## 3 Results and Discussion
### MAC and Physical Layers  
The IEEE 802.11 standard defines the methods to initiate, maintain, and close the bidirectional links between mesh STAs and also establishes by default the Hybrid Wireless Mesh Protocol and the airtime link metric. Tables 5 and 6 present the parameters configured in the simulator for the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Traffic Type**} & \multirow{2}{*}{**Applications**} & \multicolumn{3}{c}{**Packet Size**} & \multicolumn{3}{c}{**Packet Interval**} \\ \cline{3-6}  & & **Length (Bytes)** & **Distribution** & \multicolumn{2}{c}{**Interarrival Time (s)**} & \multirow{2}{*}{**Distribution**} & \multirow{2}{*}{**EDCA**} \\ \cline{3-6} \cline{6-6} \multirow{-2}{*}{\(1\)} & Demand Response, & & **NL1** & **NL2** & & \\  & Outage Management. & 60 & Exponential & 0.075 & 0.025 & Exponential & Voice \\ \hline \multirow{4}{*}{2} & Video surveillance, & & & & & (Highest Priority: 1) \\  & Overhead Transmission & & & & & \\  & Line Monitoring, & 60 & Exponential & 0.075 & 0.025 & Exponential & Video \\  & Substation Automation & & & & & (Priority 2) \\  & Systems (SAS). & & & & & \\ \hline \multirow{4}{*}{3} & Home Energy & & & & & \\  & Management (HEM), & 512 & Deterministic & 0.075 & 0.025 & Deterministic & Background \\  & Electric Vehicles (EVs) & & & & & (Priority 3) \\ \cline{1-1}  & Charging & & & & & \\ \hline \multirow{4}{*}{4} & Meter Data & & & & & \\  & Management & 512 & Deterministic & 0.075 & 0.025 & Deterministic & Best Effort \\ \cline{1-1}  & & & & & (Lowest Priority: 4) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Applications classification, distributions, and parameters. NL, Network Load. \begin{table}
\begin{tabular}{c l l} \hline \hline
**Variable** & **Description** & **Value** \\ \hline
**simulator** & Simulator & ns-3.28 \\
**numNodes** & Number of nodes & from 9 to 36 \\
**distanceNodes** & distance between nodes & 80 m \\
**numRuns** & Number of runs & 21 \\
**simTime** & Simulation time & 50 s \\
**transportLayer** & Transport layer & User Datagram Protocol (UDP) \\
**randomGenerator** & Random number generator & MRG32K3a \\ \hline \hline \end{tabular}
\end{table} 
Table 3: General simulation parameters. MPM and HWMP protocols, where, among others, the following variables are defined: maximum thresholds to consider invalid links, maximum number of neighbors (peer links) allowed, the reactive mode of HWMP, lifetime of the reactive routing information, and the conditions to indicate a route as unreachable. As mentioned in the previous section, nodes must be allowed to establish links only with the neighbors at their sides. To reinforce this, the maximum number of peer links per node was set to four. On the other hand, the 802.11s model implemented in the ns-3 simulator considers a link as not valid if the consecutive number of lost beacons achieves a configurable threshold (\(maxBeaconLoss\) in Table 5). A value of 20 lost beacons was selected for this parameter. In addition, when a station is unable to transmit to its peer a number of successive data frames, the ns-3 implementation by default closes their peer link. This parameter and the other variables presented in Tables 5 and 6 were configured with their default values. These selections do not affect the performance evaluation carried out, since the values are the same for both compared protocols. Table 7 presents the configured values for the physical layer, detailing among others the following parameters: 802.11a as the selected physical layer, frequency channels for control and data traffic, and the propagation model. Except for the number of control and data channels and their frequencies (which have been defined in this proposal), well-known values were chosen for the rest of the parameters in Table 7, which were used in most smart grid NAN simulations. As previously said, this selection does not affect the comparison between the protocols.