ASR: Average secrecy rate of UAV-assisted MEC networks with random eavesdroppers

The rapid development of unmanned aerial vehicle (UAV) technology and mobile edge computing (MEC) has created new opportunities for efficient data processing and transmission. UAV-assisted MEC enables data transmission from UAVs to a base station (BS) equipped with MEC capabilities. However, ensuring the security of these transmissions is a concern, especially when UAVs operate in open airspace. In this paper, we introduce a coordinated multi-point (CoMP) offloading model aimed at enhancing the secure transmission performance of the network. The airspace is divided into several equal-sized hexagonal cells, with multiple UAVs collaborating to offload data to a BS with MEC. During this process, the locations of potential eavesdroppers are randomized as they attempt to intercept the data transmitted by the UAVs. Based on this model, we first derive the success communication probability (SCP) for a typical BS and an eavesdropper using stochastic geometry. We then introduce the concept of secure transmission rate, precisely the average secrecy rate (ASR). Further, we characterize the ASR in the presence of random eavesdroppers. Finally, we analyze the effects of various parameters on transmission performance. The results of our simulations closely align with our numerical findings, confirming the accuracy of our analysis. Notably, the ASR of the proposed system is nearly four times higher than that of an offloading model without cooperation. Moreover, compared to a user-centric offloading model with CoMP, the ASR increases by 5.37 %, enhancing system performance and reducing search overheads.