Читать книгу Intelligent Security Management and Control in the IoT - Mohamed-Aymen Chalouf - Страница 30

The multicriteria decision-making module that we suggest should be useful in different IoT contexts, particularly in M-RAN and CRN contexts. To illustrate the use of the retained approach in these two contexts and evaluate performances in each of them, we consider, in this section, two significant IoT use-cases: VANET and CR-VANET (Cognitive Radio VANET). In a VANET network, the On-Board Unit (OBU) is installed in the vehicle and includes a wireless transmitter receiver and various sensors, whereas a Road-Side Unit (RSU) is deployed in strategic locations along the route to facilitate communication between the vehicle and the infrastructure (V2I: Vehicle to Infrastructure). In V2I, information is exchanged between the vehicle and the RSU, or potentially a cellular network. VANET applications can be divided into three main categories (Javed et al. 2014): road safety (collision detection, cooperative driving, etc.), traffic management (route guidance, traffic light synchronization, etc.) and user infotainment (Web, streaming audio/video, etc.). Safety applications do not tolerate a transmission delay higher than 0.5 s (Javed et al. 2014), whereas traffic management applications are less demanding, with a tolerated latency between 0.1 and 1 s (Javed et al. 2014). As for infotainment applications, they generally accept greater latency, in order of 1–5 s. Nevertheless, some applications of this type, like multiplayer games, may require lower latencies of 0.1–1 s (Javed et al. 2014).

Based on the access networks detected or the channel available, and depending on the QoS requirements of the VANET applications, the suggested multicriteria decision-making module will select the best access network or radio channel available for a specific case. To do this, the utility function will calculate the scores of different candidate networks/radio channels to select the one that has the highest score.

Since we are considering combustion rather than electrical vehicles, we suppose that there is no energy constraint. Thus, the scores calculated from the different candidate channels are based only on the QoS parameters.

To evaluate the approach retained, we consider two representative types of transmission: multimedia emergency notification and infotainment applications, especially restaurant reservation. Table 1.1 summarizes the QoS requirements of these services.

Table 1.1. Some vehicular network services and the corresponding QoS parameters

Type of service	Relevance of QoS parameters
Multimedia emergency notification	Latency (+++), bandwidth (+++) and packet loss (+)
Restaurant reservation	Latency (+), bandwidth (+) and packet loss (+)

Table 1.2 shows the estimation of the weight of the data flow, the delay and the packet loss rate for services considered in the vehicle networks. These weightings are based on the importance of each parameter in Table 1.2.

Table 1.2. Weight estimation for services considered in vehicular networks

Type of service	Weight estimation
Delay	BP	PLR
Multimedia emergency notification	0.43	0.43	0.14
Restaurant reservation	0.33	0.33	0.33