Minimum-Cost QoS-Constrained Deployment and Routing Policies for Wireless Relay Networks

Table 2

Notations of decision variables.

Notation	Description
Decision variables
𝜂𝑟𝑘	1 if candidate location 𝑟 is selected to build a RS with configuration 𝑘 and 0 otherwise
ℎ^dir𝑟𝑏	1 if RS 𝑟 associates with BS 𝑏 in direction dir and 0 otherwise
𝜅^dir𝑛𝑠	1 if node 𝑠 is selected to cooperatively relay the transmission of MC 𝑛 in direction dir and 0 otherwise, where 𝑠∈{𝑅∪𝐵}
𝑦^dir𝑛𝑢𝑣	1 if link 𝑢𝑣 is on the multicast tree adopted by MC 𝑛 in direction dir and 0 otherwise
𝑥^dir𝑛𝑟𝑝	1 if path 𝑝 is selected for MC 𝑛 to cooperative RS 𝑟 in direction dir and 0 otherwise, where 𝑝∈𝑃𝑏𝑟
Auxiliary variables
𝜙^dir𝑢𝑣	The SNR received by node 𝑣 in link 𝑢𝑣, where 𝑢,𝑣∈{𝑅∪𝐵}
𝜋^dir𝑢𝑣	The SNR received by node 𝑣 in link 𝑢𝑣, where 𝑢∈{𝑅∪𝐵},𝑣∈𝑁 in DL; and 𝑢∈𝑁,𝑣∈{𝑅∪𝐵} in UL
𝜔𝑛	The summation of SNR received by MC 𝑛 in DL
𝜀𝑛𝑠	The summation of SNR received by node 𝑠 in UL oriented by MC 𝑛, where 𝑠∈{𝑅∪𝐵}