Small cells and EME
What are small cells?
Small cells are low-powered radio transmitters for mobile phone services. Their small size makes them more discreet. Telstra uses small cells to improve coverage, connectivity, and customer mobile experience without the need to build as many big mobile towers.
Small cells are not new. We’ve used them in our cities and suburbs since the 2G era nearly 30 years ago. They also enhance mobile coverage in regional and rural areas. Telstra is now investing in the latest generation of 4G and 5G small cell technology to provide even better mobile coverage and connectivity for our customers in high traffic areas.
Small cells use low power levels and are designed to comply with Australia’s mandatory electromagnetic energy (EME) safety standards. Our testing shows that EME levels near small cells are very low – far below the EME safety limits, which themselves have a significant safety margin built in.
What are their benefits
As well as being discreet due to their small size, small cells also offer the possibility of improved coverage and greater capacity.
Small cells provide a coverage boost in areas where the existing mobile signal is weaker. This could include hilly areas or suburban and city streets where buildings and trees reduce mobile reception, or regional towns and communities.
Small cells allow our network to carry more data and phone calls in very busy areas where there are many people using mobile devices. Telstra's new 4G and 5G small cells add the equivalent of 'extra lanes' on a busy road to provide a boost in capacity.
Small cell at Barwon Heads
Video content description
A video showing EME testing of a small cell on an electricity pole giving additional coverage and extra channels for mobile traffic in the busy seaside town of Barwon Heads.
Footage: Mike Wood and Lucinda from Telstra standing on a footpath in front of a power pole, holding a mobile phone and a spectrum analyser.
Audio – Mike: Hi, it's Mike Wood here from Telstra and I'm with Lucinda and we're down at Barwon Heads on the beautiful Bellerine Peninsula.
Footage: Summer scenes including a beach and a pier.
Audio – Mike: It's a seaside resort in southern Australia. There's lots of activity over summer with people swimming, canoeing in the river and camping.
00:18 The small cell installation
Footage: Cuts back to Mike and Lucinda.
Audio – Mike: And to give that extra capacity and extra coverage boost, we've installed a small cell and it's on the electricity pole. Hamish, if you can zoom in to the three antennas that are halfway up the pole.
Footage: Camera zooms towards the small cell on the electricity pole, before going back to a wide shot of Mike and Lucinda.
Audio – Mike: There's three really small antennas and that's providing a 4G and a 5G coverage and capacity boost to this area. I'm going to show you what that means in practical terms.
00:35 5G signal strength
Footage: Zooms into the mobile phone screen, showing the 5G signal strength at four bars.
Audio – Mike: So if you want to come in and look at my phone. I've got full-strength 5G, so there's four bars of 5G on my phone and that's because we've got the small cell there. With the small cell switched off there would be about two signal bars, so the coverage would be a little bit less with the small cell off.
00:55 Spectrum analyser and EME measurement
Footage: Pans across to the screen of the spectrum analyser.
Audio – Mike: I'll show you what that means in terms of the spectrum analyser. So, we've got a spectrum analyser here showing the two radio frequency signals at 2600 MHz. Now there's two channels here, both giving 4G and 5G coverage and capacity. Now this is like two extra lanes on a busy road so, particularly over summer when you've got a lot of people using the network, these two extra lanes provide that additional capacity.
Footage: Zooms in to the signal average, showing 0.020%.
Audio – Mike: And in terms of EME, we're measuring the radio frequency levels and in the top right-hand corner, we're measuring a signal of… the average is 0.02%. Now that's well over a thousand times below the public safety limit.
Footage: Zooms back out to the wide shot of Mike and Lucinda.
Audio – Mike: So in summary, the small cell here is giving a great coverage boost - you can see the boost on the phone before. We've got the two extra channels giving the capacity boost for this area, and we've got very low EME levels. They're the benefits of small cells.
Small cells safety
Small cells use low power levels and comply with Australia's mandatory EME safety standards, which themselves have a significant safety margin built in.
The Australian Communications and Media Authority (ACMA) has conducted measurements near small cells to verify compliance and found that, for all small cell sites measured, the levels of EME emissions in publicly accessible areas are very low (less than 1 per cent) compared to the Australian Standard for EME emissions.
The Australian EME safety standards:
- are very conservative and include large safety margins
- protect all people (including children) from radiofrequency EME
- cover the frequencies in the frequency range 100 kHz to 300 GHz including mmWave bands and other frequencies used for 5Gs.
Read more about ARPANSA EME Safety Standards.
Small cell EME testing
We undertake regular and rigorous EME testing of our small cells to ensure the safety of our small cells and the community.
Recently, we reached out to communities and residents living near our small cells to offer testing of EME levels inside and near their homes and carried out testing in requested areas.
Testing showed that outdoor EME levels from the small cells were over 1000 times below the safety limit and even less than this inside homes. Small cell EME levels inside homes were similar to those from Wi-Fi.
Our three key findings from the small cell EME measurements in an around residential homes are as follows:
- EME levels were consistently over 1000 times below the public safety limits – both outdoors and indoors.
- EME levels inside homes were substantially lower than outside.
- EME levels inside homes from the small cells were low, and similar to Wi-Fi.
We’ve done extensive EME testing around Telstra’s 4G small cell installations, using independent accredited EME assessors.
Our testing program has included small cells in metropolitan areas providing extra mobile coverage and capacity to local homes and businesses. Our independent testing shows EME levels that are less than 0.2% of the EME safety limits – more than 500 times below the mandatory safe levels. Standing directly under a small cell on a streetlight pole produced the same result of less than 0.2% of the EME safety limits.
Even when a small cell is loaded with traffic in a busy area, EME levels are still very low and far within EME safety limits. We tested a 4G small cell installed in a conference centre, and even at a close distance of two metres from the small cell itself, EME levels were more than 50 times below safe EME limits.
We have also conducted EME testing on 4G small cells in a rural town where we found the EME levels from the small cell to be very low, less than 0.0001% of the public safety limit and similar to the Wi-Fi from the general store.
During 2020 and 2021, Telstra conducted a 5G mmWave small cell trial in Melbourne, Sydney, Brisbane, and the Gold Coast using a scientific licence from the Australian Communications and Media Authority.
As part of the trial we conducted extensive 5G mmWave small cell EME testing at over 50 locations in real world settings including café’s, playing fields, residential streets, apartments, homes, schools, child care centres, metropolitan shopping precincts, CBD’s, public transport hubs, and our own laboratory and demonstration centres.
To conduct the EME tests we loaded the small cells with a downlink data rate ranging from 1.8 – 2.3 Gbps to a mobile device. This ensured the small cells were operating at a very high capacity.
Our testing results show the EME levels in the general environment from the 5G small cells to be very low less than 1% of the EME safety limits and ranged from 0.28 to 0.0005 % of the public safety limit. In most cases the 5G small cells produced EME levels over 1000 times lower than the public safety limit even under high activity.
Telstra’s new 5G mmWave small cells use advanced antenna technology including beamforming to better direct signals to a user’s device while minimising interference from other users thereby achieving high upload and download data rates. This also helps to minimize EME levels.
5G small cell testing locations
The photos below show a sample of locations in the South Brisbane trial where the 5G small cell EME testing was conducted.