5 Introduction to the Medium Access Control (MAC) procedures

04.603GPPGeneral Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocolRelease 1999TS

5.1 General

The Medium Access Control procedures include the functions related to the management of the shared transmission resources, e.g. the packet data physical channels and the radio link connections on packet data physical channels.

The Medium Access Control procedures support the provision of Temporary Block Flows (TBFs) that allow the point-to-point transfer of signalling and user data within a cell between the network and a mobile station.

Moreover, the Medium Access Control procedures include the procedures for reception of PBCCH and PCCCH, which permits autonomous cell reselection performed by the mobile station (see 3GPP TS 05.08).

5.2 Multiplexing principles

5.2.1 Temporary Block Flow

A Temporary Block Flow (TBF) is a physical connection used by the two RR entities to support the unidirectional transfer of LLC PDUs on packet data physical channels. The TBF is allocated radio resource on one or more PDCHs and comprises a number of RLC/MAC blocks carrying one or more LLC PDUs. A TBF is temporary and is maintained only for the duration of the data transfer (i.e. until there are no more RLC/MAC blocks to be transmitted and, in RLC acknowledged mode, all of the transmitted RLC/MAC blocks have been successfully acknowledged by the receiving entity).

A TBF may operate in either GPRS or EGPRS TBF mode. The network sets the TBF mode in the PACKET UPLINK ASSIGNMENT, PACKET DOWNLINK ASSIGNMENT, or IMMEDIATE ASSIGNMENT message. The EGPRS mode is only supported by EGPRS capable MSs.

If an MS is assigned concurrent TBFs, these shall be in the same TBF mode.

5.2.2 Temporary Flow Identity

Each TBF is assigned a Temporary Flow Identity (TFI) by the network. The mobile station shall assume that the TFI value is unique among concurrent TBFs in the same direction (uplink or downlink) on all PDCHs used for the TBF. The same TFI value may be used concurrently for TBFs on other PDCHs in the same direction and for TBFs in the opposite direction.

An RLC/MAC block associated with a certain TBF shall comprise a TFI. The TBF is identified by the TFI together with, in case of a RLC data block, the direction (uplink or downlink) in which the RLC data block is sent; and in case of a RLC/MAC control message, the direction in which the RLC/MAC control message is sent and the message type.

Global_TFI is used to unambiguously identify the mobile station during packet transfer mode in an uplink or downlink RLC/MAC control message. If present, the Global TFI addresses the MS using either the uplink TFI or downlink TFI of the MS. Which TFI is used is at the discretion of the sender except where explicitly defined by procedure.

5.2.3 Uplink State Flag

An Uplink State Flag (USF) is included in the header of each RLC/MAC block on a downlink PDCH, as specified in clause 10. It may be used by the network to control the multiplexing of different mobile stations on uplink PDCH. The use of USF is further specified in 3GPP TS 05.02.

5.2.4 Medium Access modes

Three medium access modes are supported:

– Dynamic Allocation, characterised by that the mobile station detecting an assigned USF value for each assigned PDCH and block or group of four blocks that it is allowed to transmit on that PDCH (see sub-clause 8.1.1.1);

– Extended Dynamic Allocation characterised by the mobile station detecting an assigned USF value for any assigned PDCH allowing the mobile station to transmit on that PDCH and all higher numbered assigned PDCHs in the same block or group of four blocks (see sub-clause 8.1.1.2);

– Fixed Allocation characterised by fixed allocation of radio blocks and PDCHs in the assignment message without an assigned USF (see sub-clause 8.1.1.3). Fixed Allocation may operate in half duplex mode, characterised by that downlink and uplink TBF are not active at the same time. Half duplex mode is only applicable for multislot classes 19 to 29; and

– Exclusive Allocation, characterised by the mobile station being granted the exclusive right to transmit on the assigned PDCH/H for the duration of an uplink TBF (see sub-clause 8.1.1.3a). Exclusive allocation is applicable only in dual transfer mode.

Either the Dynamic Allocation medium access mode or Fixed Allocation medium access mode shall be supported by all networks that support GPRS. The support of Extended Dynamic Allocation is optional for the network.

The Dynamic Allocation and Fixed Allocation modes shall be supported in all mobile stations. The support of Extended Dynamic Allocation is mandatory for mobile stations of multislot classes 22, 24, 25 and 27. The support of Extended Dynamic Allocation for mobile stations of all other multislot classes are optional and shall be indicated in the MS Radio Access Capability.

The exclusive allocation shall be used in dual transfer mode during uplink operation with a half-rate PDCH.

The network shall ensure that the medium access mode and the resource allocation used for a mobile station is compatible with the multislot class of the mobile station (the MS classes of multislot capability are defined in 3GPP TS 05.02).

NOTE: Different multislot classes may apply for a certain mobile station in packet transfer mode and in dual transfer mode, respectively.

In the case of a downlink transfer, the term medium access mode refers to the measurement time scheduling, for the MS to perform neighbour cell power measurements (see sub-clause 8.1.2.7).

5.2.4a Multiplexing of GPRS and EGPRS mobile stations

GPRS and EGPRS mobile stations can be multiplexed dynamically on the same PDCH.

If dynamic or extended dynamic allocation is used, a mobile station in GPRS TBF mode shall be able to detect the USF that assigns the uplink to that mobile station. The network shall use GMSK modulation, i.e. either CS-1 to CS-4 or MCS-1 to MCS-4, in those blocks. The other blocks may use 8PSK modulation. A mobile station in EGPRS TBF mode shall be able to detect the USF that assigns the uplink to that mobile station. The network may use either GMSK modulation or 8-PSK modulation, i.e. CS-1 to CS-4, MCS-1 to MCS-4 or MCS-5 to MCS-9 in those blocks.

NOTE 1: The stealing bits in the EGPRS GMSK blocks are set to indicate CS-4. The coding and interleaving of the USF is done as defined for CS-4. That leads to:

1) A GPRS mobile station is able to detect the USF in EGPRS GMSK blocks. The risk that the rest of the block will be misinterpreted as valid information is low.

2) An EGPRS mobile station cannot differentiate CS-4 blocks from EGPRS GMSK blocks by decoding the stealing bits only. However, an EGPRS mobile station in EGPRS TBF mode needs only to decode GMSK blocks assuming either of MCS-1 to MCS-4, in order to determine if they were aimed for it.

If fixed allocation is used, uplink blocks of the PDCH are reserved for only one mobile station at a time. Using fixed allocation, there is no particular restriction for the multiplexing of GPRS and EGPRS mobile stations on the same PDCH.

NOTE 2: Due to mobile station synchronisation reasons, special requirements apply for the scheduling, the modulation and coding scheme and the output power of blocks that are transmitted to a mobile station with an active uplink or downlink TBF, see 3GPP TS 05.08.

5.3 Packet idle mode

In packet idle mode no temporary block flow (TBF) exists.

In packet idle mode, the mobile station monitors the relevant paging subchannels on PCCCH, if such is present in the cell. If a PCCCH is not present in the cell, the mobile station monitors the relevant paging subchannels on CCCH.

In packet idle mode, upper layers may require the transfer of a LLC PDU, which implicitly triggers the establishment of a TBF and the transition to packet transfer mode.

In packet idle mode, upper layers may require the establishment of an RR connection. When the mobile station enters dedicated mode (see 3GPP TS 04.18), it may leave the packet idle mode, if the mobile station limitations make it unable to handle the RR connection and the procedures in packet idle mode simultaneously.

5.4 Packet transfer mode

In packet transfer mode, the mobile station is allocated radio resource providing a TBF for a physical point-to-point connection on one or more packet data physical channels for the unidirectional transfer of LLC PDUs between the network and the mobile station. Successive transfer of one or more LLC PDUs is possible. Concurrent TBFs may be established in opposite directions. The RR sublayer provides the following services:

– transfer of LLC PDUs in RLC acknowledged mode;

– transfer of LLC PDUs in RLC unacknowledged mode.

When a transfer of LLC PDUs terminates, in either downlink or uplink direction, the corresponding TBF is released. In packet transfer mode, when all TBFs have been released, in downlink and uplink direction, the mobile station returns to packet idle mode.

In packet transfer mode, upper layers may require the establishment of an RR connection. When the mobile station enters dedicated mode (see 3GPP TS 04.18), it may abort all ongoing TBFs and leave the packet transfer mode, if the mobile station limitations make it unable to handle the RR connection and the procedures in packet transfer mode simultaneously.

5.4a Dual transfer mode

In dual transfer mode, the mobile station is allocated radio resources providing an RR connection on a dedicated traffic channel and a TBF on one or more packet data physical channels. The allocation of radio resources for the RR connection and the TBF is co-ordinated by the network, in agreement with the capabilities of the mobile station in dual transfer mode.

Successive transfer of one or more LLC PDUs is possible. Concurrent TBFs may be established in opposite directions. The transfer of LLC PDUs in RLC acknowledged or RLC unacknowledged mode is provided.

When a transfer of LLC PDUs terminates, in either downlink or uplink direction, the corresponding TBF is released. In dual transfer mode, when all TBFs have been released, in downlink and uplink directions, the mobile station enters dedicated mode.

In dual transfer mode, at the release of the RR connection, the mobile station aborts all ongoing TBFs and enters packet idle mode.

5.5 General procedures in packet idle and packet transfer modes

Unless explicitly stated, the requirements in this sub-clause (5.5 and sub-clauses) apply only in packet idle mode and in packet transfer mode, neither in dedicated mode nor in dual transfer mode.

5.5.1 Mobile station side

The mobile station in either packet idle or packet transfer modes shall monitor the system information broadcast in the cell.

In packet idle mode, the mobile station shall monitor the radio blocks on PCCCH or CCCH, as defined in sub-clauses 5.5.1.5 and 5.5.1.6. The determination of the paging group for the mobile station is defined in 3GPP TS 05.02.

5.5.1.1 Cell reselection

Cell reselection in packet idle and packet transfer modes is specified in 3GPP TS 05.08. The RR entity on the mobile station side indicates to the upper layers the availability of a cell and a cell change when decided by the RR sublayer. Upper layers are advised of system information broadcast in the cell when a new cell has been selected, or when a relevant part of this information changes.

When the mobile station reselects cell, the support of GPRS in the target cell is indicated in system information sent on BCCH, see 3GPP TS 04.08. If the mobile station has received a PBCCH description for the target cell, it shall assume that GPRS is supported, without further receiving system information on BCCH.

NOTE: A PBCCH description for the target cell may be received in the packet system information (neighbour cell information in PSI3 and 3bis) in the old serving cell, or in a BCCH message (SI13) in the target cell.

If a cell supports GPRS, the mobile station may perform packet access. If a cell does not support GPRS, the mobile station is not allowed to perform packet access.

When a cell reselection is determined by the mobile station or ordered by the network, the mobile station may continue its operation in packet idle or in packet transfer mode in the old serving cell, while acquiring certain system information for the target cell.

The operation in the old cell shall be aborted when one of the following conditions are met:

– the mobile station starts to receive information on PBCCH in the target cell;

– the mobile station has received the SI13 message (see 3GPP TS 04.08) and there is no PBCCH present in the target cell; or

– the criteria for camping on the old cell are no longer fulfilled (see 3GPP TS 05.08).

If PBCCH is present in the target cell, the mobile station shall delay the start of receiving information on PBCCH until the first occurrence of PSI1 in block B0. If the reception of PSI1 or PSI2 messages fails (see 5.5.1.2) the mobile station may re-establish and continue its operation in the old cell, until the next occurrence of PSI1 in block B0.

While the operation is maintained in the old cell, the mobile station may suspend its TBF(s) or suspend the monitoring of radio blocks on PCCCH and CCCH, in order to receive necessary information on BCCH in the target cell. Such suspension may be required in both packet idle and packet transfer modes. It is performed without notification to the network.

Suspension of the operation in the old cell for this purpose is allowed during the time required, for each message and according to the mobile station’s multislot class, to receive the required messages on BCCH in the target cell. The allowable suspension of an uplink TBF may be extended with one block period, in case of dynamic or extended dynamic allocation, if the mobile station is unable to receive the corresponding USF due to the suspension of downlink operation.

When the conditions are fulfilled to switch to the new cell, the mobile station shall abort any TBF in progress by immediately ceasing to decode the downlink, ceasing to transmit on the uplink, stopping all RLC/MAC timers except for timers related to measurement reporting. The mobile station shall then switch to the identified specified new cell and shall obey the relevant RLC/MAC procedures on this new cell.

Under no circumstances, operations in the old cell shall be continued more than 5 seconds after a cell reselection has been determined.

5.5.1.1b Release of RR connection

5.5.1.1b.1 General

After the release of an RR connection (see 3GPP TS 04.18, Normal release procedure and Abnormal cases), if the mobile station during the RR connection is unable to monitor the system information broadcast on BCCH or PBCCH (i.e., GPRS class B or GPRS class A mode of operation using DTM), the mobile station shall acquire the system information broadcast in the serving cell. The acquisition of system information shall be performed according to the requirements in sub-clause 5.5.1.2 (PBCCH present in the cell) or sub-clause 5.5.1.3 (PBCCH not present in the cell). The mobile station shall not attempt a packet access or accept a packet downlink assignment before those requirements are fulfilled.

The following exceptions, stated in sub-clauses 5.5.1.1b.2 to 5.5.1.1b.4, may apply.

5.5.1.1b.2 Continuation of PBCCH information

At the establishment of an RR connection and if PBCCH is present in the cell, the mobile station may keep the PSI messages received on PBCCH before the RR connection establishment.

If the RR connection is established, maintained and released in the same serving cell and the MS has received PSI14 messages or received and acted upon PSI1 messages during dual transfer mode at least every 30 seconds such that

– for PSI1, the value of the PBCCH_CHANGE_MARK has indicated no change in the PSI messages (see sub-clause 5.5.1.2.1), and

– for PSI14, all instances of the PSI14 messages indicate no change in the contents of PSI messages, the mobile station may resume the supervision of PBCCH_CHANGE_MARK and update of PBCCH information, defined in sub-clause 5.5.1.2.1, and need not to initiate a complete acquisition of PBCCH information, as specified in sub-clause 5.5.1.2.

5.5.1.1b.3 Continuation of BCCH information

At the establishment of an RR connection and if PBCCH is not present in the cell, the mobile station may keep the SI messages received on BCCH before the RR connection establishment.

If the RR connection is established, maintained and released in the same serving cell and the MS has received PSI14 messages or received and acted upon PSI13/SI13 messages during dual transfer mode at least every 30 seconds such that the value of the BCCH_CHANGE_MARK has indicated no change in the SI messages (see sub-clause 5.5.1.3.1), the mobile station may resume the supervision of BCCH_CHANGE_MARK and update of BCCH information, defined in sub-clause 5.5.1.3.1, and need not to initiate a complete acquisition of BCCH information, as specified in sub-clause 5.5.1.3.

5.5.1.1b.4 Receipt of PSI14 message in dual transfer mode

In dual transfer mode, the mobile station may receive the PSI14 message on PACCH in the serving cell. If the RR connection is released in the same serving cell within 30 seconds after the PSI14 message was last received, the mobile station may use the PSI14 message as a substitute for the SI13 message after the release of the RR connection, until the SI13 message has been received or the mobile station starts to receive information on PBCCH.

The presence of a PBCCH in the cell is indicated by a PBCCH description in the PSI14 message. If the message does not contain the PBCCH description, the mobile station shall assume that PBCCH is not present in the cell.

After the release of the RR connection and if PBCCH is present in the cell, the mobile station shall perform a complete acquisition of PBCCH information, as defined in sub-clause 5.5.1.2.

After the release of the RR connection and if PBCCH is not present in the cell, the mobile station shall perform a complete acquisition of BCCH information, as defined in sub-clause 5.5.1.3. The mobile station shall attempt to receive the SI13 (or PSI13) message within 30 seconds after the last receipt of the PSI14 message.

5.5.1.2 System information on PBCCH

If PBCCH is present in the serving cell, the mobile station shall receive the PACKET SYSTEM INFORMATION (PSI) messages broadcast on PBCCH. The parameters determining the schedule of PSI messages on PBCCH are provided in the PSI1 message.

When a new cell has been selected where PBCCH is present, the mobile station shall perform a complete acquisition of PBCCH messages (see 5.5.1.4). The mobile station shall not perform packet access in the selected cell, or enter the packet transfer mode, until it has:

– acquired the PACKET SYSTEM INFORMATION TYPE 1 (PSI1) message;

– acquired a consistent set of PSI2 messages; and

– made at least one attempt to receive the complete set of PSI messages on PBCCH.

As an option, if the network supports the PACKET PSI STATUS message, the mobile station may perform packet access, and enter packet transfer mode, as soon as the PSI1 message and a consistent set of PSI2 messages have been received. In this case, the mobile station shall implement the request for acquisition of system information (see sub-clause 5.5.1.4.3).

When the PSI1 message has been received, the mobile station shall supervise the PBCCH_CHANGE_MARK and perform update of PBCCH information as specified in sub-clause 5.5.1.2.1. In addition, while camping on a cell, the mobile station shall take into account any PSI message that may be received on PCCCH and PACCH.

Once that the mobile station starts to acquire the information on PBCCH, the information sent to a mobile station in RLC/MAC control messages shall be independent of the information provided on the BCCH. If the mobile station receives information in an RLC/MAC control message that depends on the BCCH information, the behaviour of the mobile station is not specified.

5.5.1.2.1 Supervision of PBCCH_CHANGE_MARK and update of PBCCH information

While camping on a cell where PBCCH is present, the mobile station shall attempt to receive the PSI1 message at least every 30 seconds. The mobile station shall then take into account any occurrence of the PSI1 message that may be received on PACCH during packet transfer mode or on PCCCH during periods in packet idle mode. If the PSI1 message is not received, the mobile station shall attempt to receive this message on PBCCH during periods in packet idle mode.

If the mobile station has not received the PSI1 message within the last 30 seconds, it shall attempt to receive the PSI1 message each time it is scheduled on PBCCH. Such attempts shall be made during both packet idle and packet transfer modes. A mobile station in packet transfer mode may suspend its TBF for this purpose (see sub-clause 5.5.1.4.2).

The PSI1 message contains the PBCCH_CHANGE_MARK and PSI_CHANGE_FIELD parameters. The mobile station shall store the value of the last PBCCH_CHANGE_MARK received.

If the mobile station receives a PBCCH_CHANGE_MARK and detect that the value has been incremented by one unit, compared to the previous value, the mobile station shall perform a partial acquisition of PBCCH information. The information that shall be received is determined by the PSI_CHANGE_FIELD parameter:

– If the PSI_CHANGE_FIELD parameter indicates an update of a specific type or specific types of PSI messages, the mobile station shall receive at least one instance of each of the indicated type(s) of PSI messages.

– If the PSI_CHANGE_FIELD parameter indicates an update of an unspecified type or types of PSI messages, the mobile station shall receive at least one message instance within each consistent set of PSI messages on PBCCH. It shall also receive all PSI messages on PBCCH not belonging to a consistent set.

– If the PSI_CHANGE_FIELD parameter indicates an update of an unknown type of PSI message, the mobile station is not required to receive any PBCCH information.

When a PSI message is received, the mobile station shall consider the PSI change mark value, if such is received in the message and take appropriate action (see sub-clause 5.5.1.4.1).

Whenever the mobile station receives a PBCCH_CHANGE_MARK and detects that the value has been incremented by more than one unit, compared to the previous value, the mobile station shall perform a complete acquisition of PBCCH messages (see sub-clause 5.5.1.4).

5.5.1.2.2 Replacement of PBCCH

The mobile station may receive a PSI1 message indicating that PBCCH is being deactivated in the cell. Moreover, the mobile station may receive a PSI13 message on PACCH or PCCCH providing a different PBCCH description than the one currently being used, or a PSI13 message indicating that PBCCH is not present in the cell.

If the mobile station detects that PBCCH is being deactivated in the cell, or receives an indication that PBCCH is no longer present in the cell, it shall attempt to receive the SI13 message on BCCH. For this purpose, the mobile station may suspend its operation in packet idle and packet transfer modes (see sub-clause 5.5.1.4.2). When the SI13 has been received, further action depends on the contents of the SI13 message:

If the SI13 message contains a PBCCH description, the mobile station shall perform a complete acquisition of PBCCH messages using the indicated PBCCH (see sub-clause 5.5.1.4).

If the SI13 message does not contain a PBCCH description, the mobile station shall perform a complete acquisition of BCCH messages.

If the mobile station receives a PSI13 message with a PBCCH description different from that currently being used, the mobile station shall perform a complete acquisition of PBCCH messages using the new PBCCH.

5.5.1.2.3 PSI1 reception failure

If the mobile station has not received the PSI1 message within the last 60 seconds, a PSI1 reception failure has occurred. A PSI1 reception failure shall result in a cell reselection.

5.5.1.3 System information on BCCH

The presence of a PBCCH in the cell is indicated by a PBCCH description in the SI13 message on BCCH. If the mobile station receives a SI13 message without a PBCCH description, it shall assume that PBCCH is not present in the cell. If PBCCH is not present in the serving cell, the mobile station shall receive the SYSTEM INFORMATION (SI) messages broadcast on BCCH.

When a new cell has been selected where PBCCH is not present, the mobile station shall perform a complete acquisition of BCCH messages (see sub-clause 5.5.1.4). The mobile station shall not perform packet access in the selected cell, or enter the packet transfer mode, until it has:

– acquired the SYSTEM INFORMATION TYPE 3 (SI3), SI13 and, if present, SI1 messages;

– made at least one attempt to receive other SI messages that may be scheduled within one TC cycle on BCCH (see 3GPP TS 05.02).

When the SI13 message has been received, the mobile station shall supervise the BCCH_CHANGE_MARK and perform update of BCCH information.

5.5.1.3.1 Supervision of BCCH_CHANGE_MARK and update of BCCH information

While camping on a cell where PBCCH is not present, the mobile station shall attempt to receive the SI13 or the PSI13 message at least every 30 seconds. The mobile station shall then take into account any occurrence of the PSI13 message that may be received on PACCH during packet transfer mode. If PSI13 is not received, the mobile station shall attempt to receive the SI13 message on BCCH during periods in packet idle mode.

If the mobile station has received neither the SI13 nor the PSI13 message within the last 30 seconds, it shall attempt to receive the SI13 message each time it is scheduled on BCCH. Such attempts shall be made during both packet idle and packet transfer modes. A mobile station in packet transfer mode may suspend its TBF for this purpose (see sub-clause 5.5.1.4.2).

The SI13 and PSI13 messages contain the BCCH_CHANGE_MARK and SI_CHANGE_FIELD parameters. When camped on a cell where PBCCH is not present, the mobile station shall store the value of the last BCCH_CHANGE_MARK received. In that case, if the mobile station detects that the value has been incremented by one unit, compared to the previous value, the mobile station shall perform a partial acquisition of BCCH information. The information that shall be received is determined by the SI_CHANGE_FIELD parameter:

– If the SI_CHANGE_FIELD parameter indicates an update of a specific type or specific types of SI messages, the mobile station shall receive at least one instance of each of the indicated type(s) of SI messages.

– If the SI_CHANGE_FIELD parameter indicates an update of an unspecified type or types of SI messages, the mobile station shall receive at least one message instance within each consistent set of SI messages on BCCH. It shall also receive all SI messages on BCCH not belonging to a consistent set.

– If the SI_CHANGE_FIELD parameter indicates an update of an unknown type of SI message, the mobile station is not required to update any BCCH information.

When a SI message is received, the mobile station shall consider a SI change mark value, if such is received in the message and take appropriate action (see sub-clause 5.5.1.4.1).

If the mobile station detects that the BCCH_CHANGE_MARK value has been incremented by more than one unit, compared to the previous value, the mobile station shall perform a complete acquisition of BCCH messages (see sub-clause 5.5.1.4).

5.5.1.3.2 Establishment of PBCCH

The mobile station may receive a SI13 or PSI13 message providing a PBCCH description indicating that PBCCH is present in the cell. The mobile station shall then perform a complete acquisition of PBCCH messages using the indicated PBCCH (see sub-clause 5.5.1.4).

5.5.1.3.3 SI13 reception failure

If the mobile station has not received the SI13 or the PSI13 message within the last 60 seconds, a SI13 reception failure has occurred. A SI13 reception failure shall result in a cell reselection.

5.5.1.4 Acquisition of system information on the broadcast channel

This procedure shall be used by the GPRS mobile station to perform a complete or partial acquisition of either PBCCH or BCCH information.

This procedure starts:

– when the mobile station is camped on BCCH and receives a BCCH_CHANGE_MARK or SI change mark value indicating that system information is changed.

– when the mobile station is camped on PBCCH and receives a PBCCH_CHANGE_MARK or PSI change mark value indicating that packet system information is changed.

Moreover, the procedure shall start at any other indication, which may be received by the mobile station, that the stored system information for the serving cell is no longer valid.

At cell selection or cell reselection, in case PBCCH is present in the target cell, this procedure starts when the mobile station starts to receive the information on PBCCH. In case PBCCH is not present in the target cell, the procedure starts when the mobile station has received the SI13 message.

In a complete acquisition of either PBCCH or BCCH information, the mobile station shall receive all PSI or SI messages that are scheduled on the respective broadcast channel. The mobile station shall delete any PSI or SI change mark value that was stored before the acquisition of PBCCH or BCCH information started.

In a partial acquisition of either PBCCH or BCCH information, only a certain subset of the PSI or SI messages that are scheduled on the respective broadcast channel shall be received. The mobile station may consider the state of the PSI or SI change mark values, without restriction, to reduce the total number of messages to receive.

When the mobile station acquires a set of PSI or SI messages on the respective broadcast channels, it may receive these messages during both packet idle and packet transfer modes. While the mobile station is in packet idle mode, an attempt to receive a required message shall be made each time the message is scheduled on the broadcast channel, until the message is received. While the mobile station is in packet transfer mode, it shall receive any PSI message that is sent by the network on PACCH.

If the mobile station has not received the required messages within 10 seconds after the start of this procedure, an attempt to receive a missing message shall be made each time the message is scheduled on the broadcast channel. These attempts shall then be performed during both packet idle and packet transfer modes. A mobile station in packet transfer mode may suspend its TBF(s) for this purpose, as specified in sub-clause 5.5.1.4.2.

A second acquisition of either PBCCH or BCCH information may be initiated (e.g., when the mobile station receives a PSI or SI change mark value) before a previous acquisition is completed. In this case, the mobile station shall discard and immediately begin re-acquiring all the system information messages of the particular type to which the changemark value refers.

To allow future extension of PSI message types, the mobile station may disregard a message in a position within the schedule of PSI messages on PBCCH, where it receives a valid RLC/MAC control block, but diagnoses an unknown or unexpected (non-PSI) message type. When this condition is detected, the mobile station needs not to receive the PBCCH block in this position again, until a change in the schedule of PBCCH messages is detected or a complete acquisition of PBCCH information is required.

5.5.1.4.1 Consistent sets of system information messages

A mobile station, receiving a PSI or SI message belonging to a consistent set of system information messages, shall store the last PSI or SI change mark value received for the set of messages (see table 5.5.2.1.4.1). A mobile station lacking all non-GSM capabilities defined for PSI6, PSI7, SI 18 or SI 20 shall consider those message as irrelevant when making a determination of whether or not a consistent set of system information messages has been received.

A mobile station lacking UTRAN capabilities shall consider a PSI3quater message as irrelevant when making a determination of whether or not a consistent set of system information messages has been received.

Whenever mobile station receives a PSI or SI change mark value, which is not equal to the previously stored value for the set of messages, the mobile station shall perform a partial acquisition of either PBCCH or BCCH information. It shall then receive all instances of the PSI or SI messages belonging to the consistent set of system information messages.

If a mobile station detects an inconsistency amongst the PSI or SI count and index parameters within in a consistent set of system information messages or any other inconsistency making the information that is contained invalid, the mobile station shall discard the messages received so far and delete the stored PSI or SI change mark value. The mobile station may then restart the acquisition of the affected system information messages.

5.5.1.4.2 Suspension of operation to receive system information

During certain conditions, the mobile station in packet transfer mode is allowed to suspend a TBF to receive certain information on PBCCH or BCCH. Such suspension is made without notification to the network.

Suspension of a TBF for this purpose is allowed during the time required, for each message and according to the mobile station’s multislot class, to receive the required messages on PBCCH or BCCH. The allowable suspension of an uplink TBF may be extended with one block period, in case of dynamic or extended dynamic allocation, if the mobile station is unable to receive the corresponding USF due to the suspension of downlink operation.

5.5.1.4.3 Request for acquisition of system information

As an option, the mobile station may implement the request for acquisition of system information. If the network supports the PACKET PSI STATUS message, the mobile station may then send the PACKET PSI STATUS message to the network, each time an acquisition of PBCCH information is initiated.

The PACKET PSI STATUS message shall indicate the present status of PSI messages stored in the mobile station. The mobile station shall include as many PSI message types that fit into the Received PSI Message List construction in the PACKET PSI STATUS message and that meet the following criteria:

– The PSI message type shall be relevant for the mobile station, based on the features the mobile station supports (e.g., non-GSM and multi-RAT capabilities); and

– In case of optional PSI messages types, the PSI message type shall be indicated by the network as present on PBCCH.

The message type value for these PSI messages shall be included in the Received PSI Message List in the Packet PSI STATUS message. The network may use this information to determine which PSI message types the mobile station is able to receive and the present status of the PSI messages stored in the mobile station.

During a partial acquisition of PSI messages, see sub-clause 5.5.1.4, the mobile station may need to obtain the current PSI change mark value for certain types of PSI messages. In that case, the mobile station may use this procedure and indicate the present status for that PSI message type in the PACKET PSI STATUS message, except that the message instance corresponding to the PSI index parameter = 0 shall be indicated as not received.

The PACKET PSI STATUS message is sent on PACCH when the mobile station is in packet transfer mode. The first sending of this message during the acquisition of PBCCH information shall take place at the first suitable opportunity after the acquisition is initiated.

During the acquisition of PBCCH information, the PACKET PSI STATUS message may be sent up to four times to the network. The second sending of this message shall take place at the first suitable opportunity at least 1 second after that the message is sent the first time. Further sendings shall take place at the first suitable opportunity at least 2 seconds after that the message was sent the previous time.

The PACKET PSI STATUS message shall not be sent when the mobile station has started to suspend its TBF(s) in order to receive the required PSI messages on PBCCH. The PACKET PSI STATUS message shall not be sent when the mobile station has acquired the complete set of PSI messages on PBCCH.

5.5.1.5 Discontinuous reception (DRX)

A mobile station in packet idle mode shall listen to the radio blocks on CCCH or PCCCH as defined in 3GPP TS 05.02. In the GPRS attach procedure, defined in 3GPP TS 24.008, the mobile station requests values for the SPLIT_PG_CYCLE and NON_DRX_TIMER parameters to be applied on CCCH or PCCCH.

NOTE: The support of the SPLIT_PG_CYCLE parameter is optional on CCCH, see 3GPP TS 05.02.

The SPLIT_PG_CYCLE and NON_DRX_TIMER parameters control:

– the occurrence of paging blocks on CCCH or PCCCH belonging to the mobile station (SPLIT_PG_CYCLE parameter, see 3GPP TS 05.02) in DRX mode (see 3GPP TS 03.64); and

– the duration of the non-DRX mode period to be applied by the mobile station when it has left the packet transfer mode or the dual transfer mode and then enters the packet idle mode.

There are four cases when the mobile station shall enter a non-DRX mode period.

1) At the transition from the packet transfer mode to the packet idle mode, the mobile station shall enter the Transfer non-DRX mode period.

2) At the transition from the dual transfer mode to the dedicated mode or packet idle mode, the mobile station shall enter the Transfer non-DRX mode period.

In both cases, the duration of the Transfer non-DRX mode period is determined by value of the NON_DRX_TIMER parameter, requested in the GPRS attach procedure, and the value of the DRX_TIMER_MAX parameter broadcast in the cell. The mobile station may use the minimum value of these two parameters.

If the mobile station receives a new value of the DRX_TIMER_MAX parameter during the Transfer non-DRX mode period, the mobile station may wait to apply the new value until the next time the Transfer non-DRX mode period is entered.

3) A mobile station operating in NC2 mode shall enter the NC2 non-DRX mode period when it sends an NC measurement report. The duration of this period is defined by the NC_NON_DRX_PERIOD parameter.

4) When initiating the MM procedures for GPRS attach and routeing area update defined in 3GPP TS 04.08, the mobile station shall enter the MM non-DRX mode period. This period ends when either of the messages GPRS ATTACH ACCEPT, GPRS ATTACH REJECT, ROUTING AREA UPDATE ACCEPT or ROUTING AREA UPDATE REJECT is received by the mobile station. This period also ends after timeout when waiting for any of these messages.

The non-DRX mode periods defined above run independent of each other and may overlap. The non-DRX mode periods have effect only in packet idle mode. In packet idle mode, the mobile station shall be in non-DRX mode during any of the non-DRX mode periods. Otherwise, the mobile station in packet idle mode may be in DRX mode.

If the mobile station establishes a dedicated connection during any of the non-DRX mode periods, then that period shall continue to run.

5.5.1.6 Page mode procedures on PCCCH

The network sends page mode information in all downlink message on PCCCH (and PACCH, see NOTE 1). The page mode information controls possible additional requirements on a mobile station receiving the message.

NOTE 1: PCCCH, PDTCH and PACCH may be operated in frame stealing mode on the same PDCH. A mobile station in packet idle mode shall consider any RLC/MAC control message received in such a radio block as belonging to PCCCH. A mobile station in packet transfer mode or dual transfer mode shall consider any RLC/MAC control message received as belonging to PACCH.

A mobile station in packet transfer mode or dual transfer modeshall not consider the page mode information received in any message that is received on a PDCH.

A mobile station in packet idle mode shall take into account the page mode information in any message received in a radio block on PCCCH corresponding to its paging group. The mobile station shall not take into account the page mode information in a message received in any other radio block than those corresponding to its paging group. The requirements yielded by the page mode information are as follows:

normal paging: no additional requirements;

extended paging: the mobile station is required in addition to receive and analyse the possible message in the third block period on PCCCH where paging may occur (PPCH), following the block corresponding to MS’s paging group;

paging reorganization: The mobile station shall receive all messages on the PCCCH regardless of the BS_PAG_BLKS_RES setting. It is required to receive all PBCCH messages. When the mobile station receives the next message to its (possibly new) paging group, subsequent action is defined by the page mode information in that message;

same as before: no change of page mode from the previous page mode.

Note that a mobile station takes into account the page mode information only in packet idle mode and only in messages received in a radio block corresponding to its paging group, whatever the currently applied requirements are (normal paging, extended paging or paging reorganization).

When the mobile station selects a new PPCH, the initial page mode in the mobile station shall be set to paging reorganization. If an RLC/MAC block in a paging sub-channel does not contain page mode information, or if it is not received correctly, the default page mode information is same as before.

5.5.1.7 Frequency Parameters

Frequency parameters may be included in the packet assignment messages (i.e., PACKET DOWNLINK ASSIGNMENT, PACKET UPLINK ASSIGNMENT, and PACKET TIMESLOT RECONFIGURE messages) and define the radio frequency channels or set of radio frequency channels the mobile station is to use during the assigned TBF. The first assignment message, sent to the mobile station when it enters packet transfer mode, shall include the frequency parameters. Subsequent assignment messages, sent to the mobile station during packet transfer mode, may omit the frequency parameters. If a mobile station receives a subsequent assignment message, during packet transfer mode, without the frequency parameters, the mobile station shall continue to use the previously assigned frequency parameters.

NOTE 1: A packet assignment message, when sent to a mobile station in dual transfer mode, shall not include the frequency parameters. If the network intends to change the frequency allocation of a mobile station in dual transfer mode, the network may use the DTM assignment procedure defined in 3GPP TS 04.18.

The Frequency Parameters information element is defined in sub-clause 12.8. The frequency parameters may use an ARFCN defining a non-hopping radio frequency channel, or use the indirect encoding, direct encoding 1 or direct encoding 2 defining a hopping radio frequency channel.

The indirect encoding defines the assigned set of radio frequency channels by referencing information stored within the mobile station. Such information may be received on PBCCH or BCCH (see sub-clauses 5.5.2.1, 11.2.19, 12.8 and 12.10a), or be received in a previous assignment message using one of the direct encoding options. An MA_NUMBER identifies which of up to eight stored sets of frequency parameters is to be used. The MA_NUMBER shall use the following coding:

MA_NUMBER = 0–13 shall be used to reference a GPRS mobile allocation received in a PSI2 message;

MA_NUMBER = 14 shall be used to reference a GPRS mobile allocation received in a SI13 or PSI13 message;

MA_NUMBER = 15 shall be used to reference a GPRS mobile allocation received in a previous assignment message using the direct encoding.

When the indirect encoding is used, the network may include a CHANGE_MARK_1 and a CHANGE_MARK_2 in the Frequency Parameters information element. The mobile station shall then verify that it is using a set of PBCCH or BCCH information identified by a PSI or SI change mark corresponding to one of the CHANGE_MARK_1 or 2 parameters, for the decoding of the frequency information. If that is not the case, an abnormal condition occurs.

The direct encoding defines the assigned set of radio frequency channels by using information contained within the assignment message. The direct encoding 1 references the cell allocation or reference frequency lists received on PBCCH for the decoding of this information. The direct encoding 2 is self contained. When the direct encoding 1 or 2 is used, the mobile station shall store the received GPRS mobile allocation for possible later reference in an assignment message using the indirect encoding. Such reference shall be made using the MA_NUMBER = 15.

NOTE 2: If there is a GPRS mobile allocation associated with MA_NUMBER = 15, the association shall be kept unchanged if the mobile station receives a packet assignment using the indirect encoding (referencing any value of the MA_NUMBER), the frequency parameters are not included in the packet assignment (i.e., in packet transfer mode or dual transfer mode) or the mobile station establishes a dedicated connection.

For the decoding of frequency parameters, the mobile station shall be able to store the following frequency information (see sub-clauses 11.2.19, 12.8 and 12.10a):

– four Reference Frequency Lists received in the PSI2 information and the corresponding RFL_NUMBERs for identification, each RFL having a contents length of up to 18 octets;

– a Cell Allocation received in the PSI2 information referencing up to four RFLs;

– seven GPRS Mobile Allocations received in the PSI2 or the SI13/PSI13 information and the corresponding MA_NUMBERs for identification, each GPRS Mobile Allocation information element having a length of up to 12 octets (96 bits); and

– one GPRS mobile allocation received in an assignment message using direct encoding 1 or 2, consisting of either a GPRS Mobile Allocation information element having a length of up to 12 octets (96 bits) or a MA Frequency List having a contents length of up to 18 octets.

The mobile station shall be able to store the frequency information for the PCCCH description corresponding to its own PCCCH_GROUP (see sub-clause 11.2.19).

If the mobile station supports SMSCB, is shall be able to store the frequency information for the CBCH, to be used in packet idle mode.

The frequency information that the mobile station has stored while camping on a cell shall be deleted when the mobile station reselect cell.

5.5.1.8 TLLI management

In case the mobile station receives a message assigning a new P-TMSI from the network during the contention resolution procedure, the mobile station shall continue to use the old TLLI until the contention resolution is completed.

After contention resolution the mobile station shall apply new TLLI in RLC/MAC control block if the mobile has received a new P-TMSI.

5.5.1.9 Packet Flow Context (PFC)

Packet Flow Context (PFC) procedures are described in 3GPP TS 23.060. A Packet Flow Identifier (PFI) is used to identify a PFC.

Network support of packet flow context (PFC) procedures is indicated by the PFC_FEATURE_MODE parameter that is broadcast on either the BCCH or PBCCH. If the PFC_FEATURE_MODE bit is not present then the network does not support PFC procedures. If the network supports PFC the mobile station may indicate a PFI value during uplink TBF establishment. The PFI value identifies the initial PFC used during the TBF.

5.5.2 Network side

5.5.2.1 System Information broadcasting

5.5.2.1.1 System information on PBCCH

If PBCCH is present in the cell, the network regularly broadcasts PACKET SYSTEM INFORMATION TYPE (PSI) 1, 2, 3 and 3bis messages, and optionally PSI3ter, PSI3quater and some types of PSI messages on the PBCCH. The PSI 2, PSI 3bis, PSI3 ter, PSI3quater messages and some further types of PSI messages may be broadcast in multiple number of instances. Based on the information broadcast in PSI messages, the mobile station is able to decide whether and how it may gain access to the system via the current cell.

NOTE: The network should take into account the limitations of earlier version of mobile equipments to understand the 3-digit MNC format of the location area identification, see sub-clause 12.23 and 3GPP TS 04.08, Table "Location Area Identification .information element".

Instances of the PSI 4 message are broadcast on PBCCH if the mobile stations camping on the cell shall perform interference measurements for power control, see 3GPP TS 05.08.

Instances of the PSI 5 message are broadcast on PBCCH if the mobile stations camping on the cell shall perform measurement reporting, see 3GPP TS 05.08.

Instances of the PSI6 and PSI7 message may be broadcast on the PBCCH if non-GSM broadcast information is transmitted.

The PSI8 message may be broadcast on the PBCCH if additional information (i.e. CBCH configuration) shall be provided to the mobile station camping on the cell.

The PSI1 message contains the PBCCH_CHANGE_MARK and PSI_CHANGE_FIELD parameters. The value of the PBCCH_CHANGE_MARK may be incremented by one, modulo 8, each time the network makes a change in the PBCCH information. Such change includes any addition, removal or replacement of PSI messages, contents of PSI messages, or change in the scheduling of PSI messages on PBCCH. A change in the contents of the PSI1 message alone shall not to be reflected in the PBCCH_CHANGE_MARK. When the PBCCH_CHANGE_MARK is incremented, the PSI_CHANGE_FIELD parameter shall be set to an appropriate value to indicate the nature of the latest change in the PBCCH information.

The network may increment the PBCCH_CHANGE_MARK value by more than one, modulo 8, in order to enforce a complete acquisition of PBCCH information of all mobile stations.

In order to avoid extensive TBF suspensions following an increment of the PBCCH_CHANGE_MARK parameter, the network may send PSI messages on PACCH to mobile stations in packet transfer mode.

The network indicates the support of the PACKET PSI STATUS and EGPRS PACKET CHANNEL REQUEST messages in the PSI1 message.

5.5.2.1.2 System information on BCCH

In addition to the requirements in 3GPP TS 04.08, a SYSTEM INFORMATION TYPE 13 (SI13) message is regularly broadcast by the network on the BCCH to support GPRS. Optionally and if PBCCH is not present in the cell, additional types of SI messages may be broadcast on BCCH. Some of them may be broadcast in multiple number of instances. If PBCCH is present in the cell, only the SI13 message is required on BCCH to support GPRS.

Based on this information, the GPRS mobile station is able to decide whether and how it gains access to the system via the current cell when PBCCH is not present.

The SI13 message contains the BCCH_CHANGE_MARK and SI_CHANGE_FIELD parameters. If PBCCH is not present in the cell, the value of the BCCH_CHANGE_MARK may be incremented by one, modulo 8, each time the network makes a change in the BCCH information. Such change includes any addition, removal or replacement of SI messages, contents of SI messages, or change in the scheduling of SI messages on BCCH. Changes in the contents of the SI13 message shall not to be reflected in the BCCH_CHANGE_MARK. Changes of the contents of the RACH Control Parameters information element alone (see 3GPP TS 04.08) may optionally be reflected in the BCCH-CHANGE-MARK ; if reflected, the SI-CHANGE-FIELD parameter may indicate only one of the SI message containing the RACH Control Parameters. When the BCCH_CHANGE_MARK is incremented, the SI_CHANGE_FIELD parameter shall be set to an appropriate value to indicate the nature of the latest change in the BCCH information.

When PBCCH is not present in the cell, the network may increment the BCCH_CHANGE_MARK value by more than one, modulo 8, in order to enforce a complete acquisition of BCCH information of all mobile stations.

If PBCCH is not present in the cell, instances of the SI 18 and SI 20 message may be broadcast on the BCCH if non-GSM broadcast information is transmitted.

5.5.2.1.3 System information on PACCH (and other logical channels)

The network may broadcast PSI messages on PACCH. In particular, if a mobile station is busy in packet transfer mode and thus unable to receive the relevant blocks on the broadcast channels (PBCCH or BCCH) for a period longer than 15 seconds, the following requirements apply:

– If PBCCH is present in the cell, the network may broadcast the PSI1 message on PACCH such that the mobile station may receive the PSI1 message at least every 15 seconds.

– If PBCCH is not present in the cell, the network may broadcast the PSI13 message on PACCH such that the mobile station may receive the PSI13 messages at least every 15 seconds.

Furthermore, the network may broadcast PSI messages on PCCCH. In particular, the network may send the PSI1 and PSI13 messages on PCCCH to notify mobile stations in packet idle mode about changes in the PBCCH information or changes of the PBCCH channel description.

If the network supports the PACKET PSI STATUS message and this message is received from a mobile station, the network may schedule the missing PSI messages for that mobile station on PACCH.

The network may send the PSI14 message on PACCH to a mobile station in dual transfer mode. The scheduling of the PSI14 message is determined by the network.

If PBCCH is present in the cell and the network changes the contents of any of the PSI messages, it shall set the PSI_CHANGED_IND to “1” in all the PSI14 messages it sends in the next 30 seconds. Otherwise, the PSI_CHANGED_IND shall be set to “0”.

When a PSI or SI message is received on PACCH during dual transfer mode, no parameters except those relevant for monitoring possible changes in the contents of SI or PSI messages (e.g. PBCCH_CHANGE_MARK, BCCH_CHANGE_MARK, PSI_CHANGED_IND) shall be applied by the MS for operation in dual transfer mode.

5.5.2.1.4 Consistent sets of system information messages

Certain types of PSI and SI messages are sent on PBCCH and BCCH in a multiple number of instances. If such a PSI or SI message type is sent on (P)BCCH, the mobile station shall receive a consistent set of that type of PSI or SI message. In some cases, more than one type of PSI messages may be joined into one consistent set, see table 5.5.2.1.4.1.

Table 5.5.2.1.4.1: Consistent sets of system information messages

Consistent set /
Message Type(s)

Broadcast
Channel

Number of instances

PSI or SI change mark
parameter

PSI or SI index
parameter

PSI or SI count
parameter

PSI2

PBCCH

1 – 8

PSI2_CHANGE_MARK

PSI2_INDEX

PSI2_COUNT

PSI3

PBCCH

1

PSI3_CHANGE_MARK

PSI3 bis

PBCCH

1 – 16

PSI3_CHANGE_MARK

PSI3bis_INDEX

PSI3bis_COUNT

PSI3 ter

PBCCH

0 – 16

PSI3_CHANGE_MARK

PSI3ter_INDEX

PSI3ter_COUNT

PSI3 quater

PBCCH

0 – 16

PSI3_CHANGE_MARK

PSI3quater_INDEX

PSI3quater_COUNT

PSI4

PBCCH

0 – 8

PSI4_CHANGE_MARK

PSI4_INDEX

PSI4_COUNT

PSI5

PBCCH

0 – 8

PSI5_CHANGE_MARK

PSI5_INDEX

PSI5_COUNT

PSI6

PBCCH

0 – 8

PSI6_CHANGE_MARK

PSI6_INDEX

PSI6_COUNT

PSI7

PBCCH

0 – 8

PSI7_CHANGE_MARK

PSI7_INDEX

PSI7_COUNT

PSI8

PBCCH

0 – 8

PSI8_CHANGE_MARK

PSI8_INDEX

PSI8_COUNT

SI13 (Note 1, 2)

BCCH

1

SI13_CHANGE_MARK

SI2 ter

BCCH

0 – 8

SI2ter_MP_CHANGE_MARK and SI2ter_3G_ CHANGE_MARK

SI2ter_INDEX

SI2ter_COUNT

SI2 quater

BCCH

0 – 16

BA_IND, 3G_BA_IND and MP_CHANGE_MARK

SI2quater_INDEX

SI2quater_COUNT

SI18

BCCH

0 – 8

SI18_CHANGE_MARK

SI18_INDEX

None (Note 4)

SI19

BCCH

0 – 8

SI19_CHANGE_MARK

SI19_INDEX

None (Note 4)

SI20

BCCH

0 – 8

SI20_CHANGE_MARK

SI20_INDEX

None (Note 4)

NOTE 1: If the SI13 message provides a GPRS mobile allocation, it shall also provide an SI13_CHANGE_MARK. The SI13_CHANGE_MARK shall be used if the indirect encoding of the frequency information is applied in a packet assignment, referring to the GPRS mobile allocation provided in the SI13 message. There is only one instance of the SI13 message.

NOTE 2: The PSI13 message may be received on PACCH. It provides the same information as SI13, including the SI13_CHANGE_MARK.

NOTE 3: If PSI2 and SI13 change mark values need to be distinguished, e.g., during an activation or release of PBCCH, the network should assign appropriate values to these parameters.

NOTE 4: For SI18, SI19 and SI20 messages, there is no count parameter (see 3GPP TS 04.18).

A consistent set of system information messages is identified by a PSI or SI change mark parameter included in each message in the set. All messages within a consistent set shall have the same value of this parameter.

The total number of system information messages of a certain type within a consistent set is indicated by a PSI or SI count parameter included in each message in the set. The position of a certain message instance within the consistent set of system information messages is indicated by a PSI or SI index parameter.

The PSI or SI count parameter shall have the value N–1, where N is the number of instances of the particular message type present in the consistent set. The PSI or SI index parameter shall have a range from zero to N–1. Different instances of a particular message type in a consistent set shall have different values of the PSI or SI index parameter.

5.5.2.2 Paging

The network is required to send valid RLC data blocks or RLC/MAC control blocks continuously on all subchannels on PCCCH where paging can appear.

5.6 Measurement reports

The network may request measurement reports from the MS. The measurement reporting principles are specified in 3GPP TS 05.08. The measurement reports can be of two types:

– Network Control (NC) measurement reports when the MS is in MM Ready state (see 3GPP TS 24.008); this may be performed with either the PACKET MEASUREMENT REPORT message or the PACKET ENHANCED MEASUREMENT REPORT message;

– Extended measurement (EM) reports in packet idle mode.

5.6.1 Network Control (NC) measurement reporting

The behaviour of the mobile station is controlled by the parameter NETWORK_CONTROL_ORDER broadcast in the PSI5 message on PBCCH, in the SI13 and SI2quater messages on the BCCH and in the PSI13 message on PACCH. Alternatively, the network may send the NETWORK_CONTROL_ORDER parameters in a PACKET MEASUREMENT ORDER or in a PACKET CELL CHANGE ORDER message on PCCCH or PACCH to a particular mobile station . The parameter NETWORK_CONTROL_ORDER may have one of the values NC0, NC1, NC2 or RESET, see 3GPP TS 05.08.

When in mode NC1 or NC2, the mobile station shall perform the NC measurements as defined in 3GPP TS 05.08. The reporting periods are indicated in the NC_REPORTING_PERIOD_I and NC_REPORTING_PERIOD_T field of the PSI5, the SI2quater, the PACKET CELL CHANGE ORDER or the PACKET MEASUREMENT ORDER message. If NC_NON_DRX_PERIOD, NC_REPORTING_PERIOD_I or NC_REPORTING_PERIOD_T have not been received by the mobile station the default values shall be used. The mobile station shall apply to the timer T3158 either the NC_REPORTING_PERIOD_I when in packet idle mode or the NC_REPORTING_PERIOD_T when in packet transfer mode. The measurement results shall be sent to the network using the procedures specified in sub-clause 7.3 for packet idle mode, and in sub-clause 8.3 for packet transfer mode.

On expiry of timer T3158, the mobile station shall restart timer T3158 with the indicated reporting period, perform the measurements and send either the PACKET MEASUREMENT REPORT message or the PACKET ENHANCED MEASUREMENT REPORT to the network. The condition for sending the PACKET ENHANCED MEASUREMENT REPORT message instead of the PACKET MEASUREMENT REPORT message is based on the REPORT_TYPE parameter and if the MS has received BSIC information for all cells. For the detailed conditions see sub-clauses 11.2.23, 11.2.4 and 11.2.9b ("Packet System Information Type 5, Packet Cell Change Order, and Packet Measurement Order") and also 3GPP TS 04.18 sub-clause 10.5.2.33b ("SI 2quater Rest Octets").

A mobile station in mode NC1 or NC2 may receive a new indicated reporting period or change packet mode while timer T3158 is active. If the new indicated reporting period is less than the time to expiry of timer T3158, the mobile station shall immediately restart timer T3158 with the new indicated reporting period. Otherwise, the timer T3158 shall continue to run.

When the mobile station leaves the MM Ready state, the timer T3158 shall be stopped and no more measurement reports shall be sent to the network.

A mobile station may reselect a new cell or may be ordered to reselect a new cell with mode NC1 or NC2 while timer T3158 is active. If time to expiry of timer T3158 is greater than the indicated reporting period for the new cell, the mobile station shall immediately restart timer T3158 with the indicated reporting period for the new cell. Otherwise, the timer T3158 shall continue to run.

At cell reselection the NC measurement parameters valid for the mobile station in the new cell (NETWORK_CONTROL_ORDER, NC_NON_DRX_PERIOD, NC_REPORTING_PERIOD_I and NC_REPORTING_PERIOD_T) are either:

– brought from the old cell (if received in a PACKET MEASUREMENT ORDER or PACKET CELL CHANGE ORDER message, see 3GPP TS 05.08); or

– received in a broadcast PSI5, SI13, PSI13 or SI2quater message in the new cell. If no parameters have been brought from the old cell, and until individual measurement parameters are received in the new cell, the mobile station shall use the broadcast measurement parameters from PSI5 if a PBCCH is allocated in the cell or SI2quater if a PBCCH is not allocated in the cell or use the default parameter values.

The default frequency list to be applied in the new cell shall be the BA(GPRS) list of that cell until a new PACKET MEASUREMENT ORDER message is received. The BA(GPRS) list could also have been modified by frequency parameters received in a PACKET_CELL_CHANGE_ORDER message in the old cell.

For (NC) measuremenr reporting, the Mobile Station shall use PACKET ENHANCED MEASUREMENT REPORT messages instead of PACKET MEASUREMENT REPORT messages if that is indicated by the parameter REPORT_TYPE and if at least one BSIC is allocated to each frequency in the BA(GPRS) list.

For a multi-RAT mobile station, reports on 3G cells may also be included in the reporting. For report with the PACKET MEASUREMENT REPORT message, reporting is performed on two separate lists: the BA(GPRS) and the 3G Neighbour Cell List (for a multi-RAT MS). For report with the PACKET ENHANCED MEASUREMENT REPORT message, reporting is performed on the Neighbour Cell List (defined in sub-clause 5.6.3.3).

A mobile station involved in an RR connection (in class A mode of operation), shall not send measurement reports to the network during that period. The mobile station shall return to the previous mode when the RR connection is released.

5.6.2 Extended measurement (EM) reporting

The network may order a mobile station to send extended measurement reports. The behaviour of the mobile station is controlled by the parameter EXT_MEASUREMENT_ORDER in the PSI5 or PACKET MEASUREMENT ORDER message. The network may broadcast the PSI5 message on PBCCH to address all mobile stations or send the PACKET MEASUREMENT ORDER message on PCCCH or PACCH to address a particular mobile station as defined in sub-clauses 7.5 and 8.5. The parameter EXT_MEASUREMENT_ORDER shall have one of the values EM0, EM1 or RESET, see 3GPP TS 05.08.

When in mode EM1 the mobile station shall perform the measurements as defined in 3GPP TS 05.08. The EXT_REPORTING_PERIOD field of the PSI5 or PACKET MEASUREMENT ORDER message indicates reporting period. When instructed to perform EM measurement reporting the mobile station shall start timer T3178 according to the indicated reporting period. The results shall be sent to the network using the procedure defined in sub-clause 7.3 or 8.3.

A mobile station may reselect to a new cell with mode EM1while timer T3178 is active. If the time to expiry of timer T3178 is greater than the indicated reporting period for the new cell, the mobile station shall immediately restart timer T3178 with the indicated reporting period for the new cell. Otherwise, the timer T3178 shall continue to run.

5.6.3 Additional measurement and reporting parameters

Some parameters from the PACKET MEASUREMENT ORDER, PACKET CELL CHANGE ORDER, SI2quater, PSI3bis, PSI3ter, PSI3quater or PSI5 messages allow to build GPRS Measurement Parameters, GPRS 3G Measurement Parameters and neighbour cell lists which are used for Network Control (NC) measurement reporting.

5.6.3.1 Deriving the 3G Neighbour Cell list from the 3G Neighbour Cell description

In a cell without a PBCCH allocated, the 3G Neighbour Cell list is given by one or more instances of the SI2quater message with the same 3G_BA_IND value.

In a cell with a PBCCH allocated, the 3G Neighbour Cell list is given by one or more instances of the PSI3quater message with the same PSI3_CHANGE_MARK and 3G_BA_IND values.

The 3G Neighbour cell list may be modified by a PACKET CELL CHANGE ORDER message (in which case the reference list is given on the new cell) or by one or more instances of the PACKET MEASUREMENT ORDER message with the same 3G_BA_IND value or PSI3_CHANGE_MARK value.

The 3G Neighbour Cell list may contain up to 96 3G Neighbour Cells and/or UTRAN frequencies for RSSI reporting.

Each 3G Neighbour Cell Description received is added to the 3G Neighbour Cell list, starting with the index equal to the parameter Index_Start_3G. If this parameter is not present then the value 0 shall be used.

For each 3G Neighbour Cell Description received, the cells / UTRAN frequencies are indexed in the following order:

1 UTRAN FDD cells / UTRAN FDD frequencies: FDD UARFCNs are indexed in the order of occurrence in the 3G Neighbour Cell description. For each FDD UARFCN indicating UTRAN FDD cells, the cells are indexed in the order of increasing values of the decoded FDD_CELL_INFORMATION parameters.

2 UTRAN TDD cells / UTRAN TDD frequencies: TDD UARFCNs are indexed in the order of occurrence in the 3G Neighbour Cell description. For each TDD UARFCN indicating UTRAN TDD cells, the cells are indexed in the order of increasing values of the decoded TDD_CELL_INFORMATION parameters.

If more than one cell / UTRAN frequency with the same index in the 3G Neighbour Cell list are provided by different instances of 3G Neighbour Cell descriptions, the cell / UTRAN frequency from the message instance with the highest index shall be used. In case the same 3G Cell / UTRAN frequency occurs more than once in the resulting 3G Neighbour Cell list, each occurrence shall be assigned an index but only the cell / UTRAN frequency with the highest index in the 3G Neighbour Cell list shall be referred to in measurement reports.

The 3G Neighbour Cell Description may contain information on 3G Neighbour Cells / UTRAN frequencies to be removed (REMOVED_3GCELL_Description). The cells / UTRAN frequencies to be removed are identified by their indices in the 3G Neighbour Cell list. Removed cells / UTRAN frequencies shall keep their indices but no measurement shall be performed. If the index is higher than 95 or points to a 3G cell / UTRAN frequency that does not exist, this shall not be considered as an error.

In a cell without PBCCH allocated, the mobile station shall only combine 3G Neighbour cells / UTRAN frequencies from SI2quater messages indicating the same value of the 3G_BA_IND without any message indicating a different value of the 3G_BA_IND received in between.

In a cell with a PBCCH allocated, the mobile station shall only combine 3G Neighbour cells / UTRAN frequencies from PSI3quater messages indicating the same PSI3_CHANGE_MARK value.

If a 3G Neighbour Cell Description includes non-supported frequencies or Radio Access Technologies or if the same cell / UTRAN frequency occurs more than once, this shall not be considered as an error; indices in the 3G neighbour Cell list shall be incremented accordingly. If a cell / UTRAN frequency is provided for an index higher than 95 in the 3G Neighbour Cell list, this shall not be considered as an error; the cell / UTRAN frequency shall not be included in the 3G Neighbour Cell list.

The MS behaviour is not specified if the number of 3G frequencies or cells exceeds the MS monitoring capabilities as defined in 3GPP TS 05.08.

5.6.3.2 Deriving BA(GPRS) and the GSM Neighbour Cell list

In a cell without a PBCCH allocated, BA(GPRS) is equal to the BA (list) from the SI2/SI2bis/SI2ter messages. BSICs from the GPRS BSIC Description from one or more instances of the SI2quater message (if broadcast) shall be associated with BA(GPRS) with the same BA_IND value to create the GSM Neighbour Cell list, as described in 3GPP TS 04.18 (sub-clause 3.4.1.2.1.2, "Deriving the GSM Neighbour Cell list from the BSIC and the BA (list)"). If GPRS BSIC Description is not broadcast, the GSM Neighbour Cell list is equal to BA(GPRS) (only a frequency list).

In a cell with a PBCCH allocated, BA(GPRS) is derived from the neighbour cell parameters sent in PSI3 and ascending order of PSI3bis on PBCCH with the same PSI3_CHANGE_MARK value (see 11.2.20). Each neighbour cell listed in PSI3 and in one or more instances of PSI3bis is assigned an ascending index used for measurement reports. The first neighbour cell in PSI3 has the lowest index (= 0), and the last neighbour cell in the highest indexed PSI3bis message has the highest index. The GSM Neighbour Cell list is equal to BA(GPRS).

The GSM Neighbour Cell list may contain up to 96 GSM Neighbour Cells. The total number of GSM frequencies to measure shall not exceed 32. If the list includes more than 32 frequencies, the MS shall only measure the 32 frequencies with the lowest indices.

The GSM Neighbour Cell list may be modified by "NC Frequency List" in a PACKET CELL CHANGE ORDER message (in which case the reference list is given on the new cell) or one or more instances of the PACKET MEASUREMENT ORDER message with the same BA_IND value or PSI3_CHANGE_MARK value.

The "NC Frequency List" may add cells to the GSM Neighbour Cell list (see sub-clause 11.2.4 and 11.2.9b, "PACKET CELL CHANGE ORDER" and "PACKET MEASUREMENT ORDER"). These cells shall be added at the end of the GSM Neighbour Cell list and indexed in the order of occurrence within the PACKET CELL CHANGE ORDER message or ascending instances of the PACKET MEASUREMENT ORDER message. The list of added cells may contain GPRS cell re-selection parameters.

In case the same cell (ARFCN+BSIC) or the same ARFCN without BSIC occur more than once in the resulting GSM Neighbour Cell list, each occurrence shall be assigned an index but only the cell with the highest index shall be used for cell re-selection and referred to in measurement reports.

The "NC Frequency List" may delete frequencies from the BA(GPRS) list (see 11.2.9b). The frequencies to be removed are identified by their indices in the BA(GPRS). In this case all cells associated with the removed frequencies shall be removed from the GSM Neighbour Cell list. Removed cells/frequencies shall keep their indices but no measurements or reporting shall be performed. If the index points to a cell that does not exist, this shall not be considered as an error.

If the mobile station receives a PACKET MEASUREMENT ORDER message (full set of instances) with changed PMO_IND parameter value, any old "NC frequency list" shall be deleted. If the last PACKET MEASUREMENT ORDER message (full set of instances) does not contain a "NC frequency list" (no added or deleted frequencies) the mobile station shall return to BA(GPRS).

In a cell without PBCCH allocated, if the BA_IND parameter is changed, the mobile station shall re-read and rebuild the GSM Neighbour Cell list.

In a cell with a PBCCH allocated, if PSI3_CHANGE_MARK is changed, the mobile station shall re-read and rebuild the GSM Neighbour Cell list.

5.6.3.3 Deriving the Neighbour Cell list from the GSM Neighbour Cell list and the 3G Neighbour Cell list

The Neighbour Cell list may contain up to 96 Neighbour Cells. For report with the PACKET ENHANCED MEASUREMENT REPORT message, the Neighbour Cell list is the concatenation of the GSM Neighbour Cell list and the 3G Neighbour Cell list (if any). In this concatenation the value of the parameter Absolute_Index_Start_EMR is added to the 3G Neighbour Cell list indices. If the same index occurs for a GSM Cell and a 3G Cell, the GSM Cell shall be used.

NOTE: For report with the PACKET MEASUREMENT REPORT message, the concatenated list is not used. Instead, the two lists are used separately, as defined in Table 11.2.9.2, "PACKET MEASUREMENT REPORT information element details" from sub-clause 11.2.9, "Packet Measurement Report".

5.6.3.4 GPRS Real Time Differences

The GPRS Real Time Difference list may contain up to 96 Real Time Difference parameters.

In a cell without PBCCH allocated, GPRS Real Time Difference information may be received from the SI2quater message and associated with the BA (list) from the SI2/SI2bis/SI2ter messages with the same BA_IND value, see 3GPP TS 04.18 (sub-clause 10.5.2.33b "SI 2quater Rest Octets"). Each frequency in the BA (list) may be associated to 0, 1 or more Real Time Difference parameters. The Real Time Difference parameters may be received before the corresponding BA (list). The parameter BA_Index_Start_RTD in each structure indicates the index of the frequency in the BA (list) to be taken as a starting reference. A sub-structure is included for each frequency referenced. Each of those sub-structures indicates if 0, 1 or more RTD parameters are present for this frequency. If a frequency in the BA (list) is not provided with Real Time Difference information by any of the message instances with correct BA_IND value, it shall be assumed that no information is available for that frequency. If the MP_CHANGE_MARK parameter is changed, the mobile station shall re-read the Real Time Difference parameters.

In a cell with a PBCCH allocated, GPRS Real Time Difference information may be received from the PSI3ter messages and associated with the GSM Neighbour Cell list with the same PSI3_CHANGE_MARK value. In this case each cell may be associated to 0 or 1 Real Time Difference parameter. The Real Time Difference parameters may be received before the corresponding GSM Neighbour Cell list. The parameter Cell_Index_Start_RTD in each structure indicates the index of the cell in the GSM Neighbour Cell list to be taken as a starting reference. A sub-structure is included for each GSM Neighbour Cell referenced. Each of those sub-structures indicate if 0 or 1 RTD parameter is present for this GSM Neighbour Cell. If a cell in the GSM Neighbour Cell list is not provided with Real Time Difference information by any of the message instances with correct PSI3_CHANGE_MARK value, it shall be assumed that no information is available for that cell. If some Real Time Difference information are provided for a cell that does not exist, this shall not be considered as an error. See sub-clause 11.2.21 ("Packet System Information Type 3bis").

5.6.3.5 GPRS Report Priority Descriptions

The GPRS Report Priority information is associated to the Neighbour Cell list and may be received before the corresponding Neighbour Cell list. Each REP_PRIORITY bit of this field relates to indices of the Neighbour cell list, starting with index 0.

Indices exceeding the value 95 shall be ignored. If there are fewer indices than the number of Neighbour Cells, the value 0 shall be assumed for the missing bits.

In a cell without PBCCH allocated, Report Priority information may be received from the SI2quater message and associated to the Neighbour Cell list with the same BA_IND value and 3G_BA_IND value, see 3GPP TS 04.18 sub-clause 10.5.2.33b ("SI 2quater Rest Octets"). If the parameter MP_CHANGE_MARK is changed, the mobile shall re-read the GPRS Report Priority information.

In a cell with a PBCCH allocated, Report Priority information for GSM cells may be received from the PSI3ter message and associated to the GSM Neighbour Cell list with the same PSI3_CHANGE_MARK value, see sub-clause 11.2.21a.

In a cell with a PBCCH allocated, Report Priority information for 3G cells may be received from the PSI3quater message and associated to the 3G Neighbour Cell list with the same PSI3_CHANGE_MARK value, see sub-clause 11.2.21b.

5.6.3.6 GPRS Measurement Parameters and GPRS 3G Measurement Parameters

In a cell without a PBCCH allocated, GPRS Measurement Parameters and GPRS 3G Measurement Parameters may be received from SI2quater message, see 3GPP TS 04.18 sub-clause 10.5.2.33b ("SI 2quater Rest Octets"). When the parameter MP_CHANGE_MARK is changed, the mobile station shall re-read GPRS Measurement Parameters and GPRS 3G Measurement Parameters.

In a cell with a PBCCH allocated, GPRS Measurement Parameters and GPRS 3G Measurement Parameters may be received from PSI3quater and PSI5 messages, see sub-clause 11.2.21b ("Packet System Information Type 3quater") and 11.2.23 ("Packet System Information Type 5"). When the PSI3_CHANGE_MARK or PSI5_CHANGE_MARK parameter is changed, the MS shall re-read the corresponding Measurement Parameters and 3G Measurement Parameters.

If different values are received for the same parameter in different instances of a message, only the value in the instance with the highest index shall be used.

5.6.3.7 The GPRS 3G Cell Reselection list

This applies only to a (3G) multi-RAT MS.

In a cell without a PBCCH allocated, the GPRS 3G Cell Reselection list is equal to the 3G Cell Reselection list that is defined in 3GPP TS 04.18.

In a cell with a PBCCH allocated, the GPRS 3G Cell Reselection list is the union of 3G Cells and/or 3G frequencies provided in one or more instances of the PSI3quater message. The GPRS 3G Cell Reselection list may contain up to 96 3G Cells. 3G Cells not provided explicitly in the PSI3quater message (frequencies on their own) are not included in these 96 cells. Up to 8 frequencies on their own can be added to these 96 cells.

The MS behaviour is not specified if the number of 3G frequencies or cells exceeds the MS monitoring capabilities as defined in 3GPP TS 05.08.