Fifth-generation (5G) envisages a “hyper-connected society” where an enormous number of diverse entities could communicate with each other anywhere and at any time, some of which will demand extremely challenging performance requirements such as sub-millisecond latency, and higher data rates. Cloud-enabled radio access networks (CE-RANs) where intelligence is placed at the edge of the mobile network and in the proximity of end users emerge as a promising solution to improve online experience. To make CE-RAN more flexible and cost-effective, network functions virtualization and software defined networking technologies are employed, enabling features such as resource pooling, scalability, spectral efficiency, and multi tenancy. The accommodation of such technologies in the context of 5G requires multipronged efforts at various levels, in particular at the management and orchestration. Among all topics that falls into this subject, e.g., resource optimization and efficient lifecycle management, this paper focuses on two critical challenges, i.e., service mapping and quality of service assurance. Particularly, the proposed service placement solution takes into account two main constraints, i.e., quality of user experience and limited hardware capabilities available at the network edge. Simulation tools as well as the SESAME testbed have been used to extract results in this paper and a proof-of-concept evaluation is presented.

P2P streaming today is one of the most challenging techniques to deliver real-time streaming on the Internet. Incentive mechanisms make a crucial part of the P2P algorithms in order to avoid uncooperative and eliminate malicious behavior. In this paper we present a monetary incentive mechanism based on the taxation incentive schemes. We use a model of a P2P streaming service to apply the idea and validate the quantitative effect on both the users' and the provider's welfare in the system. A billing model based on QoS levels for the perceived video that offers a remuneration inventive for the cooperative users, contributes to the P2P streaming because of the two main reasons: increases provider's welfare in terms of monetary benefit and saves infrastructure cost; increases users' welfare in terms of increased cooperation and motivation to participate in the streaming.

This paper proposes a new methodology focused on implementing cost effective architectures on Cloud Computing systems. With this methodology the paper presents some disadvantages of systems that are based on single Cloud architectures and gives some advices for taking into account in the development of hybrid systems. The work also includes a validation of these ideas implemented in a complete videoconference service developed with our research group. This service allows a great number of users per conference, multiple simultaneous conferences, different client software (requiring transcodification of audio and video flows) and provides a service like automatic recording. Furthermore it offers different kinds of connectivity including SIP clients and a client based on Web 2.0. The ideas proposed in this article are intended to be a useful resource for any researcher or developer who wants to implement cost effective systems on several Clouds.

The number of online real-time streaming services deployed over network topologies like P2P or centralized ones has remarkably increased in the recent years. This has revealed the lack of networks that are well prepared to respond to this kind of traffic. A hybrid distribution network can be an efficient solution for real-time streaming services. This paper contains the experimental results of streaming distribution in a hybrid architecture that consist of mixed connections among P2P and Cloud nodes that can interoperate together. We have chosen to represent the P2P nodes as Planet Lab machines over the world and the cloud nodes using a Cloud provider's network. First we present an experimental validation of the Cloud infrastructure's ability to distribute streaming sessions with respect to some key streaming QoS parameters: jitter, throughput and packet losses. Next we show the results obtained from different test scenarios, when a hybrid distribution network is used. The scenarios measure the improvement of the multimedia QoS parameters, when nodes in the streaming distribution network (located in different continents) are gradually moved into the Cloud provider infrastructure. The overall conclusion is that the QoS of a streaming service can be efficiently improved, unlike in traditional P2P systems and CDN, by deploying a hybrid streaming architecture. This enhancement can be obtained by strategic placing of certain distribution network nodes into the Cloud provider infrastructure, taking advantage of the reduced packet loss and low latency that exists among its datacenters.

Since its appearance, peer-to-peer technology has given raise to various multimedia streaming applications. Today, cloud computing offers different service models as a base for successful end user applications. In this paper we propose joining peer-to-peer and cloud computing into new architectural realization of a distributed cloud computing network for multimedia streaming, in a both centralized and peer-to-peer distributed manner. This architecture merges private and public clouds and it is intended for a commercial use, but in the same time scalable to offer the possibility of non-profitable use. In order to take advantage of the cloud paradigm and make multimedia streaming more efficient, we introduce APIs in the cloud, containing build-in functions for automatic QoS calculation, which permits negotiating QoS parameters such as bandwidth, jitter and latency, among a cloud service provider and its potential clients.