1.Oeo106010 Lte Eran3.0 Idle Mode Behavior Issue 1
-
Upload
elaine-tan-diaz -
Category
Documents
-
view
172 -
download
3
description
Transcript of 1.Oeo106010 Lte Eran3.0 Idle Mode Behavior Issue 1
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� PLMN selection
Used to ensure that the PLMN selected by the UE provides services properly.
� System information reception
The network broadcasts the network information to the UE that camps on the cell.
Upon reception of broadcast information, the UE obtains the network information and
takes actions accordingly.
� Cell selection and reselection
Used to ensure that the UE finds a suitable cell to camp on.
� Location registration
This procedure is used by the UE to report its status to the network. This procedure is
of two types: periodical location registration and the location registration necessitated
by changes in the location area.
� Paging procedure
Used for the network to send paging messages to a UE which is in idle mode,
CELL_PCH state, or URA_PCH state.
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� The UE that is powered on but does not have an RRC connection to the radio network
is considered to be in idle mode. Idle mode management is controlled by some
system messages broadcasting by eNodeB , ensure that UE can get a better service
from the suitable cell, including the following procedure:
� PLMN selection: The UE selects a Public Land Mobile Network (PLMN) and
registers on the PLMN.
� Cell selection: The UE selects a cell in the chosen PLMN and camps on the
cell so that the UE can monitor system information and paging messages to
obtain service.
� Cell reselection: When camped on a cell, a UE regularly searches for a better
cell according to the cell reselection criteria, for the purpose of correctly
receiving system information and successfully initiating services.
� Tracking Area (TA) registration: The UE registers its location with the Evolved
Packet Core (EPC) through a TA registration procedure so that the EPC can
page the UE within the TA and request the UE to initiate services.
� PLMN identity consists of a Mobile Country Code (MCC) and a Mobile Network Code
(MNC).
� When a UE is powered on or recovers from lack of coverage, after the cell search, the
UE first selects the last registered PLMN and attempts to register on that PLMN. If the
registration on the PLMN is successful, the UE shows the selected PLMN on the
display, and now it can obtain service from an operator. If the last registered PLMN is
unavailable or the registration on the PLMN fails, another PLMN can be automatically
or manually selected according to the priorities of PLMNs stored in the USIM.
� Several PLMN concepts are defined:
� Equivalent PLMN List:The Equivalent PLMN (EPLMN) list is a list of PLMNs
considered as equivalent to the local network by the UE in terms of service
provisioning. During PLMN selection, the UE preferentially selects a PLMN
from the list. The EPLMN list is sent from the EPC and stored in the UE.
� Home PLMN: The Home PLMN (HPLMN) is the PLMN in which the UE is
defined. Each UE belongs to only one HPLMN.
� Visited PLMN: The Visited PLMN (VPLMN) is the PLMN where the UE is
located. A VPLMN can be the HPLMN.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� PLMN Selection in Automatic Mode
� When a UE fails to register on its last registered PLMN, the UE attempts to
select another PLMN. In automatic network selection mode, the UE selects a
PLMN in the following order:
� HPLMN or an EHPLMN
� Each PLMN in the "User Controlled PLMN Selector with Access
Technology" data file in the USIM, in order of priority, according to the
UE's support for Radio Access Technologies (RATs)
� Other PLMNs with signals of high received quality, in a random order.
The high quality of signals is defined as the Reference Signal Received
Power (RSRP) of a cell in the PLMN being greater than or equal to -
110 dBm.
� Other PLMNs in order of decreasing signal quality
� When the UE finds a suitable cell in a PLMN during the preceding procedure,
the UE attempts to register on the PLMN. If the registration is successful, the
UE camps on the suitable cell; otherwise, the UE tries the next PLMN.
� If the registration on none of the PLMNs is successful, the UE enters the
limited service state. If no PLMN is available, the UE cannot obtain any service.
� PLMN Selection in Manual Mode
� When a UE fails to register on its last registered PLMN, the UE attempts to
select another PLMN. In manual network selection mode, the UE displays a
list of PLMNs, in the same order as the PLMNs to be selected in automatic
network selection mode.
� In manual mode, the UE can also try forbidden PLMNs. If the UE succeeds in
registering on the selected PLMN, the PLMN is no more a forbidden PLMN to
the UE. The forbidden PLMNs are determined by the EPC.
� Roaming
� When in roaming state, a UE obtains service from a VPLMN that is different
from its HPLMN. For example, the UE obtains service from a PLMN in another
country (that is, from an international roaming area). When the UE with the
roaming service moves out of the coverage area of its HPLMN, the UE can
obtain service from another PLMN according to the PLMN information stored
in the USIM. The operator determines whether roaming is allowed for a UE.
� After the UE registers on a VPLMN by roaming, it periodically searches for its
HPLMN and attempts to return to the HPLMN. The time interval between
consecutive searches for the HPLMN is defined by the operator and stored in
the USIM.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� After selecting a PLMN, a UE selects a cell in the PLMN to camp on. When camped
on the cell, the UE monitors system information, performs measurements on the
serving cell and neighboring cells, and selects a better cell to camp on, according to
measurement rules and cell reselection criteria.
� UE performs this procedure according to the selection or reselection related
parameters in the system information or in the RRC Connection Release message.
� A UE can use one of the following two cell selection procedures: Stored Information
Cell Selection and Initial Cell Selection. The Stored Information Cell Selection
procedure takes precedence over the Initial Cell Selection procedure. The UE uses
the latter procedure only when it fails to find a suitable cell by using the former
procedure.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� Cell search is a procedure in which a UE achieves time and frequency
synchronization with a cell, obtains the physical cell ID, and learns the signal quality
and other information about the cell based on the physical cell ID. Before PLMN
selection, a UE performs a cell search on all carrier frequencies.
� By monitoring the synchronization signal, UE gets the frame synchronization, and
then, UE can measure the reference signal and read the BCH.
� The cell search procedure is as follows:
� The UE listens to the P-SS to achieve clock synchronization with a maximum
synchronization error of 5 ms. Physical cell IDs have a one-to-one
correspondence with primary synchronization signals. Therefore, the UE
acquires the physical cell ID by monitoring the P-SS
� The UE listens to the S-SS to achieve frame synchronization, that is, time
synchronization with the cell. Cell ID groups have a one-to-one relation with
secondary synchronization signals. Therefore, the UE acquires the number of
the cell ID group to which the physical cell ID belongs by monitoring the S-SS.
� The UE listens to the downlink reference signal to acquire the signal quality in
the cell.
� The UE listens to the Broadcast Channel (BCH) to acquire other information
about the cell.
� The P-SS and S-SS of a cell is determained by the site ID - NID(1) and sector ID - NID
(2) ,
NID(1) and NID
(2) can be calculated by the physical cell ID-NIDcell.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� A UE considers an E-UTRAN cell as a suitable cell only when the measured RSRP
and reference signal received quality (RSRQ) values of the cell are greater than the
receive (RX) level threshold (Qrxlevmin) and the RX signal quality threshold
(QQualMin) for the cell, respectively.
� An E-UTRAN cell becomes a suitable cell when both the following conditions are met:
� Srxlev > 0 Squal > 0
� Srxlev = Qrxlevmeas - (Qrxlevmin + Qrxlevminoffset) – Pcompensation
� Squal = Qqualmeas - (QQualMin + QQualMinOffset)
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
Parameter Description
Qrxlevmeas Measured RSRP value
Qrxlevmin Minimal Required Rx level (dBm) in SIB1
Qrxlevminoffset
Offset to Srxlev, relative with PLMN priority ,.QrxlevminOffset is only applied when a cell is evaluated for cell selection as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN in SIB1
Pcompensation
max (PMaximum allowed power – PUE MAX Output Power, 0), where PMaximum allowed power is sent in SIB1
Qqualmeas measured RX signal quality (RSRQ value) of the cell, expressed in units of dB.
Qqualmin Minimal required signal quality
QQualMinOffset Offset to Qqualmin, relative with PLMN priority ,.QrxlevminOffset is only applied when a cell is evaluated for cell selection as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN in SIB1
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� Following are the description of each parameters:
Parameter ID Description
QrxlevminIndicates the minimum required RX level. This parameter is used in the formula of the cell selection criterion S.
Qrxlevminoffset
Indicates the offset to the minimum required RX level. This value is included in criteria S and used in the evaluation of cell selection. This parameter is valid only when the cell selection is triggered by periodic searches for higher-priority PLMNs and the UE is served by a Visited Public Land Mobile Network (VPLMN).
QqualminIndicates the minimum RX level of the cell. It is included in criteria S and used in the evaluation of cell selection.
QQualMinOffsetCfgInd Indicates whether to set the offset to the minimum required RX qulity for the cell. If this parameter is set to CFG, the offset is required. If this parameter is set to NOT_CFG, the offset does not need to be set.
QQualMinOffset Indicates the offset to the minimum required RX quality for the cell. It is included in criteria S and used in the evaluation of cell selection. This parameter is required only when the cell selection is triggered by periodic searches for higher-priority PLMNs and the UE is served by a Visited Public Land Mobile Network (VPLMN).
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
PMaxCfgIndIndicates whether to configure the the maximum TX power of the UE in the intra-frequency neighboring cell. Recommended value is NOT_CFG
PMaxIndicates the maximum TX power of the UE in the cell. If this parameter is not included in the SIB3, the UE uses the maximum TX power.
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� UE cell reselection include two steps:
� Start the measurement for the neighboring cells
� Rank the measured cells based on radio signal quality and priorities.
� To trigger intra-frequency measurements, the following rules apply:
� The UE does not perform intra-frequency measurements if the RX signal level
and quality of the serving cell are good, that is, the Srxlev and Squal values of
the serving cell are greater than the RSRP-based triggering threshold for intra-
frequency measurements (SIntraSearch) and the RSRQ-based triggering
threshold for intra-frequency measurements (SIntraSearchQ), respectively.
� The UE starts intra-frequency measurements if the Srxlev or Squal value of the
serving cell is not greater than SIntraSearch or SIntraSearchQ, respectively.
� The UE performs intra-frequency measurements regardless of the RX signal
level or quality of the serving cell if the SIntraSearchCfgInd parameter is set
to NOT_CFG. The value NOT_CFG indicates that the intra-frequency
measurement triggering threshold does not need to be set.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� Frequencies of different RATs must have different priorities.
� The priorities of E-UTRAN frequencies and inter-RAT frequencies are classified into
the following types:
� Absolute priority: This priority is specified by the CellReselPriority parameter
and is sent to UEs through broadcast of system information.
� Dedicated priority: This priority is UE-specific. Dedicated priorities are
generated by the internal dedicated prioritization algorithm or generated based
on a Subscriber Profile ID (SPID) when a UE releases radio resources. They
are sent to the UE through the RRC Connection Release message. The
validity time of dedicated priorities is defined by the timer
T320ForLoadBalance or T320ForOther, which is sent to the UE through the
RRC Connection Release message.
� During cell reselection, when a UE is camped on a suitable cell, the UE ignores all the
absolute priorities provided in system information if dedicated priorities are assigned
through dedicated signaling. If the UE acquires the priorities of other frequencies but
no priority of the serving frequency, the UE regards the priority of the serving
frequency as the lowest.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
CellReselPrioIndicates the cell reselection priority of the serving frequency. 0 indicates the lowest priority. This parameter is the networking planning parameter and needs to be planned in all frequency layers.
LTE eRAN2.2 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
CellReselPriorityIndIndicates whether to set the priority of the EUTRAN frequency for inter-frequency cell reselection. This switch is not configured by default.
CellReselPriority
Indicates the priority of the EARFCN for inter-frequency cell reselection. The value 0 indicates the lowest priority. If this parameter is not set, the lowest priority applies by default. This parameter is contained in SIB5. This priority is not configured by default.
LTE eRAN2.2 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
T320ForLoadBalance
Indicates the length of timer T320 that is configured in
the case of load balancing. It refers to the time period during which
the dedicated priorities (used for cell reselection) retain valid.
The time period is contained in the RRCConnectionRelease message that
is received by the UE. After the timer specified in the
RRCConnectionRelease
message expires, the dedicated priorities become invalid.
T320ForOther
Indicates the length of timer T320 that is configured in
the case of load imbalancing. It refers to the time period during
which the dedicated priorities (used for cell reselection) retain
valid. The time period is contained in the RRCConnectionRelease message
that is received by the UE. After the timer specified in the
RRCConnectionRelease
message expires, the dedicated priorities become invalid.
� From SIB ,UE can get the serving cell and inter frequency/RAT neighbors’ priorities.
� For the high priority cells, UE measure them always, for the low priority cells, UE
measure them in case of the serving cell signal is lower than the threshold.
� The intra frequency cells have the same frequency priority, frequencies of different
RATs must have different priorities.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
SNonIntraSearchCfgInd
Indicates whether to configure the measurement triggering threshold of the inter-frequency/inter-RAT cell reselection.
SNonIntraSearchIndicates the measurement triggering threshold for the reselection of the inter-frequency/inter-RAT cell.
QRxLevMinIndicates the minimum required receive level used in intra-frequency E-UTRA cell reselection.
SIntraSearchCfgIndIndicates whether to configure the measurement triggering threshold of the intra-frequency cell reselection.
SIntraSearchIndicates the measurement triggering threshold for reselection to intra-frequency cells. The step is 2 dB.
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
SIntraSearchQIndicates the RSRQ threshold for starting intra-frequency measurements. It determines the probability of triggering cell reselection to an intra-frequency neighboring cell.
SNonIntraSearchQIndicates the RSRQ threshold for starting inter-frequency or inter-RAT measurements. It determines the probability of triggering cell reselection to an inter-frequency or inter-RAT neighboring cell.
� A UE makes a cell reselection decision according to cell reselection criteria. When making a
decision on reselection to an intra frequency or equal-priority inter frequency cell, the UE
checks whether the signal quality of a neighboring cell is higher than that of the serving cell.
� The cell-ranking criteria R_s for the serving cell and R_n for neighboring cells are defined as
follows:
� R_s = Qmeas,s + Qhyst
� R_n = Qmeas,n - CellQoffset
Where:
� Qmeas_s is the measured RSRP of the serving cell, expressed in units of dBm
� Qhyst is the hysteresis for the serving cell used in the ranking criteria, expressed in
units of dB.
� Qmeas_n is the measured RSRP of the neighboring cell, expressed in units of dBm
� CellQoffset is the offset for the neighboring cell used in the ranking criteria, expressed
in units of dB
� According to the cell reselection criteria, the UE should reselect the new cell only if both the
following conditions are met:
� The new cell is ranked higher than the serving cell during the cell reselection time.
� More than one second has elapsed since the UE camped on the serving cell.
� During cell reselection, the UE needs to check whether access to that cell is allowed according
to the cellAccessRelatedInfo Information Element (IE) in the SIB1. If the cell is barred, it must
be excluded from the candidate list, and the UE does not consider the cell as a candidate for
cell reselection. If the cell is unsuitable because it is part of the list of forbidden TAs for roaming
or it does not belong to the registered PLMN or an EPLMN, the UE does not consider this cell
and other cells on the same frequency as candidates for reselection for a maximum of 300
seconds.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
Qhyst
Indicates the hysteresis to the RSRP of the serving cell used in the evaluation of cell reselection. The setting of this parameter is relevant to the slow fading characteristic of the cell. That is, the greater the variance of slow fading is, the larger the value of the hysteresis should be. Thus, the edge of the serving cell becomes larger, and the neighboring cell becomes harder to be selected.
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
CellQoffset
(MOD EUTRANINTRAFREQNCELL)
Indicates the cell specific offset between the serving cell and the intra-frequency neighboring cell that is related to triggering of cell reselection. The larger the value of this parameter is, the less possibly the cell reselection occurs. This parameter is contained in SIB4.
CellQoffset
(MOD EUTRANINTERFREQNCELL)
Indicates the cell specific offset between the serving cell and the inter-frequency neighboring cell that is related to triggering of cell reselection. The larger the value of this parameter is, the less possibly the cell reselection occurs. This parameter is contained in SIB5.
� If SIB3 contains the value of ThrshServLowQ, a UE performs reselection to a higher-priority
inter-frequency or inter-RAT neighboring cell when both the following conditions are met:
� The neighboring cell has one of the following measurement results:
� The Squal value of the evaluated neighboring E-UTRAN or UTRAN cell is
always greater than the RX signal quality threshold used in reselection to
higher-priority cells (ThreshXHighQ) during the cell reselection time specified
by the TReselEutran or TReselUtran parameter.
� The Srxlev value of the evaluated neighboring GERAN or CDMA2000 cell is
always greater than the RX signal level threshold used in reselection to higher-
priority cells (ThreshXHigh) during the cell reselection time specified by the
TReselGeran or Cdma1XrttTreselection parameter
� The UE has camped on the serving cell for more than 1 second.
� If SIB3 does not contain the value of ThrshServLowQ, a UE performs reselection to a higher-
priority inter-frequency or inter-RAT neighboring cell when the following conditions are both
met:
� The Srxlev value of the evaluated neighboring cell is always greater than the
ThreshXHigh value during the predefined cell reselection time
� The UE has camped on the serving cell for more than 1 second
� If the highest ranked cell is unsuitable for a UE because it is included in a roaming-forbidden
TA or because it does not belong to the RPLMN or an EPLMN, the UE does not consider this
cell as a candidate for reselection for a maximum of 300 seconds.
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� If SIB3 contains the value of ThrshServLowQ, a UE performs reselection to a lower-priority
inter-frequency or inter-RAT neighboring cell when all the following conditions are met:
� No cell meets the criteria for reselection to higher-priority cells
� The Squal value of the serving cell is always less than the RX signal quality threshold
for the serving cell used in reselection to lower-priority cells (ThrshServLowQ) during
the predefined cell reselection time.
� The neighboring cell has one of the following measurement results:
� The Squal value of the evaluated neighboring E-UTRAN or UTRAN cell is
always greater than the RX signal quality threshold used in reselection to
lower-priority cells (ThreshXLowQ) during the predefined cell reselection time.
� The Srxlev value of the evaluated neighboring GERAN or CDMA2000 cell is
always greater than the RX signal level threshold used in reselection to lower-
priority cells (ThreshXLowQ) during the predefined cell reselection time.
� The UE has camped on the serving cell for more than 1 second
� If SIB3 does not contain the value of ThrshServLowQ, a UE performs reselection to a lower-
priority inter-frequency or inter-RAT cell when all the following conditions are met:
� No cell meets the criteria for reselection to higher-priority cells
� The Srxlev value of the serving cell is always less than the RX signal level threshold for
the serving frequency used in reselection to lower-priority cells (ThrshServLow)
during the predefined
� The Srxlev value of the evaluated neighboring cell is always greater than the threshold
used in reselection to lower-priority cells (ThreshXLow) during the predefined cell
reselection time cell reselection time.
� The UE has camped on the serving cell for more than 1 second
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� Command for trigger Rx quality criteria
� Command for threshed (EUTRAN)
� Command for threshold (UMTS)
� Command for threshold (GSM)
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
� Based on the contents of the System Information (SI) messages, SI is divided into one
Master Information Block (MIB) and 11 System Information Blocks (SIBs). SI
messages are transmitted over the BCCH.
� The scheduling period and transport format of the MIB is predefined ,therefore, the UE
receives the MIB on the BCH without obtaining other information on the network.
� The SIB1 is transmitted over the Downlink Shared Channel (DL-SCH), the scheduling
period of the SIB1 is 80 ms.
� The SIB1 carries the scheduling period information of other SIBs.
� Other SIBs are transmitted over the DL-SCH also, and the scheduling periods can be
separately set. The SIBs with the same scheduling period can be transmitted
together.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� The MIB is transmitted over the BCH. The scheduling period of the MIB is 40 ms. The
first transmission of the MIB is scheduled in subframe 0 of radio frames for which the
SFN mod 4 = 0, and repetitions are scheduled in subframe 0 of the last three radio
frames in each period.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� SIB1 is mandatory SIB and send in DL-SCH
� The scheduling period of the SIB1 is fixed to 80 ms. The first transmission of the SIB1
is scheduled in subframe 5 of radio frames for which the SFN mod 8 = 0, and
repetitions are scheduled in subframe 5 of the later radio frames for which SFN mod 2
= 0 in each period.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� The scheduling periods of other SIBs are determined by the SibxPeriod (x = 2, 3, …,
8) parameter.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� After obtaining the SI message properly, the UE does not read the message
repeatedly. It updates the SI message only in the following scenarios:
� The UE receives the SI message change notification in the paging message
transmitted from the eNodeB.
� The UE receives the ETWS (ETWS: Earthquake and Tsunami Warning
System) message broadcast notification in the paging message transmitted
from the eNodeB.
� The UE receives the SI message 3 hours after receiving an SI message.
� The modification period of the SI message is N radio frames, and the period starts
from radio frames for which SFN mod n = 0. During the n modification period, the
eNodeB transmits the paging message to inform UEs in RRC_IDLE mode and UEs in
RRC_CONNECTED mode about the SI message change when a paging cycle
arrives. When the n+1 modification period arrives, the eNodeB transmits the updated
SI message.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� The modification period of the SI message is N radio frames, and the period starts
from radio frames for which SFN mod n = 0. During the n modification period, the
eNodeB transmits the paging message to inform UEs in RRC_IDLE mode and UEs in
RRC_CONNECTED mode about the SI message change when a paging cycle
arrives. When the n+1 modification period arrives, the eNodeB transmits the updated
SI message.
� The length of the SI modification period n = ModifyPeriodCoeff x
DefaultPagingCycle
� where:
� ModifyPeriodCoeff is the coefficient of the modification period, indicating the
minimum number of interceptions on the paging messages for the UE in the SI
message modification period.
� DefaultPagingCycle is the default paging cycle in the unit of radio frames.
� ModifyPeriodCoeff and DefaultPagingCycle are broadcast in the SIB2.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
ModifyPeriodCoeff
(MOD BCCHCFG)
Indicates the modification period coefficient for the BCCH. ModifyPeriod = ModifyPeriodCoeff x defaultPagingCycle, where ModifyPeriod means the BCCH modification period (unit: radio frame), ModifyPeriodCoeff means the modification period coefficient for the BCCH, and defaultPagingCycle means the default paging cycle (unit: radio frame).
DefaultPagingCycle
(MOD PCCHCFG)
Indicates the default paging period. It is also called DRX period. If the EPC specifies the DRX period, this parameter is compared with the DRX period specified by the EPC. The UE uses the smaller one between the two DRX periods. If the EPC does not specify the DRX period, the period is specified by this parameter, whose value is delivered to the UE with the system information.
� The TA is a concept introduced to the LTE/SAE system for location management of
UEs. The EPC sends paging messages to all eNodeBs in the TA. A TA is identified by
a Tracking Area Identity (TAI), which consists of the MCC, MNC, and Tracking Area
Code (TAC).
� eNodeB broadcast the tracking area code by SIB1.
� A UE informs the EPC of its Tracking Area (TA) by TA registration. There are two
ways for the UE TA registration:
� Attach/Detach
� TA update
� When a UE needs to obtain service from a network but is not registered to the
network, the UE performs an Attach procedure for TA registration.
� After a successful Attach procedure, the UE is allocated an IP address. The Mobile
Equipment Identity (MEI) of the UE will be sent to the Mobility Management Entity
(MME) for authentication.
� When the UE fails to access the EPC or the EPC does not allow the access of the
UE, a Detach procedure is initiated. After the Detach procedure, the EPC no longer
pages the UE.
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� UEs in RRC_IDLE mode use DRX to receive paging messages in order to reduce power
consumption. The eNodeB may have to buffer the paging message until a UE’s paging
occasion occurs.
� The time positions of paging messages are fixed on the Uu interface, which are indicated by
the Paging Frames (PFs) and Paging Occasion (PO) subframes. One PF is one radio frame,
which may contain one or multiple Pos. One PO is a subframe where the Paging Radio
Network Temporary Identifier (P-RNTI) is contained. The PO is transmitted over the PDCCH.
UEs read paging messages over the Physical Downlink Shared Channel (PDSCH) according
to the P-RNTI.
� The PF number and PO subframe number can be calculated according to the IMSI of the UE,
DRX cycle, and number of PO subframes in a DRX cycle. Frame numbers are stored in the SI
related to the DRX parameters of the UE. When the DRX parameters change, PF number and
PO subframe number change accordingly.
� The SFN of a PF is derived from the following formula:
� SFN mod T = (T div N) x (UE_ID mod N)
� The subframe number i_s of a PO is derived from the following formula:
� i_s =Floor (UE_ID/N) mod Ns
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
NsPO when
i_s=0
PO when
i_s=1
PO when
i_s=2
PO when
i_s=3
1 0 N/A N/A N/A
2 0 5 N/A N/A
4 0 1 5 6
NsPO when
i_s=0
PO when
i_s=1
PO when
i_s=2
PO when
i_s=3
1 9 N/A N/A N/A
2 4 9 N/A N/A
4 0 4 5 9
FDD Subframe Patterns:
TDD Subframe Patterns
� For FDD and TDD, the PO subframe patterns are different, because for TDD mode,
some of the subframes are of uplink.
� The meaning of parameters is following:
� T is the length of a DRX cycle. It is determined by the shortest UE-specific
DRX cycle. The value of T can be either signaled from the NAS or specified by
the DefaultPagingCycle parameter. If the NAS indicates the DRX cycle, the
UE compares the value signaled from the NAS and the value of
DefaultPagingCycle and uses the smaller value between them. If the NAS
does not indicate the DRX cycle, the value of T is determined by the
DefaultPagingCycle parameter and sent to the UE through an SI message.
� N is min(T,NB). The NB parameter specifies the number of PO subframes in a
DRX cycle. Based on the actual configuration on the eNodeB, NB can be set
to 4T, 2T, T, T/2, T/4, T/8, T/16, or T/32.
� Ns is max(1,NB/T).
� UE_ID is IMSI mod 1024. If a UE without IMSI makes an emergency call, the
UE should use the default UE_ID value of 0.
� If NB is greater, more subframes are used for paging.
� Following are some FDD examples:
� Example1:
� Example2:
� Example3:
� Example4:
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
� In each DRX cycle, a UE monitors one P-RNTI transmitted on the PDCCH only in this
PO and reads the paging messages on the PDSCH. Different UEs may have the
same PO. If UEs are paged by the MME in the same PO, the paging records must be
combined into the same paging message in RRC layer . When certain UE-specific
paging and group paging triggered by change of an SI message occur
simultaneously, the paging messages must also be combined in RRC layer .
Confidential Information of Huawei. No Spreading Without
Permission
LTE eRAN3.0 Idle Mode Behavior
LTE eRAN3.0 Idle Mode Behavior
Confidential Information of Huawei. No Spreading Without
Permission
Parameter ID Description
DefaultPagingCycle
Indicates the default paging period. It is also called DRX period. If the EPC specifies the DRX period, this parameter is compared with the DRX period specified by the EPC. The UE uses the smaller one between the two DRX periods. If the EPC does not specify the DRX period, the period is specified by this parameter, whose value is delivered to the UE with the system information.
NBIndicates the number of paging occasions (in units of subframes), that is, the number of paging groups, within a paging cycle.