U e State Sta St ate Ha H Handling andli lin ng Ue
U e States States Ue
States in UTRAN, GERAN, E-UTRA • The following transitions are supported by the LTE: 3G
LTE
G SM GSM_Connected
CELL_DCH
Handover
E-UTRA RRC_CONNECTED
Handover GPRS Packet transfer mode
CELL_FACH CCO with optional NACC
CELL_PCH URA_PCH
Reselection Connection establishment/release
Connection establishment/release UTRA_Idle
CCO, Reselection
Reselection
E-UTRA RRC_IDLE
Connection establishment/release
Reselection CCO, Reselection
*CCO = Cell Change Order
GSM_Idle/GPRS Packet_Idle
Mobility Management States Definition of main EPS Mobility Management states • EMM-DEREGISTERED – The UE is not reachable by a MME. – UE context can still be stored in the UE and MME
• EMM-REGISTERED – – – –
UE enters to EMM-Registered with Attach or Tracking Area Update procedure procedur e The UE location is known with accuracy of the tracking area list UE has at least one active PDN connection After Detach procedure the state is changed to EMM-DEREGISTERED
EMM states in UE Detach Attach reject TAU Reject All Bearer Deactivated
EMM-DEREGISTERED
EMM-REGISTERED Attach accept
EMM states in MME Detach Attach reject TAU Reject All Bearer Deactivated
EMM-DEREGISTERED
EMM-REGISTERED Attach accept TAU Accept
Connection Management States Definition of EPS Connection Management states • ECM-IDLE si gnaling connection between UE and network exists. – UE is in ECM-IDLE state when no NAS signaling sh all perform: – In the EMM-REGISTERED and ECM-IDLE state, the UE shall
Tracking Area Update Periodic Tracking Area Update Service Request Answer to paging from MME with Service Request
– UE and MME enter the ECM-CONNECTED state when signaling connection is established.
• ECM-CONNECTED – UE location is known in the MME with an accuracy of a serving eNodeB. – For a UE in the ECM-CONNECTED state, there exists a signaling connection between the UE and the MME. bo th UE and MME from fr om ECM-CONNECTED ECM-CONNECTED to – The S1 release procedure changes the state at both ECM-IDLE.
ECM states in UE
ECM states in MME
RRC Released ECM-IDLE
ECM-CONNECTED RRC Established
S1 Released ECM-IDLE
ECM-CONNECTED S1 Established
Purpose of DRX
DRX/DTX – Gener DRX/DTX General al Motivation Motivation is the the Challeng Challenge e –> Battery Battery Capacity Increases only Slowly Compared to Moore’s Moore’s Law Joseph A. Paradiso Massachusetts Massachusetts Institute of Technology Media Media Laboratory, Laboratory, Thad Starner Georgia Institute of Technology, Technology, GVU Center “Energy “Energy Scavenging for Mobile and Wireless Electronics”, Electronics”, Pervasive Computing, Computing, IEEE Volume 4, Issue 1, Jan.-March 2005 2005 Page(s):18 Page(s):18 - 27 Digital Object Identifier 10.1109/MPRV.2005.9 10.1109/MPRV.2005.9
CPU by Moore’s law = double every 18 months
Battery savings are a must and are proportional to active/inactive ratio Battery capacity double every 12 years
Normal Norm al eNB eNB Initia Initiated ted Transiti ransition on to ECM-ID ECM-IDLE LE (e.g. due to user inactivity)
inactivityTimer Inactivity for UL & DL LNCEL; 10..65535s; 1s ; 30s
Main impact –> UE- consumes less battery battery power power in idle mode and there are less less active UEs which which network have to handle. Fast going to inactivity has drawback of longer connection setup time (transition idle<->connected)
Inactivity Timer Parameter
MO LNCEL
Nokia Parameter inactivityTimer
Huawei
MO Parameter RrcConnStateTimer UeInactiveTimer
Typical value of this inactivity timer is 10 seconds.
MO Rcs
Ericssons Parameter tInactivityTimer
DTX/DRX Discontinuous Transmission/ Reception • DRXDTX means UE transceiver is switc"e# o$$ $or some %re#e$ine# time %erio#s& T"is save %ower consum%tion on one si#e 'ut mi("t conse)uences in *on(er ca** setu% time an#or *ower user t"rou("%ut ac"ieva'*e& t"rou("%ut ac"ieva'*e&
+"at are DRXDTX o%tions, o%tions, %re#e$ine # time • In Idle mode for Paging - t"is o%tion means UE is *istenin( %a(in( messa(es in %re#e$ine# o%%ortunities on*y an# s*ee%in( a** ot"er time&&
• DRX/DTX in connected mode - UE is switc"e# o$$ $or %re#e$ine# time interva*&
DRX in Idle Mode
Discontinuous Reception for paging (TS 36.304) • The UE may use DRX in idle mode in order to reduce power consumption • One Paging Occasion (PO) is a subfra subframe me where where there there may may be P-RNTI transmitted on PDCCH addressing the paging message • One Paging Frame (PF) is one Radio Frame, Frame , which may contain one or multiple Paging Occasion(s) • When DRX is used the UE needs only to monitor one PO per DRX cycle defPagCyc cell specific paging DRX cycle duration . It also determines the maximum paging DRX duration applicable in the cell. Referred as “T” in 36.304 LNCEL; 32rf(0), 64rf(1), 128rf(2), 256rf(3); 128rf(2) 1rf = 1 radio frame = 10ms
pagingNb defines the number of possible Paging Occasions per radio frame , i.e. the density of paging occasions. This parameter is used to calculate the number of paging occasions within one paging DRX duration, which in turn is used to calculate the paging p aging occasion LNCEL; oneT(2), halfT(3), quarterT(4), oneEighthT(5), oneSixteenthT(6), oneThirtySecondT( o neThirtySecondT(7); 7); quarterT(4)
Example: quarterT = 1/4*T = 1 Paging Occasion PO in every 4th radio frame (40 (40 ms) ms) 32 PO’s PO’s / / DRX cycle duration (128 rf) rf)
Occasion of Paging Messages •
PCCH- The cell specific DRX cycle length Tsib is broadcasted by System Information ((PCCH- Config parameter defaultPagingCycle (in number of radio frames)
•
The UE specific DRX cycle length Tue might be received from core network from S1AP Paging Message as Optional IE. IE .
•
T=MIN(Tue,Tsib).. The used paging DRX Cycle T (in number of radio frames) is set to : T=MIN(Tue,Tsib) (Referred to as ' T ' in 3GPP TS 36.304)
•
The relationship relationship “paging “paging occasions - radio frame” frame” is given by the parameter parameter pagingNb provided in System Information (PCCH-Config ( PCCH-Config parameter parameter pagingNb). pagingNb). nB shall be interpreted interpreted as a calculation formula (how to derive paging occasions from T). For better understanding, the result of the calculation formula formula nB will be written as nB(T) in this section. Example: quarterT denotes nB(T)= 1/4*T (there is 1 paging occasion in every 4th radio frame).
Occasion of Paging Messages – Explain of Variables as per SFS (UE Behavior) •
Paging capacity is not a limiting factor as the Paging Channel (PCH) is mapped dynamically on the PDSCH.
•
N) gives the distance of radio frames with paging occasions. occasions. The calculation of the factor The factor (T (T div N) (T div N) is 2(i-k). The factor (UE_ID (UE_ID mod N) N) gives a relative index of a radio frame with paging occasions inside a Paging DRX cycle.. The calculation of factor (UE_ID mod N) is a simple mask operation for the last k bits. cycle N)*(UE_ID UE_ID mod N) gives the relative position of a radio frame with paging occasions relative The product (T div N)*( relative to the start start of a Paging_DR Paging_DRX X cycle. cycle. (SFN mod T) provides a SFN numbering relative to the start of a Paging-DRX cycle. cycle. The calculation of factor (SFN mod T) is a simple mask mask operation operation for the the last i bits.
• • •
Example (as per UE Behavior SFS, simplified, note the Tue Tue is smaller than allowed by 3GPP): Assumptions: Cell paging DRX Tsib = 32(frames), nB(T)=halfT, UE paging DRX Tue = 8 (frames)
Calculation: T = MIN(Tue,Tsib) = MIN(8,32) = 8 frames -> DRX cycle length nB(T) = half(8) = 4 -> paging occasions per DRX cycle N = MIN(T,nB(T)) = MIN(8,4) = 4 paging groups Ns = MAX(1, nB(T)/T) = MAX(1, 4 / 8) = MAX(1,0)= 1 subframe used for paging UE_ID = 3, assumption for this example (it could be any number) T div N = 8 div 4 = 2 -> distance between 2 radio frames with paging occasions UE_ID mod N = 3 mod 4 = 3 -> relative index of a frame with PO inside DRX (T div N)*(UE_ID mod 4) = 2*3 = 6 -> relative position of the PO inside DRX Let next reachable be SFN = 501; therefore (SFN mod T) = 5; therefore SFN for paging is 501+(6-5)=502. Simplified case (*to be shown in the picture) as the Tue is smaller than allowed by 3GPP.
Paging Related Parameter
MO
Nokia Parameter
LNCEL
defPagCyc
LNCEL
%a(in(N'
Huawei MO
PC PCCHC$( PCCHC$(
Parameter De$au*tPa(in(Cyc*e N'
Typical value of this default Paging Cycle is rf128 (1280 ms).
MO Pa(in( Pa(in(
Ericssons Parameter #e$au*tPa(in(Cyc*e n.
Paging Parameter on SIB 2 (Sample on QXDM Log file)
De$au*t Pa(in( Pa(in( Cyc*e an# Pan(in n. on SI./
DRX in Connecte Connected d Mode
DRX in RRC Connected Mode (RL30) Overview • • • •
Target: maximize UE battery lifetime by discontinuous monitoring of DL control channel (PDCCH) UE will be kept time aligned* DRX cycle is limited to 80ms Support of 3GPP defined long DRX cycle (short DRX cycle not supported) 3 different profiles supported: actDrx
1. DRX off optimized & 2. Voice optimized 3. Non-GBR
• • • •
activates the DRX in the cell. LNCEL; true(1),false(0); false(0)
The DRX profiles can be mapp mapped ed flexi flexibly bly to diffe different rent QCI profiles DRX profile of bearer with highest priority is applied in case of multiple bearers per UE DRX settings are signaled to UE via RRC messages DRX settings are applied only to UEs indicating related DRX capabilities
− Device type indication (non power limited devices do not benefit from DRX) provided by UE according to 3GPP Rel. 9 can be configured *Time alignment of the UL transmission is
drxApplyDeviceType Determines whether the device type “noBenFromBatConsumpOpt” “noBenFromBatConsumpOpt” shall be
DRX in RRC Connected Mode (RL30) DRX Status • DRX status could be:
drxLongCycle DRX cycle (note that only long DRX cycle supported) LNCEL; 20ms, 40ms, 80ms; depends on DRX profile
disabled:: – DRX disabled – UE always monitors PDCCH for UL and DL grants enabled:: – DRX enabled – Timeline is divided in DRX cycles of equal number of sub-frames – Start of DRX cycle is linked to SFN + offset (see backup slides) Active’ and periods the UE is – Within a DRX cycle there are periods the UE is ‘DRX ‘ DRX Active’ Sleep’ ‘DRX Sleep’ – DRX Sleep
– CQI / SRS / PMI P MI / RI shall not be reported – DRX Active – UE monitors PDCCH for UL and DL grants – UE is DRX active according to 3GPP TS36.321:
SFN = System Frame Number SRS = Sounding Reference Signal PMI = Precoding Matrix Indicator RI = Rank Indicator
– The On Duration Timer or the DRX Inactivity Timer or a DRX Retransmission Timer or the Contention Resolution Timer is running (see (see next slides )
– A Scheduling Request sent on PUCCH is pending – An UL grant for a pending HARQ retransmission can occur – A PDCCH (allocation) indicating a new transmission addressed to the C-RNTI C-RNTI of the UE has ha s not been received after successful reception of a Random Access Response for the signaled preamble
DRX in RRC Connected Mode (RL30) DRX Timers (1/3) • • • • • •
On duration timer: timer: Specifies the number of consecutive TTIs during which the UE shall monitor the PDCCH for possible allocations One per UE according to DRX profile Will always be started with the first subframe of a DRX cycle If running UE is DRX active Shall be set to a value that allows eNB to schedule a UE within the On Duration period with high probability if there are data to be transmitted
drxOnDuratT DRX on duration timer LNCEL;1, 2, 3, 4, 5, 6, 8,10ms ; depends on DRX profile
DRX in RRC Connected Mode (RL30) DRX Timers (2/3) •
DRX Inactivity timer:
•
Specifies the number of consecutive TTIs during which the UE shall monitor PDCCH after successfully decoding decoding a PDCCH indicating an initial UL or DL user data transmission transmission for this UE • Will be started or restarted if the PDCCH indicated a new UL or DL transmission and if the UE is DRX Active at that time • If running UE is DRX active • For bursty traffic the scheduler can keep the UE awake by scheduling it in a specific time window (with continuously grants to UE, DRX Inactivity Timer Window will be moved beyond the end of the DRX cycle) Re -Started at (2) DRX Inactivity Timer Started at (1) DRX Inactivity Timer
Note: If no further grants to UE during DRX Active time frame then the DRX Inactivity Timer will exceed and UE stops being DRX Active (not listening to PDCCH any more)
DRX On Duration
(1) DL grant on PDCCH + DL data on PDSCH
(2) DL grant on PDCCH + DL data on PDSCH
drxInactivityT DRX inactivity timer LNCEL;1, 2, 3, 4, 5, 6, 8,10, 20, 30, 40, 50, 60, 80ms ; depends on DRX profile
DRX in RRC Connected Mode (RL30) DRX Timers (3/3) •
DRX Retransmission Timer:
•
Specifies the maximum number of consecutive PDCCH sub-frames for possible allocations allocations as soon as a DL retransmission is expected by the UE Started after HARQ Timer* expires and DL data were not decoded successfully Purpose: Span a window within the UE listens on PDCCH for a retransmission in DL If running, UE is DRX active Stopped when PDCCH indicates a DL transmission and UE is DRX active at that time As UE is DRX Active when DRX Retransmission timer is running, eNB could schedule UE in DL or UL for new transmissions
• • • • •
Will be stopped at (3)
DRX Retrans. Timer
(1) DL grant on PDCCH + DL data on PDSCH
(2) NACK
(3) Retransmission of (1)
drxRetransT DRX retransmission timer LNCEL;2, 4, 6, 8ms ; depends on DRX profile
*HARQ timer is one per HARQ process. Define the
DRX in RRC Connected Mode (RL30) Example of UL Transmission Transmission in UL is possible while UE is DRX Sleep
DRX Inactivity Timer DRX On Duration
(1) UL grant on PDCCH
(2) UL transmission on PUSCH
(3) NACK on PHICH + UL grant for adaptive retransmission on PDCCH
(4) UL retransmission on PUSCH
In case that the transmission in (4) also failed, this subframe would be the next slot for giving an UL grant for a retransmission. Hence, this sub-frame belongs to the DRX Active time too.
•
UE has to monitor PDCCH in this sub-frame as an UL grant for a retransmission can occur, even if DRX OnDuration and DRX Inactivity timer expired
•
DRX Inactivity timer will not be started in this sub-frame as
DRX in RRC Connected Mode (RL30) DRX Profile Modeling • • •
The DRX profiles can be map mapped ped flex flexibly ibly to differ different ent QCI profiles qciTab is enhanced by an index to DRX profiles For each DRX profile index a DRX profile is provided DRX Profiles
QCI Table QCI 1
drxProfileIndex {1,2}, default 2
2 3 4 5 6 7 8 9
{1,2,3}, default 2 {1,2,3}, default 2 {1,2,3}, default 2 {1,2,3,4,5}, default 3 {1,3,4,5}, default 3 {1,3,4,5}, default 3 {1,3,4,5}, default 3 {1,3,4,5}, default 3
drxProfileIndex Id. of the corresponding DRX profile LNBTS: 1, 2, 3; depends on QCI (see table)
drxProfileIndex 1 2 3
drxProfilePriority 45 40 30
Further DRX parameters None (DRX is off)
drxProfileIndex DRX profile index. Uniquely identify a DRX profile LNCEL: 1,2,3; depends on drxProfileIndex (see table) drxProfilePriority DRX profile priority. Applied to identify the DRX profile to be used if UE has multiple bearers established LNCEL: LNCEL: 0..50; 1; depends on QCI (see table)
Extended DRX Settings (RL30) Overview • •
Extended setting for DRX in connected mode 2 additional DRX profiles with longer setting for the t he DRX cycle: – drxProfile4 applyOutOfSyncState Non-GBR: intermediate DRX Useful for e.g. QCI 5 IMS related traffic – drxProfile5 Non-GBR: Long DRX Useful for UE with bursty traffic, e.g. web browsing
Define which UEs should be sent in out of sync state LNCEL: LNCEL: extendedDrxOnly(0), extendedDrxOnly(0), allDrx(1), allUEs(2); extendedDrxOnly(0) (i.e. Only UEs configured with extended settings for the long DRX cycle )
• UL out-of-sync handling: • By using a very long setting for DRX cycle the UE is going out-of-sync (the time alignment is stopped some time after the UE has finished the data transmission) • In out-of-sync UE releases dedicated resources on PUCCH • The transition back to UL in-sync is done via Random Access procedure
• The choice to which UEs to apply the extended DRX setting could be set with applyOutOfSyncState parameter UEs with established GBR bearers are always kept UL in-Sync
Extended DRX Settings (RL30) • It should be avoided that UEs are being sent to RRC_IDLE immediately after UL out-of-sync detection • Let users go UL out-of-sync whenever there is no traffic activity for both UL and DL direction of all DRBs and SRBs • The (short) time frame until detection of no traffic activity is controlled by a eNB time: Short Term Inactivity Timer • If short term inactivity has been determined UE is going out-of-sync
• Short Term Inactivity Timer = max(minimumHOdelay max(minimumHOdelay , stInactFactor*drxInactivityT ) minimumHOdelay determines the minimum time for which a UE needs to be kept in DRX active following the most recent transmission of new data LNCEL;100..5000ms; 100ms; 500ms Vendor specific parameter
stInactFactor Short term inactivity factor. LNCEL: 0..10; 1; 1
drxInactivityT DRX inactivity timer LNCEL;1, 2, 3, 4, 5, 6, 8,10, 20, 30, 40, 50, 60, 80, 200, 300, 500, 750, 1280, 1920, 2560ms ; depends on DRX profile
DRX in Connected Mode: Parameters overview DRX Prof Profililes es – Su Summa mmary ry drxInactivityT [ms]
drxProfile1
drxLongCycle [ms]
drxOnDuratT [ms]
DRX disabled
drxProfilePriority
drxRetransT [ms]
0..50, step 1; 45
DRX disabled
drxProfile2
1,2,3,4,5,6,8
20,40
1,2,3,4,5,6 1,2,3,4,5,6,8,1 0
0..50, step 1; 40
2,4 2,4,6,8
drxProfile3
10,20,30,40,50,60, 10,20,30,40,50,60, 80
40,80 40,80
1,2,3,4,5,6 1,2,3,4,5,6,8,1 0
0..50, step 1; 30
2,4 2,4,6,8
drxProfile4
200,300,500 500,750, ,750, 1280,19 128 0,1920, 20, 2560
160,320 160, 320
10,20 10,20,30,40,50 ,30,40,50 ,60,80,100
0..50, step 1; 20
4,6,8,16 4,6,8,16,24,33 ,24,33
drxProfile5
750,1280,1920, 2560
640,1280,2560 640,1280,2560
10,20 10,20,30,40,50 ,30,40,50 ,60,80,100,200
0..50, step 1; 10
4,6,8,16 4,6,8,16,24,33 ,24,33
drxProfile1 DRX OFF
drxProfile2 Optimized for voice calls
drxProfile3 non-GBR bearers that allow for short settings of the long DRX cycle
drxProfile4 non-GBR bearers that allow for medium settings of the long DRX cycle cycle (e.g. (e.g. IM IMS S signaling)
drxProfile5 non-GBR bearers w/o specific latency requirements (e.g. web browsing)
DRX Related Parameter
MO
Nokia Parameter
Huawei
LNCEL actDrx
MO Dr0Para1rou%
Parameter EnterDr0Switc"
LNCEL LNCEL LNCEL LNCEL LNCEL LNCEL LNCEL LNCEL LNCEL LNCEL
Dr0Para1rou% Dr0Para1rou% Dr0Para1rou% Dr0Para1rou% Dr0Para1rou% Dr0Para1rou% Dr0Para1rou% Dr0Para1rou%
Lon(Dr0Cyc*e OnDurationTimer Dr0InactivityTimer Dr0ReT0Timer Dr0Para1rou%I# Su%%ortS"ortDr0 S"ortDr0Cyc*e Dr0S"ortCyc*eTimer
#r03%% #r03%%*yD *yDev evice iceT Ty%e y%e #r0Lon(Cyc*e #r0OnDuratT #r0InactivityT #r0RetransT #r0Pro$i*eIn#e0 actSmartDr0 #r0S"ortCyc*e #r0S"ortCyc*eT
Ericssons MO Parameter EUtranCe**2DD #r03ctive Dr0Pro$i*e Dr0Pro$i*e Dr0Pro$i*e Dr0Pro$i*e Dr0Pro$i*e
*on(Dr0Cyc*e onDurationTimer #r0InactivityTimer #r0RetransmissionTimer Dr0Pro$i*eI#
Dr0Pro$i*e Dr0Pro$i*e
s"ortDr0Cyc*e s"ortDr0Cyc*eTimer
DRX setting on RRCC RRCConne onnectionRe ctionReconfigu configuration ration messag message e (Sample on QXDM log file)
DRX Lon( Cyc*e DRX S"ort Cyc*e
Background and Additional Slides Background Slides
Occasion of Paging Messages 2or eac" case w"en w"en s%eci$ic UE s"a** 'e %a(e# in4 t"e ne0t a%%ro%riate ra#io $rame an# su'5$rame $or sen#in( t"e corres%on#in( RRC P31IN1 messa(e can 'e #erive# $rom6
N = MIN (T , nB(T )) T"e UE I#entity In#e0 7a*ue IE 8 UE_ID9 is %rovi#e# in t"e S:3P6 P31IN1 messa(e& T"e Pa(in( 1rou% Count on ra#io $rame *eve* 8N9 t"at is ca*cu*ate# $rom T an# n.8T96 N s = MAX (1, nB(T ) / T ) && 3s t"e n. va*ues $ourT an# twoT are not su%%orte# N is a*ways n.8T9& T"e num'er o$ su'5$rames use# $or %a(in( %er ra#io $rame 8 Ns9 8on*y $or t"ose ra#io $rames use# $or %a(in(9& 3s t"e n. va*ues $ourT an# twoT are not su%%orte# in RL/;4 Ns <: is va*i# $or a** cases& 1enera**y6 &
N s
=
MAX (1, nB(T ) / T )
Occasio Occ asion n of Pag Paging ing Mess Message ages s – Con Cont. t. The SFN of the radio frame for paging shall be calculated based on the following formula give by [3GPP 36.304]:
SFN mod T == (T div N ) * (UE _ ID mod N ) The sub frame number is given by chapter 7.2 of [3GPP 36.304]. Since Ns==1 is valid for all cases in the current release, the sub frame number shall always be set to 9 for FDD.
Calculation of DRX cycle start • Start of DRX Cycle DRX cycle will start in every sub-frame which meets the following equation:
[(SFN • 10) + subframe _ number ]mod( DRX _ cycle _ length ) = drxStartOf fset – RI reporting disabled drxStartOffset will will be calculated by eNB in such a way that the UE specific sp ecific periodic CQI report – drxStartOffset will be received at eNB in the same sub-frame which is addressed by the above given equation.
– RI reporting enabled CQI) will always – drxStartOffset will be calculated by eNB in such a way that both reports (RI & CQI) be received close together in a DRX cycle. (close together means: first comes RI report in subframe x and x and CQI report in sub-frame x+1) x+1)
THAN !"U
