“…Literature in FL cost optimization mainly focused on learning time and on-device energy consumption in mobile edge networks. The optimization of learning time was studied in [8], [27]- [33], and joint optimization for learning time and energy consumption was considered in [34]- [37]. These works considered resource (e.g., transmission power, communication bandwidth, and CPU frequency) allocation (e.g., [27], [28], [34]- [37]), cost-aware client selection (e.g., [29], [30]), client scheduling (e.g., [31]- [33]), and model pruning [8] for prespecified (i.e., non-optimized) design parameters (K and E in our case) of the FL algorithm.…”