In current systems such as, e.g., the UMTS Terrestrial Radio Access Network (UTRAN) the reception bandwidth of user equipments (UEs) is the same as the cell transmission bandwidth. However, in Evolved UTRAN (E-UTRAN) the system may employ variable bandwidths. Further, the minimum bandwidth that is applied by a user equipment can be smaller than the network bandwidth. For instance, a typical case in future releases of E-UTRAN would be a 20 MHz user equipment operating in a system comprising a 30 MHz or 40 MHz cell transmission bandwidth. One additional important aspect of E-UTRAN is the potentially very large number of active and idle mode users per cell. This is partly due to the possibly large bandwidth that can be applied (10 MHz and 20 MHz cases) and partly because of the packet-oriented design. Hence, the number of paging messages per cell is envisioned to be much larger compared to previous radio access networks, e.g. the UTRAN or GERAN system, and, as a consequence, paging in E-UTRAN may consume more resources than in other systems.
In E-UTRAN, no radio resources are allocated to a user equipment in idle mode and, thus, there is no RRC connection maintained (see, e.g., the documents 3GPP TS25.304, “UE procedures in idle mode and procedures for cell reselection in connected mode” and 3GPP TS25.331, “Radio Resource Control Protocol Specifications” issued by the 3rd Generation Partnership Project). Therefore, the user equipment is informed about an incoming call by help of a paging indication. In case of an incoming call the network can page the user equipment, whereby the information relates to the call only at a well-defined instance, i.e. once per DRX cycle. This implies that user equipments need to monitor the paging indication once per DRX cycle. As E-UTRAN fully employs packet switching technology, it requires efficient paging mechanisms since the packet arrival (i.e. incoming calls) is bursty.
According to current solutions the paging is sent in the centre of the transmission bandwidth. This solution works well for user equipments having a bandwidth that is the same as the cell transmission bandwidth. However, in some E-UTRAN scenarios the bandwidth of the user equipment is smaller than the network bandwidth. For such scenarios a user equipment must retune its receiver each time it needs to listen to the paging. Further, current solutions also lead to less flexibility in terms of resource allocation from the network perspective.
USPTO Backgrounds
USPTO Backgrounds