# Evaluating the Impact of Pre-Configured Uplink Resources in Narrowband IoT
## 4 Experiments  
In evaluating PUR's functionality, we conducted a series of experiments focusing on different parameters. Table 1 outlines the parameters affecting the behavior of the UE at various CE levels, while Table 2 lists the parameters relevant to our simulation setup. The UEs were divided equally among three coverage conditions: outdoors, indoors, and \"deep indoor\" environments, such as basements.  
In the default RAP, a UE sends one message per day and enters an IDLE state after a 20 s wait in connected mode. For EDT and PURs, a UE moves into the IDLE state immediately after sending an uplink packet and receiving the corresponding acknowledgment. The radio signal is weaker for \"indoor\" and \"deep indoor\" placements, requiring more repetitions for the same message, as shown in Table 1, columns CE1 and CE2. The path loss of the UE is calculated using the Winner+ channel model, which simulates both line-of-sight (LOS) and non-LOS propagation conditions. Additionally, the configurations include building losses of 15.4 dB for \"indoor\" and 20.9 dB for \"deep indoor\", as derived from [29].  
Our simulations lasted 45 min, but we concentrated our evaluation on a central 15 min interval. The initial 15 min period usually produces little results because UE are scheduled in an empty cell, resulting in excellent transmission conditions. However, after this period, the ongoing transmissions from the earlier UE create a more realistic environment and yield significant results. To account for transmissions initiated but not completed within this time frame, we simulated an additional 15 min, introducing new transmissions to maintain channel activity and allowing earlier UE to complete their transmissions. However, this does not apply to PURs since eNB allocates resources beforehand, reducing the dependence on interference from other UE.  
Initially, we validated the LENA-NB simulator extended with PURs against the original LENA-NB simulator [11]. The results from this validation are depicted in Figure 9. We conducted a comprehensive comparison, which included generating results for 50,000 UEs to evaluate energy consumption. The results indicate that the energy consumption levels of EDT and the default RAP in our experiment were very similar to those found in [11]. After validating our simulation setup, our research primarily delves into PUR--an area  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Parameter** & **CE0** & **CE1** & **CE2** \\ \hline rsp-Thresholds & – & \(-116\,\mathrm{dBm}\) & \(-128\,\mathrm{dBm}\) \\ nprach-StartTime-r13 & \(256\,\mathrm{ms}\) & \(256\,\mathrm{ms}\) & \(256\,\mathrm{ms}\) \\ nprach-SubcarrierOffset-r13 & 36 & 24 & 12 \\ nprach-NumSubcarriers-r13 & 12 & 12 & 12 \\ nprach-SubcarrierMSG3-RangeStart-r13 & twoThird & twoThird & twoThird \\ maxNumPreamble-AttemptCE-r13 & 10 & 10 & 10 \\ numRepetitionsPer-PreambleAttempt-r13 & 1 & 8 & 32 \\ npdech-NumRepetitions-RA-r13 & 8 & 64 & 512 \\ npdech-Offset-RA-r13 & zero & zero & zero \\ \hline \hline \end{tabular}
\end{table}
Table 1: The configuration of the LENA-NB simulator.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Parameters** & **Settings** \\ \hline Area & 4.91 square kilometers \\ UE deployments & Outdoor, indoor, deep indoor \\ Attenuation model & Winner plus propagation (10\%) \\ Packet size & 49 bytes \\ Base station height & 50 m \\ eNB and UE antenna & Isotropic Antenna Model \\ NB-IoT battery capacity & 5 Watt-hours/18,000 Watt-seconds \\ Simulation time & 45 min \\ \hline \hline \end{tabular}
\end{table}
Table 2: The LENA-NB experiment setup.  
that we consider crucial for understanding energy efficiency in the NB-IoT. Therefore, in the following sections, we will delve deeper into the analysis of PUR, emphasizing its significance and potential impacts on network performance.