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The file download process over Internet is usually slow. This paper presents design and simulation of a distributed and co-ordinated file transfer protocol for the Internet applications. Presented approach, known as hybrid parallelized file transport protocol (HPFTP), consist of a centralized server that distributes the download process across multiple file servers based on QoS parameters as available...
In this paper, we introduce an IP multimedia sub-system (IMS) based testbed which provides a platform for the study of real-time services integration and orchestration. This open-source based testbed is built on the principle of service oriented architecture (SOA), with an emphasis for real-time network services. We further developed service-oriented system functionalities such as optical network...
Providing data as a service has not only fostered the access to data from anywhere at anytime but also reduced the cost of investment. However, data is often associated with various concerns that must be explicitly described and modeled in order to ensure that the data consumer can find and select relevant data services as well as utilize the data in the right way. In particular, the use of data is...
Defined by the 3GPP, the IP multimedia subsystem (IMS) is an architectural framework that enables the delivery of multimedia services in mobile networks. Based on the session initiation protocol, the IMS offers unified billing, QoS negotiation mechanisms, and the possibility of combining services deployed in different environments like CAMEL and Parlay OSA. With the aim of determining the real limitations...
Since the Internet of Services (IoS) is becoming reality, there is an inherent need for novel service selection mechanisms, which work in spite of large numbers of alternative services and take the user-centric nature of services in the IoS into account. One way to do this is to incorporate feedback from previous service users. However, practical issues such as trust aspects, interaction contexts...
Service creation by composing existing services and/or network resources is considered by Telecom and Internet industries as the trend for service provisioning in next generation networks. Related research work is being carried out for years, and various service composition approaches have been proposed by different standardization organizations and companies catering to different network requirements...
Mobile and nomadic devices such as cell phones and PDAs have evolved in recent years from resource constrained appliances to highly connected and increasingly powerful devices. This in turn has led to the development of standardized platforms most notably Windows mobile, Java micro edition, Android and the IPhone OS which enable third party developers to build applications fairly easy. Thanks to the...
Wireless mesh networks (WMNs) have attracted increasing attention and deployment as a high-performance and low cost solution to last-mile broadband Internet access. Wireless mesh networks have emerged as a potential technology for next-generation wireless networking. WMNs have been widely accepted in the traditional application sectors of ad hoc networks because of their advantages over other wireless...
Nowadays, how to efficiently compose Web services has become a hotspot. In this paper, we introduce a method of recommending an optimal service sequence based on the original service sequence for a composite service. This method uses a Bayesian-based approach and selects the service sequence that has the largest probability as the best choice. Compared with existing methods, this method has two advantages:...
Services participating in the composition are usually co-ordinated according to a workflow, composed by several activities, each of which carried out by a service. The binding of services to workflow activities may be affected by several parameters (e.g., QoS, price, reputation, etc.). In this paper, we propose a service binding driven by a further important requirement, that is, the incompatibilities...
In this paper, we present the design and the implementation of a test-bed for the Policy and Charging Control (PCC) system proposed in 3GPP TS23.203. Specifically, we use an IP multimedia call service example to demonstrate how to implement an advanced mobile service with policy and charging control in our test-bed. We show that the PCC system can handle the application-level session information and...
The poor performance of TCP, designed about 30 years ago, over high bandwidth-delay product connections has attracted much attention in the past few years. Some research work attempt to solve this problem by using innovative window estimations. The bursty nature of packet transmission has compounded the challenges in the problem. In this paper, we propose a new transmission protocol - Fairness Control...
Due to the complexity and time-variation of wireless channel, it is a great challenge to measure and estimate the channel quality accurately in wireless ad hoc network. To address this problem, we propose a link quality estimator which use the packet loss rate (PLR), round trip time (RTT), available bandwidth (ABW) at the sender and the feedback information from receiver to continuously tracks the...
The cognitive radio (CR) based IEEE 802.22 is a standard for wireless regional area networks (WRANs), which is allowed to utilize TV bands when no interference is present to incumbents (i.e. TV receivers and microphones). Compared to other existing networks, it has larger coverage range and provides broadband access in rural and remote areas with performance comparable to DSL and cable modems. It...
Because of rapid channel attenuation in lossy environment, there is a severe packet drop loss problem in wireless ad hoc networks. Though MIMO (Multi-Input Multi-Output) technology can alleviate this effect greatly, it will result in higher transmission energy depletion as using more transmit antennas. Lots of schemes have been proposed to reduce such energy cost by transmit antenna selection. However,...
Risk management is an important process for public service organizations to maintain a high quality of service. However, many organizations are not satisfied with the result from risk handling. This paper proposes changes to a risk management model by integrating service level agreements into it. This makes responsibilities more clear to all parties involved in risk management. This paper also introduces...
This paper presents a comparative analysis, set in Vanet scenarios and based on simulations, between the well-known IEEE 802.11p standard and an efficient slotted protocol based on RR-Aloha (MS-Aloha). Notably the chosen slotted protocol is completely distributed and based on reservation, and has been specifically designed to face issues typical of mobility, while preserving quality of service guarantee...
High concentration of users in a cell of a wireless LAN leads to an unsustainable traffic load at the access point (AP). An unsuitable solution to the problem will cause poor connectivity for users, severe performance degradation, and possible collapse of the wireless LAN. In this paper, we present a scheduler based on queue length at the AP and a congestion control scheme based on the channel utilization...
TCP, the facto standard used in today's Internet, has been found to perform poorly in Mobile Ad Hoc Networks (MANETs). This is exacerbated by contention with increasing UDP-based high priority multimedia traffic and the class differentiation introduced in current QoS protocols, which results into TCP starvation and increased spurious timeouts. In this paper, we propose a cross-layer TCP enhancement...
The Hybrid CDN-P2P architecture, or HCDN, which combines the complementary advantages of CDN and P2P networks, has been proposed to reduce the deployment cost and to improve the quality of service in file sharing and video streaming applications. A replica placement algorithm (RPA) decides where to replicate the specific data. Existing RPAs for pure CDN do not work efficiently in the HCDN architecture...
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