What Is A FHSS Baby Monitor?
FHSS baby monitors are baby monitors that utilize a spread spectrum to digitally transfer signals in the 2.4 GHz frequency, guaranteeing 100% security of the signals in transit. This article explains the FHSS technology and will list a few 2.4 GHz FHSS baby monitors that are secure and almost impossible to hack.
FHSS itself is a short form for Frequency-Hopping Spread Spectrum, abbreviated as FHSS. It is a method of transmitting signals in one frequency band while switching/hopping from one channel(or one sub-frequency) to another. Each frequency band, for example, 2.4 GHz, is subdivided into sub-frequencies which a signal can hop to, or away from as it is transmitted from the baby monitor unit to the receiver/parent unit. FHSS baby monitors are part of wireless baby monitors without wifi or that do not rely on wifi to transmit signals.
History of Digital FHSS Baby Monitors
Patent in 1941
FHSS technology dates its history back to World War 2 when it was used as a secret communication system that guided arms to the target without being detected or intercepted by the enemy. 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.
FCC Regulations in 1980s and Emergence of FHSS
In the late 80s, the Federal Communication Commission allowed unlicensed use of 2.4 GHz frequency band ( Part-15 regulations ). What the regulation did was to allow electronics manufacturers to operate in the 2.4 GHz frequency band without any special license. The 2.4 GHz frequency band, therefore, became very popular with manufacturers of electronics. With several devices using the 2.4 GHz band, many devices experienced a lot of interference and it was not until the FCC allowed some manufacturers who wished to utilize the spread spectrum technology to reduce device-to-device interference.
The two popular methods used are the spread spectrum is Direct-Sequence Spread Spectrum (DSSS) and FHSS. Although it is shared, a successful spread spectrum should allow the baby monitor to experience less interference. Prior to FHSS technology, fixed channel signals had three main problems; jamming, interference, and interception. The 2.GHz FHSS technology solves all the three.
Features of 2.4 GHz FHSS Baby Monitors
1. Superior Security: Almost Impossible to Hack
As the signal travels from one channel to another, it has access points each containing synchronization with parameters necessary for transmitter and receiver to stay in synchronization (Dwell Time, Hop Set, Hop Pattern, Hop Index). For a long period, the spread spectrum was thought to be impenetrable but in 2019, it would be seen as sheer negligence to operate an open 801 networks with no access control. in 2002, Wagner and Boristov Goldberg published a research paper, Intercepting Mobile Communications: The Insecurity of 802.11 and they warned that it would be “dangerous” to “dismiss attack requiring link-layered access as impractical”.
As a signal is transferred from one channel to another the carrier has the parameters that are only known to the encrypting and the decrypting access points
2. Resistance to Interference and Jamming:
FHSS allows for multiple channels to be used and the signals to switch continuously. In order to jam a communication system, the communication frequency has to be known and for FHSS baby monitors, the frequency at any particular point of signal transfer is not known.
FHSS Baby Monitors in the Market.
There are over 20 baby monitors that utilize FHSS technology. These baby monitors are preferred mainly because of 100% security and less/minimal interference. The best-selling baby monitor, Infant Optics DXR 8 is regarded as the most secure baby monitor with virtually no interference, thanks to the FHSS technology.
Infant Optics DXR 8 utilizes 2400 Mhz ~ 2483.5 Mhz frequency transmission range to transfer signals using FHSS spread spectrum described above. Infant Optics DXR 8 uses Gaussian frequency-shift keying (GFSK) modulation with a data rate of 3Mbps and 3.375 channel bandwidth. Infant Optics DXR 8 is currently the best-selling baby monitor mainly because of the features described above, security, and less interference. Infant Optics passed the FCC guidelines of Class B digital devices, pursuant to Part 15 of FCC rules. You can read our full review of Infant Optics DXR 8 and how it has achieved wild success selling over 500,000 units since its launch in 2013.
Eufy Spaceview utilizes a 2.41 – 2.477 GHz frequency range to transfer the signal using the FHSS spread spectrum. It uses GFSK modulation and a PCB antenna. As per the FCC testings in August 2018, Eufy Spaceview has a maximum scaled SAR (w/kg) of 1.804 w/kg and a limit of 4.0 w/kg. Read our full review of this Eufy Spaceview FHSS baby monitor that has challenged the Infant Optics DXR 8 model with its 720p HD screen.
3. Philips Avent FHSS Video Baby Monitor
Philips Avent FHSS Video Baby Monitors (SCD630/37) is one of Philips Avent’s baby monitors that use the spread spectrum technology in the 2.4 GHz frequency band.
Since its launch in April 2017, Philips Avent FHSS video baby monitor has maintained a steady monthly sales volume of about 300 units.
4. Motorola MBP36S FHSS Video Monitor
Motorola MBP36S FHSS baby video monitor is our 4th FHSS baby monitor. Like the rest, it uses the 2.4 GHz frequency to transmit signals using the spread spectrum which has less interference and 100% security and privacy.
Comparison of FHSS Video Baby Monitors
|Infant Optics DXR 8 - FHSS Video Baby Monitor||Eufy Spaceview - FHSS Video Baby Monitor||Philips Avent |
FHSS Video Baby
|Picture of FHSS |
|Frequency Spectrum||2.4 GHz FHSS to 2.483 GHz FHSS||2.41 GHz FHSS to 2.477GHZ FHSS||2.4 GHz FHSS||2.4 GHz FHSS to 2.48 GHz FHSS|
|Range||700 ft||460 ft||1000 ft.||590 ft.|
|FHSS Modulation||GFSK||GFSK||Not listed||Not listed|
|FHSS Data Rate||3 Mbps||Not listed||Not listed||Not listed|
|FHSS Channel Bandwidth||3.375||Not listed||Not listed||Not listed|
|Recommended Distance Away from Body||20 cm||20 cm||3.4 inches or 20 cm||20 cm|
|Infrared||Automatic||Manual Switch On/Off||Automatic||8 pcs of IR LEDs|
|Screen Size||3.5"||5"||3. 5"||3.5" diagonal TFT LCD|
|Year and Month|
of Release to
|Not listed||September 2018||April 2017||N/A|
|Price on Amazon||Check Price||Check Price||Check Price||Check Price|
Video Explanation of FHSS Technology.
The video below explains how the FHSS technology works and how it can be utilized by FHSS baby monitors.
FHSS Vs. DECT Baby Monitors
FHSS baby monitors use the 2.4 GHz frequency band and there is another telecommunication technology that uses 1.9GHz frequency and used in DECT baby monitors. DECT is an abbreviation for Digital Enhanced Cordless Telecommunications, a technology mostly designed for voice data communications. Both FHSS and DECT baby monitors are digital wireless baby monitors that use different frequency bands to transmit signals from the baby unit to the parent unit. FHSS uses the 2.4 GHz frequency band while DECT uses the 1.9 GHz, frequency band. While DECT technology has its origin in Europe, it is currently being used worldwide with the FCC approving it for use in the US in 2005. It is also referred to as DECT 6.0 in North America. You can read our post on 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|
|Licensed to||Several range of devices||Radios/Telecoms|
|Formerly called||N/A||Digital European Cordless|
|Example of baby monitor||Infant Optics DXR 8, Eufy Spaceview, Motorola MBP36XL||Panasonic long range baby monitors,|
Video Explanation of FHSS Technology
In our 2019 list best non-wifi baby monitors, we selected baby monitors that use this FHSS technology. You can check out our detailed review and comparison of all the leading FHSS non-wifi baby monitors.
I am Ashley Davis, a mom of three kids and the editor here at 10BabyGear. I have been a parent since 2011 and have been doing full-time consulting as a baby sleep expert since 2019. When I am not researching or testing the next baby gear hitting the market, you’ll find me teaching my toddlers a trick or two – especially over the last few months with the lockdown. I hope you’ll find my guides and reviews helpful as you make your next purchase decision. If you have any questions, you can reach me at firstname.lastname@example.org.