Baby Monitors Guides

How FHSS Innovation is Powering Secure Baby Monitors

Ashley Davis

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FHSS, DECT, and DSSS are all digital baby monitoring technologies that represent great progress in communication tech to enhance baby safety.

FHSS technology is among our favorite baby safety innovations as it has proven a great solution to hacking incidences thanks to its superior transmission process coupled with other security features such as encryption.

About Baby Monitor Transmission Tech and Innovations:

The continuous development of these technologies reflects a growing emphasis on not just maintaining but enhancing the security, reliability, and quality of baby monitoring systems. Manufacturers are leveraging advancements in encryption, frequency hopping patterns, and signal processing to offer parents peace of mind.

All these technologies have gone through various improvements to optimize their performance, reliability, and security, making them indispensable in the context of baby monitoring systems. Let’s delve deeper into how each technology contributes to baby safety:

  1. Frequency Hopping Spread Spectrum (FHSS): This technology enhances privacy and reduces interference by rapidly switching the frequencies used for communication. Originally developed for military applications, FHSS makes it difficult for eavesdroppers to intercept or jam communications, offering a secure way to monitor babies. Over the years, improvements in FHSS technology have focused on making frequency switches faster and more unpredictable, thereby increasing the security of the transmission. Additionally, enhancements in signal processing have allowed FHSS systems to provide clearer audio and video signals, even in environments with a lot of wireless interference.
  2. Digital Enhanced Cordless Telecommunications (DECT): DECT technology is widely used for voice communication in baby monitors, offering high-quality audio free from interference from other household devices. DECT operates in a frequency band specifically reserved for voice communication, minimizing the chances of interference from Wi-Fi networks, microwaves, and other common sources of electronic noise. Recent advancements in DECT technology have included the integration of more robust encryption methods to prevent unauthorized access to audio transmissions, ensuring that only parents and authorized users can listen in on the baby’s room.
  3. Direct Sequence Spread Spectrum (DSSS): Similar to FHSS, DSSS is a spread spectrum technology that spreads the signal over a wider bandwidth, making it more resistant to interference and eavesdropping. DSSS provides a stable and secure connection for baby monitors, with improvements focusing on enhancing signal integrity and security measures. Recent updates have seen the adoption of more sophisticated encryption algorithms and the implementation of features designed to minimize signal dropout, ensuring continuous monitoring without gaps in coverage.

FHSS Baby Monitors:

What is FHSS Baby Monitor?

FHSS baby monitor is a baby monitors that utilizes a sophisticated transmission technology which relies on dynamic frequency selection by rapidly switching (hopping) the carrier frequency of the transmitted signal across a wide spectrum in a pseudorandom sequence.

This sequence is synchronized between the transmitter (the baby unit) and the receiver (the parent unit), making the communication highly resistant to interference and nearly impossible for unauthorized entities to intercept or decode. On top of hopping, FHSS monitors use enhanced encryption protocols, unique synchornization codes, adaptive frequency management, efficient bandwith utilization to gain stable communication channels with minimal multipath inteference.

Frequency Hopping Spread Spectrum (FHSS) technology is a method of transmitting radio signals by rapidly switching the carrier frequency among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. This approach makes the transmission far more resistant to interference and eavesdropping compared to traditional fixed-frequency transmissions.

Here’s a detailed look into FHSS innovation and its central role in baby monitoring technology:

Advancements in FHSS Technology

Over time, FHSS technology has seen significant advancements, especially in its application to consumer devices like baby monitors. Some key improvements include:

  • Enhanced Security: Early FHSS systems provided security through obscurity, relying on the unpredictability of the frequency hopping pattern. Modern FHSS-based baby monitors now incorporate advanced encryption protocols in conjunction with frequency hopping. This dual-layer security approach ensures that even if someone were to intercept the signal, deciphering the content would be extremely difficult.
  • Improved Signal Quality: Advances in signal processing have significantly enhanced the audio and video quality of FHSS baby monitors. These improvements allow for clearer, more stable transmissions, even in environments crowded with wireless signals. Noise reduction techniques and better data compression algorithms have also contributed to this enhancement.
  • Increased Reliability: Modern FHSS systems are designed to identify and avoid interference from other wireless devices automatically. By dynamically adjusting the hopping pattern or temporarily avoiding certain frequencies with high interference levels, FHSS baby monitors can maintain a strong and reliable connection.

FHSS was an improvement from analog systems which used fixed frequency that make it easy for anyone with a basic receiver tuned to that frequency to intercept the communication. Analog also lacked sophisticated encryption and are very easy to detect and intercept due to their continuous transmission on a single frequency.

Benefits of Using FHSS in Baby Monitors:

Let’s break down these components for a clearer understanding of their technical and practical implications:

Dynamic Frequency Selection and Frequency Hopping

  • Rapid Switching (Hopping): The signal frequency changes many times per second according to a pseudorandom sequence, making it difficult for eavesdroppers to track or intercept the signal.
  • Pseudorandom Sequence Synchronization: Only the transmitter and receiver, which share the sequence, can predict the next frequency, ensuring private communication.

Enhanced Encryption Protocols

  • Security Layer: On top of the inherent security provided by frequency hopping, additional encryption safeguards the data, making unauthorized access even more challenging.
  • Data Protection: Encrypted data transmission ensures that sensitive audio or visual information is securely conveyed, protecting the privacy of the monitored infant and family.

Unique Synchronization Codes

  • Pairing Mechanism: Devices use unique codes for synchronizing frequency hopping patterns, effectively creating a secure and dedicated channel for communication.
  • Reduction in Signal Clashes: This unique pairing minimizes the risk of interference from other devices, ensuring a clear signal.

Adaptive Frequency Management

  • Interference Avoidance: The system can dynamically identify and evade congested frequencies, thereby optimizing the quality and stability of the communication link.
  • Enhanced Reliability: By actively avoiding interference, the monitor maintains a consistent connection without drops or quality degradation, critical for continuous monitoring.

Efficient Bandwidth Utilization

  • Spread Spectrum Technology: By spreading the signal over a broader frequency band than needed, FHSS monitors are more resilient to interference and eavesdropping.
  • Spectrum Efficiency: This approach maximizes the use of available bandwidth, facilitating high-quality transmissions even in environments with numerous competing signals.

Minimized Multipath Interference

  • Signal Clarity: The technology’s resistance to multipath interference, where signals reflect off surfaces and cause distortion, ensures the transmitted signal remains clear and undistorted.
  • Reliable Transmission: Ensures that audio and video feeds reach the parent unit with minimal latency and clarity, essential for monitoring an infant’s well-being.

The technology was patented in 1941 by Markey Hedy Kiesler and Antheil George and the technology allowed the sender to transmit audio signals in a pseudo-random pattern utilizing 88 different sub-frequencies. Some sources claim that a German physicist and electrical engineer Jonathan Zenneck had discovered it earlier and had mentioned the concept in print in 1908.

There have been two variations of FHSS technologies utilized in baby monitors, the FHSS 1.0 and FHSS 2.0. Our best FHSS baby monitor which utilizes the latest FHSS 2.0 technology with superior data encryption is Infant Optics DXR 8 Pro and is the safest.

Challenges of FHSS Technology in Monitoring Systems:

  • Synchronization: For the sender and receiver to successfully communicate using FHSS, they must be synchronized. If the synchronization is not precise, it can lead to data loss and errors.
  • Channel interference: In dense wireless environments, there may be interferences from other FHSS systems or non-FHSS devices that could impact the quality of transmission.
  • Limited range: FHSS technology has a limited range as it uses lower power output compared to other wireless technologies like Wi-Fi. It is suitable for short-range communication.
  • Complexity: Implementing FHSS technology can be complex and require specialized equipment, making it more expensive than other wireless technologies.

Other Uses of FHSS Technology:

  • Military communications: One of the main uses of FHSS technology is in military communications due to its high level of security. The signal hopping makes it challenging for enemies to intercept and decode transmissions.
  • Wireless LANs: FHSS technology is used in wireless LANs, providing secure communication with minimal interference from other devices in the same frequency range.
  • Medical applications: Due to its resistance to interference and high security, FHSS technology is used in medical applications such as remote patient monitoring and wireless medical devices.
  • Industrial and home applications: FHSS technology is used in industrial automation and control systems, providing reliable and secure communication for critical operations. Some baby monitors we review here at SaferForBaby utilize FHSS.

Explanation of FHSS Technology.

The video below explains how the FHSS technology works and how it can be utilized by FHSS baby monitors.

Which Baby Monitors use FHSS?

Baby monitors that utilize FHSS are all the brands that we featured in our reviews of best non-wifi baby monitors including Helloaby, Babysense, Infant Optics Pro, LeapFrog, Anmeate and Eufy Spaceview Pro. Below is the list.

  • Eufy SpaceView Pro: Utilizes FHSS 2.4 GHz Frequency.
  • Infant Optics DXR-8 Pro: Recognized for its high-tech features among non-Wi-Fi baby monitors and marketed as having second-generation FHSS technology.
  • Anmeate Video Baby Monitor: Offers the best value in non-Wi-Fi baby monitoring solutions.
  • Babysense HDS2 Baby Monitor: Ideal for monitoring twins, standing out as the best non-Wi-Fi option for this purpose.
  • HelloBaby HB6550 5-Inch Baby Monitor: Noted for its portability, making it the best portable non-Wi-Fi baby monitor.

Other Baby Monitor Technologies:

DECT: Digital Enhanced Cordless Telecommunications

Another popular technology used in baby monitors is DECT, which operates on a different frequency band than FHSS technology which operates in the 2.4 GHz frequency.

DECT baby monitors operate on the 1.9 GHz frequency range and use digital encryption to secure communication between the parent unit and the baby unit. The key advantage of DECT over FHSS is that it has a longer range of transmission of up to 50 meters indoors and up to 300 meters outdoors compared to FHSS which does not exceed 30 meters indoors and around 120 meters outdoors.

DECT’s standard encryption is 64-bit while the minimum standard encryption for FHSS is 128-bit making FHSS much more secure. You should, however, note that when using the DECT repeater, encryption is no longer in place. On the other hand, DSSS monitors can use up to the highest encryption standard of 256-bit.

DECT are mostly used in cordless phones and have been adapted for use in baby monitors due to their reliable and secure communication.

However, it’s important to note that DECT technology is also not immune to hacking. In 2008, a team of researchers discovered vulnerabilities in certain DECT devices.

While encryption is included in the DECT standard, it can still be easily bypassed. This allows rogue devices to impersonate legitimate ones, as reported by Heise Security. It is possible that all DECT devices now have more secure encryption and are no longer vulnerable. It is, however, clear that DECT security settings are not at par with FHSS’s settings.

FHSS Vs. DECT Baby Monitors

Below are some other differences between the two technologies, FHSS and DECT:

Feature FHSS Baby Monitors DECT Baby Monitors
Frequency Band 2.4 GHz 1.9GHz
Spread Spectrum Yes Yes
Wi-fi No No
Licensed to Several range of devices Radios/Telecoms
Discovered in America Europe
Formerly called N/A Digital European Cordless
Encryption 128 or 256-bit 64-bit
Example of baby monitor Infant Optics DXR 8, Eufy Spaceview, Motorola MBP36XL Panasonic long range baby monitors,

DSSS: Direct Sequence Spread Spectrum

DSSS, an acronym for Direct Sequence Spread Spectrum, is a technology that builds upon FHSS (Frequency Hopping Spread Spectrum). Unlike FHSS, which hops between frequencies and sends data in bits, DSSS transmitters transmit data at once across an entire spectrum of frequencies.

DSSS has a few advantages over FHSS.DSSS revolutionized transmission by utilizing bulk transfer with data broken into bits. Instead of transmitting one bit at a time, DSSS breaks down each bit into smaller, more manageable chunks. These chunks are then processed by an algorithm to determine their values. Once transformed into wireless bits, they are transmitted across the airwaves.

Upon reception, a receiver captures these bits and uses a corresponding algorithm to convert them back into the original data. This innovative approach not only improves the efficiency of data transmission but also ensures the integrity of the transmitted information.

Here is the key difference between FHSS and DSSS. DSSS and FHSS differ primarily in their approach to frequency hopping during data transmission. FHSS hops between frequencies while transmitting data, whereas DSSS simultaneously sends data on every frequency within the designated spectrum at once.

Although DSSS incorporates built-in parity, it lacks superior resilience. Interestingly, FHSS demonstrates greater resilience compared to DSSS. In highly noisy and congested environments, FHSS outperforms DSSS-encoded baby monitor signals, highlighting its superior capability.

Similar to FHSS, DSSS uses the 2.4 GHz frequency but can also switch to the more recent 5 GHz frequency band.


Does Bluetooth use FHSS too?

Bluetooth utilizes FHSS, while Wireless USB, 802.11b/g/a (commonly known as Wi-Fi), and 802.15.4 ( ZigBee) employ DSSS. All of these technologies operate within the globally available ISM frequency band (2.400-2.483 GHz). ISM is an abbreviation for Industrial, Scientific, and Medical, referring to the frequencies reserved for non-communication purposes

Is DSSS same as Wi-Fi?

No, DSSS is not the same as Wi-Fi. Wi-Fi is a type of wireless technology that uses DSSS or other modulation techniques, depending on the specific standard being used. For example, 802.11b/g/a Wi-Fi utilizes DSSS while newer standards such as 802.11n and 802.11ac use different methods such as OFDM (Orthogonal Frequency Division Multiplexing).

Why is FHSS more secure than DSSS?

FHSS is considered more secure than DSSS due to its frequency hopping mechanism. By constantly changing frequencies during data transmission, it makes it difficult for eavesdroppers to intercept and decipher the information being transmitted. Additionally, since FHSS only transmits small amounts of data at each frequency, it is more difficult for attackers to capture and decrypt the entire message.

Can FHSS be hacked?

While FHSS is generally considered more secure than DSSS, it is not completely hack-proof. With advanced technology and techniques, and close physical proximity to the FHSS device, hackers can intercept and decode FHSS transmissions. However, compared to DSSS which is more susceptible to hacking due to poor encryption, FHSS offers an extra layer of security that makes it a preferred choice for applications where data privacy and security are crucial.

What are the differences between OFDM and DSSS?

OFDM (Orthogonal Frequency Division Multiplexing) and DSSS (Direct Sequence Spread Spectrum) are both modulation techniques used in wireless communication. OFDM is used in newer standards of Wi-Fi such as 802.11n and 802.11ac, while DSSS is utilized in older standards like 802.11b/g/a.

The main difference between OFDM and DSSS is the way they transmit data. DSSS spreads data over a larger bandwidth by using a specific code, making it easier to intercept and decipher. On the other hand, OFDM divides data into smaller sub-channels and transmits them simultaneously at different frequencies, increasing the overall throughput and making it more difficult for attackers to hack.

Additionally, OFDM uses complex coding and modulation techniques to provide an extra layer of security.

Why is FHSS a better choice for certain applications?

While DSSS can offer higher data rates, FHSS is preferred for applications where data security is crucial. For example, military communication systems or medical devices that transmit sensitive information require high levels of encryption and protection against hacking. In such cases, FHSS is a better choice due to its frequency-hopping mechanism and stronger encryption.

Moreover, FHSS offers better resistance to interference since it constantly changes frequencies, making it difficult for interfering signals to disrupt the transmission. This makes it suitable for crowded environments with multiple wireless devices.