A container terminal at peak operation is one of the most hostile cellular environments in commercial logistics. Most operators are tracking their vehicles on it anyway.

The default tracking architecture inside the fence line is the same architecture sold to a long-haul trucking fleet: a cellular modem in every asset, GPS pinging a public carrier network, positions landing in a SaaS dashboard somewhere in the cloud. It works well enough on the highway. It was never designed for the apron.

This is not a story about a missing feature in a fleet platform. It is a story about an industry that picked a communication layer by inheritance and never went back to audit the decision.

The Default That Nobody Audited

Cellular GPS became standard in marine terminal vehicle tracking because it was already standard everywhere else. Drayage fleets had it. Yard management systems integrated with it. Off-the-shelf telematics modules supported it out of the box. When a terminal decided to start tracking its UTRs, hostlers, or top-handlers, the path of least resistance was to install the same hardware the trucking world was already using and route it through a public carrier.

What almost never happened was the prior step: an actual RF coverage survey of the operating area, under load, at the times of day when tracking would matter most.

The system went live. The dashboard lit up. The assumption — that the dots on the screen reflected reality, in real time, everywhere on the terminal — was never tested.

What Stacked Containers Do to Cellular

A working container yard is, in radio-frequency terms, a forest of metal. Loaded TEUs are corrugated steel boxes stacked four to six high across acres of apron. Ship-to-shore cranes are several thousand tons of structural steel sitting between the apron and the open sky. Reefer racks add active electrical noise. Rubber-tired gantries roll metal canyons up and down the aisles.

Steel attenuates RF. That is not a controversial claim — it is the same reason a cellphone signal drops inside an elevator. The International Telecommunication Union's propagation guidance for indoor and obstructed environments documents penetration losses through metallic structures in the tens of decibels, depending on frequency and geometry. [1] In an aisle bounded on both sides by stacked containers, a cellular signal arriving at a yard tractor's modem has typically passed through, reflected off, or diffracted around significant metal — and the resulting signal-to-noise picture changes minute by minute as containers are restacked.

That is the static problem. The dynamic problem is worse.

Public cellular networks are shared. When a gate rush coincides with a vessel call and a few thousand drayage drivers, longshore workers, and visitors are all pulling video, voice, and data through the same macro cells, the network does what it is designed to do: it prioritizes. The 3GPP standards that govern LTE and 5G define quality-of-service classes that explicitly rank voice and conversational traffic ahead of best-effort data. [2] Telematics pings sit in the best-effort tier. When the cell is loaded, those pings are the first thing to be delayed, queued, or dropped.

A telematics platform reports "current location." What it is actually reporting is "the most recent location that successfully made it through the network." Those are not the same answer.

Why Latency Is a Safety Conversation, Not a UX Conversation

Latency in a consumer app is a user-experience problem. The map redraws a beat slow; the ETA shudders; the user mutters and moves on. Nobody is hurt.

Latency in a marine terminal tracking system is not that.

According to the National Institute for Occupational Safety and Health, fatal injuries among marine terminal and port workers from 2011 through 2017 occurred at an annual rate of 15.9 per 100,000 workers — "a rate five times that of the U.S. workforce overall." [3] The U.S. Bureau of Labor Statistics measured the all-industry fatal injury rate at 3.3 per 100,000 full-time equivalent workers in 2024. [4]

The mechanism of those fatalities is not exotic. A yard tractor and a stevedore on foot converge in the same aisle. A top-handler swings into a lane a worker just stepped into. Two pieces of equipment intersect at a blind corner during a vessel discharge.

In each case, the safety value of a tracking system is determined by one question: when those two assets are three seconds from contact, does the system know where they are now, or does it know where they were the last time the carrier network let a packet through?

"Where the yard truck was 300 milliseconds ago" is an acceptable answer for fleet utilization reporting. It is not an acceptable answer for collision avoidance. And the carrier network has no idea which one you are asking it for.

Private Radio in the Marine Terminal Context

There is a different category of system. It is the same category of system the airfield industry has been quietly moving toward for the same reasons.

A private wireless network — whether an ISM-band radio system, a private LTE on the FCC's Citizens Broadband Radio Service spectrum, or a licensed industrial band [5] — is built and operated by the terminal, for the terminal. Coverage is engineered to the actual geometry of the yard, with small cells or access points positioned to fill the dead zones that a public macro tower can never reach. Latency is deterministic, because the only traffic on the network is the traffic the terminal puts on it. And the data does not leave the fence line unless the terminal chooses to send it.

The trade-offs are honest ones. Private wireless requires capital, spectrum coordination, and an integrator who has stood up a yard before. It is a real infrastructure decision, not a SaaS subscription. Several major U.S. and European container ports have made it anyway. The Port of Hamburg's HHLA terminals partnered with Deutsche Telekom on a dedicated 5G campus network specifically to handle the latency and reliability profile that public cellular could not. [6] Cisco and the Port of Los Angeles built a private wireless deployment for similar reasons. [7]

The deployments are not identical. The thesis behind all of them is.

What to Evaluate Before Specifying

If your terminal is currently tracked over cellular and the system was never measured against the actual operating environment, three questions are worth asking before you renew the contract.

• Peak-load latency. Not headline latency on a quiet Sunday morning. Latency measured at the gate rush, during a vessel call, when the carrier network is at its busiest. If your provider cannot produce that number, the system is not specified — it is assumed.
• Coverage in the worst RF spots. Not coverage at the administrative building. Coverage in the apron alongside an active vessel, in the RTG aisles between stacked rows, in the breakbulk warehouses, at the gate when the queue backs up. A heat map produced at the worst hour of the worst week is the only one that matters.
• Data sovereignty. Where does the position data go, who owns it, and what regulatory exposure does that create? For an MTSA-regulated facility, "in our vendor's cloud" is a different posture than "inside the fence line." Both are valid choices. Only one of them is a choice that has been made deliberately.

The Boundary of the Argument

This essay is not anti-cellular. Cellular is the right answer for off-terminal tracking — drayage routing, gate-out visibility, intermodal handoff, last-mile delivery. The moment a tracked asset crosses the fence line outbound, the public carrier network is the correct medium. It is wide-area, low-cost, and well-understood.

The argument is bounded to what happens inside the fence line of a working marine terminal. That is the environment where the assumption breaks. That is the environment where the communication layer becomes a safety decision, not a procurement decision.

Final Thought

Most terminals running cellular tracking today are not running a bad system. They are running a system that was specified for one environment and deployed into another. The dashboard works. The dots move. The reports export. None of that is the same as a real-time picture of the yard at the moment a real-time picture is needed.

For tracking inside the fence line of a working marine terminal, the communication architecture is the decision.

Sources

[1] International Telecommunication Union, Radiocommunication Sector. Recommendation ITU-R P.2040: Effects of building materials and structures on radiowave propagation above about 100 MHz. https://www.itu.int/rec/R-REC-P.2040

[2] 3GPP TS 23.203, Policy and charging control architecture (defines standardized QoS Class Identifiers for LTE/5G traffic prioritization). https://www.3gpp.org/dynareport/23203.htm

[3] Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (NIOSH). Marine Terminals and Port Operations. https://www.cdc.gov/niosh/maritime/about/marine-terminals-and-port-operations.html

[4] U.S. Bureau of Labor Statistics. National Census of Fatal Occupational Injuries in 2024 (released February 19, 2026). https://www.bls.gov/news.release/cfoi.nr0.htm

[5] U.S. Federal Communications Commission. 3.5 GHz Band Overview (Citizens Broadband Radio Service). https://www.fcc.gov/35-ghz-band-overview

[6] Hamburger Hafen und Logistik AG (HHLA) and Deutsche Telekom. 5G MoNArch — 5G Mobile Network Architecture for diverse services, use cases, and applications in 5G PPP. Port of Hamburg 5G testbed program. https://www.hhla.de/en/press/press-releases/press-release-detail/successful-final-presentation-of-the-5g-monarch-project-at-the-port-of-hamburg

[7] Cisco Systems. Port of Los Angeles — Connected Port Operations. Cisco customer story documenting private wireless and IoT infrastructure deployed across terminal operations. https://www.cisco.com/c/en/us/about/case-studies-customer-success-stories/port-of-los-angeles.html