20,454 research outputs found
Efficient Batch Update of Unique Identifiers in a Distributed Hash Table for Resources in a Mobile Host
Resources in a distributed system can be identified using identifiers based
on random numbers. When using a distributed hash table to resolve such
identifiers to network locations, the straightforward approach is to store the
network location directly in the hash table entry associated with an
identifier. When a mobile host contains a large number of resources, this
requires that all of the associated hash table entries must be updated when its
network address changes.
We propose an alternative approach where we store a host identifier in the
entry associated with a resource identifier and the actual network address of
the host in a separate host entry. This can drastically reduce the time
required for updating the distributed hash table when a mobile host changes its
network address. We also investigate under which circumstances our approach
should or should not be used. We evaluate and confirm the usefulness of our
approach with experiments run on top of OpenDHT.Comment: To be presented at the 2010 International Workshop on Cloud
Computing, Applications and Technologie
Resilient networking in wireless sensor networks
This report deals with security in wireless sensor networks (WSNs),
especially in network layer. Multiple secure routing protocols have been
proposed in the literature. However, they often use the cryptography to secure
routing functionalities. The cryptography alone is not enough to defend against
multiple attacks due to the node compromise. Therefore, we need more
algorithmic solutions. In this report, we focus on the behavior of routing
protocols to determine which properties make them more resilient to attacks.
Our aim is to find some answers to the following questions. Are there any
existing protocols, not designed initially for security, but which already
contain some inherently resilient properties against attacks under which some
portion of the network nodes is compromised? If yes, which specific behaviors
are making these protocols more resilient? We propose in this report an
overview of security strategies for WSNs in general, including existing attacks
and defensive measures. In this report we focus at the network layer in
particular, and an analysis of the behavior of four particular routing
protocols is provided to determine their inherent resiliency to insider
attacks. The protocols considered are: Dynamic Source Routing (DSR),
Gradient-Based Routing (GBR), Greedy Forwarding (GF) and Random Walk Routing
(RWR)
A Taxonomy of Self-configuring Service Discovery Systems
We analyze the fundamental concepts and issues in service
discovery. This analysis places service discovery in the context of distributed
systems by describing service discovery as a third generation
naming system. We also describe the essential architectures and the
functionalities in service discovery. We then proceed to show how service
discovery fits into a system, by characterizing operational aspects.
Subsequently, we describe how existing state of the art performs service
discovery, in relation to the operational aspects and functionalities, and
identify areas for improvement
User-Relative Names for Globally Connected Personal Devices
Nontechnical users who own increasingly ubiquitous network-enabled personal
devices such as laptops, digital cameras, and smart phones need a simple,
intuitive, and secure way to share information and services between their
devices. User Information Architecture, or UIA, is a novel naming and
peer-to-peer connectivity architecture addressing this need. Users assign UIA
names by "introducing" devices to each other on a common local-area network,
but these names remain securely bound to their target as devices migrate.
Multiple devices owned by the same user, once introduced, automatically merge
their namespaces to form a distributed "personal cluster" that the owner can
access or modify from any of his devices. Instead of requiring users to
allocate globally unique names from a central authority, UIA enables users to
assign their own "user-relative" names both to their own devices and to other
users. With UIA, for example, Alice can always access her iPod from any of her
own personal devices at any location via the name "ipod", and her friend Bob
can access her iPod via a relative name like "ipod.Alice".Comment: 7 pages, 1 figure, 1 tabl
A survey on subjecting electronic product code and non-ID objects to IP identification
Over the last decade, both research on the Internet of Things (IoT) and
real-world IoT applications have grown exponentially. The IoT provides us with
smarter cities, intelligent homes, and generally more comfortable lives.
However, the introduction of these devices has led to several new challenges
that must be addressed. One of the critical challenges facing interacting with
IoT devices is to address billions of devices (things) around the world,
including computers, tablets, smartphones, wearable devices, sensors, and
embedded computers, and so on. This article provides a survey on subjecting
Electronic Product Code and non-ID objects to IP identification for IoT
devices, including their advantages and disadvantages thereof. Different
metrics are here proposed and used for evaluating these methods. In particular,
the main methods are evaluated in terms of their: (i) computational overhead,
(ii) scalability, (iii) adaptability, (iv) implementation cost, and (v) whether
applicable to already ID-based objects and presented in tabular format.
Finally, the article proves that this field of research will still be ongoing,
but any new technique must favorably offer the mentioned five evaluative
parameters.Comment: 112 references, 8 figures, 6 tables, Journal of Engineering Reports,
Wiley, 2020 (Open Access
MAP: Medial Axis Based Geometric Routing in Sensor Networks
One of the challenging tasks in the deployment of dense wireless networks (like sensor networks) is in devising a routing scheme for node to node communication. Important consideration includes scalability, routing complexity, the length of the communication paths and the load sharing of the routes. In this paper, we show that a compact and expressive abstraction of network connectivity by the medial axis enables efficient and localized routing. We propose MAP, a Medial Axis based naming and routing Protocol that does not require locations, makes routing decisions locally, and achieves good load balancing. In its preprocessing phase, MAP constructs the medial axis of the sensor field, defined as the set of nodes with at least two closest boundary nodes. The medial axis of the network captures both the complex geometry and non-trivial topology of the sensor field. It can be represented compactly by a graph whose size is comparable with the complexity of the geometric features (e.g., the number of holes). Each node is then given a name related to its position with respect to the medial axis. The routing scheme is derived through local decisions based on the names of the source and destination nodes and guarantees delivery with reasonable and natural routes. We show by both theoretical analysis and simulations that our medial axis based geometric routing scheme is scalable, produces short routes, achieves excellent load balancing, and is very robust to variations in the network model
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