4,720 research outputs found
Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges
With the rapid development of marine activities, there has been an increasing
number of maritime mobile terminals, as well as a growing demand for high-speed
and ultra-reliable maritime communications to keep them connected.
Traditionally, the maritime Internet of Things (IoT) is enabled by maritime
satellites. However, satellites are seriously restricted by their high latency
and relatively low data rate. As an alternative, shore & island-based base
stations (BSs) can be built to extend the coverage of terrestrial networks
using fourth-generation (4G), fifth-generation (5G), and beyond 5G services.
Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs.
Despite of all these approaches, there are still open issues for an efficient
maritime communication network (MCN). For example, due to the complicated
electromagnetic propagation environment, the limited geometrically available BS
sites, and rigorous service demands from mission-critical applications,
conventional communication and networking theories and methods should be
tailored for maritime scenarios. Towards this end, we provide a survey on the
demand for maritime communications, the state-of-the-art MCNs, and key
technologies for enhancing transmission efficiency, extending network coverage,
and provisioning maritime-specific services. Future challenges in developing an
environment-aware, service-driven, and integrated satellite-air-ground MCN to
be smart enough to utilize external auxiliary information, e.g., sea state and
atmosphere conditions, are also discussed
Maximum Multipath Routing Throughput in Multirate Wireless Mesh Networks
In this paper, we consider the problem of finding the maximum routing
throughput between any pair of nodes in an arbitrary multirate wireless mesh
network (WMN) using multiple paths. Multipath routing is an efficient technique
to maximize routing throughput in WMN, however maximizing multipath routing
throughput is a NP-complete problem due to the shared medium for
electromagnetic wave transmission in wireless channel, inducing collision-free
scheduling as part of the optimization problem. In this work, we first provide
problem formulation that incorporates collision-free schedule, and then based
on this formulation we design an algorithm with search pruning that jointly
optimizes paths and transmission schedule. Though suboptimal, compared to the
known optimal single path flow, we demonstrate that an efficient multipath
routing scheme can increase the routing throughput by up to 100% for simple
WMNs.Comment: This paper has been accepted for publication in IEEE 80th Vehicular
Technology Conference, VTC-Fall 201
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