Sunday, 13 December 2015

The ServiceDRX Configuration and Parameters Related

 The concept of DRX
DRX: Discontinuous Reception
The UE may be configured by RRC with a DRX functionality that controls the UE’s PDCCH monitoring activity. When in RRC_CONNECTED, if DRX is configured, the UE is allowed to monitor the PDCCH discontinuously using the DRX operation specified in this sub clause; otherwise the UE monitors the PDCCH continuously. This saves the uplink resource,
In the RRC_CONNECTED state, if DRX cycle was configured, the UE monitor and receive PDCCH (active period) during duration time; and in the dormant time, UE don’t receives the downlink channel data, to achieve the purpose of power save.
DRX setting and the recommended value
The Pre conditions about DRX configuration 
The parameters of “DRX Switch for GBR” and “DRX Switch for NGBR” should be configured as the network service request.
The parameters in sheet “EUtranCellFDD”.



 Table 61
switchForGbrDrx
switchForNGbrDrx
DRX Switch for GBR
DRX Switch for NGBR
long:0:Close,1:Open;default:0
long:0:Close,1:Open;default:0
R-W-I
R-W-I
0
1
For now, the services provided in most LTE network are NGBR services, so we set the parameter “DRX Switch for NGBR” as “1”.
Service DRX parameters modification range
The service DRX parameters we used in the sheet “ServiceDrx”. Let’s see the properties and structure of service DRX parameters.
For each LTE cell, there are 16 “Service DRX ID”, each of them tagging with a qCI property. The qCI marked by “R-I”, it means these parameters are initial parameters when the eNodeB element creating, and read-only (We discuss the concept of QCI in the following chapters).
So, this means up to 16 groups DRX parameter we should configured.
The configure location is: LTE FDD->E-UTRAN Service Configuration->Service DRX (Service DRX ID)


Table 62
ServiceDrx
description
qCI
shortDrxCycInd
Service DRX ID
MO Description
Label Number of Service Class
UE Short DRX Cycle  Capacity Configuration Indicator
long:[1~9999]
string:[0~512]
long:[1~256];default:1
long:0:No,1:Yes;default:0
RDN
User-Friendly Description of Object, Generated by the System.
QoS class identifier (QCI)
Primary Key
R
R-I
R-I
1
ServiceDrx=1
1
0
2
ServiceDrx=2
1
1
3
ServiceDrx=3
2
0
4
ServiceDrx=4
2
1
5
ServiceDrx=5
4
0
6
ServiceDrx=6
4
1
7
ServiceDrx=7
5
0
8
ServiceDrx=8
5
1
9
ServiceDrx=9
6
0
10
ServiceDrx=10
6
1
11
ServiceDrx=11
7
0
12
ServiceDrx=12
7
1
13
ServiceDrx=13
8
0
14
ServiceDrx=14
8
1
15
ServiceDrx=15
9
0
16
ServiceDrx=16
9
1

Also, we see the same qCI corresponded to two different DRX group. Because of the parameter “UE Short DRX Cycle Capacity Configuration Indicator” is different. The system will identify whether the UE supporting short DRX. If supported, the processing will accord with the short DRX configuration supported in the corresponding QCI. If not, follow to the qCI not support short DRX configuration.
For the mostly current LTE network, the services qCI properties are 6,7,8,9. So the DRX parameters we should configured (Service DRX ID) from 9 to 16.
Recommended value
For each group (Service DRX ID) we have the following parameters recommended.
Table 63
Parameter Name
Short Name
Parameter Explanation
Recommended Value
Long DRX Cycle
longDrxCyc
Long DRX Cycle
320ms
Short DRX Cycle
shortDrxCyc
Short DRX Cycle
80ms
DRX Short Cycle Timer
shortDrxCycT
DRX Short Cycle Timer
2
On Duration Timer
onDuratTimer
On Duration Timer
10ms
DRX Inactivity Timer
drxInactTimer
DRX Inactivity Timer
100ms
DRX Retransmission Timer
drxRetranTimer
DRX Retransmission Timer
8ms
 Solution
 The connections between DRX and QCI The concept of QCI
QCI: QoS Class Identifier
scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc.), and that have been pre-configured by the operator owning the eNodeB. A one-to-one mapping of standardized QCI values to standardized characteristics is captured.
The QoS Class Identifier defined as following:
Table 71
QCI
Resource Type
Priority Level
Packet Delay Budget
Packet Error Loss
Rate (NOTE 2)
Example Services
1
GBR
2
100 ms
10-2
Conversational Voice
2
GBR
4
150 ms
10-3
Conversational Video (Live Streaming)
3
GBR
3
50 ms
10-3
Real Time Gaming
4
GBR
5
300 ms
10-6
Non-Conversational Video (Buffered Streaming)
65
GBR
0.7
75 ms
10-2
Mission Critical user plane Push To Talk voice (e.g., MCPTT)
66
GBR
2
100 ms
10-2
Non-Mission-Critical user plane Push To Talk voice
5
Non-GBR
1
100 ms
10-6
IMS Signalling
6
Non-GBR
6
300 ms
10-6
Video (Buffered Streaming)
TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)
7
Non-GBR
7
100 ms
10-3
Voice,
Video (Live Streaming)
Interactive Gaming
8
Non-GBR
8
300 ms
10-6
Video (Buffered Streaming)
TCP-based (e.g., www, e-mail, chat, ftp, p2p file
9
Non-GBR
9
 
 
Sharing, progressive video, etc.)
69
Non-GBR
0.5
60 ms
10-6
Mission Critical delay sensitive signalling (e.g., MC-PTT signalling)
70
Non-GBR
5.5
200 ms
10-6
Mission Critical Data (e.g. example services are the same as QCI 6/8/9)
Other parameters groups
In ZTE LTE network, there are other parameters groups related with QCI except Service DRX.
Table 72

MO Name
Parameter Name
Short Name
QCI and DSCP Mapping
Label Number of Service Class
qCI
QCI and PBR Mapping
QCI Index
qCI
QoS Service Class
Label Number of Service Class
qCI
Service Prior
Label Number of Service Class
qCI
It’s should be according as QCI when we configure the parameter groups like above tables, QCI is the main key.
 


Budi Prasetyo

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