## 3 Proposed Optimization Model
\[D_{t}=dist(\alpha,\ \beta), \tag{2}\]  
Figure 1: Block diagram of the proposed model. Using the computed value of \(n_{s}\), the source node updates its forwarding table and sends the data toward the mobile edge based on the hop-to-hop paradigm. However, it might be a case where the mobile edge is directly accessible by the source node. In such a situation, the source node sends the data directly without evaluation \(n_{s}\) values. In the proposed model, the network edges are mobile and adjust the coordinates frequently; thus, its latest position \(e_{ps}\) can be determined using Equation (3). \[e_{ps}=(P_{0}-P_{i})/S \tag{3}\]  
In Equation (3), \(P_{i}\) and \(P_{0}\) are initial and current 2D coordinates, whereas \(S\) is the speed of the mobile edges. The positioning coordinates are obtained using the installed global positioning system (GPS) on mobile edges. Later, the network edges on different levels initiate their work collaboratively, to deliver the MIoT data toward the SDN controller using employed switches and routers. In the proposed model, SDN deploys on the top level and it supervises all of the network operations in a centralized manner. To support the data protection on each level, SDN generates a secret key \(S\), which is to be divided between the set of \(n\) network edges based on [PERSON]'s secret sharing scheme [37]. It is also called \((t,n)\) threshold based secret sharing, such that, any \(t\) subset of network edges are sufficient to recreate the secret key \(S\). However, less than \(t\) or a fewer number of subkeys cannot reconstruct the secret key \(S\). Afterwards, the SDN controller transmits the share of the key \(S_{i}\) to the network edges, which is also digitally signed by the SDN master key \(mk_{ SDN}\). On receiving the secret share, each network edge node is first verified by decrypting the secret share, and afterward, it further floods towards an individual node that is associated with the network edge. Let us consider that \(m_{i}\) denotes message pieces that must be sent from the nodes toward the network edges. Then, nodes perform a mapping function using a set of subkeys \((S_{0},\ S_{1},\ldots,S_{t-1})\), and are digitally signed by their master keys \(mk_{n}\), as given in Equation (4). \[E_{i}=mk_{n}((S_{i},\ m_{i}),xor) \tag{4}\]  
After receiving the encrypted data \(E_{i}\), the network edges verify it, and upon successful verification, the data are transmitted toward the controller using deployed switches, as given in Equation (5). \[X_{i}=f(IV+(m_{i},\ S_{i})\ xor)+D \tag{5}\]  
where \(IV\) is a nonce, and is used to make the encryption process more randomized, and \(D\) denotes the digital signature of the network edge. When the SDN controller receives the encrypted data \(X_{i}\), it performs a decryption function \(Y_{i}\), as given in Equation (6), and forwards to the application devices for connected nodes that can retrieve it for the needed purpose. \[Y_{i}=((m_{i},X_{i})\ xor) \tag{6}\]  
Figure 2 illustrates the flow chart of the proposed model. It initiates a network-sensing component using IoT devices and multimedia sensors. The sensors are very restricted for resources, and cannot transmit a huge amount of media traffic; thus, the proposed model offers a QoS-aware routing algorithm, while considering the node statistics and user demands. In addition, mobile edges are utilized in the proposed model to overcome the delay factor, reducing the size of forwarding tables for sensors nodes. The mobile edges perform an interaction with both IoT nodes and the SDN controller by deployed switches and routers. The SDN controller decouples the control plane and data plane and fetches the store information from the control plane to manage the multimedia traffic with efficient data distribution and resource supervision. Moreover, the controller utilizes a threshold-based secret sharing scheme to increase the secrecy level among low level and boundary nodes. Such components support trustworthy communication from sensing nodes to network applications.