During the last few years, the mobile wireless industry has been spending considerable effort to enhance the technical characteristics of existing second generation systems in the goal of upgrading their service provision capabilities and of promoting effective integration with data transport networks (the GSM GPRS is an obvious paradigm). This line of action can be anticipated as a first step in the migration path towards 3G systems and has been adopted for two basic reasons: the first is that market demand for wireless data services is currently a small portion of the overall wireless service demand and the second is that the deployment of new technologies in large scale requires gross economical investments. This paper proposes a protocol architecture, a physical configuration and a set of functions for DECT cell clusters that provide access to ISDN transport networks. It also proposes a scheme for the incorporation of these clusters in the numbering and mobility support schemes of existing GSM networks.