# Performance Analysis of P2P Networks with Light Communication Links: The Static Managed Case
## 4 LiFi- and WiFi-Based Communication P2P Architectures  
Having explained the potential of centralized and decentralized structures, this section describes the details and characteristics when these structures are analyzed with the parameters of LiFi 2.0 and WiFi 7, stressing that the use of LiFi applications is not usually straightforward nor the connections are usually direct as in the case of WiFi, considering node alignment, power and reflections of the signal, transmission and reception angles, and even electronic limitations. In this regard, this work makes an important contribution by proposing network architectures to allow the concept of P2P-LiFi to be really useful in the efficient distribution of information. Further, this research presents the visualization, practical approach, simulation, and implementation proposal of LiFi networks for static node environments (classrooms, museums, offices, control systems, and storage systems, among others) through a formal evaluation and quantitative values that allow for the comparison of LiFi-based technology with WiFi in centralized and distributed structures, to clearly define the cases in which one scenario is better than another. In detail, LiFi prototypes in general behave like Lambertian sources with a determined _field of view (FOV)_ and a _LOS_ between the optical emitter and receiver, as described in Figure 3. However, there are scenarios in which due to phenomena such as reflections or scattering, LiFi can act as a non-Lambertian source (\(NLOS\) propagation mode), as depicted in Figure 4, where the light beams corresponding to the emitter and the receiver constitute an overlapping volume through their _FOVs_[35]. In this regard, LiFi 2.0 is a constantly growing technology that can coexist with current and future RF technologies, providing extra capacity to offload traffic and reducing latency for critical applications. Due to its features and utilities, LiFi 2.0 has been considered as a complement to radio frequency technologies in scenarios that can provide solutions in fields like IoT, artificial intelligence (AI), big data, or vehicle communications, where hundreds of nodes are placed in a small region, generating high traffic rates that may cause congestion and high packet loss probability under RF transmissions that are usually omnidirectional [36; 37]. In contrast, LiFi communications comprise a much more restricted coverage area that allows for communication among a reduced number of nodes, which can improve the system's performance. However, there has not been an extensive study where both technologies are evaluated and analyzed. Indeed, we believe that LiFi cannot only complement WiFi networks but rather has certain characteristics that provide better performance than RF-based systems. Figure 3: LiFi 2.0 prototype in LOS propagation mode used for VL and IR spectrum. LiFi networks can use the whole spectrum of light, going through infrared, visible, and ultraviolet lengths. Generally, the first two ranges of spectra behave like Lambertian sources, then they require LOS propagation, opposite to the ultraviolet range, which is commonly used in NLOS propagation modes. In Figure 5, we show a P2P-LiFi LOS connectivity scenario, in which LOS propagation is needed to connect with the pairs of adjacent nodes that are in the north, south, east, and west positions (if it is applicable). Another architecture of P2P-LiFi with NLOS conditions is shown in Figure 6 where data are transmitted in one sense between adjacent levels, assuming that the first seed in the network (level 0) is in charge of distributing information through the nodes that it can reach, i.e., nodes in level 1, and so forth. Note that nodes in the same level can share chunks among them. Figure 4: LiFi 2.0 prototype in NLOS propagation mode used for UV spectrum. Figure 5: P2P-LiFi propagation scenario: a node (green) can download or upload information with its adjacent nodes (blue) in the cardinal points through their LOS and not with nodes that are out of range (gray).