Question

TACSAT communications is a common way to receive network services while forward deployed. A tactical satellite terminal “pulls” services from a Strategic Tactical Entry Point (STEP) site via satellite transmission. These services are passed from the TACSAT terminal to tactical servers within the Brigade TOC (in this scenario) which in turn provides all SIPR services to the brigade equipment to include the Brigade Commander’s computer. For TACSAT SIPR services to be available, both satellite connections (STEP link and TACSAT link) as well as the tactical SIPR servers must be operational. However, these three events are dependent upon one another with the following known probabilities:

• The probability the TACSAT link and tactical servers are both operational given that the STEP link is not operational is 0.167.

• The probability the STEP link is not operational and the TACSAT link is operational is 0.02.

• The probability the TACSAT link and tactical servers are operational and the STEP link is not operational is 0.01.

• Given that the TACSAT link and tactical servers are both operational, the probability that the STEP link is operational is 0.9881.

• Given the STEP link and TACSAT links are both operational, the probability the tactical servers are operational is 0.9765

Calculate the probability of receiving TACSAT SIPR services to the Brigade TOC. Avoid rounding calculations until the end if possible.

Answer 1