In most of the books authors write that WSN has narrow bandwidth but what exactly the size of bandwidth in WSN? How much bandwidth is required for different WSN applications?
Typical WSN nodes that operate in 2.4GHz band are built upon 802.15.4 protocol using 5 MHz channels and therefore able to transmit up to 250 Kbps (http://www.digi.com/pdf/wp_zigbee.pdf) - enough for monitoring of sensor data and control of corresponding actuators. In the case of data rich applications other protocols could be used. Difficult radio communication situations could be resolved using lower frequencies as 433 or 868MHz - so called ISM bands.
Typical WSN nodes that operate in 2.4GHz band are built upon 802.15.4 protocol using 5 MHz channels and therefore able to transmit up to 250 Kbps (http://www.digi.com/pdf/wp_zigbee.pdf) - enough for monitoring of sensor data and control of corresponding actuators. In the case of data rich applications other protocols could be used. Difficult radio communication situations could be resolved using lower frequencies as 433 or 868MHz - so called ISM bands.
Bandwidth depends on the amount of data you take from sensors. A typical WSN would need at least 250KBps. Zigbee would be an ideal solution. However if your WSN require more bandwidth, if you are reading heavy data, it would be better to use wifi or other technologies. Bandwidth also depends on he spread of the network. Because routers have to handle many sensors simultaneously.
Data rate requirements depend upon the kind of information that you want to send, how often will you send it and how many nodes are using the same channel for transmission. For instance, variables such as temperature, humidity, vibrations, require few bytes to be transmitted. Other types of information, such as sound or video will require higher data rates.
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