What is Bluetooth. What does the bluetooth version affect? How to understand Bluetooth versions Firmware updates bluetooth 4.0 to 4 1
All modern smartphones are equipped with fourth generation Bluetooth – some have version 4.0, some 4.1, and some 4.2. Meanwhile, the fifth version of the “blue tooth” was released. In this article we will talk about its advantages over Bluetooth 4.2 and how these advantages will be applied in practice.
Two times faster
Data via Bluetooth 5th generation will now be transmitted at maximum speed6.25 MB/s - previously 3.125 MB/s. This is still much less than wired competitors:
- Apple Lightning – 60 MB/s
- USB 2.0 – 60 MB/s
- USB 3.0 – 625 MB/s
- USB 3.1 – 1210 MB/s
But that’s why they’re wired!
As a result, the speed of synchronization of smart watches with a smartphone and Internet of Things elements with each other and with the base will increase.
Four times further
Indoor range has increasedfrom 10 to 40 meters, on the street - from 50 to 200 meters.
It will be possible to run at the stadium without a smartphone in your pocket. Leave it in your backpack, put on Bluetooth headphones and run - there won't be anything hanging around in your pocket. Maybe it was your phone that stopped you from running a marathon! True, you can’t run 42 kilometers 195 meters with wireless headphones.
Perhaps Fabregas is not included in the squad because his Bluetooth 4.2 headphones interfere with him
An increased range of action is especially important for organizing the Internet of Things. If for apartments the older versions of Bluetooth were somehow enough, then in a large house compromises had to be made. Now you can easily place some IoT element in the yard, away from the rest.
Eight times more data via broadcast channels
Broadcast channels are needed for the Internet of Things to work with third-party Bluetooth devices without prior connection. In this mode, you can now transmit more information:255 bytes versus 31 in Bluetooth 4.2.
I’ll explain with an example why broadcast channels are needed. Let's imagine a modern hospital in which the Internet of Things is implemented. A person comes in and information is immediately sent to him via Bluetooth about which office he needs to go to. He can’t get anything else because he’s not fully connected to the hospital Internet of Things.
The volume of this information is 31 bytes, because Bluetooth 4.2 is used. And with version 5, a person will also receive the doctor’s name, approximate waiting time and the head doctor’s phone number for complaints - the size of this data is already 255 bytes.
Consumes 2.5 times less energy
It seems that with increased speed and range, Bluetooth 5 will become more power hungry. In fact, everything is exactly the opposite - the new standard is much more economical in energy consumption. For smartphones with 3,000 mAh batteries, Bluetooth 4.2 power consumption was not critical. In the case of smart watches, the increase in autonomy can be noticeable, although, of course, it needs to be tested in practice.
Serial connection system
Scaling the Internet of Things will become easier thanks to the new serial connection system. Previously, each device connected to a common base device, but now it will be enough to connect to a neighboring element.
Let's remember physics!
Maybe someday we will see a city IoT system not within an apartment or house, but within an entire district or even a city? And it will be based on the energy-efficient and easily scalable Bluetooth 5.
Why else is Bluetooth connected to the Internet of Things? The fact is that the elements of IoT are too fragmented: each manufacturer does something (or everything) differently. Bluetooth is one of the things that unites them all. It is used in almost all devices: phones, watches, laptops, cars and so on.
By the way, the new standard is backward compatible with older protocols.
When to expect?
Yes, we've already waited. All the necessary documentation for the development of devices and software with support for Bluetooth 5 appeared on the official website at the beginning of the year, and recently the first smartphones with the fifth version of the “blue tooth” were released.
Bluetooth 5 is not a revolution by any means, but rather an evolutionary development of the technology. The new standard only improved the performance of the previous one, but did not teach the “blue tooth” to do anything new. Protocol 4.2 does everything that Bluetooth 5 can do, only several times worse.
Hello.
On December 3, 2014, Bluetooth SIG officially announced bluetooth specification version 4.2.
The press release identifies 3 main innovations:
- increasing the speed of data reception and transmission;
- ability to connect to the Internet;
- improving privacy and security.
In this article I want to tell you how these 3 points are implemented. Anyone interested is 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 the low data transfer speed. Although no matter how you look at it, BLE was originally invented to save the energy of the source powering the device. And in order to save energy, you need to get in touch intermittently and transfer a little data. However, all the same, the entire Internet is filled with indignation about the low speed and questions about the possibility of increasing it, as well as increasing the size of the transmitted data.
And with the advent of version 4.2, Bluetooth SIG announced an increase in transmission speed by 2.5 times and the size of the transmitted packet by 10 times. How did they achieve this?
Let me tell you that these 2 numbers are related to each other, namely: the speed has increased because the size of the transmitted packet has increased.
Let's look at the PDU (protocol data unit) of the data channel: 
Each PDU contains a 16-bit header. So, this header in version 4.2 is different from the header in version 4.1.
Here is the version 4.1 header:
And here is the header 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 Length field is the sum of the payload lengths and the MIC (Message Integrity Check) field found in the PDU (if the latter is enabled).
If in version 4.1 the “Length” field has a size of 5 bits, then in version 4.2 this field has a size of 8 bits.
From here it is easy to calculate that the “Length” 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 versions 4.1 and 4.2, respectively. In fact, the maximum amount of data is even less, because The payload also contains L2CAP (4 octets) and ATT (3 octets) service data, but we will not consider this.
Thus, the size of transmitted user data has increased approximately 10 times. As for the speed, which, for some reason, increased not 10 times, but only 2.5 times, then we cannot talk about a proportional increase, because everything also depends on the guarantee of data delivery, because guaranteeing the delivery of 200 bytes is a little more difficult than 20.
2. Possibility of connecting to the Internet.
Perhaps the most interesting innovation is why Bluetooth SIG announced that version 4.2 makes the Internet of Things (IoT) better thanks to this feature.Back in version 4.1, L2CAP added the “LE Credit Based Flow Control Mode” mode. 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 signaling packets to indicate the amount of data being transferred, but requests from another device a credit for a certain amount of data to be transferred, thereby speeding up the transfer process. In this case, each time the receiving side receives a frame, it decreases the frame counter, and when the last frame is reached, it can break the connection.
3 new codes have appeared in the list of L2CAP commands:
- LE Credit Based Connection request – request for connection according to the credit scheme;
- LE Credit Based Connection response – response to connection based on the credit scheme;
- LE Flow Control Credit – message about the possibility of receiving additional LE frames.
In the package “LE Credit Based Connection request” 
there is an “Initial Credits” field 2 octets long, indicating the number of LE frames that the device can send at the L2CAP level.
In the response package “LE Credit Based Connection response” 
the same field indicates the number of LE frames that another device can send, and the “Result” field also indicates the result of the connection request. A value of 0x0000 indicates success, other values indicate an error. Specifically, a value of 0x0004 indicates that the connection was refused 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).
- IPSP (Internet Protocol Support Profile) profile, which defines support for transmitting IPv6 packets between devices that have BLE.
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 this device;
Devices with the router role that need to connect to another router can have the host role.
Oddly enough, 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 transmitting IPv6 packets, the 6LoWPAN standard is used - this is a standard for interaction using the IPv6 protocol over low-power wireless personal networks of the IEE 802.15.4 standard.
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 packet transmission is not included in the profile specification. This allows the programmer to write his own implementation of packet transmission.
3. Improved privacy and security.
One of the responsibilities of the Security manager (SM) is to pair two devices. The pairing process creates keys that are then used to encrypt communications. The pairing process consists of 3 phases:- exchange of information about pairing methods;
- generation of short-term keys (Short Term Key (STK));
- key exchange.
- 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, 5 more functions have appeared in the cryptographic toolbox of the security manager, and these 5 are used only to service the new pairing process “LE Secure Connections”. These functions generate:
- LTK and MacKey;
- confirmatory variables;
- authentication check variables;
- 6-digit numbers used for display on connected devices.
So, if during pairing in the 2nd phase using the “LE legacy pairing” method, 2 keys were generated:
- Temporary Key (TK): 128-bit temporary key used to generate STK;
- Short Term Key (STK): 128-bit temporary key used to encrypt the connection
- Long Term Key (LTK): A 128-bit key used to encrypt subsequent connections.
- preventing tracking, because Now, thanks to “Numeric Comparison”, it is possible to control the ability to connect to your device.
- improving energy efficiency, because no longer requires additional energy to re-generate keys on each connection.
- Industry standard encryption to ensure sensitive data.
4. Is it already possible to touch?
Yes, I have.
NORDIC Semiconductor has released the "nRF51 IoT SDK" which includes a stack, libraries, examples and APIs for the nRF51 series devices. This includes:
- nRF51822 and nRF51422 chips;
- nRF51 DK;
- nRF51 Dongle;
- nRF51822 EK.
- short description;
- archive with the described SDK;
- kernel archive for Raspberry Pi, including its sources.
5. Conclusion.
The most expected thing for me personally, of course, was the increase in transmission speed and packet size of the transmitted data.
In the first quarter of 2015, the first chips supporting version 4.2 should appear, then there will be updates to mobile platforms and all this will allow us to add new capabilities to the world of Internet of Things.
Thank you for your attention.
Hardly any technology has been predicted to die more often than Bluetooth. At the same time, it is impossible not to recognize the idea of wireless communication as quite successful: version Bluetooth 1.0 appeared on the market more than 15 years ago, and Bluetooth has never been used in so many devices as it is now. All thanks to the version Bluetooth 4.0, which now, however, seems quite slow.
Upgrade to 4.1
One billion Bluetooth devices are sold every year. But there are still few gadgets with Bluetooth 4.1. At the moment, the Huawei TalkBand B1 smart bracelet has been announced. Many modern chipsets, such as those in the OnePlus smartphone, will also be upgraded to 4.1.
Replaces Bluetooth Low Energy(or Bluetooth Smart) - battery saving version. In this case, the range of action is limited to 10 m, and the data transfer rate is 1 Mbit/s, but no more than 10 mA is consumed during transmission.
And now comes the next stage: the Bluetooth Special Interest Group, which includes more than 8,000 companies, is preparing a version specification. Of course, you shouldn't expect any revolutionary changes, but mobile device users can expect some important innovations. CHIP decided to clarify some technical issues.
Most of the innovations in Bluetooth 4.1 relate to interference protection. Bluetooth is now a standard component of smartphones and tablets; LTE modules will soon begin to be introduced into these devices.
Unfortunately, Bluetooth uses the unlicensed 2.45 GHz frequency band (along with 2.6 GHz), as well as the LTE band in Russia and other countries. This may lead to mutual interference (see diagram). The problem is that the user has no influence on the LTE signal.
Bluetooth developers were required to do certain things to avoid interference. And that's exactly what was done in the new version.
To minimize interference, Bluetooth 4.1 will have a built-in LTE band filter. If an LTE transmitter interferes with data transmitted via Bluetooth, Bluetooth 4.1 will respond immediately
The LTE module sending and receiving data interferes with Bluetooth operation. In version 4.0, losses reached 75% of packets. Bluetooth version 4.1 is not as sensitive to interference from LTE. A noise filter protects the radio module. In difficult cases, the channel is automatically switched. The so-called Bluetooth 4.1 adaptive switching system will search for another channel where there is less interference, transmitting and receiving data on a different frequency. While with Bluetooth 4.0 LTE causes interference 75% of the time, with Bluetooth 4.1 this figure drops to 25%.
Receive and transmit data without interference
Devices with Bluetooth Low Energy are especially popular now. Especially for this power saving mode, version 4.1 has a new data transfer method that extends battery life.
Bluetooth users have learned the hard way about the problem of disconnected connections. It often happened that if the user went to another room, the connection was interrupted. After that, I had to configure the connection manually.
Fewer disconnections with new Bluetooth
If two Bluetooth devices move out of range, the connection will be lost. With Bluetooth 4.0, devices must return within 30 seconds to connect automatically. In version 4.1 this time increases to three minutes.
With Bluetooth 4.1, manufacturers can set fixed intervals so that the user does not have to set up a new connection every time after disconnecting. Bluetooth 4.1 can work with an interrupted connection for up to three minutes - previously this figure was no more than 30 seconds.
The fact that you don't have to be connected to a computer to use Bluetooth is demonstrated by an innovation designed specifically for 3D glasses that work in conjunction with a TV. Typically, this required connecting to multiple devices at once, so the picture on TVs often lagged. Everything should work better now.
Contactless Slave Broadcast in Bluetooth 4.1 is the second new feature that 3D movie fans will benefit from. The Bluetooth connection is only in one direction, the TV sends data at fixed intervals, the 3D glasses receive data but do not send any response connections to the TV.
Flexible connections with Bluetooth 4.1
The Bluetooth 4.1 connection architecture operates according to the Master-Slave principle. One device acts as a master, and the second as a slave. All devices can operate both as masters and slaves.
Thus, data from a fitness bracelet or heart rate monitor can now be transferred directly to a smartphone, which will then analyze it. Previously, direct interaction between a fitness bracelet and a smartphone was impossible.
Two benefits of upgrading Bluetooth: First, you don't have to worry about compatibility. Bluetooth 4.0 and Bluetooth 4.1 are completely compatible. A new chip for Bluetooth 4.1 is also not needed. Bluetooth 4.1 will be available via Bluetooth 4.0 firmware update.
Experts also predict that Bluetooth 4.1 will support IPv6. Now this is not the case. Since the new version of Bluetooth fully supports IPv6, all Bluetooth devices will be assigned an IP address and will be accessible over the Internet. So we can say that the Bluetooth revolution has already begun.
Bluetooth in comparison
Bluetooth has been around for 15 years, with new versions coming out every two years. Version 4.0 introduced a low-power profile. Since its predecessors do not have it, the 4.0 and 4.1 protocols are not backward compatible. In 4.1 it is planned to work using the IPv6 protocol.
| Bluetooth 4.0 | Bluetooth 3.0 | Bluetooth 2.x | Bluetooth 1.x | ||
|---|---|---|---|---|---|
| Base speed | 1 Mbit/s | 1 Mbit/s | 1 Mbit/s | 1 Mbit/s | 1 Mbit/s |
| Enhanced Data Rate (EDR) | 3 Mbit/s | 3 Mbit/s | 3 Mbit/s | 3 Mbit/s | No |
| High Speed | 54 Mbit/s | 54 Mbit/s | 54 Mbit/s | No | No |
| Range (max./min. power) | 100 m/10 m | 100 m/10 m | 100 m/no | 100 m/no | 100 m/no |
| Low Power Mode | Yes | Yes | No | No | No |
| Dual profile (simultaneous role as Slave and Master) | Yes | No | No | No | No |
| IPv6 support | getting ready | No | No | No | No |
| NFC pairing | Yes | Yes | Yes | Yes | No |
| 128-bit AES encryption | Yes | Yes | No | No | No |
Photos in the article: manufacturing companies
The updated protocol for wireless data exchange Bluetooth 4.1 should be released this year. The new version of the “blue tooth” will allow the device to directly interact with this standard and the cloud service. If the current version of Bluetooth 4.0 has a range of 30 m, not allowing mobile devices and PCs to exchange files at a distance exceeding this value, then the Bluetooth 4.1 wireless connection will be able, using cloud capabilities for its own purposes, to significantly (albeit indirectly) expand the limit current range.
What exactly is the advantage of this innovation? Considering the growing popularity of fitness gadgets and wearable devices, by equipping their device with a module supporting Bluetooth 4.1, the manufacturer will be able to remove the middle link in the chain “gadget - smartphone/tablet - access to cloud service” and implement the connection directly, bypassing additional interfaces, etc. .
In principle, from a technical point of view, it is possible to implement a connection to the cloud infrastructure today, but for this it is necessary to use various kinds of network devices and so-called hubs with a full-fledged operating system, the role of which can be taken on by mobile electronics.
It is planned that the new Bluetooth network will become a truly huge infrastructure with a completely new approach to the interaction of all kinds of portable electronics and conventional equipment. Ultimately, this will allow the implementation of an updated principle of remote monitoring and control. For example, data directly from a wearable medical device can immediately go to the cloud system, and from there it will go to the mobile device of your treating doctor. And a patient who owns a wearable gadget that supports Bluetooth 4.1 technology does not need to be located in close proximity to the doctor.
A module with Bluetooth 4.1 will be able to take on the role of a hub, receiving signals from other Bluetooth devices. The final specifications of the Bluetooth 4.1 protocol should be finalized by the end of this year, and developers should focus on two key areas: the Low-Power component of the updated technology with a focus on popular wearable devices, as well as full-fledged Bluetooth 4.1 with radio frequency control functions and a focus on the use of the module in personal computers and laptops.
Hardly any technology has been predicted to die more often than Bluetooth. At the same time, it is impossible not to recognize the idea of wireless communication as quite successful: the Bluetooth I.0 version appeared on the market more than 15 years ago, and Bluetooth has never been used in so many devices as it is now. All thanks to Bluetooth 4.0, which now, however, seems quite slow. Bluetooth Low Energy (or Bluetooth Smart) is replacing it - a battery-saving version. In this case, the range of action is limited to 10 m, and the data transfer rate is 1 Mbit/s, but no more than 10 mA is consumed during transmission. And now comes the next stage: the Bluetooth Special Interest Group, which includes more than 8,000 companies, is preparing the specification for Bluetooth 4.1. Of course, you shouldn't expect any revolutionary changes, but mobile device users can expect some important innovations.
Most of the new products are Bluetooth 4.1. refers to interference protection. Bluetooth is now a standard component of smartphones and tablets: soon LTE modules will begin to be introduced into these devices. Unfortunately, Bluetooth uses the unlicensed 2.45 GHz frequency band (along with 2.6 GHz) as well as the LTE band in Russia and other countries. This may cause mutual interference. The problem is that the user has no influence on the LTE signal. Bluetooth was required to do certain things to avoid interference. And that's exactly what was done in the new version. To minimize interference, Bluetooth 4.1 will have a built-in LTE band filter. If an LTE transmitter interferes with data transmitted via Bluetooth, Bluetooth 4.1 will respond immediately. The so-called Bluetooth 4.1 adaptive switching system will search for another channel where there is less interference, transmitting and receiving data on a different frequency. While with Bluetooth 4.0 LTE causes interference 75% of the time, with Bluetooth 4.1 this figure drops to 25%.
Receive and transmit data without interference
Devices with Bluetooth Low Energy are especially popular now. Especially for this power saving mode, version 4.1 has a new data transfer method that extends battery life. Bluetooth users have learned the hard way about the problem of disconnected connections. It often happened that if the user went to another room, the connection was interrupted. After that, I had to configure the connection manually. With Bluetooth 4.1, manufacturers can set fixed intervals so that the user does not have to set up a new connection every time after disconnecting. Bluetooth 4.1 can work with an interrupted connection for up to three minutes - previously this figure was no more than 30 seconds. The fact that you don't have to be connected to a computer to use Bluetooth is demonstrated by an innovation designed specifically for 3D glasses that work in conjunction with a TV. Typically, this required connecting to multiple devices at once, so the picture on TVs often lagged. Everything should work better now. Contactless Slave Broadcast in Bluetooth 4.1 is the second new feature that 3D movie fans will benefit from. The Bluetooth connection is only in one direction, the TV sends data at fixed intervals, the 3D glasses receive data but do not send any response connections to the TV.
Flexible connections with Bluetooth 4.1
The Bluetooth 4.1 connection architecture operates according to the Master-Slave principle. One device acts as a master, and the second as a slave. All devices can operate both as masters and slaves. Thus, data from a fitness bracelet or heart rate monitor can now be transferred directly to a smartphone, which will then analyze it. Previously, direct interaction between a fitness bracelet and a smartphone was impossible.
Two benefits of upgrading Bluetooth: First, you don't have to worry about compatibility. Bluetooth 4.0 and Bluetooth 4.1 are completely compatible. A new chip for Bluetooth 4.1 is also not needed. Bluetooth 4.1 will be available via Bluetooth 4.0 firmware update. Experts also predict that Bluetooth 4.1 will support IPv6. Now this is not the case. Since the new version of Bluetooth fully supports IPv6, all Bluetooth devices will be assigned an IP address and will be accessible over the Internet. So we can say that the Bluetooth revolution has already begun.
| Bluetooth 4.1 | Bluetooth 4.0 | Bluetooth 3.0 | Bluetooth 2.x | Bluetooth 1.x | |
| Base speed | 1 Mbit/s | 1 Mbit/s | 1 Mbit/s | 1 Mbit/s | 1 Mbit/s |
| EDR* | 3 Mbit/s | 3 Mbit/s | 3 Mbit/s | 3 Mbit/s | □ |
| High Speed | 54 Mbit/s | 54 Mbit/s | 54 Mbit/s | □ | □ |
| Range (max./min. power) | 100 m/10 m | 100 m/10 m | 100 m/□ | 100 m/□ | 100 m/□ |
| Low Power Mode | ■ | ■ | □ | □ | □ |
| Dual profile (simultaneous role as Slave and Master) | ■ | □ | □ | □ | □ |
| IPv6 support | getting ready | □ | □ | □ | □ |
| NFC pairing | ■ | ■ | ■ | ■ | □ |
| 128-bit AES encryption | ■ | ■ | □ | □ | □ |
