Monthly Archives December 2010

ylvafernaeus

A total of 8 project proposals had been submitted for the second call in 2010. The Wireless@KTH board decided on Dec 15th to follow the Program Council recommendation to fund two of these projects:

ylvafernaeus Wireless Textiles  – Project leader Ylva Fernaeus SICS, KTH participant: Dr Cristian Bogdan, CSC School,  Funding amount: 500 KSEK

The main goal with the proposed project is to develop a larger research consortium on the theme of “Wireless Textiles”, e.g. textile materials used as antennae, sensors, actuators, battery cells and charging devices for novel interactive use settings. The main deliverable will be a foundation for research grant applications based on a preparatory study, a set of initial demonstrators,and a complete list of collaborating industry partners and interest in participation.

zary_segallSemantic Resource Management for effective Mobile Services – Project Leader: Professor Zary Segall, KTH, ICT-School.   Funding amount: 500 KSEK

SRM represents an innovative way to optimize wireless communication  based on the semantic model of the mobile service requirements for wireless communication in the context of a desired QoE.The SRM goal is to optimize spectrum and energy utilization based on a model that describes the mobile service characteristics

Read more about Wireless@KTH seed project funding

JensZander_LucaStabellini_AndreasKassler_RikuJntti_MarkSmith
On Dec 17 Tekn Lic Luca Stabellini defended his Ph.D thesis succesfully. Opponent was Professor Riku Jäntti, Helsinki University of Technology, Finland. Advisor from Wireless@KTH was Professor Jens Zander. The Committee was composed of Professor Mark Smith and  Professor Björn Pehrson, KTH, Sweden and Doctor Mikael Prytz, Ericsson, Sweden.

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Professor Jens Zander, Dr Luca Stabellini, Professor Björn Pehrson, Dr Mikael Prytz and Professor Mark Smith.

Toward Reliable Wireless Sensor Networks: Energy-Aware Distributed interference Management for Unlicensed Bands

Abstract:
Wireless sensor networks have been proposed as a cost effective and easy to deploy alternative to traditional wired systems in a multitude of application scenarios ranging from industrial automation to healthcare monitoring. They are expected to enable an unparalleled number of new services that will bring countless benefits to society. However, low power communications of sensor nodes operating in unlicensed bands face several challenges and are easily corrupted by transmissions of other collocated wireless networks. This problem has recently raised reliability concerns which have been tremendously enhanced by the proliferation of wireless devices we have been witnessing during the last years in the few available regions of the spectrum.

This dissertation studies how to achieve reliable communications by proposing different ways for the energy aware management of the radio interference problem. The use of wireless sensing technologies has been envisaged in a broad variety of settings: for this reason it is not possible to identify a unifying solution for the problem of interference, but rather it is necessary to tailor the design of communication schemes accounting for the specific communication paradigm adopted by sensors, the traffic pattern generated by the expected application, as well as for the channel conditions experienced by nodes.

When packet transmissions are addressed to a single receiver, cognitive access schemes can be utilized and sensors can opportunistically select for their transmissions when to access a certain channel or which channel to access so as to avoid interference. We provide an energy aware design for communication schemes implementing these ideas and evaluate their energy performance by means of experiments using real hardware. Our results indicate that the first approach should be considered only for sporadic packet transmissions over channels presenting limited interfering activities; channel adaptation should instead be preferred for large bulks of data or when the risk of operating in heavily interfered frequency bands is high.

We further propose and evaluate a novel adaptive frequency hopping algorithm: this algorithm has been shown to be very efficient in mitigating the negative effects of interference allowing at the same time to avoid the use of the energy costly spectrum sensing algorithms required by cognitive access schemes. However, none of these three approaches may be suitable for scenarios where packet transmissions are addressed to multiple receivers. To deal with the packet losses that nodes may experience over noisy or interfered channels we envisage the use of fountain codes and show how it is possible to engineer such a coding solution so as to reduce the complexity and overhead introduced by the encoding and decoding procedures. The resulting codes provide an efficient way for disseminating data over multi-hop wireless sensor networks. Results obtained in this dissertation can be of great utility for designers of sensor applications who can use them in order to select the most energy efficient way to achieve reliable interference-aware communications.

Most of the work in the thesis was done in the WISA and WISA II projects. Funding from Vinnova/TEKES is gratefully acknowledged.

Read the Ph.D. thesis

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The Swedish regulator PTS posted on December 13 an invitation to auction of the 800 GHz band. The auction is planned to start on 28 February and those interested must apply no later than 31 January 2011.

The 800 MHz band is attractive for many different kinds of service, such as wireless broadband or mobile telephony. The band comprises six licences (2×5 MHz each). A similar auction conducted in Germany earlier this year resulted in a total of €4.38bn.

As the frequency band has good propagation characteristics, PTS is imposing a coverage requirement on one of the licences. This rollout shall take place at a fixed cost set at the auction (at least SEK 150m and at most SEK 300m).

As the spectrum was made available through the digitalization of the terrestrial television (the digital dividend), there is a risk for that television reception deployed in the 800 band is being affected when the band is started to be used. Licence holders in the 800 MHz band must therefore deal with any television reception problems that may arise from the interference.

PTS information