• What does VDES stand for?

VHF Data Exchange System (VDES)

  • What is VDES?

VHF Data Exchange System (VDES) is a radio communication system that operates between ships, shore stations and satellites on Automatic Identification System (AIS), Application Specific Messages (ASM) and VHF Data Exchange (VDE) frequencies in the Marine Mobile VHF band

  • What is the difference between VDES and AIS?

AIS is a component of VHF Data Exchange System (VDES) which operates using the Gaussian Minimum Shift Keying (GMSK) modulation scheme, other components of VDES will use higher capacity modulation schemes.

  • Why VDES?

The VHF Data Exchange System (VDES) is seen as an effective and efficient use of radio spectrum, building on the capabilities of AIS and addressing the increasing requirements for data through the system.  New techniques providing higher data rates than those used for AIS is a core element of VDES.  Furthermore, VDES network protocol is optimized for data communication so that each VDES message is transmitted with a high confidence of reception. VDES supports e-Navigation and provides access to the Maritime Cloud.

  • What frequencies does VDES use?

VHF Data Exchange System (VDES) comprises a suite of channels in the Maritime mobile VHF band, which are detailed in the IALA VDES Guideline on the IALA website [http://www.iala-aism.org/product-category/publications/guidelines/] (Ref. Guideline number / section)

  • What is the roadmap for VDES?

VHF Data Exchange System (VDES) will continue to be developed over the next few years in accordance with the roadmap published in the VDES Guideline.


(Ref. Guideline number / section)

  • Are there any VDES test beds?

There are several VHF Data Exchange System (VDES) test beds detailed on the IALA website [http://www.iala-aism.org/products-projects/e-navigation/test-bedsprojects/]. Some of these test beds are currently active and others have now completed and the results are published under the test bed name on the website.

  • Where can I find more information on VDES?

Further information on VHF Data Exchange System (VDES) can be found in the IALA Guideline on VDES which is located on the IALA website [http://www.iala-aism.org/product-category/publications/guidelines/]

If you have a question that is not answered here, please send it to contact@iala-aism.org for consideration by the ENAV committee. Thank you.