6 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
Satellite radio interface and radio resource management strategy for the delivery of multicast/broadcast services via an integrated satellite-terrestrial system
A variety of hybrid systems combining third-generation mobile communication networks with broadcast systems have been proposed for the delivery of multimedia broadcast multicast services (MBMS) to mobile users. The article discusses one of these alternatives, which involves the use of a geostationary satellite component for MBMS delivery. In particular, it proposes a radio access scheme for the satellite component of the system that features maximum commonalties with the standardized T-UMTS WCDMA-based interface. The ultimate advantage of this approach is more efficient delivery of MBMS as far as the mobile network operator is concerned. The required adaptations at the interface layers are described, and the radio resource management strategy that fulfills the particular requirements of the satellite system is presented. © 2004 IEEE
Recommended from our members
A Connection Admission Control Framework for UMTS based Satellite Systems.An Adaptive Admission Control algorithm with pre-emption control mechanism for unicast and multicast communications in satellite UMTS.
In recent years, there has been an exponential growth in the use of
multimedia applications. A satellite system offers great potential for
multimedia applications with its ability to broadcast and multicast a large
amount of data over a very large area as compared to a terrestrial system.
However, the limited transmission capacity along with the dynamically
varying channel conditions impedes the delivery of good quality multimedia
service in a satellite system which has resulted in research efforts for deriving
efficient radio resource management techniques. This issue is addressed in
this thesis, where the main emphasis is to design a CAC framework which
maximizes the utilization of the scarce radio resources available in the
satellite and at the same time increases the performance of the system for a
UMTS based satellite system supporting unicast and multicast traffic.
The design of the system architecture for a UMTS based satellite system is
presented. Based on this architecture, a CAC framework is designed
consisting of three different functionalities: the admission control procedure,
the retune procedure and the pre-emption procedure. The joint use of these
functionalities is proposed to allow the performance of the system to be
maintained under congestion. Different algorithms are proposed for different
functionalities; an adaptive admission control algorithm, a greedy retune
algorithm and three pre-emption algorithms (Greedy, SubSetSum, and
Fuzzy).
A MATLAB simulation model is developed to study the performance of the
proposed CAC framework. A GUI is created to provide the user with the
flexibility to configure the system settings before starting a simulation. The
configuration settings allow the system to be analysed under different
conditions.
The performance of the system is measured under different simulation
settings such as enabling and disabling of the two functionalities of the CAC
framework; retune procedure and the pre-emption procedure. The simulation
results indicate the CAC framework as a whole with all the functionalities
performs better than the other simulation settings
Recommended from our members
Radio Resource Management for Satellite UMTS. Dynamic scheduling algorithm for a UMTS-compatible satellite network.
The third generation of mobile communication systems introduce
interactive Multicast and Unicast multimedia services at a fast data rate of
up to 2 Mbps and is expected to complete the globalization of the mobile
telecommunication systems. The implementation of these services on
satellite systems, particularly for broadcast and multicast applications to
complement terrestrial services is ideal since satellite systems are capable
of providing global coverage in areas not served by terrestrial
telecommunication services. However, the main bottleneck of such
systems is the scarcity of radio resources for supporting multimedia
applications which has resulted in the rapid growth in research efforts for
deriving efficient radio resource management techniques. This issue is
addressed in this thesis, where the main emphasis is to design a dynamic
scheduling framework and algorithm that can improve the overall
performance of the radio resource management strategy of a UMTS
compatible satellite network, taking into account the unique characteristics
of wireless channel conditions.
This thesis will initially be focused on the design of the network and
functional architecture of a UMTS -compatible satellite network. Based on
this architecture, an effective scheduling framework is designed, which
can provide different types of resource assigning strategies. A functional
model of scheduler is defined to describe the behaviours and interactions
between different functional entities.
An OPNET simulation model with a complete network protocol stack is
developed to validate the performance of the scheduling algorithms
implemented in the satellite network. Different types of traffic are
considered for the OPNET simulation, such as the Poisson Process, ONOFF
Source and Self Similar Process, so that the performance of
scheduling algorithm can be analyzed for different types of services.
A novel scheduling algorithm is proposed to optimise the channel
utilisation by considering the characteristics of the wireless channel, which
are bursty and location dependent. In order to overcome the channel
errors, different code rates are applied for the user under different channel
conditions. The proposed scheduling algorithm is designed to give higher
priority to users with higher code rate, so that the throughput of network is
optimized and at the same time, maintaining the end users¿ service level
agreements. The fairness of the proposed scheduling algorithm is
validated using OPNET simulation. The simulation results show that the
algorithm can fairly allocate resource to different connections not only
among different service classes but also within the same service class
depending on their QoS attributes.Inmarsat Global Ltd. BGAN and the European Space Agency (ESA