Comparison of Bluetooth Mesh and ZigBee
1 Introduction of Comparison of Bluetooth Mesh and ZigBee
The Internet of Things technology has played an increasingly important role in today’s life, and it has rapidly spread and merged in various vertical industries. In our lives, various terminals are connected through the Internet of Things technology. These node networks collect and send data through the Internet for further processing, and receive commands from users through the Internet. Since the amount of data exchanged is not very large, narrowband Mesh technology can be used to solve the shortcomings of the traditional point-to-point, star or bus structure.
In a mesh topology, some devices that do not need to consider power consumption are used as routing nodes or relay nodes. In addition to processing their own business data, they are also responsible for storing and forwarding data. This makes the network of routers and terminal nodes more decentralized. There is no single point of failure in the Mesh network, so it is more reliable. The well-designed routing mechanism and data receiving and sending confirmation mechanism make the Mesh network more reliable and scalable.
Another advantage of the Mesh network is that it can rely on routing equipment to expand the network, so battery-powered equipment can operate with low power consumption for a long time. Since a single gateway can be used to collect data or control from multiple nodes distributed in a larger area, the cost is reduced.
Bluetooth Mesh and Zigbee are the two most popular PAN (Personal Area Network) technologies, and both support Mesh networks (ie, mesh topology). Zigbee is based on the IEEE 802.15.4 standard, and Bluetooth Mesh is a BLE-based network technology developed and released by SIG.
The Bluetooth Mesh network relies on Bluetooth Low Energy. Bluetooth low energy technology is a wireless communication protocol stack used by Bluetooth Mesh. Bluetooth Mesh is based on the network flooding broadcast of BLE Low Energy Bluetooth.
2. Detailed technical analysis of Comparison of Bluetooth Mesh and ZigBee
2.1 Differences in Mesh routing mechanism
For a network with a smaller number of nodes, the performance of the two is similar.
Bluetooth Mesh uses a flooding method to route mesh packets. This is called a controlled broadcast mode, which is also called network flooding. It is called “controlled” because not all nodes relay and forward data packets. Only those nodes on mains power (not battery power) can act as relay nodes (equivalent to ZigBee routing nodes). This mechanism is very effective when the number of nodes in the network is small. Bluetooth Mesh assumes that in most typical use cases, all end nodes will require the same command in any case, such as “turn on the light”. Considering that lighting is one of the most prominent scenarios of the Internet of Things, this method can provide good performance.
When the node is in a mobile state, Zigbee’s routing mechanism may be affected, because ZigBee’s dynamic routing maintenance will exchange a large number of routing protocol messages to update the routing table, which may cause network congestion.
Since the Zigbee node has less delay for larger data packets, it can encapsulate higher-layer frame headers and commands while providing good performance. It can be combined with unicast and broadcast to improve reliability. When the size of more than 12 data packets is sent on the link, the delay of Bluetooth Mesh will be higher due to the sub-packaging and reassembly performed at the network layer. Therefore, compared with Zigbee, in the transmission of a large number of message commands that require subcontracting and reassembly, the delay of Bluetooth Mesh will be higher, and Zigbee will perform better.
2.2 Radiofrequency of Comparison of Bluetooth Mesh and ZigBee
Both Zigbee and Bluetooth Mesh mainly work in the 2.4 GHz frequency band, which is already crowded due to the presence of a variety of other technologies in the same frequency band. Zigbee also supports other frequency bands in some parts of the world, but it can only operate on the 2.4 GHz frequency band in China. Bluetooth Mesh is based on the three broadcast channels of BLE for data transmission and reception, and it also works in the 2.4GHz frequency band.
2.3 Data rate of Comparison of Bluetooth Mesh and ZigBee
The standard rate of BLE 4.2 is 1Mbps, while BLE 5.0 has doubled, and the maximum communication speed is 2Mbps. Zigbee is based on 802.15.4, which limits the data rate to a maximum of 250Kbps. Therefore, compared with Zigbee, Bluetooth Mesh has a faster data rate.
2.4 Scope of Comparison of Bluetooth Mesh and ZigBee
The calculation of the node-to-node range depends on many factors, such as transmit power, operating frequency, receiver sensitivity, antenna, etc. Zigbee (at 2.4GHz) usually has a longer transmission distance than BLE 4.0. Without PA (power amplifier), Zigbee can basically reach 100 meters. The coverage of the newly released Bluetooth 5 standard is 4 times that of Bluetooth 4.2. That is 300 meters, so the Bluetooth Mesh network based on BLE 5.0 will have a longer transmission distance.
2.5 Power consumption of Comparison of Bluetooth Mesh and ZigBee
Zigbee and BLE have the same power consumption. In addition, the routing mechanism adopted in Zigbee makes its power supply efficiency slightly higher. However, as the rate of Bluetooth 5 increases, the Bluetooth Mesh will be faster to send data packets of the same size, and the working time of the transmitter and receiver will be further shortened.
2.6 Complexity of Comparison of Bluetooth Mesh and ZigBee
Zigbee has a smaller protocol stack, but its routing management is more complicated. In contrast, BLE-based Bluetooth Mesh is generally more complex, but the routing is very simple.
2.7 Security of Comparison of Bluetooth Mesh and ZigBee
Both are inherently safe. Both provide options for authentication and data encryption.
2.8 Ecosystem of Comparison of Bluetooth Mesh and ZigBee
Compared with BLE, Zigbee currently has a better ecosystem in the field of smart homes. Samsung’s smart product, Philips Hue also use Zigbee as the main home network technology. There are also a large number of smart home manufacturers in China that provide mature and stable Zigbee products.
From the perspective of application layer support, BLE and BLE-based Bluetooth Mesh are currently more suitable for lighting scenarios. For example, the Bluetooth Mesh products and ecology of the Tmall Genie Ecological Chain are becoming more mature and continuing to expand. While Zigbee is more used in smart home products, one of the reasons that most of the current market is Zigbee is also because the Bluetooth Mesh network based on BLE has only been commercialized on a large scale in the past two years.
However, BLE supports beacons, which means that in addition to lighting, applications based on Bluetooth Mesh can also be used for asset tracking, indoor positioning and navigation.
Zigbee Mesh has basically no related protocol stack support in most popular OS platforms (such as Android, OS X, etc.), and there are almost no consumer electronics devices that have embedded chips that support the Zigbee protocol.
BLE has become part of the most popular OS (such as Android, OS X, Windows, etc.), such as mobile phones, computers, mice, headsets, etc.
Therefore, compared with Bluetooth Mesh, each device in the Zigbee network can hardly reach the consumer terminal device directly, and it needs to use an additional gateway for data forwarding.
2.9 Cost of Comparison of Bluetooth Mesh and ZigBee
Bluetooth Mesh is based on BLE and has a larger ecosystem. Almost all smart devices are integrated with Bluetooth. Compared with Zigbee, the mass production of BLE chipsets reduces the cost of ICs.
Zigbee’s demand for gateways further increases the cost of the entire system. A BLE-based system can also provide limited functions (all functions except Internet connection) without the need for a gateway. Therefore, if we think that the software cost of the two is negligible, the BLE-based Bluetooth Mesh will score higher on the cost advantage. In addition, Zigbee’s license is more expensive and more complicated than BLE.
2. 10 interconnection
Almost all applications need to connect nodes to the Internet. In a BLE-based Bluetooth Mesh and Zigbee system, in order to control and monitor the device nodes in the Mesh network, we need an edge gateway device that converts Bluetooth Mesh or Zigbee data packets into IP network data packets and vice versa.
However, the Zigbee remote can also be used to control Zigbee nodes locally, but compared with smartphones, smartphones are ubiquitous devices, most of which have built-in BLE. Bluetooth Mesh is a software stack, so it can easily implement a complete Bluetooth Mesh protocol on existing smartphones, and directly control BLE-based Bluetooth Mesh devices without using any gateway for a temporary connection.
Therefore, for applications that do not have an edge gateway, Bluetooth Mesh provides a more friendly and rich experience. For cloud connection, if the user is near the Bluetooth Mesh network, the smartphone can be used as a temporary gateway device. However, for a complete Internet of Things connection and Internet (or cloud) control, a gateway is required in both Bluetooth Mesh and Zigbee-based systems.
3. Conclusion of Comparison of Bluetooth Mesh and ZigBee
From the above description, we can objectively see that the basic performance of Bluetooth Mesh and Zigbee are comparable.
With its simpler routing mechanism, Bluetooth Mesh is more suitable for mobile nodes, because the Zigbee routing protocol will bring more network overhead for maintaining the routing table of highly mobile nodes. Therefore, before choosing a technology implementation, the usage scenario must be considered.
Lower hardware cost, stable protocol stack in popular OS implementation, and smartphone control are the main advantages of Bluetooth Mesh over Zigbee. Since Zigbee entered this market field earlier, it currently has a larger ecosystem of in-home networks and Industrial Internet of Things (IIoT) systems. However, as a software-based solution on top of the existing BLE stack, Bluetooth Mesh can quickly catch up in the near future.
At present, in the consumer field, we have seen the ecological industry chain of Tmall Elf using Bluetooth Mesh as the communication technology gradually matures and has a very large industrial scale. Bluetooth Mesh will become Zigbee’s strongest competitor in the field of IoT systems in the future.
First of all, Bluetooth has a very large cost advantage. That’s because it uses the same hardware as Bluetooth Low Energy. Using the same silicon wafer means that more quantities of the same hardware can be produced, thereby reducing the unit price.
Secondly, Bluetooth focuses on meeting the needs of smart lighting. This is the most mature application of low-power wireless mesh networks. It also supports beacons. In addition to traditional smart homes, it can also achieve more application scenarios, such as asset positioning, Indoor positioning, and navigation.
Finally, almost all smartphones support BLE, and Bluetooth has the best brand recognition in standard formulation, and its interconnection capabilities are better than Zigbee, which makes it an advantage in consumer applications.
Above, Bluetooth Mesh-based on BLE can realize more value and applications in the field of future Internet of Things, especially in the field of commercial lighting, using lighting as a platform.