How can NB-IoT and LTE-M coexist and interoperate with other 3GPP and non-3GPP technologies?

1 NB-IoT and LTE-M overview

NB-IoT and LTE-M are both based on the LTE (Long-Term Evolution) network, but they have different characteristics and capabilities. NB-IoT stands for Narrowband IoT, and it is designed to provide low-cost, low-power, and long-range connectivity for devices that transmit small amounts of data infrequently. It uses a narrow bandwidth of 200 kHz and operates in licensed spectrum. LTE-M stands for LTE for Machine-Type Communications, and it is designed to provide higher data rates, lower latency, and better mobility for devices that require more frequent and reliable communication. It uses a wider bandwidth of 1.4 MHz and also operates in licensed spectrum.

2 NB-IoT and LTE-M benefits

NB-IoT and LTE-M offer several advantages for IoT applications, such as security with the same encryption and authentication mechanisms as LTE, scalability with the capability to support many devices per cell, coverage through advanced modulation and coding techniques to enhance the signal strength and reach, battery life through power-saving modes and reduced signaling overhead, and compatibility by leveraging the existing LTE infrastructure and spectrum. These features make NB-IoT and LTE-M attractive options for IoT applications.

3 NB-IoT and LTE-M challenges

NB-IoT and LTE-M have some challenges, such as interference from other technologies that share the same spectrum or operate in adjacent bands, incompatibility with different network operators or regions using different frequency bands, higher device or subscription costs than non-3GPP technologies, and not meeting the requirements of some IoT applications that demand higher data rates, lower latency, or better mobility.

4 NB-IoT and LTE-M coexistence

NB-IoT and LTE-M can coexist in the same network, as they use different physical layer resources and can be deployed in different ways. There are three main deployment options for NB-IoT and LTE-M: in-band, guard-band, and standalone. In-band utilizes the same frequency band as LTE, but occupies different resource blocks within the LTE carrier. Guard-band uses the unused frequency band between two LTE carriers, avoiding interference with LTE. Standalone requires a new spectrum allocation and uses a dedicated frequency band that is separate from LTE. The choice of deployment option depends on the availability of spectrum, the network capacity, the interference level, and the operator's strategy.

5 NB-IoT and LTE-M interoperability

NB-IoT and LTE-M can be used in conjunction with other 3GPP and non-3GPP technologies, depending on the needs and preferences of the IoT application. For instance, they can interwork with 2G, 3G, and 4G networks, as well as 5G networks in the future, using the same SIM card and roaming agreements. Additionally, they can integrate with Wi-Fi or Bluetooth through a gateway device that connects them to the local area network or the internet. Furthermore, NB-IoT and LTE-M can coexist with LoRa or Sigfox by utilizing a dual-mode device that shifts between them based on the availability, cost, or performance of each technology. Ultimately, the decision of interoperability option is based on the availability of technologies, the network coverage, the data rate, the latency, and the battery life of the IoT application.

6 Here’s what else to consider

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