Short Range Wireless
Bluetooth Low Energy, WiFi 6 and the future of IOT
By Dr Nick Wood, director, sales & marketing, Insight SiP B
luetooth Low Energy is arguably the technology that “launched” the Internet of Things. The issue with “classic” Bluetooth was that it needed a continuous connection, which in turn meant it had rather limited battery life, and thus battery powered devices required frequent recharging. It also limited the use cases for which it could be easily deployed. Bluetooth Low Energy fixed these issues by putting devices to sleep between transmissions whilst maintaining their connection. It also allows easy ad-hoc pairing. Alongside various other technical enhancements, this enabled the deployment of a large number of low power devices, sharing relatively modest amounts of data, but in the process vastly enhancing widespread connectivity. The trend of WiFi has been in a different direction up till now – mainly focused on ever faster data rates to allow for high-definition content streaming and serving the needs of “cloud” based computing. Power consumption hasn’t been a major consideration and issues around spectrum not the main concern either. The target market was a relatively small number of big powerful devices sending a lot of data around.
You could say that WiFi was like the sledgehammer and Bluetooth Low Energy the scalpel – different tools for different jobs.
New Bluetooth developments However, new developments in both technologies are starting to take them in converging directions. On the Bluetooth side, the data rate increased with the version 4.2 and version 5.2 introduced streaming
capabilities for audio, alongside a new CODEC. This isn’t quite High-Definition video but it takes Bluetooth Low Energy away from its IOT data-based roots.
WiFi 6 brings new capabilities On the WiFi side, WiFi 6 is a development aimed squarely at improving WiFi’s capabilities for IOT solutions. As mentioned above, previous iterations of WiFi were all about speed. This has been achieved by wide band channels. The flip side of this is that there can’t be very many of them in the limited spectrum allocated for free-to-air
use. This doesn’t matter so much if one or two users are streaming from a home router, but as anyone who has used a public WiFi service in a busy area will know, networks can easily get saturated.
WiFi6 therefore borrows a few tricks from the cellular world and splits up the spectrum into sub-carriers, that allows for a larger number of users to transmit simultaneously, albeit at a lower data rate. These can be quite flexibly used, so different users can be allocated different numbers of resource units across the same time period, depending on need. A further enhancement is the
implementation of “Target Wake Time” – whereby devices can request to wake up again after a defined time interval and drop into sleep mode in between. This is very much aimed at reducing the minimum level of power consumption required for a WiFi device.
46 November 2022 Components in Electronics
To further enhance the capabilities of WiFi in dense environments, MiMo antennas are included at both ends of a connection, to allow spatial network sharing. Additional features enable overlapping networks with weak signals to be ignored.
Crossover
All this pushes WiFi firmly into the IOT domain – dense networks, flexible data usage, allowing battery powered devices using limited amounts of data – all of this sounds pretty much like the pitch that Bluetooth Low Energy made 10 years ago.
Bluetooth Low Energy & WiFi 6 – competitors?
So, what does it add up to? Are these technologies now “competitors” where one will “win” and the other “lose”? Not quite, I think. There is clearly some
www.cieonline.co.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62
