Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular technology for networks based on the Global system For Mobile (GSM) standard. The UMTS is developed by the 3rd Generation Partnership Project (3GPP). UMTS employs Wideband Code Division Multiple Access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators. UMTS specifies a complete network system covering the UMTS Radio Access Network (UTRAN), the core network (Mobile Application Part (MAP)), and the authentication of users via Subscriber Identity Module (SIM) cards.
The User Equipment (UE) in the UMTS air interface has several activity states such as, for example, a Dedicated Transport Channel (Cell_DCH) state, a Forward Access Channel (Cell_FACH) state, a Paging Channel (Cell_PCH) state, a UTRAN registration area (URA_PCH) state, and idle mode. In a Cell-DCH state, a dedicated physical channel is allocated to the UE in uplink and downlink transmission. In a Cell_FACH state, no dedicated physical channel is allocated to UE. The UE continuously monitors a FACH in the downlink transmission. The UE is assigned a default common or shared transport channel in the uplink that the UE can use anytime according to the access procedure for the corresponding transport channel. In the Cell_PCH state, no dedicated physical channel is allocated to the UE, and no uplink transmission is possible. The position of the UE is known by UTRAN on a cell level according to the cell in which the UE most recently performed a cell update procedure. In the URA_PCH state, no dedicated channel is allocated to the UE and no uplink transmission is possible. The location of the UE is known on a UTRAN registration area level according to the URA assigned to the UE during the last performed URA update procedure.
Power consumption is a major issue in the UE. The amount of the power consumption in the UE depends on the UE's current activity which further depends on the current state of the UE. In terms of Radio Resource Control (RRC) states, when the UE is in the Cell-DCH state, the UE consumes maximum power and the power consumption reduces as the UE transitions to the Cell_FACH state, the Cell_PCH state, the URA_PCH state, and an idle mode in the same order. The RRC protocol belongs to the UMTS Wideband Code Division Multiple Access (WCDMA) protocol stack and handles the control plane signalling of Layer 3 between the UE and the UTRAN. Whenever the UE completes data transfer or does not have any more User Packet Switch data (PS data) to transmit for certain duration of time, maintaining the UE in idle mode is advisable. The idle mode is the most efficient battery consumption state for the UE.
According to the related art, fast dormancy is the process which helps UE to reach the dormant state as early as possible. The final intention of fast dormancy is to transition the UE into idle mode as soon as possible. Fast dormancy applies only for Packet Switched (PS) data and does not apply for Circuit Switched (CS) data or when CS related Non Stratum Access (NAS) procedures are on-going where NAS is a functional layer in the UMTS wireless telecom protocol stack between a core network and UE. Methods according to the related art achieve fast dormancy, where UE sends the Signalling Connection Release Indication (SCRI) message with cause defined for fast dormancy according to specification 25.331 of 3GPP, to UTRAN to provide an indication of the UE's dormant state. As provided by 3GPP specification, transitioning the UE to idle mode is easier when the UE is in the Cell_DCH state or the Cell_FACH state as compared to the Cell_PCH state or the URA_PCH state. If the UE is in the Cell_PCH state or the URA_PCH state, methods according to the related art follow complicated procedures to achieve fast dormancy. These procedures have an overhead of signalling messages between UE and UTRAN. Further, such procedures require allocation, release of resources on UTRAN side and require configuration, release of resources, and channels on the UE side. Thus, the above steps result in more number of intermediate state transitions, more number of signaling message exchanges making the existing methods time and energy inefficient.
Due to above mentioned reasons, existing methods fail to achieve fast dormancy with reduced signalling between UE and UTRAN faster in case when UE is in the Cell_PCH state or the URA_PCH state.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.