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Faculty of Computer Science, Multimedia and Telecommunications
Teaching resources

Laboratories

In the Faculty of Computer Science, Multimedia and Telecommunications (EIMT, Estudis d’Informtica, Multimedia i Telecomunicaci) at UOC there are three typologies of degrees: Computer Science Engineering, Multimedia and Telecommunication Engineering. All of them are based on a fully online education, thus the laboratory is a key element to acquire the related practical competences.

The aim of the developed laboratory is to make possible the acquisition of the needed practical competences of the degrees of EIMT both using real hardware and software in an online environment. Therefore, the main efforts have been conducted on the development of both laboratory activities and the creation of the infrastructure to make it possible.

This laboratory consists of two different typologies, depending on the way to access the laboratory resources, i.e. locally, in which all resources are at students’ home, or remotely, by means of Internet access: Home Lab and Remote Lab respectively. Both of them imply the use of real hardware (e.g. electronic circuits assembling and measurement systems) and software (e.g. simulations or computer programming), thus the students can achieve practical competences in a distance-based learning environment by means of experimentation. For example, in Home Lab students receive at their home different software and electronic systems to carry out computer programs and experiments about electronics. The Remote Lab is remotely accessible by Internet, making possible to experiment with high cost and complex devices unavailable to students otherwise. In addition, we avoid misconfigurations due to a bad use of the devices and make the manipulation of them safer. Regarding access laboratory, Home Lab typology let students use all resources when they need them.

Nevertheless, the access to Remote Lab must be managed by means of a booking system or batch queues because all available resources are shared among students, subjects and degrees. Thanks to the use of these kinds of typologies, the access to the laboratory is 24x7 available. Laboratory and typologies details are described as follows. On one hand, Home Lab is shown, taking into account different kinds of experiments carried out. On the other hand, Remote Lab is presented, emphasizing the student’s access, resources and how it is used among different knowledge fields.

Home Lab

In this laboratory typology all students have all the needed resources in their home, since they are sent to them when they are enrolled in the related subject. These resources can be both real hardware and software, so students can use electronic equipment and software when they need them during the study. They can use these experimental resources along with a textbook during the learning process.

In terms of real hardware, we send to students different electronic systems to acquire practical competences by means of a fully hands-on lab.

Laboratory use cases: real hardware

Next, different knowledge fields, where real hardware is used, are described, presenting the used hardware and the main aim of use for each one.

Analogue Electronics

Analogue Electronics experiments are carried out by using Lab@Home, an electronic circuits assembling and measurement system developed by UOC for the learning of Electronics Engineering concepts in the Telecommunication Engineering related degrees. This system provides elements to develop processes and features of a traditional electronics laboratory on a single platform at a reduced cost and under good conditions for portability, providing the main features of a traditional electronics laboratory: circuits assembling, testing, measurement procedures or signal acquisition. This system has a user module with a switch, a multiturn potentiometer, a push button and a protoboard, which allows the student to assembly electronic circuits on it and access to 12 V, ±5 V and ±15 V DC power supplies, signal generation input and digital oscilloscope channels. Both signal generation and digital oscilloscope are software implementations and are controlled from the student’s computer connected to the board by means of a USB connector. Moreover, a set of electronics components like resistors, capacitors, inductors, diodes, LEDs, transistors and operational amplifiers, among others, are also included in the sent kit. Finally, in order to try a real measurement device, a multimeter is also added to this kit.

 
Design interaction, human-computer interaction and usability

Experiments related to design interaction, human-computer interaction and usability are conducted by means of the use of Arduino and Processing. An Arduino Starter Kit is sent to the students’ home, containing an Arduino board, batteries, a USB cable, potentiometers, light and temperature sensors, LEDs, resistors and a protoboard. Students experiment with the kit to develop new prototypes and new ways of interaction among computers, Internet and the real world.

Embedded systems

Students can conduct experiments about embedded systems using Arp@Lab. With this hands-on lab, students explore embedded systems and wireless sensor networks from an experimental point of view. No prior knowledge is needed, other than (very) basic C and some wireless networking theory. After this course, they are able to program a microcontroller and a radio chip, and to implement state-of-the-art applications and protocols for Wireless Sensor Networks.

Laboratory use cases: software

These experiments use both commercial and non-commercial software, oriented to cover different knowledge fields, as can be seen as follows.

Signal processing, electronics and communications

In this knowledge field a variety of software is used to perform different experiments. MATLAB software is used in signal processing and communications experiments. Other important software, extended in industry, is Agilent ADS, used in microwave applications. Moreover, other involved software is PSPICE for analogue electronics simulation, Quartus II for digital electronics developments or Opnet for networking experimentation.

Audio production

Audio production experiments are carried out by means of a “Virtual Mixing Table”. The virtual mixing table is a digital resource that simulates a market based 3D mixing table for professional audio recording, audio mixing and production. This software simulates one line and two microphone inputs, different presets for recording room scenarios, phantom button, channels volume, master volume and equalization for low/medium/high frequencies in real time.

Digital circuit design

Students use the UOC’s software development named VerilUOC, a self-study platform for learning digital circuit design, to acquire the competences related to the design of digital circuits. This platform provides a graphical user interface to facilitate the design and simulation of logic circuits. An automatic verification service using model checking is provided to check if the solution designed by the student is equivalent to the solution proposed by the instructor. If there is a difference between the behaviour of both solutions, the verification service automatically produces a meaningful feedback that points out the error without inform them about the final solution. This activity lab is between Home and Remote Lab, because the software is run in the student’s PC and the verification is run in a remote server.

Remote Lab

In terms of Remote Lab practical experiments, this laboratory typology needs to take into account some special considerations. Firstly, all resources used by students are physically placed in the University installations, therefore all resources are accessed in a remote way using Internet and no physical access exists among student and laboratory resources. Secondly, some specialized electronic devices are time-constrained because the number of devices is limited. Therefore, they can only be accessed by one student at the same time and they are shared among them (including among subjects and degrees), thus it is necessary to control the access to them using a booking system. Thirdly, some kind of experiments related to HPC (High Performance Computing) are time-constrained because concurrence must be avoided, thus, in this case, batch queues are used when servers are accessed. Finally, usability of the laboratory and how the experimentation must be conducted to acquire practical competences using this kind of laboratory must be considered.

   

With regard to the building infrastructure, the laboratory is installed in the 22@ Barcelona UOC’s building, separated into two different spaces to host all resources. On one hand a space is destined to keep all servers infrastructure (rack, switch, KVM). On the other hand, another space keeps the rest of specialised electronic devices such as communications equipment, digital electronics and so on; which are connected to PCs to be remote accessed and controlled. All available space is devoted to the continuous operation, then the next points are taken into account:

  • Access. Students’ access to the electronic hardware is controlled by means of a booking system, managing who access to each device and how much time each student can be connected to it. In the case of server’s room, the access can be controlled by means of their own operating
  • Temperature. Temperature and air flow are controlled by means of air conditioning systems to ensure a correct operation of all devices and avoid energy consumption.
  • Energy. Each room has available a UPS (Uninterruptible Power Supply) to ensure that all devices can operate although some problem occurs with the power grid. Moreover, using PDU (Power Distribution Unit) each outlet can be independently managed in order to power on/off hardware resources depending on their scheduled use.
  • Connectivity. Laboratory is connected to a Gigabit network using firewall security policies. The status of the network use, disk space and CPU load or energy consumption is managed in a centralised way.
  • Illumination. Efficient LED illumination is available for those experiments that need to be followed by students using web-cams.
  • Monitoring. All activity in the laboratory is monitored and logged, such as network use, disk space, CPU load or energy consumption. For example servers are monitored continuously and if some error occurs an alert is generated. Regarding the specialised electronic devices, for example student’s access is logged by means of the booking system. Moreover, electronic resources can be reset by using a PDU, then each device can be remotely managed and all events are logged.

According to the online learning environment, the required building space is minimised due to students have not to access to the laboratory physically since they are working in a remote way (or in their home). Moreover the same experimentation space can be used to N different kind of experiments and be shared among subjects and degrees. In addition, there exists a second degree of space minimisation by using machines virtualisation, since more than one virtual machine can be hosted in a real device.

Regarding the available resources, we estimate the necessity of devices, servers, software licences, and so on, taking into account the concurrent access to the resources. The use of the booking system in the case of electronic devices let us access to the resources according to an access policy, e.g. maximum time of experiment. Moreover, if some electronic board is necessary can be added to the laboratory and registered in the booking system. Real hardware is a time-constrained kind of resource where only one user can experiment with it at the same time, and then the booking system makes available its use.

This is useful to improve the efficiency of the laboratory since resources can be accessed 24x7 in one or more subjects at the same time, and the use of them can be scaled according to the needs of use.

Finally, in relation to usability and experiments design, different prototypes are developed and evaluated, with the final aim of integrating the laboratory resources into UOC’s virtual classrooms.

Given that, students will be working in the same virtual environment, being more natural for them the use of the laboratory as another learning resource (like a textbook). Moreover, at the end of each course a questionnaire is send to the students. With their answers different improvements are considered to evaluate the necessity of infrastructure/resources (scaling), design the needed resources (modelling), improve the availability of laboratory (scheduling), and, in general terms, improve the teaching-learning process by the innovation of using practical experiments along with theoretical contents.

Laboratory use cases: real hardware

Next, real hardware related experiments for different knowledge fields are presented.

Signal generation and measurement

Signal generation and measurement experiments can be carried out by using real complex laboratory equipment that could be found in any electronics lab, with the characteristic of being remotely accessible. Some of these devices are Agilent Technologies equipments such as arbitrary signal generator, oscilloscope or a vector signal analyser.

Analogue electronics

These experiments are destined to assemble different kind of electronic circuits by using Agilent Technologies switching matrices, electronics components and generator/measurement devices, an original way of let students mount their own electronic circuits in online education.

Digital electronics

Digital electronics experiments are carried out by using a real FPGA board in which students can load a VHDL code and try it in a real device. These experiments use a National Instruments FPGA board along with LabVIEW based interface in order to control the user interaction with the loaded VHDL code.

Communications systems

These experiments are oriented to let students practise different concepts of telecommunication engineering. A variety of devices are used with different aims: i) NI Elvis II+ is used along with Emona DATEx and Emona FOTEx to carry out communications systems and fibre optic related experiments, ii) USRP 2920 bundles are available for complex practise of radiocommunications protocols and signals transmission, and iii) Tablets and smartphones are used to load students applications in real devices. In addition, the use of switching matrices improves the experiments flexibility (student experimentation) and makes easier the laboratory managing (experiments preparation).

Switch and router configuration

A network topology, exclusively composed by real Cisco switches ad routers, is available for devices configuration experiments. Students are connected using a web browser and a telnet applet to configure real devices. These experiments provide great advantages, compared to simulators, since all IOS accepted commands are supported, and not only a subset. Furthermore, it is also possible to provide support to special operation modes, such as ROM monitor or password recovery, which require cold boots and interacting with the device's power source.

Laboratory use cases: software

Regarding software related experimentation, this is conducted in the following knowledge fields.

Web servers

Each student access to an Amazon VM and have to configure it according to a defined parameters in order to host an e-commerce website with some social network services.

Network and computer security

Students can practise attack’s methods by connecting remotely with different VMs as a local network was. Thus, they can login at them and make different kind of experiments:

  • Apache vulnerabilities
  • Windows vulnerabilities
  • A web page with XSS, SQLinjection, blind SQLinjection and Path Transversal vulnerability, and iv) Study of techniques implemented in some malware by using Honeypot.
Distributed systems and protocols and applications

UOC's students and researchers use PlanetLab global network of computers to test network and distributed systems protocols and applications in a real environment. As at December 2011, PlanetLab was composed of 1024 nodes at 530 sites worldwide.


Mathematics

Maths students need to practise for acquiring the required skills. In an ideal situation, the needed exercises to acquire all competences would be personalised by a tutor according to the work carried out by the student in class. Our initiative aims to simulate a remote tutor through the implementation of customized exercises, their correction and what have gone wrong with students’ resolution.

Conclusions

Taking into account the work conducted on the laboratory design, infrastructure creation and experiments development, several are conclusions can be extracted, considering the opportunities of using this kind of laboratory in an online education environment and the benefits of using it. Next, the key ideas for the presented laboratory are summarised:

  • Experimentation with real hardware and software in an online education environment. Both commercial and non-commercial software is used and, both UOC’s hardware developments and widely used devices by industry are available.
  • Laboratory resources are shared among students/subjects/degrees, minimising costs and taking advantage of existing experiments and devices. About 6000 students were enrolled in EIMT degrees during the 2013 year, so all of them will be able to access to the 24x7 available resources from their home by using Home Lab or Remote Lab typologies, according to their learning needs.
  • Time-constrained real hardware, due to only one user can use it at the same time, can be accessed by using a booking system or batch queues depending on the experiments requirements. In this way the use of hardware is more efficient by accessing 24x7, so the same device is shared among students/ subjects/degrees at the same time and the experiments can be scaled according to the real hardware necessities of each course (i.e. enrolled students or number of practical experiments).
  • Experiments could be shared among institutions by using the booking system (registering new devices) or, if it was necessary, by using the same LTI specification (Learning Tools Interoperability specification promoted by ISM Global Learning Consortium) used by UOC (provider/consumer). This possible sharing infrastructure would have an effect on the need of space and number of laboratory resources and in the management, due to each institution could be specialised in different resources.
  • By accessing in a remote way or by working with the Home Lab, the necessary space for the laboratory infrastructure is lower than in a face-to-face education context because students have not to access physically in it, density of devices in the same space can be higher and different devices can be shared among subjects and degrees using the same physical space. The need of resources in the laboratory is lower than a traditional one and the access to them is higher, because it is possible a 24x7 access and all resources can be balanced among subjects and degrees when necessary. In addition, a second degree of space needs reduction is obtained by means of virtualization, obtaining more than a 4 factor of reduction for server necessities with similar characteristics devices (the more quality of servers, the more reduction of real equipment).
  • Benefits for the infrastructure maintenance are twofold: i) consumption energy is minimised by using  low consumption devices (LED illumination), PDU equipment (power on/off) and temperature control;  ii) laboratory monitoring allows knowing the energy consumption, CPU load, network use and disk  space, then actions can be performed by administrator. Moreover, all this monitoring process could be used during an external audit.
  • With the available information about the use of laboratory (e.g. in the remote typology) it is possible  to foresee the necessity of infrastructure (scaling), to know the use of resources (modelling), to  improve the laboratory availability (scheduling), and, in general terms, improve the teaching-learning  process by the innovation of using practical experiments along with theoretical contents (learning  resources improvement).