边缘训练模型 Edge server DNN to be Gradient update trained Gradient can be compressed or sen infrequently Gradient update End device End device (b)Decentralized training. (a)Centralized training. ·集中式训练：Each worker computes local data set,which are then collected by a central parameter server,and the updates sent back to the workers.代表性模型：联邦学习 ·分布式训练：Each device computes its own gradient updates based on its training data and then communicates its updates to some of the other devices. ·两种模型比较：DNN模型一致性、带宽限制等。ƊŐŭʼnčŽ • Ʃ#Äŭʼn: Each worker computes local data set, which are then collected by a central parameter server, and the updates sent back to the workers. 8ţÓčŽŖƚŸ) • Z·Äŭʼn: Each device computes its own gradient updates based on its training data and then communicates its updates to some of the other devices. • !ĻčŽĒƆDNNčŽśÓ¹§Ƨ`Ł