5 Elements for layer-to-layer communication

08.183GPPBase Station System (BSS) - Serving GPRS Support Node (SGSN)BSS GPRS ProtocolGeneral Packet Radio Service (GPRS)Release 1999TS

5.1 Definition of service model

In the present document, the communication between adjacent layers and the services provided by the layers are distributed by use of abstract service primitives. Only externally observable behaviour resulting from the description is normatively prescribed by the present document.

The service primitive model used in the present document is based on the concepts developed in CCITT Recommendation X.200 [19].

The service model for a BSS and an SGSN is asymmetric. The service models for a BSS and an SGSN are shown below.

Figure 5.1: BSSGP service model

Primitives consist of commands and their respective responses associated with the services requested of another layer. The general syntax of a primitive is:

– XX – Generic name – Type (Parameters);

where XX designates the layer providing or using the service.

In the present document, XX is:

– "BSSGP" for functions controlling the transfer of LLC frames passed between an SGSN and an MS across the Gb interface;

– "RL" (relay) for functions controlling the transfer of LLC frames between the RLC/MAC function and BSSGP;

– "GMM" (GPRS mobility management) for functions associated with mobility management between an SGSN and a BSS; and

– "NM" (network management) for functions associated with Gb-interface and BSS-SGSN node management.

– "PFM" (packet flow management) for functions associated with the management of BSS Packet Flow Contexts (PFCs).

5.2 Service primitives provided by the BSSGP at a BSS

Table 5.2: Service primitives provided by BSSGP at a BSS

Generic name

Type

Parameters

REQuest

INDication

RESponse

CoNFirm

RL ó BSSGP

RL-DL-UNITDATA

X

BVCI,

NSEI,

Refer to DL-UNITDATA PDU

RL-UL-UNITDATA

X

BVCI,

NSEI,

LSP,

Refer to UL- UNITDATA PDU

RL-PTM-UNITDATA

X

BVCI,

NSEI,

Refer to PTM-UNITDATA PDU

GMM ó BSSGP

GMM-PAGING

X

BVCI,

NSEI,

Refer to PAGING PS PDU

Refer to PDU PAGING CS PDU

GMM-RA-CAPABILITY

X

BVCI,
NSEI,

Refer to RA-CAPABILITY PDU

GMM-RA-CAPABILITY-UPDATE

X

X

BVCI,

NSEI,

Refer to RA-CAPABILITY-UPDATE PDU,

Refer to RA-CAPABILITY-UPDATE-ACK PDU

GMM-RADIO-STATUS

X

BVCI,

NSEI,

Refer to RADIO-STATUS PDU

GMM-SUSPEND

X

X

BVCI,

NSEI,

Refer to SUSPEND PDU

Refer to SUSPEND-(N)ACK PDU

GMM-RESUME

X

X

BVCI,

NSEI,

Refer to RESUME PDU

Refer to RESUME-(N)ACK PDU

NM ó BSSGP

NM-FLUSH-LL

X

X

BVCI,

NSEI,

Refer to FLUSH-LL PDU

Refer to FLUSH-LL-ACK PDU

NM-LLC-DISCARDED

X

BVCI,

NSEI,

Refer to LLC-DISCARDED PDU

NM-FLOW-CONTROL-BVC

X

X

BVCI,

NSEI,

Refer to FLOW-CONTROL-BVC PDU

Refer to FLOW-CONTROL-BVC ACK PDU

NM-FLOW-CONTROL-MS

X

X

BVCI,

NSEI,

Refer to FLOW-CONTROL-MS PDU Refer to FLOW-CONTROL-MS ACK PDU

NM-STATUS

X

X

BVCI,

NSEI,

Refer to STATUS PDU

NM-BVC-BLOCK

X

X

BVCI,

NSEI,

Refer to BVC-BLOCK PDU

Refer to BVC-BLOCK-ACK PDU

NM-BVC-UNBLOCK

X

X

BVCI,

NSEI,

Refer to BVC-UNBLOCK PDU

Refer to BVC-UNBLOCK-ACK PDU

NM-BVC-RESET

X

X

X

X

BVCI,

NSEI,

Refer to BVC-RESET PDU

Refer to BVC-RESET-ACK PDU

NM-TRACE

X

BVCI,

NSEI,

Refer to SGSN-INVOKE-TRACE PDU

PFM ó BSSGP

PFM-DOWNLOAD-BSS-PFC

X

BVCI, NSEI

Refer to DOWNLOAD-BSS-PFC PDU

PFM-CREATE-BSS-PFC

X

X

BVCI, NSEI

Refer to CREATE-BSS-PFC PDU

Refer to CREATE-BSS-PFC-ACK PDU

Refer to CREATE-BSS-PFC-NACK PDU

PFM-MODIFY-BSS-PFC

X

X

BVCI, NSEI

Refer to MODIFY-BSS-PFC PDU

Refer to MODIFY-BSS-PFC-ACK PDU

PFM-DELETE-BSS-PFC

X

X

BVCI, NSEI

Refer to DELETE-BSS-PFC PDU

Refer to DELETE-BSS-PFC-ACK PDU

5.2.1 RL-DL-UNITDATA.ind

Receipt of a DL-UNITDATA PDU from an SGSN by a BSS containing an LLC-PDU and MS control information necessary for the transmission of the LLC-PDU across the radio interface.

5.2.2 RL-UL-UNITDATA.req

Request to send a UL-UNITDATA PDU to an SGSN from a BSS containing an LLC-PDU and radio interface derived information.

5.2.3 RL-PTM-UNITDATA.ind

This shall be developed in GPRS phase 2.

5.2.4 GMM-PAGING.ind

Receipt of a PAGING PS or PAGING CS PDU from an SGSN by a BSS containing instructions to page an MS within a given group of cells.

5.2.5 GMM-RA-CAPABILITY.ind

Receipt of a RA-CAPABILITY PDU from an SGSN by a BSS providing the new Radio Access capability of an MS.

5.2.6 GMM-RA-CAPABILITY-UPDATE.req

Request to send a RA-CAPABILITY-UPDATE PDU to an SGSN from a BSS in order to receive the current Radio Access capabilities of an MS.

5.2.7 GMM-RA-CAPABILITY-UPDATE.cnf

Receipt of a RA-CAPABILITY-UPDATE-ACK PDU from a SGSN by a BSS containing the current Radio Access capabilities of an MS.

5.2.8 GMM-RADIO-STATUS.req

Request to send a RADIO-STATUS PDU to an SGSN from a BSS to report that an exception condition occurred in the operation of the radio interface for an MS.

5.2.9 GMM-SUSPEND.req

Request to send a SUSPEND PDU to an SGSN from a BSS to mark an MS’s GPRS service as suspended.

5.2.10 GMM-SUSPEND.cnf

Receipt of a SUSPEND-ACK PDU from an SGSN by a BSS confirming that an SGSN has marked an MS’s GPRS service as suspended.

5.2.11 GMM-RESUME.req

Request to send a RESUME PDU to an SGSN from a BSS to mark an MS’s GPRS service as resumed.

5.2.12 GMM-RESUME.cnf

Receipt of a RESUME-ACK PDU from an SGSN by a BSS confirming that an SGSN has marked an MS’s GPRS service as resumed.

5.2.13 NM-FLUSH-LL.ind

On receipt of a FLUSH-LL PDU by a BSS from an SGSN, the BSS will either delete queued LLC-PDUs for a TLLI or move the queued LLC-PDUs from an old to a new BVC. If there is a BSS context for the Mobile Station identified by the TLLI and the BSS is able to move the queued LLC-PDUs, the BSS has to move the BSS context from the old to the new BVC, even if it is not able to offer the same QoS characteristics in the new BVC.

5.2.14 NM-FLUSH-LL.res

Sending of a FLUSH-LL-ACK PDU to the SGSN from a BSS to report if queued LLC-PDU(s) for an MS were deleted or transferred from the old to the new cell within the NSE. The FLUSH-LL-ACK PDU may also report whether the QoS characteristics of the BSS context associated to the MS could be kept in the new cell.

5.2.15 NM-LLC-DISCARDED.req

Request to send a LLC-DISCARDED PDU to an SGSN from a BSS indicating that LLC frames pertaining to an MS have been locally discarded.

5.2.16 NM-FLOW-CONTROL-BVC.req

Request to send a FLOW-CONTROL PDU to an SGSN from a BSS indicating the ability of a BVC to accept a certain flow of data.

5.2.17 NM-FLOW-CONTROL-BVC.cnf

Confirmation that a FLOW-CONTROL PDU has been received by an SGSN for a given BVC.

5.2.18 NM-FLOW-CONTROL-MS.req

Request to send a FLOW-CONTROL PDU to an SGSN from a BSS indicating the ability to accept a certain flow of data for a given MS.

5.2.19 NM-FLOW-CONTROL-MS.cnf

Confirmation that a FLOW-CONTROL PDU has been received by an SGSN for a given MS.

5.2.20 NM-STATUS.req

Request to send a STATUS PDU to an SGSN from a BSS to report that an exception condition occurred within the BSS.

5.2.21 NM-STATUS.ind

Receipt of a STATUS PDU from an SGSN by a BSS indicating that an exception condition occurred within an SGSN.

5.2.22 NM-BVC-BLOCK.req

Request to send a BVC-BLOCK PDU to an SGSN from a BSS to mark a BVC as blocked.

5.2.23 NM-BVC-BLOCK.cnf

Receipt of a BVC-BLOCK-ACK PDU from an SGSN by a BSS confirming that an SGSN has marked a BVC as blocked.

5.2.24 NM-BVC-UNBLOCK.req

Request to send a BVC-UNBLOCK PDU to an SGSN from a BSS to mark a BVC as unblocked.

5.2.25 NM-BVC-UNBLOCK.cnf

Receipt of a BVC-UNBLOCK-ACK PDU from an SGSN by a BSS confirming that an SGSN has marked a BVC as unblocked.

5.2.26 NM-BVC-RESET.req

Request to send a BVC-RESET PDU to an SGSN from a BSS to reset an SGSN’s GPRS BVC contexts.

5.2.27 NM-BVC-RESET.res

Sending of a BVC-RESET-ACK PDU to the SGSN from an BSS indicating that a GPRS BVC context has been reset in the BSS.

5.2.28 NM-BVC-RESET.ind

Receipt of a BVC-RESET PDU at a BSS from an SGSN indicating that GPRS BVC contexts have been reset at the SGSN.

5.2.29 NM-BVC-RESET.cnf

Receipt of a BVC-RESET-ACK PDU at a BSS confirming that GPRS BVC context has been reset at the SGSN.

5.2.30 NM-TRACE.ind

Receipt of a SGSN-INVOKE-TRACE PDU at a BSS from an SGSN indicating the need to produce a trace record on an MS.

5.2.31 PFM-DOWNLOAD-BSS-PFC.req

Upon a request to transfer an uplink or downlink LLC PDU for which it currently does not have a BSS Packet Flow Context, the BSS may send a DOWNLOAD-BSS-PFC PDU to an SGSN.

5.2.32 PFM-CREATE-BSS-PFC.ind

Receipt of a CREATE-BSS-PFC PDU at a BSS from an SGSN indicating that the BSS should create or modify a BSS Packet Flow Context using the Aggregate BSS QoS Profile.

5.2.33 PFM-CREATE-BSS-PFC.res

Sending of a CREATE-BSS-PFC-ACK PDU to the SGSN from a BSS to respond with an Aggregate BSS QoS Profile or a CREATE-BSS-PFC-NACK in case the BSS was unable to create the PFC.

5.2.34 PFM-MODIFY-BSS-PFC.req

Request to send a MODIFY-BSS-PFC PDU to an SGSN from a BSS to modify an Aggregate BSS QoS Profile.

5.2.35 (void)

5.2.36 (void)

5.2.37 PFM-MODIFY-BSS-PFC.cnf

Reception of a MODIFY-BSS-PFC-ACK PDU at a BSS from an SGSN confirming the modification of an Aggregate BSS QoS Profile.

5.2.38 PFM-DELETE-BSS-PFC.ind

Receipt of a DELETE-BSS-PFC PDU at a BSS from an SGSN to delete an Aggregate BSS QoS Profile.

5.2.39 PFM-DELETE-BSS-PFC.res

Sending of a DELETE-BSS-PFC-ACK PDU to an SGSN from a BSS to respond to a deletion.

5.3 Service primitives provided by the BSSGP at an SGSN

Table 5.3: Service primitives provided by BSSGP at an SGSN

Generic name

Type

Parameters

REQuest

INDication

RESponse

CoNFirm

LL ó BSSGP

BSSGP-DL-UNITDATA

X

BVCI,

NSEI,

LSP,

Refer to DL-UNITDATA PDU

BSSGP-UL-UNITDATA

X

BVCI,

NSEI,

Refer to UL-UNITDATA PDU

BSSGP-PTM-UNITDATA

X

BVCI,

NSEI,

Refer to PTM-UNITDATA PDU

GMM ó BSSGP

GMM-PAGING

X

BVCI,

NSEI,

Refer to PAGING PS PDU

Refer to PAGING CS PDU

GMM-RA-CAPABILITY

X

BVCI,

NSEI,

Refer to RA-CAPABILITY PDU

GMM-RA-CAPABILITY-UPDATE

X

X

BVCI,

NSEI,

Refer to RA-CAPABILITY-UPDATE PDU,

Refer to RA-CAPABILITY-UPDATE-ACK PDU

GMM-RADIO-STATUS

X

BVCI,

NSEI,

Refer to RADIO-STATUS PDU

GMM-SUSPEND

X

BVCI,

NSEI,

Refer to SUSPEND PDU

Refer to SUSPEND-(N)ACK PDU

GMM-RESUME

X

BVCI,

NSEI,

Refer to RESUME PDU

Refer to RESUME-(N)ACK PDU

NM ó BSSGP

NM-FLUSH-LL

X

X

BVCI,

NSEI,

Refer to FLUSH-LL PDU

Refer to FLUSH-LL-ACK PDU

NM-LLC-DISCARDED

X

BVCI,

NSEI,

Refer to LLC-DISCARDED PDU

NM-FLOW-CONTROL-BVC

X

BVCI,

NSEI,

Refer to FLOW-CONTROL-BVC PDU Refer to FLOW-CONTROL-BVC ACK PDU

NM-FLOW-CONTROL-MS

X

BVCI,

NSEI,

Refer to FLOW-CONTROL-MS PDU Refer to FLOW-CONTROL-MS ACK PDU

NM-STATUS

X

X

BVCI,

NSEI,

Refer to STATUS PDU

NM-BVC-BLOCK

X

BVCI,

NSEI,

Refer to BVC-BLOCK PDU

Refer to BVC-BLOCK-ACK PDU

NM-BVC-UNBLOCK

X

BVCI,

NSEI,

Refer to BVC-UNBLOCK PDU

Refer to BVC-UNBLOCK-ACK PDU

NM-BVC-RESET

X

X

X

X

BVCI,

NSEI,

Refer to BVC-RESET PDU

Refer to BVC-RESET-ACK PDU

NM-TRACE

X

BVCI,

NSEI,

Refer to SGSN-INVOKE-TRACE PDU

PFM ó BSSGP

PFM-DOWNLOAD-BSS-PFC

X

BVCI, NSEI

Refer to DOWNLOAD-BSS-PFC PDU

PFM-CREATE-BSS-PFC

X

X

BVCI, NSEI

Refer to CREATE-BSS-PFC PDU

Refer to CREATE-BSS-PFC-ACK PDU

Refer to CREATE-BSS-PFC-NACK PDU

PFM-MODIFY-BSS-PFC

X

X

BVCI, NSEI

Refer to MODIFY-BSS-PFC PDU

Refer to MODIFY-BSS-PFC-ACK PDU

PFM-DELETE-BSS-PFC

X

X

BVCI, NSEI

Refer to DELETE-BSS-PFC PDU

Refer to DELETE-BSS-PFC-ACK PDU

NOTE: The parameters in the BSSGP-DL-UNITDATA and BSSGP-UL-UNITDATA primitives that are not included in the corresponding primitives in 3GPP TS 04.64 are provided or extracted by some intermediate function out of the scope of the present document.

5.3.1 BSSGP-DL-UNITDATA.req

Request to send a DL-UNITDATA PDU to a BSS from an SGSN containing an LLC-PDU and control information necessary for the transmission of the LLC-PDU across the radio interface.

5.3.2 BSSGP-UL-UNITDATA.ind

Receipt of a UL-UNITDATA PDU from a BSS by an SGSN containing an LLC-PDU and radio interface derived information.

5.3.3 BSSGP-PTM-UNITDATA.req

This shall be developed in GPRS phase 2.

5.3.4 GMM-PAGING.req

Request to send a PAGING PS or PAGING CS PDU from an SGSN to a BSS containing instructions to page an MS within a given group of cells.

5.3.5 GMM-RA-CAPABILITY.req

Request to send a RA-CAPABILITY PDU to the BSS from an SGSN containing the Radio Access capability of an MS.

5.3.6 GMM-RA-CAPABILITY-UPDATE.ind

Receipt of a RA-CAPABILITY-UPDATE PDU from a BSS by an SGSN, requesting that the SGSN sends the Radio Access capability of an MS to the BSS.

5.3.7 GMM-RA-CAPABILITY-UPDATE.res

Sending of a RA-CAPABILITY-UPDATE-ACK PDU to the BSS from an SGSN containing the current Radio Access capability of an MS.

5.3.8 GMM-RADIO-STATUS.ind

Receipt of a RADIO-STATUS PDU from a BSS by an SGSN to report that an exception condition occurred in the operation of the radio interface for an MS.

5.3.9 GMM-SUSPEND.ind

Receipt of a SUSPEND PDU from a BSS by an SGSN indicating that an MS wishes to suspended its GPRS service.

5.3.10 GMM-RESUME.ind

Receipt of a RESUME PDU from a BSS by an SGSN indicating that an MS wishes to resume its GPRS service.

5.3.11 NM-FLUSH-LL.req

Request to send a FLUSH-LL PDU from an SGSN to a BSS, instructing the BSS to either delete queued LLC-PDUs for a TLLI or move the queued LLC-PDUs from an old to a new BVC.

5.3.12 NM-FLUSH-LL.cnf

Receipt of a FLUSH-LL-ACK PDU at an SGSN informing if the queued LLC-PDU(s) for an MS were deleted or transferred from the old to the new cell within the NSE. The FLUSH-LL-ACK PDU may also report whether the QoS characteristics of the BSS context associated to the MS could be kept in the new cell.

5.3.13 NM-LLC-DISCARDED.ind

Receipt of a LLC-DISCARDED PDU from a BSS by an SGSN indicating that LLC frames pertaining to an MS have been locally discarded.

5.3.14 NM-FLOW-CONTROL-BVC.ind

Receipt of a FLOW-CONTROL PDU from a BSS by an SGSN indicating the ability of a BVC to accept a certain flow of data.

5.3.15 NM-FLOW-CONTROL-MS.ind

Receipt of a FLOW-CONTROL PDU from a BSS by an SGSN indicating the ability to accept a certain flow of data for a given MS.

5.3.16 NM-STATUS.req

Request to send a STATUS PDU to a BSS from an SGSN to report that an exception condition occurred within an SGSN.

5.3.17 NM-STATUS.ind

Receipt of a STATUS PDU from a BSS by an SGSN indicating an exception condition occurred within the BSS.

5.3.18 NM-BVC-BLOCK.ind

Receipt of a BVC-BLOCK PDU from a BSS by an SGSN indicating that a BVC shall be marked as blocked.

5.3.19 NM-BVC-UNBLOCK.ind

Receipt of a BVC-UNBLOCK PDU from a BSS by an SGSN indicating that a BVC shall be marked as unblocked.

5.3.20 NM-BVC-RESET.req

Request to send a BVC-RESET PDU to a BSS from an SGSN to reset a BSS’s GPRS BVC contexts.

5.3.21 NM-BVC-RESET.res

Sending of a BVC-RESET-ACK PDU to the BSS from a SGSN indicating that a GPRS BVC context has been reset in the SGSN.

5.3.22 NM-BVC-RESET.ind

Receipt of a BVC-RESET PDU at an SGSN from a BSS indicating that GPRS BVC contexts have been reset at the BSS.

5.3.23 NM-BVC-RESET.cnf

Receipt of a BVC-RESET-ACK PDU at an SGSN confirming that GPRS BVC contexts have been reset at the BSS.

5.3.24 NM-TRACE.req

Request to send an SGSN-INVOKE-TRACE PDU to a BSS from an SGSN to begin producing a trace record on an MS.

5.3.25 PFM-DOWNLOAD-BSS-PFC.ind

Receipt of a DOWNLOAD-BSS-PFC PDU at an SGSN from a BSS.

5.3.26 PFM-CREATE-BSS-PFC.req

Sending of a CREATE-BSS-PFC PDU to a BSS from an SGSN requesting that the BSS should create or modify a BSS Packet Flow Context using the Aggregate BSS QoS Profile.

5.3.27 PFM-CREATE-BSS-PFC.cnf

Receipt of a CREATE-BSS-PFC-ACK PDU at an SGSN from a BSS confirming the creation or modification of a BSS Packet Flow Context using the Aggregate BSS QoS Profile or a CREATE-BSS-PFC-NACK in to indicate the BSS was unable to create the PFC.

5.3.28 PFM-MODIFY-BSS-PFC.ind

Receipt of a MODIFY-BSS-PFC PDU at an SGSN from a BSS to modify an Aggregate BSS QoS Profile.

5.3.29 PFM-MODIFY-BSS-PFC.res

Sending of a MODIFY-BSS-PFC-ACK PDU to a BSS from an SGSN to respond with an Aggregate BSS QoS Profile.

5.3.30 PFM-DELETE-BSS-PFC.req

Sending of a DELETE-BSS-PFC PDU to a BSS from an SGSN to delete an Aggregate BSS QoS Profile.

5.3.31 PFM-DELETE-BSS-PFC.cnf

Receipt of a DELETE-BSS-PFC-ACK PDU at an SGSN from a BSS to confirm the deletion of an Aggregate BSS QoS Profile.

5.4 Primitive parameters

5.4.1 BSSGP Virtual Connection Identifier (BVCI)

BSSGP Virtual Connections (BVCs) provide communication paths between BSSGP entities. Each BVC is used in the transport of BSSGP PDUs between peer point-to-point (PTP) functional entities, peer point-to-multipoint (PTM) functional entities and peer signalling functional entities. Table 5.4 lists the mapping of the BSSGP PDU to the associated functional entity and the BVCI. The BVCI is used to enable the lower network service layer to efficiently route the BSSGP PDU to the peer entity. This parameter is not part of the BSSGP PDU across the Gb interface, but is used by the network service entity across the Gb.

Any BSSGP PDU received by the BSS or the SGSN containing a PDU type that does not fit, according to the mapping defined in table 5.4, with the functional entity identified by the BVCI provided by the network service entity, is discarded and a STATUS PDU with a cause value set to "Protocol error – unspecified" is sent.

A PTP functional entity is responsible for PTP user data transmission. There is one PTP functional entity per cell. Within 3GPP TS 08.18, a cell is identified by a BVCI unless it is explicitly stated otherwise.

A PTM functional entity is responsible for PTM user data transmission. There is one or more PTM functional entities per BSS.

A signalling functional entity is responsible for other functions e.g. paging. There is only one signalling entity per Network Service Entity (NSE).There is one or more NSEs per BSS.

Each BVC is identified by means of a BSSGP Virtual Connection Identifier (BVCI) which has end-to-end significance across the Gb interface. Each BVCI is unique between two peer Network Service Entities.

In the BSS, it shall be possible to configure BVCIs statically by administrative means, or dynamically. In case of dynamic configuration, the BSSGP shall accept any BVCI passed by the underlying Network Service entity.

At the SGSN side, BVCIs associated with PTP functional entities shall be dynamically configured. The BVCIs associated with signalling functional entities and PTM functional entities are statically configured.

The BVCI value 0000 hex shall be used for the signalling functional entities.

The BVCI value 0001 hex shall be used for the PTM functional entities.

All other values may be used freely by the BSS and shall be accepted by the SGSN.

Table 5.4: BSSGP PDU, BVCI and functional entity mapping

BSSGP PDU

Mapping of BVCI to functional entity

DL-UNITDATA

PTP

UL-UNITDATA

PTP

RA-CAPABILITY

PTP

PTM-UNITDATA

PTM

PAGING-PS

PTP or SIGNALLING (note 1)

PAGING-CS

PTP or SIGNALLING (note 2)

RA-CAPABILITY-UPDATE / RA-CAPABILITY-UPDATE-ACK

PTP

RADIO-STATUS

PTP

SUSPEND / SUSPEND-ACK / SUSPEND-NACK

SIGNALLING

RESUME / RESUME-ACK / RESUME-NACK

SIGNALLING

FLUSH-LL / FLUSH-LL-ACK

SIGNALLING

LLC DISCARDED

SIGNALLING

FLOW-CONTROL-BVC / FLOW-CONTROL-BVC-ACK

PTP

FLOW-CONTROL-MS / FLOW-CONTROL-MS-ACK

PTP

STATUS

PTP or PTM or SIGNALLING (note 3)

BVC-BLOCK / BVC-BLOCK-ACK

SIGNALLING

BVC-UNBLOCK / BVC-UNBLOCK-ACK

SIGNALLING

BVC-RESET / BVC-RESET-ACK

SIGNALLING

SGSN-INVOKE-TRACE

SIGNALLING

DOWNLOAD-BSS-PFC

PTP

CREATE-BSS-PFC / CREATE-BSS-PFC-ACK / CREATE-BSS-PFC-NACK

PTP

MODIFY-BSS-PFC / MODIFY-BSS-PFC-ACK

PTP

DELETE-BSS-PFC / DELETE-BSS-PFC-ACK

PTP

NOTE 1: The network may initiate paging of an MS in READY mobility management state at an indication of a lower layer failure (see 3GPP TS 04.08 clause 4.7.9.1) . In this case, the BVCI=PTP may be used.

NOTE 2: If the network initiates circuit-switched paging of a MS in READY mobility management state (e.g. a MS in class A or B mode of operation and in packet transfer mode), then the BVCI=PTP. If the MS is in STANDBY state, then the BVCI=SIGNALLING.

NOTE 3: The setting of the BVCI is dependent upon the context within which the STATUS PDU was generated.

5.4.2 Link Selector Parameter (LSP)

The link selector parameter is defined in 3GPP TS 08.16 [16]. At one side of the Gb interface, all BSSGP UNITDATA PDUs related to an MS shall be passed with the same LSP, e.g. the LSP is set to the MS’s TLLI, to the underlying network service. The LSPs used at the BSS and SGSN for the same MS may be set to different values.

5.4.3 [functional-name] PDU

The parameters that make up a [functional-name] PDU are defined in PDU Functional Definitions and contents/3GPP TS 08.18.

5.4.4 Network Service Entity Identifier (NSEI)

The Network Service Entity at the BSS and the SGSN provides the network management functionality required for the operation of the Gb interface. The Network Service Entity is described in 3GPP TS 08.16.

Each Network Service Entity is identified by means of a Network Service Entity Identifier (NSEI). The NSEI together with the BVCI uniquely identifies a BSGP Virtual Connection (e.g. a PTP functional entity) within an SGSN. The NSEI is used by the BSS and the SGSN to determine the NS-VCs that provides service to a BVCI.

5.4.5 BSS Context

The SGSN can provide a BSS with information related to ongoing user data transmission. The information related to one MS is stored in a BSS context. The BSS may contain BSS contexts for several MSs. A BSS context contains a number of BSS packet flow contexts. A BSS packet flow context is identified by a packet flow identifier assigned by the SGSN. There are three pre-defined packet flows identified by three reserved packet flow identifier values. One pre-defined packet flow is used for best-effort service, one for signalling, and one for SMS. The BSS shall not negotiate BSS packet flow contexts for these pre-defined packet flows with the SGSN..