5,179 research outputs found
Network Adaptive Interference Aware Routing Metric for Hybrid Wireless Mesh Networks
Wireless Mesh Networks provide a reliable, robust and resilient platform for broadband access. Main benefits of using Wireless Mesh Networks are their low cost, robustness, self healing, and self configuring properties. In Wireless Mesh Networks, routing metric determines the path from source to destination. Wireless link conditions can be affected by a number of factors including interference, congestion, mobility, and network topology. Routing metric needs to consider all these factors while making routing decisions. In addition, wireless link conditions do not remain static with time requiring the routing metric to be adaptive. Interference in Wireless Mesh Networks are of two types: inter-channel and intra-channel interference. Existing routing metrics for Wireless Mesh Networks either consider only one of the two interference types or do not capture changing network conditions. In this paper, we propose a new routing metric for Wireless Mesh Networks which takes into account both inter and intra-channel interference and is adaptive to changing network conditions. Our proposed metric is compared with the state of the art and shows throughput improvement of up to 20 percent and latency reduction of 25 percent
Early Experiences in Traffic Engineering Exploiting Path Diversity: A Practical Approach
Recent literature has proved that stable dynamic routing algorithms have
solid theoretical foundation that makes them suitable to be implemented in a
real protocol, and used in practice in many different operational network
contexts. Such algorithms inherit much of the properties of congestion
controllers implementing one of the possible combination of AQM/ECN schemes at
nodes and flow control at sources. In this paper we propose a linear program
formulation of the multi-commodity flow problem with congestion control, under
max-min fairness, comprising demands with or without exogenous peak rates. Our
evaluations of the gain, using path diversity, in scenarios as intra-domain
traffic engineering and wireless mesh networks encourages real implementations,
especially in presence of hot spots demands and non uniform traffic matrices.
We propose a flow aware perspective of the subject by using a natural
multi-path extension to current congestion controllers and show its performance
with respect to current proposals. Since flow aware architectures exploiting
path diversity are feasible, scalable, robust and nearly optimal in presence of
flows with exogenous peak rates, we claim that our solution rethinked in the
context of realistic traffic assumptions performs as better as an optimal
approach with all the additional benefits of the flow aware paradigm
A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks
In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs
Performance of TCP/UDP under Ad Hoc IEEE802.11
TCP is the De facto standard for connection oriented transport layer
protocol, while UDP is the De facto standard for transport layer protocol,
which is used with real time traffic for audio and video. Although there have
been many attempts to measure and analyze the performance of the TCP protocol
in wireless networks, very few research was done on the UDP or the interaction
between TCP and UDP traffic over the wireless link. In this paper, we tudy the
performance of TCP and UDP over IEEE802.11 ad hoc network. We used two
topologies, a string and a mesh topology. Our work indicates that IEEE802.11 as
a ad-hoc network is not very suitable for bulk transfer using TCP. It also
indicates that it is much better for real-time audio. Although one has to be
careful here since real-time audio does require much less bandwidth than the
wireless link bandwidth. Careful and detailed studies are needed to further
clarify that issue.Comment: 9 pages, 5 figures, ICT 2003 (10th International Conference on
Telecommunication
Recommended from our members
Multimedia delivery in the future internet
The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizens’ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications “on the move”, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
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