The optimal rate control problem in networks with unicast and multiratemulticast sessions is investigated. A penalty function approach is used to solve a convex programformulation of this problem, and then a heuristic...The optimal rate control problem in networks with unicast and multiratemulticast sessions is investigated. A penalty function approach is used to solve a convex programformulation of this problem, and then a heuristic rate control algorithm is derived. The algorithmis distributed, and suitable both for source-driven unicast sessions and receiver-driven multicastsessions. To obtain practical viability, the computational burden on core routers as well asend-hosts is kept very low, also is the overhead of network congestion feedback. Simulation resultsshow that the algorithm guarantees TCP (Transmission Control Protocol)-based unicast sessionscoexisting with multirate multicast sessions in a fair and friendly manner. It is also shown thatvarious fairness criteria of resource allocation could be achieved by choosing appropriate utilityfunctions, and resource-utilizing efficiencies would be likewise different.展开更多
Network coding is able to address output conflicts when fanout splitting is allowed for multicast switching.Hence,it successfully achieves a larger rate region than non-coding approaches in crossbar switches.However,n...Network coding is able to address output conflicts when fanout splitting is allowed for multicast switching.Hence,it successfully achieves a larger rate region than non-coding approaches in crossbar switches.However,network coding requires large coding buffers and a high computational cost on encoding and decoding.In this paper,we propose a novel Online Network Coding framework called Online NC for multicast switches,which is adaptive to constrained buffers.Moreover,it enjoys a much lower decoding complexity by a Vandermonde matrix based approach,as compared to conven-tional randomized network coding Our approach realizes online coding with one coding algo-rithm that synchronizes buffering and coding.Therefore,we significantly reduce requirements on buffer space,while also sustaining high throughputs.We confirm the superior advantages of our contributions using empirical studies.展开更多
A multicast replication algorithm is proposed for shared memory switches. It uses a dedicated FIFO to multicast by replicating cells at receiver and the FIFO is operating with shared memory in parallel. Speedup is use...A multicast replication algorithm is proposed for shared memory switches. It uses a dedicated FIFO to multicast by replicating cells at receiver and the FIFO is operating with shared memory in parallel. Speedup is used to promote loss and delay performance. A new queueing analytical model is developed based on a sub-timeslot approach. The system performance in terms of cell loss and delay is analyzed and verified by simulation.展开更多
The exponential growths of the World Wide Web (WWW) users have made the deployment of proxy servers popular on a network with limited resources. WWW clients perceive better response time, improved performance and spee...The exponential growths of the World Wide Web (WWW) users have made the deployment of proxy servers popular on a network with limited resources. WWW clients perceive better response time, improved performance and speed when response to requested pages are served from the cache of a proxy server, resulting in faster response times after the first document fetch. This work proposes cyclic multicast as a scalable technique for improving proxy server performance for next generation networks. The proposed system uses a cyclic multicast engine for the delivery of popular web pages from the proxy server cache to increasingly large users under limited server capacity and network resources. The cyclic multicast technique would be more efficient for the delivery of highly requested web pages from the cache to large number of receivers. We describe the operation of the cyclic multicast proxy server and characterized the gains in performance.展开更多
The Internet of thing(IoT)is a growing concept for smart cities,and it is compulsory to communicate data between different networks and devices.In the IoT,communication should be rapid with less delay and overhead.For...The Internet of thing(IoT)is a growing concept for smart cities,and it is compulsory to communicate data between different networks and devices.In the IoT,communication should be rapid with less delay and overhead.For this purpose,flooding is used for reliable data communication in a smart cities concept but at the cost of higher overhead,energy consumption and packet drop etc.This paper aims to increase the efficiency in term of overhead and reliability in term of delay by using multicasting and unicasting instead of flooding during packet forwarding in a smart city using the IoT concept.In this paper,multicasting and unicasting is used for IoT in smart cities within a receiver-initiated mesh-based topology to disseminate the data to the cluster head.Smart cities networks are divided into cluster head,and each cluster head or core node will be responsible for transferring data to the desired receiver.This protocol is a novel approach according to the best of our knowledge,and it proves to be very useful due to its efficiency and reliability in smart cities concept because IoT is a collection of devices and having a similar interest for transmission of data.The results are implemented in Network simulator 2(NS-2).The result shows that the proposed protocol shows performance in overhead,throughput,packet drop,delay and energy consumption as compared to benchmark schemes.展开更多
Along with the unbounded speedup and exponential growth of virtual queues requirement aiming for 100% throughput of multicast scheduling as the size of the high-speed switches scale, the issues of low throughput of mu...Along with the unbounded speedup and exponential growth of virtual queues requirement aiming for 100% throughput of multicast scheduling as the size of the high-speed switches scale, the issues of low throughput of multicast under non-speedup or fixed crosspoint buffer size is addressed. Inspired by the load balance two-stage Birkhoff-von Neumann architecture that can provide 100% throughput for all kinds of unicast traffic, a novel 3-stage architecture, consisting of the first stage for multicast fan-out splitting, the second stage for load balancing, and the last stage for switching (FSLBS) is proposed. And the dedicated multicast fan-out splitting to unicast (M2U) scheduling algorithm is developed for the first stage, while the scheduling algorithms in the last two stages adopt the periodic permutation matrix. FSLBS can achieve 100% throughput for integrated uni- and multicast traffic without speedup employing the dedicated M2U and periodic permutation matrix scheduling algorithm. The operation is theoretically validated adopting the fluid model.展开更多
A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR,multicast sessions are created and released only by source nodes. In each multicast session proces...A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR,multicast sessions are created and released only by source nodes. In each multicast session process,the source node keeps a list of intermediate nodes and destinations,which is encapsulated into the packet header when the source node sends a multicast packet. Nodes receiving multicast packets decide to accept or forward the packet according to the list. Depending on topology matrix maintained by unicast routing,the shortest virtual hierarchy routing tree is con-structed by improved Dijkstra algorithm. MIMR can achieve the minimum number of intermediate nodes,which are computed through the tree. No control packet is transmitted in the process of mul-ticast session. Load of the network is largely decreased. Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks.展开更多
MPLS(Multi-Protocol Label Switching) VPN(Virtual Private Network) traffic has been deployed widely, but currently only supports unicast. This paper briefly introduces several available MPLS VPN multicast approaches, a...MPLS(Multi-Protocol Label Switching) VPN(Virtual Private Network) traffic has been deployed widely, but currently only supports unicast. This paper briefly introduces several available MPLS VPN multicast approaches, and then analyzes their disadvantages. A novel mechanism that uses two-layer label stack to support MPLS VPN explicit multicast is proposed and the process is discussed in detail. The scalability and performance of the proposed mechanism are studied analytically. The result shows that our solution has great advantage over the currently available scheme in terms of saving core network bandwidth and improving the scalability.展开更多
文摘The optimal rate control problem in networks with unicast and multiratemulticast sessions is investigated. A penalty function approach is used to solve a convex programformulation of this problem, and then a heuristic rate control algorithm is derived. The algorithmis distributed, and suitable both for source-driven unicast sessions and receiver-driven multicastsessions. To obtain practical viability, the computational burden on core routers as well asend-hosts is kept very low, also is the overhead of network congestion feedback. Simulation resultsshow that the algorithm guarantees TCP (Transmission Control Protocol)-based unicast sessionscoexisting with multirate multicast sessions in a fair and friendly manner. It is also shown thatvarious fairness criteria of resource allocation could be achieved by choosing appropriate utilityfunctions, and resource-utilizing efficiencies would be likewise different.
基金Supported by the National 863 Projects of China(2009AA01Z205)the Fund of National Laboratory(P080010)+2 种基金the Natural Science Foundation of China(60872010,60972016)the Program for New Century Excellent Talents in University (NCET070339)the Funds for Distinguished Young Scientists of Hubei,China(2009 CDA150)
文摘Network coding is able to address output conflicts when fanout splitting is allowed for multicast switching.Hence,it successfully achieves a larger rate region than non-coding approaches in crossbar switches.However,network coding requires large coding buffers and a high computational cost on encoding and decoding.In this paper,we propose a novel Online Network Coding framework called Online NC for multicast switches,which is adaptive to constrained buffers.Moreover,it enjoys a much lower decoding complexity by a Vandermonde matrix based approach,as compared to conven-tional randomized network coding Our approach realizes online coding with one coding algo-rithm that synchronizes buffering and coding.Therefore,we significantly reduce requirements on buffer space,while also sustaining high throughputs.We confirm the superior advantages of our contributions using empirical studies.
文摘A multicast replication algorithm is proposed for shared memory switches. It uses a dedicated FIFO to multicast by replicating cells at receiver and the FIFO is operating with shared memory in parallel. Speedup is used to promote loss and delay performance. A new queueing analytical model is developed based on a sub-timeslot approach. The system performance in terms of cell loss and delay is analyzed and verified by simulation.
文摘The exponential growths of the World Wide Web (WWW) users have made the deployment of proxy servers popular on a network with limited resources. WWW clients perceive better response time, improved performance and speed when response to requested pages are served from the cache of a proxy server, resulting in faster response times after the first document fetch. This work proposes cyclic multicast as a scalable technique for improving proxy server performance for next generation networks. The proposed system uses a cyclic multicast engine for the delivery of popular web pages from the proxy server cache to increasingly large users under limited server capacity and network resources. The cyclic multicast technique would be more efficient for the delivery of highly requested web pages from the cache to large number of receivers. We describe the operation of the cyclic multicast proxy server and characterized the gains in performance.
文摘The Internet of thing(IoT)is a growing concept for smart cities,and it is compulsory to communicate data between different networks and devices.In the IoT,communication should be rapid with less delay and overhead.For this purpose,flooding is used for reliable data communication in a smart cities concept but at the cost of higher overhead,energy consumption and packet drop etc.This paper aims to increase the efficiency in term of overhead and reliability in term of delay by using multicasting and unicasting instead of flooding during packet forwarding in a smart city using the IoT concept.In this paper,multicasting and unicasting is used for IoT in smart cities within a receiver-initiated mesh-based topology to disseminate the data to the cluster head.Smart cities networks are divided into cluster head,and each cluster head or core node will be responsible for transferring data to the desired receiver.This protocol is a novel approach according to the best of our knowledge,and it proves to be very useful due to its efficiency and reliability in smart cities concept because IoT is a collection of devices and having a similar interest for transmission of data.The results are implemented in Network simulator 2(NS-2).The result shows that the proposed protocol shows performance in overhead,throughput,packet drop,delay and energy consumption as compared to benchmark schemes.
文摘Along with the unbounded speedup and exponential growth of virtual queues requirement aiming for 100% throughput of multicast scheduling as the size of the high-speed switches scale, the issues of low throughput of multicast under non-speedup or fixed crosspoint buffer size is addressed. Inspired by the load balance two-stage Birkhoff-von Neumann architecture that can provide 100% throughput for all kinds of unicast traffic, a novel 3-stage architecture, consisting of the first stage for multicast fan-out splitting, the second stage for load balancing, and the last stage for switching (FSLBS) is proposed. And the dedicated multicast fan-out splitting to unicast (M2U) scheduling algorithm is developed for the first stage, while the scheduling algorithms in the last two stages adopt the periodic permutation matrix. FSLBS can achieve 100% throughput for integrated uni- and multicast traffic without speedup employing the dedicated M2U and periodic permutation matrix scheduling algorithm. The operation is theoretically validated adopting the fluid model.
文摘A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR,multicast sessions are created and released only by source nodes. In each multicast session process,the source node keeps a list of intermediate nodes and destinations,which is encapsulated into the packet header when the source node sends a multicast packet. Nodes receiving multicast packets decide to accept or forward the packet according to the list. Depending on topology matrix maintained by unicast routing,the shortest virtual hierarchy routing tree is con-structed by improved Dijkstra algorithm. MIMR can achieve the minimum number of intermediate nodes,which are computed through the tree. No control packet is transmitted in the process of mul-ticast session. Load of the network is largely decreased. Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks.
基金Supported by the National Natural Science Foundation of China(No.90204003)and National"863"Project(2001AAl21052)
文摘MPLS(Multi-Protocol Label Switching) VPN(Virtual Private Network) traffic has been deployed widely, but currently only supports unicast. This paper briefly introduces several available MPLS VPN multicast approaches, and then analyzes their disadvantages. A novel mechanism that uses two-layer label stack to support MPLS VPN explicit multicast is proposed and the process is discussed in detail. The scalability and performance of the proposed mechanism are studied analytically. The result shows that our solution has great advantage over the currently available scheme in terms of saving core network bandwidth and improving the scalability.
