Tiered services/private system support for CDMA systems

For many years, several standards activities have been devoted to find solutions for CDMA tiered service/private systems capabilities. The initial approach studied was to apply an overlay/underlay architecture in which both the private system and the public system operate on the same frequency with independent set of resources. However, it was found that this approach was not possible because of RF issues. In this paper, a new approach is proposed which introduces the concept of user zones for offering tiered service capabilities in CDMA systems. This approach has been endorsed by the CDG (CDMA Development Group) and the TIA TR45.5 subcommittee. This solution was approved for inclusion in the cdma2000 (3G) air interface standards.