Bluetooth protocol is not much encouraged for long duration applications due to power consumption limitations. Hence, for small gadgets which run on battery or limited power source, a new wireless data transfer protocol was needed which could manage working with low power consumption. To fulfill these requirements, a protocol named Zigbee was announced just at the time when Bluetooth was getting popular i.e. in 1999. However, Zigbee caught attention for commercial applications around 2005.
Interestingly, these ISM band using protocols, Bluetooth and Zigbee, though defined in the same IEEE specification of 802.15, are very dissimilar at various grounds. This article will detail with some of the common and uncommon differences between bluetooth and zigbee protocols.
1. Origin: Bluetooth was launched in the year 1994 by German telecom giant Ericsson while Zigbee was devised in the year 1998. The name Bluetooth has been derived from popular European unification king, Harald Blatand while Zigbee gets its name from the dance movements of a honeybee.
2. IEEE Standards: Bluetooth, though not under IEEE now, was defined under 802.15.1 standard while Zigbee is defined under IEEE 802.15.4 standard.
3. Management Alliances: Zigbee is managed by Zigbee Alliance which tests and certifies Zigbee based devices. All Zigbee based protocols get standardized under IEEE. On the other hands, Bluetooth is managed for standards and device by a single body: Bluetooth SIG (Special Interest Group).
4. Protocol Updates: Bluetooth has been updated under version 2.0, 2.1, 3.0, 4.0 etc while Zigbee received updates in 2004, 2006 and 2007. Now Zigbee exists in two types: Zigbee and Zigbee Pro which are different in terms of addressing algorithms.
5. Frequency: Bluetooth works under 2.4 GHz while Wi-Fi works at 868 MHz, 915 MHz and 2.4 MHz frequencies.
6. Channel Bandwidth: Bluetooth based channel consume bandwidths upto 1MHz while Zigbee based networks consume bandwidths of 0.3MHz, 0.6 MHz and 2 MHz depending upon the frequency at which networks are communicating.
7. Type of Computer Network: Zigbee has been designed to communicate under Personal Area Network whereas Bluetooth based communication serves for Wide PAN (WPAN).
8. Maximum number of cell nodes: In Bluetooth, upto 8 cell nodes can be connected to each other while in Zigbee more than 65,000 cell nodes can be connected together.
9. Range: Bluetooth based networks can exist upto 10m, while Wi-Fi based networks can exist from 10-100meters.
10. Self Healing Networks: Self Healing networks are those where networking is not disturbed if one node gets damaged. In self healing networks, the nodes neighboring the damaged node will create a reverting loop, thus preventing any information to be sent to the damaged/non working node. This keeps the network up and makes it more stable.
Zigbee based systems are inherently known to keep up with self-healing network technology while Bluetooth doesn’t have this technology defined in it, though adaptations and research are being made for this.
11. Network Topologies: Bluetooth network can be established in a point to point master-slave method, master and upto 7 slave piconet networks and scatter net (linking two or more piconets).
On the other hand, Zigbee devices can be networked in star, mesh and other generic topologies. Various Zigbee based network topologies can be connected to each other in form of a cluster. Any Zigbee network would have three types of nodes: Zigbee Coordinator, Zigbee Router andZigbee Endpoint.
12. DataTransfer Rates: Bluetooth based networks have maximum data transfer rates of upto 1Mbps while in Zigbee, data transfer rates are upto 250Kbps.
13. Spread Spectrum Techniques: Spread Spectrum techniques count for the processes through which a signal is spread over frequency domain.This is done so as to accommodate more signals, increase signal security, reduce signal interference etc. Almost all wireless network protocols have defined some type of spread spectrum technique.
Bluetooth works on Frequency Hopping Spread Spectrum technique while Zigbee uses Direct Spread Spectrum technique. In Frequency hopping, the carrier signal is made to vary in terms of frequencies while in direct spread spectrum; the original signal is mixed and extracted from a pseudo random code at transmitter and receiver, respectively.
14. Energy Consumption: For any network, power consumption depends on the type of data being exchanged, distance between transmitter and receiver, desired power to be retained by signal and other factors.
Bluetooth is a protocol known for exchanging almost all types of data such as text, multimedia. On the contrast, Zigbee protocol is precisely for operational instructions and not much variety of data is known to be exchanged using it.
Obviously, Zigbee consumes significantly less power than its Bluetooth counterpart. Usually, Zigbee devices are 2.5-3 times more efficient than those working at Bluetooth.
15. Applications: Zigbee based systems are designed for wireless networking among sensors and is more preferred for devices which are smaller in size and consume less energy. TV remote controls, SCADA system sensor, medical instruments etc. are some areas where Zigbee based networking are done.
Bluetooth based applications are primarily in computer peripherals such as wireless keyboards, mouse, headsets etc. Also, some wireless remotes or gesture controlled gadgets use Bluetooth to exchange data.
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