Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum
In this paper, the achievable latency-reliability performance of a standalone cellular network over the 5 GHz unlicensed spectrum is analysed. Fulfilling strict latency-reliability requirements comes with significant challenges for unlicensed operation, especially due to mandatory channel access pro...
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| Format: | Article |
| Language: | English |
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IEEE
2020-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/9023470/ |
| _version_ | 1818608552746418176 |
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| author | Roberto Maldonado Claudio Rosa Klaus I. Pedersen |
| author_facet | Roberto Maldonado Claudio Rosa Klaus I. Pedersen |
| author_sort | Roberto Maldonado |
| collection | DOAJ |
| description | In this paper, the achievable latency-reliability performance of a standalone cellular network over the 5 GHz unlicensed spectrum is analysed. Fulfilling strict latency-reliability requirements comes with significant challenges for unlicensed operation, especially due to mandatory channel access procedures. Using MulteFire as the reference system-model, an analysis of a highly realistic multi-cell network with bi-directional traffic shows that latency of 23 ms with a reliability level of 99.99% is achievable for low-loads, while latency is increased to 79 ms at high-loads. Different techniques are described to improve the system performance. First, a pre-emptive scheme to cope with continuous uplink listen before talk (LBT) failures for uplink control transmissions is proposed. It provides a latency reduction of 24% at low-loads with two transmission opportunities and 11% for high-loads with three opportunities. Secondly, the possibility of skipping LBT performance under given conditions is evaluated. This results in a lower uplink LBT failure rate which translates to a latency reduction of 8% for low-loads and up to 14% for high-loads, at 99.99% reliability. Thirdly, as an alternative to grant-based uplink, grant-free uplink is evaluated. Grant-free uplink achieves better performance than grant-based uplink at low-loads, offering 50% lower uplink latency. At high-loads, the gain of grant-free uplink decreases due to the high number of simultaneous transmissions. |
| first_indexed | 2024-12-16T14:44:28Z |
| format | Article |
| id | doaj.art-ae998b8d244c42d899acf1aee5eb11b3 |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-12-16T14:44:28Z |
| publishDate | 2020-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-ae998b8d244c42d899acf1aee5eb11b32022-12-21T22:27:48ZengIEEEIEEE Access2169-35362020-01-018494124942310.1109/ACCESS.2020.29780329023470Latency and Reliability Analysis of Cellular Networks in Unlicensed SpectrumRoberto Maldonado0https://orcid.org/0000-0002-1691-6924Claudio Rosa1Klaus I. Pedersen2https://orcid.org/0000-0001-8374-7705Electronic Systems Department, Wireless Communications Networks (WCN) Section, Aalborg University, Aalborg, DenmarkNokia Bell Labs, Aalborg, DenmarkNokia Bell Labs, Aalborg, DenmarkIn this paper, the achievable latency-reliability performance of a standalone cellular network over the 5 GHz unlicensed spectrum is analysed. Fulfilling strict latency-reliability requirements comes with significant challenges for unlicensed operation, especially due to mandatory channel access procedures. Using MulteFire as the reference system-model, an analysis of a highly realistic multi-cell network with bi-directional traffic shows that latency of 23 ms with a reliability level of 99.99% is achievable for low-loads, while latency is increased to 79 ms at high-loads. Different techniques are described to improve the system performance. First, a pre-emptive scheme to cope with continuous uplink listen before talk (LBT) failures for uplink control transmissions is proposed. It provides a latency reduction of 24% at low-loads with two transmission opportunities and 11% for high-loads with three opportunities. Secondly, the possibility of skipping LBT performance under given conditions is evaluated. This results in a lower uplink LBT failure rate which translates to a latency reduction of 8% for low-loads and up to 14% for high-loads, at 99.99% reliability. Thirdly, as an alternative to grant-based uplink, grant-free uplink is evaluated. Grant-free uplink achieves better performance than grant-based uplink at low-loads, offering 50% lower uplink latency. At high-loads, the gain of grant-free uplink decreases due to the high number of simultaneous transmissions.https://ieeexplore.ieee.org/document/9023470/Latencyreliabilityunlicensed spectrumMulteFirelisten before talkradio resource management |
| spellingShingle | Roberto Maldonado Claudio Rosa Klaus I. Pedersen Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum IEEE Access Latency reliability unlicensed spectrum MulteFire listen before talk radio resource management |
| title | Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum |
| title_full | Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum |
| title_fullStr | Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum |
| title_full_unstemmed | Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum |
| title_short | Latency and Reliability Analysis of Cellular Networks in Unlicensed Spectrum |
| title_sort | latency and reliability analysis of cellular networks in unlicensed spectrum |
| topic | Latency reliability unlicensed spectrum MulteFire listen before talk radio resource management |
| url | https://ieeexplore.ieee.org/document/9023470/ |
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