Use a cellular and GPS SiP to implement asset tracking for agriculture and smart cities
damage can provide significant benefit to suppliers and purchasers to correct shipment problems. Besides following packages through the supply chain, most enterprises need improved methods for tracking their own assets and locating misplaced items. Yet, half of all businesses still manually log assets, and of those, many rely on employees to search through warehouses, plants, and physical locations to find missing assets. Comparing connectivity technologies for asset tracking Although a number of solutions have emerged to help automate asset tracking, the underlying technologies have limited coverage area, are expensive per unit cost, or have high power requirements. The latter is critical as asset tracking and remote IoT devices are battery- powered devices. Conventional tracking methods based on passive radio frequency identification (RFID) cannot provide live data in transit and require packages to pass through some physical checkpoint to detect the RFID tag attached to a package. Battery-powered active RFID tags are able to provide real-time location data but require additional infrastructure and remain limited in coverage.
Alternatives based on low-power ultra-wideband (UWB) technologies can achieve significant range, but network coverage remains limited. In fact, few alternatives can provide the kind of global coverage already available with low-power wide-area network (LPWAN) cellular solutions based on LPWAN technology standards defined by 3rd Generation Partnership Project (3GPP) – the international consortium that defines mobile communications standards. Achieving global reach with cellular connectivity Among 3GPP standards, those based on LTE-M and NB-IoT technologies are designed specifically to provide a relatively lightweight cellular protocol well matched to IoT requirements for data rate, bandwidth, and power consumption. Defined in 3GPP Release 13, LTE Cat M1 is an LTE-M standard that supports 1 megabit per second (Mbit/s) for both downlink and uplink transfers with 10 to 15 millisecond (ms) latency and 1.4 megahertz (MHz) bandwidth. Also defined in 3GPP Release 13, Cat-NB1 is an NB-IoT standard that offers 26 kilobits per second (Kbits/s) downlink and 66 Kbits/s uplink with 1.6 to 10 s latency and 180 kilohertz (kHz) bandwidth. Defined in 3GPP Release 14, another NB-IoT standard, Cat-NB2 offers higher date rates at 127
Kbits/s downlink and 159 Kbits/s uplink. Although the specific characteristics of these two broad classes of LPWAN technology lie well beyond the scope of this brief article, both can serve effectively for typical asset tracking applications. Combined with sensors and global positioning satellite (GPS) capabilities in compact packages, asset tracking solutions based on LTE-M or NB-IoT based cellular LPWANs can support the kind of capabilities required for asset management and end-to-end logistics. Given LPWAN’s potential for achieving greater efficiency and cost savings, cellular LPWAN continues to play a greater role in logistics. With the availability of the nRF9160 SiP from Nordic Semiconductor, developers can more quickly and easily serve the growing demand for LPWAN- based devices needed for more effective asset tracking or other IoT applications.
array (LGA) package. Along with an Arm Cortex-M33-based microcontroller dedicated to application processing, nRF91 SoC variants integrate an LTE-M modem in the NRF9160-SIAA SiP, NB-IoT modem in the NRF9160-SIBA SiP, and both LTE-M and NB-IoT as well as GPS in the NRF9160-SICA SiP. Furthermore, the nRF9160 SiP is pre-certified to meet global, regional and carrier cellular requirements, allowing developers to quickly implement cellular connectivity solutions without the delays typically associated with compliance testing. All SiP versions combine the microcontroller-based application processor and modem with an extensive set of peripherals, including a 12-bit analog-to-digital converter (ADC) often needed in sensor designs. The SiP further packages the SoC with an RF front- end, power management integrated circuit (PMIC), and additional components to create a drop-in solution for LPWAN connectivity (Figure 2). Serving as the host processor, the SoC’s microcontroller integrates a number of security capabilities designed to meet the growing demand for security in connected devices, including IoT devices and asset tracking systems. Building on the Arm TrustZone architecture, the microcontroller embeds an Arm Cryptocell security block, which combines a public key cryptography accelerator
Figure 1: Advanced direction-finding capabilities in Bluetooth support precision location of a tag in three-dimensional space. Image source: Nordic Semiconductor
low energy (BLE) and Wi-Fi offer progressively greater range within a coverage area equipped with fixed locators for each technology. Building on a rich ecosystem of devices and software, BLE and Wi-Fi are already applied in location-based applications such as COVID-19 contact tracing and conventional real-time location services (RTLS), respectively. With the availability of direction-finding features in Bluetooth 5.1, the location of a tag can be accurately calculated based on angle-of-arrival (AoA) and angle-of-departure (AoD) data (Figure 1). While BLE applications remain limited to short-range applications, Wi-Fi’s greater range can make it effective for use in asset tracking applications within a warehouse or enterprise campus. Yet, Wi-Fi RTLS tags are typically expensive devices
with power requirements that make batteries impractical, thereby limiting its use to tracking larger, expensive assets. At the same time, large-scale deployments using either of these technologies can suffer from increasing noise in their reception bandwidth, leading to lost or corrupted packets and degradation of location detection capabilities. Despite their potential use for tracking assets locally, neither RFID, BLE, nor Wi-Fi can provide the range of coverage needed to easily track an asset once it leaves the warehouse or enterprise campus. The ability to track a package or piece of equipment regionally or even globally depends on the availability of a wireless technology able to achieve both extended reach and low power operation.
How a SiP device can deliver a drop-in asset tracking solution
Nordic Semiconductor’s low-power nRF9160 SiP device combines a Nordic Semiconductor nRF91 system-on-chip (SoC) device with support circuitry to provide a complete LPWAN connectivity solution in a single 10 x 16 x 1.04 millimeter (mm) land grid
Compared to RFID tags, Bluetooth
we get technical
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