Abstract

This study is a product of the Africa Infrastructure Country Diagnostic (AICD), a project designed to expand the world's knowledge of physical infrastructure in Africa. AICD provides a baseline against which future improvements in infrastructure services can be measured, making it possible to monitor the results achieved from donor support. It also offers a solid empirical foundation for prioritizing investments and designing policy reforms in Africa's infrastructure sectors. The AICD is based on an unprecedented effort to collect detailed economic and technical data on African infrastructure. The project has produced a series of original reports on public expenditure, spending needs, and sector performance in each of the main infrastructure sectors, including energy, information and communication technologies, irrigation, transport, and water and sanitation. This report presents the key AICD findings for South Sudan, allowing the country's infrastructure situation to be benchmarked against that of its African peers. South Sudan is a newly independent country, affected by conflict, endowed with oil, but poor in terms of infrastructure and economic development. Because of these factors, both low-income, fragile states and resource-rich benchmarks will be used to evaluate its performance. Detailed comparisons will also be made with immediate regional neighbors in the East African Community (EAC). Document type: Book

Abstract

Infrastructure has made a net contribution of around one percentage point to Nigeria's improved per capita growth performance in recent years, in spite of the fact that unreliable power supply held growth back. Raising the country's infrastructure endowment to that of the region's middle-income countries could boost annual growth by around four percentage points. Nigeria has made important strides toward improving much of its infrastructure. Compared to many African peers, Nigeria has relatively advanced power, road, rail, and information and communications technology (ICT) networks that cover extensive areas of the nation's territory. In recent years, Nigeria has conducted several important infrastructure sector reforms. The ports sector has been converted to a landlord model, and terminal concessions now attract private investment on a scale unprecedented for Africa. The power sector is undergoing a restructuring, paving the way for performance improvements; the sector is finally on a path toward raising tariffs to recover a larger share of costs. Bold liberalization measures in the ICT sector have resulted in widespread, low-cost mobile services, Africa's most vibrant fixed-line sector, and major private investments in the development of a national fiber-optic backbone. A burgeoning domestic air transport sector has emerged, with strong private carriers that have rapidly attained regional significance. Document type: Book

Abstract

Improvements in infrastructure in all parts of Sudan in recent years have had a strong impact on per capita growth, contributing 1.7 percentage points. Consistent with trends in other countries, the information and communication (ICT) revolution that swept Africa contributed the most to Sudan. Raising the infrastructure endowment of all parts of Sudan to that of the region's best performer, Mauritius, could boosts annual growth by about 3.5 percentage points. Sudan has invested heavily in infrastructure in recent years, with some notable achievements. Power generation capacity tripled in just a few years, rising from around 800 megawatts (MW) in 2005 to 2,687MW in 2007, with a shift toward hydropower. Nevertheless, service reliability remains an issue. In ICT, Sudan has made enormous strides in liberalizing the sector and as a result has attracted significant private capital. Mobile penetration soared from less than 1 percent in 2000 to 33 percent in 2009. Recent connectivity to an undersea fiber-optic cable has led to expansions in access, improvements in quality, and reduction in prices. Looking ahead, Sudan's most pressing infrastructure challenges lie in the water and transport sectors. Sudan's infrastructure development has so far had a national focus, and there is much that remains to be done to achieve greater regional integration. While internal road corridors are developed, connectivity with neighbors is largely absent. Sudan has a natural gateway to the sea through Port Sudan but the port's performance is severely hindered by long dwell times, high costs, and capacity constraints. Looking further ahead, Sudan has the potential to be a major hydropower exporter if additional capacity could be developed and transmission links with neighboring Nile Basin countries strengthened.

Abstract

The TCP congestion control protocol is mainly designed for bandwidth symmetric paths. As two-way asymmetric connections will probably become common case in the future with the widespread use of ADSL, satellites and other high-speed technologies, it is important to make sure that congestion will be properly handled in these environments. To this end, we propose in this paper a new Adaptive Class-based Queuing mechanism called ACQ for handling two-way TCP traffic over links that exhibit bandwidth asymmetry. ACQ runs at the entry of the slow link and relies on two separate classes, one for ACK packets and one for Data packets. ACQ proposes to adapt the weights of both classes according to the crossing traffic in order to maximize some utility function defined by the user or the network operator. We show by simulations that our mechanism is able to reach a good utilization of the available resources, managing then to maximize the satisfaction of the user of such asymmetric connections. Document type: Part of book or chapter of book