B

Set of base stations (BSs) sites.

R

Set of relay stations (RSs) sites.

T

Set of User Equipment (UE) or users.

(b,r)

Denotes link between BS b and RS r.

(b,t)

Denotes link between BS b and UE t.

(r,t)

Denotes link between RS r and UE t.

\(c_{b}^{B}\)

Denotes BS cost at BS site b.

\(c_{r}^{R}\)

Denotes RS cost at RS site r.

\(l_{b,r}^{BR}\)

Denotes path loss associated with link (b,r).

\(l_{b,t}^{BT}\)

Denotes path loss associated with link (b,t).

\(l_{r,t}^{RT}\)

Denotes path loss associated with link (r,t).

\(m_{b,r}^{BR}\)

Represents upper bound (e.g., channel capacity) on the possible information


flow rate associated with the link (b,r).

\(m_{b,t}^{BT}\)

Represents upper bound (e.g., channel capacity) on the possible information


flow rate associated with the link (b,t).

\(m_{r,t}^{RT}\)

Represents upper bound (e.g., channel capacity) on the possible information


flow rate associated with the link (r,t).

\(u_{t}^{T}\)

Denotes traffic demand of UE t.

C_{1} and

Denotes the maximum capacity (in bits per second) for each

C_{2}

Deployed BS and RS, respectively.

W_{1} and

Weight parameters for two terms of objective function.

W_{2}
 
\(y_{b}^{B}\)

Denotes binary decision variables that determine


whether a BS b is deployed at BS site.

\(y_{r}^{R}\)

Denotes binary decision variables that determine


whether a RS r is deployed at RS site.

\(x_{b,r}^{BR}\)

Binary decision variables that denotes whether a connection


is established on corresponding links (b,r).

\(x_{b,t}^{BT}\)

Binary decision variables that denotes whether a connection


is established on corresponding links (b,t).

\(x_{r,t}^{RT}\)

Binary decision variables that denotes whether a connection


is established on corresponding links (r,t).
