Imagine you’re on a long-haul flight from London to Johannesburg. The pilot depends on seamless satellite communications for weather updates, navigation, and communication with ground control. Suddenly, a signal disruption caused by mobile broadband interference scrambles crucial data. The aircraft loses navigation accuracy, forcing the crew into emergency procedures to avoid disaster.
This scenario underscores the potential for disaster if the resilient L-band satcom link is not protected, ensuring that air travel remains safe and dependable and preventing worst-case scenarios.
Lost at Sea with No Lifeline
A fishing vessel off the Cape coast encounters a severe storm. The crew activates their emergency distress beacon, sending a signal via satellite to the rescue coordination center. But interference from newly deployed IMT services scrambles the signal, delaying emergency response. In a situation where minutes can mean the difference between life and death, safeguarding the L-band ensures seamless emergency communications and saves lives at sea.
A City Cut Off During a Natural Disaster
A powerful earthquake hits a remote town in South Africa, taking down all terrestrial communication infrastructure. Emergency responders rely on satellite-based communication systems operating in the L-band to coordinate relief efforts. However, interference from IMT services renders these satellite links unreliable, delaying crucial medical aid and supply chains. Ensuring interference-free L-band communications means communities can stay connected when most needed.
A Cybersecurity Breach in National Defence
South Africa’s military operations depend on secure satellite communications for intelligence gathering and strategic coordination. A cybercriminal group or foreign entity exploits the weakened L-band spectrum due to unchecked IMT expansion, causing disruptions in encrypted defence communications. The inability to coordinate effectively puts national security at risk. By protecting this spectrum, South Africa ensures that its defence forces remain operationally ready and secure.
These examples highlight the criticality of the satellite communications links in the L-band spectrum at 1.5 GHz.
Managing this radio spectrum is a crucial aspect of national telecommunications policy, balancing the needs of essential safety-of-life applications and commercial mobile broadband services. As the Independent Communications Authority of South Africa (ICASA) considers extending International Mobile Telecommunications (IMT) operations into the 1492-1518 MHz spectrum band, industry experts and stakeholders warn of significant risks to existing aviation, maritime, satellite, and national security services. The urgency of preserving the integrity of the L-band is not just a technical necessity but a matter of public safety and economic stability.
The Importance of the L-Band
Without a doubt, the L-band (1-2 GHz) has long been a critical resource for satellite communications given the band propagation characteristics and its resilience to operate in any climatic conditions. For essential services including:
- Aviation safety: Air traffic management and navigation rely on adjacent frequencies for safe and efficient air travel.
- Maritime operations: The Global Maritime Distress and Safety System (GMDSS) ensures ships at sea maintain reliable distress communications.
- Land Mobile services: Providing emergency response, disaster relief, and rural connectivity across Africa.
- National security: Defence communications operate in adjacent bands, and interference could compromise mission-critical operations.
- Scientific and Environmental Monitoring: The L-band supports key scientific applications, including weather monitoring, earth observation, and climate research, which could be severely impacted by spectrum congestion.
These services depend on an interference-free environment, and ICASA’s proposal to extend IMT services beyond 1492 MHz could risk disrupting these essential operations.
The Risks of Extending IMT Beyond 1492 MHz
1. Aviation and Maritime Safety at Risk
As a signatory to the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO) agreements, South Africa must ensure that its spectrum policies do not endanger aviation and maritime safety. The 1518 MHz band is used for aircraft telemetry, navigation, and control, and extending IMT to 1518 MHz could introduce harmful interference, leading to flight delays, communication failures, and increased accident risks.
Similarly, the maritime sector depends on L-band frequencies for distress signals and emergency communications. South Africa’s Rescue Coordination Centre (RCC) covers vast maritime zones, and interference in this spectrum could hinder emergency response operations, endangering lives at sea.
2. Disrupting Satellite-Based Emergency and Rural Connectivity
Satellite operators rely on L-band frequencies to provide uninterrupted communication services in remote and underserved regions. In disaster scenarios, these services are crucial for coordinating rescue operations and ensuring connectivity when terrestrial networks fail. Interference from IMT services beyond 1492 MHz could degrade these vital services, leaving vulnerable communities at risk.
3. Economic and Strategic Consequences
The economic ramifications of disrupting L-band satellite services extend beyond safety concerns. Sectors such as mining, agriculture, logistics, and aviation depend on seamless satellite connectivity for operations. South Africa also risks non-compliance with global spectrum management frameworks, potentially impacting trade relations and international cooperation.
Additionally, countries that have assigned spectrum without thorough impact assessments have faced severe economic consequences due to service disruptions, costly mitigation efforts, and increased regulatory disputes. A premature shift to IMT in this band could necessitate expensive interference mitigation solutions, placing unnecessary financial burdens on affected industries.
4. National Security Implications
Defence agencies also use the L-band for encrypted communications, remote operations, and intelligence gathering. Allowing IMT services to extend beyond 1492 MHz could create vulnerabilities in national security communications, potentially exposing critical systems to signal degradation or unauthorized access. Given South Africa’s role in regional peacekeeping and security coordination, maintaining an interference-free L-band is vital for operational readiness and national sovereignty.
The Call for Action: A Stakeholder Seminar on L-Band Spectrum Protection
To address these pressing concerns, a one-day multi-stakeholder seminar will be held in Sandton, Johannesburg, on 25 March 2025. The event will bring together key government officials, regulators, industry experts, and international representatives to discuss the risks of extending IMT services beyond 1492 MHz and explore alternative solutions.
Conclusion: A Prudent Path Forward
While mobile broadband expansion is essential for South Africa’s digital economy, it must not come at the cost of aviation safety, maritime security, and satellite reliability. ICASA should maintain the IMT spectrum cap at 1492 MHz to protect critical services, ensure regulatory alignment with international standards, and safeguard national security.
We urge all relevant stakeholders to actively engage in it. Your contributions are crucial in shaping a balanced and responsible spectrum policy for South Africa. Your voice matters in ensuring the safe and sustainable use of the L-band spectrum.
By Wydeman Coetzee (Founder & Managing Partner ,Global Policy Partners)