“…We note that the ITU standard of 5G uplink user experienced data rate is only 50 Mb/s [44], and even the 6G uplink user experienced data rate at Gbit/s level may not sufficiently support such huge uploading requirements of regular FL. Additionally, to our best knowledge, existing works on improving FL efficiency (such as FedAvg [4], sparsification [45], [46] and quantization [47], [48] with or without error feedback [49], [50], federated distillation [51]- [53], pruning [54], [55] or partially trainable network [56], [57], and over-the-air computation [58]- [60]) still consider the transmission of gradient updates and can achieve a relatively limited reduction in payload and experience degradation in performance. For instance, the payload reduction is of only two orders of magnitude of the original payload on the same CIFAR-10 dataset [61], [62].…”