## 4 Results and Discussion  
Castalia 3.3 [57] and OMNET++ 4.6 [59] simulators were used to evaluate the performances of EQPD-MAC and comparative works. The simulation adopts parameters from TelosB [60] and MicaZ [61] sensor node and CC2420 radio, which is a commonly used low-power RF transceiver in WSN hardware notes. Receiving and idle operation both incur 62 mW of power, whereas transmitting and sleeping operation use 46.4 mW and 1.4 mW of power, respectively. To provide reliable wireless connectivity, the radio chipset uses the 2.4 GHz frequency spectrum to transmit data at 250 kbps over a distance of around 50 m.  
The sink is located at the center of the sensor field of 200 m \(\times\) 200 m square region, with 45 nodes scattered around randomly. Packets with length of 28 bytes are generated by each sensor node. In Castalia, the data are completely random. Each packet is assigned a random value (_R_) between 0 and 1, which represent its priority. Each time, a random number between 0 and 1 is generated and it is used to differentiate between priority packets, as shown in Table 4. Each priority has a 25% probability of occurring in the simulation, which means that all priorities will have equal possibilities. In order to acquire a clear understanding of the network's performance and to ensure that all nodes get the same amount of all priority packets, such circumstances were used to conduct the simulation. However, we have also tested the proposed protocol with P\({}_{4}\) having 5%, P\({}_{3}\) having 15%, P\({}_{2}\) having 30% and P\({}_{1}\) having 50% probabilities, which may represent a different application. The outcomes are almost identical.  
TelosB and MicaZ uses TinyOS as their platform. TinyOS has a default data field size of 28 bytes. In WSNs, there are packets of varying sizes and types, and the priority of these packets differ from one another. Smaller packets are preferred to larger ones because the retransmission of a long packet that is lost will be much more energy extensive. Packet header, data, and trailer are the three primary elements of most network packet formats. In order to transmit packets, the physical layer uses the packet header and trailer (MAC layer information). To ensure a reliable transmission, the MAC layer might split a large data file into smaller ones before sending it. Small packets, on the other hand, can be transmitted quickly and reliably. As a result, a reduction in total energy consumption is achievable.  
Before the sensor node transmits Tx-beacon, it creates a random value, and if the produced value is less than \(p\), it transmits. The AODV routing protocol is used to route data packets from sensor nodes to a sink node in this network, through multiple hops. Table 5 contains the simulation parameters. The simulation runs for 10,000 s which ensures that at least 10,000 packets are simulated. The simulator was used to assess the proposed protocol's performance and comparison with three other widely used MAC protocols. All the protocols use _p_-persistent CSMA to transmit Tx-beacons and data packets.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Priority** & \(R\) & \(p\) **(Linear)** \\ \hline P\({}_{1}\) & 0.75 \(<\) \(R\) \(\leq\) 1 & 0.1 \\ \hline P\({}_{2}\) & 0.5 \(<\) \(R\) \(\leq\) 0.75 & 0.2 \\ \hline P\({}_{3}\) & 0.25 \(<\) \(R\) \(\leq\) 0.5 & 0.3 \\ \hline P\({}_{4}\) & 0 \(<\) \(R\) \(\leq\) 0.25 & 0.4 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Assignment of Priority Packets.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Area & 200 m \(\times\) 200 m \\ \hline Sensor Nodes & 45 \\ \hline Radio & CC2420 \\ \hline Simulation Time & 10000 s \\ \hline Frame Time & 125 ms \\ \hline Activation Time (TA) & 12 ms \\ \hline CCA & 0.128 ms \\ \hline Waiting Timeout (\(T_{w}\)) & 5 ms \\ \hline Data Rate & 250 kbps \\ \hline \hline \end{tabular}
\end{table}
Table 5: Simulation Parameters.