Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content deliver...Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content delivery over the seamless global coverage area. However, the on-board supportable resources of a single satellite are extremely limited and lack of interaction with others. In this paper, we design a network model with two-layered cache deployment, i.e., satellite layer and ground base station layer, and two types of sharing links, i.e., terrestrial-satellite sharing(TSS) links and inter-satellite sharing(ISS) links, to enhance the capability of cooperative delivery over STINs. Thus, we use rateless codes for the content divided-packet transmission, and derive the total energy efficiency(EE) in the whole transmission procedure, which is defined as the ratio of traffic offloading and energy consumption. We formulate two optimization problems about maximizing EE in different sharing scenarios(only TSS and TSS-ISS),and propose two optimized algorithms to obtain the optimal content placement matrixes, respectively.Simulation results demonstrate that, enabling sharing links with optimized cache placement have more than 2 times improvement of EE performance than other traditional placement schemes. Particularly, TSS-ISS schemes have the higher EE performance than only TSS schemes under the conditions of enough number of satellites and smaller inter-satellite distances.展开更多
In conventional shared risk link group （SRLG）-diverse path selection （CSPS） algorithm in survivable GMPLS networks, SRLG is taken into account when selecting the backup paths, while the primary path selection meth...In conventional shared risk link group （SRLG）-diverse path selection （CSPS） algorithm in survivable GMPLS networks, SRLG is taken into account when selecting the backup paths, while the primary path selection method is the sarne as the algorithms without SRLG constraint. A problem of CSPS algorithm is that, after a primary path is selected, the success probability to select an SRLG-diverse backup path for it is low. If SRLG is taken into account when computing the primary path, then the probability to successfully select an SRLG-diverse backup path will be much increased. Based on this idea, an active SRLG-diverse path selection （ASPS） algorithm is proposed. To actively avoid selecting those SRLG links, when computing the primary path, a link that share risk with more links is assigned a larger link cost. To improve the resource utilization ratio, it is permitted that the bandwidth resources are shared among backup paths. What is more, differentiated reliability （DiR） requirements of different customers are considered in ASPS algorithm. The simulation results show that, compared with CSPS algorithm, ASPS algorithm not only increases successful protection probability but also improves resource utilization ratio.展开更多
Risk-disjoint routing is an efficient way to improve network survivability. In this article, a partial risk-disjoint routing algorithm based on link availability （PRDRA-LA） is proposed based on the complete risk-dis...Risk-disjoint routing is an efficient way to improve network survivability. In this article, a partial risk-disjoint routing algorithm based on link availability （PRDRA-LA） is proposed based on the complete risk-disjoint routing algorithm （CRDRA）. While calculating the protection path with PRDRA-LA, the links that share risks with the links in the working path are filtered by link availability. In addition, the risk disjoint degree between the protection path and the working path can be adjusted freely. Simulation results showed that when compared with CRDRA, routing connections with PRDRA-LA can achieve improved survivability while the number of connections that can be successfully routed over the current network is kept from serious decline.展开更多
基金supported by National Natural Sciences Foundation of China(No.62271165,62027802,61831008)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030297,2021A1515011572)Shenzhen Science and Technology Program ZDSYS20210623091808025,Stable Support Plan Program GXWD20231129102638002.
文摘Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content delivery over the seamless global coverage area. However, the on-board supportable resources of a single satellite are extremely limited and lack of interaction with others. In this paper, we design a network model with two-layered cache deployment, i.e., satellite layer and ground base station layer, and two types of sharing links, i.e., terrestrial-satellite sharing(TSS) links and inter-satellite sharing(ISS) links, to enhance the capability of cooperative delivery over STINs. Thus, we use rateless codes for the content divided-packet transmission, and derive the total energy efficiency(EE) in the whole transmission procedure, which is defined as the ratio of traffic offloading and energy consumption. We formulate two optimization problems about maximizing EE in different sharing scenarios(only TSS and TSS-ISS),and propose two optimized algorithms to obtain the optimal content placement matrixes, respectively.Simulation results demonstrate that, enabling sharing links with optimized cache placement have more than 2 times improvement of EE performance than other traditional placement schemes. Particularly, TSS-ISS schemes have the higher EE performance than only TSS schemes under the conditions of enough number of satellites and smaller inter-satellite distances.
基金supported by the National Natural Science Foundation of China (60673142)Applied Basic ResearchProject of Sichuan Province (2006J13-067).
文摘In conventional shared risk link group （SRLG）-diverse path selection （CSPS） algorithm in survivable GMPLS networks, SRLG is taken into account when selecting the backup paths, while the primary path selection method is the sarne as the algorithms without SRLG constraint. A problem of CSPS algorithm is that, after a primary path is selected, the success probability to select an SRLG-diverse backup path for it is low. If SRLG is taken into account when computing the primary path, then the probability to successfully select an SRLG-diverse backup path will be much increased. Based on this idea, an active SRLG-diverse path selection （ASPS） algorithm is proposed. To actively avoid selecting those SRLG links, when computing the primary path, a link that share risk with more links is assigned a larger link cost. To improve the resource utilization ratio, it is permitted that the bandwidth resources are shared among backup paths. What is more, differentiated reliability （DiR） requirements of different customers are considered in ASPS algorithm. The simulation results show that, compared with CSPS algorithm, ASPS algorithm not only increases successful protection probability but also improves resource utilization ratio.
基金This work is supported by the National Science Fund for Distinguished Young Scholars（60325104）；the National Natural Science Foundation of China （60572021）；the Hi-Tech Research and Development Program of China （2006AA01Z243）；the PCSIRT Project of M0E （IRT0609）；the International Cooperation Project of M0ST （2006DFA 11040）.
文摘Risk-disjoint routing is an efficient way to improve network survivability. In this article, a partial risk-disjoint routing algorithm based on link availability （PRDRA-LA） is proposed based on the complete risk-disjoint routing algorithm （CRDRA）. While calculating the protection path with PRDRA-LA, the links that share risks with the links in the working path are filtered by link availability. In addition, the risk disjoint degree between the protection path and the working path can be adjusted freely. Simulation results showed that when compared with CRDRA, routing connections with PRDRA-LA can achieve improved survivability while the number of connections that can be successfully routed over the current network is kept from serious decline.
