 It will then describe the general solutions that the network cloud architecture uses to address those challenges. Finally, the chapter will provide more concrete examples of these concepts by describing Gigabit Passive Optical Network (GPON) access technology and wireless 5G access technology in more detail, and showing how the network cloud alters the evolution of access networks. 11.1 INTRODUCTION an all Internet protocol (IP) network, there are two predominant means of accessing the network from customer endpoints-wireline technologies and wireless technologies. Both of these tech- nologies require a highly distributed physical infrastructure, shared and allocated across multiple customers and devices. Wireline technologies are exemplified by the GPON standard, which is evolving from fixed optical wavelengths to new technologies with higher speeds and tunable wave- lengths [1]. Wireless technologies are exemplified by 4G long term evolution (4G-LTE), which is evolving into 5G technology with higher speeds, lower latencies, and support for vastly larger num- bers of devices [2]. The move to the next generation of the underlying access technologies provides Building the Network of the Future an opportunity for synergy with the move to network clouds, although the simultaneous evolution in both dimensions increases the complexity of the architectural roadmap. Access technologies create another set of challenges for network clouds. Two initial principles of NFV are that virtualized functions can be transformed from physical boxes to software running on generalized compute platforms, and that these generalized compute platforms can be located in any physical location. Network access technology, by its very nature, violates both of these initial principles. As a result, the implementation of network clouds in access networks is less mature than the implementation in core networks. However, by creating an open architectural framework that disaggregates the components of network access nodes, and by broadening the co