# BNS: A Framework for Wireless Body Area Network Realistic Simulations
## 4 Use Cases
### Remote Monitoring Using X73-Phd  
A possible use case considered in this paper is a remote monitoring WBAN scenario, in which a patient's vital signs are monitored using blood pressure monitor, thermometer, glucose meter, pulse oximeter and basic ECG. The network topology is formed by a coordinator node located in the waist and five PHD agents located in the body as shown in Figure 8. To model the channel behavior and consider body mobility, the loss map and the temporal variation model proposed in [23] are used. We used Direct Route Routing (DRR) recommended in the IEEE 802.15.6 standard. The PHY and MAC layers configurations used were those described in the WBAN standard and the MAC layer version used is the one provided in the BNS framework.  
In this use case, we simulated three agent-initiated scenarios considering operating modes available in the application layer proposal. The three agent-initiated scenarios are: Unconfirmed Mode, Confirmed Mode, and a Retransmission Mode proposed in [1]. The node coordinator (hub) uses the _Manager_ application. The blood pressure monitor transmits one measurement every 15 min. The oximeter sends a reading every 15 s. The glucose meter transmits one measurement every 5 min. The thermometer sends the temperature every 3 min. The ECG sensor considered is a device that receives signals of electrodes deployed in the body, and transmits these signals to the manager; so, it transmits 80 millivolt samples per 0.8 s. The total simulation time was 12 h.  
The results available in the application are the total control packets exchanged per node, the measurement packets received by the manager per node, the measurement packets sent by each node, and the total associations made per agent [1]. In this use case, we analyzed the total successful vital sign measurements delivered to the manager. Figure 9 depicts the results for these scenarios. As it can be seen in the figure, the proposed retransmission mode increases the number of packets delivered to all agents, delivering almost 100% of all messages. Additionally, it avoids the waiting time for a new association  
Figure 8: Network topology used in remote monitoring scenario.  
handshake, and by retransmitting the messages. For the oximeter, using the unconfirmed mode, almost all packets were delivered, even without guaranteeing reliability. However, the confirmed mode improves reliability, but it needs reassociations frequently. Results show that with the retransmission mode, the PDR in the WBAN network increases, offering better network performance for remote monitoring applications.  
An important network parameter to be considered when analyzing the performance of a WBAN is latency. Figure 10 depicts the number of packets with a given latency, for all measurements transmitted by agents in the simulations. The latency is calculated from the moment of packet creation, at the application layer of the agent, until the moment it is received at the application layer of the manager. The figure shows that most packets have an average latency of 180 ms in the retransmission mode and confirmed mode and 30 ms in no confirmed mode. Results show that the latency is maintained at acceptable values for remote monitoring applications.  
This simulation scenario allows us to evaluate the performance regarding PDR and latency, using different modes of operation in the application layer, taking into consideration the effect of the wireless channel and the mobility of the human body. This comparative study is possible due to the resources made available in the proposed WBAN framework.