Bluetooth 5 is becoming an important part of Internet of things applications-Industry Information

What is Bluetooth 5?

　　If you own a car or a smart phone, you will probably use Bluetooth at least once in your life. Bluetooth everywhere: speakers, wireless headphones, cars, wearable devices, medical equipment, and even shoes!

　　There are two kinds of Bluetooth devices: one called classic Bluetooth (for wireless speakers, car information entertainment systems and headphones), and the other known as low power Bluetooth (BLE).

　　BLE is more prominent in power-critical applications (such as battery-powered devices) and in infrequent transmission of small amounts of data (such as sensor applications).

　　These two Bluetooth devices are incompatible with each other (even though they have the same brand or even the same specification document), and classical Bluetooth devices cannot communicate directly with low-power Bluetooth devices. But there is also a dual mode bluetooth device on the market, which supports low-power Bluetooth and classic Bluetooth.

　　Because many Internet of things systems involve small devices and sensors, low power Bluetooth (BLE) has become a more common protocol in the Internet of things (relative to the classic Bluetooth). In December 2016, the Bluetooth Technology Alliance (SIG), behind the Bluetooth standard, released the 5 version of Bluetooth. Most enhancements and features introduced in this release are focused on low-power Bluetooth.

　　What are the new functions of Bluetooth 5.0?

　　So what are the new features of Bluetooth 5 compared with previous versions?

　　Three main functions:

　　1、Two times speed

　　2、Four times range

　　3、Eight times the advertising message capacity

　　Let's take a closer look at each of them to see what potential networking applications can be utilized.

　　Two times speed

　　In the earlier version of Bluetooth (4.2 and earlier version), the low power Bluetooth (BLE) data rate was set to a fixed 1Mbps. In Bluetooth 5, a new mode with data rate of 2Mbps is introduced. This new data rate also provides some additional benefits:

　　▲Because the same amount of data is transmitted in a relatively short time, the power consumption is reduced.

　　▲Because of the reduction of radio connection time, the wireless coexistence is improved.

　　One disadvantage of using 2Mbps mode is that it has the potential to reduce the transmission range, because higher speeds result in lower radio sensitivity at the receiver. However, some application scenarios are acceptable for applications that sacrifice a little bit of scope for higher data transfer speeds.

　　Compared with other low power wireless protocols (such as ZigBee, Z-Wave, Thread), BLE provides higher data rates, even at the original 1 Mbps data rate. With the addition of the new high speed mode (2 Mbps), more potential Internet of things applications become more feasible. Examples include video streaming, audio streaming and burst large data transmission, such as images.

　　Four times range

　　Bluetooth 5 also introduces a remote mode, which uses an error correction technique called FEC. FEC allows the receiver to recover data from errors caused by noise and interference. Therefore, when an error occurs, the receiver can use the redundancy of the data to recover the originally transmitted data, rather than requiring a retransmission of the data.

　　This remote mode is called the coded PHY mode. The obvious advantage of using this new model is to increase the transmission range, and the disadvantage is that the average power consumption increases and the transmission rate is reduced (125 Kbps or 500kbps, depending on the coding scheme used).

　　When testing in remote mode, the range of sight distance can be recorded as far as 800 meters. This makes it possible to use BLE in applications such as devices that need to communicate with hundreds of meters away. For example, remote control equipment, home automation and industrial applications.

　　Bluetooth 5 will increase the communication distance to four times the original one. This means that BLE technology is finally available in smart homes. Users can control their home smart products through BLE, from smart bulbs to smart locks, and now the smart devices in a family can be connected with BLE. Compared to the WiFi technology with huge power consumption, the advantages of BLE for smart home products are very obvious.

　　Eight times the advertising message capacity

　　In Low Power Bluetooth (BLE), devices can run three main states. They are advertisements, scans, or connections. To connect two low power Bluetooth devices, one device must be advertise, the other device must scan, and then start the connection. Advertising essentially involves advertising groups, which allow another scanning device to find them, after the advertising group is allowed, and the scanning device can decide to start the connection.

　　In the earlier version of Bluetooth, the upper limit of the payload of advertising data is 31 bytes. In Bluetooth 5, a new advertising mode is introduced: expanding advertising. The extended advertisement allows each packet to send up to 255 bytes of payload data instead of the original 31 byte constraint.

　　Advertisements can be used in all low-power devices, but a prominent application of this state is beacon technology. Beacon equipment maintains advertising status and simply advertised data for others to browse and read data. With the increase in advertising data capacity of Bluetooth 5, beacons can now transmit more data and unlock more new Internet of Things applications and uses.

　　Conclusion

　　As we can see, Bluetooth 5 introduces some functions that can be applied to a wide range of potential Internet of things. However, there are several key points to note:

　　▲According to the official Bluetooth specification, the new remote and high-speed mode is only optional, so the two new modes may not be supported by the chipsets or devices that claim to support Bluetooth 5.

　　▲In order to make use of these new functions, two BLE devices that communicate with each other need to support Bluetooth 5 and support the functions of interest. For example, in order to enable long distance transmission of sensor data between sensor devices and smartphones using remote modes, sensor devices and smartphones need to support Bluetooth 5 and remote mode.

　　▲Smart phones still have difficulty in supporting Bluetooth 5 and its new features. Even with new hardware support, its API also needs to allow mobile developers to use these functions.

　　Nevertheless, the introduction of Bluetooth 5 into potential new Internet of Things applications, whether on the mobile or embedded side, will inevitably be widely adopted!