Adaptation layer setup and configuration in integrated access backhauled networks

A method, in a central unit of a donor base station comprising the central unit and one or more distributed units, the method comprising:

• using radio resource control (RRC) signaling to establish a connection with a mobile terminal (MT) part of a relay node, via a distributed unit of the donor base station;
• after establishing the connection, signaling with the MT part of the relay node to configure an adaptation layer in a protocol stack for the MT part of the relay node, the adaptation layer providing for routing of incoming packets to one or more further relay nodes or to one or more user equipments (UEs) connected to the relay node and for mapping of those incoming packets to bearers;
• and
• configuring an adaptation layer at the distributed unit of the donor base station, the adaptation layer at the distributed unit of the donor base station being configured to route incoming packets to a proper relay node of one or more relay nodes downstream of the donor base station.

A relay node, comprising:

• first radio circuitry configured to communicate with the donor base station or another relay node between the relay node and the donor base station;
• second radio circuitry configured to communicate with one or more user equipments (UEs) or one or more other relay nodes, or both;
• and
• processing circuitry operatively coupled to the first and second radio circuitry and configured to:
• connect to the donor base station;
• after establishing the connection, configure an adaptation layer in a protocol stack for an MT part of the relay node, the adaptation layer providing for routing of incoming packets to one or more further relay nodes or to one or more UEs connected to the relay node, via a distributed unit part of the relay node, and for mapping of those incoming packets to bearers;
• and
• after configuring the adaptation layer for the MT part of the relay node, configure an adaptation layer for the distributed unit part of the relay node for forwarding packets exchanged between a central unit of the donor base station and a first further relay node downstream of the relay node.

An apparatus configured for operation as a central unit of a donor base station, the apparatus comprising:

• communication circuitry configured to communicate with the one or more distributed units;
• and
• processing circuitry operatively coupled to the communication circuitry and configured to configure an adaptation layer in a relay node by:
• using radio resource control (RRC) signaling to establish a connection with a mobile terminal (MT) part of a relay node, via the distributed unit of the donor base station;
• after establishing the connection, signaling with an MT part of the relay node to configure an adaptation layer in a protocol stack for the MT part of the relay node, the adaptation layer providing for routing of incoming packets to one or more further relay nodes or to one or more user equipments (UEs) connected to the relay node and for mapping of those incoming packets to bearers;
• and
• configuring an adaptation layer at the distributed unit of the donor base station, the adaptation layer at the distributed unit of the donor base station being configured to route incoming packets to a proper relay node of one or more relay nodes downstream of the donor base station.