broadband strategies handbook.pdf - Khazar University

The Broadband Supply ChainThe broadband supply chain has four main infrastructure components(figure 5.1):• International connectivity provides links to broadband networks in othercountries usually via satellite and fiber optic cable. This requires networkintelligence to exchange and route international Internet traffic.• National backbone network provides pathways for transmitting Internetdata across a country, typically via microwave, satellite, and fiber opticlinks. This also includes traffic management, exchange, and routing aswell as issues related to enhancing efficiency and quality over IP networkssuch as Internet exchanges, metropolitan rings, and next-generation networks(NGNs).• Metropolitan or backhaul links provide the connections between localareas and the national backbone network, usually via fiber optic andmicrowave and, to a lesser extent, satellite. In a wireless network,these links are used to bring traffic from cell sites back to a switchingcenter (known as backhaul).• Local access networks provide the wireline and wireless infrastructurethat end users utilize to connect to the broadband network.The boundaries between these network components are sometimesblurred. For example, Internet traffic exchanges route domestic traffic.However, they are also related to international traffic in that the exchangemay be a peering point for an overseas network. Internet exchanges alsoreduce reliance on international connectivity by ensuring that domestictraffic is kept within the country. Metropolitan ring networks provide abridge between the domestic backbone network and the various local accessnetworks. There are also regional implications in that one country’s nationalbackbone could provide an international connectivity link for a neighboringlandlocked country.Two additional points should be noted. First, the different levels of theoverall broadband network should ideally be in sync. High speeds in thelocal access network segment can only be accomplished if the speed andcapacity in the national and international network segments are adequateto support them. Second, technology deployment is dependent on a country’sexisting level of infrastructure. Countries without significant wirelineinfrastructure in the local access network may find it financially impracticalto deploy ubiquitous wired networks, but they may be able to upgrade existingwireless networks. Similarly, countries often find it more financiallyTechnologies to Support Deployment of Broadband Infrastructure 197