5 October 2001 End to End Performance Initiative Performance Measurement.
End to End (E)GPRS Performance
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Transcript of End to End (E)GPRS Performance
End-to-End (E)GPRS Performance Improvements BSSG.U. Krause, Com MN PG PLM G1, June 2005
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance ImprovementsOverview
In order to evaluate GPRS performances, the main measurements taken in consideration are:
The GPRS improvements shown herein are related to the performance achieved up to BR8.0
To be noted that:• The statements herein depend on the network configuration, the mobiles, and the network elements used. • Additional delay at the terrestrial Abis interface due to e.g. satellite links, Abis compression affects the packet performance
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput Down Link FTP Throughput
Ping Delay
Round Trip Delay
GPRS PDCH activation
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance ImprovementsGPRS PDCH activation
Down Link FTP Throughput
Ping Delay
Round Trip Delay
GPRS PDCH activation
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements GPRS PDCH activation time
BTSMS BSC
Channel Activation
Time Alignment
Packet Channel Request
First Packet DL Control Block
BR6 BR7
[s]
0.6
0.2
0.4
BR7.0 improvements by• Change the trigger point to start time alignment procedure• Reduction of buffers for each direction in BSC [PPXU only]• Send of the ‘Assignment’ message to MS in advance (parallel processing)BR8.0 improvements by • Optimized evaluation of the Sequence Number to start data transmission
Immediate/Packet Uplink Assignment
Time Alignment
BR8
Optimized improvements with PPXU
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance ImprovementsRound Trip Delay
Down Link FTP Throughput
Ping Delay
Round Trip Delay
GPRS PDCH activation
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements What does mean ‘Round Trip Delay’
MSBSC / PCU
PDAN with Channel Request
PUASProcessing Time
MS-PCU Round Trip Delay (RTD) is intended to be the time interval on the Um interface between
The first Uplink block and the first Packet Uplink Ack/Nack (Contention resolution)
or
The Packet Downlink Ack/Nack (PDAN) with Uplink Request and Packet Uplink Assignment (PUAS)
BTS
RTD
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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In order to reduce the MS-PCU Round Trip Delay time
two types of improvement have been provided
1. The reduction of buffers already treated for ‘PDCH Activation Time’ is valid also to reduce the ‘Round Trip Delay’ time
2. Modified internal PCU communication between processor application and HDLC (only SW modifications on the PPXU card)
GPRS Performance Improvements How to achieve reduced ‘Round Trip Delay’
0
250
Round Trip Delay
BR6.0
BR7.0/BR8.0
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
120200
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance ImprovementsPing Delay
Down Link FTP Throughput
Ping Delay
Round Trip Delay
GPRS PDCH activation
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements What does mean ‘Ping Delay’
PING DELAY is intended to be the delay between the sending of N bytes IP packet to remote host (query) and the receipt of a confirmation response. (measurements based on series of PING)
The following measurements are based on 50 PING series of 32 byte per PING
BTS BSC SGSNIP server
Ping request in uplink
Ping response in downlink
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements Configuration & Parameters
The ‘Ping Delay’ time is strongly dependent on the mobile network components that support the command ‘Ping Request’
TEST CONFIGURATION
SIEMENS SGSN
BSS
Default setting of BSS
Coding scheme GPRS CS2 (PCU frame standard)
LAPTOP
WINDOWS 98
TCP receive window and IP packet size optimized
ME 45/S 45 GPRS MS (4+1) or S55 GPRS MS (4+2)
SUN Ultra 5 with SUN OS 5.8 acting as fixed host
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements Ping Delay Improvements
Apart from the other improvements mentioned before as
Improved buffering structure
Optimized internal communication
additional modifications provide reduced Ping Delay: Modified polling strategy during delayed DL TBF by enlarged fast polling period.
Internal PCU queue is reduced from 3 to 1(or max 2) radio blocks.
Support of the extended uplink TBF mode by open-ended uplink TBF during temporary inactive periods (feature supported by Rel4 MS)
In order to reduce the PING Delay time the BSC supports improvements as follows [PPXU only]:
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements Ping Delay Improvement Values
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
* Depends on MS type (might be reduced by 20ms)
** Value with Extended Uplink TBF (valid for MS re. 4 only, e.g. Prototype SIEMENS S75)
Ping Delay in seconds
0
0,2
0,4
0,6
0,8
1
BR6 BR7* BR8**
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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First PING DELAY is intended to be the delay between the sending of the first ping to remote host (query) and the receipt of a confirmation response (measurements based on one PING)
The resource optimized approach by Siemens distinguished between
Channels are already active (1 and 2 phase access)
Channels are idle (1 or 2 phase access)
Note: Idle channels needed to save radio resources (Um, Abis, and PCU) otherwise up to 4 TS per cell at least and the corresponding network resources have to reserved statically, even if no data traffic has to be transmitted
Test configuration is identical to the measurements for Ping series.
GPRS Performance Improvements First Ping Delay
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements First Ping Delay Improvements
Reduction of sequential PDT/PDCH alignments from three to two. Optimized starting time of the commanded TBF for both active and idle channel
In order to reduce the First PING Delay time the BSC supports improvements as follows [PPXU only]:
Among other improvements mentioned before additional modifications provide reduced First Ping Delay for two-phase access in BR7.0
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements ‘First Ping Delay’ Values
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
* Depends on MS type (might be reduced by 20ms)
** Value with Extended Uplink TBF (valid for MS re. 4 only, e.g. Protoype SIEMENS S75)
First Ping Delay in secondsOne Phase Access
0
0,5
1
1,5
2
2,5
BR6 BR7* BR8**
idle channel active channel
First Ping Delay in secondsTwo Phase Access
0
0,5
1
1,5
2
2,5
BR6 BR7* BR8**
idle channel active channel
Competitor Info:First Ping by Ericsson and Motorola is ~650ms (current solution) for active channel, 1 phase access). Idle channel NOT supported (planned for later releases by Ericsson)!
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance ImprovementsDown Link FTP Throughput
Down Link FTP Throughput
Ping Delay
Round Trip Delay
GPRS PDCH activation
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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Siemens GPRS DL Throughput Performance
GPRS Performance ImprovementsDown Link FTP Throughput (BR7.0)
Kbit/s
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
0
50
100
150
200
250
2 TS MS 3 TS MS 4 TS MS
CS 2
CS 4
MCS9
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance Improvements Down Link FTP Throughput - Configuration & Parameters
The ‘DL FTP Throughput’ time is dependent on the mobile network components.
TEST CONFIGURATION SIEMENS SGSN BSS
Default setting of BSS Coding scheme GPRS CS2 (PCU frame standard)
LAPTOP WINDOWS 98 TCP receive window and IP packet size optimized
SIEMENS S55 GPRS MS (4+2) SUN Ultra 5 with SUN OS 5.8 acting as fixed host
Conditions BERL = 0 (ideal radio condition) FTP download (1000kByte)
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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Currently, the focus on data transfer is mainly related to downlink throughput (DL throughput)
Future application like Mobile-to-Mobile data transfers or MMS exchanges requires higher uplink throughput (UL throughput)
GPRS Performance ImprovementsHow to improve GPRS throughput
BR7.0 Uplink balanced assignment of (E)GPRS resources in order
to distribute automatically resources between Uplink and Downlink during running TBF (e.g. TS 4+1 => 3+2)
Dynamic allocation of the number of uplink and downlink time slots (MS multi-slot classes up to 10)
BR8.0 Balanced Uplink and Downlink during running TBF (e.g. TS
4+1, 1+4) and the use of Extended DL TBF Extended dynamic allocation and support of MS multi-slot
classes up to 12
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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GPRS Performance ImprovementsSimulated Gain of DL FTP Throughput BR7.0 vs. BR8.0
Overview
Performance
Improvements
- PDCH activation
- Round Trip Delay
- Ping Delay
- DL FTP Throughput
20
30
40
50
60
70
80
1000 200 100 50 10 5
FTP Download file size [kbyte]
Data
Th
rou
gh
pu
t [k
bit
/s]
BR7 CS2
BR8 CS2
BR7 CS4
BR8 CS4
Simulation Settings:
(4+1) MS, GPRS CS2 or CS4
BR7.0 Rel. 99 vs. BR8.0 Rel. 4/5 (including extended UL TBF)
GR3.1 Parameters, RecWS = 15 * MSS, MSS = 1460 Byte
115 kbps cable modem, Gb-Bandwidth with 2Mbps
Extended UL TBF boosts Throughput of small File Downloads
by up to 20% (MS dependent) !
Extended UL TBF boosts Throughput of small File Downloads
by up to 20% (MS dependent) !
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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Backup Slides [Performance Tables]
Backup Slides
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COMPARISON of SIEMENS PPCU and PPXU
*) Whole time is less than sum of 3 phases because of parallel Processing, e.g. early Immediate Assignment sending
PPCU/PPXU HW with
BR5.5/6.0
PPXU HW with BR7.0
PPXU HW with BR8.0
GPRS PDCH Channel Activation
80ms 60ms 60ms
Time Alignment Procedure
360ms 140ms 60-80ms
Immediate Assignment
140ms 120ms 120
PDCH bring up Time *)
550 ms 230 ms 150 ms
Backup Slides
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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MS-PCU Round Trip Delay conclusion
120 ms200 ms
MS-PCU Round Trip Delay
PPXU HW withBR7.0/BR8.0
PPCU/PPXU HW with BR5.5/BR6.0
Backup Slides
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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First PING DELAY Table*)
*) Average values; MS type might slightly impact performance
BR6.0 BR7.0 BR8.0
Active Channel, 1 phase access
850 650ms ~600ms
Active Channel, 2 phase access
1050 850ms ~800ms
Idle Channel, 1 phase access
1900ms 1050ms ~800ms
Idle Channel, 2 phase access
2400ms 1150ms - 1250ms
950ms – 1050ms
Backup Slides
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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PING DELAY Table
*) depending on MS type (achieved with NOKIA 6220)
**) BR 8.0 measured with Extended UL TBF (valid only for MS >= Rel.4) depending on MS type (achieved with NOKIA 5140), With fast MS e.g. Prototype Siemens S75
for GPRS (CS2) less than 240ms achievedfor EDGE (MCS6) less than 210 ms achieved
BR5.5 BR6.0 BR7.0*) BR8.0**)
Ping Delay
850ms 720ms 460ms (CS2)
440ms (CS4)
420ms (MCS6)
300ms (CS2)
280ms (CS4)
260ms (MCS6)
Backup Slides
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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Siemens BR 7.0 GPRS DL Throughput Performance
DL Throughput Analysis
(good radio condition, 1 MByte DL)
2 TS MS 3 TS MS 4 TS MS
GPRS CS2 22 kbps 33 kbps ~45 kbps
GPRS CS4 ~26 kbps ~55 kbps ~76 kbps
EGPRS MCS9 ~110 kbps ~164 kbps ~215 kbps
Backup Slides
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PING BR7.0
Backup Slides
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FTP Download / GPRS CS4 / MS-Class 10BR7.0
Backup Slides
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FTP Download / EDGE MCS9 / MS-Class2BR7.0
Backup Slides
© Siemens 2005 End-to-End GPRS Performance BSS commercially not binding
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Measured PING Delay Distribution for 250 successive 32 Byte PINGs
0
20
40
60
80
100
120
200 225 250 275 300 325 350 375 400 425 450 475 500 525 550
PING Delay [ms]
Num
ber o
f PIN
Gs
GPRS CS2 GPRS CS4 EDGE MCS6 GPRS CS2, delayed UL TBF GPRS CS4, delayed UL TBF EDGE MCS6, delayed UL TBF
Gain of the Extended UL TBF
Avg. EDGEPING 260 ms
• Nokia MS 5140 Prototype tested, Rel. 4 compatible, Ext. UL TBF enabled
• With fast Mobile Station e.g. Prototype Siemens S75 less than 210ms achieved
Improvements by Extended UL TBF for Release 4/5 MS BR8.0
Backup Slides
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PING DELAY (50 Pings GPRS CS2)BR8.0
Backup Slides
237ms in average !
Fast MS Prototype Siemens S75Fast MS Prototype Siemens S75
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PING DELAY (50 Pings EDGE MCS6)BR8.0
Backup Slides
200ms in average !
Fast MS Prototype Siemens S75Fast MS Prototype Siemens S75
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NACC in BR8 reduces Cell Reselection Gap BR8.0: Example: FTP download
Backup Slides
Total Gap in Data Transfer is around 600ms to 1200ms depending on MS Type, MS Implementation, UL or DL Traffic (UL GAP is smaller) 1phase or 2phase access Idle / Active Target Cell (PDCH Bring Up / Synchronization required) and Location Area / Routing Area Update required (additional Messages).
Gap from Last Data Block / Packet Cell Change Order in old cell up to Channel Request in new cell is around 260 ms!
Gap from Last Data Block / Packet Cell Change Order in old cell up to Channel Request in new cell is around 260 ms!
New cellOld cell