Energy management is now an essential component of operating a network, particularly during peaks and troughs in demand. But it is also essential to test network protocol resilience and performance on return to service in multiple scenarios, as highlighted by the huge power outage that affected Portugal and Spain earlier this year. How can you be sure that services function as required when they are restored?

The impact of power outages on network resilience cannot be understated. The well-publicised disruption connectivity in Spain and Portugal on 28 May 2025 is a classic example. It closed travel infrastructure, schools, and businesses, and brought online activities to a halt. Parts of France were also affected, as was Morocco – Orange Maroc posted on its X feed: “Internet traffic has been disrupted following a massive power outage in Spain and Portugal, which is affecting international connections.” 

The power outage had far-reaching consequences. In Portugal, internet traffic dropped dramatically – reaching a low of 90% in comparison to the previous week, while in Spain, it declined by around 80% when compared to the same time period.

Perhaps most importantly, in some areas, access to emergency services via 112 was disrupted – Andalusia, Navarra and the Basque country were all impacted. 112 is a mandated service and operators need to ensure that they can restore access as quickly as possible.

Power outages can have a significant impact on network performance

As mentioned, international interconnectivity was also severely impacted, with many operators having to start emergency backup generators to keep services running. In many regions, alternative telephone numbers had to be rapidly introduced to provide access to emergency services.

The fault was blamed on the Spanish electricity grid, and was, apparently, the result of extreme temperature variations in the interior of Spain – a phenomenon known as “induced atmospheric vibration”. However, this has since been denied. An incident report presented to Spain’s Council of Ministers in June suggests that Spain’s grid operator miscalculated the correct energy mix, which led to a lack of requisite voltage.

A voltage surge created by an escalation in demand then led to a cascade of power plant disconnections and a massive power outage across the Iberian Peninsula.

The power outage was corrected by the end of the day, but it shows the severe impact that failures in energy supply can have on connectivity. Regardless of why it happened, or how, the incident highlights the significant importance of energy management and the need to test resilience protocols – particularly when considering mandatory services, such as access to emergency help and support.

Return to service testing is essential for assuring customer experience and access to 112

The incident made news around the world for obvious reasons, but as well as ensuring the appropriate level of power to the network, and developing failsafe backups, operators also need to cut costs.

Sustainability, global emissions targets, and the soaring price of energy all mean that energy management in mobile networks, of any generation, has become a pressing issue. Optimising energy efficiency, while ensuring performance (such as throughput, capacity, latency, and so on), while assuring QoS and QoE is therefore essential.

Energy management policies, then, need to be carefully implemented – and also considered during incidents that seriously degrade or disrupt network performance, such as the power outages in Spain and Portugal.

For daily, energy management, one of the most important issues is to ensure that power demand can be limited during times of low demand and boosted when traffic surges. At the same time, it’s essential to ensure that the appropriate KPIs, SLAs and performance parameters are restored on return to service (RTS) — whether that’s an intended reduction of network power (during low demand) or because of a power outage such as that which occurred in Iberia.

While energy management is focused on saving money and meeting CSR obligations, network resilience protocol testing is essential for testing how a network behaves under stress – such as power outages, attacks, or other unexpected incidents – in a proactive manner. It enables operators to identify weaknesses, maintain functionality and improve recovery systems so that RTS occurs quickly… and to the required (previous) performance level. 

Network resilience testing might involve, for example:

• identifying and testing potential failure scenarios (such as power outages or unexpected surges in demand)
• emulating system failures or cyberattacks
• evaluating network performance before, during and after RTS
• identifying bottlenecks
• root cause analysis
• implementing redundancy
• performing active monitoring

And much more.

How Emblasoft Evolver can help

Emblasoft Evolver can help operators with their resilience and power management protocols. It provides comprehensive  functional, load and active monitoring capabilities to track KPIs and service performance when network resources are restored to full power – either during managed energy conservation processes, or whether following unexpected incidents.

This topic is explored in our recent briefing paper “Why performance testing and active monitoring across mobile network power cycles for both expected and unexpected downtime is now critical”, which you can read, here.

Evolver can also ensure that RTS performance returns to original levels after any change, such as an intended lowering of performance during low-traffic times (and for high-traffic surges), a power outage, or a cyberattack.

It enables individual node testing and assurance in isolation or in parallel to validate end-to-end functionality and performance at any point in the energy/traffic cycle.

Evolver can also query the servers hosting the UPF to obtain CPU usage and power consumption data. So, as operators seek to manage energy as a KPI, while delivering SLAs, Evolver enables them to check that performance is as expected.

The incident in Portugal and Spain highlights the importance of network resilience protocol testing. It’s not just everyday services, like mobile internet access – it’s crucial, regulated services, like emergency call that can be impacted.

Getting systems back online or increasing power levels is essential – and so you need the right tools to ensure that your protocols for restoring services function correctly – and the ability to model different scenarios to ensure readiness.

To find out how Emblasoft Evolver can help you ensure optimum energy efficiency and performance simultaneously, while preparing for expected and unexpected network situations, contact us today.