ployment considerations for a timing solution targeted for mobile. It examines the trade-offs in synchronizing various types of cell sites, different topologies, radio types, and generations of mobile technology. It examines both the frequency-only case with the 4G mobile network and the additional time/phase requirements in both the 5G mobile back-haul and front- haul/mid-haul deployment. This chapter also examines the various options for the design of a timing solution based on the individual circumstances that the operator is faced with. This includes where the access network is owned by third parties, where GNSS is unavailable, and when autonomous operation of the timing solution (no reliance on GNSS) is required. Chapter 12, "Operating and Verifying Timing Solutions," covers the operational aspects of de- ploying and managing a timing solution. It introduces the hardware design techniques for clocks, explains how to define specifications for timing equipment, and provides extended cov- erage of testing timing performance. Lastly, it covers the operational aspects of configuration, management, and monitoring of a timing solution, including troubleshooting and field testing. Note that the early chapters in the book may define a few technical terms somewhat loosely. Sub- sequent chapters unlock additional technical details and offer more exacting treatment of the topics. As the details are revealed, the terminology becomes more precisely defined. As an example, at the beginning, the authors may use everyday terms-such as clocking, synchron- ization, and timing-somewhat interchangeably. Some sections talk about carrying time or trans- porting synchronization, clocking a radio, or timing a network device, when in fact, some methods of synchronization do not deal with actual time at all! The book does not give recommendations on which of these technologies should be deployed, nor does it provide a transition plan for a mobile operator. Each mobile operator can evaluate the tech- nologies and make decisions based o