Bearer Managemen Managementt
QoS Archit Ar chitectur ecture e and and Profiles Profiles in LTE Pr LTE QoS Architecture
Bearer Model in GTP and IETF Variants E- UTRAN
UE
E PC
eNB
S-GW
Internet
P-GW
Peer Entity
GTP variant:
End-to-end Service I P
EPS Bearer Radio Be Bearer
S1 Bearer
S5/S8 S5/ S8Bearer Bea rer
Radio
S1
S5 / S 8
E- UTRAN
UE
SGi
E PC
eNB
S-GW
Internet
P-GW
Peer Entity
End-to-end Service EPS Bearer Radio Be Bearer
S1 Bearer
Radio
S1
I P T r a n s p o r t
S5 / S 8
EPS bearer termination in PGW
T r a n s p o r t
I P T r a n s p o r t
SGi
IETF variant: EPS bearer termination in SGW
External Bearer
GTP: GPRS Tunneling Protocol
Simpli Sim plifica ficatio tions ns in QoS Pro Profile file 3G
EPS
Traffic Class
QCI (QoS Class Identifier)
Delivery Order
ARP
Max SDU Size SDU Format Information
Max Bit Rate
SDU Error Ratio
Guaranteed Bit Rate
Residual Bit Error Ratio Delivery of Erroneous SDUs
Aggregate Max Bit Rate
Transfer Delay Traffic Handling Priority Source Statistics Descriptor Signalling Indication ARP Max Bitrate Guaranteed Bitrate
For GBR bearers
For non-GBR bearers
• Number of QoS parameters has been decreased
• AMBR as part of rate cappin feature !"TE#$% is supported from R"&' AMBR: Aggregate Max Bit Rate for non-GBR EPS bearer
QoS Qo S Pa Para rame mete ters rs in in EPS EPS • QCI QCI:: QoS Cla Class ss Ident Identifi ifier er – QCI is used to determine packet forwarding treatment (e.g. scheduling of packets) – QCI is used to mark packets with DSCP (Differential Service Code Point) – 3GPP has standardized 9 QCI values and mapping to resource type (GBR, non-GBR), priority, packet delay budget and packet error loss rate
• ARP: Allocation & Retention Priority – ARP is used to decide whether bearer establishment or modification request can be accepted in case of resource limitations – ARP can also be used to decide which bearer(s) to drop during resource limitations – It has been agreed in 3GPP that ARP has no impact on packet forwarding treatment
• APN Aggregate Max Bit Rate APN-AMBR and UE Aggregate Max Bit Rate UEAMBR for non-GBR EPS bearers – APN-AMBR shared by all non-GBR EPS bearers with the same APN – APN – DL enforcement enforcement is done in PDN GW and UL enforcement in UE – UE-AMBR shared by all non-GBR EPS bearers of the UE – UE – DL & UL enforcement enforcement is done in eNB
• Guaranteed Bit Rate GBR and Max Bit Rate MBR for GBR EPS bearers
APN: Access Point Name AMBR: Aggregate Max Bit Rate for non-GBR EPS bearer DSCP: Differentiated Service Code Point DiffServ (QoS) uses the 6-bit Differentiated Differentiated Services Services
Supported QCIs • •
All standard QCIs for non-GBR and all GBR radio bearer services are supported. Feature LTE10 enable QCI=1 conversational voice.
Resource QCI Typ Type 1 GBR 2 GBR 3 GBR 4 GBR 5 NO NON-GBR 6 NON-GBR 7 NON-GBR 8 NON-GBR 9 NON-GBR
Packet Delay Packet Priority Budget Loss Rate 2 100 ms 1.0E-02 4 150 ms 1. 1.0E-03 3 50 ms 1.0E-03 5 300 ms 1. 1.0E-06 1 100 ms 1.0E-06 6 300 ms 1.0E-06 7 100 ms 1.0E-03 8 300 ms 1.0E-06 9 300 ms 1.0E-06
Defau Def ault lt QCI Support ENABLED ENABLED ENABLED ENABLED ENABLED ENABLED ENABLED ENABLED ENABLED
RLC PDCP DRX Default Profile Profile profile RLC Mode Index Index Indx RLC_UM 101 101 2 RLC_UM 102 102 2 RLC_UM 103 103 2 RLC_UM RL 2 2 2 RLC_UM RL 2 2 3 RLC_AM 2 2 3 RLC_AM 2 2 3 RLC_AM 2 2 3 RLC_AM 2 2 3
• QCI values > 9 are mapped into QCI 9. • Parameters per QCI can be controlled on LNBTS level by qciTab. qciTab Structure {delayTarget, drxProfileIndex, dscp, l2OHFactorDL, l2OHFactorUL, Lcgid, maxGbrDl, maxGbrDl, maxGBRUl, pdcpProfIdx, prio, prio, qci, qciSupp, resType, rlcMode, rlcProfIdx, schedulBSD, sch edulBSD,
LNBTS: qcitabx dscp
tab x not all parameters apply to all QCI profiles LNBTS: qci tab The maximum packet delay value used by the eNB MAC scheduling algorithm. algorithm. Only for QCI=1. .delayTarget drxProfileIndex Specifies Specifies the ID of the correspond corresponding ing DRX profile. profile. dscp l2OHFactorDL l2OHFactorUL Lcgid MaxGbrDL MaxGbrUL pdcpProfIdx prio qci qciSupp resType rlcMode rlcProfIdx schedulBSD schedulPrio schedulType schedulWeight
This parameter configures the DSCP (Differentiated Services Code Point). Specifies the overhead factor of the downlink GBR in layer 2. Only for QCI=2,3,4. Specifies the overhead factor of the uplink GBR in layer 2. Only for QCI=2,3,4. Logical Channel Group Identifier for buffer status reporting. Specifies the maximum value of the GBR in the downlink direction. Only for GBR QCI. Specifies the maximum value of the GBR in the uplink direction. Only for GBR QCI. This parameter specifies the corresponding PDCP profile in the PDCP profile list. This parameter gives the priority of the EPS bearer. QoS Class Identifier. Identifier. The given QCI is supported and enabled in this release . Permanent network resources allocated for GBR. Configures the RLC mode of the radio bearer based on the corresponding QCI. This parameter specifies the corresponding RLC profile in the RLC profile list. Configure the Bucket Size Duration (BSD) of the UL scheduler. Logical Channel Priority for the UE scheduler. Specifies how the EPS bearer with this QCI is scheduled. Only for QCI=5. Specifies the scheduling weight for eNB schedulers. Only for Non GBR QCI.
configures DSCP value associated with the QCI; DSCP value will be set se t in each IP packet sent for the related bearer to S-GW or target eNB. L2SWI; L2SWI; 0 - 63; 1; -
Example: LNBTS: qcitabx LNBTS: qcitab x in eNB SCF file
• qcitab1 and qcitab2 shown
-
- -
80ms
46
1
101
2
1
ENABLE
GBR
RLC_UM
101
100ms
5
2
144
31
-
- -
2
26
2
102
4
2
DISABLE
GBR
RLC_UM
102
100ms
7
80ms
16
35
144
Operator Specific QCI (RL30) actOperatorQCI activates the support of the establishment of EPS bearers withc QCI in range 128…154 LNCEL; true(1),false(0); false(0)
•
In RL RL30 30 – up to 21 additional QCIs are defined • Only for non-GBR bearers • QCI range is 128…254 • LNBTS: qci qciTab TabOperator Operator is a structure parameter with 13 parameters • Mostly same parameters as the standard QCIs • Main differentiation of QCIs by scheduling weights (and DSCPs) • For each QCI an additional counterGroup is defined • Examples of Counter Groups for the typical use cases: • 1. Better user and service differentiation for non-GBR services for one operator: – Bronze users: QCI: 130, 131, 132, 133 Counter Group 1 – Silver users: QCI: 140, 141, 142, 143 Counter Group 2 – Gold users: QCI: 150, 151, 152, 153 Counter Group 3
• 2. RAN sharing (operators share eNodeB) to define a set of QCIs dedicated for each operator: – Operator A:
QCI: 140, 141, 142, 143
Counter Group 1
counterGroup The counter group to which the QCI belongs LNCEL; 1..6;1; -
Samp Sa mple le QoS QoS ass assig ignm nmen entt on At Attac tachA hAcc ccep eptMs tMsg g (Q (QXD XDM) M)
+oS +oS for +,+,-. . Transfer (e)a/ is #'' ms
(efau)t Bearer *ith +,- .
APN AMBR !Areate !Areate Ma0imum Bit Rate%
Samp Sa mple le QoS QoS ass assig ignm nmen entt on At Attac tachA hAcc ccep eptMs tMsg g (Q (QXD XDM) M)
4e et -P Address Address after after Att Attach ach Accept Accept Ms Samp)e : #5&6#216$56&1
4e et et TMS TMS--
QCI tab Parameter M9 "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS "NBTS
No7ia Parameter de)a/Taret dr0Profi)e-nde0 dscp )&98actor(" )&98actor4" )cid ma0Gbr() ma0Gbr4) pdcpProf-d0 prio ;ci ;ciSupp resT/pe r)cMode r)cProf-d0 schedu)BS(
"NBTS "NBTS "NBTS
schedu)Prio schedu)T/pe schedu)Weiht
8ua*ei M9 ,e))Standard+ci ,e))Standard+ci -pService+os
Parameter TrafficRe)(e)a/ (r0ParaGroup-d (scp
,e))4)schA)o
8ead9verheador4)Sch
Ericssons M9 +ciProfi)ePredefined +ciProfi)ePredefined +ciProfi)ePredefined
Parameter pdb dr0Profi)eRef dscp
)oica),hanne)GroupRef d)MinBitRate u)MinBitRate pdcp pdcpSN SN"e "en nth th priorit/ ;ci
Standard+ci E0tended+ci
()MinGbr 4)MinGbr
StandardQci
RlcPdcpParaGroupId
Standard+ci
+ci
+ciProfi)ePredefined +ciProfi)ePredefined +ciProfi)ePredefined +ciP +ciPrrofi) ofi)eP ePrrede edefine fined d +ciProfi)ePredefined +ciProfi)ePredefined
StandardQci
RlcPdcpParaGroupId
+ciProfi)ePredefined +ciProfi)ePredefined +ciP +ciPrrofi) ofi)eP ePrredefin fined
resourceT/pe r)cMode r)c r)cSN" SN"enth
StandardQci
DlschPriorityFactor. UlschPriorityFactor
+ciP +ciPrrofi) ofi)eP ePrrede edefine fined d +ciProfi)ePredefined
re)at e)ativ iveP ePri rior orit it/ / d)ResourceA))ocationStrate/
Default and Dedicat Default Dedicated ed Bearer Bearerss
Default Bearers • The initia) Default EPS Bearer is created as part of the "TE Attach procedure6
– 4E is a))ocated an -P address6 – +oS is based on the +,- and and associated associated parameters6 parameters6 • Additiona) (efau)t EPS Bearers ma/ be created *hen simu)taneous access to services avai)ab)e via mu)tip)e Access Point Names !APN% is needed6 – Trier of an additiona) (efau)t EPS Bearer is initiated b/ 4E6 non
eNB
EP C S-GW
SRB1 SRB2 Default EPS Bearer
Internet P-GW
Dedicated EPS Bearers •
•
Dedicated EPS Bearers !nonconversationa) voice? on GBR dedicated EPS bearers – R"$' supports operator operator specific +,- bearers bearers – R"3' supports +,-@ &@$@3 and mu)tip)e GBR bearers per 4E – R"' supports up to 2 EPS bearers – R"2' supports up to 1 EPS bearers
4E ma/ have mu)tip)e dedicated EPS bearers )in7ed to a defau)t EPS bearer6 E-UTRAN EP C UE
eNB
S-GW
Internet P-GW
SRB1 SRB2 Default EPS Bearer Dedicated EPS Bearer Dedicated EPS Bearer
TFT: Traffic Flow Template; single UE can have multiple SAE bearers ⇒ system requires kind of packet filter (UL & DL TFT) to decide
Multiple EPS Bearers
LTE520 8 EPS Bearers Multiple sessions with different QoS The Flexi Flexi Multiradio Multiradio BTS supports supports up to 8 EPS EPS bearers. bearers. The following following radio bearer bearer combinations combinations per UE are supporte supported d by Nokia Flexi Flexi Multiradio Multiradio BTS: – SRB1 + SRB2 + 6 x AM DRB – SRB1 + SRB2 + 7 x AM DRB – SRB1 + SRB2 + 8 x AM DRB – SRB1 + SRB2 + 4 x AM DRB (+ 3 x UM DRB) – SRB1 + SRB2 + 5 x AM DRB (+ 2 x UM DRB) actMultBearers activates the support of multiple – SRB1 + SRB2 + 5 x AM DRB (+ 3 x UM DRB) EPS Bearers. SRB (signaling radio bearer)
LNCEL; true,false; true
GBR EPS bearer Non-GBR EPS bearer GBR EPS bearer
SRB1: for RRC messages SRB2: for NAS messages UE
Flexi Multiradio BTS
S-GW
act8EpsBearers activates the support of up to 8 EPS bearers. LNCEL; true,false; false
Ue re requ quir irem emen entt for for 8 EPS EPS Bear Bearer er FGI (Feature Group Indicator) for supported bearer combination found on FGI Bit 7 and Bit 20 • Bit 7 indicated if RLC UM is supported. sup ported. – Bit 7 can only be set to 0 if the UE does not support VoLTE • Bit 20 is set to 1 then – If Bit 7 is set to 0 UE support
SRB 1 and SRB2 for DCCH + 8 AM DRB
– If Bit 7 is set to 1 UE support
SRB 1 and SRB2 for DCCH + 8 AM DRB SRB 1 and SRB2 for DCCH + 5 AM DRB + 3 UM DRB
• Regardless of what Bit 7 and Bit 20 is set to. UE shall support at least – SRB1 and SRB2 for DCCH + 4x AM DRB
• Regardless of what Bit 20 is set to, if bit 7 is set to 1. UE shall support at least – SRB1 and SRB2 for DCCH + 4x AM DRB + 1x UM DRB
FGI sampl sample e on UeCapab UeCapability ilityInform Information ation (Nemo Analy Analyzer) zer)
4e supp support ort R", R", 4M 4M
4e support support 1 EPS Bearer Bearer
Support of Multiple EPS Bearers • Multip Multiple le DRB (data radio bearers) bearers) can be either multiple multiple default default EPS bearers or or a combina combination tion of default and dedicated EPS bearers. total al number number of DRB DRB per cell cell and • The radio admission is extended by additional check of the tot maximum number of DRB per UE. UE . • The different EPS bearers per UE can have the same or a different QCI. TFT
LTE9 Service Differentiation for non-GBR EPS Bearers QCI based service differentiatio differentiation n •
The service differentiation functionality allows to assign relative scheduling weight we ights s for each each non-GBR non-GBR QCI QCI on cell cell level. level.
•
The relative weight will be considered by the UL & DL scheduler. scheduler .
•
The service differentiation functionality allows further on to define 3 different RLC/PDCP profiles per BTS which can be assigned to different QCIs.
•
The operator can enable/disable the support of individual QCIs.
•
Services are transferred to bearers which are mapped to QCIs actnonGbrServiceDiff activates the Service Differentiation for non-GBR Bearers. LNCEL; true,false; true
EPS Bearers for Conversational Voice
EPS Bearers for Conversational Voice • Voice service service shall be transmitted transmitted using dedicate dedicated d bearers. bearers. Voice requires requires two bearers: – QCI 1 for user data – QCI 5 for IMS signaling E-UTRAN UE
EP C
eNB
S-GW
Internet
actConvVoice Activates the support of the conversational voice bearer LNCEL; false, true; false
P-GW
SRB1 SRB2
VoIP GBR, UM, QCI=1
Default EPS Bearer (AM)
VoIP GBR, UM, QCI=1
Dedicated EPS Bearer (UM)
Radio
S1-U
S5 /S8
SGi
No7ia
8ua*ei
Emergenc Calls
Emergency Call Handling (1/2) • -ntroduces ,ircuit S*itch a))bac7 functiona)it/ app)icab)e to emerenc/ ca))s on)/ • Emerenc/ ca))s are redirected to GSM or W,(MA actEmerCallRedir activates the feature 'Emergency Call Via Redirection'. LNBTS; Disabled Disabled (0), (0), Enabled Enabled (1);- ; Disabled (0)
• There are t*o cases:
Case 1: 4E is id)e mode@ eNB chec7s RR, ,onnection Re;uest for ca)) estab)ishment cause and in case it is CEmerenc/C@ then a separate admission thresho)d is used and ca))s *i)) not be reDected due to capacit/ )icense )imitations RRCConnectionEstablishmentRequest, RRCConnectionEstablishment Request, Cause: Emergency
UE initials an emergency call
Admission control: Admitted CS Fallback Redirect to UTRAN or GSM
No7ia
8ua*ei
Ericssons
Emergency Call Handling (2/2) Case2: MME is sendin ,S a))bac7 -ndicator -E *ith va)ue C,S a))bac7 8ih Priorit/C MME initials an emergency call
MME CS Fallback High Priority
CS Fallback Redirect to UTRAN or GSM
IMS Emergency Sessions • • •
IMS is an access-independent architecture that enables various types of multimedia services to end users using common Internet based protocols LTE 572 provides support for IMS based emergency sessions for release 9 UEs Two bearers are required: • •
• •
One bearer for SIP signaling One bearer for VoIP
An IMS emergency session is established and kept with preference compared to normal sessions An emergency session is recognized by: • •
RRC connection request message with establishment es tablishment cause “emergency” EPS bearer with ARP value matching the per PLMN configurable ARP value reserved for emergency calls The PLMN id. Supporting emergency emerSessArpPrioLev sessions is defined by following actIMSEmerSessR9 Activate the IMS Emergency sessions LNBTS; false(0), true (1); false(0)
IMS: IP Multimedia Subsystem
ARP priority level used by PLMN Id. For emergency sessions. The range of ARP is 1..15 but for emergency only ARP 1..8 allowed.
parameters:
LNBTS; 1..8;1; 1 (Highest priority for emergency calls)
LNBTS: emerSess emerSessMncLen MncLen
LNBTS: emerSess emerSessMcc Mcc LNBTS: emerSess emerSessMnc Mnc LNBTS: emerSessArpPrioLev
!ate Capping !ate Capping
Rate Capping • Feature objective: • Limitation of the UL & DL bit rate of all non-GBR bearers per UE below UEAMBR • The subscription parameter is stored in HSS and signaled to eNodeB during bearer setup
• Benefits: • Allow introducing xDSL-like pricing models rcEnableDl/ Ul
• Flat rate • Differentiation by subscribed max. data rate
Enable DL (or UL) rate capping LNCEL; false(0), true (1); false(0)
• Improves utilization of the radio interface
• Note: GBR bearers are outside of scope of the UE-AMBR No7ia M9
Parameter
Ericssons M9
Parameter
Rate Capping • RRM Scheduler function: • Introduces throughput measurements filters in the scheduler that controls the UE throughput according to UE-AMBR values • Measured AMBR of all non-GBR bearers is averaged over 1 second and compared to UE-AMBR • Scheduler restricts the physical resources (the number of PRBs) of the UE • AMBR is not exceeded • Calculates the limited amount of PRBs depending on the UE-AMBR • Remove the restriction of PRB assignment in case AMBR falls below UE AMBR rcAmbr rcA mbrMgn MgnDl Dl / Ul Factor to calculate margin for AMBR to account for overhead of PDCP and RLC (DL & UL) LNCEL; 1…1.5;0.01; 1.03/1.02
e! e!A AB Modification Mod odif ific ica ati tio on e!AB
eRAB eRA B Mod Modifi ificati cation on LTE5 TE519 19 •
An EPS bearer is the level of granularity granularity for bearer bearer level QoS QoS control in the the E-UTRAN/EPC)
Motivation: e-NB analysis provided QoS for each EPS Bearer to get the type of modification According the feature LTE519 e-NB decides about RAB modifications and handling
•
EPS Bearer Bearer is identified by a set set of QoS parameters parameters • QCI -> (QoS Class Identifier) • ARP -> (Allocation and Retention Priority) • GBR -> (Guaranteed Bit Rate)
- Feature Feature utilization utilization LTE9 use service differentiation LTE519 modifies the scheduling weight introduced by LTE9 LTE13 Rate Capping LTE519 modifies the UE-AMBR introduced by LTE13
eRAB eRA B Mod Modifi ificati cation on LTE5 TE519 19 •
Without the feature LTE519, LTE519, eNB will reject any modification attempt commanded by MME via S1AP: E-RAB E-RAB MODIFY MODIFY REQUEST REQUEST message. message. • In this case S1AP: E-RAB MODIFY RESPONSE RESPONSE message includes IE: cause set to “Radio Network Netw ork Layer Layer Cause Cause – Unspecifi Unspecified” ed”
•
With the feature LTE519 modification of the following parameters can handled by eNB • Non-GBR Bearers • QCI, QCI, ARP, ARP, UE-AM UE-AMBR BR • GBR Bearers • ARP
•
Modification of QCI,GBR QCI,GBR and MBR for for GBR EPS Bearers is planned for a future release. release.
eRAB eRA B Mod Modifi ificati cation on LTE5 TE519 19
EPS Bearer Modification procedure for QCI/ARP change triggered by the S1AP message E-RAB MODIFY REQUEST.
!"#C
Motivation for ROHC (LTE11) • IP/ IP/UD UDP/R P/RTP TP he head aders ers size can be either 40 byte tes s (52% of a packet) for IPv4 or even 60 bytes (63%) for IPv6 This means enormous waste of energy for transmitting headers instead of speech data
In order to prevent that waste, in RL20, in parallel to LTE10 Conversational Voice, Voice, there is also LTE11 feature which provides the functionality of Robust Header Compression •
ROHC, a 10 minutes of 12.2 kbps AMR coded VoIP call with talk spurt/silent • For example, with ROHC, period alternating every 1 second (SID packets packets excluded), excluded), the transmission overhead is reduced by 91.5%
actPdcpRohc activates the usage of PDCP Robust Header Compression
M9
No7ia Parameter
M9
8ua*ei Parameter
Ericssons M9
Parameter
Idea of Compression Uncompressed transmission
IP/UDP/RTP header consisting of predictable and unpredictable fields subjected to compression
Compressed transmission
MAC header, RLC header, VoIP payload, CRC checksum chec ksum - not subjected subjected to compression
„from now on assume Destination IP is 10.0.0.10”
x
10.0.0.10
10.0.0.10
6
10.0.0.10
3
3
10.0.0.10
7
7
10.0.0.10
0
0
10.0.0.10
1
1
10.0.0.10
8
8
6
rohcMaxCid Field predictable in the course of transmission transmiss ion „Destination IP”
Unpredictable field
configures the max. number of ROHC contexts used for a DRB in one direction. The max. number of ROHC contexts is also restricted by UE capabilities
Initial transmission, „context” is initialized so that next transmissions transmiss ions can be compressed
In the course of transmission header fields initialized in context do not have to be transmitted
Context - information about all fields that are predictable and their change patterns sent in the beginning of transmission to allow header compression
T#A$% &"'
