Mark Schulz

The iLab Shared Architecture: A Web Services Infrastructure to Build Communities of Internet Accessible Laboratories

The Massachusetts Institute of Technologys iLab project has developed a distributed software toolkit and middleware service infrastructure to support Internet-accessible laboratories and promote their sharing among schools and universities on a worldwide scale. The project starts with the assumption that the faculty teaching with online labs and the faculty or academic departments that provide those labs are acting in two roles with different goals and concerns. The iLab architecture focuses on fast platform-independent lab development, scalable access for students, and efficient management for lab providers while preserving the autonomy of the faculty actually teaching the students. Over the past two years, the iLab architecture has been adopted by an increasing number of partner universities in Europe, Australia, Africa, Asia, and the United States. The iLab project has demonstrated that online laboratory use can scale to thousands of students dispersed on several continents.

An update to the software architecture of the iLab Service Broker

The MIT iLab architecture (consisting of Lab Servers and Service Brokers) was designed in the 1990s and while the Lab Server was designed as a software service the same architectural approach was not adopted for the Service Broker. This paper reports on a redesign of the Service Broker as a software service, which is itself a collection of software services. In the process of this redesign it was decided to examine the API on the Lab Server and to support not only the existing Lab Server API (to maintain support for all existing iLab Lab Servers) but to concurrently support an alternative lightweight API based upon a RESTful architecture and to use JSON to encode the data. As these changes required a complete rewrite of the Service Broker code base, it was decided to experiment with an implementation of the services using Node.js - a popular approach to the implementation of servers in Javascript. The intention was to open up the code base to code developers normally associated with web development and not normally associated with the development of remote laboratories. A new software service named an “agent” was developed that wraps around the service broker to allow programmable modification of requests. The agent also has the ability to serve up an interface to user clients. The use of agents has advantages over existing implementations because it allows customised authentication schemes (such as OAuth) as well as providing different user groups with unique Lab Clients to the same Lab Servers. Lab Clients no longer are served up through the Service Broker, but can reside anywhere on the Internet and access the Service Broker via access to a suitable agent. One outcome of these architectural changes has been the introduction of a simple integration of a remote laboratory in the Blackboard Learning Management System (LMS) using a Learning Tool Interoperability (LTI) module for user authentication.

JAVA implementation of the Batched iLab Shared Architecture

The MIT iLab Shared Architecture is limited currently to running under Microsoft Windows. A JAVA implementation of the Batched iLab Shared Architecture has been developed that can be used on other operating systems and still interoperate with the existing Microsoft .NET web services of MITs iLab ServiceBroker. The JAVA implementation provides a 3-tier code development model that allows code to be reused and to develop only the code that is specific to each experiment.

Designing support for collaboration around physical artefacts: Using augmented reality in learning environments

The aim of this thesis is to identify mechanisms for supporting collaboration around physical artefacts in co-located and remote settings. To explore the research question in the project, a Research through Design approach has been adopted. A technology probe — an evolutionary prototype of a remote collaboration system — will be used to fuel the research. The prototype will facilitate collaboration between small groups around physical artefacts in an augmented learning environment. The prototype will inform future collaborative augmented reality technology design.

Real-time animation of equipment in a remote laboratory

Many remote laboratory setups include a webcam for users to observe the equipment in action. However, naïve users do not get a clear picture of what might be happening inside the equipment. This paper presents one attempt made to address this issue, using an animation to provide an exploded view of the equipment and to drive this animation with data streamed in real-time from the equipment. This is achieved with no change to the existing MIT iLabs Shared Architecture; an additional data path is utilized which does not affect existing software architectures.

A priority media access control protocol for video communication support on CSMA/CD LANs

Real-time multimedia communication applications demand performance requirements which differ significantly from conventional data communication applications. Current local area networks (LANs) provide efficient transport for bursty data traffic; however, they cannot necessarily provide quality of service guarantees for real-time communications. In this work we introduce and investigate an experimental priority protocol for supporting real-time communication on Ethernet, a popular implementation of multiple-access broadcast bus LANs. We examine the new protocol, known as Priority Mode-CSMA/CD (PM-CSMA/CD), providing a high priority (HP) class with CSMA/CD employed for standard priority (SP) traffic. PM-CSMA/CD performance is examined through computer simulation of videotelephony workstations operating over the shared bus LAN. Over all observed traffic conditions, the priority protocol provides performance satisfying real-time packet transport requirements of audio and video streams. The primary advantage of our protocol over similar priority schemes is its physical layer compatibility with standard CSMA/CD. The protocol also provides improved channel utilization with increasing high priority load, with no penalty in SP class performance at low to medium network loads.

RESTlabs: Service broker architecture for remote labs

This paper reports a work-in-progress at the Centre for Educational Innovation and Technology (CEIT) at The University of Queensland on the design and implementation of a new remote laboratory architecture utilizing contemporary and emerging web standards. The RESTlabs architecture maintains the concept of a Lab Server that manages a rig upon which to run experiments and a Service Broker to manage user access to a Lab Server. Much innovative design is taking place in the Lab Server and the UI associated with an experiment, and this requires new support architectures from the Service Broker. This paper discusses the design of a Service Broker as detailed in the MIT iLabs architecture and discusses the changes that have been incorporated in the RESTlabs architecture of the Service Broker.

Computer-aided selection of components for technology-independent specifications

The specification of a synchronous circuit can be given as a set of abstract building blocks that are interconnected. A set of fast algorithms are presented here for the selection of components that map each of these abstract building blocks to one of a number of suitable physical components. The first set of algorithms select the set of fastest or cheapest (smallest area) of all possible components. Another set of algorithms is given that will find a solution with user-defined constraints. These algorithms, which are implemented as part of the SPOT system, use a exhaustive list of timing information to increase the likelihood of a good solution. >

COTS embedded Internet platform and Blimp UAV for educational purposes

Easy, available and inexpensive modules like digital radio or modems and sensors allow the practical understanding of communication technology. We present a Commercial off the Shelf (COTS) Internet platform for teaching digital and wireless communications. Our experience showed that teaching embedded systems by building a realistic system is most convincing for students as it shows theory applied and engages students better then a more theoretical approach. We created an Internet platform development environment and a Blimp UAV that introduced wireless and digital communication systems, realtime OS and embedded networking concepts.