{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,2]],"date-time":"2025-11-02T05:29:28Z","timestamp":1762061368352,"version":"build-2065373602"},"reference-count":41,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2022,7,27]],"date-time":"2022-07-27T00:00:00Z","timestamp":1658880000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61901267"],"award-info":[{"award-number":["61901267"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Caching technique is a promising approach to reduce the heavy traffic load and improve user latency experience for the Internet of Things (IoT). In this paper, by exploiting edge cache resources and communication opportunities in device-to-device (D2D) networks and broadcast networks, two novel coded caching schemes are proposed that greatly reduce transmission latency for the centralized and decentralized caching settings, respectively. In addition to the multicast gain, both schemes obtain an additional cooperation gain offered by user cooperation and an additional parallel gain offered by the parallel transmission among the server and users. With a newly established lower bound on the transmission delay, we prove that the centralized coded caching scheme is order-optimal, i.e., achieving a constant multiplicative gap within the minimum transmission delay. The decentralized coded caching scheme is also order-optimal if each user\u2019s cache size is larger than a threshold which approaches zero as the total number of users tends to infinity. Moreover, theoretical analysis shows that to reduce the transmission delay, the number of users sending signals simultaneously should be appropriately chosen according to the user\u2019s cache size, and always letting more users send information in parallel could cause high transmission delay.<\/jats:p>","DOI":"10.3390\/e24081034","type":"journal-article","created":{"date-parts":[[2022,7,27]],"date-time":"2022-07-27T21:11:05Z","timestamp":1658956265000},"page":"1034","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Coded Caching for Broadcast Networks with User Cooperation"],"prefix":"10.3390","volume":"24","author":[{"given":"Zhenhao","family":"Huang","sequence":"first","affiliation":[{"name":"School of Information Science and Technology, ShanghaiTech University, No. 393 Huaxia Middle Road, Pudong, Shanghai 201210, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiahui","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Information Science and Technology, ShanghaiTech University, No. 393 Huaxia Middle Road, Pudong, Shanghai 201210, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaowen","family":"You","sequence":"additional","affiliation":[{"name":"School of Information Science and Technology, ShanghaiTech University, No. 393 Huaxia Middle Road, Pudong, Shanghai 201210, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shuai","family":"Ma","sequence":"additional","affiliation":[{"name":"Information Processing and Communications Laboratory, Telecom Paris, IP Paris, 91120 Palaiseau, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4383-9995","authenticated-orcid":false,"given":"Youlong","family":"Wu","sequence":"additional","affiliation":[{"name":"School of Information Science and Technology, ShanghaiTech University, No. 393 Huaxia Middle Road, Pudong, Shanghai 201210, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2856","DOI":"10.1109\/TIT.2014.2306938","article-title":"Fundamental limits of caching","volume":"60","author":"Niesen","year":"2014","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1109\/TNET.2014.2317316","article-title":"Decentralized coded caching attains order-optimal memory-rate tradeoff","volume":"23","author":"Niesen","year":"2015","journal-title":"IEEE\/ACM Trans. Netw."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1109\/TIT.2018.2870566","article-title":"Characterizing the Rate-Memory Tradeoff in Cache Networks within a Factor of 2","volume":"65","author":"Yu","year":"2019","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_4","unstructured":"Wan, K., Tuninetti, D., and Piantanida, P. (2016, January 11\u201314). On the optimality of uncoded cache placement. Proceedings of the IEEE Information Theory Workshop (ITW), Cambridge, UK."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1281","DOI":"10.1109\/TIT.2017.2785237","article-title":"The exact rate-memory tradeoff for caching with uncoded prefetching","volume":"64","author":"Yu","year":"2018","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_6","first-page":"5821","article-title":"On the placement delivery array design for centralized coded caching scheme","volume":"63","author":"Yan","year":"2017","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Zhang, D., and Liu, N. (2018, January 25\u201329). Coded cache placement for heterogeneous cache sizes. Proceedings of the IEEE Information Theory Workshop (ITW), Guangzhou, China.","DOI":"10.1109\/ITW.2018.8613420"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wang, S., and Peleato, B. (2019, January 7\u201312). Coded caching with heterogeneous user profiles. Proceedings of the IEEE International Symposium on Information Theory (ISIT), France, Paris.","DOI":"10.1109\/ISIT.2019.8849537"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Zhang, J., Lin, X., and Wang, C.C. (2015, January 14\u201319). Coded caching for files with distinct file sizes. Proceedings of the IEEE International Symposium on Information Theory (ISIT), Hong Kong, China.","DOI":"10.1109\/ISIT.2015.7282743"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Ibrahim, A.M., Zewail, A.A., and Yener, A. (2017, January 19\u201322). Centralized coded caching with heterogeneous cache sizes. Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC), San Francisco, CA, USA.","DOI":"10.1109\/WCNC.2017.7925535"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"5321","DOI":"10.1109\/TCOMM.2019.2914393","article-title":"Coded caching for heterogeneous systems: An Optimization Perspective","volume":"67","author":"Ibrahim","year":"2019","journal-title":"IEEE Trans. Commun."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4657","DOI":"10.1109\/TCOMM.2017.2734767","article-title":"Decentralized caching and coded delivery with distinct cache capacities","volume":"65","author":"Amiri","year":"2017","journal-title":"IEEE Trans. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"6112","DOI":"10.1109\/TCOMM.2019.2921711","article-title":"Coded caching with asymmetric cache sizes and link qualities: The two-user case","volume":"67","author":"Cao","year":"2019","journal-title":"IEEE Trans. Commun."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1146","DOI":"10.1109\/TIT.2016.2639522","article-title":"Coded caching with nonuniform demands","volume":"63","author":"Niesen","year":"2017","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1109\/TIT.2017.2768517","article-title":"Coded caching under arbitrary popularity distributions","volume":"64","author":"Zhang","year":"2018","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"836","DOI":"10.1109\/TNET.2015.2394482","article-title":"Online coded caching","volume":"24","author":"Pedarsani","year":"2016","journal-title":"IEEE\/ACM Trans. Netw."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1893","DOI":"10.1109\/TIT.2019.2962495","article-title":"Optimization of heterogeneous coded caching","volume":"66","author":"Daniel","year":"2020","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"7253","DOI":"10.1109\/TIT.2016.2614722","article-title":"Multi-server coded caching","volume":"62","author":"Shariatpanahi","year":"2016","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_19","first-page":"3142","article-title":"Fundamental limits of cache-aided wireless BC: Interplay of coded-caching and CSIT feedback","volume":"63","author":"Zhang","year":"2017","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6996","DOI":"10.1109\/TIT.2018.2835507","article-title":"Noisy broadcast networks with receiver caching","volume":"64","author":"Bidokhti","year":"2018","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Sengupta, A., Tandon, R., and Simeone, O. (2016, January 15\u201318). Cache aided wireless networks: Tradeoffs between storage and latency. Proceedings of the 2016 Annual Conference on Information Science and Systems (CISS), Princeton, NJ, USA.","DOI":"10.1109\/CISS.2016.7460522"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Tandon, R., and Simeone, O. (2016, January 10\u201315). Cloud-aided wireless networks with edge caching: Fundamental latency trade-offs in fog radio access networks. Proceedings of the IEEE International Symposium on Information Theory (ISIT), Barcelona, Spain.","DOI":"10.1109\/ISIT.2016.7541655"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3212","DOI":"10.1109\/TIT.2016.2557804","article-title":"Hierarchical coded caching","volume":"62","author":"Karamchandani","year":"2016","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wang, K., Wu, Y., Chen, J., and Yin, H. (2019, January 7\u201312). Reduce transmission delay for caching-aided two-layer networks. Proceedings of the IEEE International Symposium on Information Theory (ISIT), France, Paris.","DOI":"10.1109\/ISIT.2019.8849624"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Wan, K., Ji, M., Piantanida, P., and Tuninetti, D. (2018, January 20\u201324). Caching in combination networks: Novel multicast message generation and delivery by leveraging the network topology. Proceedings of the IEEE International Conference on Communications (ICC), Kansas City, MO, USA.","DOI":"10.1109\/ICC.2018.8422197"},{"key":"ref_26","first-page":"3092","article-title":"Fundamental limits of cache-aided interference management","volume":"63","author":"Naderializadeh","year":"2017","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"7464","DOI":"10.1109\/TIT.2017.2717912","article-title":"Fundamental tradeoff between storage and latency in cache-aided wireless interference Networks","volume":"63","author":"Xu","year":"2017","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3923","DOI":"10.1109\/TIT.2017.2695611","article-title":"Order-optimal rate of caching and coded multicasting with random demands","volume":"63","author":"Ji","year":"2017","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Ji, M., Tulino, A.M., Llorca, J., and Caire, G. (2015, January 8\u201311). Caching in combination networks. Proceedings of the 2015 49th Asilomar Conference on Signals, Systems and Computers, Pacific Grove, CA, USA.","DOI":"10.1109\/ACSSC.2015.7421346"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Ravindrakumar, V., Panda, P., Karamchandani, N., and Prabhakaran, V. (2016, January 10\u201315). Fundamental limits of secretive coded caching. Proceedings of the IEEE International Symposium on Information Theory (ISIT), Barcelona, Spain.","DOI":"10.1109\/ISIT.2016.7541334"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3099","DOI":"10.1109\/TIT.2018.2800059","article-title":"Coded caching schemes with reduced subpacketization from linear block codes","volume":"64","author":"Tang","year":"2018","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1732","DOI":"10.1109\/TIT.2020.3049074","article-title":"Linear coded caching scheme for centralized networks","volume":"67","author":"Cheng","year":"2021","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1109\/TIT.2020.3036313","article-title":"On coded caching with private demands","volume":"67","author":"Wan","year":"2021","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2219","DOI":"10.1109\/TIT.2020.2969918","article-title":"Rate-memory trade-off for caching and delivery of correlated sources","volume":"66","author":"Hassanzadeh","year":"2020","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1109\/TIT.2015.2504556","article-title":"Fundamental limits of caching in wireless D2D networks","volume":"62","author":"Ji","year":"2016","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Tebbi, A., and Sung, C.W. (2017, January 6\u20138). Coded caching in partially cooperative D2D communication networks. Proceedings of the 9th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT), Munich, Germany.","DOI":"10.1109\/ICUMT.2017.8255121"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3388","DOI":"10.1109\/TCOMM.2019.2893942","article-title":"Placement delivery array design for coded caching scheme in D2D Networks","volume":"67","author":"Wang","year":"2019","journal-title":"IEEE Trans. Commun."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1109\/TWC.2017.2762661","article-title":"Spatially correlated content caching for device-to-device communications","volume":"17","author":"Malak","year":"2018","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Ibrahim, A.M., Zewail, A.A., and Yener, A. (2019). Device-to-Device coded caching with distinct cache sizes. arXiv.","DOI":"10.1109\/ICC.2018.8422195"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1109\/TWC.2018.2879358","article-title":"Optimizing MDS coded caching in wireless networks with device-to-device communication","volume":"18","author":"Pedersen","year":"2019","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"854","DOI":"10.1109\/JIOT.2016.2584538","article-title":"Fog and IoT: An overview of research opportunities","volume":"3","author":"Chiang","year":"2016","journal-title":"IEEE Internet Things J."}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/24\/8\/1034\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:57:28Z","timestamp":1760140648000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/24\/8\/1034"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,27]]},"references-count":41,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["e24081034"],"URL":"https:\/\/doi.org\/10.3390\/e24081034","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2022,7,27]]}}}