No abstract

No abstract

No abstract

Recent developments in low-cost CMOS cameras have created the opportunity of bringing imaging capabilities to sensor networks. Various visual sensor platforms have been developed with the aim of integrating visual data to wireless sensor applications. The objective of this article is to survey current visual sensor platforms according to in-network processing and compression/coding techniques together with their targeted applications. Characteristics of these platforms such as level of integration, data processing hardware, energy dissipation, radios and operating systems are also explored and discussed.

No abstract

Abstract-A fundamental problem in wireless networks is determining the broadcast capacity, i.e. the maximum data transfer rate from a given node to every other node in a relay network. This problem becomes more important as many network protocols rely on broadcast of certain control messages. In this paper, the scaling of the broadcast capacity with the number of nodes (N ) in the network is studied. In the highdensity regime (i.e. the node density goes to infinity; the network area is fixed), it is shown that the broadcast capacity is upper bounded by Θ(log N ). Schemes are provided that achieve i) Θ(log N ) throughput if the channel fading is spatially continuous; ii) Θ(log log N ) throughput if the channel fading is spatially i.i.d.. The reasons for this drastic reduction in throughput and the connections with multiuser diversity are discussed. Analogous results are provided for the extended-network model (i.e. the node density is fixed; the network area goes to infinity).

Unmanned aerial vehicles mounted base stations (UAV-BSs) are expected to become one of the significant components of the Next Generation Wireless Networks (NGWNs). Rapid deployment, mobility, higher chances of unobstructed propagation path, and flexibility features of UAV-BSs have attracted significant attention. Despite, potentially, high gains brought by UAV-BSs in NGWNs, many challenges are also introduced by them. Optimal location assignment to UAV-BSs, arguably, is the most widely investigated problem in the literature on UAV-BSs in NGWNs. This paper presents a comprehensive survey of the literature on the location optimization of UAV-BSs in NGWNs. A generic optimization framework through a universal Mixed Integer Non-Linear Programming (MINLP) formulation is constructed and the specifications of its constituents are elaborated. The generic problem is classified into a novel taxonomy. Due to the highly challenging nature of the optimization problem a range of solutions are adopted in the literature which are also covered under the aforementioned classification. Furthermore, future research directions on UAV-BS location optimization in 5G and beyond non-terrestrial aerial communication systems are discussed.

No abstract