50,801 research outputs found
Will SDN be part of 5G?
For many, this is no longer a valid question and the case is considered
settled with SDN/NFV (Software Defined Networking/Network Function
Virtualization) providing the inevitable innovation enablers solving many
outstanding management issues regarding 5G. However, given the monumental task
of softwarization of radio access network (RAN) while 5G is just around the
corner and some companies have started unveiling their 5G equipment already,
the concern is very realistic that we may only see some point solutions
involving SDN technology instead of a fully SDN-enabled RAN. This survey paper
identifies all important obstacles in the way and looks at the state of the art
of the relevant solutions. This survey is different from the previous surveys
on SDN-based RAN as it focuses on the salient problems and discusses solutions
proposed within and outside SDN literature. Our main focus is on fronthaul,
backward compatibility, supposedly disruptive nature of SDN deployment,
business cases and monetization of SDN related upgrades, latency of general
purpose processors (GPP), and additional security vulnerabilities,
softwarization brings along to the RAN. We have also provided a summary of the
architectural developments in SDN-based RAN landscape as not all work can be
covered under the focused issues. This paper provides a comprehensive survey on
the state of the art of SDN-based RAN and clearly points out the gaps in the
technology.Comment: 33 pages, 10 figure
Mobility: a double-edged sword for HSPA networks
This paper presents an empirical study on the performance of mobile High Speed Packet Access (HSPA, a 3.5G cellular standard) networks in Hong Kong via extensive field tests. Our study, from the viewpoint of end users, covers virtually all possible mobile scenarios in urban areas, including subways, trains, off-shore ferries and city buses. We have confirmed that mobility has largely negative impacts on the performance of HSPA networks, as fast-changing wireless environment causes serious service deterioration or even interruption. Meanwhile our field experiment results have shown unexpected new findings and thereby exposed new features of the mobile HSPA networks, which contradict commonly held views. We surprisingly find out that mobility can improve fairness of bandwidth sharing among users and traffic flows. Also the triggering and final results of handoffs in mobile HSPA networks are unpredictable and often inappropriate, thus calling for fast reacting fallover mechanisms. We have conducted in-depth research to furnish detailed analysis and explanations to what we have observed. We conclude that mobility is a double-edged sword for HSPA networks. To the best of our knowledge, this is the first public report on a large scale empirical study on the performance of commercial mobile HSPA networks
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Controlling the handover mechanism in wireless mobile nodes using game theory
This paper proposes a novel network selection mechanism as an extension
to the FMIPv6 [2] protocol, which improves handover latency in the MIPv6 [1] in
the case where the Mobile Nodes (MN) have a single wireless interface with multiple
Care-of-Addresses (CoAâs). Moreover, this paper proposes a novel interface/network
selection mechanism, which is an extension to the MFMIPv6 [5], which work when
the mobile node has more than one wireless interface. Generally, the previous access
router (PAR) in the FMIPv6 protocol forwards all the arrived packets to the new
access router (NAR) by setting up a tunnel to it in order to prevent packet losses
incurred by latency during handover procedure. However, there is no protocol which
offers the user and/or the application to dynamically choose the right NAR (i.e. the
one offers a better service). Whatâs more, one of the main objectives of the next
generation networks will be heterogeneity in the wireless access environment in
which a mobile terminal will be able to connect to multiple radio networks
simultaneously. For these reasons, network selection and efficient load balancing
mechanisms among different networks will be required to achieve high-speed
connectivity with seamless mobility. To this end; Game Theory [3], naturally
becomes a useful and powerful tool to research this kind of problems. Game theory
is a mathematical tool developed to understand competitive situations in which
rational decision makers interact to achieve their objectives. The mechanism
improves the handover latency, the user ability to choose the right interface/network
and controls when to force the MN to make the handover
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