Backhaul

Backhaul is the portion of a telecommunications network that transports aggregated traffic from the edge toward the core. It links access networks serving homes, businesses, and wireless users to central switching and routing infrastructure, enabling services such as voice, video, and data to reach the internet and other networks. Backhaul lies between the access network and the core and is distinct from local access.

Backhaul can be wired or wireless. Wired options include fiber optic links using DWDM and Ethernet transport with IP/MPLS; copper and coax serve legacy, shorter-haul deployments. Wireless backhaul uses microwave or millimeter-wave links to connect sites where fiber is unavailable; satellite backhaul serves remote locations but with higher latency and cost. Redundant paths are common for reliability.

In mobile networks, backhaul carries user data and signaling from base stations to the core. As networks grow in speed and density, backhaul must provide greater capacity and lower latency. Fronthaul and midhaul are related terms describing transport within the radio access network; backhaul generally covers links toward the core.

Key design considerations include capacity planning, latency, scalability, reliability, QoS, and security. Spectrum management, weather impacts on wireless links, and regulatory requirements can affect performance. Redundant routes and diverse paths help ensure service continuity.

Standards and management practices come from ITU-T, IEEE, and ETSI. Ethernet OAM, MPLS-TP, and SDH/OTN transport are commonly used, with network management systems monitoring performance and provisioning traffic flows.