Coping with congestion


According to the World Health Organization, over 55 per cent of the world’s population live in urban areas, a proportion that is expected to increase to 68 per cent by 2050. Cities are being stressed like never before and the supporting infrastructure is becoming more congested, yet connectivity remains limited. Here, Walter Magiera, Chief Commercial Officer at Filtronic, an expert in RF technology, explains how mmWave enables high-performance and reliable connections in densely populated areas.

The traditional approach to cell tower deployment involved the installation of tall towers that could cover large geographic areas. However, with the increasing demand for wireless data in densely populated areas, this approach has become less effective.

The new approach involves the use of towers that are smaller in size and use remote radio heads (RRH), which are radio frequency (RF) components in cellular networks separated from baseband units that can handle the complexities of urban life and provide better coverage in densely populated areas. These towers are often discreetly incorporated into existing structures, such as rooftops or even church steeples, making them less obtrusive than traditional cell towers.

Today, we use wireless technology every single day in a multitude of formats. This means that millions, if not billions, of RF signals are travelling at different frequencies, with each assigned to a specific communication channel or service.

However, as the number of RF signal generating apparatus increase and user base grows, the spectrum becomes more congested. This means that signals can overlap in densely populated areas or locations with high device usage, leading to capacity and interference issues.

Adaptive filtering

As governments around the world approve and adopt new frequency bands, the airwaves will have an intricate and complex matrix of interference to contend with. In an effort to mitigate that interference, governments and mobile network operators will need to proactively address this by deploying combining and filtering technologies.

This is where the expertise of RF-to-mmWave component manufacturers come in, as Filtronic provides adaptive filtering technologies, a signal processing technique that adjusts the characteristics of a filter in real-time based on the input signal. Filtronic are also experts in switched filter banks, which are a set of filters used to divide an input signal into different frequency components, where the selection of filters can be changed based on specific criteria.

With over 45 years of experience, Filtronic has specialised in the design and manufacturing of complex filters, helping to mitigate the risk of interference caused by congestion.


According to IoT Analytics, there will likely be more than 29 billion IoT connections by 2027. Yet IoT requires a lower transmission rate, a higher number of device connections and low-power transmission due to limited power of the terminal device.

Where diverse communication requirements arise, RF and microwave technologies can contribute to the development of options that meet the specific demands of the increasing IoT connectivity.

For instance, in scenarios such as hydrological monitoring and environmental protection, where terrestrial wireless communication falls short, non-terrestrial communications become more critical. Transmitting and receiving large packages of data becomes a limitation at lower frequencies. mmWave also has its challenges, specifically propagation and power, but this is where Filtronic’s E-band Solid State Power Amplifiers (SSPA) become necessary.

For example, The E-band SSPA Taurus is specially designed to address the complex challenges faced by today’s terrestrial and non-terrestrial wireless networks, providing reliable and high-performance communication components that ensure connectivity even in challenging environments.

Here, the Taurus amplifier boasts double the available output power than its predecessors, combining the power of two Cerus 8 E-Band amplifier modules. These amplifiers each contain eight GaAs pHEMT PA MMICs, with their power efficiently combined in waveguide to deliver maximum output.

Its all about mmWaves

Lower frequencies face limitations with wireless communication due to a restricted bandwidth, leading to slower data rates.

Let’s use a busy motorway as an analogy, which is four lanes wide. Be it in an already densely populated area, or one that is increasing rapidly, more people joining the motorway increases the demand for faster speeds. However, the existing layout has reached a saturation point, thereby creating a bottleneck.

This is exactly how a smart city will work if it relies on older technologies. From the growing demand for connectivity and higher data speeds, the demand puts pressure on the existing communication infrastructure, leading to signal congestion and slower data rates.

Using mmWave frequencies, such as E-band and W-band, are like adding a whole new German Autobahn, the federal controlled-access highway that helps to ease congestion and speed up the traffic.

E and W-band frequencies provide a broad bandwidth that supports high data rates, allowing for higher data rates and quicker data transmission. In smart cities this additional band width is crucial as a network of devices must be able to communicate and exchange data quickly and without disruption — be it vehicles, on-street sensors or home appliances.

In addition, E and W-band wireless communication systems can offer a cost-effective alternative to traditional fibre optic solutions. Deploying fibre optic cables is expensive, disruptive to communities and time-consuming. This is especially true in challenging terrains or urban environments where the planning process is extensive.

Designing and deploying wireless links utilising E and W-band can provide a quicker and more flexible deployment option, saving on installation costs and offering scalability, with no reduction in performance. mmWave frequencies, such as E and W-band, can replicate connectivity often considered as ‘Fibre in the Sky’, replicating high quality connectivity without the need for ground-based infrastructure.

E-band’s low-latency attribute is primarily due to the speed at which electromagnetic signals, including those in the millimetre-wave spectrum, travel. Electromagnetic signals, such as those used in E-band, move at the speed of light, ensuring near-instantaneous transmission. This is particularly advantageous for applications requiring real-time interactions, like financial transactions, online gaming and video conferencing.

As for smart city applications, low latency is especially crucial for the successful implementation of emerging technologies, including IoT and autonomous vehicles. Regarding the latter, vehicles rely on low-latency communication to make split-second decisions, enhancing safety and efficiency on the roads.

Transceivers, like Filtronic’s Morpheus X2 modules, contain all the transmit and receive functions necessary for the RF section of an E-Band link, providing people and businesses with more bandwidth and high-capacity data transmission.

E-band’s capabilities in high data rates, cost-effective deployment and low-latency communication contribute significantly to advancing connectivity and removing interference in the smart city infrastructure.

This makes it a critical component for the world’s population living in urban areas, which, if estimates are to become true, will increase to 68 per cent by 2050. Smart cities of the future will rely on mmWave, with bands such as E-band and W-band becoming ever more critical to solving the congestion problem.