Industrial operations live and die by their field communications. When a pipeline pressure sensor stops reporting or a remote wellhead drops off the network, production slows, safety margins shrink, and money burns. For operators spread across hundreds of miles, a dependable radio network is vital.

SCADA doesn’t just send data. It moves two classes of traffic at once: critical control and everything else. 

Critical signals, like shutdown commands, high-pressure alarms, pump and valve actions can’t lag. Many utilities design around end-to-end delays on the order of 100 milliseconds for SCADA control traffic because anything slower can let equipment damage or safety events develop.

Bulk flows like trend logs, production reports, and maintenance records can tolerate delay. A solid network guarantees the first without starving the second.

Now add field reality: remote sites with no commercial power, brutal temperature swings from 140°F sun to hard freeze, salt spray, vibration, and the constant need to lock down remote access against attackers who explicitly target industrial control systems.

You don’t just have a networking problem. You have an operational risk problem. The rest of this guide walks through how to design radio and tower networks that still work when conditions are trying to break them.

Mixed Traffic, Mixed Urgency

SCADA networks carry messages with very different timing expectations. Emergency shutdowns and trip conditions sit in the “late equals damage” category. These signals need immediate delivery and guaranteed execution. Delays become a risk.

Then there’s slow data: historian tags, production totals, compliance snapshots. That information matters for reporting, optimization, and maintenance planning, but it doesn’t have to arrive this instant.

The trick is to enforce Quality of Service (QoS) so control traffic rides in a priority lane and never fights with bulk uploads or dashboard refreshes.

Bandwidth needs vary wildly. A single tank level transmitter might limp along at 9.6 kbps. Add high-frequency sensors, security video, and analytics, and you’re suddenly pushing megabits. Smart designers assume “extra” capacity will not stay extra. Growth always comes.

Environmental and Operational Stress

Remote compressor stations 80 miles from town don’t get fiber, and they’re not always inside reliable LTE footprints. Radio becomes the lifeline.

Power is scarce. If the nearest utility feed is 20 miles away, radios and RTUs run on solar and batteries. That power system has to ride out a week of cloudy weather without dropping critical visibility.

The environment tries to kill hardware. Cabinets cook in full sun, then freeze overnight. Salt air corrodes terminals. Pumps shake hardware loose. IP67-rated enclosures, conformal coating, gasketed connectors, and active temperature management aren’t “extras” — they’re what keep the link up.

Frequency Strategy: Licensed vs. Unlicensed

Choosing a spectrum is a risk decision. Licensed spectrum costs more, but under FCC Part 101, fixed microwave users get coordinated, exclusive channels for their service area.

That protection dramatically reduces interference and stabilizes high-capacity backbone links between key sites such as plants, compressor stations, and control centers.

Unlicensed bands, most commonly 900 MHz ISM (902–928 MHz) and 2.4 GHz, are attractive because hardware is cheap and no license application is required. 

Range at 900 MHz is excellent for wide oil, gas, and water systems, but those bands are crowded and channel choices are limited. Interference from other industrial users (and even consumer devices) can cause retries and dropped packets right when you need dependable control.

The safe pattern is to put backbone and high-risk assets on licensed or protected links, then use unlicensed where occasional retries are acceptable.

Path Analysis and Link Budgets

RF doesn’t care about project deadlines. Line of sight is more than “I can see the other tower.” You also have to clear the Fresnel zone; the three-dimensional RF “bubble” between antennas.

Standard practice is to keep at least 60% of the first Fresnel zone clear of trees, terrain, and structures so reflections don’t tear down link quality. Ignore that and you’ll watch reliability collapse during temperature swings or fog.

After geometry comes math. A link budget starts with transmitter power and antenna gain, subtracts feedline and path losses, and compares what’s left to receiver sensitivity.

The difference is a fade margin; your safety cushion against rain fade, ducting, fog, and general atmospheric weirdness. 

Long microwave hops are often engineered for roughly 20 dB of fade margin to hit “four nines” (≈99.99%) style availability. Anything below ~15 dB on a mission-critical path is asking for middle-of-the-night outages.

One last point: software models lie if the inputs are stale. Terrain changes. Trees grow. Metal structures appear. Always verify critical paths in the field (or by drone) before treating a model as gospel.

Tower Siting and Civil Work

Where you drop a tower drives coverage, cost, and survivability. Hilltops give elevation and cleaner shots but invite lightning and access headaches. Valleys are easier for maintenance crews but may force taller structures just to clear terrain.

Permitting rarely moves fast. Expect FCC coordination, FAA lighting/marking rules on taller structures, local zoning, environmental impact and cultural resource reviews, sometimes even endangered species surveys. Bake that time into the plan.

Foundations and grounding are not “check the box” items. Soil conditions decide foundation type. Seismic and ice loading matter in certain regions. Proper grounding and lightning protection guard both equipment and people. Cutting corners here gets expensive or dangerous.

Antennas, Alignment, and Diversity

Antenna choice quietly shapes network behavior. Omnidirectional antennas make sense for a hub talking to lots of remotes in all directions. Directional antennas throw a tight beam downrange and are ideal for long point-to-point shots, but only if they’re aligned and mounted so they stay aligned.

Diversity is cheap insurance. Space diversity (two receive antennas at different heights) and frequency diversity (sending the same data on two channels) both help ride through atmospheric fades that would wipe out a single antenna.

Yes, it costs more. So does downtime.

Install discipline matters. Polarization must match or you can lose 20 dB instantly. Every coax run needs real weatherproofing; water in a connector will kill an RF path faster than almost anything else. Mounts have to resist wind and vibration so they don’t slowly drift. Plan yearly inspections so you fix issues before they snowball.

Redundancy and Failover

Any single point of failure in SCADA comms will eventually fail. Good designs remove them. Critical sites should have a primary and a backup path, ideally via different towers, different frequency bands, or even different radio technologies. With automatic failover watching link health and switching in milliseconds.

Geographic diversity is your safety net when lightning, power loss, or weather takes out an entire hub. If a main tower dies, a secondary hub 50 miles away should already be syncing data and able to assume control. Dual infrastructure costs money, but compare it to shutting in production or losing pipeline visibility.

Continuous monitoring ties it together. Operations should see live signal strength, error rates, and throughput for each hop. Alarms should trigger upon degradation before users complain. Trend data helps you spot repeating weak points, like a microwave leg that always sags at sunrise.

Cybersecurity in the Field

Attackers actively go after SCADA and other industrial control systems, and U.S. agencies have warned about purpose-built malware that targets field devices, remote access paths, and engineering workstations. The response looks a lot like “defense in depth,” adapted for the field:

• Segment networks so a compromise in corporate IT can’t walk straight into safety systems or compressor controls.
• Control and log remote access instead of leaving standing always-on tunnels. Use strong authentication, preferably multi-factor.
• Encrypt radio traffic (for example with modern AES-class encryption) so intercepted data isn’t immediately useful.
• Assume hardware can be stolen. A missing field radio shouldn’t automatically have valid trust inside your network.

Survey, Plan, Prove

Paper designs meet dirt during site surveys. That “clean shot” on the drawing may clip a new utility line. The control shed might not have ventilation for radio gear. The access road may turn to mud every spring. Physical verification prevents expensive surprises.

Integration planning saves you from finger-pointing during startup. 

• Confirm radios speak the protocol your SCADA host expects.
• Check voltage and load against the site’s actual power budget.
• Bench-test full chains (radio → RTU/PLC → SCADA) before you send crews hundreds of miles to install.

Schedules need margin. Hardware lead times slip, weather windows close suddenly, and key people get pulled to emergencies. Build slack and line up alternates for radios, antennas, and power gear.

Test Like You Mean It

Commissioning is about performance, not just “does it turn on.” Run bit-error-rate tests to verify data integrity. Measure throughput. Log receive levels, fade margin, and error counts at different times of day and in different weather.

RF changes with temperature and humidity; capture that baseline now so you can compare six months later when someone claims “the link got worse.”

Training closes the loop. Control room staff need to read link-health dashboards at 2 AM without guessing. Field techs need torque specs, inspection intervals, and troubleshooting flowcharts. Give them short job aids, not just a binder on a shelf.

Preventive Maintenance

Most ugly outages trace back to skipped basics. 

Batteries lose capacity predictably; test quarterly and replace before failure. Thermal cycling loosens RF connectors; re-torque annually. Dust kills solar performance; clean panels. A consistent checklist beats heroics later.

Optimization and Growth

Use performance data to tune, not just repair. Underused links can absorb new sites without a forklift upgrade. 

Hops with a huge fade margin may safely run at lower power, extending gear life. Map expected expansion so you know where the next tower or repeater needs to go. Track bandwidth use so you can order capacity before congestion becomes downtime.

Also plan refresh cycles; keeping 20-year-old radios alive only works until the last spare part disappears.

Vendor and Technology Choices

Specs don’t tell the whole story. Raw transmit power and receiver sensitivity matter, but mean time between failures, spares availability, and support response matter more over the 10-year life you’re actually buying. The “cheap” radio becomes expensive fast if it dies monthly and nobody can service it.

When you compare costs, look at the total cost of ownership. Hardware might be 30% of the lifecycle. Add install labor, licensing (for protected spectrum), maintenance, truck rolls, downtime exposure, and power. Price the cost of going dark at 3 AM. That usually makes “premium” gear look pretty reasonable.

You’re not just buying boxes. You’re picking who answers the phone in a storm, who stocks spares, and who trains your crew.

Several trends are already reshaping field comms. Private 5G aims to give industrial users dedicated spectrum slices, predictable latency, and prioritized traffic — basically carrier-grade wireless without handing the keys to a public carrier.

Mesh networks keep getting smarter and lower-power, making self-healing topologies practical even in huge, rough geographies. And edge analytics is starting to watch link health and hardware conditions in real time, flagging problems before humans notice.

Designing a SCADA radio/tower network is not “put up an antenna and hope.” 

It’s engineering for latency, power limits, terrain, weather, interference, lightning, and people with bolt cutters.

It’s planning redundancy so one broken tower doesn’t blind your whole system.

It’s cybersecurity that assumes outsiders will try to get in. And it’s disciplined upkeep so the network you build on day one still works in year ten.

At PLC Construction, we build these systems with safety, uptime, and maintainability front and center. We combine what’s proven: proper spectrum planning, hard infrastructure, layered security with emerging tools that make the network smarter over time.

The payoff is simple: if you treat field communications like core infrastructure instead of afterthought wiring, the network will pay you back in reliability, safety, and flexibility for years.