The nature of 5G wireless communications infrastructure means that mobile network operators place cell sites closer together than has been common with 4G wireless communications. These denser network configurations often position radios on poles, exposing them to environmental stressors that may affect performance. The networks synchronize each radio with other radios in the same time domain. Any time difference from one tower to the next results in a dropped signal. In comparison with 4G’s time difference between radio towers of 1.5 microseconds (µs), enhanced 5G features such as multiple-input multiple-output (MIMO) antenna technology, carrier aggregation and RF beam-steering have an even smaller timing error margin — just 130 nanoseconds (ns).
Manufacturers use newer technologies to address the environmental challenges in the 5G infrastructure. An example is micro-electro-mechanical systems (MEMS) for timing. First introduced 15 years ago, these devices have many characteristics that make them ideally suited to handling environmental stressors. They measure as much as 3,000 times smaller and weigh less than conventional timing technologies, making them less susceptible to mechanical forces such as shock and vibration. For example, they demonstrate 40 times better vibration resistance than quartz components and 20 times better resistance to temperature and airflow changes.
The use of MEMS and other technologies reflects the importance of timing. It is the heartbeat of an electronics system, because the vibrating, mechanical element must provide a precision reference even if used in an uncontrolled or harsh environment. Consequently, a timing component has to be rugged and reliable to withstand mechanical forces and environmental stressors.
Although electronic components make up most of a mobile network system, the exceptions are sensors and timing devices, which are both mechanical and electronic. This is why outdoor locations can present design dilemmas. Nature springs from a mix of mechanical and electrical forces, leading designers to select the most suitable components that may lie on the critical path to achieving the system’s reliable operation in these conditions.
Both consumers and industrial customers will benefit from 5G’s high throughput, low latency operation. Compared with 4G communications, 5G carries expectations of increasing the bandwidth 10-fold and of having 50 times lower latency. This leap in performance means that data and video will download as much as 10 times faster, using 10 times more bandwidth. The lower latency— just 1 to 10 milliseconds (ms) — will enable prompt updates for remote monitoring in health care and rapid responses to changes in traffic conditions in advanced driver assistance systems (ADAS) and, later, fully autonomous vehicles. The low latency rate will enable applications that rely on time- sensitive operation, such as autonomous vehicles in smart cities, and telemedicine.
In industrial applications, machine-to-machine (M2M) connectivity will advance smart factory, machine learning, artificial intelligence (AI) or Industry 4.0 systems to reduce downtime and improve productivity via intelligent networks.
The Move to Outdoors
Initially, innovators deployed precise, mission critical electronics indoors, in temperature-controlled environments. Later, the electronics moved outdoors as cell phones and wearable devices became popular, but they still were connected with a human, controlling temperature and vibration.
A new era of communications requires a new approach using newer technologies. With the advent of 5G, the 10,000-fold increase in data volume in vehicles alone will require placing more networking equipment outdoors, exposed to the environmental forces of nature, to be closer to the consumer. The proliferation of the internet of things (IoT) as part of the smart city infrastructure also increases the need for electronics sited in uncontrolled environments — electronics nevertheless expected to operate reliably and with minimal intervention.
In these locations, electronics will be subject to multiple forces of nature, but with no margin for error. Devices will be part of networks that include exposed radio and antennas or moving nodes in transport systems. They may be subjected to environmental stresses, such as shock, vibration, temperature changes, wind, lightning and high humidity. Engineers and developers are acutely aware that in safety-critical applications, such as autonomous vehicles, no one will tolerate failure in the radio-to-radio transmission of vital data between nodes on the network.
In order to realize a connected world, based on a fast, reliable 5G infrastructure, development of new technologies that need to exhibit environmental resilience has accelerated.
Ready and eager 5G consumer and commercial users expect the industry to ensure that it can supply effective outdoor electronics as part of the 5G infrastructure. This means that manufacturers must design all electronic equipment with environmental resilience in mind. Reliable, efficient systems increasingly will use newer, more technologically advanced components for this new wave of electronic equipment.
Only when suppliers make reliable, proven components available and ready for deployment can we capitalize on the new opportunities 5G presents.
Markus Lutz is founder and CEO of SiTime. Visit www.sitime.com. SiTime provides MEMS timing solutions for communications and enterprise.