December 28, 2023
Various industries and businesses are using different types of IoT trackers to enhance their operations and optimize costs. Therefore, depending on the use cases of the organization we can differentiate from lower complex IoT asset trackers used for delivery and logistic companies to high end IoT trackers used in car and bike sharing programs as part of telematics control unit (TCU).
Due to its wide range of usage and global service footprint, there are many challenges that need to be considered during designing of an IoT tracker, in order to not overestimate or underestimate the product specification.
Selecting the right communication technology together with optimal communication module, GNSS module, level of ingress protection (IP) or battery size, are critical aspects that must be taken during development of an IoT tracker or TCU. In some scenarios where a cellular module cannot be used due to extreme dimension requirements, such as dimensions of a credit card, soldering the chipset (Qualcomm, MediaTek, SonyAltair, etc.) on board (COB) is used to meet firm product requirements.
In this article, we will focus on what kind of different technologies are used in order to determine the location of an IoT tracker and what aspects should be taken into account in the process of appropriate module and communication technology selection.
Communication technology and module selection
An initial step in the design process is what type of technology we want to use to send collected information to a centralized system.
LPWA technologies LTE-M and NB-IoT offer low price, better coverage and link budget due to coverage enhancement levels, lower power consumption especially when it’s combined with dedicated power consumption features introduced by 3GPP, e-DRX and PSM, that are designed to significantly reduce power consumption during inactive periods.
On the other hand, LPWA technology and modules cannot provide support for high throughput rates or advanced features. The lack of technology itself or roaming agreements between mobile network operators may represent big constraints for some markets.
Legacy technologies such as GSM, UMTS and LTE are commonly used by IoT trackers due to mature and widespread technology on a global footprint. They offer good throughput rates with worldwide roaming agreements between countries, but with higher power consumption than LPWA technology which for only battery powered IoT trackers might be a critical point during design phase.
In order to support more demanding use cases additional microcontrollers (MCUs) are required which increase complexity and price.
Over time IoT trackers have become part of other products and evolved into more complex devices such as telematics control units (TCU). As a result of more complex use cases, a few years ago so called ‘smart modules’ were introduced to the market with a goal to provide in a single package higher processing performances, more internal memory and interfaces for more advanced use cases. At the same time reducing the need for additional microcontrollers (MCUs), resulting in lower complexity during the development process and reduced billing of materials.
Smart modules are ideal for Telematics Control Units (TCU) that will provide the same benefits as an IoT tracker but will also offer wide variety of metrics and additional features, such as camera systems, AI, immobilizer or other advanced features that need to be integrated into the final solution.
Recently satellite communication modules have been introduced to the market with the main goal to mitigate extremely challenging areas without cellular network coverage. Satellite modules such as Quectel CC220A-LB incorporates connectivity offered by ORBCOMM, provides reliable global connectivity over the IsatData Pro (IDP) satellite service and features robust two-way communication, low latency, and nearly-real-time reporting capabilities. With satellite communication modules, lack of operability due to absence of connectivity is reduced to the minimum.
Bearing in mind that a module is the most expensive part of the product, it’s essential to select a proper module based on the business’s needs, environment and regions of deployment.
GNSS positioning technologies
No matter if we are talking about simple IoT asset trackers or advanced TCUs that provide tracking capabilities, the main use case of IoT trackers is to provide the location of the device to the centralized system. Depending on how accurate the location must be, there are different technologies that can be used to meet the required accuracy.
Often a signal band GNSS that uses connectivity from systems such as GPS, Galileo or GLONASS is not enough to always provide good enough accuracy and reliable positioning. Therefore, there are three different approaches to increase accuracy and reliability, and minimize effect of non-line-of-sight (NLOS) issues:
- Multi-band GNSS
- RTK positioning
- Dead Reckoning (DR)
Multi-band GNSS utilizes multiple frequencies bands to mitigate the detrimental effects of multipath. In most of the cases this has been realized through support of L1 and L5 bands, whereby the L1 is susceptible to multipath interference, whereas the L5 band exhibits superior multipath mitigation capabilities. By integrating both signals, the multi-band GNSS system can effectively discriminate between direct and reflected signals, enhancing the accuracy of positioning results.
RTK is a technique designed to counteract signal errors in GNSS positioning. It utilizes a nearby reference station with known coordinates or a network of reference stations (also known as Network RTK) to provide correction data in real-time via a carrier (cellular, broadcast radio, or satellite). The basic principle behind RTK is that it leverages the carrier-phase differential technique to compensate for common errors from the satellites and atmosphere using the correction data. This approach significantly improves the GNSS accuracy to centimeter or decimeter level in open or semi-open environments, which is important for electric scooter sharing businesses.
Dead Reckoning (DR) is a technique that provides continuous positioning even in the absence of GNSS signals. It relies on internal sensors (such as accelerometers and gyroscopes) and external sensors (such as odometers or speed pulses), to estimate the vehicle’s movement based on its initial position and subsequent changes in velocity, orientation, and position. The underlying principle of DR is that even in situations where GNSS signals are weakened or unusable due to reflections or blockages, the vehicle’s motion can still be tracked by integrating data from these sensors over time.
As we see there are many different aspects that must be considered during the development of an IoT tracker. Ikotek, a US based ODM company, has huge experience in this domain to unlock all advantages of specific technology and provide the optimal tailored solution with short time to market. At the same time reducing total cost of ownership by helping clients to select only the necessary technologies and features to meet the product requirements with no difference if we are talking about module or chip on board solutions.