| 1. |
- Fodor, Gábor, et al.
(författare)
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Device-to-device communications for national security and public safety
- 2014
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Ingår i: IEEE Access. - 2169-3536. ; 2, s. 1510-1520
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Tidskriftsartikel (refereegranskat)abstract
- Device-to-device (D2D) communications have been proposed as an underlay to long-term evolution (LTE) networks as a means of harvesting the proximity, reuse, and hop gains. However, D2D communications can also serve as a technology component for providing public protection and disaster relief (PPDR) and national security and public safety (NSPS) services. In the United States, for example, spectrum has been reserved in the 700-MHz band for an LTE-based public safety network. The key requirement for the evolving broadband PPDR and NSPS services capable systems is to provide access to cellular services when the infrastructure is available and to efficiently support local services even if a subset or all of the network nodes become dysfunctional due to public disaster or emergency situations. This paper reviews some of the key requirements, technology challenges, and solution approaches that must be in place in order to enable LTE networks and, in particular, D2D communications, to meet PPDR and NSPS-related requirements. In particular, we propose a clustering-procedure-based approach to the design of a system that integrates cellular and ad hoc operation modes depending on the availability of infrastructure nodes. System simulations demonstrate the viability of the proposed design. The proposed scheme is currently considered as a technology component of the evolving 5G concept developed by the European 5G research project METIS.
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| 2. |
- Kildal, Per-Simon, 1951, et al.
(författare)
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MIMO Characterization on System Level of 5G Micro Base Stations Subject to Ran-domness in LOS
- 2014
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 2:2014, s. 1064 - 1077
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Tidskriftsartikel (refereegranskat)abstract
- Wireless systems have become more and more advanced in terms of handling the statistical properties of wireless channels. For example, the 4G long term evolution (LTE) system takes advantage of multiport antennas [multiple-input multiple-output (MIMO) technology] and orthogonal frequency division multiplexing (OFDM) to improve the detection probability of single bitstream by diversity in the spatial and frequency domains, respectively. The 4G system also supports transmission of two bitstreams by appropriate signal processing of the MIMO subchannels. The reverberation chamber emulates according to previous works rich isotropic multipath (RIMP) and has proven to be very useful for characterizing smart phones for LTE systems. The measured throughput can be accurately modeled by the simple digital threshold receiver, accounting accurately for both the MIMO and OFDM functions. The throughput is equivalent to the probability of detection (PoD) of the transmitted bitstream. The purpose of this paper is to introduce a systematic approach to include the statistical properties of the user and his or her terminal, when characterizing the performance. The user statistics will have a larger effect in environments with stronger line-of-sight (LOS), because the angle of arrival and the polarization of the LOS contribution vary due to the user’s orientation and practices. These variations are stochastic, and therefore, we introduce the term random-LOS to describe this. This paper elaborates on the characterization of an example antenna in both RIMP and random-LOS. The chosen antenna is a wideband microbase transceiver station (BTS) antenna.We show how to characterize the micro-BTS by the PoD of one and two bitstreams in both RIMP and random-LOS, by considering the user randomly located and oriented within the angular coverage sector. We limit the treatment to a wall-mounted BTS antenna, and assume a desired hemispherical coverage. The angular coverages of both one and two bitstreams for the random-LOS case are plotted as MIMO-coverage radiation patterns of the whole four-port digital antenna system. Such characterizations in terms of PoD have never been done before on any practical antenna system. The final results are easy to interpret, and they open up a new world of opportunities for designing and optimizing 5G antennas on system level.
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| 3. |
- Lakomaa, Erik, et al.
(författare)
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Open data as a foundation for innovation: The enabling effect of free public sector information for entrepreneurs
- 2013
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Ingår i: IEEE Access. - 2169-3536. ; 1, s. 558-563
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Tidskriftsartikel (refereegranskat)abstract
- Public open data access has a direct impact on future IT entrepreneurs' perception of ability to execute their business plans. Using high quality (50%-98% response rate) survey data from 138 Swedish ITentrepreneurs, we find that access to public open data is considered very important for many IT-startups; 43% find open data essential for the realization of their business plan and 82% claim that access would support and strengthen the business plan. The survey also indicates a significant interest in, and willingness to pay for, public sector information data from companies that do not intend to commercialize data themselves but intend to use it to support or test other business models. From the survey, it is possible to infer that the previous discourse on open data, viewing it as a means for government accountability or e-government, or as the foundation for the commercialization of public sector information data is too limited. Open data should instead be seen as an enabler of innovation outside these traditional sectors. This also indicates that the previously calculated societal values of open data might be underestimated. © 2013 IEEE.
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| 4. |
- Mubeen, Saad, et al.
(författare)
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Extending Worst-Case Response-Time Analysis for Mixed Messages in Controller Area Network with Priority and FIFO Queues
- 2014
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Ingår i: IEEE Access. - 2169-3536. ; 2, s. 365-380
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Tidskriftsartikel (refereegranskat)abstract
- The existing worst case response-time analysis for controller area network (CAN) with nodesimplementing priority and First In First Out (FIFO) queues does not support mixed messages. It assumesthat a message is queued for transmission either periodically or sporadically. However, a message canalso be queued both periodically and sporadically using mixed transmission mode implemented by severalhigher level protocols for CAN that are used in the automotive industry. We extend the existing analysisfor CAN to support any higher level protocol for CAN that uses periodic, sporadic, and mixed transmissionof messages in the systems where some nodes implement priority queues, whereas others implement FIFOqueues. In order to provide a proof of concept, we implement the extended analysis in a free tool, conductan automotive-application case study, and perform comparative evaluation of the extended analysis with theexisting analysis.
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| 5. |
- Ohlsson, Lars, et al.
(författare)
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A 15-Gb/s wireless on-off keying link
- 2014
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Ingår i: IEEE Access. - 2169-3536. ; 2, s. 1307-1313
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Tidskriftsartikel (refereegranskat)abstract
- Bit-error rate measurements for ON-OFF keying modulation at multigigabit per second rates over a V-band wireless link are presented. Serial data-rates from 2.5 to 20 Gb/s were studied for a 231-1 bit random sequence. Error-free data transfer over a 0.3-m link was achieved at up to 10 Gb/s. Acceptable bit-error rates, <10-5 and 10-3, were measured at up to 1.5 m for 10- and 15-Gb/s data-rate, respectively. The performance was achieved using a transmitter that consists of an integrated wavelet generator, whereas the receiver was built from off-the-shelf waveguide components. The results demonstrate that very high data-rates may be achieved using binary modulation and short symbols generated in an efficient V-band transmitter. The system is benchmarked against state-of-the-art transceiver systems with multigigabit per second data-rates.
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