宽带IP接入技术

随着社会科技的发展,通信网络正发生着深刻的变革,宽带化成了电信发展的必经之路。本文主要概述了宽带接入技术中数字用户线路、混合光纤同轴网这两个比较重要的主流技术,分析各自的优缺点。并着重阐述了ADSL,HFC这两个重要的技术。     

Wholesale market definition in telecommunications: The issue of wholesale broadband access

The scope of a wholesale market may, in addition to demand- and supply-side substitution at the wholesale level, also be determined by substitution patterns at the retail level. Considering wholesale broadband access markets, it is argued that each of these forces can be strong enough to render a 5–10% price increase by a hypothetical monopolist at the wholesale level unprofitable and thus may lead to a wider wholesale market definition including, for example, cable networks in addition to DSL. Based on the theory of derived demand elasticities the paper discusses under which circumstances this could be the case. The position of the European Commission and the practice of national regulatory authorities are then reviewed in light of these arguments.     

Spatial data constraints: Implications for measuring broadband

The accurate determination of where broadband telecommunication services are available in the United States continues to be a significant challenge. Existing data regarding broadband provision, such as that provided by the Federal Communication Commission (FCC) simply designate ZIP codes with at least one high-speed Internet subscriber. As ZIP code areas vary greatly in size and shape, the lack of geographic specificity as to exactly where broadband is available, particularly within ZIP code areas, confounds communications policymaking. Further, there are a number of additional geographic nuances concerning broadband availability that also inhibit empirical examination and policy generation, including the spatial limitations of digital subscriber line services. The purpose of this paper is to briefly review the issues concerning broadband measurement in the United States and provide an empirical analysis of several spatial data constraints that must be accounted for when interpreting and constructing public telecommunications policy.