In wireless communication systems like Wi-Fi, the data transmission rate is not fixed. It is dynamically adjusted based on the quality of the radio link, which is primarily determined by the Signal-to-Noise Ratio (SNR). As the signal strength (RSSI) decreases, assuming the noise floor remains constant, the SNR also decreases. To maintain a reliable connection in the presence of a lower SNR, the transmitting and receiving devices will negotiate a lower, more robust Modulation and Coding Scheme (MCS). This results in a decrease in the overall transmission speed (data rate) to reduce errors and retransmissions.

A. Noise: The ambient noise floor is a characteristic of the RF environment and the receiver's electronics; it is not dependent on the strength of the desired signal.

B. Interference: Interference is caused by other unwanted RF sources. The level of interference is independent of the desired signal's strength, although a weaker signal is more susceptible to it.

C. Latency: Latency is likely to increase, not decrease. Lower transmission speeds mean it takes longer to send a packet, and a lower SNR can lead to more retransmissions, both increasing delay.

1. Kurose, J. F., & Ross, K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.).

Reference: Chapter 7, Section 7.2.3, "IEEE 802.11 Wireless LANs". The text explains that as the SNR decreases, a wireless station will switch to a lower transmission rate that is more robust to noise, a process known as rate adaptation. A weaker signal directly contributes to a lower SNR.

2. Goldsmith, A. (2005). Wireless Communications. Cambridge University Press.

Reference: Chapter 9, "Adaptive Modulation and Coding". This chapter details the principle that the data rate of a wireless link can be adapted to the channel conditions (i.e., the SNR). Specifically, Figure 9.1 and the surrounding text illustrate that as SNR decreases, the system must switch to a lower-order modulation (e.g., from 64-QAM to QPSK), which corresponds to a lower data rate, to maintain a target bit-error rate.

3. MIT OpenCourseWare. (2011). 6.02 Introduction to EECS II: Digital Communication Systems, Fall 2011. Massachusetts Institute of Technology.

Reference: Lecture 15, "Wireless Communication". The lecture notes discuss the Shannon Capacity formula, C = B log₂(1 + SNR), where C is the channel capacity (maximum data rate). This formula mathematically demonstrates that as the signal power component of the SNR decreases, the maximum achievable data rate (C) also decreases.