
FedClassAvg: Local Representation Learning for Personalized
Federated Learning on Heterogeneous Neural Networks
Jaehee Jang
hukla@snu.ac.kr
Department of Electrical and Computer Engineering
Seoul National University
Seoul, South Korea
Heonseok Ha
heonseok.ha@snu.ac.kr
Department of Electrical and Computer Engineering
Seoul National University
Seoul, South Korea
Dahuin Jung
annajung0625@snu.ac.kr
Department of Electrical and Computer Engineering
Seoul National University
Seoul, South Korea
Sungroh Yoon∗
sryoon@snu.ac.kr
Department of Electrical and Computer Engineering
Interdisciplinary Program in Articial Intelligence
Seoul National University
Seoul, South Korea
ABSTRACT
Personalized federated learning is aimed at allowing numerous
clients to train personalized models while participating in collabora-
tive training in a communication-ecient manner without exchang-
ing private data. However, many personalized federated learning
algorithms assume that clients have the same neural network archi-
tecture, and those for heterogeneous models remain understudied.
In this study, we propose a novel personalized federated learning
method called federated classier averaging (FedClassAvg). Deep
neural networks for supervised learning tasks consist of feature
extractor and classier layers. FedClassAvg aggregates classier
weights as an agreement on decision boundaries on feature spaces
so that clients with not independently and identically distributed
(non-iid) data can learn about scarce labels. In addition, local fea-
ture representation learning is applied to stabilize the decision
boundaries and improve the local feature extraction capabilities
for clients. While the existing methods require the collection of
auxiliary data or model weights to generate a counterpart, FedClas-
sAvg only requires clients to communicate with a couple of fully
connected layers, which is highly communication-ecient. More-
over, FedClassAvg does not require extra optimization problems
such as knowledge transfer, which requires intensive computation
overhead. We evaluated FedClassAvg through extensive experi-
ments and demonstrated it outperforms the current state-of-the-art
algorithms on heterogeneous personalized federated learning tasks.
∗Corresponding author
Permission to make digital or hard copies of all or part of this work for personal or
classroom use is granted without fee provided that copies are not made or distributed
for prot or commercial advantage and that copies bear this notice and the full citation
on the rst page. Copyrights for components of this work owned by others than ACM
must be honored. Abstracting with credit is permitted. To copy otherwise, or republish,
to post on servers or to redistribute to lists, requires prior specic permission and/or a
fee. Request permissions from permissions@acm.org.
ICPP ’22, August 29-September 1, 2022, Bordeaux, France
©2022 Association for Computing Machinery.
ACM ISBN 978-1-4503-9733-9/22/08. . . $15.00
https://doi.org/10.1145/3545008.3545073
CCS CONCEPTS
•Computing methodologies →Distributed articial intelli-
gence
;Computer vision tasks;Computer vision representations;Su-
pervised learning by classication.
KEYWORDS
Neural Networks, Federated Learning, Model Heterogeneity, Re-
source Constraint, Communication Ecient, Representation Learn-
ing
ACM Reference Format:
Jaehee Jang, Heonseok Ha, Dahuin Jung, and Sungroh Yoon. 2022. FedClas-
sAvg: Local Representation Learning for Personalized Federated Learning on
Heterogeneous Neural Networks. In 51st International Conference on Parallel
Processing (ICPP ’22), August 29-September 1, 2022, Bordeaux, France. ACM,
New York, NY, USA, 10 pages. https://doi.org/10.1145/3545008.3545073
1 INTRODUCTION
Federated learning is a privacy-preserving collaborative machine-
learning technique. It enables multiple clients and a global server
to train by exchanging knowledge from local training and the data
itself. Because the data distributions of clients are not independent
and identically distributed (non-iid), and conventional parallel ma-
chine learning algorithms assume iid data distributions of clients,
new algorithms are needed. Beginning with FedAvg [
21
], many
studies [
11
,
12
] have been proposed to improve the generalization
performance of federated learning algorithms. However, because
federated learning concentrates on improving the global model, the
client model performance for local data distribution deteriorates.
Therefore, the concept of personalized federated learning has
been proposed. It aims for the client to train personalized models
collaboratively while maintaining model performance on local data
distributions. Many personalized federated learning techniques [
16
,
23
] have signicantly contributed to addressing data heterogeneity
among clients. Most personalized federated learning algorithms
constrain all clients to use the same model architecture. However,
it is necessary for personalized federated learning to allow clients
to choose the dierent model architectures that are eective for
various data distributions of clients.
arXiv:2210.14226v2 [cs.LG] 27 Oct 2022