Integration of multi-radio access in a beyond 3G network

A major aspect of Beyond 3G networks is the efficient integration of multiple radio access technologies in a common network. One advantage of this multi-radio access integration is the increase in radio resource efficiency, e.g. due to a larger trunking gain and reduced radio cost per link. This paper analyses and compares the different ways of how multi-radio access integration can be achieved. In particular, it investigates three multi-radio integration alternatives, two of them solving the problem at the network level and the third one on the link level. The comparison of the different approaches reveals that link level integration allows access path switching on a shorter time scale than network level integration. Another difference is where they allow the multi-radio resource management functions to take place, on network side or on user terminal side. In general, it is concluded that all schemes have certain advantages and disadvantages depending on the considered scenario. It is also highlighted, that these different integration schemes can be combined, i.e. some radio access technologies can be integrated on link level, while others can be integrated on network level.