AT&T Spectrum
n77 / C-band: phased deployment as FAA cleared airspace. n5 / 850 MHz: low-band coverage. n3 / DAS-style mmWave (n260 / n261) in select metro hotspots. n2 PCS 1900 MHz refarmed.
AT&T Architecture
Mix of Ericsson, Nokia, and increasingly cloud-native components. Strong push toward Open Fronthaul (O-RAN) but transition mid-execution.
PHY-Level Considerations
EN-DC dominant during transition; SA migration ongoing. Inter-band CA between C-band and low-band common. n5 cell-edge users handed-off to LTE for coverage.
Throughput Reality
Peak C-band: 1.0-1.5 Gbps DL. Typical: 200-500 Mbps. Low-band n5: 100-300 Mbps DL but exceptional coverage range.
Engineer Skills Profile
Multi-vendor RAN tuning (Ericsson + Nokia), inter-RAT mobility (LTE-NR), multi-band CA, AT&T-specific KPI conventions, Open Fronthaul understanding for O-RAN transition.
Common Engineering Issues
n77 vs n5 handover tuning at sector boundaries, ENM-NetAct workflow when working multi-vendor, FAA-related n77 power restrictions in airspace zones, large RAN footprint optimization.