The Transmission Control Protocol.

Next generation fixed wireless broadband networks are being increasingly deployed as mesh networks in order to provide and extend access to the internet. These networks are characterized by the use of multiple orthogonal channels and nodes with the ability to simultaneously communicate with many neighbors using multiple radios (interfaces) over orthogonal channels. Networks based on the IEEE 802.11a/b/g and 802.16 standards are examples of these systems. However, due to the limited number of available orthogonal channels, interference is still a factor in such networks. In this paper, we propose a network model that captures the key practical aspects of such systems and characterize the constraints binding their behavior. We provide necessary conditions to verify the feasibility of rate vectors in these networks, and use them to derive upper bounds on the capacity in terms of achievable throughput, using a fast primal-dual algorithm. We then develop two link channel assignment schemes, one static and the other dynamic, in order to derive lower bounds on the achievable throughput. We demonstrate through simulations that the dynamic link channel assignment scheme performs close to optimal on the average, while the static link channel assignment algorithm also performs very well. The methods proposed in this paper can be a valuable tool for network designers in planning network deployment and for optimizing different performance objectives.

Characterizing the capacity region in multi-radio multi-channel wireless mesh networks

In this article we provide a comprehensive review of the existing literature on techniques and protocols for in-network aggregation in wireless sensor networks. We first define suitable criteria to classify existing solutions, and then describe them by separately addressing the different layers of the protocol stack while highlighting the role of a cross-layer design approach, which is likely to be needed for optimal performance. Throughout the article we identify and discuss open issues, and propose directions for future research in the area

/pdf/in-network-aggregation-techniques-for-wireless-sensor-3worsvl5sb.pdf

In-network aggregation techniques for wireless sensor networks: a survey

http://www.diit.unict.it/users/spalazzo/materiale/Electromagnetic_Nanosensors.pdf

Electromagnetic wireless nanosensor networks

Wireless sensor networks produce a large amount of data that needs to be processed, delivered, and assessed according to the application objectives. The way these data are manipulated by the sensor nodes is a fundamental issue. Information fusion arises as a response to process data gathered by sensor nodes and benefits from their processing capability. By exploiting the synergy among the available data, information fusion techniques can reduce the amount of data traffic, filter noisy measurements, and make predictions and inferences about a monitored entity. In this work, we survey the current state-of-the-art of information fusion by presenting the known methods, algorithms, architectures, and models of information fusion, and discuss their applicability in the context of wireless sensor networks.

https://www.eecs.ucf.edu/~dcm/Teaching/COT4810-Fall%202012/Literature/InformationFusionInSensorNetworks.pdf

Information fusion for wireless sensor networks: Methods, models, and classifications

Numerous transport protocols have been proposed in related work for use by mobile hosts over wireless environments. A common theme among the design of such protocols is that they specifically address the distinct characteristics of the last-hop wireless link, such as random wireless errors, round-trip time variations, blackouts, handoffs, etc. In this paper, we argue that due to the defining role played by the wireless link on a connection's performance, locating the intelligence of a transport protocol at the mobile host that is adjacent to the wireless link can result in distinct performance advantages. To this end, we present a receiver-centric transport protocol called RCP (Reception Control Protocol) that is a TCP clone in its general behavior, but allows for better congestion control, loss recovery, and power management mechanisms compared to sender-centric approaches. More importantly, in the context of recent trends where mobile hosts are increasingly being equipped with multiple interfaces providing access to heterogeneous wireless networks, we show that a receiver-centric protocol such as RCP can enable a powerful and comprehensive transport layer solution for such multi-homed hosts. Specifically, we describe how RCP can be used to provide: (i) a scalable solution to support interface specific congestion control for a single active connection; (ii) seamless server migration capability during handoffs; and (iii) effective bandwidth aggregation when receiving data through multiple interfaces, either from one server, or from multiple replicated servers. We use both packet level simulations, and real Internet experiments to evaluate the proposed protocol.

/pdf/a-receiver-centric-transport-protocol-for-mobile-hosts-with-4kk6vzad68.pdf

A receiver-centric transport protocol for mobile hosts with heterogeneous wireless interfaces

Wireless sensor networks (WSNs) are typically characterized by a limited energy supply at sensor nodes. Hence, energy efficiency is an important issue in the system design and operation of WSNs. In this paper, we introduce a novel communication paradigm that enables energy-efficient information delivery in wireless sensor networks. Compared with traditional communication strategies, the proposed scheme explores a new dimension - time, to deliver information efficiently. We refer to the strategy as Communication through Silence (CtS). We identify a key drawback of CtS - energy - throughput trade-off, and explore optimization mechanisms that can alleviate the trade-off. We then present several challenges that need to be overcome, primarily at the medium access control layer of the network protocol stack, in order to realize CtS effectively.

https://homepages.dcc.ufmg.br/~loureiro/cm/052/challenge_comm_through_silence_in_wsns.pdf

Challenges: communication through silence in wireless sensor networks

A scalable correlation aware aggregation strategy for wireless sensor networks

Correlation of data sent by different sensors in a wireless sensor network can be exploited during the data gathering process to improve energy efficiency. In this paper, we study the energy efficiency of correlation aware data aggregation trees under various sensor network conditions and the tradeoffs involved in using them. The following two related questions are specifically investigated in the study: (i) Is there any practical limit on the achievable improvement in energy efficiency in adopting a correlation aware aggregation structure as opposed to a correlation unaware structure? (ii) Is there a practical maximum useable delay bound that can deliver the maximum achievable improvement? In answering the above questions, we present comprehensive simulation results and draw inferences based on the results. We also conclude two rather surprising results that the energy improvement in using correlation aware aggregation is not significant under many network scenarios ,a nd the maximum useable delay bound is not large compared with the delay along the maximum length shortest-path in the default shortest path tree.

/pdf/practical-limits-on-achievable-energy-improvements-and-1jgeuexs51.pdf

Practical limits on achievable energy improvements and useable delay tolerance in correlation aware data gathering in wireless sensor networks

Sensors-to-sink data in wireless sensor networks (WSNs) are typically correlated with each other. Exploiting such correlation when performing data aggregation can result in considerable improvements in the bandwidth and energy performance of WSNs. In order to exploit such correlation, we present a scalable and distributed correlation-aware aggregation structure that addresses the practical challenges in the context of aggregation in WSNs. Through simulations and analysis, we evaluate the performance of the proposed approach with centralized and distributed correlation aware and unaware structures.

/pdf/a-scalable-correlation-aware-aggregation-strategy-for-3qd3dvoama.pdf

Yujie Zhu

Papers

A receiver-centric transport protocol for mobile hosts with heterogeneous wireless interfaces

Challenges: communication through silence in wireless sensor networks

A scalable correlation aware aggregation strategy for wireless sensor networks

Practical limits on achievable energy improvements and useable delay tolerance in correlation aware data gathering in wireless sensor networks

A scalable correlation aware aggregation strategy for wireless sensor networks