Bluetooth 5 in Smartphones

Last February we wrote about the progress of Bluetooth 5 in recent smartphones. A few months on and Nordic Semiconductor, the company that produces the System on a Chip (SoC) used in most beacons, has a new blog post on Bluetooth 5 in Smartphones and how we are about to experience a tipping point in support for Bluetooth 5.

The final observation from the article is:

Even if sticking to previous incarnations of Bluetooth may look like the right choice, the marketing power of Bluetooth 5, regardless of whether it’s needed or not, is likely to help companies differentiate products and increase sales.

This is true. Some companies currently claiming Bluetooth 5 support in products don’t actually use Bluetooth 5 yet but instead offer an upgrade path to Bluetooth 5.

Bluetooth 5 Simultaneous Multiple PHY

If you have been following our posts on Bluetooth 5, you might be wondering how one Bluetooth device can communicate to many devices, some of which might be legancy Bluetooth 4.

There’s a new video from Nordic Semiconductor (who produce the System on a Chip – SoC – inside most beacons) where the new long range mode is used while connecting to up to 20 devices. These can be different PHYs meaning that different capabilities, for example high speed vs long range vs legacy) can be connected at the same time.

Update on Bluetooth 5 and Beacons

It’s nearly a year since we wrote about Bluetooth 5 Beacon Implementation Tradeoffs.

Since then, the Samsung S8, iPhone 8/X, and Google Pixel 2 have been released that support Bluetooth 5. However, while these support the LE 2M high speed PHY they don’t support the longer range PHYs. There are currently no smartphones that can take advantage of Bluetooth 5’s longer range.

There are few true Bluetooth 5 beacons. Most that say they are Bluetooth 5 ‘ready’ or ‘compatible’ are only compatible to the extent that their firmware can be upgraded in the future.

An exception is SNCF, the French train company, who are manufacturing their own beacons in order to start experimenting with Bluetooth 5. As mentioned in the Mr Beacon video, SNCF are looking to Bluetooth 5 to provide for (up to x4) better beacon battery life. How is this possible, especially as the SoC chips themselves (usually nRF52 or TI CC2640) are the same whether they run Bluetooth 4 or 5? The battery current is actually the same. Bluetooth LE devices consume most power when actually transmitting and negligible power inbetween transmissions. The faster data rate allows the Bluetooth device to transmit the same data over less time thus using less battery power.

Bluetooth 5 Advertising Extensions

There’s an interesting new article on the Nordic Blogs on Bluetooth 5 Advertising Extensions . It explains how the number of channels is increasing, from 3 in Bluetooth 4.0, allowing larger advertising payloads in one of the 37 other data channels. A single advertising packet can hold up to 255 bytes of data, up from 37 in Bluetooth 4.0. The chaining of packets allows for larger payloads up to 1650 bytes.

As the article mentions, we have to wait until tablets and smartphones support Bluetooth 5. Also, we have to wait for new Beacons with Bluetooth 5.

Mouser ezine – Understanding Bluetooth 5 and Mesh

Mouser has a free ezine called ‘Methods’ (pdf) that has in-depth articles on the latest advances in Bluetooth.

Steven Hegenderfer, Director of Developer Programs at Bluetooth SIG explains how Bluetooth 5 will enable design engineers to pioneer innovative solutions. Steven Keeping shows how Bluetooth has evolved and Barry Manz explains Bluetooth Mesh Networking and beacons.

Read more about Bluetooth mesh on our web site.

Latest Nordic Wireless Quarter Magazine Available

Beacons are small computers with a complete System on a Chip (SoC). There are four main companies that manufacturer SoCs: TI, Dialog, NXP and Nordic. Nordic is the most popular SoC for use in beacons, mainly because of the lower (tool) license cost and ease for beacon manufacturers developing the software (actually called firmware) that runs in the beacons.

Nordic has a new free Wireless Quarter Magazine that showcases uses of Nordic SoCs in many types of device, not just beacons.

The magazine also has articles on how Nordic is the first to launch a Bluetooth mesh Software Development Kit, how Mesh strengthens Bluetooth wireless’ IoT credentials and explains Bluetooth 5’s advertising extensions. The article says of Bluetooth 5’s advertising extensions:

“Advertising extensions, periodic advertisements, and connectionless broadcast will have a major impact on beacons”

However, the article says:

“This won’t happen overnight because few current smartphones incorporate Bluetooth 5, but expect beacons to proliferate over the next several years as new smartphones are rolled out”

Analysing the Bluetooth LE 2.4GHz Spectrum

In most cases you can place your beacons and they ‘just work’. However, what if you suspect things aren’t working due to other devices using the same 2.4GHz radio spectrum? It’s possible to use specialist test equipment and spectrum analysers but these are very expensive.

A new, recent article by Mark Hughes describes Troubleshooting Tools for Your Next Bluetooth LE Project: Ubertooth and the Nordic nRF Sniffer.

It shows how to use inexpensive dongles on Mac, Linux, and Windows to intercept and analyse Bluetooth LE packets.

Nordic Releases nRF52810

Nordic, who supply the System On a Chip (SoC) in many beacons, have recently released the nRF52810 SoC.

Nordic already offer the nRF52840 and nRF52832 but while these have been suitable for use in Bluetooth 5 beacons they are over-specified and hence too expensive for use in most beacons. The nRF52810 solves this problem by providing a reduced feature set that makes this SoC typically 25% less expensive. Nordic say:

“The nRF52810 represents the most accessible, single-chip Bluetooth 5 solution available on the market today.”

A post on the Nordic devzone explains the main differences between the nRF52810 and nRF52832. It’s mainly removal NFC and other peripherals that aren’t important for beacons.

The nRF52810 supports Bluetooth 5 high speed and advertising extensions but, interestingly, not long range. It’s expected that the removal of the redundant peripherals should also improve power and hence battery use.

Android O Bluetooth 5 Device API Observations

Last March we took a closer look at Bluetooth 5 and concluded there are tradeoffs between long range, high speed, legacy (today’s) phone compatibility and efficient battery.

We are starting to see corresponding development APIs appear for devices that will detect Bluetooth 5 beacons. Android (O) has a new setPreferredPhy call that allows apps to choose the PHY modes mentioned in our previous article.

As expected, high speed and long range are mutually exclusive and if you want to remain compatible with older (current) beacons then you can’t have the high speed or long range. Long range and high speed are only supported if the hardware supports it which means old (current) smartphones won’t get Bluetooth 5 support through a software upgrade.

The availability of the Android API raises new questions. Our understanding is that PHY is a low level thing and that the Bluetooth hardware can only work in one PHY mode at a time. If so, what if an app changes the PHY? Does this switch for all apps? What are implications? For example, what if one app, for example an existing app, needs to use older beacons in compatibility mode while another app wants to use Bluetooth 5 long range beacons? Maybe we are wrong and the underlying Bluetooth 5 firmware somehow multi-tasks PHY modes? Finally, how does the app know the device is Bluetooth 5 capable? It remains to be seen how the fragmentation of capability and behaviour is going to be workable on a typical app. Will most apps end up defaulting to compatibility mode, the long range and high speed only being used for special cases (devices)? In any case, we can see it’s likely that Bluetooth 5 is going to complicate beacon app development.

28/6 UPDATE: In response to this post, Martin Woolley of the Bluetooth SIG answered all our questions! Hardware, hence Android O, can have several PHY modes active at the same time provided the underlying device supports this.

The Use of Beacons in Smart Cities

There’s a recent paper by Gonzalo Cerruela García, Irene Luque Ruiz, and Miguel Ángel Gómez-Nieto of the University of Córdoba, Spain on State of the Art, Trends and Future of Bluetooth Low Energy, Near Field Communication and Visible Light Communication in the Development of Smart Cities (pdf)

The paper explains how technologies (NFC, BLE, VLC) will be important for the Internet of Things in smart cities and how they will need to be connected via LoRaWAN, Sigfox, Weightless, LTE, and 5G. With regard to Bluetooth LE they say:

Another challenge for the attention of BLE technology is the limited range problem; the range is directly dependent on Broadcasting Signal Power. An increase in signal power makes BLE devices less energy-efficient. Moreover it is necessary to improve accuracy in determining proximity to a BLE device.

The range problem will become less of an issue once Bluetooth 5 devices become available.