Quality of Service (QoS) provision will be one of the most challenging issues in the heterogeneous wireless networks. It is also anticipated that new services will emerge, mainlyfor real-time and multimedia applications, which will need high data rates. One of the main aims of the future heterogeneous wireless networks is to allow mobile users to roam between different wireless networks operators and geographical areas while providing interactive broadband multimedia services and seamless connectivity. This paper focuses on the performance analysis of 4G network architecture where roaming connections are handled in an effective manners. The analysis is based on generalised buffer sharing, as a cost-effective resource sharing protocol, in support of multiple voice calls, streaming media and data packet service classes.