In this paper, we study the problem of processing continuous range queries in a hierarchical wireless sensor network. Recently, as the size of sensor networks increases due to the growth of ubiquitous computing environments and wireless networks, building wireless sensor networks in a hierarchical configuration is put forth as a practical approach. Contrasted with the traditional approach of bu...

HAS Network Medium I Abstract A three-tier gateway architecture for internetworking between home automation networks and a TCPlIP based wide area network, such as the internet, is described. The architecture abstracts the functionality of any home network into a driver layer (tier one), and provides a common access layer (tier two) from any TCP/IP network application (tier three) to a local hom...

To satisfy both the bandwidth efficiency of low-speed mobile hosts (MHs) and seamless handoff of high-speed MHs in cellular networks, this paper proposes a reservation scheme which exploits a dynamic two-tier cell structure and the handoff probability. The dynamic two-tier cell structure determines the reservation and non-reservation zones according to the speed of MHs. The handoff probability ...

This paper addresses how to improve the energy efficiency of two-tier OFDMA femtocell networks using power control. Firstly, the energy efficiencies of two typical power control methods are analyzed, including fixed power setting (FPS) and minimum power consumption (MPC) methods. Then a distributed maximum energy efficiency (MEE) method is proposed. Each macrocell and femtocell dynamically adju...

In this paper, we develop a green handover protocol in two-tier OFDMA macrocell-femtocell networks. To improve the energy efficiency of femtocell base station, the proposed green handover protocol can intelligently switch on its radio communication and associated processing, or called as “wake up” from the idle mode, if the remainder data of a mobile host can be completely uploaded through the ...

Two-tier cellular networks consist of a group of contiguous microcells overlaid by a macrocell. This design provides an enhanced use of the networks’ resources for both high and low speed users because of the availability of additional channels. However, this causes an increase in the number of handoffs between cells due to having smaller cell sizes in the microcell tier. Since, handoff call bl...

With the exponential increase in mobile internet traffic, future cellular networks face great challenges to satisfy the demand of network capacity. At the same time, high data rate transmission and rapid increasing number of users also seriously burden the power consumption and the cost of cellular networks. Base station (BS) is the main part of power consumption, so reducing energy consumption...

Integration of cellular networks and Wireless local area networks (WLANs) will be very useful for development of fourth generation communication technologies. The integration of two or more networks would be done by employing techniques of vertical handoff across different radio access networks. Internetworking system can offer users with ubiquitous connectivity as well as high-speed data acces...

In this paper we demonstrate the rate gains achieved by two-tier heterogeneous cellular networks (HetNets) with varying degrees of coordination between macrocell and microcell base stations (BSs). We show that without the presence of coordination, network densification does not provide any gain in the sum rate and rapidly decreases the mean per-user signalto-interference-plus-noise-ratio (SINR)...