The objective of the activity is to test the performance of beyond line-of-sight narrow-band communication links between ground andLEO satellites in operational conditions. One of the key aspects of the experiment is the effect of ionospheric refraction and reflection as an enabler of satellite links beyond the line of sight. The activity will include the development of a small payload and aground terminal. Targeted Improvements:Enabling new satcom use cases (e.g. low latency narrowband services including infrastructuremonitoring and control, coastal services, messaging or satellite TTC). Description: Signals at shortwave frequencies and below are not exploited for satellite communication because shortwave signals interact with the ionosphere. Depending on the local conditions the atmospheric layer between 60 and 1000km refracts or reflects signals creating a phenomenon known as skywave. With increasingfrequency this phenomenon diminishes until the wavefront's direction remains unaffected and the communication is line of sight. This activity will explore beyond line of sight satellite links utilising skywaves. Skywaves have the potential to significantly extend the range of LEO communication systems and could enable new satcom narrow-band use cases and applications such as gas or waterways monitoring and control, coastal services, stock exchange messaging or satellite TTC. However, today there is insufficient understanding of how the ionospheric impairments affect satellite links when skywaves are used. Hence, this activity will design and carry out a communication experiment in the 30.005- 30.01MHz band to characterize the performance of satellite links using skywaves in realisticconditions. The activity will develop a simple NGSO payload and a ground terminal. Measurement campaigns will be carried out todetermine the range of the beyond-line-of-sight communication to and from the satellite. The payload will consist of a receiver anda transmitter. Processing of the signals will be carried out on ground. Procurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to EMITS news "Industrial Policy measures for non-primes, SMEs andRD entities in ESA programmes". Footnote: On Delegation Request activities will only be initiated on the explicit request of at least one National Delegation.