# An Energy-Efficient Coverage Algorithm for Macrocell--Small Cell Network Systems
## 4 Proposed Algorithm  
We employ the MBS's centralized-control-based management method to manage the resource allocation of BSs along the mobile paths of users. Moreover, we use SBSs to provide connection services to users in due course, in order to reduce energy consumption. The algorithm is executed at fixed time intervals, and the period of each time interval is denoted by \(t\). The \(t\) value is sufficiently small (hence, paths within any period can be assumed to be direct paths), an assumption which is made based on the moving speed of users. Meanwhile, as described in Section 3.1, we assume the presence of a powerful deep learning system (one that has been subjected to countless rounds of learning and testing) within the data center, and that it can predict the direction of a user's path with virtually no errors, particularly when the period is short (since the likelihood of changes occurring to a user is lower). During any given period, the connection in users' direct paths is divided into three areas, as shown in Figure 3 and Definition 1, and operations are conducted for each area in order to allow the BSs to better solve the issue of coverage insufficiency, ensuring unhindered network use through the BSs. However, signal coverage does not guarantee effective connection in cases in which channels are insufficient. **Definition 1. **_Starting point, end point, relay process_  
The user's position when the algorithm is executed is referred to as the user's starting point. The user's position, predicted at time \(t\) from the starting point, is referred to as the user's end point. Excluding the starting and end points, the direct path from the starting point to the end point is referred to as the relay process. **Definition 2. **_Path process_  
The user's path during the period (i.e., starting point \(\rightarrow\) relay process \(\rightarrow\) end point) is referred to as the path process. **Definition 3. **_Support overlay_  
If there is no coverage gap between any two adjacent SBSs in the relay or path process, then when the SBSs in the relay or path process are activated, users may be under the coverage of the signals of these SBSs; this situation is referred to as support overlay. **Definition 4. **_A, B, and C_  
A is defined as the SBS status (i.e., the presence or absence of an SBS, and, if present, whether the SBS's power can be amplified to facilitate coverage) in the starting point area. B is defined as the SBSs status (i.e., the presence or absence of SBSs, and, if present, whether the SBSs are providing support overlay) in the relay process area. C is defined as the SBS status in the end point area. These statuses of the user's path process (i.e., starting point \(\rightarrow\) relay process \(\rightarrow\) end point) are denoted as ABC. A flow chart illustrating the proposed coverage algorithm is shown in Figure 4. We begin by sorting all users in order of priority (they will be processed in order of priority). Next, we will determine if the end point of user \(i\) will fall within a coverage hole. If it does not fall within a hole, the processing procedure for Case 1 (which will be covered in detail later) will be used; if it does fall within a hole, we will identify the type of BS that is providing service to user \(i\) at the starting point. If user \(i\) is being serviced by an SBS at the starting point, the processing procedure for Case 2 (which will be covered in detail later) will be used. If user \(i\) is being serviced by the MBS at the starting point, the processing procedure for Case 3 (which will be covered in detail later) will be used. Regardless of whether the processing procedure for Case 1, 2, or 3 was used, we will record the relevant data  
Figure 3: Three areas of connection in direct paths during the period. after the processing process has been completed. When processing has been completed for user \(i\), we will verify if all users have been processed. If there are users who have not been processed, we will perform the above operation on the next batch of users.