Modern smartphones and other devices are touting support for "Bluetooth 5.0" on their specification sheet. Here's what's new in the latest and greatest Bluetooth.

What is Bluetooth?

Bluetooth 5.0 is the latest version of the Bluetooth wireless standard. It is commonly used for wireless headphones and other audio equipment, as well as wireless keyboards, mice, and game controllers. Bluetooth is also used for communication between various smart home and Internet of Things (IoT) devices.

The new version of the Bluetooth standard means various improvements, but only when used with compatible peripherals. In other words, you won't see any benefit from upgrading your Bluetooth 5.0 phone if all of your Bluetooth accessories have been designed for an older version of Bluetooth. However, Bluetooth is backward compatible, so you can continue to use existing Bluetooth 4.2 and older devices with your Bluetooth 5.0 phone. And when you buy new Bluetooth 5.0 peripherals, they will work better with your Bluetooth 5.0 phone.

Low power consumption Bluetooth wireless headphones (and more)

It is important to note that all Bluetooth enhancements are related to the Bluetooth Low Energy specification, which was introduced with Bluetooth 4.0, and not to the classic Bluetooth radio, which uses more power. Bluetooth Low Energy technology is designed to reduce the power consumption of Bluetooth peripherals. It was originally used for carriers, beacons, and other low-power devices, but had some serious limitations.

For example, wireless headphones couldn't communicate via Bluetooth Low Energy, so they had to use the more powerful Bluetooth voice standard instead. With Bluetooth 5.0, all audio devices communicate using Bluetooth Low Energy, which means lower power consumption and longer battery life. In the future, many other types of devices will be able to communicate with Bluetooth Low Energy.

Notably, Apple's AirPods don't use Bluetooth 5.0. They use Bluetooth 4.2 and a dedicated Apple W1 chip to improve connectivity. On Android, Bluetooth 5.0 should help make Bluetooth headphones something you want to use.

Dual Audio

Bluetooth 5.0 also provides a great new feature to play audio on two connected devices at the same time. In other words, you can have two pairs of wireless earbuds connected to your phone, and they simultaneously transmit audio to both of them via standard Bluetooth. Or you can play audio on two different speakers in different rooms. You could stream two different audio sources at the same time to two different audio devices at the same time, so two people could listen to two different pieces of music, but they would be streamed from the same phone.

This feature is called "Dual Audio" on the Samsung Galaxy S8. Just connect two Bluetooth audio devices to your phone, enable Dual Audio and you're ready to go. However, this shouldn't be a Samsung feature. It has Bluetooth 5.0 enabled and will hopefully appear on other manufacturers' devices.

More speed, distance and bandwidth

The main advantages of Bluetooth 5.0 are improved speed and greater range. In other words, it is faster and can operate over longer distances than older versions of Bluetooth.

When will you receive it?

You can get Bluetooth 5.0 enabled devices today, such as the iPhone 8 and 8 Plus, iPhone X, Samsung Galaxy S8 and S9, and future Android phones. However, you also need Bluetooth 5.0. They are not yet widespread, but many manufacturers are promising to release Bluetooth 5.0 devices in 2018.

Since Bluetooth is backward compatible, your Bluetooth 5.0 and older Bluetooth devices will work together. It's a bit like moving to a new, faster Wi-Fi standard. Even after you get a new router that supports faster Wi-Fi, you also need to update all other devices. But your older Wi-Fi enabled devices can still connect to your new router at a slower speed than the router supports.

If you can access a Bluetooth 5.0 Android phone and Bluetooth 5.0 headphones, you are likely to have much better wireless sound than the old Bluetooth standard.

IPhone users can get a good experience with Apple's own AirPods or Beats thanks to the W1 chip, but now get good Bluetooth audio on Android. Bluetooth 5.0 should even improve on wireless headphones on the iPhone if you decide to upgrade to third-party Bluetooth 5.0 headphones instead of Apple's W1-based headphones.

However, we do not recommend updating every little thing. Even if you have a laptop with Bluetooth 5.0 support, for example, upgrading your mouse to Bluetooth 5.0 probably won't be a big improvement. But as Bluetooth 5.0 support is reflected in every new Bluetooth device, Bluetooth peripherals will get better and Bluetooth will become more reliable and energy efficient.

Hello.

On December 3, 2014, the Bluetooth SIG officially announced the bluetooth specification version 4.2.
The press release lists 3 main innovations:

• increase in the speed of data transmission and reception;
• the ability to connect to the Internet;
• improving privacy and security.

The main thesis of the press release: version 4.2 - ideal for the Internet of Things (IoT).
In this article, I want to tell you how these 3 points are implemented. Who cares welcome.

Everything described below applies only to BLE, let's go ...

1. Increasing the speed of receiving and transmitting user data.

The main disadvantage of BLE was its low data transfer rate. Although from which side to look, after all, BLE was originally invented for the sake of saving the energy of the source that powers the device. And in order to save energy, you need to intermittently get in touch and transfer some data. However, all the same, the entire Internet is filled with indignation about low speed and questions about the possibility of increasing it, as well as increasing the size of the transmitted data.

And now with the advent of version 4.2, Bluetooth SIG announced an increase in the transmission speed by 2.5 times and the size of the transmitted packet by 10 times. How did they achieve this?

I will tell you that these 2 numbers are related to each other, namely: the speed increased because the size of the transmitted packet increased.

Let's look at the PDU (protocol data unit) of the data channel:


Each PDU contains a 16-bit header. So, this title in version 4.2 differs from the title in version 4.1.

Here is the title of version 4.1:

And here is the title of version 4.2:

Note: RFU (Reserved for Future Use) - the field designated by this abbreviation is reserved for future use and is filled with zeros.

As we can see, the last 8 bits of the header are different. The "Lenght" field is the sum of the lengths of the payload and the MIC (Message Integrity Check) field in the PDU (if enabled).
If in version 4.1 the "Lenght" field has a size of 5 bits, then in version 4.2 this field is 8 bits in size.

From here it is easy to calculate that the "Lenght" field in version 4.1 can contain values ​​in the range from 0 to 31, and in version 4.2 in the range from 0 to 255. If we subtract the length of the MIC field (4 octets) from the maximum values, we get that the payload can be 27 and 251 octets for version 4.1 and 4.2, respectively. In fact, the maximum amount of data is even less, since the payload also contains the L2CAP service data (4 octets) and ATT (3 octets), but we will not consider this.

Thus, the size of the transmitted user data has increased approximately 10 times. As for the speed, which, for some reason, increased by 10 times, and only 2.5 times, then we cannot talk about a proportional increase, because everything also depends on the guaranteed delivery of data, because it is a little more difficult to guarantee delivery of 200 bytes than 20.

2. Ability to connect to the Internet.

Perhaps the most interesting innovation is why the Bluetooth SIG announced that version 4.2 makes the Internet of Things (IoT) better because of this feature.

Back in version 4.1, the "LE Credit Based Flow Control Mode" appeared in L2CAP. This mode allows you to control the data flow using the so-called. credit based scheme. The peculiarity of the scheme is that it does not use signal packets to indicate the amount of transmitted data, but asks another device for a loan for a certain amount of data for transmission, thereby speeding up the transmission process. At the same time, the receiving side each time it receives a frame, decreases the frame counter, and when the last frame is reached, it can terminate the connection.

3 new codes have appeared in the list of L2CAP commands:
- LE Credit Based Connection request - request for connection under the credit scheme;
- LE Credit Based Connection response - a response to a connection under a credit scheme;
- LE Flow Control Credit - message about the possibility to receive additional LE-frames.

In the package "LE Credit Based Connection request"


there is a 2 octet "Initial Credits" field indicating the number of LE frames the device can send at the L2CAP level.

In the response package "LE Credit Based Connection response"


the same field contains the number of LE-frames that another device can send, and the "Result" field also contains the result of the connection request. A value of 0x0000 indicates success, other values ​​indicate an error. In particular, a value of 0x0004 indicates a connection failure due to lack of resources.

Thus, already in version 4.1, it became possible to transfer a large amount of data at the L2CAP level.
And now, almost simultaneously with the release of version 4.2, the following is published:

• service: "IP Support Service" (IPSS).
• Internet Protocol Support Profile (IPSP), which defines support for the transfer of IPv6 packets between BLE-enabled devices.

The main profile requirement for the L2CAP level is the "LE Credit Based Connection", which appeared in version 4.1, which, in turn, allows you to transfer packets with MTU> = 1280 octets (I hope the hint at the figure is clear).

The profile defines the following roles:
- Router role — used for devices that can route IPv6 packets;
- node role (Node) - used for devices that can only receive or send IPv6 packets; have a service discovery function and have an IPSS service that allows routers to discover a given device;

Router-role devices that need to connect to another router can have the host role.

Oddly enough, but the transmission of IPv6 packets is not part of the profile specification, and is specified in the IETF RFC "Transmission of IPv6 packets over Bluetooth Low Energy". This document identifies another interesting point, namely, that when IPv6 packets are transmitted, the 6LoWPAN standard is used - this is a standard for interworking using the IPv6 protocol over low-power wireless personal networks of the IEE 802.15.4 standard.

Take a look at the picture:


The profile specifies that IPSS, GATT and ATT are used only for service discovery, and GAP is used only for device discovery and connection establishment.

But the one highlighted in red just means that the transmission of packets is not included in the profile specification. This allows the programmer to write their own packet transfer implementation.

3. Improving privacy and security.

One of the responsibilities of the Sequrity manager (SM) is to pair the two devices. The pairing process generates keys that are then used to encrypt communications. The pairing process consists of 3 phases:

• exchange of information on the methods of pairing;
• generation of short-term keys (Short Term Key (STK));
• key exchange.

In version 4.2, the 2nd phase was divided into 2 parts:

• generation of short-term keys (Short Term Key (STK)) called "LE legacy pairing"
• generation of long-term keys (Long Term Key (LTK)) called "LE Secure Connections"

In this regard, in addition to the 3 existing functions, in the cryptographic toolbox of the security manager, 5 more appeared and these 5 are used only to service the new LE Secure Connections pairing process. These functions generate:

• LTK and MacKey;
• confirming variables;
• authentication check variables;
• 6-digit numbers used for display on linked devices.

All functions use the AES-CMAC encryption algorithm with a 128-bit key.

So, if 2 keys were generated during pairing in the 2nd phase using the "LE legacy pairing" method:

• Temporary Key (TK): a 128-bit temporary key used to generate the STK;
• Short Term Key (STK): A 128-bit temporary key used to encrypt the connection

then 1 key is generated using the LE Secure Connections method:

• Long Term Key (LTK): A 128-bit key used to encrypt subsequent connections.

As a result of this innovation, we got:

• preventing tracking because now due to "Numeric Comparison" it is possible to control the ability to connect to your device.
• improved energy efficiency, as no additional energy is now required to re-generate keys on every connection.
• Industry standard encryption for securing sensitive data.

Oddly enough it sounds, but due to improved safety, we got an improvement in energy efficiency.

4. Is there already an opportunity to feel it?

Yes, I have.
NORDIC Semiconductor has released the "nRF51 IoT SDK" which includes the stack, libraries, examples and APIs for the nRF51 series devices. This includes:

• chips nRF51822 and nRF51422;
• nRF51 DK;
• nRF51 Dongle;
• nRF51822 EK.

Review of fully wireless headphones Syllable D900P on Bluetooth v5.0, comparing them with another TWS-16, as well as recommendations for choosing and buying headphones of this type.
In short: I was completely satisfied with the purchase ...

5.1 Communication - Bluetooth 5.0

5.2 Sound

6. Conclusions

1. Introduction

The task before me was to buy myself Bluetooth headphones. The main criteria were:
1. Complete wireless
2. The presence of a case for carrying and charging
3. Small size and weight
4. Price / quality (20 ~ 30 $)
There is a huge list of criteria and differences when choosing such headphones. In the review, I will try to tell you about these differences, as well as what you should pay attention to when choosing them.

My first attempt was to buy headphones:
At that time, there was a discount on them, and bribed a record low weight, only 3.5 grams (each earphone).
But the first pancake, as they say, is lumpy. Opening the package, one earphone was not found in it.
I thought it was a joke, or I didn't see anything in the description, but no. Therefore, in the course of the review, I will compare both models (although this cannot be called a full-fledged comparison), paying attention to the very differences and their importance when choosing.

P.S. Having contacted those support, they offered me a refund of $ 10, and of course I should keep the earphone for myself. I'm not one of those people who like to cheat, or profit from sellers. It can be used as a bluetooth headset, or for listening to music, but still it is alone. I could not sell it, so the amount of $ 10 will not be enough for me to buy new headphones, and I will not be able to fully listen to music either. Consequently, I requested a full refund, explaining my position, and they agreed.

While I was waiting for a refund, I had time to think about buying new ones. Buy the same ones, while keeping the left earphone and charging case in stock, or choose another model.
Realizing what I was missing, and what I would like to improve, I set about searching.
The Internet is full of a variety of models, both branded. But often the same headphones can be found under different brands. Therefore, you should be careful. Thinking that you are buying "branded" headphones, you are purchasing an unnamed product, but under the logo of one of the brands. As a rule, such "brands" are little known, and if you find something new and interesting, take the time to study in more detail. Perhaps you will find exactly the same headphones, but under a different new and interesting name. And in the end, without any mention of the company at all, and besides, it is cheaper.
I narrowed my choice down to two models, the first one, the reviews of which are on this site, and the Internet is simply teeming with them:
1. TWS Touch Two JH-S9100 :,
The second was something new:
2.
The first model completely suited me, both the price and the parameters. But the second bribed, though little-known, but the brand () and the presence.
This model is a novelty of 2018, and there are practically no reviews on it. Only a couple of reviews that carry little useful information. But while I was waiting for the package, the amount of information kept growing, and these were laudatory comments, which cannot but rejoice.

2. Packing & picking

Such a simple detail as a complete set is still worth paying attention to. In the first TWS-16 model, in addition to the earphone and case, only a cable and instructions were included, there were no additional ones. For me this is not a problem, there are enough spare houses, but! Firstly, not all people have spare ones at home, and secondly, some headphones have a special shape, and apart from relatives, the rest do not fit them.
But Syllable D900P was not greedy for spare ear pads, but this is where all the differences between the bundles end.


Left TWS-16, Right Syllable D900P

3. Appearance

3.1 Charging case

The presence of a charging case in fully wireless headphones is already a plus, in terms of convenience and price, respectively. There are headphones that charge directly from the wire, but they are bulkier and heavier.
Next, you need to decide whether you need the case only for charging, or for transportation. Since not all of them have a protective cover, and can only act as a so-called base. Example:
If you expect to carry headphones in a case, then there are many forms of it.
Without lid, but magnetic and transportable, such as:. By the way, this modification of the headphones exists without a case, but with charging directly from the wire. The difference in price is ~ $ 8.
As for me, this is not a very convenient option, but these headphones are very popular for a long operating time, and a capacious battery, both of the headphones themselves and of the case, which played a role in the overall dimensions.
Quote from him on these headphones:

If you shake the station a little, the earpiece falls out, so it is better to wear this design in a tied complete bag (well, you get the idea).

There are also retractable ones: or
I cannot judge their practicality, but as for me, quite interesting options.

Coming back to the subject of the review, a standard cover is used here. But not on latches, as in most cases, but on magnets. I think this option is much more convenient. You do not need to press any buttons to open the lid, nothing will break, and it will not stick over time. The strength of the magnets is sufficient to avoid accidental discoveries, but I would like twenty percent more powerful.


Inside we see a button that is responsible for turning on / off charging the headphones, as well as turning them on separately, but more on that later. A similar implementation with a magnetic cover and a touch button can be seen in:, but despite the requirement to double-tap to turn on, the external sensor raises concerns about accidental clicks.
In the places intended for charging the headphones, there are magnets that allow them to be well fixed and prevent them from falling out. TWS-16 does not have such happiness, and fixation, as well as full contact for charging, occurs only when the lid is closed. This is another plus for the Syllable D900P.
But what is missing is an indication of the percentage of charge of the case itself. I don't quite understand the absence of such a small but important detail.
As a result, the case turned out to be very convenient and useful, with a set of everything you need for comfortable use, except for the lack of indication of the battery status.






Case weight without headphones: 42g.

For comparison, a little photo of TWS-16, I hide it under the spoiler.

If we compare both cases, then the TWS-16 turned out to be smaller in size, and as for me it is more convenient, but for the sake of functionality this can be sacrificed. Since the Syllable D900P has a large battery, magnets, a power button, and recesses for the headphones allow you to fix them with different sizes of ear pads, while the competitor only fits in the standard small size. If you change the ear cushion to a larger one, then the earphone simply won't fit.

3.2 Headphones

If the case is just an add-on, then the headphones themselves are the main "player" with which you will have to spend a lot of time, and accordingly, their choice should be taken more seriously.
Form and type.
Starting from parodies, which are much more, worse, and indeed there is no need. (Example:). Basically they are all similar, but each manufacturer claims that they have found the perfect shape that will adhere perfectly to your ears. If not, there are many options with ear hooks, which give more fixation, but also additional pressure on the auricle, keep this in mind. Examples:,. For those for whom ordinary hooks are not enough, and an active style of use is meant, there are completely wireless options with earhooks similar to bluetooth headsets: (By the way, also on bluetooth v5.0).


Everything is standard, two charging pads, left / right markings, indicators.
Control... We decided on the mount in the ears, then we need to somehow manage all this. Switch tracks, it is possible to answer calls, and of course turn on and off the device itself. Everything is simple here, control is either mechanical, the button is located on the earpiece itself, or touch.
It's up to you to decide which method is more convenient, but I have a few doubts about touch controls. These are accidental presses while attaching the earphone to the ear (I met a similar problem in the comments), as well as the behavior of the sensor in the cold, or with wet / sweaty hands. Accordingly, for me, the button is more acceptable, although I rarely use it. The player is controlled mainly either through a watch or through a smartphone. The headphones are turned on either by pressing the buttons, or, while on charge, when taken out of the case, they automatically turn on and mate with each other. Very convenient and no need to press anything. As for pairing with each other: in this type of headphone (not only in this model), one headphone is the main one, to which the second headphone is connected, and the signal is transmitted from one headphone to another. The Syllable D900P is dominated by the left side. When turned on (it does not matter, from the button or after taking it off the charge), they automatically mate with each other and carry out a roll call. Something like this: Power on -> Left channel -> Right channel -> Connected -> Pairing. That is, they always automatically go into pairing mode, but if you do not manually connect to them within 15 seconds, they will connect to the previously paired device. In simple words, when turned on, they are paired with the phone after 15 seconds, or you can manually connect to them, speeding up the process. A bit strange logic, but you get used to it quickly. Turning off is also very interesting: you only need to hold down the button on one of the headphones, and they understand themselves, and both are turned off.
But I noticed one oddity, when connected to a phone, they always tell me: second device connected, but when connected to a laptop, watch, or other phones, I hear this every other time. That is, sometimes they perceive something as a second device, but sometimes they do not, but my phone is always called the second device. Tried to reconnect many times without success. Doesn't affect work, just infuriates.

The weight of each earphone is ~ 4.5gr. Since I have scales with a step of 1g, they show the weight of the earphone either 4 or 5. But, in total, both headphones are stable at 9g.
With regards to the fit in the ears, everything is fine here. Although vacuum headphones are not really mine, my fears were in vain. Correctly matched ear pads, and no problem. Brisk walking, head banging, gum chewing, treadmill, all tests passed. With regards to those who are afraid of losing such headphones - complete nonsense. Of course, it can fall out, the situations are different, I did not fix it well, my ears were sweating. But in order not to feel it, you need to have a complete lack of head sensitivity. Well, there are no such headphones, the presence and absence of which is not felt at all.


Compared to TWS-16 (pictured below middle), Syllable D900P is slightly larger, and accordingly by 1gr. heavier

I have no complaints about the headphones. Light weight and good fit are key.

4. Battery

The manufacturer claims the presence of 400mAh in the case and the possibility of 3 additional recharges. Judging by the measurements, this is how it is:


The capacity of the headphones themselves is unlikely to be measured correctly, and for nothing.
At full volume, the headphones lost: 3h 40min. !! I think this is a great result! Since the average operating time of similar ones is mostly 2-2.5 hours.


The competitor played: 2 hours, but it should be taken into account that in this case he was alone. And two headphones consume more, since you need to transmit a signal. Accordingly, the right earbud charges a little faster.

5. Sound - communication (Bluetooth 5.0)

5.1 Communication - Bluetooth 5.0

I contacted several sellers on Aliexpress regarding the availability of Bluetooth 5.0. Two of them replied that they had no idea about the versions, wrote what they were told, and two more (one of which is an official store) assured that there was indeed a fifth version. There is no mention of this model yet, but there is a link to their store in, where this model is already listed.
For me this was an important criterion, so this is one of the reasons why I chose this model. In case of cheating, I think I would return some of the money.
I found an article on the Internet on how to find out the version of a bluetooth device: (Link only for)
And to be honest, with little faith, I was pleasantly surprised, they did not deceive:


In the LMP Version field, we see the coveted inscription 5.0.
Why was version 5 so important for me? The fact is that this type of headphone (any model) does not keep the connection with the phone so well. This is due to their small size, and how they are generally arranged (one earpiece sends a signal to the other ...). I have had the problem of interrupting the connection even with bluetooth headsets, and no big obstacles are needed. Put the phone in the opposite pocket, or cover it with your palms. This is fine! I also hoped for a longer range, because this is written in the specification. But to the seller's question: why is only 10m indicated, is this the 5th version? Nobody knows anything. Plus, the data transfer rate should be higher, and the energy consumption should be less. Well, on top of all this - because I want to!
So, with regards to communication, I can say that everything suits me. Carrying your phone in your pocket or laptop bag is not a hindrance. If the phone is in the opposite pocket (from the main earpiece), then occasionally you can catch an interruption. But even here they are arranged very interestingly, interruptions do not occur abruptly, but as if someone pressed pause and again to play. That is, there is no interruption or stuttering, but a slight attenuation of the sound. It is difficult to describe in words, but in fact I have met such an implementation for the first time, and I am pleasantly surprised, in the case of communication dumps, my hearing does not hurt. As for the range, it is unlikely that you will be able to calmly walk around the hall during training, for example, leaving the phone at one end. For me, this is not an obstacle, at training I am without headphones, it seems to me that if during sports I create additional pressure through the headphones, then my head will burst. But for the owners of smart watches, you can download music to the watch and connect to it.
There is also a common problem with this type of headphones, it is the lag of the audio track when watching a video. Syllable D900P does not have this problem, which is very important, especially if you are watching any tutorials. So when choosing, pay attention to this, read the reviews.
In general, the connection quality suits me perfectly, the Chinese did not cheat with the bluetooth version, which I think played a role, since the competitor TWS-16 is not so smooth.
Considering that I only have one earpiece from them, that is, there is no need for additional costs for signal transmission, but it has very frequent interruptions, which are expressed by stuttering, and which happen even if the phone was nearby. And getting rid of them is not so easy, they themselves rarely disappear, you have to reconnect.

5.2 Sound

Here we get to the most important thing. Let's take the type and size of the headphones into account and get a pretty decent sound for listening to music. For people who are "sick" with sound, this is not quite a suitable option. Here we give a higher score for compactness and portability. For comparison, I have this model: the sound is not inferior. They sound no worse than local wired Sony, Philips, Xiaomi, JBL at a price of ~ $ 20-40.
Bass - Calm, soft, I would say even a little missing, in some cases you want to tighten it up a little. Lovers pile harder - by.
Medium / high - everything is standard for vacuum headphones. Of course, high-pitched ones prevail, but the voice is drawn quite well. Choosing the right ear cushions does not hurt your hearing.
For most users, the sound will be quite enough, the sound does not cut, does not rattle, it is quite pleasant to listen to. For audiophiles, they themselves understand everything perfectly.
In comparison with TWS-16, it is certainly difficult to compare, two against one. But Syllable sounds more interesting.
The volume reserve is quite enough.
Speaking of the quality while talking on the phone, everything is obvious here, I hear well, they don't hear me very well, somewhere in the distance. But, I was pleased with one feature. Often in these types of headphones during a telephone conversation, you hear speech only in one, the main earpiece. Immediately, speech is transmitted to both, this is also a big plus. When the call ends, you hear: call ended, and if you canceled the call: call canceled.

6. Conclusions

In summary, I am completely satisfied with this purchase. As I wanted, I received completely wireless headphones, small in size and weight, with a comfortable fit, good playing time and good sound. All this is complete with a case that allows you to conveniently transport them, and also not to worry about discharge. It is very pleasant that all sorts of little things have been thought out, such as: a magnetic cover, a button for turning on the case, smart turning on the headphones when removing, soft attenuation in case of loss of connection. Comparing them with TWS-16, they are inferior only to the size of the earphone and case, but this was not a disadvantage, so even now I would prefer the Syllable D900P.
I liked the review +19 +34

One year after the approval of the Bluetooth 4.1 specifications, the organizationThe Bluetooth Special Interest Group (SIG) has released an updated 4.2. In Bluetooth 4.2, the speed of information exchange between Bluetooth Smart devices has been increased: the size of data packets has been increased 10 times, and the speed has increased 2.5 times.

One year after the approval of the Bluetooth 4.1 specifications, the organization The Bluetooth Special Interest Group (SIG) has released an updated 4.2. In Bluetooth 4.2, the speed of information exchange between Bluetooth Smart devices has been increased: the size of data packets has been increased 10 times, and the speed has increased 2.5 times. Improved work with devices of the Internet of Things segment, thanks to Internet Protocol Support Profile (IPSP) now supports direct Internet connection via protocol Ipv6 / 6LoWPAN and Bluetooth Smart Device Management.

In other words, devices will be able to connect directly to the Internet through an access point or router without additional connections and transmitters. In addition, they promise a high degree of protection against tracking via Bluetooth-connection and data encryption. The unilateral tracking process is no longer possible, you need to confirm the connection. Of course, they promise to reduce energy consumption. The first products with Bluetooth 4.2 may appear in the first half of 2015.

Source: bluetooth

Kirkland, WA - December 03, 2014

The Bluetooth Special Interest Group (SIG) officially adopted version 4.2 of the Bluetooth core specification this week. Key updates in 4.2 improve privacy and increase speed, and a soon-to-be ratified profile will enable IP connectivity. Bluetooth 4.2 opens up new opportunities for developers, OEMs and the industry to build a better user experience for consumers while creating use cases never before imagined.

“Bluetooth 4.2 is all about continuing to make Bluetooth Smart the best solution to connect all the technology in your life - from personal sensors to your connected home. In addition to the improvements to the specification itself, a new profile known as IPSP enables IPv6 for Bluetooth, opening entirely new doors for device connectivity, ”said Mark Powell, executive director of the Bluetooth SIG. "Bluetooth Smart is the only technology that can scale with the market, provide developers the flexibility to innovate, and be the foundation for the IoT."

Privacy and Security
Bluetooth 4.2 introduces industry-leading privacy settings that lowers power consumption and builds upon the government-grade security features of the Bluetooth specification. The new privacy features put control back into the hands of the consumer by making it difficult for eavesdroppers to track a device through its Bluetooth connection without permission. For example, when shopping in a retail store with beacons, unless you’ve enabled permission for the beacon to engage with your device, you can’t be tracked.

Speed
Bluetooth 4.2 increases the speed and reliability of data transfers between Bluetooth Smart devices. By increasing the capacity of Bluetooth Smart packets, devices transfer data up to 2.5 times faster than with previous versions. Increased data transfer speeds and packet capacity reduces the opportunity for transmission errors to occur and reduces battery consumption, resulting in a more efficient connection.

Internet Connectivity
Building on the capabilities released earlier with Bluetooth 4.1 and the new features released in 4.2, the Internet Protocol Support Profile (IPSP) will allow Bluetooth Smart sensors to access the Internet directly via IPv6 / 6LoWPAN. IP connectivity makes it possible to use existing IP infrastructure to manage Bluetooth Smart “edge” devices. This is ideal for connected home scenarios that need both personal and wide area control. This profile will be ratified by the end of the year.

Bluetooth 5.0 became a reality. Compared to Bluetooth 4.0, the new version has double the bandwidth, quadruple the range and a whole host of other improvements. Consider the advantages of Bluetooth 5.0 over its predecessors, including an example CPU CC2640R2F from Texas Instruments.

The popularity of the Bluetooth 4 protocol version, as well as some of its limitations, became the reasons for the creation of the next Bluetooth 5 specification. The developers set themselves a number of goals: expanding the range, increasing the bandwidth when sending broadcast packets, improving noise immunity, and so on.

Now that the first devices with Bluetooth 5 have begun to appear, users and developers rightly have questions: which of the previously announced promises have come true? How much has the range and data transfer rate increased? How did this affect the consumption level? How has the approach to the formation of broadcast packets changed? What improvements have been made to improve noise immunity? And, of course, the main question is - is there backward compatibility between Bluetooth 5 and Bluetooth 4? Let's answer these and some other questions and consider the main advantages of Bluetooth 5.0 over its predecessors, including the example of a real processor with Bluetooth 5.0 support from the company. Texas Instruments.

Let's start our review of Bluetooth 5.0 by answering the most frequently asked question about backward compatibility with Bluetooth 4.x

Is Bluetooth 5.0 backward compatible with Bluetooth 4.x?

Yes, it does. Bluetooth 5 has taken over most of the features and extensions of Bluetooth 4.1 and 4.2. For example, Bluetooth 5 devices retain all of the Bluetooth 4.2 data security enhancements and support the LE Data Length Extension. It is worth recalling that thanks to the LE Data Length Extension, starting from Bluetooth 4.2, the packet data unit (PDU) size with an established connection can be increased from 27 to 251 bytes, which allows you to increase the data exchange rate by 2.5 times.

Due to the large number of differences between the protocol versions, the traditional mechanism for negotiating parameters between devices when establishing connections is preserved. This means that before starting to exchange data, the devices "get acquainted" and determine the maximum data transmission frequency, message length, and so on. The default settings are Bluetooth 4.0. The transition to the Bluetooth 5 parameters occurs only if during the negotiation process it turns out that both devices support the later version of the protocol.

Speaking of the tools that are already available to developers, the new CC2640R2F processor and the free BLE5-Stack from Texas Instruments are worth noting. To the delight of the developers, BLE5-Stack is based on the previous version of BLE-Stack, and changes in its use only affected the new features of Bluetooth 5.0.

How has the data transfer rate increased in Bluetooth 5?

Bluetooth 5 uses a wireless connection with a physical data transfer rate of up to 2 Mbps, which is double that of Bluetooth 4.x. It should be noted here that the effective data exchange rate depends not only on the physical bandwidth of the transmission channel, but also on the ratio of service and useful information in the packet, as well as on the accompanying "overhead" costs, for example, the loss of time between packets (Table 1).

Table 1. Data exchange rate for different versionsBluetooth

In Bluetooth versions 4.0 and 4.1, the physical bandwidth of the channel was 1 Mbit / s, which, with a PDU data packet length of 27 bytes, made it possible to achieve an exchange rate of up to 305 kbit / s. Bluetooth 4.2 introduces the LE Data Length Extension. Thanks to him, after establishing a connection between devices, it became possible to increase the packet length to 251 bytes, which led to an increase in the data exchange rate by 2.5 times - up to 780 kbit / s.

Bluetooth version 5 retains support for LE Data Length Extension, which, together with an increase in physical bandwidth up to 2 Mbps, allows data exchange rates of up to 1.4 Mbps to be achieved.

As practice shows, such acceleration of data transfer is not the limit. For example, the CC2640R2F wireless microcontroller is capable of operating at speeds up to 5 Mbps.

It is worth mentioning a common misconception that the increase in throughput up to 2 Mbps was achieved by reducing the range. Of course, physically the transceiver chip (PHY) when operating at 2 Mbit / s has 5 dBm less sensitivity than when operating at 1 Mbit / s. However, in addition to sensitivity, there are other factors that contribute to an increase in the range, for example, the transition to data encoding. For this reason, all other things being equal, Bluetooth 5 is more reliable and has a longer range than Bluetooth 4.0. This is discussed in detail in one of the following sections of the article.

How to activate high speed data transfer mode in Bluetooth 5?

When a connection is established between two Bluetooth devices, the Bluetooth 4.0 settings are initially used. This means that at the first stage, the devices exchange data at a speed of 1 Mbps. Once the connection is established, the Bluetooth 5.0 enabled wizard can start the PHY Update Procedure to set the maximum speed to 2 Mbps. This operation will be successful only if the slave also supports Bluetooth 5.0. Otherwise, the speed remains at 1 Mbps.

For developers who have previously used the BLE-Stack from Texas Instruments, the good news is that the new BLE5-Stack has a single function, HCI_LE_SetDefaultPhyCmd (), allocated to perform the above procedure. Thus, when upgrading to Bluetooth 5.0, TI users will have no problem with the initial initialization. An example posted on the GitHub portal will also be useful for developers, which allows you to evaluate the operation of two CC2640R2F microcontrollers operating as part of the CC2640R2 LaunchPads in High Speed ​​and Long Range modes.

How has the range of Bluetooth 5 increased?

The Bluetooth 5.0 specification says it has four times the range of Bluetooth 4.0. This is a rather subtle question, which is worth dwelling on in more detail.

First, the concept of "four times" is relative and is not tied to a specific range in meters or kilometers. The fact is that the radio transmission range strongly depends on a number of factors: the state of the environment, the level of interference, the number of simultaneously transmitting devices, and so on. As a result, not a single manufacturer, as well as the developer of the Bluetooth SIG standard himself, gives specific values. The increase in range is estimated compared to Bluetooth 4.0.

For further analysis, it is necessary to perform some mathematical calculations and estimate the power budget of the radio channel. When using logarithmic values, the radio channel budget (dB) is equal to the difference between the transmitter power (dBm) and the receiver sensitivity (dBm):

Radio channel budget = powerT X(dBm) - sensitivityR X(dBm)

For Bluetooth 4.0, the standard receiver sensitivity is -93 dBm. Assuming a transmitter power of 0 dBm, the budget is 93 dB.

Increasing the range by four times would require a 12 dB increase in budget, which gives a value of 105 dB. How is this value supposed to be achieved? There are two ways:

• increasing the power of transmitters;
• increasing the sensitivity of receivers.

If you go along the first path and increase the transmitter power, this will inevitably cause an increase in consumption. For example, for the CC2640R2F, switching to an output power of 5 dBm leads to an increase in the current consumption up to 9 mA (Figure 1). At a power of 10 dBm, the current will increase to 20 mA. This approach does not look attractive for most battery-powered wireless devices and is not always suitable for IoT, and this is the area where Bluetooth 5.0 was primarily oriented. For this reason, the second solution seems to be preferable.

There are two ways to increase the receiver sensitivity:

• decrease in transmission speed;
• using data encoding Coded PHY.

Reducing the data rate by a factor of eight theoretically increases the receiver sensitivity by 9 dB. Thus, only 3 dB is missing to the coveted value.

The required 3 dB can be obtained using additional Coded PHY coding. Previously, in Bluetooth 4.x versions, the bit coding was 1: 1 unambiguous. This means that the data stream was directed directly to the differential demodulator. In Bluetooth 5.0 when using Coded PHY, there are two additional transmission formats:

• with 1: 2 coding, in which each data bit is mapped to two bits in the radio data stream. For example, a logical "1" is represented as the sequence "10". At the same time, the physical speed remains equal to 1 Mbit / s, while the real data transfer rate drops to 500 kbit / s.
• With 1: 4 encoding. For example, logical "1" is represented by the sequence "1100". In this case, the data transfer rate is reduced to 125 kbps.

The described approach is called Forward Error Correction (FEC) and allows you to detect and correct errors on the receiving side, rather than requesting retransmission of packets, as was the case in Bluetooth 4.0.

Everything looks good on paper. It remains only to find out to what extent these theoretical calculations correspond to reality. Let's take the same CC2640R2F microcontroller as an example. Thanks to various improvements and new modulation modes for Bluetooth 5.0, the transceiver of this processor has a sensitivity of -97 dBm at 1 Mbps and -103 dBm when using Coded PHY and 125 kbps. Thus, in the latter case, only 2 dBm is not enough to reach 105 dB.

To estimate the range of the CC2640R2F, engineers at Texas Instruments conducted a field experiment in Oslo. At the same time, from the point of view of the noise level, the environment in this experiment cannot be called “friendly”, since the business part of the city was located in the immediate vicinity.

To obtain a power budget of more than 105 dB, it was decided to increase the transmitter power to 5 dBm. This resulted in an impressive 108 dBm total (Figure 2). During the experiment, the operating range was 1.6 km, which is a very impressive result, especially considering the minimum level of consumption of radio transmitters.

How has the approach to Bluetooth 5 broadcast messages changed?

Previously, Bluetooth 4.x used three dedicated data channels to establish connections between devices (37, 38, 39). With their help, the devices found each other and exchanged service information. They could also transmit broadcast data packets. This approach has disadvantages:

• with a large number of active transmitters, these channels can simply be overloaded;
• more and more devices use point-to-point connectionless broadcasts. This is especially important for the Internet of Things (IoT);
• the new Coded PHY coding system will require eight times longer to establish a connection, which will additionally load broadcast channels.

To solve these problems in Bluetooth 5.0, it was decided to switch to a scheme in which data is transmitted on all 37 data channels, and service channels 37, 38, 39 are used to transmit pointers. The pointer refers to the channel on which the broadcast message will be transmitted. In this case, the data is transmitted only once. As a result, it is possible to significantly unload service channels and eliminate this bottleneck.

It is also worth noting that now the data length of a broadcast packet can be up to 255 bytes instead of 6 ... 37 bytes PDU in Bluetooth 4.x. This is extremely important for IoT applications, as it minimizes transmission overhead and eliminates the need for connections, and therefore reduces consumption.

Does Bluetooth 5 support Mesh networks?

Texas Instruments Bluetooth 5 Solutions

One of the very first microcontrollers with Bluetooth 5.0 was the high-performance CC2640R2F processor from Texas Instruments.

The CC2640R2F is based on a modern 32-bit ARM Cortex-M3 core with an operating frequency of up to 48 MHz. The radio transmitter is controlled by a second 32-bit ARM Cortex-M0 core (Figure 3). In addition, the CC2640R2F features rich digital and analog peripherals.

The advantage of the CC2640R2F microcontroller is also a low consumption level (table 2). This applies to all modes of operation. For example, in active mode, when receiving data over a radio channel, the consumption is 5.9 mA, and when transmitting, 6.1 mA (0 dBm) or 9.1 mA (5 dBm). When going into sleep mode, the supply current drops to 1 μA altogether.

The combination of three such important qualities as support for Bluetooth 5.0, low power consumption and high peak performance makes the CC2640R2F a very interesting solution for the Internet of Things. At the same time, using this microcontroller, you can create the entire range of IoT devices: autonomous sensors that operate for several years from one battery, bridges between an additional control processor and the Bluetooth 5.0 channel, complex applications that require high computing power.

Table 2. Consumption of wireless microcontrollerCC2640 R2 Fwith the supportBluetooth 5

Working hours	Parameter	Value (at Vcc = 3V)
Active computing	μA / MHz ARM® Cortex®-M3	61 μA / MHz
	Coremark / mA	48,5
	Coremark @ 48 MHz	142
Radio exchange	Peak current when receiving, mA	5,9
	Peak current during transmission, mA	6,1
Sleeping mode	Sensor controller, μA / MHz	8,2
	Sleep mode with RTC on and memory retention, mA	1

To get started quickly with the CC2640R2F, Texas Instruments has prepared a traditional debug kit (Figure 4). With the help of a pair of such devices, you can evaluate the speed and range of radio transmission via Bluetooth 5.0. To do this, you can use ready-made examples or create your own application based on the free BLE 5 stack 1.0 protocol (www.ti.com/ble).

Conclusion

The new version of the Bluetooth 5.0 protocol is focused on meeting the needs of the Internet of Things (IoT). Compared to Bluetooth 4.0, it has a number of quality improvements:

• data transfer speed doubled and reached 2 Mbps;
• transmission range has quadrupled due to data coding Coded PHY and Forward Error Correction (FEC);
• the throughput of broadcast messages increased by 8 times.

In addition, Bluetooth 5.0 provides backward compatibility with Bluetooth 4.x devices and also supports most extensions of later protocol versions.

You can now evaluate the capabilities of Bluetooth 5.0 using instruments manufactured by Texas Instruments. The company produces a high-performance and low-power microcontroller CC2640R2F, provides a free BLE 5 stack 1.0 and many ready-made examples for the LAUNCHXL-CC2640R2 debug kit.

Literature

1. Bluetooth Core Specifcation 5.0 FAQ. 2016. Bluetooth SIG.