es include a combination of optical networking products that operate separately or within a single converged platform called packet optical transport system such as reconfigurable optical add-drop multiplexers, time division multiplexing, and carrier Ethernet switching products. These platforms reside in the metro edge, metro core, and the long- haul networks of major service providers. 90 Chapter 1 satellite system (GNSS) methods such as global positioning system (GPS). Phase synchroni- zation is provided using IEEE 1588v2 precision timing protocol. There are a number of ways in which good network performance can improve PTP quality within the base station. The use of network elements with low jitter has a positive impact on the quality of the received PTP by reducing errors. Furthermore, networks that support both SyncE and IEEE 1588v2 are able to operate in hybrid mode, with SyncE assisting the IEEE 1588v2 protocol for an improved overall performance. Inadequate synchronization has a negative impact on network performance, resulting in less efficient radio interface, poor performance for data traffic, and dropped calls. Mobile backhaul is provisioned throughout the cellular network to transport voice and data traffic between the access and core networks. Wireless equipment in the radio access net- work includes macro-cell base stations, small-cell access points, and DASs. Wired and wire- less transport mechanisms are the two types of mobile backhaul deployed across the RANs. With the emergence of heterogeneous networks, mobile backhaul has become a critical component in the 4G and 5G networks. The cellular networks are evolving toward a heterogeneous architecture where different classes of small-cell base stations and DAS installations are coordinated, cooperating with macro-site base stations. A HetNet topology improves cellular network capacity and cover- age to support the exponential growth in mobile traffic. Subsequently, HetNets can deliver ubiquitous connectivity to the mobile users with exceptional qua