Figure 1. Layered framework of SaaS, Paas and, LaaS
Cloud computing is becoming a widely used technology nowadays. It has changed the way the applications and data area accessed. Rather than using personal computer or local server, cloud computing uses network of remote servers which is on the internet to manage, protect, and store. E-learning based on clouds is possible with a certain payment. It requires many hardware and softwares. By the use of cloud, the process of accessing data has changed a lot. E-learning service consumers like colleges and universities have to pay for the quality resources, utilized for actual duration of time. It is in the same way to pay the electricity bills and water bills according to consumption. This paper presents what cloud computing is, the issues concerning the implementation of cloud-based e-learning, and suggests architecture for elearning which can be used by educational institutes as well as by small and medium scale organizations.
Internet based learning process is e-learning. By using Internet it can better manage, design, implement, and support learning process. By using cloud many laboratories are moving on cloud known as virtual laboratories [7]. In universities and many small and medium scale organizations, it has been observed that resources become useless when the semester ends or when there are no projects on that particular platform and applications [5] . Those resources can be effectively used in e-learning process. For cost effectiveness and easy access e-learning is widely accepted by online learners. In e-learning service, consumers like colleges and universities have to pay for the quality of computing resources utilized for actual duration of time by the stakeholders. Proposed e-learning process offers one possible way to improve the learning process by using Cloud Computing. Benefits provided by e-leaning are better performance, more availability, and improved scalability, bigger cost cutting, and better return on investment.
Cloud computing is a resource pooling on the Internet which can be expanded and is accessible on-demand by many tenants. It is a practice to store, manage, and process the data instead of using a local server or a personal computer. This technology uses both hardware and software, and it reduces the cost to deliver a service over a network. The main advantage of cloud computing is that if something goes wrong in the cloud then organizations doesn't need to worr y about the infrastructure because it is the sole responsibility of provider. Users are free to use the resources provided. Mainly small and medium sized organizations that cannot afford to create and monitor permanent infrastructure are moving towards cloud computing.
According to Singh, Cloud computing is typically defined as a type of computing that relies on sharing computing resources rather than having local servers or personal devices to handle applications [8] .
Cloud computing is mainly of four types- Private, Community, Public, and Hybrid.
This cloud infrastructure is mainly for an organization and managed by the organization or a third party providing cloud computing [3] .
In this, the cloud is for specific community of consumers. It can be owned, managed, and operated by one or more organizations in the community, a third party or by combination [6].
In this model, the cloud is shared by multiple organizations and is supported by a specific community that has shared resources. It can be managed by the organization or a third party provider [6].
This model comprises two or more types of cloud and enables data, and application portability between the clouds. A hybrid academic cloud is an extension of private cloud in which valuable information of university is stored within their own infrastructure and other information or data is stored in public cloud by means of cloud service providers [2] . Some firms which do not want to completely move their IT to a public cloud due to various reasons, such as security, reliability, and availability can adopt this model.
In this section, the author has explained about service models, advantages of cloud based e-learning, and layered framework of educational cloud.
Cloud computing consists three service models which are SaaS (Software as a service), PaaS (Platform as a service), and IaaS (Infrastructure as a service). Figure 1 shows layered framework of SaaS, PaaS, and LaaS.
Figure 1. Layered framework of SaaS, Paas and, LaaS
SaaS is software delivery service, that provides service through Internet. Use of SaaS applications tends to reduce the cost of software ownership by removing the need for technical staff to install, manage, and upgrade software, as well as to reduce the cost of licensing software. SaaS applications are usually provided on a subscription model. SaaS Examples: Google Apps, Salesforce, Workday, Concur, Citrix GoToMeeting, Box, Dropbox, and Cisco WebEx.
PaaS provide a platform for developers. It works at lower level than SaaS. PaaS is built on top of virtualization technology. Businesses can get resources as they need them when scaling or demand grows. So it is better rather than investing in hardware with redundant resources. PaaS example: Apprenda, Heroku, Google App Engine, and Red Hat's OpenShift.
IaaS provides processing, storage, network, and fundamental computing resources [7] . IaaS is the most flexible cloud computing model and allows for automated deployment of servers, processing power, storage, and networking. IaaS clients have true control over their infrastructure than users of PaaS or SaaS services. The main uses of IaaS include the actual development and deployment of PaaS, SaaS, and web-scale applications. IaaS Examples: Amazon Web Services (AWS), Navisite, Cisco Metapod, Softlayer, Microsoft Azure, Joyent, Google Compute Engine (GCE), and Exoscale.
SaaS gives users automated and scalable environments with extreme flexibility and control, while PaaS provides a framework for quickly developing and deploying applications by automating infrastructure provisioning and management. Eliminating the need to install and run programs on individual devices, SaaS makes applications available through the internet.
There are several advantages of cloud based e-learning such as:
For the e-learning, a layered framework has been proposed for educational cloud. The objectives for collaborated educational cloud are:
Figure 2 shows layered framework of collaborated educational cloud. According to this proposed framework, top most layer is service consumption layer. Service consumption can be in the form of virtual laboratory access, research, and development, elearning, evaluation, or in academic administration.
Figure 2. Layered Framework of Collaborated Educational Cloud
Next layer is application resource pool. This layer consists of course management, programming interface, content development, content delivery, education process, moodle, e-mail, etc.
Third layer is platform resource pool and API layer. This layer consists of middleware, C++, SDK, IDE, content, messaging, and operating system.
Last layer is Information Communication and Technology (ICT) resource pool. This layer consists of storage, memory, CPU, database, and network.
So, this cloud framework can be used by a specific community of people to benefit them in both cost and education. The e-learning cannot completely replace teachers, it is only an update for technology, concepts, and tools, giving new content, concepts and methods for education. Therefore the role of teachers cannot be replaced [4].
This paper presents a layered framework of educational cloud. Given increasing importance to cloud computing, the application of this technology has become an important area of research. E-learning through cloud computing is a way to enhance the skills of people with the latest technologies available. E-learning has lot of advantages like low cost, diversity, flexibility, measurement, and many more. Virtualization technology separates the physical hardware from operating system [1] . Using cloud for e-learning can reduce the cost and increase effectiveness of learning. E-learning framework that has been proposed is an efficient way to provide elearning paradigm. The concept of e-learning environment through the use of a new technique such as cloud computing technology can be materialized in educational institutions in various stages. Academic institutions can benefit economically using cloud computing environment because of minimal cost for administration and maintenance.