{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:07:10Z","timestamp":1760242030040,"version":"build-2065373602"},"reference-count":34,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2018,12,10]],"date-time":"2018-12-10T00:00:00Z","timestamp":1544400000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper investigated the throughput performance of a secondary user (SU) for a random primary user (PU) activity in a realistic experimental model. This paper proposed a sensing and frame duration of the SU to maximize the SU throughput under the collision probability constraint. The throughput of the SU and the probability of collisions depend on the pattern of PU activities. The pattern of PU activity was obtained and modelled from the experimental data that measure the wireless local area network (WLAN) environment. The WLAN signal has detected the transmission opportunity length (TOL) which was analyzed and clustered into large and small durations in the CTOL model. The performance of the SU is then analyzed and compared with static and dynamic PU models. The results showed that the SU throughput in the CTOL model was higher than the static and dynamic models by almost 45% and 12.2% respectively. Furthermore, the probability of collisions in the network and the SU throughput were influenced by the value of the minimum contention window and the maximum back-off stage. The simulation results revealed that the higher contention window had worsened the SU throughput even though the channel has a higher number of TOLs.<\/jats:p>","DOI":"10.3390\/s18124351","type":"journal-article","created":{"date-parts":[[2018,12,10]],"date-time":"2018-12-10T03:36:41Z","timestamp":1544413001000},"page":"4351","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Clustering Transmission Opportunity Length (CTOL) Model over Cognitive Radio Network"],"prefix":"10.3390","volume":"18","author":[{"given":"Mas Haslinda","family":"Mohamad","sequence":"first","affiliation":[{"name":"Research Centre of Excellence for Wireless and Photonics Network (WiPNET), Department of Computer and Communication Systems Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia"},{"name":"Center for Telecommunication Research &amp; Innovation (CeTRI), Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer (FKEKK), Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, Durian Tunggal 76100, Melaka, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aduwati","family":"Sali","sequence":"additional","affiliation":[{"name":"Research Centre of Excellence for Wireless and Photonics Network (WiPNET), Department of Computer and Communication Systems Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fazirulhisyam","family":"Hashim","sequence":"additional","affiliation":[{"name":"Research Centre of Excellence for Wireless and Photonics Network (WiPNET), Department of Computer and Communication Systems Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9254-2023","authenticated-orcid":false,"given":"Rosdiadee","family":"Nordin","sequence":"additional","affiliation":[{"name":"Centre of Advanced Electronic &amp; Communication Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3221-6714","authenticated-orcid":false,"given":"Osamu","family":"Takyu","sequence":"additional","affiliation":[{"name":"Faculty of Engineering Electrical and Computer Engineering, Shinshu University, 4-17-1, Wakasato, Nagano City 380 8553, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,12,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1109\/TVT.2014.2318512","article-title":"Which Is Better for Opportunistic Spectrum Access: The Duration-Fixed or Duration-Variable MAC Frame?","volume":"64","author":"Zhang","year":"2015","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1111","DOI":"10.1049\/iet-com.2015.1213","article-title":"Cross-layer aware joint design of sensing and frame durations in cognitive radio networks","volume":"10","author":"Zhang","year":"2016","journal-title":"IET Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1326","DOI":"10.1109\/TWC.2008.060869","article-title":"Sensing-throughput tradeoff for cognitive radio networks","volume":"7","author":"Liang","year":"2008","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.1109\/TWC.2011.020111.101870","article-title":"Effect of primary user traffic on sensing-throughput tradeoff for cognitive radios","volume":"10","author":"Tang","year":"2011","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_5","first-page":"242","article-title":"Spectrum usage in cognitive radio networks: From field measurements to empirical models","volume":"97","author":"Casadevall","year":"2014","journal-title":"IEICE Trans. Commun."},{"key":"ref_6","unstructured":"Sibomana, L., Zepernick, H.J., Tran, H., and Ngoga, S.R. (2013, January 16\u201318). Packet Transmission for Multiservice Cognitive Radio Networks with Finite Buffer Capacity. Proceedings of the 2013 19th European in Wireless Conference (EW), VDE, Guildford, UK."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1109\/JSAC.2013.130307","article-title":"Renewal-theoretical dynamic spectrum access in cognitive radio network with unknown primary behavior","volume":"31","author":"Jiang","year":"2013","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7658","DOI":"10.3390\/s150407658","article-title":"PAD-MAC: Primary User Activity-Aware Distributed MAC for Multi-Channel Cognitive Radio Networks","volume":"15","author":"Ali","year":"2015","journal-title":"Sensors"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"544","DOI":"10.1109\/JSAC.2013.130319","article-title":"Primary user traffic estimation for dynamic spectrum access","volume":"31","author":"Gabran","year":"2013","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1109\/MCOM.2007.358851","article-title":"Cognitive radios for dynamic spectrum access-dynamic spectrum access in the time domain: Modeling and exploiting white space","volume":"45","author":"Geirhofer","year":"2007","journal-title":"IEEE Commun. Mag."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Geirhofer, S., Tong, L., and Sadler, B.M. (2006, January 5). Dynamic spectrum access in WLAN channels: Empirical model and its stochastic analysis. Proceedings of the First International Workshop on Technology and Policy for Accessing Spectrum, Boston, MA, USA.","DOI":"10.1145\/1234388.1234402"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Stabellini, L. (2010, January 18\u201321). Quantifying and modeling spectrum opportunities in a real wireless environment. Proceedings of the Wireless Communications and Networking Conference (WCNC), Sydney, Australia.","DOI":"10.1109\/WCNC.2010.5506438"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jnca.2014.04.001","article-title":"Primary radio user activity models for cognitive radio networks: A survey","volume":"43","author":"Saleem","year":"2013","journal-title":"J. Netw. Comput. Appl."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2519","DOI":"10.1109\/TVT.2011.2157372","article-title":"Empirical time-dimension model of spectrum use based on a discrete-time Markov chain with deterministic and stochastic duty models","volume":"60","author":"Casadevall","year":"2011","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1109\/LCOMM.2013.012313.122442","article-title":"Energy-efficient joint design of sensing and transmission durations for protection of primary user in cognitive radio systems","volume":"17","author":"Shi","year":"2013","journal-title":"IEEE Commun. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/j.procs.2018.03.034","article-title":"Optimal Spectrum Sensing-Access Policy in Energy Harvesting Cognitive Radio Sensor Networks","volume":"129","author":"Zhang","year":"2018","journal-title":"Procedia Comput. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.1109\/LCOMM.2015.2480768","article-title":"Queueing game for spectrum access in cognitive radio networks","volume":"19","author":"Chang","year":"2015","journal-title":"IEEE Commun. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Rawat, D.B., Shetty, S., and Raza, K. (2014, January 11\u201314). Game theoretic dynamic spectrum access in cloud-based cognitive radio networks. Proceedings of the 2014 IEEE International Conference on Cloud Engineering (IC2E), Boston, MA, USA.","DOI":"10.1109\/IC2E.2014.16"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"995","DOI":"10.1109\/TWC.2009.080257","article-title":"Content-aware multiple access protocol for cooperative packet speech communications","volume":"8","author":"Kwasinki","year":"2009","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"844","DOI":"10.1109\/TWC.2011.011111.100216","article-title":"Coalitional Game Theoretic Approach for Secondary Spectrum Access in Cooperative Cognitive Radio Networks","volume":"10","author":"Li","year":"2011","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1109\/JSTSP.2011.2175699","article-title":"Coalitional games in partition form for joint spectrum sensing and access in cognitive radio networks","volume":"6","author":"Saad","year":"2012","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2470","DOI":"10.1109\/TWC.2013.031813.121135","article-title":"Joint spectrum sensing and access evolutionary game in cognitive radio networks","volume":"12","author":"Jiang","year":"2013","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e3217","DOI":"10.1002\/ett.3217","article-title":"Efficient rendezvous schemes for fast-varying cognitive radio ad hoc networks","volume":"28","author":"Sali","year":"2017","journal-title":"Trans. Emerg. Telecommun. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1449","DOI":"10.1109\/TMC.2014.2356475","article-title":"Multicast rendezvous in fast-varying DSA networks","volume":"14","author":"Rahbari","year":"2015","journal-title":"IEEE Trans. Mob. Comput."},{"key":"ref_25","first-page":"326","article-title":"Sensing-Throughput Tradeoff for Cognitive Radio Networks","volume":"7","author":"Liang","year":"2008","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kalamkar, S.S., and Banerjee, A. (2014, January 15). On the effect of primary user traffic on secondary throughput and outage probability under Rayleigh flat fading channel. Proceedings of the International Conference Signal Process and Communication, SPCOM 2014, Bangalore, India.","DOI":"10.1109\/SPCOM.2014.6983983"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2118","DOI":"10.1109\/TVT.2012.2236116","article-title":"Improving the Sensing\u2013Throughput Tradeoff for Cognitive Radios in Rayleigh Fading Channels","volume":"62","author":"Soltanmohammadi","year":"2013","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Sharkasi, Y.F., McLernon, D.C., Ghogho, M., and Zaidi, S.A.R. (2013, January 8\u201311). On spectrum sensing, secondary and primary throughput, under outage constraint with noise uncertainty and flat fading. Proceedings of the 2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), London, UK.","DOI":"10.1109\/PIMRC.2013.6666270"},{"key":"ref_29","first-page":"749","article-title":"Energy Detection Based Sensing and Primary User Traffic Classification for Cognitive Radio","volume":"2016","author":"Trivedi","year":"2016","journal-title":"World Acad. Sci. Eng. Technol. Int. J. Electr. Comput. Energy Electron. Commun. Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1186\/s13638-014-0238-5","article-title":"Analysis of Opportunistic Spectrum Access in Cognitive Radio Networks using Hidden Markov Model with State Prediction","volume":"2015","author":"Wang","year":"2015","journal-title":"EURASIP J. Wirel. Commun. Netw."},{"key":"ref_31","unstructured":"Weidling, F., Datla, D., Petty, V., Krishnan, P., and Minden, G.J. (2005, January 8\u201311). A framework for RF spectrum measurements and analysis. Proceedings of the First IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN 2005), Baltimore, MD, USA."},{"key":"ref_32","unstructured":"Press, W.H., Teukolsky, S.A., Vetterling, W.T., and Flannery, B.P. (2007). Numerical Recipes: The Art of Scientific Computing, Cambridge University Press. [3rd ed.]."},{"key":"ref_33","unstructured":"Papoulis, A., and Pillai, S.U. (2002). Probability, Random Variables, and Stochastic Processes, McGraw- Hill, Inc.. [4th ed.]."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1109\/49.840210","article-title":"Performance analysis of the IEEE 802.11 distributed coordination function","volume":"18","author":"Bianchi","year":"2000","journal-title":"IEEE J. Sel. Areas Commun."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/12\/4351\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:32:33Z","timestamp":1760196753000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/12\/4351"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,12,10]]},"references-count":34,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2018,12]]}},"alternative-id":["s18124351"],"URL":"https:\/\/doi.org\/10.3390\/s18124351","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2018,12,10]]}}}