In this paper, we investigate a call-admission and handoffcontrol framework for multi-tier cellular networks. We first propose and compare Call-Admission Control (CAC) algorithms based on the cell-dwelling time, by studying their impact on the handoff-call dropping and new-call blocking probabilities and the channel partitioning between the two tiers. Our results show that a simple, cell-dwelli...

In this work, we propose a Two-tier OverlayMulticast Architecture (TOMA) to provide scalable and efficient multicast support for a variety of group communication applications. In TOMA, Multicast Service Overlay Network (MSON) is advocated as the backbone service domain, while end users in the access domains form a number of small clusters, in which an application-layer multicast protocol is use...

Many natural superhydrophobic structures have hierarchical two-tier roughness which is empirically known to promote robust superhydrophobicity. We report the wetting and dewetting properties of two-tier roughness as a function of the wettability of the working fluid, where the surface tension of water/ethanol drops is tuned by the mixing ratio, and compare the results to one-tier roughness. Whe...

Driven by surging demands for high data rate services and better user experiences, there is an increasing capacity demand in heterogeneous cellular networks. As one of the promising solutions for capacity enhancement, densely deployed small cells are proposed to provide a huge capacity gain and improve the user experience with high data rate services. However, the inter-cell interference among ...

Faced with a high proportion of new energy power systems in the future, thermal units will become main peaking source, and reasonable recovery their capacity value focus attention. To plan supply structure while considering tariff support development low-carbon energy, this paper proposes two-tier planning model that coordinates scenery-to-fire ratio compensation mechanism for based on effectiv...

This study described an attempt to develop a networked two-tier test system. A two-tier test is a two-level multiple-choice question that diagnoses students’ alternative conceptions in science. Three networked, two-tier test items were presented in this study. Students in Taiwan (555 14 year olds and 599 16 year olds) were asked to answer these items online. An analysis of students’ answers sug...

Nowadays, Long Term Evolution (LTE) networks are becoming more and more popular. Femtocells have a strong potential for increasing the efficiency, cell coverage and network capacity of next-generation mobile networks. LTE femtocells represent a very promising answer to the ever growing bandwidth demand of mobile application. This system can be easily deployed without requiring a centralized pla...