tailieunhanh - Resource Management in Satellite Networks part 10

Resource Management in Satellite Networks part 10. This book provides significant knowledge on innovative radio resource management schemes for satellite communication systems that exploit lower layer adaptivity and the knowledge of layer 3 IP QoS support and transport layer behavior. The book integrates competencies considering all the parts of system design: propagation aspects, radio resource management, access protocols, network protocols, transport layer protocols, and more, to cover both broadband and mobile satellite systems | 70 José Ignacio Moreno Novella Francisco Javier Gonzalez Castaño The traffic classes established by BSM are based on ITU-T Tiphon 3GPP and UMTS decisions with adaptation to the satellite environment. In particular the BSM standards deal with variable link layer conditions high asymmetry and higher delay that are characteristics of satellite networks. The aim is to enable the satellite network and the Internet Service Provider ISP to ensure acceptable QoS levels and to relate these issues to the BSM architecture for broadband systems. In UMTS and by extension in satellite networks four basic service classes layer 7 are defined 4 conversational streaming interactive and background. It is interesting to note that there is no strict one-to-one mapping between these service classes and the namesake traffic classes layer 2 6 an interactive application can very well use a bearer of the conversational traffic class if the application service or the user has tight requirements on delay. In the following sub-Sections the performance requirements for all four service classes are investigated from the user perspective. Note that the delay values in the Tables of the following sub-Sections represent one-way delay . from originating entity to terminating entity . Performance requirements for conversational services The most common service in this category is real-time conversation such as telephony speech. Voice over IP VoIP and video conferencing also belong to this category with increasing relevance as the Internet is rapidly evolving. This is the only class whose characteristics are strictly determined by human perception senses . Thus this scheme has the most stringent QoS requirements the transfer time should be low and at the same time the temporal relation of information entities of the stream should be preserved. The limit for acceptable transfer delay is very strict failure to provide low transfer delays will result in unacceptable lack of quality . However .