4 research outputs found
Wi-Fi Offload: Tragedy of the Commons or Land of Milk and Honey?
Fueled by its recent success in provisioning on-site wireless Internet
access, Wi-Fi is currently perceived as the best positioned technology for
pervasive mobile macro network offloading. However, the broad transitions of
multiple collocated operators towards this new paradigm may result in fierce
competition for the common unlicensed spectrum at hand. In this light, our
paper game-theoretically dissects market convergence scenarios by assessing the
competition between providers in terms of network performance, capacity
constraints, cost reductions, and revenue prospects. We will closely compare
the prospects and strategic positioning of fixed line operators offering Wi-Fi
services with respect to competing mobile network operators utilizing
unlicensed spectrum. Our results highlight important dependencies upon
inter-operator collaboration models, and more importantly, upon the ratio
between backhaul and Wi-Fi access bit-rates. Furthermore, our investigation of
medium- to long-term convergence scenarios indicates that a rethinking of
control measures targeting the large-scale monetization of unlicensed spectrum
may be required, as otherwise the used free bands may become subject to
tragedy-of-commons type of problems.Comment: Workshop on Spectrum Sharing Strategies for Wireless Broadband
Services, IEEE PIMRC'13, to appear 201
IEEE 802.11p Transmission Using GNURadio
In this work we present an implementation of a
fully functional IEEE 802.11p transmitter in software-defined
radio. We describe the rapid-prototyping methodology that was
used to implement the frame-encoder within the open-source
GNU Software Radio (GNURadio) platform [1]. The encoder
generates OFDM frames in digital complex base-band representation
and uses the USRP2 [2] as digital-to-analog front-end for
up-conversion and final transmission. Since the actual encoding
process involves a large number of complex steps we split
the development approach into three sequential stages. First, a
reference-encoder in a high-level language (MATLAB) is derived
from the IEEE standard documents. Second, the individual
blocks of the MATLAB encoding chain are progressively ported
to GNURadio, cross-checking with the reference after each step.
Finally, standard compliance is verified by conducting comparative
over-the-air measurements with an early prototype of a
commercial 11p transceiver. Initial measurement results indicate
that the fidelity of the resulting GNURadio implementation is
on par with non-software-defined radio industry solutions and
capable of generating truly standard-compliant OFDM frames.
The encoder presented here has been released under GPLv3 and
is also capable of encoding frames according to the 11a and
11g amendments, thus making it a valuable building block for
upcoming software-defined radio projects