Methods and systems for routing data through IAB nodes 201, 202 in 5G communication networks. Embodiments herein allow routing data between a UE 206 and an IAB donor 200 though IAB nodes 201, 202 using adaptation layers of the IAB donor 200 and the IAB nodes 201, 202. The adaptation layers of the IAB donor 200 and the IAB nodes 201, 202 are configured by defining adaptation layer header and functionality. Mapping is performed between bearers/RLC channels of the UE 206 and the IAB node 202 and between bearers/RLC channels of the IAB nodes 201, 202 and the IAB donor 200. The means to perform the mapping is specified by the adaptation layers of either the IAB donor 200 or the IAB nodes 201, 202. The data is routed through the bearers/RLC channels. The embodiments include managing RLC layer functionality using either hop-by-hop ARQ or end-to-end ARQ.