# Performance of the 5 th Generation Indoor Wireless Technologies-Empirical Study
## 2 Materials and Methods
### Theoretical Performance of 5G and Wi-Fi 6 Links  
Calculating the throughput for both 5G New Radio (NR) and IEEE 802.11 ax single-user links can be done by using the formulas presented later in this section. These calculations are based on sets of parameters that are chosen to represent the desired radio configuration, and the outcome reflects the throughput that could be achieved with these parameters. However, it has to be noted that although we get a theoretical maximum throughput for the given parameter configuration, in practice, there are many limitations to how the parameters can be set, from the channel quality to the boundaries set by the regulators. The equation for calculating 5G NR throughput can be found in 3 GPP TS 38.306 [24]. The approximate data rate \(d\) (in Mbps) for a given number of aggregated carriers in a band is computed as  
\[d=10^{-6}\sum_{j=1}^{\mathrm{J}}\left((v_{\mathrm{layers}}^{j}Q_{m}^{j}f^{j} \mathrm{R}_{\mathrm{max}})(\frac{12N_{\mathrm{PRB}}^{\mathrm{BW}(j)\mu}}{T_{ \mathrm{S}}^{\mu}})(1-\mathrm{OH}^{j})\right), \tag{1}\]  
where J is the number of aggregated component carriers in a band or band combination. \(\mathrm{R}_{\mathrm{max}}=948/1024\), and for the \(j\)th component carrier, \(v_{\mathrm{layers}}^{j}\) is the maximum number of supported layers; \(Q_{m}^{j}\) is the maximum supported modulation order; \(f^{j}\) is the scaling factor, which can take the values 1, 0.8, 0.75, and 0.4; \(\mu\) is the numerology value defined in [25]; \(T_{\mathrm{S}}^{\mu}\) is the average orthogonal frequency-division multiplexing (OFDM) symbol duration in a subframe; \(N_{\mathrm{PRB}}^{\mathrm{BW}(j)\mu}\) is the maximum resource block (RB) allocation in bandwidth BW(\(j\)); and \(\mathrm{OH}^{j}\) is the overhead, which can take value 0.14, 0.18, 0.08, or 0.1, depending on the used frequency range. Full details on the calculation of the parameter values can be found in [24]. For IEEE 802.11 ax, the maximum link throughput formula can be found, for example in [26]:  
\[d=\mathrm{R}_{\mathrm{c}}\mathrm{log}_{2}(Q_{m})(\mathrm{N}_{\mathrm{data}}^{ \mathrm{BW}}t_{\mathrm{S}}\mathrm{N}_{\mathrm{SS}}) \tag{2}\]  
where \(\mathrm{R}_{\mathrm{c}}\) is the coding rate (maximum being 5/6), \(Q_{m}\) is the maximum supported modulation order, \(\mathrm{N}_{\mathrm{data}}^{\mathrm{BW}}\) is the number of data subcarriers as a function of bandwidth, \(t_{\mathrm{s}}\) is the time per OFDM symbol (13.6 \(\upmu\)s with 800 ns guard interval), and \(\mathrm{N}_{\mathrm{SS}}\) is the number of spatial streams ranging from 1 to 8. The maximum available modulation order and coding rate depend on the received signal strength, and vast majority of the other parameters have been set to certain values at the implementation phase. For the 5G, the parameters affecting the practical performance of a link are the available bandwidth, the number of supported spatial layers, and the slot format that defines the uplink/downlink (UL/DL) ratio of the data transmission. By assuming 40 MHz bandwidth at 3540 MHz carrier frequency, 256 quadrature amplitude modulation (QAM), 4 spatial layers, and 1/4 UL/DL ratio, we achieve a maximum throughput of 698 Mbps for DL and 186 Mbps for UL (total sum 884 Mbps), respectively. Similarly, the defining parameters for the Wi-Fi 6 link are the available bandwidth and the number of spatial streams. By assuming 40 MHz bandwidth in 5 GHz center frequency and assuming also four spatial layers and 256 QAM, we get a maximum throughput of 917 Mbps. From the above simple calculations, we can see that with alike parameters, both systems produce a comparable throughput. The practical throughput in the field depends on the two main factors: how much resources are available for the system and how well the system can utilize them. There are two major differences between the systems.