Resolution 770 After WRC-23

The World Radiocommunication Conference (WRC) in 2019 approved Resolution 770 which can be used to determine whether non-GSO FSS systems operating in parts of Q/V band meet the requirements of Article 22 to protect GSO networks. The Resolution included parameters of generic links and an algorithm to calculate the increase in unavailability and loss of throughput due to interference, which could then be compared against the 3% limits in Article 22.5L. During the cycle from WRC-19 to WRC-23, this algorithm was examined further and, while found to be basically sound, minor adjustments were made. This Technical Note (TN) describes these changes and the new regulatory framework.

Modelling Interference from 5G System into Radar Altimeters

Portions of the frequency band 3.7 - 4.2 GHz has been reallocated to flexible use including 5G applications. This is close in frequency to the 4.2 - 4.4 GHz band used by radar altimeters on civil aircraft, which is a critical application involving safety of life. Recently there has been concern of the potential of harmful interference from 5G systems into these radar altimeters, in particular when aircrafts are near airports at lower heights close to terrestrial transmitters.

Modelling D2D Systems using Visualyse Professional or Visualyse Interplanetary

There is currently significant interest in the satellite and mobile industries in the potential to provide communication services from satellites direct to users with unmodified handsets. These types of systems are sometimes called direct-to-device (D2D), non-terrestrial networks (NTN) or supplementary coverage from space (SCS) and could involve a constellation of low Earth orbit satellites with large antennas that have the ability to provide such a service. But this brings in technical and regulatory challenges, from the type of services that can be provided, how to optimise coverage, capacity and throughput to the potential for interference to other services including terrestrial networks. This White Paper shows how these types of studies can be undertaken using the Visualyse Professional and Visualyse Interplanetary tools.

Visualyse Interplanetary: General Satellite Dynamics Update and Lagrange Points

Visualyse Interplanetary has recently been updated with improved general satellite dynamics definition and ability to specify spacecraft to be located at a Lagrange Points, as described in this Technical Note (TN).

About Transfinite Systems

We are one of the leading consultancy and simulation software companies in the field of radiocommunications. We develop and market the leading Visualyse products:

• Visualyse Professional
• Visualyse Interplanetary
• Visualyse GSO
• Visualyse EPFD and associated PFD Mask Generator Tool