# Model Mediation to Overcome Light Limitations--Toward a Secure Tactile Internet System
## 1 Introduction  
Tactile Internet is the future communication system that enables the communication of human sense of touch and actuation in a real time [1]. The conventional and traditional evolved communication networks fit a communication medium for transferring voice and data with certain performance. These systems represent either a form of human to human (H2H) communication or a machine to machine (M2M) communication; however, they do not cover the interaction between the human and the machine [2]. Tactile Internet provides a bilateral communication system able to transfer actuation and touch in a real time form between two distinct sides, mostly a human and a machine. This presents a new form of communication, which is the human to machine communication (H2M) [3]. Haptic communications can be enabled over the tactile Internet and thus, moving from the traditional content delivery to skill delivery [4]. Tactile Internet as teleoperated systems can be viewed as three main domains; the master domain, the network domain, and the slave domain as illustrated in Figure 1[5]. The first part is the master domain, which represents the human or the operator with one or more master devices. The master device is a haptic device with a certain degree of freedom (DoF). Haptic devices allow end users to feel, touch and manipulate objects in remote environment through an appropriate interface [6]. The sensation and interaction capabilities of the haptic device depend mainly on the DOF of the device. Haptic devices extract and track physical manipulations of the end user that represent the device inputs and fed the end user with real touch sensations as outputs. Haptic devices have inputs, such as position and orientation components, and outputs such as force and torque components. These devices differ in terms of DOF, mechanical bandwidth, workspace, possible inputs and outputs, interfaces, and maximum range of displayed force [7]. The second part is the slave domain, which is the remote domain that includes the slave device or the teleoperator operated in an environment. Remote environment may also deploy many slave devices that work together or independently to achieve common or different tasks [8]. Slave devices employ haptic devices with certain DoF, as well as the master devices. Table 1 introduces a list of common market available haptic devices with the main features and applications of each device. The mid domain is the network domain, which represents the medium for the haptic data to be transferred in a bilateral way. The network domain provides the infrastructure for transferring both haptic information data; kinesthetic and tactile data [9]. Kinesthetic data contains information about force and position, while tactile data contains touch information [10]. Figure 1: General structure of the tactile Internet system. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Device** & **Def** & \begin{tabular}{c} **Maximum** \\ **Procer/device at** \\ **Nominal Position** \\ \end{tabular}  & \begin{tabular}{c} **Stiffness** \\ **X,YZ** \\ \end{tabular}  & **Range of Motion** & **Characteristics** & **Applications** \\ \hline \hline \multirow{7}{*}{ \begin{tabular}{c} Touch [11]/ Commonized Touch [5] \\ **(Sensible Phantom Onman) [12]** \\ \end{tabular}  } & \multirow{7}{*}{6} & \multirow{7}{*}{3.3 N} & \begin{tabular}{c} 1.25 N/mm \\ 2.13 N/mm \\ 1.02 N/mm \\ \end{tabular}  & \multirow{7}{*}{**Range of Resolution**} & \multirow{7}{*}{**Characteristics**} & \multirow{7}{*}{**Applications**} \\  & & & & & & \\ \cline{4-7}  & & & & & & & \\ \cline{4-7}  & & & & & & & \\ \cline{4-7}  & & & & & & & \\ \cline{4-7}  & & & & & & & \\ \cline{4-7}  & & & & & & & \\ \cline{4-7}  & & & & & & & \\ \cline{4-7}  & & & & & & & \\ \hline \hline \multirow{7}{*}{ \begin{tabular}{c} Virtual 6D [14] \\ \end{tabular}