Paging Calculation

IuX Utilization Calculation Huawei Network

Paging CalculationHuawei NetworkJuly 14th, 20138/27/[email protected] slide will depict how to calculate paging utilization in Huawei networkSimple paging description and paging cause will be discussed also this slideWhy paging utilization less than 100% but congestion already triggered can be check in this discussionCounter use for monitoring after LAC/RAC splitting and DT step should be taken will be listed in this slide

8/27/[email protected] is one of the most important procedures in WCDMA.Paging is critical factor associated with the call setup success rate of the network.The network will initiate paging in the following three cases:Mobile terminating callUTRAN system information updateUE state transitionsWhen receiving paging from core network, UTRAN decides the paging type.When mobile in IDLE mode, CELL PCH and URA PCH, UTRAN will send paging type 1 on PCCH. Paging type 2 for a UE in RRC Connected Mode (CELL_DCH and CELL_FACH states) on DCCH.When UE idle mode, paging will be broadcasted in to LAC area, when UE in CELL DCH, CELL PCH and CELL FACH, paging attempt will be sent to respective cell, while UE in URA state, paging will be broadcasted into URA area8/27/[email protected] MessagesThe paging message include:CN Domain Indicator, used by the RNC to identify from which domain the Paging message originatesPermanent NAS UE Identity (that is, IMSI) used for calculation of paging group and also for WCDMA RAN paging co-ordination.The paging message may also contain the following:The DRX Cycle Length Coefficient (if available) may be included in the Paging message, and if present, the WCDMA shall when applicable use it for calculating the paging occasions for the UE.Temporary UE ID (that is, the TMSI)Paging Area. Can be the Location Area Identity (LAI), the Routing Area Identity (RAI) and (if omitted) the whole RNCPaging cause

8/27/[email protected] Terminating CallAfter sending paging response, RRC connection request will be sent with establishment cause: terminating conversation call 8/27/[email protected]

UTRAN system information update When cell system information changed, paging type 1 is used to inform mobile to read the updated system information. It is special for the mobile in IDLE mode, CELL PCH and URA PCH .8/27/[email protected]

UE state transitions8/27/[email protected]

When UTRAN wants mobile to change its state from CELL PCH or URA PCH to CELL FACH, UTRAN will send paging type 1 to mobile.

Discontinuous Reception (DRX)The UE may use Discontinuous Reception (DRX) in order to reduce power consumption. When DRX is used the UE needs only to monitor one Page Indicator, PI, in one Paging Occasion per DRX cycle.In FDD mode, DRX cycle length = 2^k, k is DRX cycle length coefficient. The UE shall store each CN domain specific DRX cycle length for each CN domain the UE is attached to and use the shortest of those DRX cycle lengths. The CS CN specific DRX cycle length coefficient shall be updated locally in the UE using information given in system information.The PS CN specific DRX cycle length coefficient shall be updated after the negotiation between the UE and PS CN by NAS procedure.

8/27/[email protected] OccasionPaging Occasion ={(IMSI div K) mod (DRX cycle length div PBP)} * PBP + n * DRX cycle length + Frame Offset, Where n = 0,1,2 as long as SFN is below its maximum value. K is the number of SCCPCH bears the PCH.In FDD mode, Paging Occasion = IMSI mod 2K + n*2K8/27/[email protected]

Paging Indicator Channel (PICH)One PICH radio frame of length 10 ms consists of 300 bits (b0, b1, , b299). Of these, 288 bits (b0, b1, , b287) are used to carry paging indicators.In each PICH frame, Np paging indicators {P0, , PNp-1} are transmitted, where Np=18, 36, 72, or 144. The PI calculated by higher layers for use for a certain UE, is associated to the paging indicator Pq . PI = DRX index mod NP = (IMSI div 8192) mod NP

If a paging indicator in a certain frame is set to "1" it is an indication that UEs associated with this paging indicator and PI should read the corresponding frame of the associated S-CCPCH.

8/27/[email protected]

Paging Cycle Coefficient In the idle mode, the UE can receive the paging indication with DRX to reduce the power consumption. At this time, the UE needs to detect only one paging indication in a paging occasion within a DRX cycle. The DRX cycle length of UTRAN domain is obtained by substituting this parameter into the formula DRX cycle = 2K PBP frames. Where, K is [the paging cycle coefficient], and PBP is the paging block cycle coefficient (In the FDD mode, PBP = 1).Influence on the network performance: If this parameter is set too small, the UE will detect the paging channel frequently, and thus the battery is consumed fast; if it is set too big, the UE will react very slowly on the paging, it will also occur that the system repeats the UE paging, and the downlink interference will be increased.

8/27/[email protected] Indicator per Frame (Np) Np is the number of paging indicators per frame. The value range of this parameter is 18, 36, 72, or 144.Influence on the network performance: PI = DRX index mod NP = (IMSI div 8192) mod NP. All of the IMSIs is divided into Np groups. If this parameter is set too small, for one IMSI, the paged probability of this IMSI will increase and it will consume too much power. If this parameter is set too big, the paged probability will decrease. The bit number of each PI decrease too, and it requests high demodulation performance for UE8/27/[email protected] Paging Utilization

Paging Calculation

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