Beacon Time Analysis

Open NetSim, Select Examples->IOT-WSN->Wireless Sensor Networks->Beacon Time Analysis then click on the tile in the middle panel to load the example as shown in Figure 4‑35.

Figure 4‑35: List of scenarios for the example of Beacon Time Analysis

The following network diagram illustrates, what the NetSim UI displays when you open the example configuration file.

Figure 4‑36: Network set up for studying the Beacon Time Analysis

Settings done in sample config file

  1. The following Environment properties are already set, as Manually Via Click and Drop.

  2. In SinkNode->INTERFACE_1(Zigbee)> Datalink Layer enable Beacon mode set Superframe Order (SO) -> 10 and Beacon Order (BO) -> 12

    C:\Users\TETCOS_PC\Desktop\Capture.PNG

Figure 4‑37: Datalink layer Properties window for Sink node

  1. In Adhoc Link Properties change Channel characteristics-> Path Loss only, Path Loss Model -> Log Distance and path loss exponent ->2.

  2. Generate SENSOR_APP Traffic Between Wireless_Sensor_1 to WSN_Sink_3 and set the transport layer protocol as UDP and other properties are default.

  3. Enable Packet Trace and Plots.

  4. Set Simulation time as 200 sec.

Theoretical Beacon Time Calculation

  • Beacon Interval (BI)= Super Frame duration (Active Period) + > Inactive Period (IP).

  • BI = abasesuperframe duration*2 ^BO = 15.36ms * 2^12 = 62914.56ms > \~ 62s.

  • SD = abasesuperframe duration*2 ^SO = 15.36ms * 2^10 = 15728.64ms.

  • To find Inactive period, IP = BI – SD = 62914.56ms - 15728.64ms = > 47185.92ms.

  • Super Frame duration is divided into 16 slots (1st slot > is allocated for beacon frame).

  • Each slot time = 15728.64ms / 16 = 983.04ms

NetSim Results:

  • Open packet trace and filter CONTROL_PACKET_TYPE to > Zigbee_BEACON_FRAME, users should get four zigbee_beacon_frames at > 0, 62.9, 125.8, 188.7 secs (approx.) for each Sensor_Node, because > the time interval between two beacons frames is 62 seconds. Since > we have 2 nodes so user can get 4 beacon frames for each node.

  • 4 beacons were transmitted, so beacon time = 983.04ms * 4 = > 3932.16millisec (since 1 beacon = 1 time slot). Check the beacon > time in IEEE 802.15.4 metrics window.