IS136 Layer 3 Messages ViewIS136 Layer 3 Messages View
To open the IS136 Layer 3 Messages view, select it from the View
menu. This view displays the Common Air Interface messages as they
occur.
Note: In order to log Layer 3 messages, they must be enabled on
the Enable Mask tab in the IS 136 Properties dialog, and the
Primitives check box must also be checked on the Param Mask tab. To
display messages in this view, they must also be selected in the
Properties dialog box for this view. For information about the
Properties dialog box, click the link below.
The following buttons appear at the top of the view.
Pause / Resume: Click this button to halt the display of new
messages. (The button title changes to Resume.) Individual messages
can be decoded by clicking the plus box next to the message. While
the view is paused, click Resume to start displaying new messages
again.
Level 1: While the view is paused, click this button to return
to the undecoded message view. (This is the default when the view
is first paused.)
Level 3: While the view is paused, click this button to decoded
all of the messages that are displayed.
Properties: Click this button to display the Properties dialog
box. Select a channel, then select only the messages that you want
to view.
About the Over Range
Some E6474A Views allow the Agilent receiver to tune to
frequencies over (or under) that which the receiver is specified to
cover. Click the link below for details about this added "over
range
Layer
Definition 1
A logical block in the communication system. There are seven
layers in the ISO/OSI model.
Layer 1
Physical
Layer 2
Data Link
Layer 3
Network
Layer 4
Transport
Layer 5
Presentation
Layer 6
Session
Layer 7
Application
Definition 2
In the Indoor application, MapX allows the user to add detailed
geo set data as layers. Adding layers to a map increases the map
detail, removing layers reduces the map's complexity (detail).
Layer 3 MessageAlso known as Common Air Interface (CAI)
messages, Layer 3 messages report the time, channel (Access,
Paging, Sync, Forward or Reverse), and message type. This value is
typically reported as a hexadecimal data string.
GSM Layer 3 View
This view displays the Layer 3 messages as they occur. To
display this view, click its name under the View menu. Messages can
be decoded while a test is running or being played back, after you
click the Pause button. To select messages to be displayed, see
Properties below.
The following buttons appear at the top of the view.
Pause / Resume: Click this button to halt the display of new
messages. (The button caption changes to Resume.) Individual
messages can be decoded by clicking the plus box next to the
message. While the view is paused, click Resume to start displaying
new messages again.
Level 1: While the view is paused, click this button to return
to the undecoded message view. (This is the default when the view
is first paused.)
Level 3: While the view is paused, click this button to decode
all of the messages that are displayed.
Properties: Click the button to display the Properties dialog
box. Select a channel, then select only the messages that you want
to view.
Examples of message channels are: Broadcast Call Control, Call
Control, Call-Independent Supplementary Services, GPRS Mobility
Management, GPRS Session Management, Group Call Control, Mobility
Management, PDSS1, PDSS2, Radio Resource, and Short Message
Service.
For complete information about the Properties dialog box, click
the GSM Layer 3 Messages View Properties link below.
Configuration
The System Information (1 thru 8) and Paging check boxes on the
GSM Primitives tab in the GSM Properties dialog box must be checked
in order to log and display the messages in this view
About The Over Range
Some E6474A Views allow the Agilent receiver to tune to
frequencies over (or under) that which the receiver is specified to
cover. This added "over range", which usually amounts to
approximately 5MHz added to both the high and low ends of each
link, was not designed to meet the measurement sensitivity
specifications of the receiver. The frequency-to-channel conversion
capability of the software is still allowed to function as normal,
even though no valid channels actually exist in this range. These
non-valid channels provide a sense of how far (in terms of channel
spacing) measurements are being made outside of the specified
frequency range.
Properties - GSM Layer 3 View
The Properties dialog box allows you to control which messages
are displayed in the GSM Layer 3 view. You can also change the text
font and color-code the message types. To open it, click the
Properties button in the GSM Layer 3 Messages view.
This dialog box also enables pop-up views or "message boxes"
that display all of the messages of one type. For more information,
see the Notify Section below.
Note: The selections in this dialog box do not affect the
settings on the GSM Primitives tab of the GSM Properties dialog
box. However, System Information (1 thru 8) and Paging messages
must be enabled on the GSM Primitives tab and in this Properties
dialog box in order to display them in the GSM Layer 3 view.
Filter TabMessage Groups Section
The section contains the following channels: Broadcast Call
Control, Call Control, Call-Independent Supplementary Services,
GPRS Mobility Management, GPRS Session Management, Group Call
Control, Mobility Management, PDSS1, PDSS2, Radio Resource, and
Short Message Service.
Messages Section
This section contains the messages pertaining to the channel
highlighted in the Message Groups section above. Messages selected
in this section can be added to the Filter In section and the
Notify section as described below. Message types are moved to and
from this section.
Filter In Section
This section lists the messages that you will display in the GSM
Layer 3 view. All message types are included in this section by
default.
To remove a message (i.e. filter it out): Select the message in
the Filter In section, then click the < (left-arrow) button in
the upper group. To remove all of the messages from the Filter In
section, click the (right-arrow) button in the upper group. To add
all of the messages to the Filter In section, click the >>
(double right-arrow) button.
Notify Section
You can display up to five Layer 3 message types in separate
pop-up views (message boxes) as they occur. The total number of
message boxes enabled is indicated below the Notify section.
To enable a message box view: Select (highlight) the message in
the Messages section (or hold down the Ctrl key while you select
multiple messages), then click the > (right-arrow) button in the
lower group.
To disable a message box view: Select the message in the Notify
section, then click the < (left-arrow) button in the lower
group. To remove all of the messages from the Notify section, click
the 30K data throughput.
RLC UPlink (TBF ON State)
Lists the uplink count of the throughput values at min, max,
average, and percentage count for 0K and >30K data
throughput.
Reliability Performance Summary
RLC BLER
Displays the RLC BLER found that meets min, max, and average
values. Also displays the percentage count at 0% and >20%.
RLC Downlink Retransmission
Displays the RLC downlink retry rate found that meets min, max,
and average values. Also displays the percentage count at 0% and
>20%.
RLC Uplink Retransmission
Displays the RLC uplink retry rate found that meets min, max,
and average values. Also displays the percentage count at 0% and
>20%.
RF Performance
RxLev (Full)
Displays the Min, Max, Average and % values of RxLev (Full) that
are less than the threshold value set for RxLev.
C-Value
Displays the Min, Max, Average and % values of C-Value that are
less than the threshold value set for C-Value.
Overall Performance Summary
This section of the report provides similar information found in
the executive summary section. However these tables have additional
information and parameters. The parameters provided in this part of
the report are:
Table
Parameters provided
Connection Summary
Attach requests
Attach accepts
Attach completions
Attach success rate
PDP context requests
PDP context accepts
PDP context activation success rate
GPRS Attach Duration
Min, Max, Average
PDP Context Activation Duration
Min, Max, Average
Mobility Statistics
Location update requests
Location update accept
Location update success rate (%)
Routing area update requests
Routing area update accepts
Routing area update success rate (%)
GMM Session State
Idle (%)
Ready (%)
Standby (%)
GMM Attach Session
Attach (%)
Detach (%)
TBF Activity
Downlink - Open, Closed %
Uplink - Open, Closed %
Percentage Coding Scheme Utilization
Downlink - CS1, CS2, CS3, CS4
Uplink - CS1, CS2, CS3, CS4
Percentage Time Slot Utilization
Downlink timeslot allocation 0, 1, 2, 3, 4
Uplink timeslot allocation 0, 1, 2, 3, 4
TFI Assignment
Downlink min, max
Uplink min, max
RLC Mode
Ack
UnAck
RLC Uplink Allocation Mode
Single block
Dynamic
Fixed
No Allocation
Data Transfer Summary
RLC blocks received
LLC frames received
RLC blocks transmitted
LLC frames transmitted
RLC blocks/LLC frames
Receive/Send ratio on RLC and LLC
Throughput Performance Summary
RLC Downlink when TBF is open or closed - Min, Max, Average,
=0K, and >30K
RLC Downlink when TBF is open - Min, Max, Average, =0K, and
>30K
RLC Uplink when TBF is open or closed - Min, Max, Average, =0K,
and >30K
RLC Uplink when TBF is open - Min, Max, Average, =0K, and
>30K
LLC Downlink when TBF is open or closed - Min, Max, Average,
=0K, and >30K
LLC Downlink when TBF is open - Min, Max, Average, =0K, and
>30K
LLC Uplink when TBF is open or closed - Min, Max, Average, =0K,
and >30K
LLC Uplink when TBF is open - Min, Max, Average, =0K, and
>30K
Reliability Performance Summary
RLC BLER - Min, Max, Average, =0%, and >20%
RLC Downlink Retransmission rate - Min, Max, Average, =0%, and
>20%
RLC Uplink Retransmission rate - Min, Max, Average, =0%, and
>20%
LLC Downlink Retransmission rate - Min, Max, Average, =0%, and
>20%
LLC Uplink Retransmission rate - Min, Max, Average, =0%, and
>20%
RF Performance Summary
RxLev (Full) - Min, Max, Average, %, and Threshold limit
C-Value - Min, Max, Average, %, and Threshold limit
Signal variance - Min, Max, Average, %, and Threshold limit
RxQual - Min, Max, Average, %, and Threshold limit
MS output power - Min, Max, Average, %, and Threshold limit
Cell Reselection Interval
Min, Max, Average, Total Reselections
Throughput Analysis
This part of the report provides a series of bar-charts and
scatter diagrams that graphically display the data given in the
previous sections.
The charts include tabular data, cumulative and probability
distribution functions (CDF and PDF). All charts have binned values
based on the thresholds set for the report. The charts provided
are:
RLC downlink throughput
RLC uplink throughput
LLC downlink throughout
LLC uplink throughput
The second part of this section provides information about
throughput and what parameters effect it's performance. These
include:
RLC downlink throughput versus TBF activity
RLC downlink throughput versus Cell Reselection
RLC downlink throughput versus downlink coding scheme and
downlink timeslots allocated
Coding scheme to RLC throughput relation
Timeslots allocated to RLC downlink throughput relation
RLC downlink retry and downlink BLER
RLC downlink throughput, BLER and retry rate
GSM TRAI Reports
This report translates a standard E6474A GSM drive test export
(CSV) file and converts it into a format that complies to Telecom
Regulatory Authority of India (Microsoft Word or HTML format).
http://www.trai.gov.in/
To generate the required reports:
1. Select GSM > GSM TRAI reports
2. Select Import Date File.
This displays the following dialog box. This dialog box lets you
specify report parameters.
The options are:
Group Access Delay - MOC
Group Access Delay - MTC Normal
Group Access Delay - MTC Non Reachable
Call Drop Rate
Voice Quality - Outdoor - Periphery of the city
Voice Quality - Outdoor - Congested area
Voice Quality - Outdoor - Across the city
Voice Quality - Indoor - Office complex
Voice Quality - Indoor - Shopping complex
Voice Quality - Indoor - Other
The following gives a brief description of each component from a
typical GSM phone report.
Group Access Delay (MOC)
This part of the report is a summation of the following parts of
a normal call procedure.
Time to connect calls - This is the time below "service request"
(pressing the send button) and "alerting" (getting the ring-back
tone).
Time to confirm instruction to connect - This is the time
between "call set-up" (initiating the call set-up command) and
"call proceeding" (acknowledged to user).
Time to release call - This is the time between "disconnect
request" (pressing the call end button) and "release complete"
(being passed on to the network).
Time to alert a mobile - This is measured as a mean of two
measurements:
First paging attempt = This is the time between receiving a call
request at PLMN and alerting the mobile.
Final paging attempt = This is the time between receiving a call
request at PLMN and hearing of the "not reachable"
announcement.
Note: It is recommended that you perform at least 10 calls per
week, during your busiest network period from your mobile to the
drive test system. All tests should be spread across all zones of
your network during the course of a quarter.
The Document and HTML formatted reported contains the following
information:
Call Number - a unique ID number
Date
Location called from - estimated text value based on RxLev
values
Layer 3 Message Diagnostics:
Time of service request
Time of call set-up
Time of call proceeding
Time of Alerting
Time of disconnect request
Time of call release
Time to connect call
Time to confirm instruction to connect
Time to release a call
Group Access Delay (MTC)
This report requires you to enter two parts.
PSTN to Mobile to Call
This dialog box lets you enter data parameters that are added to
the database when you select Update.
Select Save to open a saving dialog box. The saved file is
auto-imported into analysis reporter and shown with other imported
data files.
The second part requires you to import a standard GSM drive test
data file.
Call Drop Rate
This report requires you to enter two parts.
Call Drop Rate
This dialog box lets you enter data parameters that are added to
the database when you select Update.
Select Save to open a saving dialog box. The saved file is
auto-imported into analysis reporter and shown with other imported
data files.
The second part requires you to import a standard GSM drive test
data file.
Voice Quality
For valid voice quality reports you must follow these
guidleines:
RxQual samples are to be collected during time consistent busy
hour (TCBH) for the quarter using standard drive test equipment.
(Note: measurements using an engineering handset are not
acceptable).
It is recommended that at least one drive test be conducted
every week during the busy hour, in each of the five location types
(Outdoor - Periphery of city, congested area, across the city;
Indoor - Office and Shopping complex).
The generated report will have the following format:
Route details
Types of Route
Total no. of sample calls
Number of sample calls with voice quality(in RxQual values)
0
1
2
3
4
Outdoor (Periphery of the city)
Outdoor (Congested area)
Outdoor (Across the city)
Indoor (Office Complex)
Indoor (Shopping Complex)
ALL
Drive Test Results
For valid drive test results, the following guidelines should be
followed:
Drive tests should be conducted on at least five routes in each
city. This should be made up from three outdoor and two indoor
tests.
Each report should be accompanied by coverage maps including
color codes for coverage signal strength and voice quality.
Also include hard-copy (print-outs) of any supporting documents
for any other results obtained from the drive test.
The output report table has the following layout:
Outdoor Routes
Indoor Routes
Periphery of the city
Congested Area
Across the city
Office Comlpex
Shopping Complex
Route details
1. Coverage-signal strength
2. Voice Quality
a. Total RxQual Samples
b. RxQual samples with 0-4 values
c. %age samples with good voice quality = (b/a) x100
d. No. of RxQual samples with value 5 or more (a-b)
e. No. of RxQual samples with value 5 or more due to network
coverage
e. No. of RxQual samples with value 5 or more due to
interference
3. Call Success Rate
a. Total Call Attempts
b. Total Calls successfully established
c. Call Success rate (%) = (b/a x100)
%age Blocked calls = 100% - GSR
Call Drop Rate
Handover Data - PCS 1900
Mode: Tracking
Handover data and current serving cell signal data are logged
whenever a handover or channel reselection is observed. Before and
after values for important signal values are logged as well as
information on the handover. Handover Data is viewed in the
Handover Monitor view. This view shows before handoff and after
handoff values, and the change value between the two.
Each handover record contains the following data:
BCCH
BSIC
RxLev
RxQual
Timing Advance
Dist to BTS
Handover form
Handover cause (if available from Layer 3)
BCCHBroadcast Control CHannelA LOGICAL Control channel
continuously broadcasting information about the GSM network, its
parent cell, and the surrounding cells. Always found on TN (Time
Slot Number) 0; supports network to mobile (downlink)
communications only). Range is:GSM1 - 124E-GSM1 - 124 and 975 -
1023DCS1800512 - 885PCS1900512 - 810
BSICBase Station Identity CodeRange = 0 - 77 Octal, 0 - 63
Decimal Octal value is composed of Network Color code, Range = 0 -
7 and Base Station Color Code = 0 - 7
RXLEVReceived Signal Strength LevelThe serving signal strength
level based on the strengths all of the signal bursts (RXLEV full)
or a subset (RXLEV sub) of the signal bursts over a multiframe
period. Range = 0 - 63, representing -110 dBm to -47 dBmBRXLEV -
RXLEV before handoverARXLEV - RXLEV after handoverRXLEV neighbors -
Received Signal Strength Level on neighboring channels
RXQUALReceived signal QualityThe serving signal quality based on
the strengths of all of the signal bursts (RXQUAL full) or a subset
(RXQUAL sub) of the signal bursts over a multiframe period. Range =
0 - 7BRXQUAL - RXQUAL before handoverARXQUAL - RXQUAL after
handover
TAdv (GSM) Timing AdvanceNumber of Bit periods the transmission
burst of a GSM test mobile is advanced to compensate for
propagation delay. Used to ensure that the transmission burst
arrives at the cellsite at the correct time.Range = 0 - 63.
Dist to BTSThe calculated distance to the cellsite based on the
Timing Advance Value1 = 555m, 2 = 1110M, 3 = 1665, etc.
Successful handovers: Handover, Assignment, Immediate
Assignment, Location Update, Channel Re-Selection, Channel Release,
Partial Release or Frequency Redefinition.
Failed handovers: Handover failure, Assignment failure,
Immediate Assignment Rejected, Location Update Rejected, Random
Access Failure or IMSI Detach
Handover CauseLayer 3 message field, specifies reason for change
of channel taking place.
.
GSM Handover Forms and CausesHandover Form messages
Handover
Handover Failure
Assignment
Assignment Failure
Additional Assignment
Immediate Assignment Rejected
Immediate Assignment
Location Update Rejected
Location Update
Random Access Failure
Channel Re-Selection
Frequency Redefinition
Release
Re-establishment
Partial Release
Unknown
Handover Cause Messages
Normal Event
IMIE Not Accepted
Abnormal Release,
UnspecifiedIllegal ME
Abnormal Release, Channel Unacceptable
PLMN Not Allowed
Abnormal Release, Timer Expired
IMSI Unknown in VLR
Abnormal Release, No Activity on the Radio Path
Location Area Not Allowed
Preemptive Release
National Roaming Not Allowed in this Location Area
Handover Impossible, Timing Advance Out Of Range
Network Failure
Channel Mode Unacceptable
Conjestion
Frequence Not Implemented
Service Option Not Supported
Call Already Cleared
Service Option Not Subscribed
Semantically Incorrect Message
Service Option Temporarily Out of Order
Invalid Mandatory Information
Call Cannot Be Identified
Message Type Non-Existent or Not Implemented
Semantically Incorrect Message
Message Type Not Compatible with Protocol State
Invalid Mandatory Information
Conditional IE Error
Information Element Non-Existent or Not Implemented
No Cell Allocation Available
Conditional IE Error
Protocol Error Unspecified
Message Not Compatible with the Protocol State
IMSI Unknown in HLR
Protocol error, Unspecified
Illegal MS
Unknown MM Cause
Unknown RR Cause
GSM Channel Change Monitor View
To display this view, click its name under the View menu.
This view displays the signal parameters before and after a
handover . The handover Form and Cause, Traffic Channels 1 and 2,
Power Class, and the BCCH for neighbors 1 through 6 are displayed,
in addition to many of the same parameters that appear in the GSM
Signal view.
Handoff1) The process by which a cellular mobile is able to move
through a coverage area, handing off from cell to cell in order to
maintain a good signal quality. The handoff is, ideally, not
noticeable to the user. 2) The location at which a call was passed
from one cell site to another.
Note: The Motorola T720 phone does not support data in this
view. If this view is opened for this phone, no data is
displayed.
Form
Cause
LAC
C1
C2
BCCH
BSIC
Cell ID
DTX
RxLev (full)
RxQual (full)
Hop
MAIO
HSN
T Slot
T Ch 1
T Ch 2
Tx Power
TA
PWRC
FER
BCCH
Configuration
The Hand Over check box on the Unsolicited Parameters tab of the
GSM Properties dialog box must be checked in order to log data for
this view.
About the Over Range
Some E6474A Views allow the Agilent receiver to tune to
frequencies over (or under) that which the receiver is specified to
cover. Click the link below for details about this added "over
rangeLACLocation Area CodeThe entire GSM network is subdivided into
small groups of cellsites, each having their own unique code to
help identify smaller geographic areas. As GSM phones move
throughout the network, they can be tracked according to which LAC
they were last reported in. This allows for a more efficient use of
resources since the network only has to send messages to a small
area rather than to the en
C1Mobile calculated uplink quality parameter used in Cell
Selection. Only cells with positive C1 values will be considered
for selection. The mobile will choose the cell with the highest C1
value. C1 is a Phase 1 GSM feature which is used to select a
cellsite to camp on. It is a function of the received signal
strength and the power class of the phone.
tire network
C2C2 is a reselection criteria that is a function of C1. C2 is
further used, once camped on a cell, to select a new cell onto
which to camp. It incorporates hysteresis to avoid bouncing between
cells when a mobile is on a cell boundary. This reduces the number
of reselections normally created at a cell boundary. Many providers
support C1, and some support both C1 and C2.
Cell IdName or numerical value used to uniquely identify each
cellsite or every individual antenna within the wireless network.
Defined on a per network basis.
MAIOMobile Allocation Indication Offset Specifies starting point
for mobile in Frequency hopping sequence
HSNHopping Sequence NumberGSM supports 64 Frequency hopping
sequences ( 1 Cyclic and 63 pseudo-random).
Time Slot1) A uniquely defined increment of time or clock period
in which data is transferred. Each time slot is defined by its
phase position relative to the reference clock (timing) signal. 2)
A multiplexing scheme in which the information from a number of
individual circuits is transmitted over one circuit by allowing
information from each of the individual circuits to be placed on
the common circuit at a particular point (time slot) with respect
to a reference timing signal.
Traffic ChannelThe channel that carriers the voice signal. T Ch
1 is the primary channel; T Ch 2 is the secondary channel.
Traffic ChannelThe channel that carriers the voice signal. T Ch
1 is the primary channel; T Ch 2 is the secondary channel. TX Power
(GSM)The output power level of the mobile or the base station.
Typical levels are 2-19 dBm for GSM, and 2-15 dBm for GSM 1800.
TX Power (GSM)The output power level of the mobile or the base
station. Typical levels are 2-19 dBm for GSM, and 2-15 dBm for GSM
1800.
FERFrame Erasure RateThe number of corrupted or invalid speech
frames per measurement.
Orbitel 907 GSM900 tracking phones report raw FER measurements
from 0 to 24, where 0 = 0% frame erasure, 12= 50%, and 24 = 100%
for full rate channels.
All Sagem GSM phones report FER as a percentage of 0 to
100%.
MCCMobile Country CodeRange = 0 - 999
MNCMobile Network CodeRange = 0 - 99
DSFDownlink Signaling Failure - Actual DSF counter values
between 0 and DSF (Max)DSF Max - Maximum Down Link Signaling
Failure - Network defined upper limit of DSF counterDSF is used to
determine a downlink signaling failure when the phone is in "idle
mode." Every time a CCCH message (Paging Sub-Channel) message is
decoded properly, the DSF counter is incremented by two. For every
incorrectly decoded message, the DSF counter is decremented by
four. If the counter reaches zero, a downlink signaling failure has
occurred.
RLTRadio Link Timeout (GSM)Actual counter values between 0 and
RLT MaxRLT Max - Maximum Radio Link Timeout - network defined upper
limit of RLT counter.RLT is used to determine if a radio link
failure occurred in "dedicated mode." Every time a (SACCH) control
channel message is decoded properly, the RLT counter Is incremented
by two. For every incorrectly decoded message, the RLT counter is
decreased by one. If the counter reaches zero, a radio link time
out has occurred and the call is dropped.
Frequency Hopping
To average the fading conditions found over a range of channels,
the Base Station may use a range of channels over which a call can
be maintained. Frequency hopping reduces the signal-to-noise
ratio.
Frequency ModulationA form of modulation where a change in the
amplitude of the input signal causes a change in the frequency of
the carrier signal.
FSKFrequency Shift Keying A form of modulation where the carrier
signal is varied between two frequencies (representing 1 and 0) in
response to an incoming digital DSP
(Digital Signal Processor) The component in the RF coverage
measurement system that makes general RF measurements as well as
CDMA & GSM specific measurements.
BERBit Error RateThe number of errors, expressed as a fraction
of the total number of bits sent, of a digital signal.
Analog RSSIAnalog Received Signal Strength Indicator
Upper Adjacent ChannelThe signal strength of the upper adjacent
channel in call tracking data. The channel with a number one
greater than the channel being monitored.
Lower Adjacent ChannelThe signal strength of the lower adjacent
channel in call tracking data. Designated as lower with a number
one less than the channel being monitored.
GSM Signal View
This view shows the following call tracking parameters. This
view is used for GSM 900, 1800, 1900, and Dual Band tracking
phones. To display this view, click its name under the View
menu.
The following parameters are displayed in this view. For
definitions, click "Signal Parameters", below.
Mobile State: This field displays the phone state during a test.
The states displayed are:
No Servicephone is not camped on to a network.
Dedicatedphone in a call, camped on to a network.
Idlephone not in a call but camped on to a network.
Serving Cell: This area displays measurement data about the cell
that the phone is currently in. The fields in this area are:
Channel
Displays the broadcast channel in use on the serving cell. If
you right-click the field label the display will change to show the
Cell Name. This name is extracted from the StationInfo.txt file
based on GPS and cell information.
BSIC
Indicates the serving cell base station identity code
(BSIC).
MCC
Displays the Mobile Country Code.
LAC
Displays the Location Area Code. This value is displayed in
decimal units.
Cell ID
Displays a unique hexadecimal number assigned to the serving
cell. This value is displayed in decimal units.
MNC
Displays the Mobile Network Code.
Mobile Measurements: This area displays measurement data about
the Rf interface. The fields in this area are:
TCH
Displays the unique TCH channel number(s) being used by the
phone during a call. When hopping is used during a call, this text
box is empty, and all TCH channels display in the Hopping list.
Tx Level
Indicates the power being used for transmission by the phone.
This is a value from 0-31.
RxLev (F)
Displays the service signal strength (dBm) measured over a full
set of traffic and SACCH frames.
RxLev (S)
Displays the service signal strength (dBm) measured over a sub
set of 4 SACCH and 8 SID (Silence Descriptor) frames.
RxQual (F)
Displays the service signal quality. This will be a value from
0-7 measured over a full set of traffic and SACCH frames.
RxQual (S)
Displays the service signal quality. This will be a value from
0-7 measured over a full set of traffic and SACCH frames.
DTX
Displays the discontinuous transmission state. This can be ON or
OFF
FER
Frame Erasure Rate. The percentage of lost or bad speech frames.
This field is not displayed if frame erasure measurements are not
supported by the attached mobile. Sagem phones report FER as a
percentage. The range is 0 to 100%.
TA
Displays the timing advance being used during a call. This is
given in bit periods and can have a value from 0-63.
TSlot
Displays the timeslot being used by the network during a call.
This can be a value from 0-7.
Type of channel
Displays the logical channel type used
DSF
Displays the actual and network assigned downlink signalling
flag counter.
RLT
Radio Link Timeout Counter. The initial display being the
maximum value as defined by the network. This displays the actual
and maximum values.
Avg C/I
Displays the aggregate carrier to interferer (C/I) value for the
serving channel. It is calculated from the C/I list using the
following method:
Avg C/I = 10 Log ((10 pwr(CI1/10) + 10 pwr(CI2/10) . . . . + 10
pwr(CIn/10))/n)
Frequency Hopping: This area shows all measurement information
related to hopping. The fields displayed are:
Hopping: Displays type of hopping used.
MAIO: Displays the Mobile Allocation Index Offset value.
HSN: Displays the Hopping Sequence Number.
Hops: Display number of hops made during a call.
Hopping List: This list contains the available hopping channels
for the GSM network. The list is passed from the network to the
phone.
Carrier to Interference Hopping List: This area displays lists
of data when hopping is detected and decoded.
ARFCN List: A list of ARFCN channels that are detected (Channel
Numbers).
RxLev List: A list of received signal strengths (dBm).
C/I List: A list of carrier to interference values (dB).
Note: Some of the parameters listed above must be enabled for
collection on the Unsolicited Parameters tab of the Properties
dialog before starting a data collection test.
Channel Display Options
Show Channel Number or Cell-site Name: You can choose to display
either the channel number or the cell-site name. Right-click on the
"Cell" label, then choose Show Name or Show Channel from the pop-up
menu. When you choose Show Name, the "Cell" label changes to
"Name", and the cell-site name, BCCH, and BSIC are all displayed in
the Name field.
Cell-site Name Origin: If you have chosen Show Channel above,
right-click within the CN field, then choose Use Channel, Use
Channel and Qualifier, or Use Cell Id from the pop-up menu to
determine how the Cell-site name is derived.
Description of GSM Measurements
The GSM measurement suite provides complete analysis of the base
station downlink broadcast channel. For each broadcast channel
(BCH), signal quality and strength are measured.
MeasurementDefinition
BSIC
For each BCH found, the base station identity code can be
decoded. This then provides the base station color code (BCC),
network color code (NCC), enabling identification of the cell being
measured.
Channel Number
A range of frequencies or channel numbers (ARFCN) can be
selected for focussed scanning of a particular cell or part of a
network.
Burst power measurement
The measurement is synchronized to the BCH and burst power for
the GSM timeslot is measured. This is used for determining signal
strength for adequate cell coverage. This measurement is carried
out when the BSIC is being decoded.
Fast Power Measurement
When the BSIC is not being decoded, fast channel power
measurements can be made.
Adjacent Channel Analysis
Measurement of the power of two carrier signals (Carrier A and
B) and the power of each of the channels either side of the carrier
(C) signals, that is C-1 and C+1.
Co-Channel Analysis
Measurement of a primary signal, multi-path components and other
components that are not part of that signal. These components being
noise or secondary channels.
ARFCN Absolute Radio Frequency Channel Number(0 to 1023)A
numeric code used to represent a frequency channel in GSM or DCS
networks. The range is:GSM1 - 124E-GSM1-124 and 975 -
1023DCS1800512 - 885PCS1900512 - 810
BCCHBroadcast Control CHannelA LOGICAL Control channel
continuously broadcasting information about the GSM network, its
parent cell, and the surrounding cells. Always found on TN (Time
Slot Number) 0; supports network to mobile (downlink)
communications only). (0 to 1023)Range is:GSM1 - 124E-GSM1 - 124
and 975 - 1023DCS1800512 - 885PCS1900512 - 810
BSICBase Station Identity CodeRange = 0 - 77 Octal, 0 - 63
Decimal Octal value is composed of Network Color code, Range = 0 -
7 and Base Station Color Code = 0 - 7
C1Mobile calculated uplink quality parameter used in Cell
Selection. Only cells with positive C1 values will be considered
for selection. The mobile will choose the cell with the highest C1
value. C1 is a Phase 1 GSM feature which is used to select a
cellsite to camp on. It is a function of the received signal
strength and the power class of the phone.
-64 to+64
C2C2 is a reselection criteria that is a function of C1. C2 is
further used, once camped on a cell, to select a new cell onto
which to camp. It incorporates hysteresis to avoid bouncing between
cells when a mobile is on a cell boundary. This reduces the number
of reselections normally created at a cell boundary. Many providers
support C1, and some support both C1 and C2. -64 to +64.
Carrier PowerThe received power of the current channel derived
from the receiver. Similar to Rx Power derived from the tracker.
-120 to -20.
Cell IdName or numerical value used to uniquely identify each
cellsite or every individual antenna within the wireless network.
Defined on a per network basis. 0 to 65535
DSFDownlink Signaling Failure - Actual DSF counter values
between 0 and DSF (Max)DSF Max - Maximum Down Link Signaling
Failure - Network defined upper limit of DSF counterDSF is used to
determine a downlink signaling failure when the phone is in "idle
mode." Every time a CCCH message (Paging Sub-Channel) message is
decoded properly, the DSF counter is incremented by two. For every
incorrectly decoded message, the DSF counter is decremented by
four. If the counter reaches zero, a downlink signaling failure has
occurred. 0 to 45.
DSF(max)Downlink Signaling Failure - Actual DSF counter values
between 0 and DSF (Max)DSF Max - Maximum Down Link Signaling
Failure - Network defined upper limit of DSF counterDSF is used to
determine a downlink signaling failure when the phone is in "idle
mode." Every time a CCCH message (Paging Sub-Channel) message is
decoded properly, the DSF counter is incremented by two. For every
incorrectly decoded message, the DSF counter is decremented by
four. If the counter reaches zero, a downlink signaling failure has
occurred.
FERFrame Erasure RateThe number of corrupted or invalid speech
frames per measurement.
Orbitel 907 GSM900 tracking phones report raw FER measurements
from 0 to 24, where 0 = 0% frame erasure, 12= 50%, and 24 = 100%
for full rate channels.
All Sagem GSM phones report FER as a percentage of 0 to
100%.
Hopping FlagIndicates whether frequency Hopping currently
enabled on network.(0,1)
Hopping List The list of channels the phone can utilize during a
call.
Hopping Sequence Number The pattern that the Absolute Radio
Frequency Channel Numbers in the Mobile Allocation Table follow. 0
to 63
LACLocation Area CodeThe entire GSM network is subdivided into
small groups of cellsites, each having their own unique code to
help identify smaller geographic areas. As GSM phones move
throughout the network, they can be tracked according to which LAC
they were last reported in. This allows for a more efficient use of
resources since the network only has to send messages to a small
area rather than to the entire network.(0 to 65535)
Lower Adjacent ChannelThe signal strength of the lower adjacent
channel in call tracking data. Designated as lower with a number
one less than the channel being monitored.(-120 to-20)
MAIOMobile Allocation Indication Offset Specifies starting point
for mobile in Frequency hopping sequence.(0 to 63)
. RLTRadio Link Timeout (GSM)Actual counter values between 0 and
RLT MaxRLT Max - Maximum Radio Link Timeout - network defined upper
limit of RLT counter.RLT is used to determine if a radio link
failure occurred in "dedicated mode." Every time a (SACCH) control
channel message is decoded properly, the RLT counter Is incremented
by two. For every incorrectly decoded message, the RLT counter is
decreased by one. If the counter reaches zero, a radio link time
out has occurred and the call is dropped. (0 to 64)
RLT(max)Radio Link Timeout (GSM)Actual counter values between 0
and RLT MaxRLT Max - Maximum Radio Link Timeout - network defined
upper limit of RLT counter.RLT is used to determine if a radio link
failure occurred in "dedicated mode." Every time a (SACCH) control
channel message is decoded properly, the RLT counter Is incremented
by two. For every incorrectly decoded message, the RLT counter is
decreased by one. If the counter reaches zero, a radio link time
out has occurred and the call is dropped.
Time Slot1) A uniquely defined increment of time or clock period
in which data is transferred. Each time slot is defined by its
phase position relative to the reference clock (timing) signal. 2)
A multiplexing scheme in which the information from a number of
individual circuits is transmitted over one circuit by allowing
information from each of the individual circuits to be placed on
the common circuit at a particular point (time slot) with respect
to a reference timing signal.(0 to 7)
Timing AdvanceNumber of Bit periods the transmission burst of a
GSM test mobile is advanced to compensate for propagation delay.
Used to ensure that the transmission burst arrives at the cellsite
at the correct time.Range = 0 - 63
TX Power (GSM)The output power level of the mobile or the base
station. Typical levels are 2-19 dBm for GSM, and 2-15 dBm for GSM
1800.(2 to 19)
Upper Adjacent ChannelThe signal strength of the upper adjacent
channel in call tracking data. The channel with a number one
greater than the channel being monitored.(-120 to -20)
BERBit Error RateThe number of errors, expressed as a fraction
of the total number of bits sent, of a digital signal.
Band The scanned frequency for which signal strength data is
listed in iDEN, GSM, and PDC data collected using a broad-band
scanning receiver
Analog RSSIAnalog Received Signal Strength Indicator
Aggregate Power
Aggregate is the measure of the spreading of a signal over time
due to multipath and low signal noise. In the process of
correlation, as the point of maximum correlation is approached, the
power is above the noise. Aggregate power is a measure of the power
to either side of the peak and above the noise. If the aggregate
power is greater than the peak power, multipath is indicated.
Adjacent Channel
You can make adjacent channel power measurements. This
measurement will return the ratios of the power at the carrier
frequency and that of the power of a channel either side.
Up to two carriers can be selected and displayed.
The power levels depend on the offset used. One channel offset
(200 kHz) means interfering signal is transmitted at a level 9 dB
above that of the desired signal, and a two channel offset (400
kHz) means that the signal is transmitted at a level 41 dB above
the desired signal.
Blocked CallA call that the cellular network did not assign to a
voice or traffic channel within a specified time because of network
faults or for lack of available capacity.
L-Band
The portion of the signal spectrum that includes frequencies
from 390 MHz to 1550 MHz. The GPS carrier frequencies (1227.6 MHz
and 1575.42 MHz) are included in the L-band.
Band:
Band: -1
Band: DCS1800
Band: GSM900
Band: IS-136/850
Band: IS-136/1900
Band: IS95
Band: J-CDMA
Band: J-STD-007
Band: J-STD-008
Band: K-CDMA
This keyword specifies the wireless band to be used for correct
proper channel / frequency correlation. The value set by Band is
persistent: it will remain in effect until another Band statement
is encountered. The initial value for Band is -1 which implies "not
specified." If Band is specified AND the phone supplies a Band
value, it will be used in conjunction with channel (if specified)
to match cell sites.
Statistics Menu
Calls are categorized and counted as follows. Click (to check)
next to each call category to show or hide it. A check mark next to
the item indicates that it is displayed.
Total - This shows the total number of calls made during the
test.
Good calls - This shows the total number of calls for which no
problem was observed and the user-defined signal thresholds were
not exceeded.
Blocked calls - This shows the total number of calls that the
cellular network did not assign to a voice or traffic channel
within a specified time because of network faults or for lack of
available capacity.
Dropped calls - This shows the total number of calls that ended
before expiration of the call duration timer due to signaling or RF
problems.
No Service calls - This shows the total number of calls that
could not be placed or completed due to the loss of network
service.
No Comm This shows the total number of "No Comm" calls. If a
call is ended by the software and the phone does not react to the
End key command, the next time the software instructs the phone to
place a call, it will find it unavailable. The failed attempt is
also classified as No Comm. This type of No Comm can occur with
E6473A systems. An example of a reason a call is classified as a No
Comm is Rx Burst Timeout .
MPIO - My Phone Is Off. This shows the total number of calls
made to another phone in the data collection system that were not
answered. (The called phone was never assigned a Voice
channel.)
Progress - A message indicating the call progress is displayed
in this field. Possible messages are: Initializing, Idle, Dialing,
Setup, On Call, and Continuous Call. In addition to the messages,
count-down values are displayed for Initializing, Idle time, Setup
time, and On Call time. The count for each phase starts with the
Call Duration, Idle Time, and Call Setup values entered on the
Autodialing tab of the phone's Properties dialog box. When a test
is started, "Initializing" is displayed, with an initial value of
30.
Setup - This indicates the time period between the time the
phone number is dialed and the time the phone is assigned a Voice
channel.
Breakdown - This indicates the time period between the time the
END key is pressed and the time the phone is assigned a Control
channel.
Power Measurements
The system is capable of measuring power using various methods.
The following list describes how the techniques used, are
calculated and displayed.
Spectrum and CW analyzer
RMS power measurement.
Channel analyzer
Total channel power.
Broadcast channel and adjacent channel analyzer
Power averaged over 8 timeslots.
Broadcast channel with BSIC decoding
Power is measured over 1 timeslot.
Co-channel analyzer
Power of the dominant component measured over 11 frames.
RxLev_Access_Min
Minimum received level at the mobile required for access to the
system.
These values are sent on the BCCH by the base station on the
layer 3 and 4 messages
Properties - GSM Layer 3 View
The Properties dialog box allows you to control which messages
are displayed in the GSM Layer 3 view. You can also change the text
font and color-code the message types. To open it, click the
Properties button in the GSM Layer 3 Messages view.
This dialog box also enables pop-up views or "message boxes"
that display all of the messages of one type. For more information,
see the Notify Section below.
Note: The selections in this dialog box do not affect the
settings on the GSM Primitives tab of the GSM Properties dialog
box. However, System Information (1 thru 8) and Paging messages
must be enabled on the GSM Primitives tab and in this Properties
dialog box in order to display them in the GSM Layer 3 view.
Filter TabMessage Groups Section
The section contains the following channels: Broadcast Call
Control, Call Control, Call-Independent Supplementary Services,
GPRS Mobility Management, GPRS Session Management, Group Call
Control, Mobility Management, PDSS1, PDSS2, Radio Resource, and
Short Message Service.
Messages Section
This section contains the messages pertaining to the channel
highlighted in the Message Groups section above. Messages selected
in this section can be added to the Filter In section and the
Notify section as described below. Message types are moved to and
from this section.
Filter In Section
This section lists the messages that you will display in the GSM
Layer 3 view. All message types are included in this section by
default.
To remove a message (i.e. filter it out): Select the message in
the Filter In section, then click the < (left-arrow) button in
the upper group. To remove all of the messages from the Filter In
section, click the (right-arrow) button in the upper group. To add
all of the messages to the Filter In section, click the >>
(double right-arrow) button.
Notify Section
You can display up to five Layer 3 message types in separate
pop-up views (message boxes) as they occur. The total number of
message boxes enabled is indicated below the Notify section.
To enable a message box view: Select (highlight) the message in
the Messages section (or hold down the Ctrl key while you select
multiple messages), then click the > (right-arrow) button in the
lower group.
To disable a message box view: Select the message in the Notify
section, then click the < (left-arrow) button in the lower
group. To remove all of the messages from the Notify section, click
the Options, Other tab.
Threshold
Select to change the number of measurement results displayed.
Only the measurements with a result greater than or equal to the
threshold value will be displayed. For bar chart displays only.
This may reduce the number of measurement results displayed.
Description
The Interference Analyzer view measures the power of a serving
channel and the upper and lower adjacent channels. This function is
primarily intended for use in systems with Agilent E6474A option
220. Typically, the carrier frequency of the adjacent channel
interference measurement is linked to the serving channel of the
phone. When the phone is handed-off to a new channel, the adjacent
channel interference measurement tunes to the new channel.
The Interference Analyzer interference measurement can also be
used independently from the phone. A user can define a specific
channel to measure along with the associated upper and lower
adjacent channels.
Adjacent channel interference may arise from other cells/sectors
in the network. Two independent adjacent channel interference
measurements are provided in a single view. This is intended for
two phone configurations. Each adjacent channel interference
measurement can be linked to one of the phones.
.
Overview of GSM Interference Analyzer View
The Interference Analyzer provides measurements of both Adjacent
Channel and Co-Channel interference.
Adjacent channel interference may arise from other channels in
the same cell or from neighboring cells.
Co-Channel interference may arise from base stations in
neighboring and more distant cells using the same frequency as the
current channel. If the network is set up correctly, neighboring
cells should not re-use the same channels.
The total signal power at the antenna of a phone can be composed
of combinations of the following components:
Direct path signal (primary)
Short multi-path components (short fading)
Long multi-path components
Co-channel components
The direct path signal is defined as the signal arriving from
the base station by the most direct path.
Short fading components are signal components that might have
reflected from nearby objects and are delayed from the direct path
component by less than 1 symbol period.
Long path components are signal components that have reflected
from more distant objects such as hills and mountains and are
delayed from the direct path component by greater than 1 symbol
period. The co-channel component is a signal received from a
secondary signal source transmitting on the same frequency as the
primary signal. Click here for a diagram.
In an ideal environment there would be no co-channel signal and
no multi-path components. In this situation the received signal
strength from the primary base station would be constant at a given
location and would decrease with distance from the base
station.
In typical real life situations this is not the case. Each of
the signal components combines to produce a signal that varies over
short distances. As a phone moves over even relatively short
distances the angle of incidence of the short fading components
changes by a greater amount that for long fading components. This
results in changing phase and amplitude relationship for each of
the components.
The receiver samples 11 frames of the GSM signal. Sampling 11
frames ensures that the sampled data will always contain an FCH/SCH
sequence of the GSM BCH. The sample rate is such that the
relationship for individual samples is quasi-stationary, however
over the 11 frames of sampled data the vehicle will have moved a
short distance and the sampled signal will show the characteristics
of all contributing signal components. See this diagram for the
resultant signal trend.
In order to analyze the received data and make measurements of
the signal components we must first find a reference point within
the sampled data. This is done using standard techniques to find
the FCH/SCH pattern within the sampled data. Having found the
FCH/SCH the sampled data is adjusted to correct for carrier and
symbol lock. The received data is filtered and peak detected to
estimate the trend of the direct path and short fading
components.
The key to analysis of the signal components is the
constellation pattern produced by GMSK modulated signals such as
GSM. Once the sampled data has been symbol locked we are able to
analyze the constellation pattern for the middle 48 bits of the SCH
mid-amble.
For an ideal signal with only a direct path component it is
possible to rotate each point on the constellation such that each
point lines up at a single reference position. Rotating the vectors
to a reference position in the presence of short fading results on
this sort of graph . The direct path vectors align but there is a
small variation in the alignment of the short path components due
to the change in these components over the period of the 48
symbols. This results in a smear of the short path vector. The path
of the resultant vector is the signal trend arising from the direct
and short path components.
The co-channel and long path components appear uncorrelated with
the primary and short path components and would be shown on the
constellation diagram as a constellation around the resultant
vector.
This diagram shows the impact of co-channel and long path
components on the constellation diagram. In practice the
constellation for long-path and co-channel components will describe
a circle around the resultant vector due to the rotation applied to
each point to align the direct path components.
Long path components are time shifted images of the direct path
signal. A correlative modeling technique is used to construct the
best fit for the long path components. The Agilent E7475A
application uses this data to graphically show the delay spread of
long path components. This data can now be removed from the signal
data leaving only direct, short and co-channel components.
Short path components can be removed by analyzing the smeared
vector component resulting from the short path. Each short path
vector is removed by applying an equal amplitude component out of
phase by 180 degrees.
The final stage of the analysis is to remove the direct path
component. This is done by moving the constellation to the origin.
The co-channel signal is now left as a ring around the origin.
Applying the reverse rotation to that applied to each point in the
earlier stages returns the constellation points to their correct
position allowing analysis of the co-channel component.
The GSM Interference Analyzer view presents the following
results:
Total Power
Primary Power
Fading (Short path)
Primary/Interferer
Primary BSIC and cell name
Secondary BSIC and cell name
The delay spread results are presented graphically.
All of the above results are logged in the system database along
with the geographic location of the measurement. The results can be
replayed within the application or can be exported to GIS
post-processing software for in-depth geographic analysis.
GSM Phone Reports
The following gives a brief description of each component from a
typical GSM phone report.
Executive SummaryCall Statistics Chart and Details
This chart and table shows calculations and statistical analysis
of call performance during the drive test. All the calculations are
based on GSM Layer3 message analysis (except for Total RF
drops).
Total RF Drops refers to number of times the radio link
counter's current value reached zero.
Quality Performance Summary
This table is a summary of some critical quality parameters,
which are listed showing Min, Max, and Average values for critical
quality parameter values.
The table also shows a percentage exceeding-threshold
calculations. These thresholds are defined in the thresholds
settings.
Certain parameters do not have Min, Max, and Average values.
This is because these are textual state values. The hopping
parameter shows in average column Hop, which is actually the mode
of TCH State.
N1_Rxlev and N2_Rxlev, refers to the first and second strongest
neighbor channels Rxlev.
Note: The calculations for greater and less () are not
changeable in this current release.
Overall Performance Summary ReportPhone Call State
This chart is a simple Histogram of the three possible phone
states reported by the Phone. This chart is useful in getting an
idea on what was the phones activity during the drive test. For
example if the Phone was Idle for the most of times(example: 98% ),
then the RxQual and other Dedicated mode parameters which were
reported in the remaining very low (2 %) Dedicated state really
does not add much value.
DTX State
This chart shows the uplink DTX state as reported by the
phone.
Hopping State
This is a useful chart to be used in correlating the quality
parameters with the channel assignment and network
configuration.
Hopping is expected to improve the performance of the network,
therefore if the Hopping percentages are high, it means that the
calls are mostly maintained on Hopping channels. If quality is bad,
then either Hopping parameters or RF needs optimisation.
RxQual Sub
This is a histogram chart of RxQual_Sub, the chart shows values
over all possible discrete values of RxQual_sub (ranging from 0 to
7). RxQual_sub is a prime indicator of air interface quality of
communications.
FER
This chart shows FER.
Very high values could be expected in higher FER bins. This is
can be due to the fact that FER is reported by the phone as Full
(that is measured over all speech frames). If DTX is in use, and
depending on speech coming in , there could be several DTX ON
states. This can result in high FER.
If DTX is used in the network, it is recommended not to rely on
this parameter, other than for exceptional cases where the
information used for testing (like some varying Music) ensured that
DTX state is never turned ON.
RxLev Full and RxLev Sub chart
This chart shows both Rxlev_full and Rxlev_Sub.
Rxlev_Sub is used in dedicated mode when the DTX is ON. If DTX
is not ON, Rxlev_sub will be same as Rxlev_full.
Rxlev_Full can not be relied upon if DTX ON in dedicated mode.
However for Idle mode Rxlev_Full it is a useful parameter for
getting coverage indications. During dedicated mode, both
Rxlev_Full and Rxlev_Sub are subject to Downlink power control.
Tx Power (dBm)
This chart shows Tx Power, by plotting TxLev (and not absolute
power values).
The values along the bottom of the chart indicate higher
transmit power. If there are high percentages found, then the phone
was transmitting at higher power.
This can result in higher probability of Uplink interference
generation for other users, and since the Tx Power levels are
controlled by the cell, a higher level of Tx Power also indicates
poor uplink quality.
Timing Advance
This chart shows Timing Advance values. Each integer indicates
an RF Propagation distance between the phone and the cell as
approximately 550m.
As the value gets higher, it indicates that the phone was
communicating with the cell from very large distance.
There could be several reasons behind getting higher value
percentages:
Cell Dragging
Poor Coverage
Repeater
Cell Overshoot
These problems and their diagnosis can be done, to a certain
extent, by using other charts and analysis table in this
report.
RLTC Current Values Changes
This is not a cChart of simple RLTC values. It is a histogram of
probability of RLTC value changes.
The RLTC counter in GSM controls the RF abnormal release process
(Drop calls). RLTC is assigned a max value which is maintained by
the phone in dedicated mode. If the phone is not successful in
decoding a SACCH block, it decrements the RLTC counter by 1, if it
is successful in decoding it increments by 2, but not exceeding the
absolute current value greater than the max value.
This chart displays the difference between the RLTC max value
and the current value for every reported sample from the phone.
If the difference is 0 then it means the SACCH blocks are
getting decoded, as the difference value increase, we know that the
current value is decrementing. This indicates the severity in
received quality.
In this chart, a large percentage will be expected for 0,
similarly to the right of the chart, for values in the range of 10
and above, means that the counter decremented by 10 from its
current value. This indicates the consistency in the bad
quality.
This type of calculation gives you a very good indication of RF
quality severity under varying conditions of RLTC max values.
DSF Current Value Changes
Similar to the RLTC current value changes chart, this chart
represents the DSF (Downlink Signalling Failure) parameter, which
decrements by 4 and increments by 1 for every unsuccessful and
successful decode of paging message in the IDLE Mode.
If the DSF counter changes, this indicates the number of Paging
Blocks which were missed by the phone and hence the quality in the
Idle Mode. The calculation for this chart is similar to the RLTC
current value changes.
Call Quality Analysis ReportRxLev and RxQual variations
This is a snapshot analysis to see the impact of RxLev on
quality. You should focus on the chart areas where RxQual is poor,
and then see what was the RxLev variations around these poor RxQual
areas. This indicates where poor quality is due to interference or
coverage issues.
RxQual (Sub) versus RxLev (Sub)
This is an X-Y view of the RxLev and RxQual relationship.
For higher values of RxLev on the x-axis, lower and almost 0
values of RxQual can be expected. For higher values of RxLev,
higher RxQual values are seen. This indicates that this network (or
this drive area) is prone to interference.
Uplink Performance Estimation
The cell controls the phone transmit power, and this control is
based on two parameters:
Uplink Received Signal Level
Uplink Received Signal Quality
Ideally the RF link should be balanced for Gains/Losses and
hence any change in the Downlink receive level should effect the
same kind of Signal level change in the Uplink.
This means if the Downlink Signal level is good, the Uplink
Signal level should also be good and hence if Downlink Quality is
good, the Uplink should also be good. This occurs when the Tx Power
is low (as per the power control algorithm).
For good signal level, a high amount of Tx Power is seen. This
means the Uplink quality is bad despite of good signal level, which
means probability of interference.
Therefore this chart correlates the Downlink received level to
Uplink transmitted power, indicating the probability of
interference in the Uplink. In certain networks, due to improper
settings and control at the cells, the phone always starts with
high power level transmission after every handover as is commanded
to the phone in the handover command message.
Distance to Coverage
This chart shows the relationship between distance and
coverage.
Ideally as the distance increases the coverage should
proportionately decrease based on terrain data.
However there could be instances where depending on conducting
bodies like water, low absorbing reflector, or higher altitudes,
you can get good signal lever at larger distances. This helps when
we analyze what kind cell balancing is there in the network.
Quality to Handovers (EGSM)
The above three charts for Quality to Handovers are similar. The
only difference is that the secondary axis parameter, BCH, is split
into three ARFCN bands:
P-GSM
E-GSM
DCS-1800
This is done so that the BCH changes become visible on the
chart. If all the BCH values are plotted one chart, and with the
ARFCN range from 1 to 1024, scaling becomes an issue.
These charts plot the BCH value against RxQual_Sub. Any change
in BCH value indicates a Handover (in dedicated mode) and a Cell
Reselection (in Idle Mode).
You can see for Handover points (where BCH changes) and what the
RxQual was at that point.
Quality to BCCH (GSM) and (DCS)
These two charts (separated on frequency bands), plot the RxQual
for every BCCH. This is helpful to spot whether quality problems,
overall, are due to a few bad channels or if it is spread all
over.
Quality to BCCH versus BSIC (GSM) and (DCS)
These two charts are again separated by frequency bands. These
charts plot the BSIC value v/s BCCH.
In GSM cells re-use is discriminated by BSIC values. Hence BSIC
becomes an ideal value for identifying interferers. These charts
can be viewed for generic analysis. If you see more than one BSIC
for a BCCH, then this could be that the phone moved through
multiple co-channel carriers. This could happen if the drive test
was long or possibly the BSIC toggled with interfering
carriers.
The second use for these charts is when the drive test is done
for a specific purpose of troubleshooting an interferer. Where the
phone is locked on to a BCH. At that time the phone would start
losing out on the prime carrier and might start reporting instances
of the interferer BSIC. This is easily spotted from this chart.
Quality versus TCH State
This chart gives a spread of RxQual with respect to the state of
traffic channel. Even if the channel was hopping or not. From this
you can see which mode of TCH (Hopping or Non-Hopping) is giving
poor quality.
Performance By Cells Report
This analysis is a highly detailed drilled down analysis where
the entire drive data is filtered for every unique cell which the
phone traversed during the drive.
For every cell there is a statistical analysis for critical
parameters from which you can easily find out the problem cells.
This data helps you in trimming down analysis in post-processing
down to selected cells, rather than the total drive.
The last column, for every parameter in the table, provides
details on what kind of statistical calculation has been made.
The parameter Availability supercedes other statistical
parameters.
If Availability is low then the cell can be ignored or if a
particular cell or cells is/are having accessibility or usage
problem, you can assess this from this parameter.
Note: If Availability is low, certain parameter statistics might
not be applicable since the phone might not have gone through the
states to get these measurement parameters.
At the end of the Performance by Cells table, there is a short
summary table, which lists the overall performance on a cell basis.
The explanation of these parameters is given in an extra column.
These parameters help in highlighting how much distribution of poor
quality and/or coverage there is over cells.
Note: A very interesting application of the above data is that
this data can be taken out in a CSV form and loaded into a Post
Processing Table, hence along with the full drive data, we can see
a layer of cell summary, giving us complete guidance on our data
analysis approach
Performance By Calls Report
This table shows the performance on a per call basis. For every
call it gives call setup related parameters, for example start of
call time, setup time, and so on. If the call is successful you can
see how good or bad the call quality was.
Based on the quality parameters it also generates a CQI (call
quality index). At the end of the table, there is a summary of the
total calls and call wide summary.
Neighbor and Handover SummaryNeighbor Availability
Statistics
This chart shows the analysis of neighbor availability.
It counts the number of neighbors reported above 97 dBm for
every measurement sample, and on this count generates the
histogram.
A high percentage value on the left of the chart means that
coverage is not adequate and less cell signals are seen by the
phone or the network parameters are not optimised.
Neighbor (Top 2 Strongest Received Level)
This histogram is a chart of the first and second strongest
neighbor cells received signal level.
Band Usage
This chart shows the analysis of the frequency band used by the
phone in the serving cell.
Handover Summary Statistics
This table shows a summary of analysis results on handover
performance. It gives total calls, that are then divide the
handover related count into:
Attempts
Completion
Failure
At foot of the table you are given the average number of
inter-cell and intra-cell handovers per call.
Mobility Summary
This table indicates the mobility performance with a summary of
the location update process and a count of the number of total cell
re-selections.
Handover Graph
This is a line chart indicating the change in BCH values over
time> This helps you see the handover methodology used during
the drive test.
Handover to Strongest Neighbor Number
This chart indicates the probability of handovers happening to
the 1st, 2nd and up to 6th strongest neighbors. Ideally the
handovers should happen to the first or second neighbors but if
more values are seen on the right side of the chart, then there is
a possibility of congestion and neighbor non-suitability
problems.
Cell Re-Selection Graph
This is a line chart indicating the cell change process, with
Cell ID on the Y-axis.
Handover Drill DownHandover Cause Chart
The pie chart and table shows results from every handover. It
shows handover related parameters, such as:
RxQual
RxLev
TA before the Handover
From these you can derive the estimated handover cause. The pie
chart then summarises these estimated handover causes.
See alsoGSM Phone Reports - Details
The GSM phone menu option provides the following reports:
Executive Summary
This report provides three main sub reports:
Call Statistics Chart
This is a bar chart showing the results displayed in the Call
Statistics details table. Statistics that highlight potential
problem areas are highlighted in red.
Call Statistics Details
This provides a table values counted from the imported data. The
values shown in this table are also displayed in the Call
Statistics Chart above.
HYPERLINK "javascript:kadovTextPopup(this)" Click here for a
list of values provided
Total Calls
Total Billable Calls
Blocked Calls
Dropped Calls
Total Cell Access
Successful Call Setups
Successful Channel Assignments
Total Disconnects
Total Drops
Handover Attempts
Handovers Successful
Handover Failures
Quality Performance Summary
This table shows you maximum, minimum, and average RF values
from your imported measurement data. You are also provided all the
values that have exceeded your preset threshold values, which are
also shown.
Click here for a list of values provided
Phone State
No Service
Hopping
RxLev Full
RxLev Sub
N1 RxLev
N2 RxLev
RxQual Sub
FER
RLTC
Tx Level
Timing Advance
Overall Performance Summary
This report provides details on how well your network has been
performing in of RF and signal quality. This report has 10 main sub
reports:
Phone State
This is a bar chart showing the phone states found in your
measurement data. The three states are:
Idle (Green)
Dedicated (Dark Blue)
No Service (Red)
DTX State
This is a bar chart showing the phone transmitter state during
testing. The two states shown are:
Off (value "0") (Yellow)
On (value "1") (Green)
Hopping State
This is a bar chart showing the phone hopping states during
testing. The two states shown are:
Hopping (Purple)
No Hopping (Maroon)
RxQual
This is a bar chart showing the ranges of RxQual found during
testing. The states shown are:
0 (Green)
1 (Cyan)
2 (Cyan)
3 (Cyan)
4 (Violet)
5 (Red)
6 (Red)
7 (Red)
FER
This is a bar chart showing the ranges of FER found during
testing. The states shown are:
0% (Green)
0 to 5% (Cyan)
5 to 10% (Cyan)
10 to 20% (Cyan)
20 to 40% (Violet)
40 to 70% (Red)
70 to 90% (Red)
90 to 100% (Red)
RxLev Full and RxLev Sub chart
(Dark Blue)
Timing Advance
0 to 1
1 to 5
5 to 10
10 to 20
20 to 35
35 to 50
50 to 63
All bars are shown in green.
RLTC Current Values
0
1
2
3 to 6
6 to 10
10 to 16
>16
0 is green, all others are red.
DSF Current Value Changes
0
1
2
3 to 6
6 to 10
10 to 16
>16
0 is green, all others are red.
Call Quality
This report provides information about call quality and call
coverage. Selecting this report will provide the following
information:
RxLev and RxQual variations
RxQual versus RxLev
Uplink performance estimation
Distance to coverage
Quality to handovers
Quality to BCCH
BCH versus BSIC
Quality versus TCH State
Performance By Cells
This report provides a table of performance results based on
cell information.
Click here to see the table contents
Latitude
Min RxQual
Max TxLev
Longitude
Max RxQual
Average TxLev
Cell ID
Average RxQual
Min Timing Advance
% Availability
Average FER
Max Timing Advance
BCH
Min RxLev
Average Timing Advance
TCH State
Max RxLev
Min RLTC
Outgoing Calls
Average RxLev
Incoming Calls
Average N1 RxLev
Outgoing Handovers
Average N2 RxLev
Incoming Handovers
Min TxLev
Performance By Calls
This report provides a table of performance results based on
call information.
Click here to see the table contents
Latitude
Longitude
Time
Call ID
Call Duration
CQI - Call Quality Index - Range 0-5, where 0 is poor and 5 is
excellent
CellID of Start
BCH -Start
CellID End
BCH-End
TCH State
ARFCN
MAIO
Block Call
Drop Call Counter
Intra Cell Handovers
Inter Cell Handovers
Time of Service Request
Time of Call Setup
Time of Call Proceeding
Time of Alerting
Time of Disconnect Request
Time of Call Release
Time To Connect Calls
Time to Confirm instruction to connect
Time to Release Call
Min RxQual
Max RxQual
Avg RxQual
Min RLTC
Avg. FER
Min RxLev
Max RxLev
Avg RxLev
Avg N1 RxLev
Avg N2 RxLevel
Min TxLevel
Max TxLevel
Avg TxLevel
Min Timing Advance
Max Timing Advance
Avg Timing Advance
Handover and Neighbor Analysis
Handover Drill Down Analysis