5G rollout challenges:

Cost and scalability: 5G requires a significant infrastructure upgrade due to the deployment of new base stations and small cell networks. 

Interference and Signal Propagation: 5G higher-frequency bands have shorter wavelengths, resulting in reduced signal propagation compared to previous generations, and obstruction by obstacles like buildings and foliage. Hence, 5G requires the deployment of more antennas to maintain signal quality.

6G vs. 5G: superior performance, even more challenging deployment

     6G is expected to offer up to 1,000x higher data transfer speeds compared to 5G:  terabits per second (Tbps) vs. gigabits per second (Gbps).

     Accordingly, 6G is expected to use 10x-100x higher frequency bands, hence exacerbating the interference and signal propagation challenges.