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Intrusion Detection System and Alarm Systems: Pros and Cons

Key Takeaways

  • A home intrusion detection system, or home alarm system, identifies unusual or unauthorized motion on a property and sends an alert. 
  •  There are multiple technologies for home intrusion detection currently on the market, including smart cameras and wireless sensing. 
  •  When deciding which intrusion detection system is best for your home, consider a range of factors including cost, privacy and integration with other smart home functions and devices. 

Home alarm systems are becoming the norm, with SafeHome reporting in 2023 that 72 percent of homes have an alarm system in place. In this article,  we look at the main types of home detection intrusion systems (also called simply ‘home alarm systems’ or ‘home security systems’) available on the market. We identify the pros and cons of the different technologies and offer some tips on choosing the system that is right for you. 

What Is a Home Intrusion Detection System?

Intrusion detection is the key function of any home alarm system. Once detected, the homeowners or security personnel can be alerted of unauthorized entry and can take appropriate action. 

Intrusion detection might be incorporated into a purpose-built device, or it might be included in smart devices with multiple functions. Depending on the system in question, it might work by monitoring various entry points and areas, such as doors, windows, and motion-sensitive zones, or it may monitor the entire space. 

A home intrusion detection system sits alongside other key measures (such as appropriate locks, lighting and selective disclosure of personal details online) to make your home as secure as possible. 

What Are the Different Technologies for Home Intrusion Detection?

A variety of different technologies are available for detecting intrusion in the home: 

  • Motion detection systems. This includes Passive Infrared (PIR) Motion Sensors, that detect the heat radiated by moving objects and wireless sensing, which identifies disruptions to wireless network (WiFi) signals in the home. 
  • Contact-Based Sensors. On the application of physical pressure, or the breaking of an electrical connection on a door or window frame, the alarm is raised. 
  • Video-Based Systems. Closed-circuit cameras can be used to detect intruders both manually (through active surveillance by someone watching the feed), or automatically through smart cameras that pick up unusual types of movement. Increasingly these systems have AI-powered features like facial recognition, and send real-time video feeds to homeowners’ smartphones. 


Wireless sensing in intrusion detection systems

Wireless sensing is a relatively recent motion detection technology that is becoming more common for detecting intruders. A wireless sensing system detects interruptions to wireless/Wi-Fi signals caused by motion. Then, smart algorithms within the sensing device are used to filter out false positives (such as the movement of pets or robot vacuum cleaners), indicating a potential intrusion. 

Once the wireless sensing system is armed, it will detect unexpected human motion to a high degree of accuracy. If an intrusion occurs, homeowners and/or security personnel can be immediately notified via a dedicated app

Wireless sensing offers some benefits over some other forms of intrusion detection: 

  • Full coverage. Contact sensors will only be fitted at entry points. Security cameras only ‘see’ what is in their line of sight. Wireless sensing, by contrast, will detect any motion that occurs within its coverage area (often up to 1500 sq ft per device). 
  • Ease of installation. Sensing devices are small, and plug into regular power outlets: No physical alterations to the home are required for full home security. 
  • Integration with other smart home functions. Wireless sensing is a complete motion and presence detection technology — identifying intruders is just one or many applications. Having wireless sensing technology in place allows for general home monitoring (especially falls/unusual movements of elderly family members) and potential energy savings (through the optimization of appliances and heating/cooling based on motion). 
  • Respect for privacy. While smart cameras are excellent at detecting human motion, they are not appropriate in all private spaces within the home. By contrast, wireless sensing does not collect and retain personal information — it is simply identifying disruptions in wireless signals. 

How to Choose a Home Detection Intrusion System?

Given that there are a range of different security systems on the market, how do you choose which intrusion detection system is best for you?

  • Assess your specific security needs.  Consider factors such as the size and layout of your home, the safety of the neighborhood, and the most likely threats you face. You also need to decide whether the intruder detection system should be part of a broader smart home system
  • Work out your budget. A system that is professionally installed and requires extensive alteration to the home might be out of your price range, compared to  a ‘plug and play’ option. 
  • Check for False Alarm Prevention. One of the biggest annoyances for users of home security systems are false alarms. According to recent research, 62 percent of home security system users over the past year experienced false alarms. An intrusion detection system should have features to minimize false alarms, such as automatic filtering of pets and other minor movements. Another basic feature is the ability to differentiate between authorized and unauthorized access.
  • Understand the pros and cons of each technology. For example, cameras can be particularly useful for monitoring motion in outside areas (as they are largely unaffected by weather). By contrast, wireless sensing is particularly useful for ‘non line-of-sight’ motion detection, and detecting motion around physical objects. 
  • Consider which additional features are available. Consider whether you want remote access, smartphone notifications, integration with other smart home devices (e.g., smart locks and lighting), and compatibility with voice assistants.
  • Assess monitoring services. Some intrusion detection systems will have a professional monitoring option. Consider whether you need this option (or whether app notifications to the homeowner are sufficient). If you opt for professional monitoring, pay attention to pricing and response times. 
  • Ask about insurance discounts. Some insurance companies offer reduced premiums for homes with security systems, so it is worth asking. 


Home intrusion detection systems are crucial for homeowner peace of mind: Whether as a standalone device or part of a broader smart home infrastructure, a range of technology is now available to suit your home security needs and budget

For some homeowners, an affordable plug-and-play solution, like wireless sensing will be sufficient. Others seeking more extensive coverage may go for a ‘combined’ smart home system including multiple technologies, like wireless sensing and smart cameras, working in tandem. 


Yes. Many modern intrusion detection systems plug into outlets and can be connected to surfaces without the need for any permanent alterations. While this will alleviate most concerns, it is worth checking with property management or landlords if they have any other concerns with such a system. 

Professional monitoring services are more expensive and may not be necessary in many cases.  It is worth considering factors like average response time and your own availability and distance from home when making this decision