CSPs, Have You Optimized Your Base Station Antenna Assets?

From attending CommunicAsia in Singapore, Mobile World Congress (MWC) in Shanghai, and Huawei’s Mobile Broadband Forum (MBBF) in Dubai, Communications Service Providers (CSPs) are clearly still optimizing their Radio Access Networks (RANs). CSPs need to ensure ubiquitous coverage and provide the necessary capacity to their users. One component of their RANs, the Base Transceiver Station (BTS) antenna, is still far from being optimized.  Fundamentally, all cellular traffic goes through the BTS antenna. As a result, the performance of the BTS antenna has a very material impact on the overall experience of the mobile network. Furthermore, CSPs are facing demands to adopt green and sustainable practices, where antennas can make a substantial contribution.

To optimize their RANs, CSPs will need to go beyond deploying “more base stations.” CSPs will need to continue maximizing their network performance and deploying the best equipment for their mobile networks.

Evolving from 2D to 3D Radiation Patterns

BTS antennas do not just simply cover a cell site. The signal strength and coverage pattern will vary from antenna to antenna and vendor to vendor. There is the “Two-Dimensional (2D) radiation pattern,” but it is increasingly becoming clear that CSPs operate in a Three-Dimensional (3D) space where the BTS antenna signal needs to be projected and received from low-rise buildings, skyscrapers, and from inside shopping malls. Moving from analyzing an antenna’s “2D radiation pattern” to its “3D radiation pattern” will allow the CSP to evaluate antenna performance more comprehensively. The advancement of test equipment and computational technologies has enabled the industry to generate 3D patterns, which was previously costly and difficult to obtain. The 3D radiation pattern provides more in-depth information about the performance of a base station antenna. The 3D radiation pattern also provides additional information such as Radio Frequency (RF) efficiency, coverage efficiency, interference indicators, and beamforming efficiency, among many others.

Fully comprehending the 3D RF and spatial coverage characteristics of the intended base stations’ antennas would allow CSPs to optimize the coverage of base station antennas and, thus, ensure that the network performance is fully realized. Adjustments could then be made to the horizontal beam and/or vertical beam characteristics to best suit a particular environment or locale. With such capabilities, RF planners will be able to adapt their mobile networks rapidly and effectively for future and scenario-based demands.

Base Station Antenna Innovations

We have observed the evolution from mechanical integration to electronical integration where a single Massive Multiple Input, Multiple Output (mMIMO) antenna can be seamlessly integrated into the back of a passive cellular BTS antenna to deliver to the CSP active-passive antennas that offer CSPs more versatile antennas in a more compact form factor. As capacity demand and performance demand continue to grow at the cell site, the passive base station antenna will need to make provisions for future mMIMO configurations such as 64T64R or even higher. While catering for future demand for mMIMOs, the passive base station antennas also need to ensure future upgradability via hardware or software (e.g., incorporating beamforming functionality). With an increasing demand for mobile networks, it has become increasingly important for base station antennas to adopt higher order MIMO configurations; for example, by transitioning from a 4T4R to an 8T8R configuration for passive antennas. A perpetual challenge faced by outdoor mobile networks is the ability to provide a sufficient link budget to devices indoors. With an 8T8R antenna, the sensitivity to transmit and receive signals indoors is more effective.

Embedding Sustainability into the Antenna

For CSPs, sustainability and operational costs are perennial concerns especially in our current era. Better information, which enables accurate deployment of antennas, can help reduce the energy used to deliver the same performance. This will help CSPs align their Environmental, Social, and Governance (ESG) goals with their efforts to make the network greener and, at the same time, improve the efficiency and performance of the mobile networks for end users. Analyzing and interpreting the 3D radiation pattern will enable telco operators to evaluate and optimize the energy efficiency, link budget, and coverage characteristics being delivered to end-user devices.

Green initiatives do not only include energy usage. Another key challenge for CSPs lies with “scope 3 emissions.” Scope 3 represents the indirect Greenhouse Gas (GHG) emissions from a company’s value chain. There are two main ways to tackle the environmental impact: 1) reduce the manufacturing and materials impact a product has on the environment; and 2) prolong the life span and usability of a single product. To prolong the life span of base station antennas, vendors will need to look deeper into the material science domain to understand and choose the right materials to meet both the sustainability and the performance requirements. The life span of base station antennas can be prolonged by making the antennas more modular and ensure they can deliver greater reconfigurability, thus adapting to new application scenarios.

Base station antennas lie at the heart of many discussions about mobile network performance, cost, and sustainability. While the overall appearance of the antenna has not changed radically over the past decade, it houses a distinct range of novel innovations. With the increasing demands on the mobile network, CSPs must seek further operational efficiencies in every part of their networks. ABI Research estimated that CSPs spent US$3.75 billion on passive antenna upgrades in 2022 and US$22 billion on active antennas during the same period. This is a significant investment by CSPs, and they need to make sure they secure the maximum Return on Investment (ROI). All traffic goes through the base station antenna. As antenna vendors continue to push the boundaries of innovation and unlock new network functionalities, CSPs should not forget the importance and value of their base station antennas. The mobile network is only as robust as its weakest network asset.