With the proliferation of 5G and developments of 6G technologies already underway, understanding the real-world performance of various 5G enhancements such as higher modulation, beamforming, and MIMO of deployed 5G over 4G is vital. This work addresses this knowledge gap by conducting extensive 4G/5G measurements in low- (<1 GHz) and mid-bands (1 to 6 GHz) across Chicago and Minneapolis. As both 4G and 5G utilize low- and mid-band channels, we carefully analyze their performance and signal parameters to reveal several key observations: (i) 5G’s throughput improvement today is mainly driven by wider channel bandwidth in the mid-bands, from both single channels and channel aggregation, (ii) realizing further throughput gains necessitates better signal conditions achievable through denser deployment and/or beamforming, (iii) channel rank analysis shows real-world channel conditions rarely support the full 4×4 MIMO, (iv) advanced features like MU-MIMO and higher order modulation like 1024-QAM have yet to be widely deployed, and (v) aggregated throughput performance in LTE can be enhanced by incorporating shared and unlicensed bands, resulting in a performance similar to single-channel NR. These observations and conclusions suggest that the next generation of cellular systems should prioritize wider channels, possibly with enhanced channel aggregation, and a denser deployment architecture utilizing more beams. This would ensure consistently better signal strength across the coverage area with up to 4 MIMO layers per user.
