cture expenditure is the main part of a wireless network operator's fixed cost and any reduction can boost overall business performance. Moreover, there is a shortage of infrastructure roll-out engineers and fewer installations can speed up service roll-out for all operators. Clearly there are economic efficiencies by rolling out a single set of wireless infrastructure for all service providers. One may envision a future where only one set of network infrastructure exists, which is owned or managed by a third party. All operators in this model will be in effect virtual network operators - although they will still own spectrum. This is the complete opposite of the model where every operator owns and manages their wireless infrastructure. While the joint owner- ship of the infrastructure provides significant cost saving, it also removes any competitive advantages an operator may enjoy through having a superior coverage. The likely scenario will therefore be somewhere between the two: operators may jointly own and manage part of their infrastructure and separately own other parts. Unfettered access further envisions a future characterised by net-neutrality where service providers treat all content streams equally. It should be noted that the NGN vision of ITU is aspirational and not necessarily mandatory. Different governments may legislate to enforce any of these desired outcomes. Fixed Mobile Convergence Another aspect of NGN is supporting organised mobility and seamless access to broadband infrastructure in both fixed and mobile form. This is known as fixed mobile convergence (FMC) and envisions delivery of packets to/from an end-user device using the most efficient route (e.g. through a wide area network such as LTE, or via LAN or wireless LAN, or through even a personal area network). A single device IP address will remain unique and is recog- nised and located by the delivery network. This is illustrated in Figure 13.23. As packet transport is over multiple networks, each possibly owned by a different service 