Today I wanted to address a serious concern regarding wireless video surveillance – both gsm and wifi solutions.
Wireless surveillance presents a glaring vulnerability
There is a major obstacle to using wireless transmission security cameras for mission critical video surveillance. Why? These cameras can be disabled with a cheap cell phone or signal jammer, leaving your mission completely vulnerable. There are some work around, non of them simple, and non of them guarantee success.
The complexity of defending against wireless jamming.
If you ask most wireless surveillance proponents, how to defend against wireless jamming, they instinctively jump to the recommendation of strong passwords, renewing passwords, strong encryption and other methods similar to this. You have to point out to them that these methods simply protect the data content and access to the network – but do not necessarily prevent the complete blocking of the signals on the network, potentially shutting down your system.
Cell phone jammer for instance , work by emitting radio signals that interfere with the communication between a cell phone or sim card equipped device and the cellular base station – effectively disrupting the communication channel. It is not the attackers objective to breach the network, rather to disable it so that the facility is rendered unmonitored. This likewise applies to wifi operated devices.
Right here it should be said. Its extremely difficult and complex to defend again such an attack. Even when complex defense mechanisms are put in place. We have seen military grade attacks by coordinated criminals, using sophisticated jamming equipment, even in residential home attacks.
Some common strategies employed to defend against wireless Jamming.
1. You can deploy a signal jamming detector. This device will alert you to the presence of a jammer in your area.
2. A directional antenna can help you focus your signal in a specific direction, making it less likely to be disrupted by a jammer. The focused beam signal is stronger when compared to an omnidirectional antenna, making it slightly more difficult to disrupt the signal. Jammers with enough power or with omnidirectional dispersion patterns themselves, can still be used to disrupt the signal.
3. Frequency hopping spread spectrum (FHSS) devices are designed to be resistant to jamming. The technology rapidly switches the frequency of the signal being transmitted, forcing the jammer to continuously predict the frequency that should be jammed. FHSS is very effective against simple jammers that target a specific frequency. Sophisticated jammers can likewise employ scanning techniques to predict the hopping sequence and disrupt the signal. Where the FHSS device hops between a small number of channels, a jammer can potentially cover all the channels and disrupt the communication.
FHSS is a complex system to deploy. While it does offer protection against simple jammers, it’s vulnerable to more sophisticated jamming devices.
4. Direct Sequence Spread Spectrum (DSSS) is a powerful anti-jamming technique. This technique spreads the signal over a wide frequency range, making it extremely difficult for a jammer to interrupt the signal. DSSS is complex to deploy, and because of the wide frequency range used, it demands much more bandwidth than standard cameras.
Recommendations from the experts.
From your video surveillance provider, here is our recommendation;
Given the challenges and complexity called for to secure a wireless surveillance network – we recommend prioritizing wired connections. Whenever possible use wired Ethernet or Fibre connections for your cameras.
If you go ahead with a wireless solution – which is not a good strategy, if you are protecting mission critical or high value facilities, then you must implement a multi-layered approach that combines both physical and technological measures.
- Consider using cellular backup for critical cameras. This provides an alternative communication channel if your WiFi signal is jammed.
- Local storage, in the form of SD cards onboard the camera, will continue recording during a jamming event.
- Depending on the criticality of the system you are monitoring , consider installing a signal jamming detector and develop a response plan should you receive alerts about signal jamming. Or insist on DSSS capable cameras and equipment, and make allowance for the extra bandwidth demand.
Conclusion
Securing against wireless jammers is complex, requiring a layered approach. While techniques like FHSS, directional antennas, and even encryption offer some protection, they have limitations. Video surveillance consultants should prioritize wired connections, local storage, and a multi-pronged security strategy to enhance resilience against jamming attempts. Remember, no single solution is foolproof, but vigilance and a layered approach can significantly improve security.
