Fig. 2From: Distributed coalitional game for friendly jammer selection in ultra-dense networksA brief comparison between classical and stage combined spectrum leasing. \(P_{m}^{n_{m}}\) and \(P_{k}^{n_{m}}\) denote the transmission power of MUE m and jammer SBS k on channel n m , respectively. The words illustrate the operations of MUEs and SBSs in the corresponding stage while the shades of each box intuitively show the signal strength, e.g., the white box in a means a zero powerBack to article page