Your challenge

Aircraft manufacturers often install real air traffic control (ATC) radios to perform the required verification activities. To operate these radios they need a compact voice communications system (VCS). These VCS test systems provide the relevant operational features and the exact same behavior on the radio frequency, but they do not need to deliver the same performance parameters as air navigation service providers’ operational systems.

Flexible, scalable and cost effective solutions are required.

To ensure that a new aircraft’s radiocommunications system functions with zero defects, aircraft manufacturers need to test the system and verify its functionality in an almost real environment.

Rohde & Schwarz solution

The challenges facing such test systems can be well addressed by deploying an IP-based communications infrastructure such as the R&S®VCS-4G.


Test systems for aircraft manufacturers are typically very small installations independent from any other VCS. The systems consist of one VHF, one UHF and one HF radio and at least one or two controller working positions in order to perform voice communications and relevant services, such as SELCAL. Modern IP-based VCSs with their distributed network intelligence do not require a central switching entity. They provide a pay-as-you-grow scalability that allows small systems to start with one server and one controller working position while still providing the full feature set.

Cost effectiveness

The high scalability of IP-based communications systems means that aircraft manufacturers only need to invest in the relevant basic VCS devices to build a functioning nonredundant test system. Sharing the same IP infrastructure for voice and data applications creates synergies in procurement, operation and maintenance, all of which leads to significant cost savings.

Space saving

VoIP systems migrate intelligence away from the network core to the peripheral equipment at the network edge. Purely IP-based communications systems can function with just a local area network, without a central TDM switching matrix. The extensive use of COTS hardware and small endpoints provides great flexibility in the final dimensioning of the system. The integration of VoIP radios in the overall architecture saves even more space.

R&S®VCS-4G features all these advantages of a true IP VCS and provides the aircraft manufacturer with all the benefits


An aircraft manufacturer uses a fully IP-based communications solution from Rohde & Schwarz as a test system for verifying the radiocommunications of newly manufactured aircraft.

The main components of the Rohde & Schwarz solution are the R&S®VCS-4G system’s controller working positions and VoIP-capable radios (R&S®Series4200 for VHF and UHF; R&S®Series4100 for HF). All devices are interconnected via a simple IP infrastructure. Thanks to the fully IP system design, the entire solution can be installed in a compact footprint consisting of only a couple of devices. Additional radios can be added at any time. Since the R&S®VCS-4G follows the EUROCAE ED-137 standard, ED‑137 compliant radios from other manufacturers can also be integrated.

For the testing activities between the ground radio station and cockpit, the R&S®VCS-4G system provides all relevant air-ground communications services for VHF, UHF and HF frequencies.

System overview:

  • R&S®VCS-4G controller working positions
  • Rohde & Schwarz VoIP radios for VHF/UHF and HF

The test system was integrated by Rohde & Schwarz.