ACM Reference Format:

1 INTRODUCTION

2 BACKGROUND
2.1 Human Activities
2.2 Sensors
2.3 Human Activity Recognition
2.4 Transfer Learning
2.5 Transfer Learning in Sensor-based HAR

3 TRANSFER LEARNING FOR HAR IN SMART HOME SCENARIOS
3.1 Heterogeneous Transfer
3.2 Difference in Tasks
3.3 Multi-source Transfer Learning
3.4 Personalized Transfer Learning
3.5 Optimal Source Selection

4 TRANSFER LEARNING FOR HAR USING WEARABLES
4.1 Heterogeneous Transfer
4.2 Personalized Transfer Learning
4.3 Multi-Source Transfer Learning
4.4 Difference in Tasks
4.5 Dynamic Environments
4.6 Distributed & Federated Learning
4.7 Performance Measurement

5 DISCUSSION
5.1 Review of the State-of-the-art
5.2 Roadmap for Future Work

6 CONCLUSION