Method for lossless upstream packet processing during movement between donors in backhaul and access hole combination system, and method for processing ip address during separation of cp and up

A method performed by an integrated access and backhaul (IAB) node in a communication system, the method comprising:

• obtaining, from a central unit (CU) of a target IAB donor, first information on a backhaul adaptation protocol (BAP) header rewriting, wherein the first information including information on a mapping between an old routing identifier (ID) associated with a first topology of a source IAB donor and a new routing ID associated with a second topology of the target IAB donor;
• in case that a BAP packet to be considered for the BAP header rewriting is identified, rewriting a first routing ID of the first topology included in a header of the BAP packet to a second routing ID of the second topology corresponding to the first routing ID based on the first information;
• and
• routing the BAP packet with the rewritten header, through a target path identified based on the second routing ID.

An integrated access and backhaul (IAB) node in a communication system, the IAB node comprising:

• a transceiver;
• and
• a controller configured to:
• obtain, from a central unit (CU) of a target IAB donor, first information on a backhaul adaptation protocol (BAP) header rewriting, wherein the first information including information on a mapping between an old routing identifier (ID) associated with a first topology of a source IAB donor and a new routing ID associated with a second topology of the target IAB donor,
• in case that a BAP packet to be considered for the BAP header rewriting is identified, rewrite a first routing ID of the first topology included in a header of the BAP packet to a second routing ID of the second topology corresponding to the first routing ID based on the first information, and
• route the BAP packet with the rewritten header, through a target path identified based on the second routing ID.