Published: June 2, 2026 by Roombanker Engineering Team
An Installer’s Problem in Athens
A security installer in Athens placed a door sensor 40 meters from the hub — well within the advertised “3500 meter open-air range” of the wireless alarm system. The sensor paired successfully. The system passed the walk test. He moved on to the next job.
Three days later the customer called. The sensor dropped offline, came back on its own, then dropped again two days later. Then again the following week. The hub was working. The sensor battery was at 98 percent. The distance had not changed.
The problem was not range. It was stability.
This article explains what signal stability actually means for wireless alarm systems, how it differs from range, and how to measure — and improve — it on real Mediterranean installations.
What Signal Stability Means in a Wireless Alarm Context
Every wireless alarm system has a range spec. Very few publish a stability spec. Stability is not one number. It is a combination of metrics that determine whether a sensor that paired successfully stays connected over months of real-world operation.
The relevant metrics are:
Packet delivery rate (PDR). When a sensor detects an event — door opens, PIR triggers — it transmits a data packet to the hub. The packet delivery rate is the percentage of those transmissions that arrive intact on the first attempt. A stable system maintains a PDR above 99 percent under normal conditions. Below 95 percent, the sensor is retransmitting frequently, which drains battery and creates gaps in coverage.
Supervision success rate. Most wireless alarm systems require sensors to check in periodically — typically every 15 to 30 minutes. The supervision success rate is the percentage of these check-ins that succeed without retry. A sensor missing three consecutive supervisions is declared offline. In a stable installation, the rate should be 100 percent over any 24-hour period.
RSSI consistency over time. Received Signal Strength Indicator (RSSI) measures the signal level between sensor and hub. A single RSSI reading at installation tells you the sensor is reachable. RSSI *variance* over time tells you whether the link is reliable. A sensor that shows RSSI of -75 dBm at installation but drifts to -95 dBm at 3 PM every afternoon has a stability problem, not a range problem.
Recovery from interference. No wireless link is perfect. What matters is whether the system recovers automatically when interference occurs — a garage door motor running, a passing truck on a nearby road. A stable system recovers within one supervision cycle without user intervention.
What Degrades Signal Stability
Stability problems rarely have one cause. They accumulate from multiple factors, each adding a few decibels of loss or a few milliseconds of delay.
Multi-path reflection. Radio signals bounce off steel beams, concrete walls, and metal door frames. The hub receives the direct signal plus reflected copies arriving at slightly different times. In buildings with large metal surfaces — warehouses with corrugated roofs, commercial kitchens with stainless steel equipment — reflected signals can cancel the direct signal at certain points. The sensor is physically close but the net signal at the receiver is weak.
Moving metal objects. Mediterranean residential and commercial buildings commonly feature steel security shutters, rolling garage doors, and metal awnings. When these move, they change the RF environment. A door sensor that works perfectly with the steel shutter raised may lose connection when the shutter is lowered, because the metal mass now sits directly in the signal path. This explains many “intermittent” faults that appear and disappear without explanation.
Weather. Temperature inversions, heavy rain, and high humidity all affect RF propagation. The effect is small per event — typically 3-6 dB — but enough to push a marginal link below the receiver threshold. In Mediterranean coastal areas, morning sea mist adds consistent attenuation that disappears by midday, creating a degradation pattern installers never see during a walk test.
Competing RF signals. In the 868 MHz band used by European wireless alarm systems, interference comes from GSM base stations, TETRA emergency services radios, and smart utility meters. In dense urban environments like central Istanbul or downtown Athens, the noise floor can be 10-15 dB higher than in suburban installations. A system stable in a suburban villa may produce supervision failures in a city-centre apartment due to ambient RF noise alone.
Building materials. This is the most common cause of stability problems in the Mediterranean region and deserves its own section below.
Range vs Stability: Why They Are Different Metrics
Open-air range is measured in a straight line, outdoors, with no obstacles, no interference, and optimal antenna orientation. It is a useful benchmark for comparing radio hardware performance under identical conditions. It is not a predictor of installed performance.
A system with 3500 metres of open-air range and one with 500 metres both need to function inside a building where the maximum sensor-to-hub distance is rarely more than 50 metres. Open-air range is irrelevant in that context. What matters is whether the link maintains adequate signal margin through three reinforced concrete floors and past a steel security door.
Range tells you the maximum distance. Stability tells you the minimum signal margin above the receiver threshold. A system with 20 dB of link margin is stable. A system with 3 dB of link margin may pair but will fail when conditions change.
Spec sheet numbers do not tell you this. Measured field data does.
How to Measure Signal Stability on Site
You do not need expensive equipment. A wireless alarm system with diagnostic tools — such as those in the Roombanker RBF Protocol accessible through the installer app — provides everything.
Step 1: Measure RSSI variance over 24 hours. Record RSSI at installation time, then check it at different times — early morning, mid-afternoon, evening when metal shutters are lowered. A variance of more than 10 dB between readings indicates a stability risk.
Step 2: Review supervision failure count. After 48 hours, check the supervision log. Any failure above zero warrants investigation. Three or more failures in a week means sensor placement needs adjustment or a repeater is required.
Step 3: Measure packet loss rate. If the system logs retransmissions, review retry counts per sensor. A sensor that retransmits more than 2 percent of event packets is operating near the reliability margin, even if it never drops supervision.
These measurements turn “it feels stable” into “it is stable.” When a customer questions the system, show them the supervision log.
Interested in deploying Roombanker’s RBF Protocol for your installation business? Contact our team to learn more. Not the spec sheet.
RBF Protocol’s Stability Features
Roombanker’s RBF Protocol was designed from the ground up for in-building reliability, not open-air records. Its stability features address the specific failure modes described above.
Narrowband modulation. RBF uses narrowband modulation at 868 MHz, concentrating transmission power in a narrower frequency channel than wideband alternatives. The practical effect is a higher signal-to-noise ratio at the receiver for the same transmission power. In RF-noisy environments — urban apartment blocks, commercial districts, industrial zones — this means the signal stands out above the noise floor rather than competing with it.
Adaptive data rate. RBF adjusts its data rate based on link quality. When the link is clean, data transmits at higher speed. When the link degrades, the protocol automatically drops to a lower data rate, improving receiver sensitivity by up to 6 dB. The transition happens per packet without user intervention.
Frequency agility. RBF can switch operating channels within the 868 MHz band when it detects persistent interference on the current channel. This matters in urban Mediterranean environments where intermittent interference — taxis with two-way radios passing by, nearby utility meter networks polling — can occupy a channel for seconds or minutes. Instead of waiting for interference to clear, the protocol moves to a clear channel and continues communicating.
These features do not appear on a spec sheet’s range line. They appear in the supervision log as zero failures over months of operation.
Mediterranean Building Factors: Why This Matters Here
The Mediterranean construction mix is uniquely challenging for wireless signal stability. Three factors dominate.
Concrete plus rebar equals a partial Faraday cage. The steel rebar inside reinforced concrete creates a conductive mesh that attenuates RF signals. At 868 MHz, a single 20-centimetre reinforced concrete floor causes approximately 25-35 dB of attenuation. Multiple floors multiply the effect. A sensor in a basement garage communicating with a hub on the fourth floor is not fighting distance. It is fighting three reinforced concrete slabs.
Stone walls produce variable attenuation. Not all stone is the same. A 40-centimetre solid limestone wall attenuates differently from a 60-centimetre rubble-filled cavity wall. In older Mediterranean buildings — Greek island stone houses, Turkish village homes, Italian farmhouses — wall construction varies within the same building. A sensor that works mounted on one stone wall may fail on another wall of the same room, because the internal composition of the wall is different.
Steel shutters create intermittent blocking. Rolling steel security shutters are standard across Mediterranean residential construction, particularly on ground-floor windows and terrace doors. When lowered, they place a continuous metal sheet between the sensor and the hub. A door sensor mounted on a frame with a steel shutter above it may test fine during the day with shutters open but fail supervision after dark when shutters are closed. This is one of the most commonly missed stability issues because installers work during daylight hours.
Related: 4 Wireless Alarm Installation Mistakes That Cost You Callbacks
What to Tell Your Customer
When a customer asks about range, they are usually asking about something else: “Will this system work reliably in my building?” A 3500-metre open-air range number does not answer that question. A supervision log with zero failures over 90 days does.
Here is how to reframe the conversation on site:
“For market-specific wireless performance data across Central and Eastern Europe, see our Poland Wireless Security Market Report 2026.
When a customer asks about range, tell them about stability.
Related Articles:
• How Wireless Alarm Communication Works — Understanding what happens between sensor trigger and hub receipt
• RF Jamming Detection Explained — How modern systems resist deliberate signal interference
• How Security Distributors Make Money — Turning technical advantages into distributor value
• Hardware Margin vs Recurring Revenue — Which revenue model builds lasting wealth
• Poland Wireless Security Market Report 2026 — Central European market data
• Contact Roombanker — Learn about distributor and installer partnerships
When they ask about stability, show them the supervision log.
Interested in deploying Roombanker’s RBF Protocol for your installation business? Contact our team to learn more.”
The supervision log records every check-in from every sensor, every retransmission, every channel change. It is the only true measure of whether a wireless alarm system is performing as designed in a specific building.
If the spec sheet is all a manufacturer offers for proof of reliability, ask what happens when the steel shutters come down. Ask how many decibels of link margin the system has after two concrete floors. Ask how the protocol recovers from interference.
The answers to those questions determine whether your installation generates maintenance calls for years — or runs silently, sensor after sensor, month after month, without your phone ringing.
Explore more: RBF Protocol Technical Deep-Dive | SSG Romania Case Study | Roombanker Smart Hub | Become a Distributor