# Computing Communications Channel Capacity

Check out our Virtual Training on Evaluating Communications Links on June 28

Channel Capacity* is the tight upper bound on the (data) rate at which information can be reliably transmitted over a communications channel. STK doesn’t compute this through its Data Providers, but it can be computed by making use of the Calculation Tool within the Analysis WorkBench functionality. Where C = Capacity in Megabits per second B = Bandwidth in MHz S/N is Signal to Noise Ratio and can be interchanged C/N which is a power ratio (not in dB). Here are the steps used to create the formula using Calculation Tool:
1. Create a Data Element for C/N from the Link Information Data Provider for an access between a transmitter and receiver.
2. Convert C/N from dB and add one to form result: R = (1+C/N)
3. Use the binary logarithmic single variable function to form result: L = log2(R)
4. Create a Data Element for Bandwidth (B) from the Link Information Data Provider for an access between a transmitter and receiver.
5. Use a multiplication two variable function to form result: Capacity = B x L
Use this Capacity Scalar Calculation to create a Figure of Merit for a Coverage between a transmitter Asset and receiver Grid Object or a receiver Asset and transmitter Grid Object. If you’d like to see where the formula came from, check out the following:

Where C = Capacity in Megabits per second

B = Bandwidth in MHz

S/N is Signal to Noise Ratio and can be interchanged C/N which is a power ratio (not in dB). Here are the steps used to create the formula using Calculation Tool: 1) Create a Data Element for C/N from the Link Information Data Provider for an access between a transmitter and receiver. 2) Convert C/N from dB and add one to form result: R = (1+C/N) 3) Use the binary logarithmic single variable function to form result: L = log2(R) 4) Create a Data Element for Bandwidth (B) from the Link Information Data Provider for an access between a transmitter and receiver. 5) Use a multiplication two variable function to form result: Capacity = B x L Use this Capacity Scalar Calculation to create a Figure of Merit for a Coverage between a transmitter Asset and receiver Grid Object or a receiver Asset and transmitter Grid Object.
Posted: 6/13/2016 11:00:15 AM