**1. Introduction**

236 Telecommunications Networks – Current Status and Future Trends

Zhao, Y.; Qi, B.; Ma, X.; Lo, H.-K. & Qian, L. (2006a). Simulation and implementation of

Zhao, Y.; Qi, B.; Ma, X.; Lo, H.-K. & Qian, L. (2006b). Experimental Quantum Key Distribution with Decoy States, *Physical Review Letters*, Vol.96, No.7, 070502.

*International Symposium on Information Theory*, pp. 2094–2098.

decoy state quantum key distribution over 60 km telecom fiber, *Proceedings of IEEE* 

Actuality, Internet provides a convenient way to develop a new communication technology for several applications, for example remote laboratories. The remote access to complex and expensive laboratories offers a cost-effective and flexible means for distance learning, research and remote experimentation. In the literature, some works propose platforms based on the Internet in order to access experimental laboratories; nevertheless it is necessary that the platform provides a good architecture, clear methodology of operation, and it must facilitate the integration between hardware (HW) and software (SW) elements. In this work, we present a platform based on "multitier programming architecture" which allows the easy integration of HW and SW elements and offers several schemes of telepresence: teleoperation, telecontrol and teleprogramming.

The remote access to complex and expensive laboratory equipment represents an appealing issue and great interest for research, learning education and industrial applications. The range potentially involved is very large, including among others, applications in all fields of engineering (Restivo et al., 2009; Wu et al., 2008).

It is well known that several experimental platforms are distributed in different laboratories in the world, and all of them are on-line accessible through the Internet. Since those laboratories require specific resources to enable a remote access, several solutions for harmonizing the necessary software and hardware have been proposed and described. Furthermore, due to their versatility, these platforms provide user services which allow the transmission of information in a simply way, besides being available to many people, having many multimedia resources.

The potentiality of remote laboratories (Gomez & Garcia, 2007) and the use of the Internet, as a channel of communication to reach the students at their homes, were soon recognized (Basigalup et al., 2006; Davoli et al., 2006; Callangan et al., 2005; Imbre & Spong, 2006; Rapuano & Soino, 2005).

Several works based on remote experimentation, which are used as excellent alternatives to access remote equipment, have been published (Costas et al., 2008).

Web-Based Laboratory Using Multitier Architecture 239

This work is organized as follows: In Section 2, definitions and concepts used in this work about tele-control, tele-operation and tele-programming are introduced. In Section 3, the proposed scheme based on multitier architecture is presented. The laboratory server description is given in Section 4. In Section 5, two applications of the platform are presented. The first application concerns the remote experimentation of an induction motor located in the IRCCyN laboratories in Nantes; France. The second application consists of the remote experimentation of the manipulator robot located in the CIIDIT-Mechatronic laboratories in Monterrey; Mexico. Finally, in Section 6, conclusions and recommendations are given.

Now, we introduce the concepts of teleoperation, telecontrol and teleprogramming, which

**Teleoperation** is defined as the continuous, remote and direct operation of equipment (see figure 2). From the introduction of teleoperation technology, it made possible the development of interfaces capable of providing a satisfactory interaction between man and experimental equipment. On the order hand, the main aim of **telecontrol** is to extend the distance between controller devices and the equipment to the controller. Thanks to the development of the Internet, the distance between controller devices and the equipment has

*Structure of the work* 

**2. Some concepts** 

will be used in the sequel.

been increased (see figure 2).

Fig. 2. Telecontrol, teleoperation and teleprogramming schema.

Then, to solve the problem of testing engineering algorithms in real-time, we apply the advantages of the computer Network, computer communication and teleoperation. Furthermore, developing these new tools give the possibility to use these equipments for remote education.

In remote experimentation there exists several schemes based on the communication channel called **telepresence schemes**, some of them are: i) **teleoperation**, ii) **teleprogramming** and iii) **telecontrol**. In (Wang & James, 2005) some concepts are related with teleoperation. In other works, (Huijun et al., 2008) analyze the time-delay in the telecontrol systems, and (Cloosterman et al., 2009) studies the stability of the feedback systems with With Uncertain Time-Varying Delays. Others authors propose platforms only to move remote equipment, for example robots, (Wang & James, 2005). Finally, few works talking about the remote programming are published; see for instance (Costas et al., 2008).

However, for a remote laboratory to be functional, it must be capable of offering different schemes of telepresence. This can be easily understood from figure 1 which is an extension of the figure given in (Baccigalup et al., 2006). A comparison between different teaching methods, taking into account the teaching effectiveness, time and cost per students, is schematized in figure 1.

Fig. 1. Comparison between local and remote laboratories.

#### *Contribution*

Considering figure 1, the goal of this work is to introduce a platform called *Teleoptions*, which offers an alternative for remote laboratories, using three of the *telepresence schemes*: teleoperation, telecontrol and teleprogramming.

The main feature of this framework is its multitier architecture, which allows a good integration of both hardware (HW) and software (SW) elements.

#### *Structure of the work*

238 Telecommunications Networks – Current Status and Future Trends

Then, to solve the problem of testing engineering algorithms in real-time, we apply the advantages of the computer Network, computer communication and teleoperation. Furthermore, developing these new tools give the possibility to use these equipments for

In remote experimentation there exists several schemes based on the communication channel called **telepresence schemes**, some of them are: i) **teleoperation**, ii) **teleprogramming** and iii) **telecontrol**. In (Wang & James, 2005) some concepts are related with teleoperation. In other works, (Huijun et al., 2008) analyze the time-delay in the telecontrol systems, and (Cloosterman et al., 2009) studies the stability of the feedback systems with With Uncertain Time-Varying Delays. Others authors propose platforms only to move remote equipment, for example robots, (Wang & James, 2005). Finally, few works talking about the remote programming are published; see for instance (Costas et al., 2008). However, for a remote laboratory to be functional, it must be capable of offering different schemes of telepresence. This can be easily understood from figure 1 which is an extension of the figure given in (Baccigalup et al., 2006). A comparison between different teaching methods, taking into account the teaching effectiveness, time and cost per students, is

remote education.

schematized in figure 1.

*Contribution* 

Fig. 1. Comparison between local and remote laboratories.

integration of both hardware (HW) and software (SW) elements.

teleoperation, telecontrol and teleprogramming.

Considering figure 1, the goal of this work is to introduce a platform called *Teleoptions*, which offers an alternative for remote laboratories, using three of the *telepresence schemes*:

The main feature of this framework is its multitier architecture, which allows a good

This work is organized as follows: In Section 2, definitions and concepts used in this work about tele-control, tele-operation and tele-programming are introduced. In Section 3, the proposed scheme based on multitier architecture is presented. The laboratory server description is given in Section 4. In Section 5, two applications of the platform are presented. The first application concerns the remote experimentation of an induction motor located in the IRCCyN laboratories in Nantes; France. The second application consists of the remote experimentation of the manipulator robot located in the CIIDIT-Mechatronic laboratories in Monterrey; Mexico. Finally, in Section 6, conclusions and recommendations are given.
