*Second Announcement and Call for Papers - Registration is now open* Dear colleagues, We are pleased to announce the INFORMS Telecommunications and Network Analytics Conference (TNAC), which will take place at Zuse Institute Berlin (ZIB), on March 29 - April 1, 2020 in Berlin, Germany (http://informs_tnac2020.zib.de/). INFORMS TNAC 2020 (previously INFORMS Telecommunications Conference) is the 15th of bi-annual conferences held by the INFORMS Telecommunications and Network Analytics Section. The conference is going to be focused on the theory and application of operations research and management science to problems in telecommunications and network analytics, with particular emphasis on new and emerging technologies. Additionally, the conference is going to provide a platform for academics and industry experts working in telecommunications and network analytics to exchange ideas and initiate new collaborations, as in previous conferences. Submissions from the interested researchers are welcome for an organized session with 3-4 presentations, a tutorial session or a single presentation. The topics of interest include (but are not limited to):  * Telecommunications modeling, policy and technology;  * Data mining and big data applications in telecommunications;  * Machine learning and artificial intelligence in network analytics;  * Network economics;  * Network design;  * Traffic routing;  * Network optimization;  * Network algorithms and metaheuristics;  * Sensor networks;  * Wireless and broadband networks;  * Vehicle and mobile computing;  * Cloud computing and fog computing;  * Semantic networks;  * Network survivability and reliability;  * Information security and privacy;  * Game theory applications;  * Internet and multimedia;  * Quality of service. The abstract submission system is available online at https://easychair.org/conferences/?conf=informstnac2020. Proposals for organized sessions or tutorials can be directly submitted to *informs_tnac2020@zib.de*. Registration is now *OPEN* at: http://informs_tnac2020.zib.de/registration.html *Important dates* Abstract Submission Deadline - January 15, 2020. Acceptance Notification for Presentations - February 1, 2020. End of Early Bird Registration - February 15, 2020. *Keynote speakers* Prof. Bernard Fortz - Université Libre de Bruxelles Prof. Bernard Gendron - Université de Montréal/ Interuniversity Research Centre on Enterprise Networks, Logistics and Transportation (CIRRELT) A special issue of the international journal Networks(ISSN:1097-0037) on “Telecommunications and Network Analytics” will follow the conference. We are looking forward to your contributions and to greeting you in Berlin in 2020! The Organization Committee: Thorsten Koch, Conference Chair– Zuse Institute Berlin Haldun Süral – Middle East Technical University Christine Tawfik – Zuse Institute Berlin Inci Yüksel-Ergün – Zuse Institute Berlin