Quantifying the environmental benefits of using extra mid-band spectrum to achieve mobile roll-out targets

The mobile telecoms industry is trying to minimise its carbon footprint while maximising coverage. Achieving the European Union’s (EU’s) connectivity targets – all populated areas covered by 5G by 2030 – in a way that is consistent with sustainability goals, is a significant challenge. The solution lies in a detailed understanding of the varying environmental impacts of networks as they operate in a wide range of contexts and scenarios, including population density, physical geography, technological equipment and architecture but, above all, the available spectrum bands. 

The challenge

Huawei needed a reliable quantification of the environmental impact of different deployment scenarios

To better understand the environmental impacts of meeting future wireless connectivity targets, Huawei commissioned Analysys Mason to conduct a study comparing scenarios for future 5G mobile deployments in Europe. 

Our approach 

Analysys Mason explored how spectrum affects the need for network densification 

The Analysys Mason team estimated and compared embodied and recurring carbon emissions from base stations in networks with different site densities and different spectrum availability.

We undertook a detailed analysis of the carbon emissions associated with meeting future connectivity targets via 5G and the impact of spectrum availability on those emissions. We calculated the emissions generated if the coverage targets were to be met using existing spectrum allocations and compared that with emissions generated if additional mid-band spectrum was made available. 

We modelled network deployment in terms of macro and small cells, with the EU’s 2030 objectives of 5G to all populated locations and gigabit connectivity to all homes as the demand driver for network expansion. Meeting coverage and capacity targets will require densification (in terms of the numbers of macro sites and/or outdoor small cells), but at a reduced level if additional spectrum is available. 

The network deployments modelled were representative of a typical busy European city with mobile broadband (MBB) deployment, and a typical European rural town with MBB and 5G fixed-wireless access (FWA) providing connectivity to premises.

For the urban and rural environments, we estimated total embodied and recurring carbon (kg CO2e/site/year) using current spectrum allocations and a scenario in which upper 6GHz spectrum was also available.

Assumptions were developed based on published sources and cross-checked with our vendor client.

The impact 

We provided clear evidence to inform and reshape the debate on spectrum 

Our analysis demonstrated very substantial carbon savings if upper 6GHz spectrum was available to support the EU's network expansion plans. In a typical 100km² European city, the carbon emissions of coverage using existing spectrum allocations would be 13kt of CO₂e greater in 2030 than if the mid-band spectrum is made available for 5G. This difference is largely due to the reduced need for network densification occasioned by the additional spectrum resource. 

Wi-Fi simulations found that the spectrum currently available to Wi-Fi in the 2.4GHz, 5GHz and lower 6GHz bands is sufficient to deliver the Digital Decade target. The Wi-Fi simulations found that the use of additional spectrum, such as the upper 6GHz, would not result in a lower carbon footprint for Wi-Fi installations. This demonstrates that the full savings attributable to the use of additional mid-band spectrum in mobile networks can be realised.

Our analysis and findings were written up in a published report, which is being used as an input to the ongoing debate in Europe about the future use of spectrum in the upper 6GHz band.