# Agreement Technologies for Coordination in Smart Cities
## 3 Applications
### Distributed Coordination of Emergency Medical Service for Angioplasty Patients
#### 3.4.2 Simulation Experiments
To achieve an efficient dynamic reassignment of ambulances, the execution of the EMS coordination algorithm is furthermore performed with every new significant event (i.e., any time there is a significant change in the system due to new patients) or with a significant change in travel time or state of any of the EMS participants. In the experiments, we tested the performance of the proposed EMS coordination method with respect to the FCFS benchmark approach. The comparison is based on the relative performance function \(P=(t_{\text{FCFS}}-t_{\text{OR}})/t_{\text{FCFS}}\times 100\) (%), where \(t_{\text{FCFS}}\) and \(t_{\text{OR}}\) are average patient delay times of the benchmark FCFS approach and the proposed model, respectively. The simulation results of performance function \(P\) for the two simulated cases of patient frequency appearance of 1 and 5 new patients every 10 time periods are presented in the following. The performance of the proposed approach increases as the number of angioplasty-enabled hospitals increases from almost identical average patient delay in the configuration setup with 2 hospitals up to 87.14% with 50 hospitals, as can be seen in Figure 12. Observing the performance dynamics with respect to the varying number of hospitals, it is evident that the performance of the proposed EMS coordination method increases, on average, proportionally to the increase of the number of hospitals. With a relatively low number of angioplasty-enabled hospitals (less than 15), our proposed EMS coordination approach performs, on average, better than FCFS by up to 15%. As the number of hospitals increases, the performance improves, on average, up to a maximum of 39.98% for the first case (Figure 13) and up to 87.14%, for the second case (Figure 12). However, mean patient delay improvement for the two cases is 35% and 45.5%, respectively. Figure 12: Average patient delay time of the proposed EMS coordination approach vs. the FCFS strategy (%) for the frequency of appearance of 1 patient each 2 time periods. The static assignment of the FCFS principle discriminates against patients appearing later. Since ambulances are not equally distributed in the area, the proposed EMS coordination method compensates for the lack of EMS resources and their unequal distribution by reassigning them dynamically to pending patients. Dynamically optimised reassignment of EMS resources in real time is the main key to the improvement of the system's performance. Thus, proportional to the increase of the number of hospitals, there is a constant improvement of performance. Even though the velocity of the EMS actors is not a relevant factor in the comparison of the performance of our proposed EMS coordination solution nor of the FCFS method, looking individually at the performance of each one of these methods, it is evident that the assignment cost accumulated through the time will be lower when the velocity of the EMS actors is higher. Our simulation results show the efficiency of the proposed solution approach, resulting in significantly lower delay times for angioplasty, on average. Of course, the effectiveness of the proposed model depends on the initial classification of patients, and the related determination of the urgency of their cases, as well as on the timely availability of cardiology teams and hospitals. Still, as the current experience shows, good quality patient assessments and the EMS resource availabilities can be assured in practice. To implement our approach in practice, a patient's location needs to be known to the system. Ideally, patients should contact the ECC through a mobile phone with GPS for easier location. In addition, ambulances should have a GPS and a navigator for localising the patient and navigating the way to him/her, as well as a means of communication with the rest of the EMS participants, and a digitalised map showing ambulances, patients, and hospitals. Moreover, hospitals should have a digitalised receptionist service to receive and process relevant data of a patient before his/her arrival.