Reducing Human Exposure to Radio Frequency Emissions

Some people refer to this as “radiation”.  In the industry we also use the term “radio frequency emissions”.

Human exposure to radio frequency emissions from mobile phone devices (mobile phones, pocket WIFI routers, tablets with cellular and WIFI radio connections etc.) is a very publicized topic and hot debate amongst cellular operators, vendors and users.  Furthermore, in NZ and Australia a set of standards (NZS 2772.1:1999) is used to set limits for exposure to the radio frequency radiation produced by all types of radio transmitters, for people exposed at work and for the general public.

The limits are based on careful review of the research into the health effects of exposure to radio frequency radiation, and include wide margins of safety. NZS 2772.1:1999 also sets basic restrictions on the amount of radio frequency absorbed in the body.  This is measured as the “specific absorption rate” (SAR) – the rate at which radio frequency radiation is absorbed in the body, measured in watts per kilogram (W/kg). And we can keep getting more technical, but that’s not the purpose of this page, as we have a simple solution to reduce exposure to you (below), but if you would like to know more you can visit the Ministry of Health page here .

It is quite difficult to quantify and measure specific user exposure limits in the field for many reasons. Some may include:

  • The distance varies on how close the RF device is to the body and in particular which part of the body.

  • There are different modulation technologies used (eg UMTS and LTE) which pulse differently and therefore real power needs to be considered.

  • How far the user is away from the cell site or more importantly how hard the radio transmitter in the device is working to get back to the cell site.  The lower the coverage level, the harder your device has to transmit back (so higher RF power).

  • The duration of the call or RF internet connection.

  • The physical design of the device being used.  This means some positions or angles from the device will have higher emission levels than other positions.

  • How many base stations the RF device is talking to at once.

  • Radio site capacity.  If a base station has lots of capacity you will be able to upload and download more information faster, which again means greater emissions.

The good news is when calculating human exposure, the operators of networks and designers of the smart devices use worst-case scenarios to calculate human exposure.  So, for example when the device is at maximum transmit power, full upload speed, and closest position to the body etc.  But our point here is it is important to understand which factors affect how much radiation you are exposed to.

Another important factor to understand is there typically two radio paths from a cellular device to a base station. So, for those of you living next to a cell tower you might be more concerned about the RF emissions from the Base Station outward (Down) to all users connected to the base Station. This is referred to as “Downlink” radio path.  The other path we refer to is the Uplink Path, and this is the RF emissions from your smart device transmitting up from your device to the nearest base station.  Because your device is close to you, in >99% of all cases it is this Uplink Path which exposes you to the most radio emissions (radiation).  For example, if we look at a typical smartphone transceiver, the receiver can measure as high as say -40dBm, compared to the transmitter which can go to +23dBm.  The difference between -40 and +23 is over 60dB, which is equivalent to 1,000,000x (1 Million) difference in signal level.  So, we will only focus on the Uplink Path (radio transmitter in your device).

So how do we reduce Uplink Path Radio Frequency Emissions?

Well, it’s actually quite easy.  If we reduce the radio loss between your device and the base station it means your Uplink radio path doesn’t have to work as hard (so transmits at lower power). Which means less radio exposure to you and any person around you.  And your device is always trying to use the lowest signal it can (over 1000x a second!). So, it’s important to reduce the signal loss from your smart device to the Base Station using a Cellutronics antenna.  To explain this better we have summarised this for each of our popular applications below.

Home/office booster kits

In a typical home/office application using one of our genuine Cellutronics antennas we can improve the radio Uplink path by about 30dB.  30dB is equivalent to a 1000x improvement in signal level.  So, this means we can reduce the radio emissions Uplink path to you by 1000 times, which is a lot!  If you use our passive repeater kit the radio emissions are even further reduced as your devices are placed on the passive radiator pad which increases the physical distance from the user to the transmitter which typically reduces the radiation by a further 100x or more. 

If you are a data user you can connect one of our home/office antennas directly to a smart router device such as the B315 4G modem, or a pocket WiFi device like the Spark Aircard 800s or the Vodafone/2Degrees E5573. This means you are taking >99.9% of all the cellular radio Uplink emissions and piping them up to your Cellutronics antenna up on your roof away from you and your family

 

Marine booster kits

Typically, we can improve signal level by about 20dB so this means a 100 times reduction in radio emissions to you.

 

Vehicle, Motorhome, Portable and Camping kits

Depending on your exact application signal improvement is typically 10-16dB, so this means somewhere between 10 and 40 times in reduction in radio emissions.

 

We hope that information was helpful to you and if you have any further questions or suggestion on how to make this page better, please contact us.  Similarly, feel free to quote any of this information in any studies or reports you may be working on.