Backhaul is the transport network that carries traffic from radio sites, such as cell towers or small cells, into the wider carrier network and core systems. It may use fiber, microwave, or other fixed links. In mobile networks, the radio link serves the user locally, while backhaul moves voice, data, and control traffic to the places where it can be routed, authenticated, and managed.
Backhaul matters in cyber security because it is a critical bridge between edge infrastructure and central systems. If an attacker can disrupt or tamper with it, they may cause outages, degrade service, intercept unprotected traffic, or reroute communications through compromised equipment. Real-world risks include physical cable cuts, unauthorized access to transport routers, weak configuration on microwave links, and denial-of-service attacks against supporting network devices. Defenders protect backhaul with encryption, segmentation, access control, redundant paths, and continuous monitoring to keep the network available and harder to compromise.