An increasingly wireless world will mean that devices with multiple network interfaces will soon become commonplace. Users will expect to be always connected from anywhere and at any time as connections will be switched to available networks using handover techniques. However, different networks have different Qualities-of-Service so a Quality-of-Service Framework is needed to help applications and services deal with this new environment. In addition, since these networks must work together, future mobile systems will have an open, instead of the currently closed, architecture. Therefore new mechanisms will be needed to protect users, servers and network infrastructure. This means that future mobile networks will have to integrate communications, mobility, quality-of service and security. This paper provides an overview of potential architectures for communication in future networks. Our study shows that only a number of these architectures support this integration.