Rach procedures for non-terrestrial networks

A system comprising:

• a user equipment (UE), the UE comprising:
• a radio;
• and
• a processing circuit,
• the processing circuit being configured to:
• calculate a timing advance based on:
• location information of the UE;
• and
• an ephemeris of a non-terrestrial network node;
• randomly select a random value from a plurality of values;
• and
• send, at a transmission time, by the UE, to the non-terrestrial network node, a random access (RA) message,
• the RA message including a signature,
• wherein:
• the transmission time differs from a nominal transmission time by an amount based on the random value, the nominal transmission time being based on the timing advance, or
• the signature differs from a nominal signature by a cyclic shift based on the random value.

A system comprising:

• a user equipment (UE), the UE comprising:
• a radio;
• and
• means for processing,
• the means for processing being configured to:
• calculate a timing advance based on:
• location information of the UE;
• and
• an ephemeris of a non-terrestrial network node;
• randomly select a random value from a plurality of values;
• and
• send, at a transmission time, by the UE, to the non-terrestrial network node, a random access (RA) message,
• the RA message including a signature,
• wherein:
• the transmission time differs from a nominal transmission time by an amount based on the random value, the nominal transmission time being based on the timing advance, or
• the signature differs from a nominal signature by a cyclic shift based on the random value.