BSSGP Tab Parameters

When you configure a UMTS test case for Gb interface testing by selecting the GPRS protocol stack, the Gb tab is displayed. With it, you can define the location/routing information, BSS link rates and transport protocol attributes for the RAN side of the Gb interface.

During MME Nodal testing, the BSSGP tab displays for Mobility testing when Handoff Protocol is GPRS on the Test Configuration tab.

This topic describes the Gb interface settings. The topics listed under Related Parameters describe the other settings used in the UMTS test case.

Location and Routing Information Location Area Code Range Routing Area Code Cell ID Reset Cell ID	BVC Rate (msgs/s) Mobile Country Code Mobile Network Code
Suspend Options Periodic Suspend Continuous Suspend Number of Suspends	Suspend Retries Timer (ms) T3 Ack Timer (ms)	Resume After Suspend/RAU After Suspend Resume Retries Timer (ms) T4 Ack Timer (ms)
Flow Control BVC Bucket Size BVC Bucket Leak Rate	Default Bucket Size Default Bucket Leak Rate
Radio Status Command
RA Capability BVC Reset
RAN Information Management RIM Multi-Report Timer (ms) Apply RIM Based Application Test Data File to System Information Messages

Related Measurements

BSS GPRS Protocol Settings

Define the Location Area Code and Routing Area Code settings for the BSS nodes.

Location and Routing Information

You can configure the test to assign the same LAC, RAC and Cell ID to every MN or define a range of values that will be evenly distributed among the MNs. These values are used in both the BSSGP and GMM layers. Enter the same value in the Start and End field to use that value for every MN. Enter the lowest value in the Start field and the highest value in the End field to define a range of values. When you define a range of values, the value is incremented for each MN. Example:Example:

Assuming the following settings:

Number of MNs: 5

LAC range: 0— 2

RAC range: 0— 1

The MNs will be assigned LAC/RAC combinations in a round-robin manner:

MN 1: 0/0

MN 2: 1/1

MN 3: 2/0

MN 4: 0/1

MN 5: 1/0

NOTE: Ensure that the LAC range defined on the Mobility Gb tab does not overlap the range on the Gb tab. Handoffs must be performed between different LAC/RAC combinations.

Location Area Code Range

Range: 0 — 65535

Default: 0

Tcl Parameter:

RanapLac_1

RanapLacEnd_1

Routing Area Code Range

Range: 0 — 255

Default: 0

Tcl Parameter:

RanapRac_1

RanapRacEnd_1

Cell ID Range

Range: 0 — 65535

Default: 0

Tcl Parameter:

BssgpCellId_1

BssgpCellIdEnd_1

Reset Cell ID

Select Reset Cell ID to ensure that the BVCI is unique across different NSE.

Tcl Parameter: BssgpResetCellIdEn_1

Values: True/False

Default: True

BVC Rate

BSSGP virtual connections (BVCs) are end-to-end virtual connections between the BSS and the SGSN at BSSGP layer. BVC rate determines the rate at which BVCs are established.

A BVC is identified by a BVCI that has an end-to-end significance across the Gb interface.

Range: 0 - 1000

Default: 0 (0 indicates this value not being used)

Tcl Parameter:

BvcRateConfigured_1

BvcRateConfigured_2

The following parameters define the remaining location and routing information elements for the RANAP layer.

Mobile Network Code

Range: 00 — 999 (2-3 digits; leading zeros are retained)

Default: 00

Tcl Parameter: RanapMnc_1

Mobile Country Code

Range: 000 — 999 (leading zeros are retained)

Default: 000

Tcl Parameter: RanapMcc_1

^ Back to Top

Suspend Options

During UMTS testing, the Suspend Options apply to the Capacity, Session Loading, QoS Update, and Command Mode Test activities only.

Periodic Suspend

Use the Periodic Suspend check box to enable and specify whether to send continuous or a defined number of Suspend requests to the SGSN to suspend its GPRS services.

Tcl Parameter: PeriodicSuspendEn_1

Continuous Suspend

Use the Continuous Suspend check box to specify whether Suspends are sent continuously.

Tcl Parameter: SuspendContinuousEn_1

Number of Suspends

Enter the number of Suspends to indicate how long to delay before sending a Suspend after the attach.

Tcl Parameter: SuspendNum_1

Suspend Retries

Use the Suspend Retries parameter to specify how many times to retry the transmitting a message without getting a response from the SUT.

Tcl Parameter: SuspendRetries_1

Timer

Use the Timer parameter to specify how long to delay before sending a Suspend request. If more than 1 Suspend is being sent, this parameter indicates how long to delay after sending the Resume or Routing Area Update (RAU).

Tcl Parameter: SuspendTimer_1

T3 - Ack Timer

Use the T3 Ack Timer parameter to specify the number of seconds to wait for a command request response from the SUT before retrying. The T3 timer starts when a signaling request message (for which a response has been defined) is sent.

Tcl Parameter: SuspendAckTimer_1

Resume After Suspend

Select the Resume after Suspend or RAU (Routing Area Update) after the Suspend from the dropdown list to specify whether to resume transmitting after Suspend or a RAU.

Tcl Parameter: ResumeType_1

Resume Retries

Use the Resume Retries parameter to specify the number of seconds to delay before sending the Resume/RAU after the Suspend request is sent.

Tcl Parameter: ResumeRetries_1

Resume Timer

Use the Resume Timer to specify the number of seconds to wait for a command request response from the SUT before resuming.

Tcl Parameter: ResumeTimer_1

T4 - Ack Timer

Use the T4 Ack Timer parameter to specify the number of seconds to wait for a command request response from the SUT before retrying. The T4 timer starts when a signaling request message (for which a response has been defined) is sent.

Tcl Parameter: ResumeAckTimer_1

^ Back to Top

BSS Link Rates

When the test begins, the Control node attempts to establish the defined BSS links with the SGSN SUT. The links are maintained through the life of the test and after the last MN has successfully detached, the links are torn down.

BSS Link Activation Rate

The number of RNC links that the test attempts to establish every second. All RNC links must be successfully established before any GMM attaches are attempted.

Range: Variable1

Default: 1

Tcl Parameter:

BSS Link Deactivation Rate

The number of BSS links that the test attempts to tear down every second. All MNs must successfully detach from the SGSN before any BSS links are torn down.

Range: Variable1

Default: 1

Tcl Parameter:

BSS Disconnect Delay

The number of milliseconds after the last MN is detached that the test will wait before beginning to tear down the BSS links.

Range: 0 — 65535

Default: 0

Tcl Parameter:

1 Maximum rates, number of sessions, and number of emulated nodes vary depending on the test application and the test system's licensed capacity.

^ Back to Top

Flow Control

The flow control parameters that are provided by the BSS within the flow control PDUs are the BVC Bucket size and the BVC Bucket Leak Rate. You can also establish the Default Bucket Size and Default Bucket Leak Rate to ensure that the amount of memory used by each flow context within the BSS (for each BVC and each mobile within this BVC). It also helps determine the exact amount of available space within the bucket.

Once the BVC has been established, the BSS must indicate the amount of memory available for the BVC for flow control between the SGSN and the BSS. The BSSGP flow control mechanism is based on a bucket algorithm.

The BVC Bucket Size is the amount of memory available for each flow context within the BSS (for each BVC and each mobile within this BVC).

Every time an LLC PDU is sent in downlink toward the BSS, the flow control mechanism at SGSN side verifies whether the maximum bucket size for the mobile and BVC context will be reached (if this LLC PDU is sent to BSS). If both maximum bucket sizes are not reached, the PDU is sent toward the BSS.

The BVC Bucket Leak Rate helps the SGSN estimate the bucket size at any time. The SGSN gets information about the bucket leak rate at mobile and BVC levels when the bucket on the BSS side empties as LLC PDUs are sent on the radio interface.

Tcl Parameter:

BvcBucketSize_1	BvcBucketLeakrate_1	DefaultBuckSize_1	DefaultBuckLeakrate_1
BvcBucketSize_2	BvcBucketLeakrate_2	DefaultBuckSize_2	DefaultBuckLeakrate_2

^ Back to Top

Radio Status Command

The Radio Status Command supports sending Radio status from BSSGP layer. Your selection indicates the reason for the BSSGP and MS radio interface communication status change.

NOTE: You may select only one status command option at a time. If you do not select any options, no Radio Status is sent.

The Radio Status Command pane is available when UMTS Version is 8 (on the Test/Emulator Configuration tab) in UMTS, SGSN Node, MME Nodal, and MME Node test cases (Gb (Target Gb) | BSSGP ).

Out of Coverage

Indicates that MS goes out of coverage and the Radio contact is lost.

Class: Basic: Boolean

Values: True / False

Tcl Parameter: BssgpRadioOutOfCoverageEn_1

NOTE: Attempts to communicate between an MS and an SGSN via this cell is suspended or abandoned after the Resend Timer expires (the SGSN stops sending LLC-PDUs to the cell for the MS).

Link Quality Bad

Indicates that link quality is too bad to continue the communication.

Class: Basic: Boolean

Values: True / False

Tcl Parameter: BssgpRadioLinkQualBadEn_1

NOTE: Attempts to communicate between an MS and an SGSN via this cell is suspended or abandoned after the Resend Timer expires (the SGSN stops sending LLC-PDUs to the cell for the MS).

Cell Reselection ordered

Indicates that the BSS has ordered the MS to perform a cell reselection.

Class: Basic: Boolean

Values: True / False

Tcl Parameter: BssgpRadioCellReselectOrderEn_1

NOTE: The SGSN waits for a cell update (until the Resend Timer expires) before resuming the transmission of LLC-PDUs to the BSS.

indicates that

Cell Reselection to New Cell

Indicates that the BSS is preparing to order the MS to perform a cell-reselection to a new cell and internal re-routing of packets to the new cell is not possible.

Class: Basic: Boolean

Values: True / False

Tcl Parameter: BssgpRadioCellReselectNewEn_1

NOTE: The SGSN suspends downlink transmission of LLC-PDUs waits (until the Resend Timer expires) for a cell update from the MS in a new Cell. The SGSN resumes downlink transmission in the new Cell.

Cell Reselection Failure

Indicates that the BSS has detected failure of the packet cell change order.

Class: Basic: Boolean

Values: True / False

Tcl Parameter: BssgpRadioCellReselectFailEn_1

NOTE: The SGSN resumes transmission of LLC-PDUs to the BSS (after the Resend Timer expires) in case the downlink transmission has been suspended.

Resend Timer

Indicates the time to wait before resuming transmission (of LLC-PDUs). The Resend Timer is available only when you select one of the Radio Command options.

Option: 1 - 999

Tcl Parameter: BssgpRadioResendTimer_1

^ Back to Top

RA Capability

Select to test Radio Access Capability Procedure on the UMTS and SGSN Node test cases:

SGSN sends RA Capability PDU to the BSS.
BSS sends RA Capability Update to the SGSN.
SGSN sends RA Capability Update Ack to the BSS

NOTES:

SGSN to BSS	Sends the stored (current) Radio Access Capability of MS and the TLLI (Temporary Logical Link Identifier) identifying the MS, to a BSS in aRA-CAPABILITY-UPDATE-ACK PDU .
BSS to SGSN	Sends a RA_CAPABILITY_UPDATE PDU which includes the TLLI of the MS and requests an MS's current Radio Access capability and/or its IMSI.
SGSN to BSS	Responds by sending a RA-CAPABILITY-UPDATE-ACK PDU which includes the TLLI of the MS (includes the IMSI of the MS if known).

If the received MS's Radio Access Capability, if valid, it then replaces any Radio Access Capability previously associated with the MS.

Tcl Parameter: BssgpBvcResetEn_1

Resend Timer

The RA Capability Resend Timer is available only when you select RA Capability. Indicates the time to wait for a response before the SGSN can resend RA-CAPABILITY PDU to BSS.

The BSS Starts the timer after sending a RA_CAPABILITY_UPDATE PDU (in response to the received RA_CAPABILITY PDU from the SGSN) and stops the timer after receiving a RA-CAPABILITY-UPDATE-ACK PDU from the SGSN.

Tcl Parameter: BssgpBvcResetTimer_1

Option: 1 - 999

One Shot

Available only when you select RA Capability. Select to ensure that the RA Capability procedure is tested only once.

Tcl Parameter: BssgpRadioAccessTimerOneShotEn_1

BVC Reset

Select to allow the BVC-RESET procedure to synchronize the initialization of GPRS BVC related contexts at a BSS and SGSN. This enables the BSS and SGSN to begin communication in known states. A BVC-RESET procedure is performed because of recovery procedures related to:

A system failure in the SGSN or BSS that affects GPRS BVC functionality (for example, processor recovery)
An underlying network service system failure or a change in the transmission capability of the underlying network service, where the change is from zero kbps to greater-than-zero kbps
A change in mapping between the BVCI and cell identifier.

NOTE: The BSS may also send BVC-RESET as a means to create the initial mapping between BVCIs and cell identifications.

Tcl Parameter: BssgpBvcResetEn_1

Resend Timer

The BVC Reset Resend Timer is available only when you select BVC Rest. Indicates the time to wait before performing the BVC Reset procedure.

Tcl Parameter: BssgpBvcResetTimer_1

Option: 1 - 999

RAN Information Management

Rim Multi-Report Times (ms)

Use the RIM Multi-Report Timer (ms) checkbox to enter report timer in ms.

Range: 0 to 65535

Default: 10000

Tcl Parameter: BssRimMultiReportTimer

RIM Based Application Test Data File to System Information Messages

Use the RIM Based Application Test Data File to System Information Messages checkbox to enter a Test Data File (TDF wizard is enabled) for system information messages per 3GPP TS 44.060.

See sample test data file: rimPsiMessages10_10.txt

The input test file usage guide:

1) All data is in HEX format

2) Support system information messages specified in 3GP TS 44.060

3) Each line with HEX data is for a system information message:

The first byte is for message type (including 2 bits spare)
total 22 bytes long (for each message)

4) Multi-reports are supported, each report starts and ends with a line of "##############" string

5) Each report is limited to 8 messages (enough for NACC application)

6) Maximum 8 different reports are supported. If a RIM application needs more than 8 reports, the data feed with repeat automatically (reports 1,2, ..., 8, 1,2, ..., 8, ...)

Tcl Parameter: BssRimCfgFileEn

^ Back to Top