Hello, can Shannon capacity be used to estimate the rate for all
wireless
technologies or just certain ones? I've been calculating channel
capacities for 802.16 and 802.11 fine, but 802.15.4 is really
confusing me. My data rates are an order of 10 times bigger. How do
you
calculate the capacity of an 802.15.4 channel?

Also, 802.15.4 specifies fixed data rates. But to me, logically, varying an amount of a physical layer resource, such as power or bandwidth, should vary your rate. How are 802.15.4 rates fixed? Doesn't the Shannon capacity prove that you can only fix a data rate by adjusting other physical layer properties to compensate?

Any guidance on this would be appreciated. To me using the shannon limit C = Wlog2(1 + P*G/(w*N + I)) should allow me to estimate the channel capacities for any technology considering their physical layer resource restrictions.

Thanks, Omar

Also, 802.15.4 specifies fixed data rates. But to me, logically, varying an amount of a physical layer resource, such as power or bandwidth, should vary your rate. How are 802.15.4 rates fixed? Doesn't the Shannon capacity prove that you can only fix a data rate by adjusting other physical layer properties to compensate?

Any guidance on this would be appreciated. To me using the shannon limit C = Wlog2(1 + P*G/(w*N + I)) should allow me to estimate the channel capacities for any technology considering their physical layer resource restrictions.

Thanks, Omar