Enhancing NGN's versatility for Multi-Service support: The Bridging Virtualization approach
ABSTRACT Since the appearance of next generation networks (NGN), access and aggregation networks (even core networks) have suffered significant improvements and architectural evolutions. The idea of network convergence, something in which providers are very interested, is closely related with these deployments, as the same network must be capable of transporting all the existent telecommunication services (voice, video and data). This paper introduces an architectural model which is based on broadband forum technical recommendations for multi-service (TR-058), and makes use bridging technology in all the nodes. In this model, carrier-class Ethernet has been selected as transport technology in order to achieve convergence in provider networks. Then, a radically new approach for network convergence is presented, bridging virtualization. This approach introduces the concept of instances to differentiate service requests. Finally, a secure alternative to the instantiation of multiple services is presented (EAPOL-in-EAPOL).
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ABSTRACT: Internet has been developing for more than three decades ago. Considering its popularity, ubiquity and scale, it causes immense difficulty for other networks with different architectures to be deployed or even get adequately evaluated. This paper introduces a core/edge separation based architecture model, which allows core networks with various architectures to coexist, enables end users to choose whichever core network at will, and simplifies the design, deployment, operation and management of edge networks. In this model, Carrier Grade Ethernet, which is still on-going evolving, is selected as transport technology in the edge networks. A radically new approach called Bridging Virtualization is used to form a convergent access platform to these different core networks for end users. Besides the increasing flexibility for the edge transport carriers, this model also improves end users' independence from the access provider. Moreover, it makes it possible the execution of network convergence step-by-step and can be used to realize it in the edge first. Finally, we apply this architecture model to design the campus networks of Tsinghua University, analyze its pros and cons and make some conclusion.
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ABSTRACT: AWiMax system integrates a number of new technologies, such as multiantenna technologies and adaptive modulation and coding schemes. Those new technologies potentially deliver high data rates that can satisfy customer requirements. However, proper optimization is necessary for system design to achieve the desired superior performance. This chapter discusses the optimization procedure of a WiMax system from various aspects and particularly the radio resource allocation optimization and scheduling optimization. The radio resource allocation includes the optimization of modulation and coding scheme, MIMO modes, power control and allocation and link adaptation. In scheduling optimization, several service and multi-user scheduler mechanisms used in a WiMax system are discussed. WiMax QoS policy is also presented for the scheduling optimization. Finally, several system-level experiments are presented. The experiment results show that proper optimization can boost the system throughput and satisfy various performance requirements.12/2010: pages 295-319;
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ABSTRACT: This chapter provides an introduction to the basic concepts of a wireless communication system. First, a simple point-to-point wireless link is considered and the key techniques at the transmitter and receiver that are required for a successful communication are discussed. The wireless medium being inherently a shared medium, multiple access methods to support numerous users in a given area is critical. This chapter also discusses several multiuser communication schemes. Specifically, two popular multiuser transmission strategies - CDMA and OFDM, are described and their merits and challenges discussed. We also provide a brief introduction to Shannon‘s theoretic capacity concept and discuss simple coding methods used in wireless channels.12/2010: pages 9-46;