More importantly, security capability trade-offbetween secondary and primary networks can be totally controlled with appropriate selection of systemparameters.  ...  primary informationagainst an eavesdropper and self-powering by harvesting radio frequency energy of primary signals.Security capability of both secondary and primary networks are analyzed in terms of secrecy  ...  The label "varepsilon" on the x axis is ε Figure 6 shows the SOPs w.r.t ε with parameters of Figure 2 excepting P t /N 0 = 10 dB.  ...