hapter, you will learn the following: Deployment considerations for mobile timing: Covers the different factors to consider when building a solution for 5G timing. These factors reflect the choices that a 5G operator has made about the form of network that they are building. Frequency-only deployments: Covers those cases where phase synchronization is not a re- quirement. This is unlikely to include most 5G networks, but many LTE and LTE-A networks may fall into this category, and many times will be coexisting alongside the new 5G elements. Frequency, phase, and time deployment options: Details the different solutions to apply to each situation, based on the constraints that the operator must deal with. mid-haul and front-haul timing: Expands on previous chapters discussing the front-haul evol- ution and explains the various topologies underlying modern radio access network (RAN) designs. Timing security and MACsec: Follows preceding discussions about precision time protocol (PTP) security to deal with other aspects of security such as using IPsec and MACsec for trans- port security. It is time to bring together all the threads running through the preceding chapters. The early chapters presented the underlying principles and features of timing and synchronization. Then, the middle chapters included the particulars of the appropriate tools to carry synchronization across a network. Then, later chapters looked at how to design a synchronization network and started to in- troduce the details of applying these tools to assist the rollout of 5G mobile. "Chapter 10. Mobile Timing Requirements", then covered many of the requirements of synchronization for the 5G back- haul and front-haul networks. This chapter now goes through the numerous approaches to deploying a synchronization solution to support all the different 5G network use cases. This takes into account factors like what is the ap- propriate tool for each situation, what are the pros/cons behind different network topologies, and what is the best way to solve t