ITU-R urges Member States to take measures to prevent interference with radio navigation satellite service (RNSS) signals and receivers


Harmful frequency interference poses a significant and growing threat to critical infrastructure and safety services used every day, from commercial aviation to energy distribution to satellite navigation systems.

Protecting this ecosystem is essential for the safe and satisfactory operation of the growing number of devices, applications and autonomous vehicles that rely every day on positioning and navigation systems on air, sea, and land.

One of the principal objectives of the International Telecommunication Union (ITU) and its 193 Member States is to ensure interference-free operations of radiocommunication systems.

Article 45 of the ITU Constitution requires Member States “to take the steps required to prevent the transmission or circulation of false or deceptive distress, urgency, safety or identification signals, and to collaborate in locating and identifying stations under their jurisdiction transmitting such signals.”

Call for Action to mitigate interference with RNSS signals and receivers:

Following several incidences of harmful frequency interference brought to the attention of the ITU Radio Regulations Board, a recent Circular Letter urged ITU Member States to take measures to prevent interference with radio navigation satellite service (RNSS) signals and receivers.

The RNSS is an essential component of global critical infrastructure, providing a “safety-of-life” service that must be protected from interference. It is used in GPS (the US-based Global Positioning System) and other global navigation satellite systems (GNSS) platforms, such as Europe’s GALILEO, Russia’s GLONASS and China’s BeiDou system.

Between 1 February 2021 and 31 January 2022, ITU received 329 reports of harmful interference or infringements of the Radio Regulations – the international treaty safeguarding the equitable and efficient use of the radio frequency spectrum.

Data collected by a major aircraft manufacturer shows that 10,843 radio-frequency interference events were detected globally over the same 12-month period, the circular notes. These figures were based on in-flight monitoring of GNSS receivers, which are standard onboard equipment for passenger or transport aircraft.

While most of the interference events occurred in the Middle East, several were also detected in the European, North American, African, and Asian regions.

The ITU Radiocommunication Bureau initially raised the issue of increasing interference to Member States at the 2019 World Radiocommunication Conference (WRC-19) in Sharm-El-Sheik, Egypt.

Since then, ITU has received reports about significant numbers of cases of harmful interference to the RNSS in the 1,559–1,610-megahertz (MHz) frequency band, also known as the “L1 band”.

What makes interference harmful:

Virtually all radio systems experience some interference. At very low levels, this can be considered acceptable or tolerable.

Harmful interference occurs when a radio system receives unwanted energy to an extent that inhibits the functioning of a radio-navigation service – such as those used onboard ships or aircraft – or seriously degrades, obstructs, or repeatedly interrupts any radiocommunication service that is operating in accordance with the Radio Regulations.

For example, harmful interference in the L1 band can disrupt the onboard receivers of aircraft, causing the degradation or total loss of communication for passenger, cargo, and humanitarian flights. In some cases, harmful interference in this frequency band can even cause RNSS receivers to provide misleading information to pilots, presenting a major safety risk.

Harmful interference with RNSS or GNSS signals – whether it is deliberate or inadvertent – constitutes a violation of the Radio Regulations, which state that “frequencies used for the safety and regularity of flight require absolute international protection from harmful interference and that administrations undertake to act immediately when their attention is drawn to any such harmful interference.”

One major source of such disruptions is unnecessary radio transmissions. But the interference prohibition also applies to the use of jamming devices, commonly referred to as “GNSS jammers,” “signal blockers” or “privacy jammers”.

Provision No. 15.1 of the Radio Regulations states that “all stations are forbidden to carry out unnecessary transmissions, or the transmission of superfluous signals, or the transmission of false or misleading signals.”

Handling harmful interference:

ITU’s Radiocommunication Bureau receives hundreds of interference reports each year. But ITU – the United Nations specialized agency for information and communication technologies – is not alone in the battle to identify the sources of these potential cases and avert or eliminate resulting problems.

ITU collaborates with affected administrations and industry sectors, as well as with other UN agencies like the International Civil Aviation Organization (ICAO) and the International Maritime Organisation (IMO).

While the Radiocommunication Bureau strives to deal with each report within 48 hours, the vital role of preventing harmful interference falls to governments around the world.

To mitigate this critical international issue, ITU asks its 193 Member States to take the following steps:

  • Reinforce the resilience of navigation systems to interference by using technologies with multi-frequency/multi-system receivers and anti-jamming capabilities;
  • Increase collaboration between radio regulatory, military, aviation, and law enforcement authorities;
  • Reinforce civil-military coordination to address interference risks associated with RNSS testing and conflict zones;
  • Retain essential conventional navigation infrastructure for contingency support in case of RNSS outages; and
  • Develop mitigation techniques for loss of services.


New ITU-T Standards for IMT 2020 (5G) + 3GPP Core Network Systems Architecture

New ITU-T standards related to “5G”:

ITU-T has reached first-stage approval (‘consent’ level) of three new international standards defining the requirements for IMT-2020 (“5G”) network systems as they relate to network operation, softwarization and fixed-mobile convergence.

The standards were developed by ITU-T’s standardization expert group for future networks, ITU-T Study Group 13.

Note: The first-stage approvals come in parallel with ITU-T Study Group 13’s establishment of a new ITU Focus Group to study machine learning in 5G systems.

End-to-end flexibility will be one of the defining features of 5G networks. This flexibility will result in large part from the introduction of network softwarization, the ability to create highly specialized network slices using advanced Software-Defined Networking (SDN), Network Function Virtualization (NFV) and cloud computing capabilities.

The three new ITU-T standards are the following:

  • ITU Y.3101 “Requirements of the IMT-2020 network” describes the features of 5G networks necessary to ensure efficient 5G deployment and high network flexibility.
  • ITU Y.3150 “High-level technical characteristics of network softwarization for IMT-2020” describes the value of slicing in both horizontal and vertical, application-specific environments.
  • ITU Y.3130 “Requirements of IMT-2020 fixed-mobile convergence” calls for unified user identity, unified charging, service continuity, guaranteed support for high quality of service, control plane convergence and smart management of user data.

ITU’s work on “International Mobile Telecommunications for 2020 and beyond (IMT-2020)” defines the framework and overall objectives of the 5G standardization process as well as the roadmap to guide this process to its conclusion by 2020.

ITU’s Radiocommunication Sector (ITU-R) is coordinating the international standardization and identification of spectrum for 5G mobile development. ITU’s Telecommunications Standardization Sector (ITU-T) is playing a similar convening role for the technologies and architectures of the wireline elements of 5G systems.

ITU standardization work on the wireline elements of 5G systems continues to accelerate.

ITU-T Study Group 15 (Transport, access and home networks) is developing a technical report on 5G requirements associated with backbone optical transport networks. ITU-T Study Group 11 (Protocols and test specifications) is studying the 5G control plane, relevant protocols and related testing methodologies. ITU-T Study Group 5 (Environment and circular economy) has assigned priority to its emerging study of the environmental requirements of 5G systems.

ITU-T Study Group 13 (Future networks), ITU’s lead group for 5G wireline studies, continues to support the shift to software-driven network management and orchestration. The group is progressing draft 5G standards addressing subjects including network architectures, network capability exposure, network slicing, network orchestration, network management-control, and frameworks to ensure high quality of service.


The “5G” wireline standards developed by ITU-T Study Group 13 and approved in 2017 include:



“5G” Core Network functions & Services Based Architecture:

The primary focus of  ITU-R WP5D IMT 2020 standardization efforts are on the radio aspects (as per its charter).  That includes the Radio Access Network (RAN)/Radio Interface Technology (RIT), spectral efficiency, latency, frequencies, etc.

To actually deliver services over a 5G RAN, a system architecture and core network are required. The core network provides functions such as authentication, session management, mobility management, forwarding of user data, and (possibly) virtualization of network functions.

3GPP Technical Specification (TS) 23.501 — “System Architecture for the 5G System” — is more commonly referred to as the Service-Based Architecture (SBA) for the 5G Core network.  It uses service-based interfaces between control-plane functions, while user-plane functions connect over point-to-point links. This is shown in the figure below. The service-based interfaces will use HTTP 2.0 over TCP in the initial release, with QUIC transport being considered for later 3GPP releases.

Service-Based Architecture for 5G Core
Source: 3GPP TR 23.501, July 2017, Figure 4.2.3-1
Source: 3GPP TR 23.501, July 2017, Figure 4.2.3-1
Various aspects of this new core network design are described in a new Heavy Reading white paper — Service-Based Architecture for 5G Core Networks.

There are many aspects to this, but the white paper highlights:

  • How the idea of “network function services” (3GPP terminology) aligns with the micro-services based view of network service composition
  • How operators may take advantage of decoupled control- and user-plane to scale performance
  • How the design might enable operators to deploy 5GC functions at edge locations, such as central offices, stadiums or enterprise campuses

The first 5G core standards (really specifications because 3GPP is not a formal standards body) are scheduled to be included in 3GPP Release 15, which “freezes” in June next year and will be formally approved three months later. This will be a critical release for the industry that will set the development path of the 5G system architecture for years to come.

Download white paper:  Service-Based Architecture for 5G Core Networks

Editor’s Note:


“The 3GPP Technical Specifications and Technical Reports have, in themselves, no legal standing. They only become “official” (standards) when transposed into corresponding publications of the Partner Organizations (or the national / regional standards body acting as publisher for the Partner).”