 from $R_{i} $ for swapping with $\sigma _{k} $ at a next entanglement swapping period $\pi '_{S} $, defined as$\left|\bar{B}\left(R_{i} \left(\pi '_{S} \right),\sigma _{k} \right)\right|={\tfrac{\left|B\left(R_{i} \left(\pi '_{S} \right),\sigma _{k} \right)\right|}{\left|B_{R_{j} } \left(\pi _{S} \right)\right|}} 