But operators can be reluctant to invest in areas where commercial returns are uncertain. In these cases, governments have intervened, entering into public-private partnerships (PPPs) to invest in broadband infrastructure. This section describes these PPP investment strategies, using case studies to illustrate the key characteristics of each approach.1.3.1 Overview of PPPs A European Commission and an ITU study have broadly defined PPPs20 and identified investment models commonly used for broadband PPP projects21 22. Most PPP projects in broadband infrastructure tend to fall into one of the following funding model categories:• Private design, build and operate (DBO) – where a private operator retains ownership and control of the broadband network. The private operator may benefit from receiving state funds to invest in broadband infrastructure in commercially unviable areas.• Public outsourcing – where a private operator is responsible for running a network under a government-funded contract. The government normally retains ownership of the network after the contract expires.• Joint venture (JV) – where a special-purpose vehicle (SPV) or separate legal entitiy is created by the private operator and the government to invest in broadband infrastructure in commercially unviable areas. The private operator and the government share the funding, network ownership and day-to-day management responsibility.• Public DBO – where the government has full funding responsibility and full ownership of the network assets. Elements of the day-to-day management may be allocated to private contractors.The EC and ITU reports also identified common funding sources for broadband projects. These included government grants, universal service funding and external funding from non-governmental organizations (NGOs) and international development banks. Note that the \"bottom-up\" model has been excluded from the list of the most common investment models. This approach involves community-driven investment, and it is described in more detail in Section 1.5, where alternative investment approaches are discussed.The four above-mentioned models involve variations of public- and private-sector intervention. Each model’s approach varies based on three main characteristics:– the funding source for the roll-out and operation of the infrastructure;– responsibility for deploying infrastructure and running operations; and – ownership of the infrastructure (see Table 1.2).The most suitable investment approach for a particular project can depend on a range of variables, including the market structure, the level of Internet maturity and the political landscape. The government’s experience in funding, owning and running broadband networks is also an important consideration when deciding which investment approach should be taken. The key advantages and disadvantages of the investment approaches are summarized in Table 1.2. The following sections provide as least one case study or example for each type of PPP investment approach. They also discusss the role of the regulator in attracting broadband infrastructure investment and list key lessons to be taken from each project.1.3.2 Private DBOs In this investment model, the private sector (usually a network operator) designs, builds and operates the broadband infrastructure on behalf of the government. The infrastructure typically is made available to other service providers and Internet service providers (ISPs) on a wholesale and open-access basis. It should be noted, however, that the infrastructure remains under the network operator’s ownership, which does not transfer to the government.In this approach, government intervention is limited to funding. The private operator retains control over the design of the network and retains the network assets. The government has limited Trends in Telecommunication Reform 2016 7 Chapter 1