{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T03:01:31Z","timestamp":1760151691171,"version":"build-2065373602"},"reference-count":33,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,3,31]],"date-time":"2022-03-31T00:00:00Z","timestamp":1648684800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Future Internet"],"abstract":"<jats:p>Phone of Things (PoT) extends the connectivity options for IoT systems by leveraging the ubiquitous phone network infrastructure, making it part of the IoT architecture. PoT enriches the connectivity options of IoT while promoting its affordability, accessibility, security, and scalability. PoT enables incentive IoT applications that can result in more innovative homes, office environments, and telephony solutions. This paper presents the Location Transparency Call (LTC) system, an intelligent phone dialing system for businesses based on the PoT architecture. The LTC system intelligently mitigates the impact of missed calls on companies and provides high availability and dynamic reachability to employees within the premises. LTC automatically forwards calls to the intended employees to the closest phone extensions at their current locations. Location transparency is achieved by actively maintaining and dynamically updating a real-time database that maps the persons\u2019 locations using the RFID tags they carry. We demonstrate the system\u2019s feasibility and usability and evaluate its performance through a fully-fledged prototype representing its hardware and software components that can be applied in real situations at large scale.<\/jats:p>","DOI":"10.3390\/fi14040111","type":"journal-article","created":{"date-parts":[[2022,3,31]],"date-time":"2022-03-31T21:33:03Z","timestamp":1648762383000},"page":"111","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Location Transparency Call (LTC) System: An Intelligent Phone Dialing System Based on the Phone of Things (PoT) Architecture"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9063-276X","authenticated-orcid":false,"given":"Haytham","family":"Khalil","sequence":"first","affiliation":[{"name":"Faculty of Engineering and Applied Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5892-632X","authenticated-orcid":false,"given":"Khalid","family":"Elgazzar","sequence":"additional","affiliation":[{"name":"Faculty of Engineering and Applied Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,31]]},"reference":[{"key":"ref_1","unstructured":"(2022, January 20). Missed Calls: The Real Impact on Your Business. Available online: https:\/\/aircall.io\/blog\/customer-happiness\/missed-calls\/."},{"key":"ref_2","unstructured":"(2022, January 20). UK SMEs Lose \u20a490m Due to Missed Calls. Available online: https:\/\/www.computerweekly.com\/news\/2240234997\/UK-SMEs-lose-90m-because-of-missed-calls\/."},{"key":"ref_3","unstructured":"(2022, January 20). The Co$t of a Missed Call: The Math Will Surprise You. Available online: https:\/\/www.mapcommunications.com\/cost-missed-call\/."},{"key":"ref_4","first-page":"44","article-title":"Automated Attendant Vs. Live Answering","volume":"40","author":"Stan","year":"2005","journal-title":"Westchest. Cty. Bus. J."},{"key":"ref_5","unstructured":"(2022, January 20). What Do Customers Really Think about Long Wait Times?. Available online: https:\/\/www.icmi.com\/resources\/2017\/what-do-customers-really-think-about-long-wait-times\/."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Karademir, R., and Heves, E. (2013, January 1\u20134). Dynamic interactive voice response (IVR) platform. Proceedings of the Eurocon 2013, Zagreb, Croatia.","DOI":"10.1109\/EUROCON.2013.6624972"},{"key":"ref_7","unstructured":"(2022, March 01). Twilio: Communication APIs for SMS, Voice, Video & Authentication. Available online: https:\/\/www.twilio.com\/."},{"key":"ref_8","unstructured":"Haytham, K., and Khalid, E. (July, January 14). Phone of Things (PoT): Empowering IoT Systems Through VoIP Infrastructure and Voice Commands. Proceedings of the 7th IEEE World Forum on the Internet of Things\u2014WF-IoT 2021, New Orleans, LA, USA."},{"key":"ref_9","unstructured":"Hillar, G.C. (2017). MQTT Essentials\u2014A Lightweight IoT Protocol, Packt Pub."},{"key":"ref_10","unstructured":"Simone, C., Marco, P., and Luca, V. (2013). CoSIP: A Constrained Session Initiation Protocol for the Internet of Things. Advances in Service-Oriented and Cloud Computing, Springer."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Andriopoulou, F., Orphanoudakis, T., and Dagiuklas, T. (2017, January 9\u201311). IoTA: IoT Automated SIP-Based Emergency Call Triggering System for General eHealth Purposes. Proceedings of the 2017 IEEE 13th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), Rome, Italy.","DOI":"10.1109\/WiMOB.2017.8115830"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Sangkong, J., and Ongtang, M. (2017, January 29\u201331). Smart VoIP Postbox with Confirmation Receipt Using IoT Technology. Proceedings of the 2017 International Conference on Industrial Design Engineering, Dubai, United Arab Emirates.","DOI":"10.1145\/3178264.3178283"},{"key":"ref_13","unstructured":"Melo, D.D.F., Lage, E.D.S., Rocha, A.V., and Cardoso, B.D.J. (2017, January 7\u20138). Improving the Consumption and Water Heating Efficiency in Smart Buildings. Proceedings of the 2017 13th International Conference and Expo on Emerging Technologies for a Smarter World (CEWIT), Stony Brook, NY, USA."},{"key":"ref_14","first-page":"38","article-title":"Integration of Asterisk IP-PBX with ESP32 Embedded System for Remote Code Execution","volume":"21","year":"2019","journal-title":"Multidiscip. Digit. Publ. Inst. Proc."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Hernandez, L., and Ospina, M. (2019, January 5\u20137). Scheme and Creation of a Prototype for the Supervision of Lights and Electronic Devices with a PBX, Using a WLAN Solution Based on IoT. Proceedings of the 2019 IEEE Colombian Conference on Communications and Computing (COLCOM), Barranquilla, Colombia.","DOI":"10.1109\/ColComCon.2019.8809159"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"9877","DOI":"10.1007\/s11042-020-09986-0","article-title":"Voice over internet protocol voicemail security system using two factor authentication and biometric prints with new efficient hybrid cryptosystem","volume":"80","author":"Elshamy","year":"2021","journal-title":"Multimed Tools Appl."},{"key":"ref_17","unstructured":"(2022, January 20). Cold Call Sales Voicemail Scripts That Get Callbacks. Available online: https:\/\/blog.zoominfo.com\/cold-sales-voicemails\/."},{"key":"ref_18","unstructured":"James, D., and Michael, S. (2014, January 15\u201318). SMS Notifications for Missed Calls: Expanding Mobility for TDM Environments. Proceedings of the 3rd Annual Conference on Research in Information Technology, Atlanta, GA, USA."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"NNurhalim, I., and Gunawan, D. (2011, January 17\u201319). PSTN VoIP Application Support System Design using mobile Short Message Service (SMS): Case Study of PSTN VoIP Missed Call Notification to mobile phone by SMS. Proceedings of the 2011 International Conference on Electrical Engineering and Informatics, Bandung, Indonesia.","DOI":"10.1109\/ICEEI.2011.6021629"},{"key":"ref_20","unstructured":"Aberethy, M., Grigsby, T., Paolini, M., and Potluri, L. (2013). Missed Call Integration with Voicemail and Granular Access to Voicemail. (8,594,634), US Patent."},{"key":"ref_21","unstructured":"(2021, January 20). Understanding the Impact of Voicemail. Available online: https:\/\/www.answer365.ca\/blog\/102-understanding-the-impact-of-voicemail.html."},{"key":"ref_22","unstructured":"(2022, January 20). Raspberry Pi: Teach, Learn, and Make with Raspberry Pi. Available online: https:\/\/raspberrypi.org\/."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"58","DOI":"10.17781\/P002557","article-title":"Analysis of Security Virtual Private Network (VPN) Using OpenVPN","volume":"8","author":"Muhammad","year":"2019","journal-title":"Int. J.-Cyber-Secur. Digit. Forensics"},{"key":"ref_24","unstructured":"(2022, January 20). Vultr: SSD VPS Servers, Cloud Servers and Cloud Hosting. Available online: https:\/\/www.vultr.com."},{"key":"ref_25","first-page":"5803","article-title":"Software-Defined Networking (SDN): A Survey","volume":"18","author":"Kamal","year":"2016","journal-title":"Secur. Commun. Netw."},{"key":"ref_26","unstructured":"(2022, January 20). Asterisk: Open Source Communications Software. Available online: https:\/\/asterisk.org\/."},{"key":"ref_27","unstructured":"(2022, January 20). Raspberry Pi Downloads, Software for the Raspberry Pi. Available online: https:\/\/www.raspberrypi.org\/downloads\/."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1109\/ICEDSA.2012.6507806","article-title":"A Study of SIP Trunk Security and Challenges","volume":"Volume 10","author":"Jabel","year":"2012","journal-title":"Proceedings of the 2012 IEEE International Conference on Electronics Design, Systems and Applications (ICEDSA)"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Maldonado, J.A.V., and Cuadra, J.A.G. (2019, January 23\u201325). Natural Language Interface to Database Using the DialogFlow Voice Recognition and Text Conversion API. Proceedings of the 8th International Conference On Software Process Improvement (CIMPS), Leon, Mexico.","DOI":"10.1109\/CIMPS49236.2019.9082438"},{"key":"ref_30","unstructured":"Simionovich, N. (2009). Asterisk Gateway Interface 1.4 and 1.6 Programming: Design and Develop Asterisk-Based VoIP Telephony Platforms and Services Using PHP and PHPAGI, Packt Pub."},{"key":"ref_31","unstructured":"(2022, January 20). Managed MongoDB Hosting|Database-as-a-Service|MongoDB. Available online: https:\/\/www.mongodb.com\/cloud\/atlas."},{"key":"ref_32","first-page":"409","article-title":"RFID in the Warehouse: A Literature Analysis (1995\u20132010) of Its Applications, Benefits, Challenges and Future Trends","volume":"10","author":"Sharifi","year":"2013","journal-title":"Int. J. Prod. Econ."},{"key":"ref_33","unstructured":"Szigeti, T., and Hattingh, C. (2004). End-to-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs, Cisco Press. [1st ed.]."}],"container-title":["Future Internet"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-5903\/14\/4\/111\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:47:13Z","timestamp":1760136433000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-5903\/14\/4\/111"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,31]]},"references-count":33,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2022,4]]}},"alternative-id":["fi14040111"],"URL":"https:\/\/doi.org\/10.3390\/fi14040111","relation":{},"ISSN":["1999-5903"],"issn-type":[{"type":"electronic","value":"1999-5903"}],"subject":[],"published":{"date-parts":[[2022,3,31]]}}}