Mesh topologies are used when network communication reliability is critical:

• Mesh topologies are frequently used by military organisations to avoid communication breakdowns.
• Cities are increasingly relying on wireless mesh networks to monitor traffic flow, sewage treatment, and street lighting control. Emergency services, such as police and fire departments, also rely on wireless mesh networks to ensure reliable communication.
• Some gas and electric utility companies use mesh networks to enable smart metres to send readings automatically.

Read More: Why do we use bus topology?