Catatan Seorang DT-2

Kali ini saatnya belajar tentang Drive Test lagi.
Kenapa pake lagi? Karena sudah pernah belajar
sebelumnya tentunya, melalui training malahan.
Namun, itu dulu, tepatnya CDMA Drive Test
Training. Sekarang, yang ingin di pelajari adalah
drive test (DT) untuk 2G (GSM) dan 3G
(UMTS). Berhubung tools DT nya ga punya,
maka sementara belajarnya melalui tulisan2 yg
beredar di internet dulu dan tetap dengan bantuan
mbah gugel tentunya .

Asessment

Apa itu Rx level = Rx level adalah tingkat kuat level penerima di MS (RENTANG DALAM MINUS dB)MAKIN KECIL NILAINYA MAKIN LEMAH SINYALNYA

APA ITU rX qUAL  = rX QUAL ADALAH tingkat kualitas level penerima di ms (rentang 0-7)makin besar nilainya makin jelek kualitas sinyalnya

Step by Step Cara membeuat Analysis Report

Kadang kita di suruh untuk membuat Report hasil DT  tanpa di beri template / contoh report

kali ini saya akan share bijimana cara membuat report sendiri.

1. Judul : judul dihalaman paling depan itu sanagat penting agar yg nantinya review tidak biangung

2. Tanggal saat melakukan drive test dan Summary  : di isi juga tanggal saat melakukan DT Before dan after , bisanya customer akan kompare hasil DT dengan data performance dari temen2 OSS

3. Buat chart Before dan After, baik chart untuk KPI's or chart number bad Spot.

4. Buatlah kaliamat yeang jelas yang mudah di mengerti orang.

5. Bautlah justifikasi, jika memang di perlukan.

6. buatlah summary jika untuk site audit jika memang ada.

TA and PD (Propagation Delay) counters

The Propagation Delay information are (also) available in simple form of Performance counters.

These types of counters are available in pre-set ranges according to each vendor. The ranges vary from 1 Propagation Delay to several 'grouped' Propagation Delay.

For example in Huawei have some TA ranges in GSM, and other PD ranges in WCDMA (Note: Huawei calls these propagation delay counter s as TP instead of PD). For an 'ideal' scenario, we would have counters for 'each' Propagation Delay.

ARFCN

The Absolute Radio Frequency Channel Number (ARFCN) is a unique number given to each radio channel in GSM. The ARFCN can be used to calculate the exact frequency of the radio channel.

Within the GSM900 band ARFCN 1 to 124 are used. In the GSM1800 band ARFCN 512 to 885 are used. The ARFCNs used in GSM1900 overlap with the ARFCNs used in GSM1800. In GSM1900, ARFCN 512 to 810 are used. A multiband mobile phone will interpret ARFCN numbers 512 to 810 as either GSM1800 or GSM1900 frequencies. The mobile phone will need an additional parameter BAND_INDICATOR to make the correct interpretation.

A complete list of the ARFCNs and the associated radiochannels is given in the table below.

Band	Name	ARFCN	Uplink (MHz)	Downlink (MHz)
GSM400	GSM450	259 ≤ n ≤ 293	450.6 + 0,2×(n-259)	fup(n) + 10
	GSM480	306 ≤ n ≤ 340	479.0 + 0,2×(n-306)	fup(n) + 10
GSM700	GSM750	438 ≤ n ≤ 511	747.2 + 0.2×(n-438)	fup(n) + 30
GSM850	GSM850	128 ≤ n ≤ 251	824.2 + 0.2×(n-128)	fup(n) + 45
GSM900	Primary GSM	1 ≤ n ≤ 124	890 + 0.2×n	fup(n) + 45
	Extended GSM	0 ≤ n ≤ 124 975 ≤ n ≤ 1023	890 + 0.2×n 890 + 0.2×(n-1024)	fup(n) + 45
	GSM Rail	0 ≤ n ≤ 124 955 ≤ n ≤ 1023	890 + 0.2×n 890 + 0.2×(n-1024)	fup(n) + 45
GSM1800	GSM1800 (DCS1800)	512 ≤ n ≤ 885	1710.2 + 0.2×(n-512)	fup(n) + 95
GSM1900	GSM1900 (PCS1900)	512 ≤ n ≤ 810	1850.2 + 0.2×(n-512)	fup(n) + 80

UMTS WCDMA Handover / Handoff

UMTS handover types

Within UMTS it is possible to define a number of different types of UMTS handover or handoff. With the advent of generic CDMA technology, new possibilities for effecting more reliable forms of handover became possible, and as a result one of a variety of different forms of handover are available depending upon the different circumstances.

Ec/Io (and Eb/No)

What is Ec/Io (and Eb/No)?

If someone asks you "Which Signal Level for good call quality: -80 dbm or -90 dBm?"

Beware, if you respond quickly, you might end up missing. This is because the correct answer is ... it depends! The Signal Strength is a very important and essential measure for any technology (GSM, CDMA, UMTS, LTE, etc.). However, it is not the only one: let's talk a little today about another magnitude, equally important: the Signal Noise Ratio.

Equipment , Collection Software And Conclusion

Equipment and Collection Software 

We have spoken enough of them. And what are the equipment and collection software recommended?

Well, that question is not easy. Let's make an analogy: What is the car that you will buy next year?

Got it? You'll have to check what your need, availability in the market, and the best cost benefit. You may even continue by walking.

And with the equipment and software to collect and post-processing of Drive Test is the same.

You should verify if it is compatible with your network, what are the differential costs and benefits, not least, support!

Remember that new tools and features are constantly emerging. Keep up to date on this subject.

Note: we could have listed here some equipment and software, for example, the one we use. But we prefer not to quote any of them, to avoid the risk of eventually being somewhat unfair.

Types of Calls

The Drive Test is performed according to the need, and the types of test calls are the same that the network supports - calls can be voice, data, video, etc.. Everything depends on the technology (GSM, CDMA, UMTS, etc. ...), and the purpose of the test, as always.

A typical Drive Test uses two phones. A mobile performing calls (CALL) for a specific number from time to time, configured in the Collecting Software. And the other, in free or IDLE mode, ie connected, but not on call. With this, we collect specific data in IDLE and CALL modes for the network.

The calls test (CALL) can be of two types: long or short duration.

Short calls should last the average of a user call - a good reference value is 180 seconds. Serve to check whether the calls are being established and successfully completed (being a good way to also check the network setup time).

Long calls serve to verify if the handovers (continuity between the cells) of the network are working, ie calls must not drop.

Types of Drive Test

The main types of Drive Test are :

• Performance Analysis
• Integration of New Sites and change parameters of Existing Sites
• Marketing
• Benchmarking

Tests for Analysis Performance is the most common, and usually made into clusters (grouping of cells), ie, an area with some sites of interest. They can also be performed in specific situations, as to answer a customer complaint.

In integration testing of new sites, it is recommended to perform two tests: one with the site without handover permission - not being able to handover to another site - thus obtaining a total visualization of the coverage area. The other, later, with normal handover, which is the final state of the site.

Depending on the type of alteration of the site (if any change in EIRP) both tests are also recommended. Otherwise, just perform the normal test.

Marketing tests are usually requested by the marketing area of the company, for example showing the coverage along a highway, or at a specific region/location.

Benchmarking tests aims to compare the competing networks. If the result is better, can be used as an argument for new sales. If worse, it shows the points where the network should be improved.

About the Drive Test

What is a Drive Test?

Drive Test, as already mentioned, is the procedure to perform a test while driving. The vehicle does not really matter, you can do a drive test using a motorcycle or bicycle. What matters is the hardware and software used in the test.

• A notebook - or other similar device (1)
• with collecting Software installed (2),
• a Security Key - Dongle - common to these types of software (3),
• at least one Mobile Phone (4),
• one GPS (5),
• and a Scanner – optional (6).

KPI (CDR,CSSR)formulas for different Vendors

KPI (CDR,CSSR)formulas for different Vendors

Huawei:

CDR = (Call Drops on Radio Interface in Stable State (Traffic Channel) + Call Drops on Radio Interface in Handover State (Traffic Channel) + Call Drops due to No MRs from MS for a Long Time (Traffic Channel) + Call Drops due to Abis Terrestrial Link Failure (Traffic Channel) + Call Drops due to Equipment Failure (Traffic Channel) + Call Drops due to Forced Handover (Traffic Channel)) / (Successful TCH Seizures (Traffic Channel)) * 100
CSSR = (Success Rate of TCH Assignment*Success Rate of Call Setup (Immediate Assignment)/10000)*100

ALCATEL:

CDR = Total TCH Drops / [Total TCH Seizures - (Successful HO Out) - (Successful Intracell HO)]= MC736+MC621+MC14c+MC739+MC921c) / ((MC717a + MC717b) + (MC718) - (MC712))

CSSR= SDCCH Assignment Success Rate * TCH Assignment Success Rate or =(1-SDCCH drop rate)*(1-TCH congestion rate)*(1-TCH assignment failure rate)= [1-([(MC138+MC07+MC137)] / [(MC01+MC02)])] * [1-([(MC140a- (MC142e+MC142f)- MC718] / [MC140a- (MC142e+MC142f)])]

ZTE:
CDR=Total TCH Drops / [Total TCH Seizures - (Successful HO Out) - (Successful Intracell HO)]= C11615/[(C11657+C11659+C11921+C11923+C11667)-(C11669)]
CSSR= SDCCH Assignment Success Rate * TCH Assignment Success Rate or =(1-SDCCH drop rate)*(1-TCH congestion rate)*(1-TCH assignment failure rate)=
(1-C11605*100/(C11625+C11696))×(1-(C11610-C11697)*100/(C11609-C11696))×(1-C11657*100/(C11657+C11658))