When it comes to communication in alarm systems, there are two fundamentally different approaches: Wi-Fi-based systems that use the existing home network, and systems with a dedicated wireless protocol. Protexium consistently favours the second approach – and in this article we explain on a sound technical basis why this choice makes the difference between a security system and a toy.
The problem with Wi-Fi-based alarm systems
Wi-Fi (2.4 GHz or 5 GHz) is designed for everyday data transfer: streaming, video conferencing, smart TV. It was, however, never designed for safety-critical applications. The weaknesses in the context of home security are serious:
Overcrowded frequency band
The 2.4 GHz band, on which most inexpensive security cameras and sensors operate, is hopelessly overloaded. In the average residential area, dozens of Wi-Fi routers, Bluetooth devices, microwave ovens, baby monitors and smart home devices compete for the same frequencies. The result: packet loss, latency and unreliable connections – all factors that are unacceptable in a security system.
Limited range
The realistic range of a Wi-Fi signal in a residential environment is 30 to 50 metres – under optimal conditions. Reinforced concrete walls, underfloor heating and sources of interference often reduce the range to below 15 metres. Outdoor sensors in the garden or at the property boundary can hardly be reached reliably via Wi-Fi.
Easy to disrupt
A Wi-Fi jammer is available online for a few euros. Professional burglars use such devices to switch off Wi-Fi-based cameras and sensors before a break-in. The system often notices nothing – the sensors simply drop out silently.
High power consumption
Wi-Fi communication is power-hungry. Battery-powered Wi-Fi sensors typically last only a few weeks to months before the batteries have to be changed. This considerably increases maintenance effort and creates security gaps: a sensor with a flat battery is a sensor that offers no protection.
Dependence on the router
If the Wi-Fi router fails – whether through a power cut, a provider issue or deliberate sabotage – the entire security system collapses. An alarm system that depends on the internet connection is essentially not an alarm system at all.
Jeweller – the dedicated security wireless protocol
Protexium security systems are based on the Jeweller wireless protocol, developed by Ajax Systems specifically for professional security technology. Jeweller operates on the 868 MHz frequency band (sub-GHz) – a dedicated band reserved in Europe for short-range wireless applications under the EN 300 220 standard.
Unlike the overcrowded 2.4 GHz band, the 868 MHz band is virtually free of interference. It is not used by conventional consumer devices – no routers, no microwaves, no Bluetooth headphones transmit on this frequency. As a result, the security system enjoys an exclusive, interference-free communication channel.
Range: 2,000 metres vs. 30–50 metres
One of the most impressive advantages of the Jeweller protocol is its range. While Wi-Fi sensors cover a maximum of 50 metres in open space and shrink to 15–30 metres inside buildings, Jeweller reaches up to 2,000 metres outdoors. Inside buildings it is typically 100 to 200 metres – enough even for multi-storey villas, large commercial premises and extensive grounds.
This enormous range is due to the lower frequency: the lower the frequency, the better the penetration of walls, ceilings and other obstacles. The 868 MHz signal passes through several concrete walls without difficulty, whereas a 2.4 GHz Wi-Fi signal loses considerable strength at every wall.
For particularly large properties – such as industrial sites or expansive estates – the system offers so-called ReX range extenders that double the wireless range further without compromising security. Find out more about deployment in large properties on our High security page.
Battery life: up to 7 years vs. a few weeks
The extreme energy efficiency of the Jeweller protocol is another decisive advantage. Sensors such as the Ajax MotionProtect (motion detector) or the Ajax DoorProtect (door/window contact) achieve battery life of up to 7 years on a single battery. That means: you install the sensor and do not need to worry about changing the battery for years.
By comparison, battery-powered Wi-Fi cameras and sensors typically last only 2 to 8 weeks – a fraction of the Jeweller lifetime. The reason lies in the physics: Wi-Fi communication requires considerably more transmit power and more frequent data transmissions. The Jeweller protocol, by contrast, uses extremely short, energy-saving data packets that last only milliseconds.
The system automatically monitors the battery status of each sensor and warns you in good time – months in advance – when a battery change is due. At no point is there a risk that a sensor will fail unnoticed.
TDMA communication – precise time slots
Jeweller uses the TDMA method (Time Division Multiple Access). Each device in the system receives an exactly assigned time slot in which it communicates. This method offers several advantages over the chaotic Wi-Fi communication:
- No collisions: As each device has its own time slot, no data packets can collide – even with 200+ devices in the system.
- Guaranteed latency: Alarm signals reach the control panel within 0.01 seconds – regardless of network load.
- Ping monitoring: The control panel checks at regular intervals (12 to 300 seconds, configurable) whether each sensor is still reachable. If a device fails or is tampered with, this is detected immediately.
- Scalability: The system supports up to 200 devices per hub – without performance loss.
With Wi-Fi, by contrast, all devices use the same channel on a "first to transmit wins" basis (CSMA/CA). With many simultaneously active devices this inevitably leads to delays and packet loss – problems that are absolutely unacceptable in a security system.
AES encryption with dynamic keys
Every single communication in the Jeweller network is encrypted with AES (Advanced Encryption Standard). The encryption keys are generated dynamically – meaning that the key changes with every communication session. Even if an attacker could intercept and decrypt a single data packet (which is already practically impossible), that key would already be obsolete by the next transmission.
For comparison: many inexpensive Wi-Fi security cameras transmit their video data unencrypted or with the outdated WEP standard. Even when WPA2/WPA3 is used, encryption is only as strong as the Wi-Fi password – and default passwords are rarely changed. The Jeweller protocol, on the other hand, does not permit manual access to keys; they are negotiated cryptographically exclusively between hub and sensor.
You can read more about encryption standards and data protection architecture in our other articles on security technology.
Frequency hopping – 17 frequencies in 4 bands
The Jeweller protocol uses not a single frequency but dynamically hops between 17 different frequencies in 4 frequency bands. This frequency hopping method (Frequency Hopping Spread Spectrum, FHSS) makes the system extremely resilient to interference and eavesdropping attempts.
Even if an attacker were to block a single frequency, the system automatically switches to one of the remaining 16 frequencies. To block the system completely, an attacker would have to jam all 17 frequencies in all 4 bands simultaneously – a scenario that is practically impossible and would also be detected immediately by the anti-jamming system.
Frequency hopping happens fully automatically and transparently: neither the user nor the installer needs to configure anything. The system selects, in real time, the optimal frequency with the best signal-to-noise ratio.
Anti-jamming – detecting jammers immediately
While Wi-Fi-based systems fail silently in a jamming attack, the Jeweller system reacts actively and immediately. The control panel continuously monitors the noise level on all frequencies. If unusual interference is detected, the following happens:
- Immediate detection: Within seconds, the system identifies the jamming attempt.
- Alarm: The owner and the 24/7 monitoring centre are informed immediately of a jamming attempt – a jamming alarm is as critical an event as an intrusion alarm.
- Automatic frequency change: The system automatically switches to an unaffected frequency and continues communication without interruption.
- Alarm log: The jamming attempt is logged with a timestamp and can later serve as evidence.
For professional burglars, a jamming attack on a Jeweller system is therefore counterproductive: instead of disabling the system they trigger an alarm and draw attention to themselves. For information on our certified security standards, visit our Certifications & standards page.
Anti-spoofing – device authentication per session
In addition to anti-jamming, Jeweller also offers comprehensive anti-spoofing protection. Spoofing refers to the attempt to masquerade as a legitimate device and send false signals to the control panel – for example an "all clear" signal while a break-in is actually taking place.
In the Jeweller protocol, every device must re-authenticate in every communication session. Unique device identifiers, dynamic keys and cryptographic checksums are used. A counterfeit device that does not have the correct key is detected immediately and reported.
This is a fundamental security difference: Wi-Fi-based systems are susceptible to replay attacks and spoofing because they rely on standardised protocols whose vulnerabilities are well documented. Jeweller, by contrast, is a proprietary protocol with multi-stage authentication and offers no known attack vectors.
4 communication channels at the hub
While Wi-Fi-based alarm systems have only a single communication channel (Wi-Fi), the Ajax control panel (hub) has four independent communication channels to the outside world:
- Dual-SIM (2G/3G/4G): Two SIM cards from different mobile operators ensure that the connection remains stable even if one provider's network fails.
- Ethernet: Wired connection for maximum reliability and bandwidth.
- Wi-Fi: As an additional backup channel (not as the primary security channel).
These four channels work on the principle of redundancy: if one channel fails, the next takes over immediately. An attacker would have to disable the mobile networks of two providers, the Ethernet cable and Wi-Fi simultaneously to interrupt communication – a scenario that is practically impossible.
Important: the Jeweller wireless system for internal communication between sensors and the hub is completely independent of all four external channels. Even if all internet connections fail, the sensors continue to communicate with the control panel and trigger sirens and actions locally. Your home's protection remains fully active even during a complete internet outage.
Because the Jeweller wireless protocol operates at 868 MHz – a completely different frequency from Wi-Fi (2.4/5 GHz) – the security system has no impact whatsoever on the speed or stability of your home network. You can continue to stream, work and play at full bandwidth while your security system communicates on its own exclusive channel.
Comparison table: Wi-Fi vs. Jeweller
| Feature | Wi-Fi (2.4 GHz) | Jeweller (868 MHz) |
|---|---|---|
| Frequency band | 2.4 / 5 GHz – overloaded | 868 MHz – dedicated, low interference |
| Range (outdoor) | 30–50 m | Up to 2,000 m |
| Range (indoor) | 10–30 m | 100–200 m |
| Sensor battery life | Weeks to months | Up to 7 years |
| Jamming detection | None – silent failure | Immediate detection + alarm + frequency change |
| Encryption | WPA2/WPA3 (password-dependent) | AES with dynamic keys |
| Frequency hopping | No (fixed channel) | 17 frequencies in 4 bands |
| Anti-spoofing | Limited | Device authentication per session |
| Router dependency | Yes – router failure = system failure | No – completely independent of the router |
| Impact on home Wi-Fi | Yes – consumes bandwidth | No impact whatsoever |
| Max. devices per hub | Limited by router capacity | Up to 200 devices |
| Communication channels | 1 (Wi-Fi) | 4 (Dual-SIM + Ethernet + Wi-Fi) |
Conclusion – Why radio is the better choice
The choice between Wi-Fi and a dedicated wireless system is not a matter of taste but one of security. Wi-Fi was developed for convenience – Jeweller for protection. Its superiority is evident in every single category: range, battery, interference resistance, encryption, scalability and independence.
A Protexium security system with Jeweller wireless is an investment in reliability that pays off in an emergency. Because an alarm system that can be disabled by a 20-euro jammer is not an alarm system – it is an illusion of security.
For detailed advice on which system suits your property, use our free security analysis. You can find out more about our intrusion protection solutions on the Intrusion protection with active defence page.
Sources & further reading
- Ajax Systems – Jeweller wireless protocol documentation
- ETSI EN 300 220 – European standard for short-range devices (868 MHz)
- BSI – German Federal Office for Information Security – recommendations for wireless security
- Ajax Systems – Anti-jamming technology in detail
- Ajax Systems – Jeweller: how wireless technology works for security
