Prerequisites & Notation

Before This Chapter

Chapter 17 shifts from "given a RIS, how do we use it?" (the theme of Chapters 5–15) to "where do we put it?" The underlying physics is the product path loss from Chapter 1: the two-hop BS-RIS-UE link scales as $d_1^2 d_2^2$ , which has strong implications for where the RIS belongs. Network planning familiarity is assumed but not deep cellular-RAN experience.

Notation for This Chapter

Deployment-specific notation. Distances dominate; angles are secondary.

Symbol	Meaning	Introduced
$d_1$	BS-to-RIS distance (m)
$d_2$	RIS-to-UE distance (m)
$d_0$	BS-to-UE direct distance (m)
$L$	Total cost of deployment ($)
$C_{\text{RIS}}$	Cost of a single RIS panel ($)
$C_{\text{relay}}$	Cost of an active relay or small cell ($)
$\lambda_{\text{RIS}}$	RIS panel density (panels/km²)
$p_{\text{cov}}$	Coverage probability
$\Omega$	Deployment region (2D polygon)

← Ch 16 Optimal RIS Placement