05_rac_gc
TRANSCRIPT
1 © Nokia Siemens Networks RA41215EN20GLA1
Radio Admission Control (RAC)LTE Radio Parameters RL20
3 © Nokia Siemens Networks RA41215EN20GLA1
1. LTE Functionalities and Overview
2. Channel Configuration
3. General parameter DB structure and System Information Broadcast
4. Random Access
5. Radio Admission Control (RAC)
6. Radio Bearer Control & DRX /DTX Management
7. LTE Mobility Management
8. UL/DL Scheduler
9. MIMO Mode Control (MIMO-MC)
10.Power Control
Contents
4 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
5 © Nokia Siemens Networks RA41215EN20GLA1
Radio Admission Control Introduction 1
• Scope of RAC is cell level• RAC algorithms controls establishment of
– Signaling radio bearer– Data Radio Bearer
• RAC controls number of UE in a cell– Number of established RRC connection per cell– Number of active UEs (users) per cell
• RAC controls number of DRB in a cell– Number of data radio bearers (DRB)– Number of DRB with QCI=1
• RAC controls emergency calls and emergency sessions– Special margin considered for emergency calls– Special margin considered for IMS emergency sessions (RL30)
6 © Nokia Siemens Networks RA41215EN20GLA1
Radio Admission Control Introduction 2
• RAC applies different criteria for call estblishment and Mobility (HO)
– offset in terms of number of rrc connections or active users used, etc
– aim is to keep the already established sessions active and support user mobility
• RAC interacts with other RRM entities– Packet Scheduler
– Mobility management
– Radio Bearer Management
– UE State Management
• RAC acts based on events like:– paging
– Handover Request
– Call establishment request
7 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
8 © Nokia Siemens Networks RA41215EN20GLA1
Bearer model in GTP and IETF variants
P-GWS-GW PeerEntity
UE eNB
EPS Bearer
Radio Bearer S1 Bearer
End-to-end Service
Radio S5/ S8
Internet
S1
E-UTRAN EPC
SGi
S5/S8 Bearer
P-GWS-GW PeerEntity
UE eNB
EPS Bearer
Radio Bearer S1 Bearer
End-to-end Service
Radio S5/ S8
Internet
S1
E-UTRAN EPC
SGi External Bearer
IP
Transport
IP
Transport
IP
Transport
GTP variant:
EPS bearer termination in PGW
IETF variant:
EPS bearer termination in SGW
IETF: Internet Engineering Task Force
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Simplifications in QoS profile
3G EPSQCI (QoS Class
Identifier)
ARP
Max Bit Rate
Guaranteed Bit Rate
Aggregate Max Bit Rate
For GBR bearers
For non-GBR bearers
• Number of QoS parameters has been decreased• AMRB as part of rate caping feature (LTE13) is supported in RL20
Guaranteed Bitrate
Delivery Order
Max SDU Size
SDU Format Information
SDU Error Ratio
Residual Bit Error Ratio
Delivery of Erroneous SDUs
Transfer Delay
Traffic Handling Priority
ARP
Source Statistics DescriptorSignalling Indication
Max Bitrate
Traffic Class
10 © Nokia Siemens Networks RA41215EN20GLA1
QoS parameters in EPS
• QoS Class Identifier (QCI)– 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
• Allocation and Retention Priority (ARP)– 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 (UE-AMBR) for non-GBR EPS bearers
– APN-AMBR shared by all non-GBR EPS bearers with the same APN – downlink enforcement is done in PDN GW and uplink enforcement in UE
– UE-AMBR shared by all non-GBR EPS bearers of the UE – downlink and uplink enforcement is done in eNB
• Guaranteed Bit Rate (GBR) and Max Bit Rate (MBR) for GBR EPS bearers
11 © Nokia Siemens Networks RA41215EN20GLA1
Standardized QCIs
GBR1
Resource type
Packet delay budget
Packet error loss rate Example ApplicationQCI
GBR
100 ms 1e-2 Conversation voice
2
GBR
150 ms 1e-3 Conversational video
3
GBR
50 ms 1e-3 Real-time gaming
4
Non-GBR 100 ms 1e-6 IMS signalling5
Non-GBR 300 ms 1e-6 Video, www, email, ftp6
Non-GBR7
Non-GBR8
Non-GBR9
Priority
2
4
3
1
6
7
8
9
300 ms 1e-6 Non-conversational video5
100 ms
300 ms
300 ms
1e-3
1e-6
1e-6
Interactive gaming
Video, www, email, ftp
Video, www, email, ftp
Note: Usage of operator specific QCIs in addition to standardized QCIs is possible (future).
12 © Nokia Siemens Networks RA41215EN20GLA1
RL20 supported QCIs
• NSN RL20 release supports the QCIs for non-GBR radio bearer services: QCI 5, 6, 7, 8 and 9
• In addtion features such as LTE10 enable QCI=1 conversational voice.
• QCI values > 9 are mapped into QCI 9.
• Parameters per QCI can be controlled on LNBTS level by qciTab.
QCIResource
Type Priority
Packet Delay
Budget
Packet Loss Rate
Default QCI Support
Default RLC Mode
RLC Profile Index
PDCP Profile Index
Further QoS
param.1 GBR 2 100 ms 1.0E-02 - - - - ...2 GBR 4 150 ms 1.0E-03 - - - - ...3 GBR 3 50 ms 1.0E-03 - - - - ...4 GBR 5 300 ms 1.0E-06 - - - - ...5 NON-GBR 1 100 ms 1.0E-06 - - - - ...6 NON-GBR 6 300 ms 1.0E-06 ENABLED RLC_AM 1 1 ...7 NON-GBR 7 100 ms 1.0E-03 ENABLED RLC_AM 1 1 ...8 NON-GBR 8 300 ms 1.0E-06 ENABLED RLC_AM 1 1 ...9 NON-GBR 9 300 ms 1.0E-06 ENABLED RLC_AM 1 1 ...
qciTabStructure {qci, resType, prio, Lcgid, qciSupp, rlcMode, rlcProfIdx, pdcpProfIdx, dscp, schedulWeight, schedulPrio, delayTarget}LNBTS;- ;9 ; -
13 © Nokia Siemens Networks RA41215EN20GLA1
LNBTS: qcitabx
LNBTS: qcitabx is a structured parameter with 12 parameters
dscp This parameter configures the DSCP (Differentiated Services Code Point)
Lcgid Logical Channel Group Identifier for buffer status reporting
pdcpProfIdx This parameter specifies the corresponding PDCP profile in the PDCP profile list.
prio This parameter gives the priority of the EPS bearer.
qci QoS Class Identifier.
qciSupp The given QCI is supported and enabled in this release
resType Permanent network resources allocated for GBR
rlcMode Configures the RLC mode of the radio bearer based on the corresponding QCI
rlcProfIdx This parameter specifies the corresponding RLC profile in the RLC profile list
schedulBSD Configure the Bucket Size Duration (BSD) of the UL scheduler
schedulPrio Logical Channel Priority for the UE scheduler
schedulType Specifies how the EPS bearer with this QCI is scheduled. Only for QCI=5
schedulWeight Specifies the scheduling weight for eNB schedulers
delayTarget The maximum packet delay value used by the eNB MAC scheduling algorithm. Only for QCI=1
14 © Nokia Siemens Networks RA41215EN20GLA1
LNBTS: qcitabx in
eNB SCF file
• qcitab1 and qcitab5 shown
Example: LNBTS: qcitabx
15 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
16 © Nokia Siemens Networks RA41215EN20GLA1
Default Bearers
• The initial Default EPS Bearer is created as part of the LTE Attach procedure.– UE is allocated an IP address.– QoS is based on the QCI and associated parameters.
• Additional Default EPS Bearers may be created when simultaneous access to services available via multiple Access Point Names (APN) is needed.– Trigger of an additional Default EPS Bearer is initiated by UE.– Default EPS Bearers are always non-GBR.
P-GWS-GWUE eNB
InternetE-UTRAN EPC
Radio S1-U S5 /S8 SGi
Default EPS Bearer
SRB2
SRB1
17 © Nokia Siemens Networks RA41215EN20GLA1
Dedicated EPS Bearers • Dedicated EPS Bearers (non-GBR or GBR) are created for QoS differentiation purposes.
– The IP address allocated for the default bearer is used for the dedicated EPS bearers within the same PDN connection.
– Utilization of default or dedicated EPS bearers is based on a Traffic Flow Template (TFT).
– Dedicated EPS Bearers are created by network.– RL20 supports multiple dedicated EPS bearers (not supported in RL10)– RL20 supports “conversational voice” on GBR dedicated EPS bearers (not supported
in RL10)
• The UE may have multiple dedicated EPS bearers linked to a default EPS bearer.
P-GWS-GWUE eNB
Default EPS Bearer
InternetE-UTRAN EPC
Radio S1-U S5 /S8 SGi
Dedicated EPS Bearer
Dedicated EPS Bearer
SRB2
SRB1
18 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
19 © Nokia Siemens Networks RA41215EN20GLA1
LTE7 Support of multiple EPS bearers
The Flexi Multiradio BTS supports up to four EPS bearers.
The following radio bearer combinations per UE are supported by the Flexi Multiradio BTS:– SRB1 + SRB2 + 1 x AM DRB (+ 1 x UM DRB with LTE10)
– SRB1 + SRB2 + 2 x AM DRB (+ 1 x UM DRB with LTE10)
– SRB1 + SRB2 + 3 x AM DRB (+ 1 x UM DRB with LTE10)
– SRB1 + SRB2 + 4 x AM DRB (+ 1 x UM DRB with LTE10)
Multiple sessions with different QoSMultiple sessions with different QoS
GBR EPS bearer
Non-GBR EPS bearer
SRB (signaling radio bearer)
Flexi Multiradio BTS S-GWUE
Note: LTE10 EPS bearers for conversational voice
actMultBearersactivates the support of multiple EPS Bearers.
LNCEL; true,false; true
20 © Nokia Siemens Networks RA41215EN20GLA1
LTE7 Support of multiple EPS bearers
• Multiple DRB (data radio bearers) can be either multiple default EPS bearers or a combination of default and dedicated EPS bearers.
• The radio admission is extended by additional check of the total number of DRB per cell and maximum number of DRB per UE.
• The different EPS bearers per UE can have the same or a different QCI.
21 © Nokia Siemens Networks RA41215EN20GLA1
• The service differentiation functionality allows to assign relative scheduling weights for each non-GBR QCI on cell level.
• The relative weight will be considered by the uplink and the downlink scheduler.
• The service differentiation functionality allows further on to define three different RLC/PDCP profiles per BTS which can be assigned to different QCIs.
• The operator can enable/disable the support of individual QCIs.
LTE9 Service differentiation for non-GBR EPS bearers
QCI based service differentiation QCI based service differentiation
actnonGbrServiceDiffactivates the Service Differentiation for non-GBR Bearers.
LNCEL; true,false; ; true
22 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
23 © Nokia Siemens Networks RA41215EN20GLA1
LTE10 EPS Bearers for Conversational Voice
• In RL20 voice service shall be transmitted using dedicated bearers. Voice requires two bearers:– QCI 1 for user data
– QCI 5 for IMS signaling
P-GWS-GWUE eNB
Default EPS Bearer (AM)
InternetE-UTRAN EPC
Radio S1-U S5 /S8 SGi
SRB2
SRB1
Dedicated EPS Bearer (UM)VoIP GBR, UM, QCI=1
VoIP GBR, UM, QCI=1
actConvVoiceActivates the support of the conversational voice bearerLNCEL; false, true; false
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QCI translation table for QCI1,5-9
Parameter NameDefaults QCI1
Defaults QCI5
Defaults QCI6
Defaults QCI7
Defaults QCI8
Defaults QCI9
QCI 1 5 6 7 8 9
Resource Type 0(GBR) 1(NonGBR) 1(NonGBR) 1(NonGBR) 1(NonGBR) 1(NonGBR)
Priority 2 1 6 7 8 9
QCI Support 1 1 1 1 1 1
RLC Mode RLC_UM RLC_AM RLC_AM RLC_AM RLC_AM RLC_AM
RLC Profile Index 101 1 2 1 2 2
PDCP Profile Index 101 1 2 1 2 2
Logical Channel Group Id 1 2 3 2 3 3
Scheduling BSD 1 1 3 1 3 3
Scheduling Priority 5 9 9 10 11 12
Scheduling Type* n/a 1 n/a n/a n/a n/a
Scheduling Weight n/a 40 20 10 5 1
DelayTarget 80ms n/a n/a n/a n/a n/a
DSCP 46 34 18 20 10 0
DSCP to PHB map AF41 AF41 AF21 AF22 AF11 BE
PHB queue weight list 10000 10000 100 100 10 1
* - only for QCI5
For UL and DLFor UL and DL
Not modifiable
LTE131 Traffic prioritization on IP
layer (DiffServ)
Not modifiable
Not modifiable
RRM configuration related parameters
Not modifiable
Has to be set to 0 (signaling) when using
LTE10
If actnonGbrServiceDiff “disabled” QCI9 must be
“enabled”
QOS/dscpMap
QOS/perHopBehaviourW
eightList
25 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
26 © Nokia Siemens Networks RA41215EN20GLA1
Motivation for ROHC (LTE11)
• IP/UDP/RTP headers size can be either 40 bytes (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, there is also LTE11 feature which provides the functionality of Robust Header Compression
• For example, with ROHC, a 10 minutes of 12.2 kbps AMR coded VoIP call with talk spurt/silent period alternating every 1 second (SID packets excluded), the transmission overhead is reduced by 91.5%
actPdcpRohcactivates the usage of PDCP Robust Header CompressionLNCEL; false, true; false
27 © Nokia Siemens Networks RA41215EN20GLA1
Idea of compression
IP/UDP/RTP header consisting of predictable and unpredictable fields - subjected to compression
Field predictable in the course of transmission -
„Destination IP”
MAC header, RLC header, VoIP payload, CRC
checksum - not subjected to compression
10.0.0.10
10.0.0.10
10.0.0.10
10.0.0.10
10.0.0.10
10.0.0.10
6
3
7
0
1
8
„from now on assume Destination IP is 10.0.0.10”
10.0.0.10 6
3
7
0
1
8
x
Uncompressed transmission
Compressed transmission
Unpredictable field
Initial transmission, „context” is initialized so that next
transmissions can be compressed
Context - information about all fields that are predictable and their change patterns sent in the beginning of transmission to allow header compression
In the course of transmission header fields initialized in context do not have to be
transmitted
rohcMaxCidconfigures the maximum number of ROHC contexts used for a data radio bearer in one directionLNCEL; 1,…,16;1; 4
28 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
29 © Nokia Siemens Networks RA41215EN20GLA1
Emergency Call Handling (LTE22)
• Introduces CS Fallback functionality applicable to emergency calls only
• There are two cases:Case 1: UE is idle mode, eNB checks RRC Connection Request for call
establishment cause and in case it is 'Emergency', then a separate admission threshold is used and calls will not be rejected due to capacity license limitations
RRCConnectionEstablishmentRequest, Cause: Emergency
CS Fallback Redirect to UTRAN or GSM
Admission control: AdmittedUE initials an emergency call
actEmerCallRediractivates the feature 'Emergency Call Via Redirection'.LNBTS; Disabled (0), Enabled (1);- ; Disabled (0)
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Emergency Call Handling (LTE22)
Case2: MME is sending CS Fallback Indicator IE with value 'CS Fallback High Priority'
MME
CS Fallback High Priority
MME initials an emergency call
CS Fallback Redirect to UTRAN or GSM
31 © Nokia Siemens Networks RA41215EN20GLA1
Module Contents
• Task of Radio Admission Control
• QoS Architecture and Profiles in LTE
• Default and Dedicated Bearers
• Multiple EPS bearers
• EPS bearers for conversational voice
• ROHC
• Emergency Call Handling
• Radio Admission Control algorithms and thresholds
32 © Nokia Siemens Networks RA41215EN20GLA1
Radio Admission Control
• RL20 RAC checks against operator configurable thresholds– on call establishment:
max_number_of_rrc_connection max_number_of_rrc_connection_emergency_calls (LTE22 supported) max_number_of_active_users max_number_of_active_DRB (LTE7 supported) max_number_of_QCI1_DRB (LTE10 supported)
– on intra-frequency (incoming) handover:
additional offsets can be defined for • time critical handover (event A5)
• handover desired for radio reasons (event A3)
„all or nothing“ – SRB && DRB must be admitted in target cell
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RL20 Admission of SRB1
• RAC compares the number of currently allocated RRC connections in the cell
against following parameter:
• Admission Control criteria for Signalling Bearer:
maxNumRrc
(LNCEL)
Name Range Description
0...840, step 1
Default
240
(420)*
Maximum number of UEs in the cell with an established RRC connection.
Note*: min(ulChBw,dlChBW) is set to value '20 MHz'
Number of currently established RRC connections < maxNumRrc
34 © Nokia Siemens Networks RA41215EN20GLA1
Admission of signaling radio bearer SRB1
if min(ulChBw,dlChBw) has value ' 5MHz' and '10 MHz'- maxNumRrc value range is restricted to 0...480 (default value 240)- maxNumRrc+max(addAUeRrHo, addAUeTcHo) <= 480
if min(ulChBw,dlChBw) has value '15 MHz ' and '20 MHz'- maxNumRrc value range is restricted to 0...840 (default value 420)- maxNumRrc+max(addAUeRrHo, addAUeTcHo) <= 840
addAUeRrHoAdditional # of active UEs, which are allowed to access a cell via handover with HO cause: "HO desirable for radio reasons", when RRC connection (maxNumRrc) or active UE (maxNumActUE) limit already reached.LNCEL; 0...840;1; 15
addAUeTcHoAdditional # of active UEs, which are allowed to access a cell via handover with HO cause: "Time critical handover", when RRC connection (maxNumRrc) or active UE (maxNumActUE) limit already reachedLNCEL; 0...840;1; 20
„0“ implies that no admission priority is granted for UEs accessing the cell via HO
35 © Nokia Siemens Networks RA41215EN20GLA1
RL20 Admission of SRB1 for Emergency Call
• RAC compares the number of currently allocated RRC connections in the cell
against following parameter:
• Admission Control criteria for Signalling Bearer:
Note: maxNumRrcEmergency should be greater than the actual configured threshold maxNumRrc
maxNumRrcEmergency
(LNCEL)
Name Range Description
0...840, step 1
Default
440
(800)*
Maximum number of UEs in the cell which may establish a RRC connection for an emergency call.
Note*: min(ulChBw,dlChBW) is set to value ‚15 MHz‚ or '20 MHz'
Number of currently established RRC connections < maxNumRrcEmergency
36 © Nokia Siemens Networks RA41215EN20GLA1
RL20 Admission of Single non-GBR radio bearer
• As par of the S1AP initial context setup, the bearer management function requests RAC to admit the single non-GBR data radio bearer setup request for UEs for which the SRB1 and SRB2 have been successfully established.
• RAC compares the number of currently UEs with established DRB in the cell against following parameter:
• Admission Control criteria for non-GBR radio bearer:
maxNumActUE
(LNCEL)
Name Range Description
0...840, step 1
Default
120
(240)
Maximum number of UEs in the cell with established DRB.
Note: default 240 for 20MHz
number of currently active UEs < maxNumActUE
37 © Nokia Siemens Networks RA41215EN20GLA1
if min(ulChBw,dlChBw) has value '10 MHz'- maxNumActUE value range is restricted to 0...480 (default value 120)- maxNumActUE +max(addAUeRrHo, addAUeTcHo) <= 480
if min(ulChBw,dlChBw) has value '20 MHz'- maxNumActUE value range is restricted to 0...840 (default value 240)- maxNumActUE +max(addAUeRrHo, addAUeTcHo) <= 840
Admission of single non-GBR radio bearer
addAUeRrHoAdditional # of active UEs, which are allowed to access a cell via handover with HO cause: "HO desirable for radio reasons", when RRC connection (maxNumRrc) or active UE (maxNumActUE) limit already reached.LNCEL; 0...840;1; 15
addAUeTcHoAdditional # of active UEs, which are allowed to access a cell via handover with HO cause: "Time critical handover", when RRC connection (maxNumRrc) or active UE (maxNumActUE) limit already reachedLNCEL; 0...840;1; 20
38 © Nokia Siemens Networks RA41215EN20GLA1
RL20 Admission of Multiple EPS bearers
• The bearer management function requests RAC to admit the data radio bearer setup request for UEs for which the SRB1 and SRB2 have been successfully established.
• RAC compares the number of currently established DRB in the cell against following parameter:
• Admission Control criteria for Multiple EPS bearers:
maxNumActDrb
(LNCEL)
Name Range Description
0...4200, step 1
Default
360
(720)
maximum number of established DRBs in the cell.
Note: default 720 for 20MHz
number of currently established DRBs < maxNumActDrb
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If dlChBw is set to '5 MHz' or '10 MHz'
- maxNumActDrb + max(addNumDrbRadioReasHo, addNumDrbTimeCriticalHo) <= 2400
If dlChBw is set to '15 MHz' or '20 MHz'
- maxNumActDrb + max(addNumDrbRadioReasHo, addNumDrbTimeCriticalHo) <= 4200
Admission of Multiple EPS bearers
addNumDrbRadioReasHoAdditional margin for the maximum number of active DRBs in the cell accessing the cell via HO with HO-cause: "HO desirable for radio reasons“.LNCEL; 0...4200;1; 35
addNumDrbTimeCriticalHo Additional margin for the maximum number of active DRBs in the cell accessing the cell via HO with HO-cause: "Time Critical HO".LNCEL; 0...4200;1; 60
40 © Nokia Siemens Networks RA41215EN20GLA1
RL20 Admission of QCI1 Conversational bearers
• The bearer management function requests RAC to admit the data radio bearer setup request for UEs‘ conversational voice
• RAC compares the number of currently established QCI=1 DRB in the cell against following parameter:
• Admission Control criteria for QCI=1 Conversational EPS bearers:
maxNumQci1Drb
(LNCEL)
Name Range Description
0...200, step 1
Default
100 Max Number QCI1 DRBs (GBRs)
number of currently established QCI=1 DRBs < maxNumQci1Drb
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If dlChBw is set to '5 MHz'
- maxNumQci1Drb + max( addNumQci1DrbRadioReasHo, addNumQci1DrbTimeCriticalHo) <= 150,
If dlChBw is set different to '5 MHz'
- maxNumQci1Drb + max( addNumQci1DrbRadioReasHo, addNumQci1DrbTimeCriticalHo) <= 200
Admission of QCI1 Conversational bearers
addNumQci1DrbRadioReasHo Additional margin for the maximum number of active DRBs in the cell accessing the cell via HO with HO-cause: "HO desirable for radio reasons“.LNCEL; 0...200;1; 15
addNumQci1DrbTimeCriticalHo Additional margin for the maximum number of active DRBs in the cell accessing the cell via HO with HO-cause: "Time Critical HO".LNCEL; 0...200;1; 20
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Radio Bearer Management
• Main feature of RL20 is retrieval and utilisation of UE capabilities in RRM– A Layer 3 RRC signaling procedure
– 3GPP TS 36.306 defines UE capabilities
RRC: UECapabilityEnquiry
eNBUE
RRC: UECapabilityInformation
Ue-RadioAccessCapRequest (eutra)
{(eutra, ueCapabilitesRAT-Container (UE-EUTRA-Capability)), optional UE capabilitities for other RAT types}
43 © Nokia Siemens Networks RA41215EN20GLA1
Radio Bearer Management
• Radio Admission Control may select UL/DL maximum bitrates for a UE:– based on UE capability information received from UE (mbrSelector=0)
– based on O&M parameters maxBitRateUl and maxBitRateDl (mbrSelector =1)
• The maximum Bitrate for a UE in UL and DL for all radio
bearers incl. SRBs are limited to O&M parameter setting:
mbrSelectorLNCEL; 0 (ueCapability), 1 (OaM) ; 0
maxBitRateDlLNCEL; 50…300000kbps;50 ; 170000 Kbps
maxBitRateUlLNCEL; 50…75000kbps;50 ; 50000 Kbps
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Radio Admission Control for intra-frequency HO
• For LTE intra-frequency handover there can be separate admission control
thresholds defined depending on HO trigger cause:
– Time Critical Handover – flag is set when HO trigger is event A5 (urgency is „high“ for coverage handover (event A5))
– Handover Desirable for Radio Reasons – flag is set when HO trigger is event A3 (urgency is „low“ for power budget handover (event A3))
• Better to support the call with Handover rather than rejecting and/or dropping
45 © Nokia Siemens Networks RA41215EN20GLA1
Radio Admission Control for intra-frequency HO
Definition of new admission control threshold for time critical HO:
• HoThreshRrc = maxNumRrc + max(addAUeTcHo, addAUeRrHo)• HoThreshUe = maxNumActUe + max(addAUeTcHo, addAUeRrHo) • HoThreshDrb = maxNumActDrb + max(addNumDrbRadioReasHo, addNumDrbTimeCriticalHo) • HoThreshGbr = maxNumQci1Drb + max( addNumQci1DrbRadioReasHo, addNumQci1DrbTimeCriticalHo)
If NumRRC < HoThreshRrc AND NumActUE < HoThreshUe AND NumActDrb < HoThreshDrb AND NumQci1Drb < HoThreshGbr then
admit HO request in target cell
Otherwise reject HO request for target cell