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3 Collecting logs using Snapshot feature

3 Collecting logs using Snapshot feature

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Flexi EDGE BTS Feature Descriptions

Figure 6


Collecting logs using Snapshot feature




Flexi EDGE BTS Feature Descriptions


5 Operability


BTS Trace Tool

BTS Trace Tool is built in the BTS Manager application and can be used to collect

detailed logs when investigating a problem seen on a customer BTS site. The tool can

be controlled either via local or remote BTS Manager minimising the need for site visits.

The tool provides the functionality to collect logs remotely from the BTS site over the

Abis link. In addition to a few standard logs, custom logs can be recorded as well with

the help of custom trace set files provided by the NSN customer support team. The

recorded log files can be decoded and analysed by NSN.





Flexi EDGE BTS Feature Descriptions


Antenna VSWR measurement

Flexi EDGE BTS provides antenna line supervision by means of voltage standing wave

ratio (VSWR) monitoring in the Dual Duplexer Module (ERxA). During commissioning,

the user can set the VSWR minor (7607) and major (7606) alarm limits for each antenna

line separately. The minor limit can be set between 1.5...2.9:1 (that is, with a return loss

14.0 - 6.2 dB) and the major limit between 2.7...3.5:1 (6.8 - 5.1 dB). The default limits on

the Flexi EDGE BTS Manager are 2.1:1 (minor) and 3.1:1 (major) which convert to 9 dB

(minor) and 5.8 dB (major) return loss (RL) respectively. At the end of the commissioning

process, the values are stored in the site configuration file (SCF) in the System Module's

(ESMA) non-volatile memory. During normal BTS operation, the Dual TRX Module

(EXxx) sends a polling request to the Dual Duplexer Module every few seconds. The

Dual Duplexer Module responds with a message containing the return loss values for

both antenna paths (A and B). The VSWR limit for output TX power at DDU (ERxA)

module is 0…5 and at RTC (ECxA) module is 0…2. The Dual Duplexer Module can

report the return loss reliably if the TX power in its TxA or TxB input exceeds approximately +32 dBm. The BTS software converts the reported return loss values to VSWR

values, and compares them with the minor and major limits found in the site configuration file. If the reported VSWR exceeds the minor limit, alarm 7607 'TRX operation

degraded' is activated. If the reported VSWR exceeds the major limit, alarm 7606 'TRX

faulty' is activated, and the affected TRX objects are blocked.

Typical causes for a bad VSWR are broken cables, broken connectors and the ingress

of water in the antenna cable path.


BCCH antenna VSWR measurement

If the antenna line on Dual Duplexer (ERxx) module carries BCCH, twelve consecutive

return loss measurements are analysed. If the operation is suddenly degraded and a

sporadic bad reading is received, the analysis is reset and a new set of measurements

is collected. If all consecutive measurements are bad, a minor or major alarm is activated depending on how bad the result is. Likewise, all consecutive measurements have

to be OK before the alarm is cancelled. Only minor (7607) can be cancelled automatically while major (7606) alarm is blocking.

The BCCH antenna VSWR measurement feature works with both Dual Duplexer

(ERxA) and RTC (ECxA) modules. The feature does not work in an antenna hopping



TCH antenna VSWR measurement

For TCH only antenna lines (that is, TCH only TRX(s) are connected to this antenna),

antenna boosting may be needed to generate temporary Tx signal for the Dual Duplexer

(ERxx) module so that it would be able to measure the VSWR condition. If antenna

boosting is needed due to lack of traffic, the first TRX object from the Dual TRX (EXxx)

module connected to Dual Duplexer (ERxA) module transmits a continuous Tx signal on

all traffic, idle and packet-switched time slots for two seconds. The TRX object used for

boosting must be unlocked and in supervisory state. Antenna boosting is only possible

when the BCCH power level is 0…2 (that is, with PMAX values 0, 2 or 4).

If the Dual Duplexer (ERxx) module has reported insufficient Tx power for TCH only

antenna for one hour, antenna boosting is started. If insufficient power level is still

reported after the boosting period, blocking alarm 7606 'ERxx DDU module has





Flexi EDGE BTS Feature Descriptions

detected no Tx power at TxA/B input' is raised for all TRX objects connected to this

antenna line.

If the Dual Duplexer (ERxx) module has reported bad VSWR for TCH only antenna line

for one hour, antenna boosting is started as well. If bad VSWR is still reported after the

boosting period, a minor or major VSWR alarm is activated depending on how bad the

result is (such as with BCCH antenna VSWR measurement).


RG301834 Enhancement on monitoring VSWR and RSSI

The feature 'RG301834 Enhancement on monitoring VSWR and RSSI' enhances the

Voltage Standing Wave Ratio (VSWR) and Received Signal Strength Indication (RSSI)

reporting and VSWR threshold management. RSSI data is currently obtained from BTS

Manager/Element Manager, but that data can be obtained only for one BTS at a time.

The optimization service needs to monitor the receiver difference for a large amount of

BTS, and the analysis needs longterm data storage for statistical data. The Element

Manager does not fulfill these requirements. VSWR value is used to detect antenna and

feeder cable problems. VSWR major and minor values can be set by BSC, NetAct or

BTS Element Manager irrespective of the feature license state. To check VSWR values,

user needs to check values for each BTS one by one. The VSWR measured average

value is not available for all the BTSs to enable region level analysis. This feature

obtains VSWR measured average value of each RF path for all the BTSs. In this way,

the user can monitor this value on a region level and does not need to check VSWR on

site for each BTS one by one.

VSWR data can only trigger a VSWR abnormal alarm when the VSWR value is above

the VSWR threshold. There are three limitations in VSWR and RSSI reporting currently:

No VSWR true value display

No VSWR detect module install flag

The VSWR Alarm Threshold is difficult to manage

This feature enables the collection of VSWR and RSSI data from BTS sites and sending

them to NetAct database to enable network level post processing. The data collection is

optional and controlled with the license. This feature also supports the management of

VSWR threshold parameters on network level. For Baseband and Antenna hopping

VSWR is not reported to BSC.

This feature is license key controlled. The type of license is ON/OFF.

Benefits for VSWR enhancement

Enables users to find out the radio problem in a large region instead of using the

BTSmanager to check VSWR threshold on BTS site one by one.

Enables users to change VSWR parameter on working state with MML from BSC

side, which helps to reduce service affecting risk.

Trends of VSWR values can be compared with historic data present using counters.

Benefits for RSSI enhancement

Enables users to find out the RF problem in multiple BTSs without using the BTSmanager, which is currently mandatory.

Provides enhanced efficiency to improve network quality.







Flexi EDGE BTS Feature Descriptions



NetAct OSS5.4 CD2




Flexi EDGE BTS Feature Descriptions


BSC download of Abis mapping

Abis mapping automates the process of providing Abis allocations on the BTS. Instead

of using the information from the Site Configuration File (SCF), the BTS configures the

allocation of the Abis using the information received from the BSC. This configuration is

performed by the BTS, by using mapping algorithms to convert BSC data into BTS Abis

allocations. The mapping between the BSC data and the interfaces at the BTS relies on

reference signals that are collectively known as the Abis Termination information of the

BTS. The Abis mapping information is provided to the BTS. The Abis Termination information is provided to the BTS during commissioning via SCF from the BTS Manager.

One reference signal per interface is supported at the BTS.


A restriction with this feature is that it might be unable to take into account the possible

cross-connections in the Abis line. The BTS believes the Abis timeslot allocations as

defined on BSC but they may not be the same anymore on the BTS end due to crossconnections (if TS offset is also used).

An Abis mapping Information Element (IE) consists of Abis channels (TRXSIG and

TCH) in BTS_CONF_DATA grouped into a bundle. The BTS_CONF_DATA can carry

several instances of Abis mapping IE(s), one for each bundle or interface. The interface

timeslots in the Abis mapping IE(s) from the BSC are the timeslots at the BSC interface.

OMUSIG configuration is still taken from the Abis Termination information already

stored at the BTS, and not from the Abis mapping IE. The timeslot information provided

in the Abis mapping IE is converted into timeslot information for the BTS via the Abis

mapping algorithm. EDAP information is provided using the Dynamic Pool Info IE(s) in

the BTS_CONF_DATA. The interface timeslots in the Dynamic Pool Info IE(s) are the

timeslots at the BSC interface.

The BTS Manager has been enhanced with the Abis mapping download function:


A BSC Abis Mapping Status view menu item has been added in the Transmission

menu of the BTS Manager.

• The BSC Abis mapping facilitates the user to view the differences and conflicts

in the BSC and BTS allocations for a selected interface or a BSC bundle. The

user can select an interface from the list of interfaces displayed in the

Transmission equipment view or select a BSC bundle from an available list of

bundles. As per user selection, the details of the BTS interface, reference signal

and the calculated offset value are displayed.

• This is only available in online mode.

Two check boxes have been added for the BSC Abis mapping download function in

the Abis Termination screen of the Commissioning Wizard:

• Enable Abis Signal Mapping allows the user to enable/disable the Abis signal


• Allow Abis Allocations from BTS Manager allows the user to enable/disable

the Abis allocations from the BTS Manager. If this check box is selected and the

user enters the Abis allocations from the BTS Manager, they might later be overwritten by the allocation data from the BSC.

• These options are available in both online and offline mode.




Flexi EDGE BTS Feature Descriptions


BSS21362 Fast BSS Restart

The “BSS21362 Fast BSS Restart” feature increases the network availability by

reducing the radio network (RNW) downtime in a controlled BSC restart. The reduced

downtime is achieved by restarting the BSC without an RNW restart. The feature is basic

software and its usage is not controlled by a license or parameter. Fast BSS Restart is

not allowed if RNW Plan or RNW Fallback activation is ongoing.

Usually, a BSS system restart is performed to ensure that all the necessary parameters

and information are updated inside BSC and BTS after a BSC software installation, or

during maintenance. During a BSS system restart, the cells go into a barred state for a

while causing downtime in the radio network. The BSC’s computer units become active

and start running depending on the BSC configuration. After that, the RNW takes 1- 82.5

minutes to get active, depending on the BTS site type, BTS software, size of radio

network configuration, and BTS configuration in the BSS.

With the “BSS21362 Fast BSS Restart” feature, after a BSC restart is triggered and

when all its BTSs support the feature, the RNW activation phase takes only 0.5 - 4.5

minutes after all the BSC computer units are raised back to working state. The time

taken depends on the size of RNW configuration in the BSC.

This feature provides the following benefits:

Increased network availability for service usage

All BTSs under BSC support the feature




Flexi EDGE BTS EX4.0 or Flexi Multiradio BTS EX4.1

NetAct OSS5.2 CD set 3




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