What is the expected range of a 5G millimeter wave small cell in an urban environment?

The expected range of a 5G mmWave small cell in an urban environment depends on the deployment scenario and link conditions: (1) Line-of-sight (LOS): with a clear, unobstructed path between the gNB and UE. Range: 200-400 m (depending on gNB EIRP and UE antenna gain). At 200 m (28 GHz): free-space path loss = 20×log10(4×pi×200/0.0107) = 107.5 dB. With gNB EIRP = +60 dBm (typical for a 256-element phased array at a small cell) and UE NF = 6 dB: received power = +60 - 107.5 = -47.5 dBm. Required SNR for 256-QAM (peak rate): 25 dB. Noise power (100 MHz BW): -174 + 10×log10(100e6) + 6 = -88 dBm. Available SNR: -47.5 - (-88) = 40.5 dB. This provides significant margin (40.5 > 25 dB): 256-QAM is easily supported. At 400 m: FSPL = 113.5 dB. Received power = -53.5 dBm. Available SNR = 34.5 dB (still adequate for 256-QAM). (2) Non-line-of-sight (NLOS): in urban environments, most UEs are NLOS to the gNB. NLOS propagation at mmWave relies on reflections (from buildings, vehicles, signs) and diffraction (around building corners). Additional NLOS loss: 15-30 dB beyond FSPL (the reflected/diffracted path is longer and weaker). Effective range (NLOS): 100-200 m. At 150 m NLOS (28 GHz): total path loss ≈ FSPL (104 dB) + NLOS loss (20 dB) = 124 dB. Received power = +60 - 124 = -64 dBm. Available SNR = -64 - (-88) = 24 dB. This supports 64-QAM (not 256-QAM). Data rate at 64-QAM, 100 MHz, 4 MIMO layers: approximately 1.5 Gbps. (3) Coverage area: for a street-level small cell mounted at 5-10 m height on a lamppost or building facade: the coverage extends approximately 100-200 m along the street (NLOS + reflections from building walls). Cross-street coverage is very limited (the signal does not penetrate buildings at 28 GHz: building penetration loss = 20-40 dB for exterior walls). Inter-site distance (ISD) for continuous coverage: 150-300 m (requiring many small cells per km²).