Transmitted power is a pivotal concern for Internet of Things (IoT) devices and other battery-constrained devices utilizing Wi-Fi connectivity. Such devices typically face stringent power limitations due to their compact size or dependence on batteries, which restrict the power available for signal transmission. This poses a significant challenge in striking a balance between conserving battery life and ensuring reliable communication. While increasing transmission power can enhance the range and reliability of communication, it also accelerates battery depletion. 

When the transmit power of an Access Point (AP) significantly exceeds that of a client device, it can lead to what is known as the "near-far" problem. In this scenario, the client can easily receive signals from the AP, but the AP may struggle to detect the client's signals, especially if it is located far away as shown in Fig. 1. This asymmetry can result in unreliable communication, as the AP may have trouble in acknowledging data packets sent by the client, leading to retransmissions and lower throughput. This mismatched AP-Client power levels in Wi-Fi networks can introduce several challenges that affect coverage, performance, and overall network efficiency. 

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To address these issues, it is essential to ensure that AP and client devices have appropriately matched transmit power levels. Simply lowering the AP’s transmit power can have several negative effects on other users in the vicinity. One of the primary impacts is reduced coverage, leading to potential dead zones or areas with poor connectivity. This can particularly affect users on the edges of the network, who may already be experiencing weaker signals. Another issue is increased interference. When an AP's transmit power is reduced, devices farther away may struggle to maintain a reliable connection, leading to excessive retransmissions and a corresponding increase in channel congestion. These devices might increase their transmit power in response, leading to a higher likelihood of interference with neighboring networks or devices operating on the same frequency. This interference can degrade the performance of nearby networks and reduce overall network capacity. Furthermore, reducing the AP's transmit power can also impact network throughput. Devices that were previously able to communicate with the AP at higher data rates may need to fall back to lower rates due to the weaker signal. This can result in slower overall network speeds and reduced quality of service for users. Balancing the transmit power levels to ensure adequate coverage while minimizing interference is key to maintaining a reliable and efficient Wi-Fi network. 

LATYS FOCUS, as a non-reciprocal Reconfigurable Intelligent Surface (RIS), offers a sophisticated solution to the near-far problem prevalent in Wi-Fi networks with mismatched AP-client power levels.

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In scenarios where the AP has a higher transmit power than the client, LATYS FOCUS can dynamically adjust the phase and amplitude of the incident signals to amplify the client's signal towards the AP as shown in Fig. 2. This adjustment effectively counteracts the near-far effect, ensuring that the AP receives the client's signals reliably. By intelligently manipulating the signal propagation, LATYS FOCUS helps maintain a balanced and efficient communication link, optimizing network performance and enhancing the user experience. 

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