A telecommunication network associated with a wireless telecommunication provider can be configured to dynamically switch the primary cell (PCell) used by user equipment (UE) for carrier aggregation (CA) in 5G cellular networks. Instead of remaining anchored to an initially selected PCell, a different PCell may be dynamically selected based on different network conditions. The network conditions may include network congestion, network capacity, uplink speed, location of the UE, an activity of the UE (e.g., is the UE uploading or planning to upload data), and the like. As an example, the PCell may be selected from an n41 (2.5 GHz) cell and an n71 (600 MHz) cell. When the UE is close to the n41 cell, the n41 cell may be selected. When the UE is moving away from the cell center and toward the cell edge, the PCell may be switched from the n41 cell to the n71 cell.