1. Working Group 4B: Network Timing Single Source Risk Reduction Status Update September 21, 2015 Jennifer A. Manner, Chair

2. 2 WG4B Objectives Working Group Description: Synchronized network timing (time of day, standard time intervals, standard frequencies, and corrections) is a crucial element of a communications network management. However, given the high dependence of the communications sector on GNSS, the Commission is interested in identifying ways to increase the resilience of communications networks by exploring complementary or backup solutions that could be employed to offer similar time precision as GNSS in the event that GNSS signals are lost. These solutions need to be independent of GNSS to reduce risk and solutions need to be employed across the sector. Deliverables: The Working Group will make recommendations on acquiring and implementing back-up precision timing solutions that are independent of GPS. – Define the problem, including vulnerability of the GNSS systems, and what is the impact of the result of any failure – Define required characteristics for back-up solution – Identify what technologies are possible to solve the problem and the pros and cons of each

3. 3 WGX Members Ahmad Armand, T-Mobile Dennis Coleman, CenturyLink Lee Cosart, Microsemi (ATIS) Bill Coward, Cox Alexander Gerdenitsch, EchoStar Ethan Lucarelli, Iridium (Wiley Rein) Jennifer A. Manner, EchoStar (Chairman) Chris Oberg, Verizon Bill Ryan, DHS Rob Seastrom, TWC George Turetsky, Intel (ATIS) Joan Vaughn, T-Mobile Sameer Vuyyuru, TCS

4. 4 WG4B draws on a wide range of expertise on the issue of timing – Technical, operational, legal, process expertise – Across all technologies – wireline, terrestrial, space-based We have defined our deliverables and beginning work right away on our first deliverable: – Defining the problem This work will ensure we are all in sync on what we are seeking to solve Next we move to defining the requirements for the solutions we are evaluating WG4B Status

5. 5 Bi-weekly conference calls with members Date February 2016: Submission of Draft WG4B Report 1 June 2016: Submission of Draft WG4B Report 2 Date December 2016: Submission of Final WG4B 1 Report March 2017: Submission of Final WG4B Report 2 WG4B Schedule

6. 6 Next Steps Begin bi-weekly calls We are identifying experts for each deliverable Research issues and solutions for analysis by WG4B Provide periodic status updates to Steering Committee and Council