How alarm systems are ‘hardened’ against jamming

Jamming has become a real threat for alarm users. Criminals are known to use jammers to inject radio signals or noise into the communication paths between sensors and the alarm panel, thus incapacitating the system and making break-ins easier. Solutions that protect the system from jamming, then, become critical. Luckly, today’s alarm systems already come with various defense measures against jamming. These features are summarized as follows.
 

Multiple communication paths

 
Many alarm systems today have multi-channel communication capabilities so that if one channel is jammed, the hub and the sensors can still talk to each other over other channels.
 
“A reliable security system should not rely on a single communication path, because risks vary at each level of the system. For communication with the outside world, it is important to have multiple channels available,” said Sean Lai, Cluster Director for ASEAN at Ajax Systems. “That is why Ajax 4-port hubs support multiple communication options simultaneously, including wired Internet, Wi-Fi, and two 700 MHz bands. If one channel becomes unavailable, the system can continue transmitting events and alarms through another.”
 
Mia Zhao, Marketing Director at Roombanker, also mentions the importance of multi-channel communication. “Support for multiple channels, for example Ethernet, Wi-Fi, and cellular, ensures that if one path is disrupted, alarm signals can still be delivered through alternative routes,” she said
 
As an example, Zhao cites Roombanker’s Home Security Hub. “It supports multiple communication paths including Ethernet, Wi-Fi, and Cellular LTE, ensuring continuous connectivity with alarm centers and the RB-Link mobile app. In normal operation, if one communication channel is disrupted – for example, Wi-Fi – the system can automatically switch to alternative paths such as Ethernet or cellular, maintaining uninterrupted alarm transmission,” she said.
 
Zhao also highlights the importance of local alarm capability during connectivity loss, so that the system can continue to trigger sirens and record events even if external communication is temporarily unavailable.
 
She again cites Home Security Hub as an example. “If all external communication channels are lost, for example due to network failure or intentional disruption, the system will report a connection loss to the server once possible, while continuing to operate locally. During this time, it can still trigger sirens and record alarm events, ensuring that on-site protection remains active even when remote communication is unavailable,” she said.
 

Frequency hopping

 
Frequency hopping is another key anti-jamming feature in alarm systems. The basic idea is that the hub and the sensors rapidly switch or hop between different frequencies, making it much harder for a jammer to block the communication.
 
“Radio frequency hopping … is used across Ajax wireless communication, with enhanced protection in Superior Jeweller to meet Grade 3 requirements, and in standard Jeweller for Grade 2 systems,” Dai said. “This approach is especially valuable for high-risk commercial sites, retail, offices, warehouses, and critical infrastructure, and it also provides homeowners with an extra layer of protection through early detection and instant alerts.”
 
“Frequency hopping rapidly switches channels to reduce the impact of targeted interference,” Zhao said. “For communication between detectors and the hub, which is the most sensitive part of a wireless system, we use our proprietary RBF wireless protocol operating in the Sub-1GHz band. This layer is inherently more exposed to interference, so the protocol is designed with multiple anti-interference mechanisms to enhance reliability. These include frequency hopping as well as time-division communication, listen-before-talk, robust modulation and signal design and encrypted communication.”
 

Detection of jamming at the device level

 
While it’s important that alarm systems can detect jamming, this capability is not limited to just the hub. It can be extended to the device level as well.
 
“In Ajax systems, jamming can also be identified by devices themselves. At the device level, Ajax hubs and Superior sirens can detect signs of jamming by analyzing the radio spectrum. If abnormal interference is detected, the system sends an alert. We also regularly check the connection with every device, so if communication is lost, users are notified right away,” Dai said.
 

Hub-to-monitoring center communication

 
It’s important to note that the aforementioned measures are intended to counter jamming within the alarm system. Yet the path between the panel and the monitoring center is also subject to jamming attacks and needs to be protected as well. A recent integration between DMP’s JamAlert and Interface Systems’ TamperShield managed alarm service provides a solution in this regard.
 
“DMP’s JamAlert is designed to monitor the cellular frequencies used by alarm systems and detect abnormal signal spikes associated with a nearby jammer, while Interface TamperShield monitors panel heartbeat communications at the ISOC (Interactive Operations Center) to identify a loss of connectivity quickly. Interface then adds live video verification and faster escalation, including staff notification, law enforcement dispatch, and voice-down deterrence when a credible threat is confirmed,” said Aaron McGhee, Senior Manager of Product Management at Interface Security Systems.
 
McGhee mentions the types of end user entities the solution is suitable for. “While the underlying issue of signal interference is not limited to one type of property, Interface’s solution is designed for commercial and retail environments where a disrupted alarm signal can have serious operational and financial consequences. The focus here is on giving businesses earlier visibility into a jamming event and a faster, more coordinated response,” he said.
 

Best practices

 
Finally, there are certain best practices that alarm system users can follow to make jamming less likely to succeed.
 
“The user should install the hub in a protected, less accessible location; enable push notifications and remote alerts; use systems with encrypted communication protocols; and combine intrusion detection with video verification where possible,” Zhao said.
 
“Best practice is to treat jamming as one part of a layered design: use redundant wired and cellular paths where practical, monitor panel health continuously, test regularly, and pair alarm alerts with video verification so operators can quickly determine whether a jamming event is part of an active intrusion,” McGhee said.