Communication Efficient Decentralized Learning Over Bipartite Graphs

Chaouki Ben Issaid (1) , Anis Elgabli (1) , Jihong Park (2) , Mehdi Bennis (1) , Merouane Debbah (3, 4)

1 CWC - Centre for Wireless Communications [University of Oulu]
2 Deakin University, Burwood, Australia
3 CentraleSupélec
4 Masdar Institute of Science and Technology [Abu Dhabi]

In this paper, we propose a communication-efficiently decentralized machine learning framework that solves a consensus optimization problem defined over a network of inter-connected workers. The proposed algorithm, Censored and Quantized Generalized GADMM (CQ-GGADMM), leverages the worker grouping and decentralized learning ideas of Group Alternating Direction Method of Multipliers (GADMM), and pushes the frontier in communication efficiency by extending its applicability to generalized network topologies, while incorporating link censoring for negligible updates after quantization. We theoretically prove that CQ-GGADMM achieves the linear convergence rate when the local objective functions are strongly convex under some mild assumptions. Numerical simulations corroborate that CQ-GGADMM exhibits higher communication efficiency in terms of the number of communication rounds and transmit energy consumption without compromising the accuracy and convergence speed, compared to the censored decentralized ADMM, and the worker grouping method of GADMM.

Domains: Engineering Sciences [physics]

Chaouki Ben Issaid, Anis Elgabli, Jihong Park, Mehdi Bennis, Merouane Debbah. Communication Efficient Decentralized Learning Over Bipartite Graphs. IEEE Transactions on Wireless Communications, 2021, pp.1-1. ⟨10.1109/TWC.2021.3126859⟩. ⟨hal-03448311⟩