Private 5G on CBRS for a port terminal: remote cranes, yard tractors and scanners on one radio network

A container terminal on the Gulf Coast covers about 250 acres with six berths. Its Wi-Fi mesh dropped connections as vehicles and container stacks moved, handheld scanners lost sessions when workers crossed between berths, and the operator wanted to run cranes remotely and add automated yard tractors. Steel stacks shadow radio signals, and a public carrier network is not designed for a yard. The terminal wanted a network it owned, could tune and could join to its terminal operating system.

We began with a radio survey and a propagation model that included stack heights, then placed 12 outdoor radios on towers and crane legs. They are Category B CBRS devices, which the rules in 47 CFR Part 96 permit to operate outdoors at higher power than Category A devices. CBRS uses 3.55 to 3.7 GHz, managed by a Spectrum Access System (SAS): each radio asks the SAS for channels, and the SAS grants them and can take them back. The base plan used General Authorized Access, which needs no license, and we checked whether a Priority Access License in the county would give protected channels for the most critical traffic.

A port is a coastal site, and coastal zones can be protected for federal radar. A SAS may limit or move channels near the coast, so the design assumes it will happen. We planned spare channel capacity, a fallback allocation of 20 MHz carriers and the way each radio would behave when it loses a grant, and we told the operator in plain words which parts of the yard have less margin. This is the kind of constraint that surprises owners who plan on a map instead of on a grant.

The core is a private 5G core with local breakout, so user traffic never leaves the terminal, and a second core at a backup site takes over if the first fails. Devices authenticate with SIMs and eSIMs the terminal controls. The air interface runs TDD in band n48 with an uplink-heavy frame pattern, because crane and tractor cameras send more than they receive. Quality-of-service classes protect crane control and vehicle telemetry ahead of scanner and office traffic. A firewall and 802.1X on the wired side keep the radio network, the terminal operating system and the corporate network apart.

Failure testing took as long as installation. We cut radios, backhaul links and a core, and measured what a tractor experienced while it crossed the yard from one radio to the next. The pilot on one berth ran for weeks before the rest of the terminal moved over, berth by berth, with the Wi-Fi mesh kept as a fallback until each berth was stable. Coverage and latency figures in this illustrative case are modeled for a design of this kind. Our article on private 5G versus Wi-Fi 6E and 7 explains the trade-offs.