91 research outputs found
The Effect of Voice Packet Size on End-To-End delay in 802.11b Networks
Voice over IP (VoIP) uses the existing data networks to support voice services. It has a broad appeal in that it is currently unregulated and calls can be placed free of cost to any part of the globe. The integration of voice traffic with data traffic opens up opportunities for new revenue stream for Internet Service Providers. However, in mixing data types the constraints on each data type must still be met and unlike regular data, voice networks are chiefly limited by end-to-end delay. In the case of packet switched networks delay becomes a determining factor in the quality of the voice call and therefore the success of VoIP. At the same time, WLANs are becoming widely adopted due to the simplicity in installation and convenience offered. Advancement in technology now enables WLANs to provide most of the facilities provided by their wired counterparts with the added benefit of mobility at a very low cost. The benefits of combining IP telephony and WLANs can be effectively utilized if the control over end-to-end delay can be achieved. In conventional IP telephony the voice packets travel across the wired Internet. We developed a study in which the final hop on each end of the communication channel is a wireless 802.11b network. Results show that with a wireless network at the transmitting end the delay characteristics change considerably
Weighted Round Robin Configuration for Worst-Case Delay Optimization in Network-on-Chip
We propose an approach for computing the end-to-end delay bound of individual variable bit-rate flows in a FIFO multiplexer with aggregate scheduling under Weighted Round Robin (WRR) policy. To this end, we use network calculus to derive per-flow end-to-end equivalent service curves employed for computing Least Upper Delay Bounds (LUDBs) of individual flows. Since real time applications are going to meet guaranteed services with lower delay bounds, we optimize weights in WRR policy to minimize LUDBs while satisfying performance constraints. We formulate two constrained delay optimization problems, namely, Minimize-Delay and Multiobjective optimization. Multi-objective optimization has both total delay bounds and their variance as minimization objectives. The proposed optimizations are solved using a genetic algorithm. A Video Object Plane Decoder (VOPD) case study exhibits 15.4% reduction of total worst-case delays and 40.3% reduction on the variance of delays when compared with round robin policy. The optimization algorithm has low run-time complexity, enabling quick exploration of large design spaces. We conclude that an appropriate weight allocation can be a valuable instrument for delay optimization in on-chip network designs
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
Design of a transport coding scheme for high-quality video over ATM networks
Caption title.Includes bibliographical references (p. 38-39).Supported by ARPA. F30602-92-C-0030 Supported by the Laboratory for Information and Decision Systems, Massachusetts Institute of Technology. DAAH04-95-1-0103V. Parthasarathy, J.W. Modestino and K.S. Vastola
pDCell: an End-to-End Transport Protocol for Mobile Edge Computing Architectures
Pendiente publicación 2019To deal with increasingly demanding services and the rapid growth
in number of devices and traffic, 5G and beyond mobile networks
need to provide extreme capacity and peak data rates at very low
latencies. Consequently, applications and services need to move
closer to the users into so-called edge data centers. At the same
time, there is a trend to virtualize core and radio access network
functionalities and bring them to edge data centers as well. However,
as is known from conventional data centers, legacy transport
protocols such as TCP are vastly suboptimal in such a setting.
In this work, we present pDCell, a transport design for mobile
edge computing architectures that extends data center transport
approaches to the mobile network domain. Specifically, pDCell
ensures that data traffic from application servers arrives at virtual
radio functions (i.e., C-RAN Central Units) timely to (i) minimize
queuing delays and (ii) to maximize cellular network utilization.
We show that pDCell significantly improves flow completion times
compared to conventional transport protocols like TCP and data
center transport solutions, and is thus an essential component for
future mobile networks.This work is partially supported by the European Research Council
grant ERC CoG 617721, the Ramon y Cajal grant from the Spanish
Ministry of Economy and Competitiveness RYC-2012-10788, by
the European Union H2020-ICT grant 644399 (MONROE), by the
H2020 collaborative Europe/Taiwan research project 5G-CORAL
(grant num. 761586) and the Madrid Regional Government through
the TIGRE5-CM program (S2013/ICE-2919). Further, the work of
Dr. Kogan is partially supported by a grant from the Cisco University
Research Program Fund, an advised fund of Silicon Valley
Community Foundation.No publicad
A Survey on Semantic Communications for Intelligent Wireless Networks
With deployment of 6G technology, it is envisioned that competitive edge of
wireless networks will be sustained and next decade's communication
requirements will be stratified. Also 6G will aim to aid development of a human
society which is ubiquitous and mobile, simultaneously providing solutions to
key challenges such as, coverage, capacity, etc. In addition, 6G will focus on
providing intelligent use-cases and applications using higher data-rates over
mill-meter waves and Tera-Hertz frequency. However, at higher frequencies
multiple non-desired phenomena such as atmospheric absorption, blocking, etc.,
occur which create a bottleneck owing to resource (spectrum and energy)
scarcity. Hence, following same trend of making efforts towards reproducing at
receiver, exact information which was sent by transmitter, will result in a
never ending need for higher bandwidth. A possible solution to such a challenge
lies in semantic communications which focuses on meaning (context) of received
data as opposed to only reproducing correct transmitted data. This in turn will
require less bandwidth, and will reduce bottleneck due to various undesired
phenomenon. In this respect, current article presents a detailed survey on
recent technological trends in regard to semantic communications for
intelligent wireless networks. We focus on semantic communications architecture
including model, and source and channel coding. Next, we detail cross-layer
interaction, and various goal-oriented communication applications. We also
present overall semantic communications trends in detail, and identify
challenges which need timely solutions before practical implementation of
semantic communications within 6G wireless technology. Our survey article is an
attempt to significantly contribute towards initiating future research
directions in area of semantic communications for intelligent 6G wireless
networks
A Scalable and Adaptive Network on Chip for Many-Core Architectures
In this work, a scalable network on chip (NoC) for future many-core architectures is proposed and investigated. It supports different QoS mechanisms to ensure predictable communication. Self-optimization is introduced to adapt the energy footprint and the performance of the network to the communication requirements. A fault tolerance concept allows to deal with permanent errors. Moreover, a template-based automated evaluation and design methodology and a synthesis flow for NoCs is introduced
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