8,456 research outputs found
Analysis domain model for shared virtual environments
The field of shared virtual environments, which also
encompasses online games and social 3D environments, has a
system landscape consisting of multiple solutions that share great functional overlap. However, there is little system interoperability between the different solutions. A shared virtual environment has an associated problem domain that is highly complex raising difficult challenges to the development process, starting with the architectural design of the underlying system. This paper has two main contributions. The first contribution is a broad domain analysis of shared virtual environments, which enables developers to have a better understanding of the whole rather than the part(s). The second contribution is a reference domain model for discussing and describing solutions - the Analysis Domain Model
CoAP over ICN
The Constrained Application Protocol (CoAP) is a specialized Web transfer
protocol for resource-oriented applications intended to run on constrained
devices, typically part of the Internet of Things. In this paper we leverage
Information-Centric Networking (ICN), deployed within the domain of a network
provider that interconnects, in addition to other terminals, CoAP endpoints in
order to provide enhanced CoAP services. We present various CoAP-specific
communication scenarios and discuss how ICN can provide benefits to both
network providers and CoAP applications, even though the latter are not aware
of the existence of ICN. In particular, the use of ICN results in smaller state
management complexity at CoAP endpoints, simpler implementation at CoAP
endpoints, and less communication overhead in the network.Comment: Proc. of the 8th IFIP International Conference on New Technologies,
Mobility and Security (NTMS), Larnaca, Cyprus, November, 201
Software Defined Networks based Smart Grid Communication: A Comprehensive Survey
The current power grid is no longer a feasible solution due to
ever-increasing user demand of electricity, old infrastructure, and reliability
issues and thus require transformation to a better grid a.k.a., smart grid
(SG). The key features that distinguish SG from the conventional electrical
power grid are its capability to perform two-way communication, demand side
management, and real time pricing. Despite all these advantages that SG will
bring, there are certain issues which are specific to SG communication system.
For instance, network management of current SG systems is complex, time
consuming, and done manually. Moreover, SG communication (SGC) system is built
on different vendor specific devices and protocols. Therefore, the current SG
systems are not protocol independent, thus leading to interoperability issue.
Software defined network (SDN) has been proposed to monitor and manage the
communication networks globally. This article serves as a comprehensive survey
on SDN-based SGC. In this article, we first discuss taxonomy of advantages of
SDNbased SGC.We then discuss SDN-based SGC architectures, along with case
studies. Our article provides an in-depth discussion on routing schemes for
SDN-based SGC. We also provide detailed survey of security and privacy schemes
applied to SDN-based SGC. We furthermore present challenges, open issues, and
future research directions related to SDN-based SGC.Comment: Accepte
MENU: multicast emulation using netlets and unicast
High-end networking applications such as Internet TV and software distribution have generated a demand for multicast protocols as an integral part of the network. This will allow such applications to support data dissemination to large groups of users in a scalable and reliable manner. Existing IP multicast protocols lack these features and also require state storage in the core of the network which is costly to implement. In this paper, we present a new multicast protocol referred to as MENU. It realises a scalable and a reliable multicast protocol model by pushing the tree building complexity to the edges of the network, thereby eliminating processing and state storage in the core of the network. The MENU protocol builds multicast support in the network using mobile agent based active network services, Netlets, and unicast addresses. The multicast delivery tree in MENU is a two level hierarchical structure where users are partitioned into client communities based on geographical proximity. Each client community in the network is treated as a single virtual destination for traffic from the server. Netlet based services referred to as hot spot delegates (HSDs) are deployed by servers at "hot spots" close to each client community. They function as virtual traffic destinations for the traffic from the server and also act as virtual source nodes for all users in the community. The source node feeds data to these distributed HSDs which in turn forward data to all downstream users through a locally constructed traffic delivery tree. It is shown through simulations that the resulting system provides an efficient means to incrementally build a source customisable secured multicast protocol which is both scalable and reliable. Furthermore, results show that MENU employs minimal processing and reduced state information in networks when compared to existing IP multicast protocols
Efficient Micro-Mobility using Intra-domain Multicast-based Mechanisms (M&M)
One of the most important metrics in the design of IP mobility protocols is
the handover performance. The current Mobile IP (MIP) standard has been shown
to exhibit poor handover performance. Most other work attempts to modify MIP to
slightly improve its efficiency, while others propose complex techniques to
replace MIP. Rather than taking these approaches, we instead propose a new
architecture for providing efficient and smooth handover, while being able to
co-exist and inter-operate with other technologies. Specifically, we propose an
intra-domain multicast-based mobility architecture, where a visiting mobile is
assigned a multicast address to use while moving within a domain. Efficient
handover is achieved using standard multicast join/prune mechanisms. Two
approaches are proposed and contrasted. The first introduces the concept
proxy-based mobility, while the other uses algorithmic mapping to obtain the
multicast address of visiting mobiles. We show that the algorithmic mapping
approach has several advantages over the proxy approach, and provide mechanisms
to support it. Network simulation (using NS-2) is used to evaluate our scheme
and compare it to other routing-based micro-mobility schemes - CIP and HAWAII.
The proactive handover results show that both M&M and CIP shows low handoff
delay and packet reordering depth as compared to HAWAII. The reason for M&M's
comparable performance with CIP is that both use bi-cast in proactive handover.
The M&M, however, handles multiple border routers in a domain, where CIP fails.
We also provide a handover algorithm leveraging the proactive path setup
capability of M&M, which is expected to outperform CIP in case of reactive
handover.Comment: 12 pages, 11 figure
Feasibility Study of Enabling V2X Communications by LTE-Uu Radio Interface
Compared with the legacy wireless networks, the next generation of wireless
network targets at different services with divergent QoS requirements, ranging
from bandwidth consuming video service to moderate and low date rate machine
type services, and supporting as well as strict latency requirements. One
emerging new service is to exploit wireless network to improve the efficiency
of vehicular traffic and public safety. However, the stringent packet
end-to-end (E2E) latency and ultra-low transmission failure rates pose
challenging requirements on the legacy networks. In other words, the next
generation wireless network needs to support ultra-reliable low latency
communications (URLLC) involving new key performance indicators (KPIs) rather
than the conventional metric, such as cell throughput in the legacy systems. In
this paper, a feasibility study on applying today's LTE network infrastructure
and LTE-Uu air interface to provide the URLLC type of services is performed,
where the communication takes place between two traffic participants (e.g.,
vehicle-to-vehicle and vehicle-to-pedestrian). To carry out this study, an
evaluation methodology of the cellular vehicle-to-anything (V2X) communication
is proposed, where packet E2E latency and successful transmission rate are
considered as the key performance indicators (KPIs). Then, we describe the
simulation assumptions for the evaluation. Based on them, simulation results
are depicted that demonstrate the performance of the LTE network in fulfilling
new URLLC requirements. Moreover, sensitivity analysis is also conducted
regarding how to further improve system performance, in order to enable new
emerging URLLC services.Comment: Accepted by IEEE/CIC ICCC 201
Issues in providing a reliable multicast facility
Issues involved in point-to-multipoint communication are presented and the literature for proposed solutions and approaches surveyed. Particular attention is focused on the ideas and implementations that align with the requirements of the environment of interest. The attributes of multicast receiver groups that might lead to useful classifications, what the functionality of a management scheme should be, and how the group management module can be implemented are examined. The services that multicasting facilities can offer are presented, followed by mechanisms within the communications protocol that implements these services. The metrics of interest when evaluating a reliable multicast facility are identified and applied to four transport layer protocols that incorporate reliable multicast
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