46,192 research outputs found
Distributed Storage in Mobile Wireless Networks with Device-to-Device Communication
We consider the use of distributed storage (DS) to reduce the communication
cost of content delivery in wireless networks. Content is stored (cached) in a
number of mobile devices using an erasure correcting code. Users retrieve
content from other devices using device-to-device communication or from the
base station (BS), at the expense of higher communication cost. We address the
repair problem when a device storing data leaves the cell. We introduce a
repair scheduling where repair is performed periodically and derive analytical
expressions for the overall communication cost of content download and data
repair as a function of the repair interval. The derived expressions are then
used to evaluate the communication cost entailed by DS using several erasure
correcting codes. Our results show that DS can reduce the communication cost
with respect to the case where content is downloaded only from the BS, provided
that repairs are performed frequently enough. If devices storing content arrive
to the cell, the communication cost using DS is further reduced and, for large
enough arrival rate, it is always beneficial. Interestingly, we show that MDS
codes, which do not perform well for classical DS, can yield a low overall
communication cost in wireless DS.Comment: After final editing for publication in TCO
Smart PIN: utility-based replication and delivery of multimedia content to mobile users in wireless networks
Next generation wireless networks rely on heterogeneous connectivity technologies to support various rich media services such as personal information storage, file sharing and multimedia streaming. Due to users’ mobility and dynamic characteristics of wireless networks, data availability in collaborating devices is a critical issue. In this context Smart PIN was proposed as a personal information network which focuses on performance of delivery and cost efficiency. Smart PIN uses a novel data replication scheme based on individual and overall system utility to best balance the requirements for static data and multimedia content delivery with variable device availability due to user mobility. Simulations show improved results in comparison with other general purpose data replication schemes in terms of data availability
Service and device discovery of nodes in a wireless sensor network
Emerging wireless communication standards and more capable sensors and actuators have pushed further development of wireless sensor networks. Deploying a large number of sensor\ud
nodes requires a high-level framework enabling the devices to present themselves and the resources they hold. The device and the resources can be described as services, and in this paper, we review a number of well-known service discovery protocols. Bonjour stands out with its auto-configuration, distributed architecture, and sharing of resources. We also present a lightweight implementation in order to demonstrate that an emerging standards-based device and service discovery protocol can actually be deployed on small wireless sensor nodes
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