An integrated access and backhaul network is provided with network nodes that can establish timing synchronization with any other network nodes. In an embodiment, network nodes in a multi-hop integrated access and backhaul network have a hop order of n, wherein n represents a number of hops from a node connected to the core network via a wired connection. In an embodiment, instead of using the network node with a hop order of 0 as the timing synchronization reference for over-the-air synchronization, any network node can use any other network node as a synchronization reference. A relay node can first establish a wireless link to said arbitrary node. Said wireless link is then used to synchronize the relay or IAB node using a Precision Time Protocol (PTP) implementation.