In wireless sensor networks(WSNs),nodes are often scheduled to alternate between working mode and sleeping mode from energy efficiency point of view.When delay is tolerable,it is not necessary to preserve network conn...In wireless sensor networks(WSNs),nodes are often scheduled to alternate between working mode and sleeping mode from energy efficiency point of view.When delay is tolerable,it is not necessary to preserve network connectivity during activity(working or sleeping) scheduling,enabling more sensors to be switched to sleeping mode and thus more energy savings.In this paper,the nodal behavior in such delay-tolerant WSNs(DT-WSNs) is modeled and analyzed.The maximum hop count with a routing path is derived in order not to violate a given sensor-to-sink delay constraint,along with extensive simulation results.展开更多
This paper presents an analytical model of a cross-layer communication system to enable improvement in the Transmission Control Protocol (TCP) over mixed wired and wireless Internet. The focus is on the quantitative p...This paper presents an analytical model of a cross-layer communication system to enable improvement in the Transmission Control Protocol (TCP) over mixed wired and wireless Internet. The focus is on the quantitative performance evaluation of the interactions between TCP NewReno and a hybrid Automatic Repeat reQuest protocol (HARQ) in the link layer (LL) with a finite buffer size. The significant improvement in TCP NewReno throughput when HARQ adaptively selects its optimal settings according to explicit cross-layer information is shown. Through ns-2 simulations, it is demonstrated that this proposed analytical model accurately predicts the TCP-HARQ system performance.展开更多
基金Sponsored by the Shanghai Education Bureau(Grant No. 11YZ93,A-3101-10-035)the Shanghai Baiyulan Funding(Grant No. 2010B086)the National Natural Science Foundation of China(Grant No. 61003215)
文摘In wireless sensor networks(WSNs),nodes are often scheduled to alternate between working mode and sleeping mode from energy efficiency point of view.When delay is tolerable,it is not necessary to preserve network connectivity during activity(working or sleeping) scheduling,enabling more sensors to be switched to sleeping mode and thus more energy savings.In this paper,the nodal behavior in such delay-tolerant WSNs(DT-WSNs) is modeled and analyzed.The maximum hop count with a routing path is derived in order not to violate a given sensor-to-sink delay constraint,along with extensive simulation results.
文摘This paper presents an analytical model of a cross-layer communication system to enable improvement in the Transmission Control Protocol (TCP) over mixed wired and wireless Internet. The focus is on the quantitative performance evaluation of the interactions between TCP NewReno and a hybrid Automatic Repeat reQuest protocol (HARQ) in the link layer (LL) with a finite buffer size. The significant improvement in TCP NewReno throughput when HARQ adaptively selects its optimal settings according to explicit cross-layer information is shown. Through ns-2 simulations, it is demonstrated that this proposed analytical model accurately predicts the TCP-HARQ system performance.
