Ubiquitous connectivity is increasingly becoming a “must-have” in the modern world.
Connecting people and everything, no matter where they are, has always been the main goal of wireless communications. Whether it is people talking on their mobile phones, vehicle communication (V2X) platforms helping cars negotiate traffic turns, or Internet of Things (IoT) devices monitoring smart factories, today’s wireless systems are striving to realize that dream.
This power means that ubiquitous connectivity—systems capable of seamlessly using satellite, cellular, and local area networks to maintain a fast, secure, and reliable online connection—is no longer a “nice-to-have” feature but rather a “must-have!”
For the engineers building these technologies, the challenges of designing wireless systems optimized for ubiquitous connectivity have grown along with their capabilities. These include ensuring a device’s compliance with standard protocols for system and device interoperability; optimizing multidomain system parameters that integrate algorithms, antenna, array, and RF transceiver design choices; and verifying the designs of hardware prototypes with automated over-the-air tests and realistic channel and impairment models.
Fortunately, techniques and best practices exist that engineers can use to design, model, and test these systems, ensuring they work together to provide businesses and consumers alike with not only wireless access, but with true ubiquitous connectivity.
The evolution of wireless
From a technical perspective, the concept of ubiquitous connectivity is nothing new. However, it’s been a challenge to execute for economic, technical, and physical reasons. Economically, the number of access points has been historically limited by cost and therefore reserved mainly for high-density population areas. Technically, high throughput links could not be constructed seamlessly over a variety of ranges and distances, and each technology has catered to its own niche market. And, physically, each communication link is limited by the interference provided by other systems using the same or adjacent spectra. This has made coordination between various systems a necessity.
While modern high-level wireless systems have overcome many of these challenges—for example, Low Earth Orbit (LEO) satellites are more cost-effective than their Medium Earth Orbit (MEO) and Geostationary Orbit (GEO) counterparts, with their signals capable of providing substantial throughputs at large distances—other challenges remain.
5G, Wi-Fi, and satellite-based communication devices, for instance, rely on multi-user multiple-input and multiple-output (MIMO) beamforming technology to reach users in the service area. MIMO and beamforming-enabled devices are equipped to send and receive multiple signals, necessitating engineers to optimize the use of multiple frequency bands at once. However, this requires constant monitoring of available signal space and precise scheduling as well as channel modeling and measurements on both ends of the link to connect two devices.
When designing for ubiquitous connectivity, engineers have typically designated Wi-Fi systems for shorter-range and cellular systems for longer-range communications. These heterogenous types of networks can operate in tandem, so that, for example, signals beamed to a congested cellular service areas can be offloaded to a Wi-Fi service network and vice versa.
Bluetooth also has a role to play in ubiquitous connectivity. While not meant to be part of a high-throughput wireless network, the low power and ISM (industrial, scientific, and medical) band usage of its basic rate, enhanced data rate, and Bluetooth low energy (BLE) standards makes the platform ideal for sending short-range signals. Engineers can leverage the short-range signals provided by Bluetooth as they best indicate whether a device needs to connect to the internet. Alternatively, Bluetooth can also help engineers save bandwidth and keep devices offline when they do not need to be connected.
Ensuring each of these types of networks—broad area networks such as satellite links, cellular wide area networks including 4G and 5G, local area networks (Wi-Fi), and personal area networks such as Bluetooth—are in sync providing ubiquitous connectivity requires extensive testing. For engineers working on these problems, such testing is better conducted through modeling and simulation than with live equipment. This is where the value of large-scale simulation platforms becomes apparent.
How simulation can help achieve ubiquitous connectivity
Solving the challenge of ubiquitous connectivity requires engineers to not only understand the relationships and interferences between all wireless communications protocols and standards in place today, but also to test the standards’ compatibility with each other.
Engineers can use large-scale modeling and simulation tools such as MATLAB and Simulink from MathWorks to design, model, test, and analyze systems before deployment, thereby ensuring the reliability of their systems long before a physical device is built.
For example, a key challenge when developing cellular network systems is the number and complexity of parameters associated with each mode of operation. Engineers need to understand that each parameter needs to be tested against a variety of channel conditions that can occur in a typical cellular network. If all the testing conditions are not met, the system cannot be certified.
To address this, engineers can use simulation platforms to provide an environment that makes reviewing all potential parameters and evaluating them against other systems easier, faster, and more reliable than physical testing. Faster testing methodologies are largely possible due to the advancement of technologies included with MATLAB and Simulink, such as ease of test waveform generation and use of automatic C code generation, along with the use of graphics processing units (GPUs) and parallel computing for accelerating simulations.
Of course, multi-user MIMO and beamforming systems are only as effective as their ability to accurately point to and connect with target devices. This necessitates simulation platforms such as MATLAB and Simulink to make the task of verifying accurate positioning and localization easier. These solutions not only provide engineers with industry-standard compliant tools generating individual signals including Bluetooth, 5G, LTE, and Wi-Fi, but they also provide a visualization and testing environment enabling them to see the effect of indoor and outdoor RF propagation on maps. This will help them ensure that the connections between multiple devices are accurate.
Ubiquitous connectivity is increasingly becoming a “must-have” in the modern world. This ultimately means that simulation platforms too will have to adapt to remain essential for engineers as they design systems capable of seamlessly using a multitude of modalities, including satellite, cellular, and local area networks, all while maintaining fast, secure, and reliable online connections.