impact on modem power consumption. Interactive gaming applications can involve frequent transfer of small packets of data to give a real-time response, and if the update frequency falls within the inactivity timer period of the DRX cycle, the modem will be awake most of the time with increased power consumption. Updates from different applications, if their timing is not coordinated, would increase the proportion of DRX cycles in which the UE is active and thereby increase power consumption. 5.6.4 Antenna Design Considerations Large antenna arrays at the BS are necessary for 5G systems and in particular for operation in nmWave bands. Large number of antennas at the UE side are also expected to guarantee acceptable received signal levels for 5G services. As the number of antennas increases, it is advantageous to use 2D and 3D structures for the arrays. This reduces the required space and also enables spatial separation and beamforming in two or three dimensions. For exam- ple, a 64-element uniform linear array with an inter-element spacing of X/2 could occupy a horizontal span of 3 m at 2 GHz, which reduces to 1.5 m if dual-polarized antenna elements are utilized. In contrast an 4 dual-polarized array can be accommodated in a 0.6 m X 0.4 m space and can spatially resolve users and form beams in 3D space. Antenna New Radio Access RF and Transceiver Design Considerations 727 arrays may be arranged in a number of different ways, the most common architectures being uniform linear arrays, uniform rectangular arrays, uniform circular arrays, and stacked uni- form circular arrays. The system performance of these architectures is often measured in terms of beam gain and half-power beam-width both in azimuth and in elevation planes. For massive MIMO systems, it is important to capture as many degrees of freedom of the channel as possible with a high number of effective antennas. For compact antenna config- urations, this often leads to antenna structures that have shown to be effective for multi- dimensional channel charac