Now we are experiencing the third big connection in the Internet of Things stage, and the Bluetooth technology created in the mobile phone era is facing challenges. Ms. Li, Senior Marketing Manager of the Asia-Pacific Region of Bluetooth Technology Alliance, said: Facing the opportunities in the field of Internet of Things, Bluetooth has several technical features that must be overcome. First, because the Internet of Things will greatly increase the number of networked devices, the existing IPv4 support capacity will be limited, IPv6 technical support is imperative, and networking capacity will be tested; Secondly, portable mobile devices have stricter requirements on power consumption; After the Internet of Things is more closely integrated with life, security is also an important consideration. land
In order to conform to the trend of the times, Bluetooth low power consumption (BLE) technology is introduced, which has better signal-to-noise ratio and longer transmission distance than traditional Bluetooth, usually up to 50 meters, while the traditional one is only 6~8 meters. Bluetooth BLE has the advantages of low power consumption, power saving, small data transmission but high speed. Although there are many advantages, there are always problems such as short distance and poor networking ability in smart home, intelligent lighting and other fields.
Subsequently, at the end of 20 14, Bluetooth Technology Alliance launched a new Bluetooth 4.2 core specification, which made significant improvements in privacy protection, transmission speed and direct access to the Internet through IPv6 and 6LoWPAN, making the interconnection in the field of Internet of Things faster and safer. 2065438+In February, 2005, Bluetooth Technology Alliance established Bluetooth Intelligent mesh Working Group to help Bluetooth intelligent technology realize standardized mesh network functions.
Bluetooth mesh technology
Before introducing Bluetooth Mesh technology, we should first understand what a Mesh network is. Wireless Mesh network, also known as multi-hop network, consists of Mesh routers and mesh clients, in which the mesh routers form the backbone network, which is connected with wired Internet and is responsible for providing multi-hop wireless Internet connection for mesh clients. Wireless mesh network is a new network structure based on multi-hop routing and peer-to-peer network technology, which has the characteristics of mobile broadband. At the same time, it can be dynamically expanded, self-organized, self-managed, self-repaired and self-balanced.
The wireless Mesh network expands the wireless hotspots in the traditional WLAN into a truly large-scale wireless geothermal area. Wireless Mesh is very suitable for wireless LAN solutions covering large open areas (including outdoor and indoor).
Bluetooth Mesh was born out of CSR Mesh, a private protocol advocated by CSR. CSR Mesh is a brand-new Bluetooth intelligent solution launched by CSR in February 20 14. This technology mainly integrates Bluetooth configuration and control protocol on one chip, and makes use of star network and relay technology, so that each network can connect more than 65,000 nodes, and networks can also be interconnected. Finally, countless devices equipped with Bluetooth intelligence can be interconnected or directly controlled through the same mobile phone, tablet computer or PC, thus building a whole home automation.
Technical characteristics of CSR Mesh called home automation.
Feature 1: The power consumption of CSR Mesh is only a few tenths of that of Zigbee.
It can continuously transmit signals between Mesh networks through information transmission between nodes, so as to realize the function of controlling the target device without traditional gateway. So we can use the APP on the mobile phone or tablet to control it, which is very convenient to operate.
Feature 2: Interlocking encryption function ensures information security.
When referring to the performance of CSR Mesh technology in security, professionals point out that in such a home network composed of CSR Mesh, all data are encrypted by AES algorithm, and the transmission between data will be based on the classic nested key exchange &; The encryption protocol run by different-hellman-merkle. Whenever a new device wants to access the network, it needs to rely on the device's own 128-bit UUID (Universal Unique Identification Code) to facilitate the identification of the mobile phone APP, and then it has to pass the 64-bit code authentication before it can connect to the mobile phone, and only after the authentication can the device obtain a unique networking key for communication.
In addition to CSR, other manufacturers such as NXP have also introduced Bluetooth mesh solutions. The solution of NXP Bluetooth smart grid is different from other grid technologies, which may lead to flooding, broadcast storm and increase energy consumption. NXP's low-power solution can completely synchronize and route various protocols, thus achieving efficient end-to-end connection between nodes; It can innovatively improve the energy efficiency of the whole network by several orders of magnitude; It also has enhanced security and network self-organization function with self-healing function, and will protect the layered mesh architecture in the future to better support Bluetooth smart devices. The over-the-air wireless upgrade function it provides can help the deployed network upgrade. NXP's solutions can help developers and manufacturers realize multi-node communication design when developing smart home products, including lighting, sensors, thermostats and other home Bluetooth smart devices.
Advantages of Bluetooth Mesh Network
First, the cost is low: almost one billion smartphones are equipped with Bluetooth 4.0 every year, and the huge volume amortizes the software and hardware research and development costs of Bluetooth protocols and Bluetooth chips. The average cost of Bluetooth module is only about half that of other protocols. When Alibaba presented 9.9 yuan and 19.9 yuan, 9.9 yuan was a Bluetooth module and 19.9 yuan was a Wi-Fi module.
Second, ultra-low power consumption: moderate bandwidth, low transmission power and complete sleep mechanism make Bluetooth ultra-low power consumption. The appearance of BLE in Bluetooth 4.0 has brought the standby power consumption to microwatt level, and the startup speed is fast, unlike Wi-Fi, which takes hundreds of milliseconds to start once and consumes system power.
3. Multi-channel: Wi-Fi only defines 14 channels at 2.4GHz, while Bluetooth 4.0 defines 79 channels. In the common scene of China apartment building, smart home networking must have enough channels to avoid co-frequency interference. At this point, Bluetooth has completely defeated Wi-Fi. ZigBee only defines 27 channels of 2.4GHz, 868MHz and 9 15MHz, which is far from being competent for co-channel interference caused by large-scale household use.
4. Less coverage blind spots: Bluetooth ad hoc network reduces the requirement for coverage distance. The more nodes, the less coverage blind spots. In general, more than 5 Bluetooth bulbs or switches in a family can form a blind spot coverage for the whole family.
5. Transmission speed: The theoretical bandwidth limit of Bluetooth 4.2 is 24Mb, and the bandwidth can transmit short videos or pictures.
Seven, IPV6: Bluetooth 4.2 can directly access the Internet, and even reserved the future Internet standard, IPV6.
How will Bluetooth technology develop in the future?
The future development of Bluetooth technology mainly includes two aspects: technology and application. Technically, in addition to developing Bluetooth Mesh technology, Bluetooth technology will also break through the current communication distance of 10 meter and solve the problem of communication distance limitation. At the same time, the transmission speed of Bluetooth technology will be doubled without increasing energy consumption.
In the future, Bluetooth technology will not only transfer files, but also have more application scenarios. First, the lighthouse. The application of Bluetooth beacon has completely changed people's understanding of connection and information release. Beacon, which is familiar to many people, is used in retail. In fact, this is only a small part of the lighthouse market. Lighthouses can also be used in industry and agriculture. Second, positioning and discovery. Third, smarter automation solutions. Smart buildings, smart homes and smart cars can all be connected by Bluetooth in the future, including temperature control, door lock control and window control. Bluetooth is very suitable for these low-power devices. You can also connect all devices together through the function of Mesh to provide a complete solution, so as to learn more.
Finally, as for who will eventually become the standard in the field of smart home, Bluetooth Mesh has the advantages of lower power consumption and real interconnection, but it will take time to tell us who will win in the end.