1 INTRODUCTION  
1.1 Scope and Contribution  

2 RESEARCH METHODOLOGY  
2.1 Research Goals Formulation  
2.2 Search Strategy  
2.3 Inclusion and Exclusion Criteria  

3 AN OVERVIEW OF FEDERATED LEARNING IN EDGE COMPUTING  
3.1 Background  
3.2 FL Characteristics Specific to Edge Computing  
3.3 FL Challenges and Solutions in Edge Network Topologies  
3.4 Categorization of Topology-aware FL in Edge Computing  

4 TYPES OF FL NETWORK TOPOLOGY  
4.1 Star Topology  
4.2 Tree Topology  
4.3 Decentralized/Mesh Topology  
4.4 Minor Topologies  

5 CHALLENGES AND FUTURE RESEARCH ROADMAPS  
5.1 Topology Selection  
5.2 Communication Cost  
5.3 Client-drift  
5.4 Ethical/Privacy Concerns  
5.5 Availability-aware FL Assisted by Topology Overlay  
5.6 Conduct Real-world Deployment  

6 CONCLUSION