Clear Channel Assessment (CCA) is an integral component of CSMA based Medium Access Control (MAC) protocols employing channel sensing during transmission. The channel sensing mechanism is a cross-layer scheme where CCA operates at the PHY layer, used on the transmitter and receiver side, impacting the MAC layer, including the node's energy consumption and overall throughput. This paper evaluates IEEE 802.15.4 standard-based MAC protocols for various traffic conditions. It proposes an adaptive CCA (A-CCA) timing mechanism to improve node energy consumption by reducing node time in false wakeups and idle-listening modes. ACCA helps transmitters to adjust their radio powers in high traffic and interference environments above the noise floor, allowing the receiver to monitor the sender signal and adjust its wakeup period accordingly. The proposed scheme was evaluated using Cooja Simulator as well as CC2420 based platforms to report improved node lifetime and reduce false wakeups under heavy interference. The proposed scheme reported (1.10% and 1.18%) reduction in radio duty cycle for light and heavy traffic environments. The results of the study indicated that ACCA improved the network power consumption, where an overall 6% power reduction is achieved to improve the node lifetime.

清晰通道评估（CCA）是基于CSMA的媒体访问控制（MAC）协议的组成部分，该协议在传输过程中采用了通道感测。信道感测机制是一种跨层方案，其中CCA在PHY层（在发送器和接收器侧使用）运行，影响MAC层，包括节点的能耗和整体吞吐量。本文评估了各种流量条件下基于IEEE 802.15.4标准的MAC协议。它提出了一种自适应CCA（A-CCA）定时机制，通过减少虚假唤醒和空闲侦听模式下的节点时间来提高节点能耗。ACCA帮助发射器在噪声水平以上的高流量和干扰环境中调整其无线电功率，从而使接收器能够监视发送器信号并相应地调整其唤醒周期。使用Cooja模拟器以及基于CC2420的平台对提出的方案进行了评估，以报告改进的节点寿命并减少严重干扰下的虚假唤醒。拟议的方案报告了轻载和重载环境中无线电占空比的降低（分别为1.10％和1.18％）。研究结果表明，ACCA降低了网络功耗，总体上降低了6％的功耗以延长节点寿命。