Navigation Capabilities of Future Mobile Communication Systems - will Global Navigation Satellite Systems become obsolete ?

The third and fourth generation personal communication systems (PCS) are going to be based on spread spectrum techniques. This article intends to show, that the signal structures used by these systems are very similar to the ones used by GPS and proposed European satellite navigation systems and can be used for the purpose of user localization. Various methods for determining the user position within a PCS are described. Following the concept of hierarchical cellular communication, hierarchical navigation is proposed. The mutual benefits of a global satellite navigation system (GNSS) and a PCS are emphasized.