Sample GPRS Data Network Quality Survey

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GPRS Data Network Quality SurveysSample Report

Last Updated:

November 19, 2003



GPRS Data Network Quality Surveys

Prepared by EnVision Wireless i 19 November 2003

EnVision Wireless Proprietary and Confidential. © Copyright EnVision Wireless, Inc. All Rights Reserved.

Table of Contents

1. Executive Summary ........................................................................................1 2. Test Parameters ............................................................................................ 2 3. Results........................................................................................................ 3 4. Geographic Plots............................................................................................ 9

Index of Figures

Figure 1: RLC Down Link Throughput (kbps)................................................................ 4 Figure 2: LLC Down Link Rate Throughput (kbps) ......................................................... 4 Figure 3: RLC Block Error Rate ................................................................................ 5 Figure 4: RLC Retransmit Block Error Rate ................................................................. 5 Figure 5: RX LEV (in dBm)...................................................................................... 6 Figure 6: RX Quality.............................................................................................6 Figure 7: C Value (dBm)........................................................................................7 Figure 8: Down Link TBF State ................................................................................ 7 Figure 9: Down Link Coding Scheme .........................................................................8 Figure 10: Up Link Coding Scheme ...........................................................................8




Prepared by EnVision Wireless 1 19 November 2003

EnVision Wireless Proprietary and Confidential. © All Rights Reserved.

1. Executive Summary

EnVision Wireless has been contracted by Client to conduct an analysis of their GPRS datanetwork. These studies provide an objective, unbiased view of the quality of service for eachmarket evaluated. This report presents the results for the sample survey conducted in Octoberof 2003.

EnVision Wireless uses the Agilent Nitro Data Test technology to benchmark data service. Thisequipment allows for an accurate, repeatable network evaluation. Results collected in thismethod are useful for comparison at the local level and can also be effectively used tocompare performance on a much larger scale by ranking relative network statistics countrywide to assess regional performance and differences.

In keeping with previous collaborative work between EnVision Wireless and Client, thefollowing parameters were measured during the mobile test:

§ RLC Throughput (kbps) - current data throughput when TBF is open. This value iscalculated, over a one second window, from the RLC ACK/N-ACK on the blocks of data sentand received. The calculation includes retransmission and header bits.

§ LLC Throughput (kbps) - LLC layer measurements gives an indication of the effectiveRLC/MAC throughput and illustrates the impact of RF operations such as cell reselectionson the performance.

§ RLC Block Error Rate - Displays the percentage block error rate for RLC. The values shownare a percentage of the blocks sent on the downlink with bad CRC over the reportingperiod.

§ RX Lev (dBm) - Received power level at the mobile station in dBm. It is decoded directlyfrom the phone data using a simple conversion.

§ RX Quality - The service signal quality on the GPRS downlink. This metric is reported invalues from 0-7 and is measured over a full set of traffic and SACCH frames.

§ C Value (dBm) - The received average carrier level. This value is shown in dBm.

§ Downlink TBF State - Displays the temporary block flow (TBF) status for the Uplink andDownlink. When the temporary block flow is OPEN, the block frame is being transmitted.

When the temporary block flow is CLOSED, the block frame is not being transmitted.

§ Uplink and Downlink Coding Schemes - Displays the coding scheme being used for theUplink and Downlink. The coding schemes are reported as CS1, CS2, CS3, CS4. CS1 offersthe highest data protection and CS4 offers the lowest data protection. As networks are inthe initial turn-on stages, these values may be fixed.

The following table summarizes the overall average results of the survey. For detailed results,please refer to Section 3 of this report.

Table 1: Overall Survey Results

Carrier

RLC

DownlinkThroughput

(kbps)

LLC

DownlinkThroughput

(kbps)

RLCBLER

RLC ReTX

BLER

RX Lev(dBm)

RXQuality

C Value(dBm)

Sample 2.64 2.21 8.61 12.67 -72.12 1.7 -71.26






2. Test Parameters

This section provides a summary of the test parameters used during the project.

Test Parameter Value

Networks surveyed Client GPRS

Hardware used Direct Connect

Handsets used Sagem OT96M

Software used Agilent E6474A

Kilometers surveyed Approximately 200

Drive route selection methodology Highways - A Roads (A2, A10, A4, A16, A13)

Data collection window 7:00 a.m. – 7:00 p.m. daily

Test sequenceWait 30 seconds –> Connect –> Wait 5 seconds –>http://www.google.nl –> Wait 5 seconds ->Disconnect -> Repeat

Drive test vehicle Standard passenger vehicle

Handset location Cradles near headrests

Antenna location Internal

Dates of survey 2 August 2003






3. Results

This section provides the graphical results of the data performance survey. Graphs areprovided for the following metrics:

§ RLC Throughput (kbps)

§ LLC Throughput (kbps)§ RLC Block Error Rate

§ RX Lev (dBm)

§ RX Quality

§ C Value (dBm)

§ Downlink TBF State

§ Uplink and Downlink Coding Schemes






0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0%

20%

40%

60%

80%

100%

120%

Frequency 4601 1542 150 167 111 95 109 38 101 0

Cumulative % 66.55% 88.85% 91.02% 93.43% 95.04% 96.41% 97.99% 98.54% 100.00% 100.00%

0 5 10 15 20 25 30 35 40 More

Figure 1: RLC Down Link Throughput (kbps)

0

1000

2000

3000

4000

5000

6000

0%

20%

40%

60%

80%

100%

120%

Frequency 4959 1198 128 152 120 100 59 71 41

Cumulative % 72.60% 90.13% 92.01% 94.23% 95.99% 97.45% 98.32% 99.36% 99.96%

0 5 10 15 20 25 30 35 40

Figure 2: LLC Down Link Rate Throughput (kbps)






0

500

1000

1500

2000

2500

3000

3500

0%

20%

40%

60%

80%

100%

120%

Frequency 2862 580 312 117 74 92 34 34 161

Cumulative % 67.09% 80.68% 88.00% 90.74% 92.48% 94.63% 95.43% 96.23% 100.00%

0 10 20 30 40 50 60 70 More

Figure 3: RLC Block Error Rate

0

200

400

600

800

1000

1200

1400

0%

20%

40%

60%

80%

100%

120%

Frequency 1143 149 143 305 288 59 17 19 13

Cumulative % 53.51% 60.49% 67.18% 81.46% 94.94% 97.71% 98.50% 99.39% 100.00%

0 10 20 30 40 50 60 70 More

Figure 4: RLC Retransmit Block Error Rate






0

500

1000

1500

2000

2500

3000

3500

4000

4500

0%

20%

40%

60%

80%

100%

120%

Frequency 8 812 1333 3725 4071 2731 1137 52

Cumulative % .06% 5.91% 15.52% 42.38% 71.74% 91.43% 99.63% 100.00%

-105 -95 -85 -75 -65 -55 -45 More

Figure 5: RX LEV (in dBm)

0

500

1000

1500

2000

2500

3000

3500

4000

0%

20%

40%

60%

80%

100%

120%

Frequency 3724 667 806 714 532 388 719 5 0

Cumulative % 67.09% 80.68% 88.00% 90.74% 92.48% 94.63% 95.43% 96.23% 100.00%

0 1 2 3 4 5 6 7 More

Figure 6: RX Quality






0

500

1000

1500

2000

2500

3000

3500

4000

-20%

0%

20%

40%

60%

80%

100%

120%

Frequency 3 5 1342 2836 3531 2218 672 0

Cumulative % .03% .08% 12.73% 39.46% 72.75% 93.66% 100.00% 100.00%

-105 -95 -85 -75 -65 -55 -45 More

Figure 7: C Value (dBm)

Closed

70%

Open

30%

Closed

Open

Figure 8: Downlink TBF State






CS 1

70%

CS 2

30%

CS 1

CS 2

Figure 9: Down Link Coding Scheme

CS 1

61%

CS 2

39%

CS 1

CS 2

Figure 10: Up Link Coding Scheme






4. Geographic Plots

The following geographic plots are attached to this report.

Netherlands

Downlink RLC Throughput (kbps)

Downlink LLC Throughput (kbps)

Downlink RLC Block Error Rate

Downlink Retransmitted RLC Block Error Rate

RX Lev (dBm)

RX Qual

Sample GPRS Data Network Quality Survey

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