# Zigbee spectrum calculation

I have information related to the wired network topology in a room with the dimensions 50x10x20m. This includes the virtual link information containing source, target and datarate on a particular link. Based on this information, I calculated the overall bandwidth as the sum of all the datarates on all the links in the network. Let's say this value is $1000 MHz$.

As a part converting the above wired topology to wireless using Zigbee, I intend to calculate the bandwidth when using Zigbee in the network. For this, I have removed all the multiple point to point links from the wired setup and ensured that using just one link from each device in the Zigbee network (since wireless is inherently multicast).

For the bandwidth calculation of the Zigbee network, I have used all the datarates of the wireless links and multiply them with the coding factor (which is 8 in 802.15.4's case) and sum all the datarates after multiplication with the coding factor. Doing this gives me $500 Mhz$. (Note that this is without implementing any scheduling which would be done later. It is just to get a raw idea on how much reduction in bandwidth I may expect)

I would like to know if the above method is correct when calculating the bandwidth for the wireless case.

If this is right, in case I intend to use 802.11g instead of Zigbee, how should I go about in calculating the coding factor for the 802.11g case?

• Please clarify your first paragraph. If you add datarates you get a datarate, measured in bits/sec, not a bandwidth, which is measured in Hz. – MBaz Sep 15 '16 at 14:09
• From this answer which says "Assuming that what you have now resembles a weight matrix W W , where the weights are the transmission rates of each link, then, the total bandwidth is simply the sum of all entries of W W .", I added the transmission rates. – smyslov Sep 15 '16 at 14:13
• It is common in networking, but incorrect, to equate bandwidth and data rate. – MBaz Sep 15 '16 at 14:42
• From the same answer, I think that Network Throughput will be a better metric in judging the impact of implementing a network over different wireless standards in this case as well, because there are many more factors that affect the data rate than just bandwidth. – A_A Sep 15 '16 at 15:49