Timing advance calculation and prach scheduling for haps switching

A method comprising:

• receiving, by a user equipment, a notification indicative of a switch from a first platform to a second platform;
• calculating, by the user equipment, a timing advance for use with the second platform;
• and
• accessing, by the user equipment, the second platform after the switch to the second platform, the accessing based on at least the calculated timing advance.

An apparatus comprising:

• at least one processor;
• and
• at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least:
• receive a notification indicative of a switch from a first platform to a second platform;
• calculate, a timing advance for use with the second platform;
• and
• access the second platform after the switch to the second platform, the access based on at least the calculated timing advance.

An apparatus comprising:

• at least one processor;
• and
• at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least:
• serve at least a user equipment;
• and
• broadcast a notification to the user equipment, the notification indicative of a switch from the apparatus to a second platform to enable the user equipment to access the second platform after the switch.