Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks
D2D coded caching, originally introduced by Ji, Caire, and Molisch, significantly improves communication efficiency by applying the multi-cast technology proposed by Maddah-Ali and Niesen to the D2D network. Most prior works on D2D coded caching are based on the assumption that all users will reques...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-03-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/26/3/250 |
| _version_ | 1797241174661005312 |
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| author | Wuqu Wang Zhe Tao Nan Liu Wei Kang |
| author_facet | Wuqu Wang Zhe Tao Nan Liu Wei Kang |
| author_sort | Wuqu Wang |
| collection | DOAJ |
| description | D2D coded caching, originally introduced by Ji, Caire, and Molisch, significantly improves communication efficiency by applying the multi-cast technology proposed by Maddah-Ali and Niesen to the D2D network. Most prior works on D2D coded caching are based on the assumption that all users will request content at the beginning of the delivery phase. However, in practice, this is often not the case. Motivated by this consideration, this paper formulates a new problem called <i>request-robust D2D coded caching</i>. The considered problem includes <i>K</i> users and a content server with access to <i>N</i> files. Only <i>r</i> users, known as requesters, request a file each at the beginning of the delivery phase. The objective is to minimize the average and worst-case delivery rate, i.e., the average and worst-case number of broadcast bits from all users among all possible demands. For this novel D2D coded caching problem, we propose a scheme based on uncoded cache placement and exploiting common demands and one-shot delivery. We also propose information-theoretic converse results under the assumption of uncoded cache placement. Furthermore, we adapt the scheme proposed by Yapar et al. for uncoded cache placement and one-shot delivery to the request-robust D2D coded caching problem and prove that the performance of the adapted scheme is order optimal within a factor of two under uncoded cache placement and within a factor of four in general. Finally, through numerical evaluations, we show that the proposed scheme outperforms known D2D coded caching schemes applied to the request-robust scenario for most cache size ranges. |
| first_indexed | 2024-04-24T18:19:08Z |
| format | Article |
| id | doaj.art-6ce3ec616a794f4391b130e987c25513 |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-04-24T18:19:08Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-6ce3ec616a794f4391b130e987c255132024-03-27T13:36:58ZengMDPI AGEntropy1099-43002024-03-0126325010.3390/e26030250Fundamental Limits of Coded Caching in Request-Robust D2D Communication NetworksWuqu Wang0Zhe Tao1Nan Liu2Wei Kang3National Mobile Communications Research Laboratory, Southeast University, Nanjing 211189, ChinaHuawei Technologies, Nanjing 210012, ChinaNational Mobile Communications Research Laboratory, Southeast University, Nanjing 211189, ChinaSchool of Information Science and Engineering, Southeast University, Nanjing 211189, ChinaD2D coded caching, originally introduced by Ji, Caire, and Molisch, significantly improves communication efficiency by applying the multi-cast technology proposed by Maddah-Ali and Niesen to the D2D network. Most prior works on D2D coded caching are based on the assumption that all users will request content at the beginning of the delivery phase. However, in practice, this is often not the case. Motivated by this consideration, this paper formulates a new problem called <i>request-robust D2D coded caching</i>. The considered problem includes <i>K</i> users and a content server with access to <i>N</i> files. Only <i>r</i> users, known as requesters, request a file each at the beginning of the delivery phase. The objective is to minimize the average and worst-case delivery rate, i.e., the average and worst-case number of broadcast bits from all users among all possible demands. For this novel D2D coded caching problem, we propose a scheme based on uncoded cache placement and exploiting common demands and one-shot delivery. We also propose information-theoretic converse results under the assumption of uncoded cache placement. Furthermore, we adapt the scheme proposed by Yapar et al. for uncoded cache placement and one-shot delivery to the request-robust D2D coded caching problem and prove that the performance of the adapted scheme is order optimal within a factor of two under uncoded cache placement and within a factor of four in general. Finally, through numerical evaluations, we show that the proposed scheme outperforms known D2D coded caching schemes applied to the request-robust scenario for most cache size ranges.https://www.mdpi.com/1099-4300/26/3/250coded cachingdevice-to-devicerequest-robustorder-optimal scheme |
| spellingShingle | Wuqu Wang Zhe Tao Nan Liu Wei Kang Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks Entropy coded caching device-to-device request-robust order-optimal scheme |
| title | Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks |
| title_full | Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks |
| title_fullStr | Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks |
| title_full_unstemmed | Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks |
| title_short | Fundamental Limits of Coded Caching in Request-Robust D2D Communication Networks |
| title_sort | fundamental limits of coded caching in request robust d2d communication networks |
| topic | coded caching device-to-device request-robust order-optimal scheme |
| url | https://www.mdpi.com/1099-4300/26/3/250 |
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