Deterministic vs.stochastic models Models are defined stochastic or statistical if only statistics of propagation parameters Ex:Mean path loss vs.distance are provided on the base of a generic Standard dev.of the fading environment description.Simple and fast On the opposite models are defined deterministic if the actual values of Ex:Actual path loss in a given propagation parameters are provided for a env.Many other parameters... specific environment.A detailed description of the environment is required.Complex and CPU time consuming In the future detailed environment databases and high-power computation will be cheap>deterministic modelling will be more and more popular Similarity with GPS navigators for cars 13
13 Deterministic vs. stochastic models In the future detailed environment databases and high-power computation will be cheap deterministic modelling will be more and more popular Similarity with GPS navigators for cars • Models are defined stochastic or statistical if only statistics of propagation parameters are provided on the base of a generic environment description. Simple and fast • On the opposite models are defined deterministic if the actual values of propagation parameters are provided for a specific environment. A detailed description of the environment is required. Complex and CPU time consuming Ex: Mean path loss vs. distance Standard dev. of the fading Ex: Actual path loss in a given env. Many other parameters …
Use of propagation models In the design phase of a wireless system,to properly design radio interface and system architecture In the deployment phase to guarantee coverage over the service area In the optimization phase to optimize the network and improve service quality Statistical models are more general and concise,and are mainly used in the design phase Deterministic models are more site-specific and accurate and are mainly used in the deployment phase. Nowadays advanced deterministic models are also used as study tools in the design phase 14
14 Use of propagation models • In the design phase of a wireless system, to properly design radio interface and system architecture • In the deployment phase to guarantee coverage over the service area • In the optimization phase to optimize the network and improve service quality • Statistical models are more general and concise, and are mainly used in the design phase • Deterministic models are more site-specific and accurate and are mainly used in the deployment phase. • Nowadays advanced deterministic models are also used as study tools in the design phase