 kilometers in rural areas. LoRa and LoRaWAN™ enable long-range connectivity for IoT devices in various industries.
LoRa defines the lower layers of the communication stack and does not specify the upper-layer network protocol. There are multiple protocols that can define the upper-layer network protocol for LoRa, and LoRaWAN™ is one of them. LoRaWAN™ is a cloud-based Media Access Control (MAC) layer protocol, but it functions similar to a network layer, managing communication between LPWA network gateways and end-devices, resembling a routing protocol. It is maintained by the LoRa Alliance.
The world's smallest LTE Cat.M1/NB-IoT module
LTE Cat.M1/NB-IoT is a licensed standard that requires a license to use radio frequencies, making it particularly suitable for IoT applications where cost and power consumption need to be minimized even at slower speeds. LTE Cat.M1/NB-IoT is especially suited for mobile communications, as it operates in licensed frequency bands, resulting in reduced radio interference and faster speeds. It can be used in various applications, including IoT and wearable devices.
Murata has designed the world's smallest LTE Cat.M1/NB-IoT module, which is globally certified and supports GPS/GNSS, OpenMCU, and iSIM (optional). LTE Cat.M1 (LTE-M) offers high reliability, low latency, and low power consumption, making it suitable for battery-replacement IoT devices. NB-IoT is expected to be used in low-power IoT solutions, particularly in environments where battery replacement is difficult or commercial power sources are unavailable, such as smart meters, remote healthcare monitoring, or anomaly detection during disasters.
The Type 1SE (LBAD0ZZ1SE) module launched by Murata is a Cat.M1/NB-IoT module that complies with Japanese certification standards and supports Truphone's eSIM technology. The Type 1SE module integrates an MCU, eSIM, and LTE-M/NB1 modem and comes with certified terminal devices with antenna connections, making it easy to integrate into a variety of applications.
The Type 1SE module supports LTE Cat.M1/NB-IoT Release 13, with support for low-frequency bands 5, 8, 12, 13, 14 (Cat.M1 only), 17, 18, 19, 20, 26, 28, as well as mid-frequency bands 1, 2, 3, 4, 25. It features the Altair ALT1250 and ST STM32L462 chipsets, with a compact size of only 15.4 x 18.0 x 2.5mm and an LGA metal package. The module supports UART host interface and peripheral interfaces such as ADC, GPIO, I2C, JTAG, PWM, and SPI. It has a U.FL connector for antenna configuration, operates at a voltage of 3.3V, power supply voltage of 3.3-5.0V, and operates in a temperature range of -40°C to 85°C. The power levels have been optimized for three classes of LTE output power. The module is compliant with RoHS regulations and provides X-CUBE-CELLULAR software features. It consumes extremely low current in sleep mode, resulting in a long battery life of up to 10 years, with a hibernation current of only 3µA and eDRX current less than 50µA in 8 hyperframes mode. It supports the configuration of PSM (Power Saving Mode) current dormant windows and has a maximum transmit power of +23dBm. The module is certified by FCC/IC/RED/TELEC and has obtained certifications from GCF/PTCRB, as well as global operator certifications from Truphone.
Compared to unlicensed LPWA communication systems, the networks of major mobile network operators (licensed frequency bands) offer wider and more stable communication coverage. The bottom area of the Type 1SE module is approximately 50% smaller than typical LPWA modules, enabling high-density circuit design.
The Type 1SE module operates in the same frequency bands as LTE with a bandwidth of 1.4 kHz and supports licensed frequency bands of operators. The maximum transmission rate for both upstream and downstream is 1 Mbps, with a communication range exceeding 10 km.
A small-sized, long-range, long battery life, and secure LoRa module
On the other hand, non-cellular LPWA is a communication technology that operates in the sub-GHz frequency band. This technology includes LoRaWAN™, which is a license-free and compatible with remote wireless protocols. LoRaWAN™ is a standard developed by the LoRa Alliance™. Murata has deployed modules that support LoRaWAN™ and has developed the world's smallest LoRa module series, measuring only 10.0 mm × 8.0 mm × 1.6 mm. These modules are suitable for various high-volume applications that require small size, long-range, extended battery life, security, and competitive pricing. The series is based on the second-generation Semtech SX1262 RFIC and includes the Type 1SJ (LBAA0QB1SJ) LoRa module, which features an open STM32L0 microcontroller (MCU) from STMicroelectronics, an RF switch, 192 kB flash memory, and 20 kB RAM. The extensive memory supply ensures sufficient resources for the application layers. The compact module also includes a temperature-controlled crystal oscillator (TXCO) and multiple communication interfaces, including UART/I2C/SPI/ADC/USB and various GPIOs.
Designed for global deployments, the module supports ISM frequency bands from 868 MHz to 916 MHz, including those used in Europe, the United States, India, and the Asia-Pacific region. The device has a single part number for global use, simplifying the customer's supply chain.
The Type 1SJ module operates on a single power supply rail (up to 3.9V DC) and incorporates various low-power modes. The real-time clock (RTC) can operate with a typical current consumption of only 1.3 µA, enabling devices based on Murata modules to run on a single battery for years. The module is packaged in resin mold, providing physical robustness and enabling it to operate within a temperature range of -40°C to +85°C.
The Type 1SJ module is one of the smallest LoRaWAN™ modules in the industry. Compared to previous products, it offers lower power consumption and higher output. It has obtained radio law certifications in major regions and provides open MCU design support. The Type 1SJ module supports the LoRaWAN™ channel frequency band of 860-930 MHz, utilizes Semtech SX1262 and STM STM32L chipset, supports FSK and LoRa™ modulation, and comes with an external antenna. The interface voltage (Vdc for VIO) is 3.3 Vdc, and the minimum power supply voltage for VDD_MCU, VDD_RF, and VDD_TCXO is 2.2V, while the maximum power supply voltage is 3.6V. The transmit mode current is 118 mA at 22 dBm setting, and the transmit power can reach up to +21.5 dBm. The receive mode current is 15.5 mA at 125 kHz BW, and the receiver sensitivity is -135.5 dBm at 1% PER, 125 kHz BW, SF=12. The module is RoHS compliant, has passed FCC/IC "reference" certification, and is available in three variant models: LBAA0QB1SJ-295, LBAA0QB1SJ-296, and LBAA0QB1SJ-686.
The Type 1SJ LoRa module will assist designers in developing solutions that meet the most demanding requirements, especially in areas such as asset tracking, utilities, agriculture, smart cities, smart buildings, industrial applications, and other IoT applications.
Conclusion
In outdoor applications for smart buildings/cities, LPWA technology is necessary to achieve long-range, low-power, battery-operated connectivity and data transmission between IoT devices. This technology is used for remote or outdoor monitoring of various intelligent structures such as dams, bridges, oil and gas platforms, smart grids, etc. In such scenarios, cellular networks like LTE Cat.M1/NB-IoT or LoRa/LoRaWAN™ network technology are the most suitable solutions. Murata has developed a high-integration module product series that supports these LPWA