## 4 The Scheduler Architecture
### Queue Management System
#### 4.1.1 Reference Scheduling Technique  
The primary reason behind the DSC technique [32] is to maximize profit as it evaluates the decision on admission on the basis of comparing the potential profits relating to the acceptance or declining of a task. There is a difference between this technique and other previously existing and related algorithms [35; 36; 37], in which it processes a situation without commitment, and the job values are subtracted from the penalties. The DSC scheduling technique upholds a tentative schedule most of the time. During the processing of a task request, the DSC scheduler ascertains if there is a possibility of appending a new task at the end of the ongoing tentative schedule while trying to meet its deadline. The task is, however, admitted and appended should the deadline be met; if not, the scheduler calculates if it is reasonable in admitting the task based on the profit of either to accept and decline the task. Should the profit that is related with acceptance not be sufficient enough, then the task is, however, rejected. If it is sufficiently large, then the task is scheduled to another time interval. The DSC algorithm is defined as seen in the pseudocode in Algorithm 1 below. Let the \(T_{a}\) be the tasks to be released and the threshold as \((1+\alpha)\). As in line 4, \(T_{a}\) gets added and appended to the current schedule if appendable. Otherwise, the \(Profit_{accept}\) and \(Profit_{decline}\) related to admitting or declining \(T_{a}\) are compared. In line 6, if a better profit is yielded in admitting \(T_{a}\), then \(T_{a}\) is admitted at the end by \(d_{a}\), and the current schedule after \(d_{a}-p_{a}\) is moved and adjusted accordingly. Otherwise, if admitting \(T_{a}\) does not yield a better profit, \(T_{a}\) is a declined service. The threshold \(1+\alpha\) will be optimized after deriving the competitive ratio as a function of \(\alpha\). Figure 4: The scheduling architectural in 5G NR system. ```
1:loop
2:upon event : Task \(T_{a}\) is released
3:if \(T_{a}\) is appendable then
4: Append \(T_{a}\) to the end of the tentative schedule
5:else
6:if \(Profit_{accept}>(1+\alpha)Profit_{decline}\)then
7: append \(T_{a}\) at the end by \(d_{a}\)
8: move and modify the schedule after \(d_{a}-p_{a}\) accordingly
9:else
10: drop \(T_{a}\)
11:endif
12:endif
13:endloop
```  
**Algorithm 1** DSC Scheduling Algorithm  
EDF scheduling is a popular policy and has consistently been employed for most scheduling policies, showing itself to be quite optimal under different matrices [20; 22; 25]. When executing any task in EDF, the task can be pre-empted if any other periodic instance with an earlier deadline is ready for execution and becomes active. EDF is also priority driven and dynamic. Hence, priorities are calculated and changed while the processes are running. Another scheduling mechanism that can be utilized as a standard for comparison purposes is the \({}^{CH}\!/_{\theta}\) scheduling mechanism in [38]. This technique assumes there are \(J\) queues in the system in which a selection must be made from the queue to be served. It is also assumed that there are \(J\) groups or levels of rewards each against a queue. Two essential steps make up the \({}^{CH}\!/_{\theta}\) scheduling technique, which are  
* Inserting the new task to \(j\) according to its rewards in the first come first serve order upon arrival. * When the server is not in use, the mechanism chooses the queue to be served according to \({}^{CH}\!/_{\theta_{k}}\) and processes the task that is in front of the queue. In the case of EDF scheduling, is it assumed that there is no prior information about the servicing times, while \({}^{CH}\!/_{\theta}\) scheduling assumes that the deadline is statistically known based on the probability of abandonment. This, however, is very key in terms of the case of non-deterministic service time. Therefore, there is a possibility case that shows the advantage of employing the knowledge of servicing time upon arrival in the EDF case presented.