SimtoLink Launches NB-IoT Narrowband IoT Solution to Empower Internet of Everything

NB-IoT (Narrowband Internet of Things) is a narrowband IoT radio technology defined by the 3GPP standards body and an important branch of IoT. NB-IoT focuses on the low-power wide-area (LPWA) IoT market and is an important part of the Internet of Everything.

Technical characteristics and standards evolution

NB-IoT is built on cellular networks and consumes only about 180 kHz of bandwidth. It can be deployed directly on a GSM, UMTS, or LTE network to lower deployment cost and allow a smooth upgrade. NB-IoT has wide coverage, many connections, low power, and low cost, and it suits IoT applications that send small amounts of data often.

Compared with traditional cellular networks, NB-IoT is heavily optimized for IoT. It simplifies the protocol stack, lowers bandwidth demand, strengthens coverage, and supports connections at scale, while keeping terminal power extremely low. These traits make NB-IoT a suitable connectivity technology for smart metering, smart parking, smart agriculture, and asset tracking.

Traditional 2G/3G/4G networks can support IoT connections, but power, cost, and coverage do not meet large-scale IoT deployment. NB-IoT is optimized in two directions, slimming down and strengthening: it lowers terminal complexity and cost, and it improves deep coverage and massive connectivity. In 2015, 3GPP started NB-IoT standardization. In June 2016, Release 13 was frozen and the standard was published. In 2017, operators worldwide began commercial deployment. In 2018, Release 14 enhanced positioning and multicast. In 2019, Release 15 introduced early data transmission and wake-up signals. It was later brought into the 5G standards and became an important technology for 5G mMTC.

The four core characteristics are: wide coverage, with coverage about 20 dB stronger than existing networks and coverage area expanded 100 times; massive connectivity, with 50,000 connections per cell, 50–100 times existing networks; low power, with battery life of 10 years or more; and low cost, with module cost as low as 5 US dollars. On key technologies, coverage gain can reach 164 dB, about 20 dB above traditional LTE, reaching basements and remote areas. Uplink rate is about 60 kbps and downlink rate is about 30 kbps. PSM and eDRX are supported, and an AA battery can last more than 10 years.

Deployment modes and power-saving techniques

NB-IoT supports three deployment modes. Standalone deployment uses a separate band, suits GSM spectrum refarming, and occupies 180 kHz. Guard-band deployment uses the LTE guard band and does not affect LTE service. In-band deployment allocates resource blocks inside the LTE bandwidth, shares LTE resources, and suits dense coverage. The physical layer uses single-tone transmission and repetition to strengthen coverage. The MAC layer simplifies the HARQ process. The RRC layer introduces power-saving mode and eDRX. Upper-layer protocols reduce signaling overhead. System bandwidth is 180 kHz, occupying one physical resource block. Uplink subcarrier spacing is 15 kHz and 3.75 kHz. Downlink spacing is uniformly 15 kHz.

PSM lets a device enter deep sleep and keep only a minimum of circuitry, so power can fall to the microamp level. The device stays registered on the network but turns the receiver off, and it can wake quickly without reattaching. The cycle can run from a few minutes to several days. eDRX extends the paging cycle from seconds to minutes. The device stays registered, and the network can deliver data in the paging window. Combined, the two can support standby of more than 10 years.

Applications and selection

Smart metering covers remote reading of water, electricity, gas, and heat meters. Smart city covers smart street lights, smart parking, environmental monitoring, and waste management. Smart agriculture covers soil monitoring, smart irrigation, livestock management, and greenhouse control. Asset tracking covers logistics tracking, equipment management, pet tracking, and shared equipment.

The network architecture includes terminal devices, the access network, the core network, and the IoT platform. A terminal integrates an NB-IoT module, a SIM or eSIM, an application processor, and sensors. The core network includes MME, S-GW, P-GW, and HSS. For selection, a battery-powered device should prefer PSM and eDRX. Weak-coverage sites such as basements and pipe wells should use a module that supports the maximum number of repetitions. NB-IoT module cost is lower than Cat.1, data charges are low, and it suits deployment at scale. Release 14 enhances positioning, multicast, and non-anchor carriers. Release 15 optimizes early data transmission, wake-up signals, and mobility, and converges with 5G mMTC.

Source: https://www.simtolink.com/support/communication/nb-iot-technology.html