Zigbee v/s Wi-Fi

Zigbee has often been regarded as a mini version of Wi-Fi. Keeping some features like range, power consumption apart, zigbee and wi-fi are often used in similar applications in terms of household based wireless communication. These short range wireless technologies even share common ISM band of 2.4GHz, use same spread spectrum technique. Interestingly, both of have been developed and proposed in a different mindset and hence some significant differences exist between these two. This article compares these two technologies on various grounds of technical and applicative scenarios. Keep on reading to find out the major differences between Zigbee and WiFi technologies.

Difference between Wi-Fi and Zigbee

1. IEEE Standard: Wi-Fi has been standardized under IEEE 802.11.x standard. There are several versions of the protocol where x gets replaced by a, b, g, n etc. which are different versions of Wi-Fi. Zigbee comes under 802.15.4 IEEE standard.

2. Caretaker Alliance: Wi-Fi is managed and its certification process is taken by Wi-Fi Alliance, an independent group constituted by several electronics and communication companies. On similar grounds, Zigbee also has a separate alliance that takes of Zigbee based product development and certification processes.

3. Development Timeline: The idea for Wi-Fi came out as an alternative to ease work of cashier machines in the year 1985. A community to standardize was established in the year 1990 which launched the standard in the year 1997.

On the other hand, idea was Zigbee was conceived in the year 1999, when it was found that for some long running applications, Wi-Fi and Bluetooth were not prepared. It was launched in the year 2004.

4. Operating Frequency: Wi-Fi is known to work at 2.4GHz, 5GHz, though there have been recent developments where Wi-Fi is working at 60GHz frequency. Zigbee, works at 900-928 MHz and 2.4GHz. Besides that Zigbee protocol has a specific frequency of 868 MHz for European countries.

5.Channel Bandwidth: Zigbee protocol based communications have a channel bandwidth of 1MHz while Wi-Fi channels have a bandwidth of 0.3, 0.6 or 2MHz.

6. Network Range: Zigbee is restricted to Wireless Personal Area Networks (WPAN), reaching 10-30meter in usual applications. Recently, there have been some applications which tend to reach 100m in terms of range. Wi-Fi serves up for PAN and WLAN area networks with an average range between 30 to 100 meters.

7. Data transfer speed: Wi-Fi networks, though faster than zigbee in terms of data transfer, show variation in terms of speed. Wi-Fi networks defined under 802.11b standard have maximum data transfer speed of 11mbps while a and c versions have 54mbps of maximum data transfer speed. Maximum speed in zigbee networks is only 250kbps, fairly low than the lowest Wi-Fi offers.

8. Bit Time: It can be defined as time taken to transmit one bit at a given data rate of transfer. Bit time in zigbee is 4micro seconds while in Wi-Fi it is only 0.00185 micro seconds.

9. Power Consumption: Wi-Fi, though now having a low power version over the horizon, has not been known as a power efficient network. Wi-Fi based devices need a good battery back-up if one wants to use them for more than 10hours or so. On the other hand, Zigbee protocol has been designed for “assemble and forget” manner. These are extremely minimal in terms of power consumption and hence can go on for weeks and months. In general, Zigbee based networks consume 1/4th of the power consumed by Wi-Fi networks.

10. Network Elements: In a standard point to point network, two stations can be connected to each other. A Wi-Fi router is also needed in some places where one needs to connect multiple devices to each other and/or wants to connect to the internet.

In Zigbee, the network elements can be broadly classified into three types: Zigbee coordinator, Zigbee end router, Zigbee end device.

11. Network Size: A single Wi-Fi based network can have a network size of up to 2007 nodes whereas Zigbee based networks can have over 65,000 nodes in one such network.

12.Network Security: Zigbee protocols use Advanced Encryption Security (AES) methods for encryption and CCB-CCM methods for network security. On the other hand, Wi-Fi based networks use WEP, WPA and WPA2 protocols for network encryption and security, respectively.

13. Applications: Wi-Fi is a preferable choice for internet connection based network and now is also encouraged to interface various media/entertainment devices wirelessly. One can find Wi-Fi in data exchange between a computer and modem, streaming music and videos on a television through a Wi-Fi enabled computer or media device.

Zigbee protocol has been precisely designed to exchange data and it is more prevalent in the wireless sensor based networks such as those in home automation systems or industrial machinery coordination systems.

Researches are being to bring down power requirements of Wi-Fi based systems so that they can perform at low energy levels like Zigbee does. Moreover, a smoother gateway between both protocols is also on its way for better interfaces between varieties of gadgets.