# A Cross-Layer Media Access Control Protocol for WBANs
## 6 Conclusions  
As an emerging network capable of collecting human-centered information, WBAN technology plays an important role in the deep integration of computer technology with fields such as healthcare, sports, and education. In this paper, we propose a cross-layer base MAC protocol for WBANs. The protocol considers the reliability requirements for heterogeneous data transmission and makes targeted adjustments to the superframe structure and data retransmission mechanism. Additionally, a power adjustment mechanism is proposed, taking into account the channel conditions and the reliability requirements of data transmission, effectively improving the network lifetime. Furthermore, a concise node cooperative transmission mechanism is proposed to further enhance the network lifetime. The protocol mechanism can effectively guarantee the quality of service for differentiated data and improve network lifetime and energy efficiency. It helps improve the user experience quality when using WBAN for health monitoring services, avoiding frequent battery resets of nodes in the network and making it easier for users to accept WBAN health monitoring services.  
Compared to existing protocols, our proposed protocol considers the reliability requirements of data transmission when performing power adjustment. Based on the adaptability to channel conditions, nodes adjust the transmission power according to the real-time data type and importance, effectively improving the network lifetime while ensuring network service quality. Additionally, the cooperative transmission mechanism between nodes further improves network lifetime by addressing the issue of uneven energy distribution caused by differential transmission power.  
The protocol design considers the common data transmission requirements of e-health applications. For nodes that generate data without clear periodicity and where the importance of data cannot be clearly measured, it is challenging to efficiently adjust the data transmission power of nodes. Additionally, when transmitting data at lower power levels, the inability to assess data importance may affect the accuracy and reliability of e-health applications if the data are not retransmitted. In future work, we will further optimize the protocol mechanism and study mechanisms that can simultaneously improve data transmission efficiency and extend the lifetime of such nodes. Based on this, we will investigate methods for cooperative transmission among nodes in multiple WBAN coexistence scenarios, exploring the efficiency and feasibility of multi-network cooperation.  
Conceptualization, [PERSON] and [PERSON]; methodology, [PERSON]; software, [PERSON] and Y.J.; validation, [PERSON] and L.Z.; formal analysis, [PERSON]; investigation, [PERSON] and L.Z.; data curation, [PERSON]; writing--original draft preparation, Y.J. All authors have read and agreed to the published version of the manuscript.  
This work was supported in part by the National Natural Science Foundation of China under Grants No. 61701190, Jilin Provincial Social Science Foundation under Grants No. 2022C108 and Project of Jilin Province Development and Reform Commission Grant No. 2019 FGWTZC001.  
Not applicable.  
The authors declare no conflicts of interest.