tems knowledge sharing

HUAWEI TECHNOLOGIES CO., LTD.

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Huawei Confidential

Security Level:

TEMS Training Manual

Prepared on: 12th Feb 2012

HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

Drive Test overview: In general, Drive Test can be define as a method that used to verify the actual

condition of RF signal certain operator at certain place.

Several functions of drive test :

- Analyzing customer complaint of certain operator in their home or office area

- Finding problem in BTS ( Timeslot Check, TRX Check, Swap Feeder)

- Analyzing the result of optimization process (continuity and all of area)

There are software and equipments can be used for drive test that

installed and connected on laptop.

(i) TEMS Investigation (8.0.3) software with dongle

(ii) 2 TEMS Handsets by Sony Ericsson K800 and k790i with Sims

(iii) GPS by Germin


TEMS = Test Mobile System (Product by Ericsson)

What’s TEMS:

A Test tool use to read and control information sent over the air Interface between

the base station and the mobile station in GSM/cellular system. It can also used for

radio coverage measurement.

Mode of Drive Test:

1- Dedicated / Continuous / Long Call Mode:

In Dedicated Mode first call the drive test number and then start route,ex.

0334- 4355643. To see quality and coverage of the network.

2- Idle Mode:

In Idle Mode the MS is ‘’on’’ but no call occur. To see the coverage of the network.

3- Sequential / Qos / Short Call Mode:

In Sequential Mode first creating the call sequence and then start route, ex.

Create call for 70sec.

4-Scan:

This is one of the TEMS feature, it scan all or selected frequencies on the selected

spot or route. To find the clearest frequency.


“The basic overview of TEMS Investigation (8.0.3)”


How TEMS Works? Several measurement is only available and recorded in idle mode (C1,C2 etc)

Several measurement is only available and recorded in dedicated mode (RxQual,

SQI, FER etc) This is happen because of GSM system network works, not because setting in

TEMS There are several option/feature can be activated by user (force handover, lock

handover etc) which change TEMS measurement behavior

IMPORTANT NOTICE :

In GSM network there are a lot of parameters which change the network behavior,

it is make the network very flexible.

Due to this reason, TEMS has ability to monitor network with parameters on (FULL

mode) and with parameters off (SUB mode) for such as RxLev and RxQual.


Differentiate b/w Full & Sub Measurements:

When using FULL measurement result?

Whenever we want to see BTS parameters settings works at live network

DTX off

When using SUB measurement result ?

Whenever we want to see BTS works without parameters

DTX on

How TEMS measure FULL or SUB measurement?

TEMS record both SUB and FULL measurement at the same time and at the same

log files, it is just need to set what we want to see in reply mode.


GSM Radio Parameters:


GSM Radio Parameters in Dedicated Mode:

Rx Lev (Received-Signal Level):

Level of Received signal strength.

In dBm or Steps. If the value in form of step

substract 110 to the value to get dBm value.

RxLevel is received power level at MS

(maximum RxLevel measured by MS is (±)– 40

dBm.

RXLEV is a number from 0 to 63 that

corresponds to a dBm value range. 0 represents

the weakest signal and 63 the strongest.


RxQual (Receiving-Signal

Quality):

RxQual is a value that

represents the quality of the received

signal. The MS determines the Bit Error

Rate (BER) of the signal and reports it

back to the network. The BER is simply

a percentage of the number of bits it

receives that did not pass error

checking. The bits may have been

garbled along the RF path or lost due to

fading or interference. The higher the

BER the lower the signal quality.

RXQUAL is given as a number from 0 to

7 and represents a percentage range of

BER.


FER (Frame Ensure Rate):

The FER rate is a value between 0 to 100%, and is calculated and

represented in TEMS once each SACCH multiframe (synchronous to the RXQUAL

values). It is (as the RXQUAL) calculated on the TCH and SACCH block.

The FER value presented in TEMS is based on the number of blocks that has

been discarded due to error in the CRC (cyclic redundancy check).

BER Actual:

The BER Actual value is calculated taking DTX into account

and it’s value is based only on blocks actually transmitted & it’s valid for only

voice.

FER Actual:

The FER Actual value is calculated taking DTX into account and it’s value is

based only on blocks actually transmitted & it’s valid for only voice.


SQI:

Speech Quality Index is the

parameter used by TEMS to measure

Speech Quality.

SQI has been designed to

cover all factors that RxQual lack to

measure.

SQI computation considers the

factors: the bit error rate (BER)• the frame erasure rate (FER)• data on handover events• statistics on the distribution of these

parameters

• Furthermore, SQI is updated at

0.5s intervals like RxQual.


C/I Worst/Best{0}:

The carrier-over-interference ratio is the ratio between the signal

strength of the current serving cell and the signal strength of undesired

(interfering) signal components. The C/I measurement function built into TEMS

Investigation enables the identification of frequencies that are exposed to

particularly high levels of interference, something which comes in useful in the

verification and optimization of frequency plans.

The value of carrier-over-interference is 0 to 31

and the greater value is more better it means the interference is low.

MS Power Control Level:

This parameter maintains power to the MS when MS power

decreases.

DTX (Discontinuous Transmittion):

The DTX is a downlink parameter that indicates in percent how

many TCH frame that where not sent to the mobile station during the last SACCH

multiframe. The DTX DL rate varies from 0 to 96%. It can never be 100% since the

at least the frame containing SID information must be sent for each SACCH

multiframe.

The DTX DL rate information element is updated for each SACCH

multiframe.


TA (Timing Advance): TA is to measure the distance of MS from serving cell and it’s Valid for only

in dedicated mode.

RL Timeout Counter[Cur]:

This parameter shows the current value of Radio Link Timeout Counter, ex.

(32, 27, 24,17,9 etc). If the value of RL Timeout counter goes to zero so, call must

be drop.

RL Timeout Counter[Max]:

This parameter shows the Maximum value of Radio Link Timeout Counter, ex.

(32, 64 etc). This value is set by operator depends on it’s network condition. If

network condition is not good so, RL Timeout Counter value sets maximium

because call drop take more time. The value range of this parameter is 0 to 64.


GSM Radio Parameters in Idle Mode:

Note: In dedicated Mode we can collect all

GSM Radio Parameters but in Idle

Mode we only collect Rx Level. In Drive Test we practice to connect

MS1 in Idle Mode and MS2 in

Dedicated Mode.


GSM Current Channels:


Time: It shows the current time same as laptop, ex. 12:02:10.59

Cell Name: It shows the cell name that is present in cell file.

CGI(Cell Global Identity):

CGI is used for cell identification within the GSM network. CGI consist of four

type of information.

CGI = MCC + MNC + LAC + CI

ex. CGI(MCC,MNC,LAC,CI) 041 03 59920 31035

(i) MCC(Mobile Country Code):

Mobile Country Code (3 digits), identifies the country. It follows the

same numbering plan as MCC in IMSI. Ex. 041 (ii) MNC(Mobile Network Code):

Mobile Network Code (2 digits), identifies the GSM/PLMN in that

country and follows the same numbering plan as the MNC in IMSI. Ex. 03


(iii) LAI(Location area Code):

Location Area Code (5 digits), identifies a location area within a GSM

PLMN network. The maximum length of LAC is 16 bits, enabling 59920 different

location areas to be defined in one GSM PLMN.

(iv) CI(Cell Identity):

Cell Identity, identifies a cell within a location area, maximum 16 bits Ex.

31035.

Cell GPRS Support:

This parameter defines that the cell supports GPRS or not.

Band:

It defines that which type of band(900P or 1800P) is using on the cell.

BCCH ARFCN:

It shows the Broadcast Control Channel Number that is dedicated on

the cell.


TCH ARFCN:

It shows the Traffic Channel Number same as BCCH if no hopping occurs.

BSIC(Base Station Identity Code):

BSIC allows a mobile station to distinguish between different neighboring base

stations. BSIC consist of two types of information given below.

BSIC = NCC + BCC

(i) NCC(Network Colour Code):

Network Colour Code (3 bits), identifies the GSM PLMN.

Note that it does not uniquely identify the operator. NCC is primarily used to

distinguish between operators on each side of border.

(ii) BCC(Base Station Colour Code):

Base Station Colour Code (3 bits), identifies the Base Station to help

distinguish

between BTS using the same BCCH frequencies.

Mode:

It define the mode(Dedicated or Idle) of the MS.


Time Slot:

It shows in which time slot the call is established. The total time slot in one

frame is 0 to 7.

Channel Type:

It defines in which types of channels used to estabilished a call.

Note that In Idle mode only BCCH presents or In Dedicated mode combination of

different channels are present ex. TCH/F+ FACCH/F and SACCH/F

Channel Mode:

It defines the speech coding system used in GSM.

(i) Speech Half Rate:

In half rate the bit rate of the codec is 5.6 kbit/s, requires half

the bandwidth of the Full Rate codec, network capacity for voice traffic is doubled,

at the expense of audio quality. It is recommended to use this codec when the

battery is low, it saves 30% energy.


(ii) Speech Full Rate:

In full rate the bit rate of the codec is 13 kbit/s and the network supports

low traffic then half rate.

Speech Codec:

Speech coding is the application of data compression of digital

audio signals containing speech. In GSM AMR used as a Speech Codec.

The Adaptive Multi-Rate audio codec is a patented audio data compression scheme

optimized for speech coding.

There are two types.

(i) AMR Full Rate

(ii) AMR Half Rate

Ciphering Algorithm:

It defines which ciphering algorithm used in GSM network. There are

many ciphering algorithm in gsm but A5/1 is the original A5 algorithm used in

Europe. A5/1 is a stream cipher used to provide over-the-air

communication privacy in the GSM cellular telephone. one burst is sent every 4.615

milliseconds and contains 114 bits available for information.


Hopping Channel:

It shows the call is estabilished on hopping or BCCH.

Hopping frequencies:

It shows the list of hopping frequencies. Ex, h: 559 562 565 568

571 574…

Mobile Allocation Index Offset(MAIO):

It's MAIO that designate the initial position of

frequency - among the frequencies available in MA List, that list with the

frequency hopping.

Hopping Sequence Number(HSN):

It is a number that defines the frequency hopping algorithm or

hopping sequence, and can vary from 0 to 63, ie If HSN is zero, the frequency

hopping sequence is cyclic, ie without changes. If HSN is greater than zero, then

frequencies vary pseudo-randomly.

Note that total 64 hopping algorithms to be used in GSM.


GSM Serving+Neighbors:For Idle Mode: For Dedicated Mode:In Idle mode GSM Serving+Neighbors In Dedicated Mode GSM Serving+Neighbors window shows Cellname, BSIC, ARFCN, window shows Cellname, BSIC,

ARFCN & RxLev, C1 & C2. RxLev.


C1 & C2:

Cell selection refers to the initial registration that a MS will make with a network. This

normally only occurs when the phone powers up or when the MS roams from one

network to another.

C1(Cell Selection):

C1 is the path-loss parameter that is used to determine the strongest cell for selection.

The MS will calculate a C1 for each tower it can see and select the cell tower with the highest

C1.

C2(Cell Reselection):

C2 is the parameter used for cell reselection. Once a MS is camped on a

cell it will continuously monitor the strength of neighbor cells. Every BCCH sends

out a BCCH Allocation (BA) List. This is a list of neighbor cells (ARFCNs) that the MS

must monitor while camped on a particular cell. The MS will monitor these ARFCNs

for signal strength and only reselect a cell that is on this list. The MS will calculate

a C2 value for each cell on the BA list. The cell tower with the highest C2 wins and

the MS will move to that cell and camp on it. Keep in mind the C2 is calculated by

the MS and the MS decides which cell tower to camp on. The cell that the MS

camps on is known as the serving cell. As long as the losing cell and the gaining

cell are both in the same Location Area the MS will not notify the network that is

selecting a new cell.


Message Windows:The message windows are used to list messages and reports received or transmitted by external devices (Layer 2 and Layer 3 messages, mode reports, and error reports with Detail Messages). They are also used to present events generated by TEMS Investigation Data Collection


GSM Data Line Chart Window:


Command Sequence Window:This window is used for create call sequence or SMS sequence such as, (Phone number, Call Duration, Call Type ).


K800 Sony Ericsson Mobile Specifications:


K790i Sony Ericsson Mobile Specifications:


Garmin GPS 20x:The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth. Certain atmospheric factors and other sources of error can affect the accuracy of GPS receivers.


Tektronix Y400 NetTek Analyzer:The Tektronix NetTek Analyzer is a portable BTS field tool. TheTektronix YBA250 test module makes this system for fast identification of base station antenna and transmission line trouble, and easy location of those faults.


Tektronix Y400 NetTek Analyzer

Specifications: Module Support : Connect up to 4 test modules. Display: 26 cm (10.4 in.), 640x480 pixel, transmissive color LCD. Touch screen display optimized for finger use - does not require special

scribes or other tools to operate. Interface Ports: RS-232 serial: 9-pin, up to 115.2 kb/s serial. USB: 1.1 compatible Master & Slave Ports. Keyboard: PS/2 compatible, Mini-DIN connector. Microphone jack: 3.5 mm jack for external microphone. Headphone jack: 3.5 mm jack for external headphone. Built-in speaker. PCMCIA: 2 PCMCIA type II ports. Ethernet Port: Compatible 10Mb. File/Test Storage: Internal memory (standard): 32 MB available for storage and

running Windows CE applications. USB Floppy disk (optional): MS-DOS compatible 3.5", 1.4 MB. PCMCIA Memory card (optional): 128 MB.


Interference Appears:We normally use spectrum analyzer to findout Interference. In below figure shows that the Interference occurs in present band because the Noise Floor increases(it mean any distorted signal present in selected band) i.e, -79.1 dBm and band shift upward. Note that: We consider Interference when band shift continuously upward not in the form of spikes.


Interference Disappears:In below figure shows that the Interference doesn’t occur in present band because the Noise Floor decreases i.e, -111.6 dBm.

Applications of

Tektronix Y400 NetTek

Analyzer : Base Station Transmitter

Analysis Resolve Interference

Problems Troubleshooting of T1

Circuits Base Station Antenna and

Transmission Line Analysis Productivity Enhancement

Software


Jammer:Jammer is a device that produces high frequency distorted signals resulting in Interference and all communication signals are blocked and disturbed with in the range.


Antennas:(i) Yagi Antenna:

A Yagi-Uda array, commonly known simply as a Yagi antenna, is a directional

antenna consisting of a driven element (typically a dipole or folded dipole) and

additional parasitic elements(usually a so-called reflector and one or

more directors). The reflector element is slightly longer (typically 5% longer) than

the driven dipole, whereas the so-called directors are a little bit shorter. This design

achieves a very substantial increase in the

antenna's directionality and gain compared to a simple dipole


(ii) omni-directional antenna:

In radio communication, an omni-directional antenna is an antenna which

radiates radio wave power uniformly in all directions in one plane, with the

radiated power decreasing with elevation angle above or below the plane,

dropping to zero on the antenna's axis. This radiation pattern is often described as

"doughnut shaped". Omni-directional antennas are widely used for radio

broadcasting antennas, and in mobile devices that use radio such as cell

phones, FM radios, walkie-talkies, wireless computer networks, cordless

phones, GPS as well as for base stations that communicate with mobile radios,

such as police and taxi dispatchers and aircraft communications.


Mobile Originating Call Sequence:


Explanation:

The terminal detects a user-originated call. It then accesses the RACH to

send a channel request message. An immediate assignment with the

SDCCH number is sent by the network on the AGCH. The terminal moves

to this channel and the following occurs. The terminal transmits a paging

response message indicating the reason for the specific message (call

setup). The base station responds with an unnumbered acknowledgment

message. An authentication procedure is carried out, as already

described. In a successful event, a ciphering procedure is performed, as

already described. The terminal then sends a setup message. The base

station responds with a call confirmed message followed by an alerting

message in which case the terminal applies the ring-back tone. At the

called party’s call acceptance, the network sends an assignment

command message informing the traffic channel number to be used for

the conversation. The subscriber, still on the SDCCH, responds with an

assignment acknowledgment message and moves to the traffic channel

that has been assigned. The network confirms the acceptance of the call

by the other party by means of a connect acknowledgment message on

the FACCH of the assigned TCH. And the conversation proceeds on the

TCH.


Mobile Terminating Call Sequence:


Explanation: After the mobile initialization procedure, the terminal camps on the PCH.

It eventually detects a paging request message conveying its TMSI. This

impels the terminal to access the RACH to transmit a channel request

message. An immediate assignment with theSDCCHnumber is sent by the

network on the AGCH.The terminal moves toSDCCHand the following

occurs. The terminal transmits a paging response message indicating the

reason for the specific message (response to a paging). An

authentication procedure is carried out, as already described. In a

successful event, a ciphering procedure is accomplished, as already

described. The base station then sends a setup message. The terminal

responds with a call confirmed message followed by an alerting message

to indicate that the subscriber is being alerted. At the subscriber’s call

acceptance, the terminal sends a connect message and removes the

alerting tone. The network responds with an assignment command

message indicating the traffic channel number to be used for the

conversation. The subscriber, still on the SDCCH, responds with an

assignment acknowledgment message and moves to the traffic channel

that has been assigned. The network confirms the acceptance of the call

by the other party by means of a connect acknowledgment message on

the FACCH of the assigned TCH. And the conversation proceeds on the

TCH.


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tems knowledge sharing

Documents

rl timeout

network colour

channel request

connect acknowledgment

assignment

mobile country

mobile network

call confirmed