Design and realization of a middleware for mobile task coordination

The trend towards interconnection of applications has long been recognized as a key challenge for information systems design. Following this trend, organi- zations have developed and introduced many distributed systems with differ- ent functionalities. Furthermore, computing becomes today increasingly mobile; performances of mobile devices (i.e. PDAs and smartphones) as well as the expansion of high-speed mobile networks allows many tasks to be performed beyond stationary workspaces. The dramatic growth of stand-alone and partly incompatible applications will negatively affect the integration, coordination and communication for entire so- lution. Contemporary solutions focus on stationary systems only; the usage of mobile devices is limited to simple scenarios (i.e. information access). In order to support the seamless integration of mobile devices, future distributed solutions should take services and service meta-information into account (e.g. variation of network bandwidth, battery power, availability, connectivity, reachability, sensors data and locations of services and service providers). In this master thesis we want to analyze how a distributed environment with va- riety of separated (mobile) service providers - implemented with different tech- nologies - can be integrated and coordinated. Finding compromises between performance, comfort and intelligent intercommunication is the main goal of this thesis. Therefore, it is concentrated on the conceptualization and design of a central middleware component that provide the coordination and communication functionalities for stationary and mobile entities. In order to prove some possible communication scenarios, the thesis provides a middleware-based scenario

RESTful Wireless Sensor Networks

Sensor networks have diverse structures and generally employ proprietary protocols to gather useful information about the physical world. This diversity generates problems to interact with these sensors since custom APIs are needed which are tedious, error prone and have steep learning curve. In this thesis, I present RESThing, a lightweight REST framework for wireless sensor networks to ease the process of interacting with these sensors by making them accessible over the Web. I evaluate the system and show that it is feasible to support widely used and standard Web protocols in wireless sensor networks. Being able to integrate these tiny devices seamlessly into the global information medium, we can achieve the Web of Things

Dependable IPTV Hosting

This research focuses on the challenges of hosting 3rd party RESTful applications that have to meet specific dependability standards. To provide a proof of concept I have implemented an architecture and framework for the use case of internet protocol television. Delivering TV services via internet protocols over high-speed connections is commonly referred to as IPTV (internet protocol television). Similar to the app-stores of smartphones, IPTV platforms enable the emergence of IPTV services in which 3rd party developers provide services to consumer that add value to the IPTV experience. A key issue in the IPTV ecosystem is that currently telecommunications IPTV providers do not have a system that allows 3rd party developers to create applications that meet their standards. The main challenges are that the 3rd party applications must be dependable, scalable and adhere to service level agreements. This research provides an architecture and framework to overcome these challenges

POLICY-BASED MIDDLEWARE FOR MOBILE CLOUD COMPUTING

Mobile devices are the dominant interface for interacting with online services as well as an efficient platform for cloud data consumption. Cloud computing allows the delivery of applications/functionalities as services over the internet and provides the software/hardware infrastructure to host these services in a scalable manner. In mobile cloud computing, the apps running on the mobile device use cloud hosted services to overcome resource constraints of the host device. This approach allows mobile devices to outsource the resource-consuming tasks. Furthermore, as the number of devices owned by a single user increases, there is the growing demand for cross-platform application deployment to ensure a consistent user experience. However, the mobile devices communicate through unstable wireless networks, to access the data and services hosted in the cloud. The major challenges that mobile clients face when accessing services hosted in the cloud, are network latency and synchronization of data. To address the above mentioned challenges, this research proposed an architecture which introduced a policy-based middleware that supports user to access cloud hosted digital assets and services via an application across multiple mobile devices in a seamless manner. The major contribution of this thesis is identifying different information, used to configure the behavior of the middleware towards reliable and consistent communication among mobile clients and the cloud hosted services. Finally, the advantages of the using policy-based middleware architecture are illustrated by experiments conducted on a proof-of-concept prototype

Scalable Reliable SD Erlang Design

This technical report presents the design of Scalable Distributed (SD) Erlang: a set of language-level changes that aims to enable Distributed Erlang to scale for server applications on commodity hardware with at most 100,000 cores. We cover a number of aspects, specifically anticipated architecture, anticipated failures, scalable data structures, and scalable computation. Other two components that guided us in the design of SD Erlang are design principles and typical Erlang applications. The design principles summarise the type of modifications we aim to allow Erlang scalability. Erlang exemplars help us to identify the main Erlang scalability issues and hypothetically validate the SD Erlang design

A survey of communication protocols for internet of things and related challenges of fog and cloud computing integration

The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This article surveys e application layer communication protocols to fulfill the IoT communication requirements, and their potential for implementation in fog- and cloud-based IoT systems. To this end, the article first briefly presents potential protocol candidates, including request-reply and publish-subscribe protocols. After that, the article surveys these protocols based on their main characteristics, as well as the main performance issues, including latency, energy consumption, and network throughput. These findings are thereafter used to place the protocols in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their choice, interoperability, and wider system integration. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture.Peer ReviewedPostprint (author's final draft

ENABLING MOBILE DEVICES TO HOST CONSUMERS AND PROVIDERS OF RESTFUL WEB SERVICES

The strong growth in the use of mobile devices such as smartphones and tablets in Enterprise Information Systems has led to growing research in the area of mobile Web services. Web services are applications that are developed based on network standards such as Services Oriented Architecture and Representational State Transfer (REST). The mobile research community mostly focused on facilitating the mobile devices as client consumers especially in heterogeneous Web services. However, with the advancement in mobile device capabilities in terms of processing power and storage, this thesis seeks to utilize these devices as hosts of REST Web services. In order to host services on mobile devices, some key challenges have to be addressed. Since data and services accessibility is facilitated by the mobile devices which communicate via unstable wireless networks, the challenges of network latency and synchronization of data (i.e. the Web resources) among the mobile participants must be addressed. To address these challenges, this thesis proposes a cloud-based middleware that enables reliable communication between the mobile hosts in unreliable Wi-Fi networks. The middleware employs techniques such as message routing and Web resources state changes detection in order to push data to the mobile participants in real time. Additionally, to ensure high availability of data, the proposed middleware has a cache component which stores the replicas of the mobile hosts’ Web resources. As a result, in case a mobile host is disconnected, the Web resources of the host can be accessed on the middleware. The key contributions of this thesis are the identification of mobile devices as hosts of RESTful Web services and the implementation of middleware frameworks that support mobile communication in unreliable networks