城市的网络优势——中国互联网骨干网络结构与节点可达性分析

The network advantage of cities: an analysis of spatial structure and node accessibility of Internet backbones in China

过去十余年,中国的互联网得到飞速发展,新的基础设施空间架构也已经基本形成。本文在回顾有关通信网络与城市体系的文献基础上,尝试建立一种评价中国互联网城市可达性的方法,并对五大骨干网络的空间结构和节点可达性进行了分析。结果表明:中国互联网基础设施的空间格局整体上趋于均衡,节点可达性基本遵循原有的城市等级体系;北京、广州和上海三大国家交换中心和几大区域核心节点城市的可达性位列顶层;节点可达性的高低与城市地理区位存在紧密联系。

The rise of information economy has restructured the competitive advantage of cities in many ways in which cities rise and fall in the global economy. Although the bubble of New （Digital） Economy has collapsed, Internet continues to be a driving force in many places. In these local economies, the leading infrastructure is not highways, ports, rail-ways, or airports, but fiber optic glass network connected around the world. With rapid advances in Internet technology, the spatial framework of telecommunication infrastructure has also been developed rapidly China during the last decade. However, little advances in academic research on Internet, especially the relationships between cities and Internet, are still neither achieving the attention it deserves, nor delivering the quality of empirical research it demands. This paper aims to fill the gap. Firstly, it presents a literature review of communication networks and urban system and recent efforts to meastire their structure and performance. Secondly, this paper applies network analysis methods to evaluate Internet connectivity, focusing on the spatial structure and city accessibility of five major Internet backbones in China. The overall Internet infrastructure within China is illustrated in light of the calibration of basic graph-theoretic measures based on gross characteristics. The degree of connectivity of cities included in the networks is measured with the total accessibility matrix （T） and the Shimbel distance matrix （D）. The results reveal the construction of new accessibility of cities follows the traditional urban hierarchy. The three national network access points （NAPs） Beijing, Shanghai, and Guangzhou and several regional hub cities are near the top of the accessibility hierarchy. In addition, geographical location of cities plays an important role in the decision-making of infrastructure constructions. Finally, several new themes for further research are highlighted.