## 5 TSCH Link Scheduling Visualization and Data Processing  
Research in the field of network protocol requires simulators as a tool for visualization, validation, and performance testing, and one of the research topics in this field is scheduling algorithms. Studies of scheduling algorithms commonly use NS-2, NS-3, OPNET, and other simulators. However, the centralized scheduling algorithm on TSCH has very few supporting simulators, including NS-3 [29] and 6 TiSCH simulator [30], which only provide limited support. Therefore, this research seeks to develop a tool for developing a centralized link-scheduling algorithm on the IEEE802.15.4e TSCH network. We succeeded in making a tool known as the TSCH link-scheduling visualization and data processing or abbreviated as TLS-VaD. The TLS-VaD was developed to meet the following objectives:  
* It visualizes the transmit and receive processes between nodes in a network in a number of cycles. The data in the nodes of each cycle will move toward the master node gradually. Information on which nodes are active in each round is determined by the schedule matrices generated by the scheduling algorithm. With this visualization, researchers can determine whether the developed scheduling algorithm is in accordance with the plan or not. * It provides data output that shows the performance of the developed scheduling algorithm: number of active timeslots per slotframe (\(\lambda\)), number of cycles (C) and duty cycles (DC), and number of required channel offsets (ChOffs). The output of this tool will show the following performance:
* Number of active timeslots per slotframe (\(\lambda\)): the fewer active timeslots, the shorter the on time of network nodes, thereby saving on the amount of energy used. * Number of cycles: indicates the speed of the scheduling algorithm in generating schedules. The smaller the number of cycles, the faster the algorithm can create a schedule. In terms of centralized network management, the faster the schedule, the better, because the resources to create the schedule can be used to serve other networks. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Scheduling Algorithm** & **Active Timeslots (\(\lambda\))** & **Cycles (C)** &
\begin{tabular}{c} **Total Channel Offsets** \\ **(ChOff)** \\ \end{tabular} \\ \hline IRByTSA & 17 & 8 & 23 \\ FTSA & 18 & 7 & 24 \\ FLSA & 17 & 5 & 17 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Temporary recapitulation of the scheduling algorithm performance. Duty cycle: number of active timeslots when connected to the size of the slotframe. At the same slotframe size, the smaller the duty cycle, the better, because it indicates a network condition that is increasingly energy-efficient. Required channel offset: used to get the channel offset per cycle (ChOff/C) parameter. ChOff/C shows the average number of channel offsets used in each cycle. Since the 802.15.4e standard only provides 16 channel offsets, the ChOff/C value should be smaller than 16. The smaller the ChOff/C value, the better, because it will reduce the possibility of interference with other nodes that are active at the same time/cycle. Even though this research assumes there is no interference, it is still important to note ChOff/C data as preliminary information for researchers who want to include interference problems as a parameter to consider. * It provides a platform for researchers in the field of centralized link-scheduling algorithms to test the performance level of developed algorithms. A scheduling algorithm has good performance if all output data released from TLS-VaD has a minimum value. If we want to improve the performance of the algorithm, it can be repaired separately, because in order to use TLS-VaD, researchers can simply create an executable (exe) file from the developed algorithm and embed the file on TLS-VaD.