This article describes a global QoS architecture for multimedia traffic in mobile heterogeneous environments. This architecture supports both multiple access networks and multiple service provider scenarios. The architecture is able to provide QoS per user and per service, implementing the notion of a user profile associated with control element functions. An integrated management approach to service and network management in the case of heterogeneous and mobile network access is presented based on cooperative association between QoS brokers and authentication, authorization, accounting, and charging systems. The overall exchange of messages is exemplified for the case of a field test with specific optimizations for voice traffic.
Mobile network operators are experiencing a tremendous increase in data traffic due to the growing popularity of bandwidth-intensive video services. This challenge can be faced either by boosting the capacity of the network infrastructure, or by means of offloading traffic from the backhaul and core network and serving contents from distributed cache servers close to the users. Network operators can extend the coverage of traditional CDNs by making usage of caching locations much closer to the users than traditional CDNs. Additionally, network operators can optimize the caching and delivery of contents by exploiting the complete knowledge of their network for designing a cost-effective infrastructure able to achieve both improved user satisfaction and cost savings. This article provides thoroughly justified design principles for a highly distributed operator-owned CDN while focusing on four key aspects: the optimal location of cache servers, mechanisms for request routing, content replica placement, and content outsourcing and retrieval
SUMMARYThe EU IST project Moby Dick worked with the vision, shared by many other researchers, that Next Generation Networks will be based on IPv6 with mobility, security and quality of service (QoS) support. These networks will offer all kinds of services, including multimedia ones with real-time requirements, traditionally offered by circuit switched technologies. The IETF has finished the standardization of a solution for mobility in IPv6 networks: Mobile IPv6 (MIPv6). Additional protocols are being discussed to improve the performance of Mobile IPv6 to support real-time traffic during handovers; one of these proposals is Fast Handovers for MIPv6. This paper analyzes experimentally-using real implementations for Linux O.S.-the performance of MIPv6 and Fast Handovers for MIPv6, to study if the performance is acceptable for multimedia applications. Both quantitative measurements and results of quality perceived by users of IPv6 multimedia applications are provided, showing that Fast Handovers for MIPv6 approach is good enough even for multimedia applications with strict real-time requirements.
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