Technology In this feature mobile phones testing procedures trading standards responsibilities Ring of confidence The rapid march of technology over the last 20 years has often left regulators playing catch-up to keep consumers safe, but more attention needs to be paid to non-compliant communication devices, writes Jean-Louis Evans A large and growing number of devices now use wireless radio transmitters to send and receive information. Statistics from the International Telecommunication Union (ITU) the leading United Nations agency for information and communication technology show that global mobile-cellular subscriptions (that is, the number of people that have registered mobile phones) will reach almost seven billion by the end of 2014. Mobile phones are now so ubiquitous that its easy to forget the safety concerns that circulated in the late 1990s. Yet with this widespread use of mobile technology, consumers and governments are once again becoming aware of the potential health risks of radio frequency (RF) energy emissions. As a result, strict regulations apply when these devices come into contact with the human body particularly in the European Union (EU), the US, Canada and Australia. With new technologies and manufacturers coming on the scene, its more important than ever for regulators to know what the rules are and what responsibility they have for enforcing them. Andrew Abercrombie of Hampshire Trading Hampshire County Council Standards makes this clear: Hampshire County recently had a number of Council recently had a number of smartphones smartphones tested for tested for radiation output. radiation output. Many trading Many trading standards services may not realise standards services may not realise that they have some responsibilities for this aspect of that they have some responsibilities the legislation. The smartphones we had tested for this aspect of the legislation passed the screening tests applied. However, other authorities may like to look at this aspect of product safety. What is SAR? EU REGUL ATIONS In the European Union, SAR standards that apply to mobile phones are: G EN 50360 Product standard SAR (specic absorption rate) is a measurement of how much electromagnetic radiation is absorbed by body tissue while using a mobile phone the higher the SAR, the more radiation is absorbed. The concept of SAR has been around for many years and RF safety concerns are not a new development. Most people are aware that a microwave oven can heat tissue such as food by using RF power, and it is this heating effect from mobile phones that causes the most concern from a RF safety point of view. SAR limits are set to protect users from wireless devices that exceed the transmitted RF threshold. In Europe the head SAR limit*, with which all mobile phones on sale in the UK must comply, is 2.0 W/kg** in 10g of tissue. to demonstrate the What manufacturers should be doing compliance of mobile In Europe and the UK, manufacturers that want to place a wireless device onto the European market must meet the requirements of the Radio and Telecommunications Terminal Equipment Directive (R&TTE). It requires the protection of the health and safety of the user and any other person. Manufacturers that make a wireless device, which uses the radio frequency range from 30MHz to 6GHz, must comply. Although the R&TTE Directive will be superseded by the Radio Equipment Directive (RED) in June 2016, the essential requirements are largely identical and the situation as far as SAR is concerned will remain unchanged. phones with the basic restrictions related to human exposure to electromagnetic fields (300 MHz 3 GHz) G EN50566 Product standard to demonstrate compliance of radio frequency fields from handheld and bodymounted wireless What is SAR testing? communication SAR testing determines whether or not a product is compliant. It measures the heating effect on human tissue, to nd out if a wireless communications device meets the requirements for RF exposure. During this process, a probe is positioned at various points within a phantom head or body, which is lled with uid that resembles tissue that matches the dielectric characteristics*** of the human body. To test what heating effect a wireless device, such as a mobile phone, has on a persons head, a 2D/area scan of the phantom head is taken to show the location of the highest SAR the hotspot. A Zoom Scan/3D scan is then carried out to nd the maximum averaged SAR**** for that position. With testing using the head phantom, the highest SAR is not always adjacent to the antenna, as the antenna may be beyond that phantom, but SAR is present where the device comes in contact with the phantom. During testing using a at body phantom, the SAR measurement hotspot is normally next to the devices antenna. However, the declared SAR***** is determined Unknown brands may at the highest operational power level of a device. pose a greater risk and This represents a worst-case scenario because, inspectors are advised to during normal operation, the actual SAR level of the focus on these shipments to ensure device could be well below the maximum value. This that manufacturers new to the EUs is because mobile phones are designed to operate requirements are complying at multiple power levels, so as to use only the power required to communicate effectively with a mobile network. This means that the closer a person is to a mobile phone networks base station, the lower the power output of the mobile, and vice versa. However, as the SAR value is heavily dependent on the location of the antenna in the phone, coupled with the RF output power, it is the manufacturers responsibility to ensure that samples used to measure SAR levels at the compliance phase of development match the nal product that will go into large-scale production and eventually go onto the EU market. devices used by the general public (30 MHz 6 GHz) What should you be looking for? While mobile device manufacturers do not have a legal obligation to inform a user of the products SAR level, the majority include SAR values in either the user manual and/or on their website. Trading standards inspectors and European consumers should be able to nd the two separate body and head SAR ratings, if they look. The use of the CE mark on a product is a declaration by the manufacturer that the product is compliant with the required EU Directive and standards, and thus suitable for sale in the EU. Mobile phones from many well-known and trusted brands are also likely to carry a Notied Body (NB) number after the CE logo, which shows that the product has been independently veried. For example, the certication body TV SD BABT has the NB number 0168. For well-known brands, reputation is vital, and compliance with SAR regulations is paramount to them. This means that we rarely see any such products coming into our laboratories that do not comply. However, with the substantial growth in both mobile technologies and new manufacturing markets coming online, unknown brands may pose a greater risk and inspectors are advised to focus on these shipments to ensure that manufacturers new to the EUs requirements are complying. *A term contained within the European harmonised standard for SAR measurements: 2W/kg in 10g of tissue is the limit for head SAR. In the USA, the limit is lower at 1.6W/kg. **W/kg means watts per kilogram. ***a non-conducting material whose molecules align or polarise under the inuence of applied electric elds, used as an essential component of capacitors. ****The maximum averaged SAR is the maximum amount of radiation that a mobile phone is allowed to emit. *****Mobile phone manufacturers are obliged to declare highest measured SAR in their documentation supplied to the user and in some cases print it on the boxes the mobile phones are supplied in. R ADIO WAVES EXPL AINE D JARGON BUSTER Credits Published You might also like Jean-Louis Evans is managing director of Tuesday 27 January, 2015 Product safety January 2015 TV SD Product Service. To share this page, click on in the toolbar Antenna: Device designed to radiate and receive electromagnetic energy. Feeder: Coaxial cable that connects an antenna to a base station transmitter or receiver. Macrocell: A macrocell provides the main radio coverage infrastructure for a mobile network. The antennas for macrocells are mounted on ground-based masts, rooftops and other existing structures, at a height that provides a clear view over the surrounding buildings and terrain. Macrocells provide radio coverage over varying distances dependent upon frequency capacity and clutter. Macrocell base stations have power outputs of typically tens of watts. Microcell: Microcells provide infill radio coverage and additional capacity where there are high numbers of users within urban and suburban macrocells. The antennas for microcells are mounted at street level (that is, below the surrounding buildings and terrain) typically on the external walls of existing structures, lamp-posts and other street furniture. Microcell antennas are smaller than macrocell antennas and, when mounted on existing structures, can often be disguised as building features. Microcells provide radio coverage over distances, typically, between 300m and 1,000m. Microcell base stations have lower output powers than macrocells, typically a few watts. Mobile phones and their base stations transmit and receive signals using electromagnetic waves, which are also referred to as electromagnetic fields, or radio waves. Electromagnetic waves are emitted by many natural and man-made sources and play a very important part in our lives. For example, we are warmed by the electromagnetic emissions of the sun and we see using the part of the electromagnetic spectrum that our eyes detect as visible light. All electromagnetic radiation consists of oscillating electric and magnetic fields and the frequency the number of times per second at which the wave oscillates determines their properties and the use that can be made of them. Frequencies are measured in hertz or Hz, where 1Hz is one oscillation per second, 1kHz a thousand, 1MHz is a million, and 1GHz is a thousand million. Frequencies between 30kHz and 300GHz are widely used for telecommunication, including broadcast radio and television, and comprise the radio frequency band. In the UK, AM radio uses frequencies between about 180kHz and 1.6MHz, FM radio ranges from 88-108MHz, and television ranges from 470-854MHz. Cellular mobile services operate Picocell: Picocells provide more localised coverage than within the frequency ranges 872-960MHz, 1710-1875MHz and microcells, inside buildings where coverage is poor or there are 1920-2170MHz. Waves at higher frequencies but within the RF high numbers of users. region up to 60GHz are referred to as microwaves and have Radio base station: A base station is a macrocell, microcell or a wide variety of uses. These include radar, telecommunication picocell site and consists of transmitters and receivers in a cabin links, satellite communications, weather observation and or cabinet connected to antennas by feeders. medical diathermy. Source: www.ofcom.org.uk Source: w ww.ofcom.org.uk