Oeo106010 Lte Eran3.0 Idle Mode Behavior Issue 1.00

8/16/2019 Oeo106010 Lte Eran3.0 Idle Mode Behavior Issue 1.00

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LTE eRAN3.0 Idle Mode Behavior









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.

















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 receivingsystem 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 PLMNsconsidered 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.





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 selectanother 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 theUSIM.









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.







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 maximumsynchronization 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 thecell.

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 - N ID

(2) , NID(1)

and NID(2) can be calculated by the physical cell ID-NID

cell.





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)



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 acell is evaluated for cell selection as a result of a periodic search for a higher priorityPLMN while camped normally in a VPLMN in SIB1

Pcompensation max (PMaximum allowed power – PUE MAX Output Power, 0), where PMaximum allowed power is sent inSIB1

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 whena cell is evaluated for cell selection as a result of a periodic search for a higher priorityPLMN while camped normally in a VPLMN in SIB1

http://d/LTE/eRAN2.2/lte/para/CellResel-QRxLevMin.html

http://d/LTE/eRAN2.2/lte/para/CellResel-QQualMin.html

http://d/LTE/eRAN2.2/lte/para/CellResel-QQualMin.html

http://d/LTE/eRAN2.2/lte/para/CellResel-QRxLevMin.html





Following are the description of each parameters:

Parameter ID Description

QrxlevminIndicates the minimum required RX level. This parameter isused in the formula of the cell selection criterion S.

Qrxlevminoffset

Indicates the offset to the minimum required RX level. Thisvalue is included in criteria S and used in the evaluation ofcell selection. This parameter is valid only when the cellselection is triggered by periodic searches for higher-priorityPLMNs and the UE is served by a Visited Public Land MobileNetwork (VPLMN).

QqualminIndicates the minimum RX level of the cell. It is included incriteria S and used in the evaluation of cell selection.

QQualMinOffsetCfgInd Indicates whether to set the offset to the minimum requiredRX qulity for the cell. If this parameter is set to CFG, theoffset is required. If this parameter is set to NOT_CFG, theoffset does not need to be set.

QQualMinOffset Indicates the offset to the minimum required RX quality forthe cell. It is included in criteria S and used in the evaluationof cell selection. This parameter is required only when thecell selection is triggered by periodic searches for higher-

priority PLMNs and the UE is served by a Visited Public LandMobile Network (VPLMN).






PMaxCfgInd

Indicates whether to configure the the maximum TX power of the

UE in the intra-frequency neighboring cell. Recommended value isNOT_CFG

PMaxIndicates the maximum TX power of the UE in the cell. If thisparameter is not included in the SIB3, the UE uses the maximum TXpower.





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 andquality 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 toNOT_CFG. The value NOT_CFG indicates that the intra-frequency measurement

triggering threshold does not need to be set.



http://d/LTE/eRAN2.2/lte/para/CellResel-SIntraSearch.html

http://d/LTE/eRAN2.2/lte/para/CellResel-SIntraSearchQ.html



http://d/LTE/eRAN2.2/lte/para/CellResel-SIntraSearchCfgInd.html

http://d/LTE/eRAN2.2/lte/para/CellResel-SIntraSearchCfgInd.html








Frequencies of different RATs must have different priorities.

The priorities of E-UTRAN frequencies and inter-RAT frequencies are classified into thefollowing 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 orT320ForOther, whichis 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.








CellReselPrio

Indicates the cell reselection priority of the serving frequency. 0

indicates the lowest priority. This parameter is the networkingplanning parameter and needs to be planned in all frequency layers.






CellReselPriorityInd

Indicates whether to set the priority of the EUTRAN frequency for

inter-frequency cell reselection. This switch is not configured bydefault.

CellReselPriority

Indicates the priority of the EARFCN for inter-frequency cellreselection. The value 0 indicates the lowest priority. If thisparameter is not set, the lowest priority applies by default. Thisparameter is contained in SIB5. This priority is not configured bydefault.










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) retainvalid. 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 measurethem 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.








SNonIntraSearchCfg

Ind

Indicates whether to configure the measurement triggering

threshold of the inter-frequency/inter-RAT cell reselection.

SNonIntraSearchIndicates the measurement triggering threshold for the reselectionof the inter-frequency/inter-RAT cell.

QRxLevMinIndicates the minimum required receive level used in intra-frequencyE-UTRA cell reselection.

SIntraSearchCfgIndIndicates whether to configure the measurement triggeringthreshold of the intra-frequency cell reselection.

SIntraSearchIndicates the measurement triggering threshold for reselection tointra-frequency cells. The step is 2 dB.






SIntraSearchQIndicates the RSRQ threshold for starting intra-frequencymeasurements. It determines the probability of triggering cellreselection to an intra-frequency neighboring cell.

SNonIntraSearchQIndicates the RSRQ threshold for starting inter-frequency or inter-RAT measurements. It determines the probability of triggering cellreselection 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 inunits 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 othercells on the same frequency as candidates for reselection for a maximum of 300 seconds.








Qhyst

Indicates the hysteresis to the RSRP of the serving cell used in the

evaluation of cell reselection. The setting of this parameter isrelevant to the slow fading characteristic of the cell. That is, thegreater the variance of slow fading is, the larger the value of thehysteresis should be. Thus, the edge of the serving cell becomeslarger, and the neighboring cell becomes harder to be selected.






CellQoffset

(MODEUTRANINTRAFREQNCELL)

Indicates the cell specific offset between the serving cell and

the intra-frequency neighboring cell that is related totriggering of cell reselection. The larger the value of thisparameter is, the less possibly the cell reselection occurs. Thisparameter is contained in SIB4.

CellQoffset

(MODEUTRANINTERFREQNCELL)

Indicates the cell specific offset between the serving cell andthe inter-frequency neighboring cell that is related totriggering of cell reselection. The larger the value of thisparameter is, the less possibly the cell reselection occurs. Thisparameter 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.





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.


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.






Command for trigger Rx quality criteria

Command for threshed (EUTRAN)

Command for threshold (UMTS)

Command for threshold (GSM)









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.





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.





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 isscheduled 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.





The scheduling periods of other SIBs are determined by the SibxPeriod (x = 2, 3, …, 8)

parameter.









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 eNodeBtransmits 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 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.








ModifyPeriodCoeff

(MOD BCCHCFG)

Indicates the modification period coefficient for the BCCH.ModifyPeriod = ModifyPeriodCoeff x defaultPagingCycle, whereModifyPeriod means the BCCH modification period (unit: radio

frame), ModifyPeriodCoeff means the modification periodcoefficient for the BCCH, and defaultPagingCycle means thedefault paging cycle (unit: radio frame).

DefaultPagingCycle

(MOD PCCHCFG)

Indicates the default paging period. It is also called DRX period. Ifthe EPC specifies the DRX period, this parameter is compared withthe DRX period specified by the EPC. The UE uses the smaller one

between the two DRX periods. If the EPC does not specify the DRXperiod, 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.

















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







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:










DefaultPagingCycle

Indicates the default paging period. It is also called DRX period. Ifthe EPC specifies the DRX period, this parameter is compared withthe DRX period specified by the EPC. The UE uses the smaller one

between the two DRX periods. If the EPC does not specify the DRXperiod, the period is specified by this parameter, whose value isdelivered 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.




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Oeo106010 Lte Eran3.0 Idle Mode Behavior Issue 1.00