Abstract: As per the rapid growth of IoT devices and smart city services, there are new demands regarding data management systems. These autonomous systems need better infrastructure to handle real-time data. As per current technology standards, 5G wireless provides very fast speed and can connect one million devices in one square kilometer area. Regarding smart cities, this technology offers major changes due to its quick response time and high data capacity. This study checks how 5G affects city data systems as per a mixed approach using literature review, performance tests, network simulations, and three case studies. The research covers three international cities regarding 5G implementation - Seoul, Singapore, and Barcelona. Basically, 5G reduces delay by over 90% to 1-5 ms and increases speed by 100 times to 10+ Gbps, which is the same as enabling real-time data processing and continuous high-volume sensor data transfer. The mmWave technology in 5G networks surely provides high speeds, but it also causes high path loss. Moreover, this path loss happens because mmWave signals weaken quickly when they travel through the air. Basically, radio frequency propagation models help determine signal strength, coverage area, and outage probability by providing the same essential information about signal path loss and fading through theoretical or practical methods. A new method actually combines edge computing with federated learning to spread out data work in smart cities. This approach definitely helps process information locally instead of sending everything to one central place. Technology surely helps cities use data for better governance, but strong cybersecurity systems are needed to protect information. Moreover, city planners must design these systems keeping citizens at the center to ensure everyone gets equal access and prevent data theft. As per this analysis, technology can change how cities manage data, but there are problems regarding scalability, security, and system integration that need more research.

Keywords: 5G, Edge computing, IoT, MIMO (Multiple-Input Multiple-Output), Millimeter wave (mmWave) transmission, Ultra-Reliable Low Latency Communication (URLLC), Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC).

Downloads: | DOI: 10.17148/IARJSET.2025.12933