December 09, 2018

On the Impact of Listen-Before-Talk on Ultra-Reliable Low-Latency Communications

  • Frederiksen F.
  • Maldonado R.
  • Pedersen K.
  • Rosa C.

In this paper, we study the performance of ultrareliable low latency communication (URLLC) for cellular standalone systems in unlicensed bands. Our focus is on the 5 GHz band, adopting a system model in coherence with the MulteFire standard, which essentially is a variant of LTE (Long Term Evolution) for unlicensed band operation.We show that especially the mandatory Listen Before Talk (LBT) procedure is a challenge for achieving low latency communication. Our theoretical analysis indicated that the impact of the LBT procedure prior to downlink transmissions can be significant, taking values of 3- 25 ms for the considered offered load levels. Furthermore, our advanced dynamic system level simulations show that the time spent performing LBT often accounts for 18%-42% of the packet latency budget, depending on the considered outage level and offered traffic. Therefore LBT represents a major challenge for achieving URLLC-alike performance in unlicensed spectrum.

Recent Publications

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  • Kamat S.
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This paper takes a fresh look at the debate over the relationship between digital technology and productivity. The argument of economic historian Robert J. Gordon is that digital technology will not lead to increases in productivity such as we saw in the last century, based on his analysis of the ...

January 01, 2019

Friendly, appealing or both? Characterising user experience in sponsored search landing pages

  • Bron M.
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© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Many of today's websites have recognised the importance of mobile friendly pages to keep users engaged and to provide a satisfying user experience. However, next to the experience provided by the sites themselves, ...

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  • Aiello L.
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© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Uber is a popular ride-sharing application that matches people who need a ride (or riders) with drivers who are willing to provide it using their personal vehicles. Despite its growing popularity, there exist ...