link connection uses LTE instead of 5G, but it should not be a problem for mobile broadband services. Dual connectivity requires that 5G uplink control channels be optimized for maximum coverage. 10.7 Massive MIMO and Beamforming Algorithms Table 10.17 Benchmarking of uplink coverage solutions. Minimum Architecture Solution Description latency (ms) option LTE for uplink user Option 3x connectivity plane. 5G control plane at 3.5 GHz. Low band 5G 5G uplink and Option 2 and downlink at low Option 3x band. Supplemental 5G uplink at low Option 2 and uplink band. Option 3x When new 5G services are required with the 5G core network, then the Option 2 Standalone architecture will be utilized. Dual connectivity is not available with Option 2, and low band 5G will be needed. Low band 5G can be aggregated with 3.5 GHz for high capacity and data rates. The supplemental uplink is one option for uplink coverage, but the practical gain over dual connectivity is not obvious, and there are some challenges for the supplemental uplink transmission when LTE and 5G share the same frequency. The benchmarking of uplink coverage solutions are shown in Table 10.17. Massive MIMO and Beamforming Algorithms Massive MIMO is a major booster in radio performance. This section discusses some of the design factors that have an impact on massive MIMO benefits: antenna configura- tions, beamforming algorithms, and network functionality split. 10.7.1 Antenna Configuration The main parameters defining the massive MIMO antenna configuration are the number of antenna elements, also known as physical antenna elements, and the number of transceivers (TRX), also known as logical antenna elements. The number of antenna elements defines the physical size of the antenna and the antenna gain, which is relevant for coverage. The typical antenna configuration at the 3.5 GHz band has 192 antenna elements with 12 rows in the vertical direction, 8 columns in the horizontal direction, and cross-polarization. The antenna element spacing is typically half wavelength