Topics

Nemo Events and DefinitionRRC and Layer3 messagesSIB Information,Measument Control (MC),Measurement Report (MR)CS and PS Call FlowCell Reselection, SHO and ISHO

Nemo Events and Definitions

Nemo Events and Definitions

MOCMTCMOC/MTC Call Flow timing

Nemo Events and Definitions

Block error ratio:BLER is measured from the CRC Transport Block (TB) is a basic unit that is exchanged between Layer 1 and Layer 2 (MAC). Layer 1 adds CRC for each TB and BLER is calculated from the CRC

Cell update causes in priority order:Uplink data transmissioninURA_PCH, CELL_PACHPaging responseinURA_PCH, CELL_PACHRadio link failureinCELL_DCH (*)Re-entering service areainCELL_FACH, CELL_PCHRLC unrecoverable errorinall sub-statesCell reselectionin CELL_FACH, CELL_PCHPeriodical cell updateinCELL_FACH, CELL_PCHURA update causes in priority order: (the UE is in the URA_PCH sub-state)URA reselectionPeriodic URA updateWhen do I have to perform a cell/ URA update?

RRC and Layer-3 MessagesSystem Information Blocks (SIB)

RRC Modes

DCCH and if configured DTCHDedicate physical channel in useUE location known on active set cell levelUE responsible for measurement reportingCell system information on BCCHRRC messages on DCCHDCCH and if configured DTCHFACH used for higher layer data transfer, UE monitors FACH permanentlyUplink transmission on RACHUE location known on serving cell levelUE performs cell re-selectionUE responsible for measurement reportingCell system information on BCCHRRC messages on BCCH, CCCH and DCCHno DCCH and DTCHBefore uplink transmission UE moves to CELL_FACHUE must be pagedRRC messages on BCCH and PCCHIn CELL_PCH - UE location known on cell level - UE performs cell re-selection and cell updatesIn CELL URA - UE location known on URA level - UE performs cell re-selection and URA updatesCELL_PCH and URA_PCHCELL_FACHCELL_DCH

What are the characteristics of the individual sub-states, when the UE is in the RRC connected mode?CELL_DCH In this sub-state, dedicated physical channels are allocated to the UE. DCCH and if configured DTCH information can be transmitted. There no need to identify the UE on a dedicated channel, because the physical channels are exclusively allocated to this UE. UTRAN knows the active set cells for the radio links and thus the location of the the UE. Also downlink shared channels can be allocated to the UE. In this state, the UE is capable to receive RRC messages on the DCCH (and BCCH, if it owns specific capabilities). The cell system information is broadcasted on the FACH. The UE reads the cell system information and acts accordingly. For instance, it determines the measurement quality and the reporting events from the cell system information. CELL_FACH This state was introduced for traffic situations, where only small amounts of data have to be transmitted. This is the case when only higher layer signalling information (NAS signalling) or small amount of user data (e.g. SMS messages) have to be transmitted. In this case, an exclusive allocation of one physical channel to the UE would result in a waste of resources. The UE is capable to receive and transmit DCCH and if configured DTCH information. Only common transport channel FACH can be used by the UE to transmit higher layer data, which it has to share with other UEs. Each UE must be explicitly addressed, for instance by the RNTI. It has to monitor the FACH permanently in the downlink, not to miss user data for it. The UEs FACH is mapped on one S-CCPCH. In the uplink, it uses the shared transport channels for user data transfer, such as the RACH. The UE is only connected to one cell, and this is the location information, known within UTRAN. No soft handover takes place in this sub-state. The UE is responsible for cell re-selection. By listening to the cell system information from the BCCH, it gains all relevant measurement qualities, threshold values, neighbourhood lists to perform the cell re-selection process. Other relevant information is also learned from the BCCH. The UE receives RRC messages on the BCCH, CCCH and DCCH channels. Due to the discontinuous type of traffic, UTRAN can command the UE to perform periodic cell updates.CELL_PCH In this sub-state, the UEs current cell is known to the RNC. If the RNC wants to exchange data with the UE, it only needs to page the UE there. If the UE changes the cell, it must perform a cell update. Also periodical cell updates can be requested by UTRAN. To perform updates, the UE must change to the CELL_FACH sub-state. (Please note, that no uplink transmission is allowed in CELL_PCH/URA_PCH.)

URA_PCH URA stands for UTRAN Registration Area. If the UE is in the CELL_PCH and moving fast, a lot of cell updates have to be performed. URAs are a combination of one or several cells under one C-RNC. URAs may overlap, i.e. a cell may belong to several URAs. If UTRAN wants to transmit something to the UE, it must page the UE within the URA. The UE is responsible for URA updates when it changes the URA and periodic URA updates when required by UTRAN.

States of Bearer Allocation

System InformationWithin UTRAN system information is broadcasted with the help of the RRC messagesSystem Information,Paging Type I, andSystem Information Change Indication.

Most system information parameters are determined by the RNC. The Node B is informed about the parameters via the NBAP message BCCH Information. Some system parameters can be made available by the Node B, such as interference values, which change fast. Given the system information, the UE is capable to decide, whether or how to access the PLMN via the existing cell.

System information is organised in System Information Blocks (SIBs). System information is grouped into SIB 1 to SIB 18. Each SIB is responsible to carry a specific content. For instance, SIB 12 holds measurement control information and parameters. Depending on the UEs RRC state, it reads specific SIBs, and uses the transmitted parameters.

There is a huge amount of SIBs, which have to be read by the UE. This requires a lot of battery power.

Therefore, a Master Information Block (MIB) was introduced, which gives references and scheduling information about the SIBs. The MIB is transmitted in every 8th radio frame on the P-CCPCH (on position SFN mod 8 = 0, and with a TTI of 20 ms). For most of the SIBs used within the system, the MIB may carry a value tag. The only exceptions are SIB 15.2, SIB 15.3 and SIB 16. If a value tag is unchanged, the corresponding system information has not been modified. Thus, there is no need for the UE to read the SIB. SIB 7 has no value tag. It changes with each occurrence. Scheduling information is used to inform the UE, where and when a specific system information is transmitted.

NBAP = Node B Application Part

UTRAN can notify UEs, that a value tag in the MIB has been changed. Hereby, the information element BCCH Modification Info is broadcasted. There are two RRC messages, which can carry this information element: Paging Type 1 Some mobile phones have no radio link allocated, mobile phones, which are in the RRC idle mode, and in the RRC connected mode sub-states CELL_PCH and URA_PCH. This paging message is transmitted in all paging occasions in the cell. System Information Change Indication With this message, we address UEs in the CELL_FACH sub-state. Consequently, this message must be transmitted on every S-CCPCH, which carries FACHs. The System Information Change Indication message is transmitted on a BCCH, which must be mapped on FACHs in such a way, that every S-CCPCH carries the BCCH Modification Change IE.

Within the IE BCCH Modification Change, even a BCCH Modification Time can be given, indicating to the UEs, when the value tags will change.

Please note, that UEs in the CELL_DCH sub-state are addressed directly by the RNC via the Measurement Control message.

In this course documentation, we only describe the System Information Blocks (SIBs), which are used in Nokias RAN1, and SIB 4 and SIB16. Please note, that all SIBs are valid on cell level except for SIB 1, SIB 15.3, and SIB 16. SIB 1 and SIB 15.3 are valid on PLMN level, while SIB 16 is valid for equivalent PLMNs.

For each SIB, following characteristics were specified:Area scope: Where is the value tag valid: within one cell or within a PLMN/ equivalent PLMN?UE RRC state: When the SIB is valid?UE RRC state: When the SIB is read?Scheduling information: At which position is the SIB transmitted and what is its repetition period?Modification of system information: Is it indicated by a value tag, or is it timer based?

The UE receives all SIBs via the BCCH. There is only one exception: SIB 10. If a UE is capable to receive simultaneously one S-CCPCH and one DPCH, than it receives SIB 10 on a FACH.

Master Information Block (MIB): The MIB informs the UE about the supported PLMN types and the PLMN identity. The UE finds in the MIB also references to up to maxSIB (=32) SIBs, including their scheduling information and type. A MIB is valid in one cell. If a UE changes the cell, is must read the new cells MIB. The MIB is read in the RRC modes/states RRC idle, CELL_FACH, CELL_PCH and URA PCH. Its parameter are valid in the same states. A change of the MIB information is indicated by a value tag. In this course documentation, we only describe the System Information Blocks (SIBs), which are used in Nokias RAN1, and SIB 4 and SIB16. Please note, that all SIBs are valid on cell level except for SIB 1, SIB 15.3, and SIB 16. SIB 1 and SIB 15.3 are valid on PLMN level, while SIB 16 is valid for equivalent PLMNs.

SIB1System Information Block 1 (SIB 1) This SIB is used to inform the UE about NAS system information. The NAS system information characterises the NAS domains. SIB 1 also delivers UE timers and counters, which have to be used by the UE in the RRC idle and RRC connected mode. For instance, a UE in the RRC connected mode uses the timer T305 for periodic cell and URA updates. SIB 1 is valid in one PLMN. The MIB is read in the RRC modes/states RRC idle, CELL_FACH, CELL_PCH and URA PCH. Its parameter are valid in the same states, and the the RRC sub-state CELL_DCH. If the UE selects a new cell, and the SIB 1 value tag has the same number as in the preceding cell, the same content is transmitted in this SIB. There is then no necessity for the UE to read this SIB after cell re-selection.T302/N302 The CELL UPDATE/URA UPDATE retransmission timer (MS timer)

T300/N300 The RRC CONNECTION REQUEST retransmission timer (MS timer)

T312/N312 The timer for supervising successful establishment of aphysical channel (MS timer)

T309 The timer for supervising successful connection establishment in case of an inter-RAT cell re-selection (MS timer)

T316 This timer is started when the UE detects an out of service area in URA_PCH or CELL_PCH state. This timer is stopped when the UE detects an in service area. When the timer expires the UE initiates cell update procedure (MS timer).

T317 This timer is started when the T316 expires and the UE detects an out of service area. This timer is stopped when the UE detects an in service area. When the timer expires the UE transits to idle mode (MS timer)

SIB2System Information Block 2 (SIB 2) This SIB contains an URA identity list. SIB 2 is read and valid in the RRC sub-state URA_PCH. A change of the SIB 2 information is indicated by a value tag.

SIB3System Information Block 3 (SIB 3) This SIB contains relevant parameters for cell selection and re-selection. It also holds the cell identity and cell restriction data, such as cell barred IEs. SIB 3 must be read and is valid in the RRC idle mode. It is read and valid in the RRC connected mode sub-states CELL_FACH, CELL_PCH and URA_PCH, if SIB 4 is not broadcasted. A change of the SIB 3 information is indicated by a value tag.

SIB5System Information Block 5 (SIB 5) The parameters for the configuration of physical channels are broadcasted in this SIB. The parameters cover the PICH power offset, the AICH power offset, P-CCPCH, S-CCPCH and PRACH system information lists. SIB 5 must be read and is valid in the RRC idle mode. It is read and valid in the RRC connected mode sub-states CELL_FACH, CELL_PCH and URA_PCH, if SIB 6 is not available. A change of the SIB 5 information is indicated by a value tag.

SIB7System Information Block 7 (SIB 7) This SIB holds fast changing parameters. Therefore no value tag is used for it. The UE has to read its parameters periodically. For that, an expiration timer (Expiration Time Factor) is broadcasted with this message. SIB 7 expires at max(32, 8 * Expiration Time Factor). Expiration Time Factor can have the values 2times, 4 times, 8 times ... 256 times. Its default value is 1. The fast changing parameters transmitted with SIB 7 include the UL interference and dynamic persistence level. It is read and valid in all states except for the CELL_DCH sub-state.

SIB11System Information Block 11 (SIB 11) This SIB holds measurement control information. The UE gets here the relevant date for traffic measurement, intra-frequency measurements, etc. SIB 11 must be read and is valid in the RRC idle mode. It is read and valid in the RRC connected mode sub-states CELL_FACH, CELL_PCH and URA_PCH, if SIB 12 is not broadcasted. It is also valid in the RRC sub-state CELL_DCH, as long as the UE did not get a Measurement Control message from UTRAN and SIB 12 is not broadcasted. A change of the SIB 11 information is indicated by a value tag.

SIB11

SIB11

SIB12System Information Block 12 (SIB 12) SIB 12 transmits measurement control information for UEs in the RRC connected mode. If not transmitted, the UEs take the parameters broadcasted with SIB 11. If available, SIB 12 is read and valid in the RRC connected mode sub-states CELL_FACH, CELL_PCH and URA_PCH. It is also valid in the RRC sub-state CELL_DCH, as long as the UE did not get a Measurement Control message from UTRAN. A change of the SIB 12 information is indicated by a value tag. System Information Block 16 (SIB 16) RB, TrCH, and PhyCH parameters are broadcasted, which are stored by the UE both in the RRC idle and RRC connected mode. The parameters are used during a handover to UTRAN. Consequently, these parameters stay valid, when the UE is connected to GSM and GPRS. This SIB is valid in all RRC states, and read in all RRC states except for the CELL_DCH. The UE reads and stores the parameters. A change of the SIB 16 information is indicated by a value tag. SIB16

RRC messages information - PS

Modify max bit rate by Nemo

Measurement Control (MC) and Measurement Report (MR)UTRAN controls the measurements in the UE, either bybroadcasting system information on the BCCH, and/or bytransmitting a Measurement Control message on the DCCH.

If the UE is in the RRC idle mode, it receives relevant measurement information from the BCCH. The SIB type 3 contains parameters for cell selection and re-selection. In parallel, the SIB type 11 is used to deliver measurement control information to the UE for the serving cell. SIB 3 and SIB 11are read and valid in the RRC idle state. If the UE is in the RRC sub-states CELL_FACH, CELL_PCH and URA_PCH, it is connected to one cell only and responsible for cell selection and re-selection. It retrieves the parameters for cell selection from SIB type 4. The measurement control information is broadcasted with SIB type 12. SIB 4 and SIB 12 are read and valid, when the UE is in the CELL_FACH, CELL_PCH and URA_PCH sub-state. If SIB 4 resp. SIB 12 is not broadcasted, then SIB 3 resp. SIB 11 parameters are used instead. In the sub-state CELL_DCH, the UE is not reading the SIB type 3/4 and 11/12. The parameters of SIB 12 (SIB 11, if SIB is not available) can be still valid in this state.

The RRC message Measurement Control can be transmitted to the UE, if a DCCH has been setup between the UE and UTRAN. This message informs the UE about the type of measurement, which has to be conducted. Each measurement command links a measurement with a measurement identity, quantity, objects, reporting quantities, reporting criteria, type, etc.

Measurement Control (MC) and Measurement Report (MR)How does a UE perform measurements after a transition in the CELL_DCH state. Two cases have to be distinguished:

Transition from the RRC idle state to the CELL_DCH sub-state In the RRC idle state, the UE retrieved the measurement control parameters from the SIB type 11. Information Elements, which contain intra-frequency, inter-frequency, inter-RAT and traffic volume measurement system information, may be included in the SIB 11. If they are included, the UE can send a measurement report, when a measurement reporting criteria is fulfilled. As soon as the UE receives a Measurement Control message including one of the above mentioned measurement types, it replaces its internal stored data based on the SIB11 by the parameters delivered with the Measurement Control message.

Transition from the CELL_FACH to the CELL_DCH sub-state. In the CELL_FACH sub-state, the SIB 12 (or SIB 11, if there is no SIB 12) is valid including all relevant measurement control parameters. If the UE transits to the CELL_DCH sub-state, the system information stays valid, as long as there was no Measurement Control message, which replaces the parameters. But what happens, if the UE was in the CELL_DCH sub-state, it has received Measurement Control messages, and it then transits to the CELL_FACH sub-state. In the CELL_FACH sub-state, the UE reads SIB 12 (SIB 11), and its measurement control parameters become valid. But when the UE then transits back to the CELL_DCH sub-state, the UE resumes with the measurements and associated reporting, as they were stored before the transition to the CELL_FACH (or any other RRC connected) sub-state.

The RRC message Measurement Control is used to setup, to modify, and to release a measurement in the UE. The UE gets all relevant information, how to perform a specific type of measurements. A measurement is either conducted periodically or driven by an event. Then, the UE returns a measurement report. The Measurement Control message is transmitted on a DCCH via an RLC entity in the acknowledged mode. I.e. the UE is either in the RRC connected sub-state CELL_DCH or CELL_FACH. If the setup of a measurement fails, the UE returns the RRC message Measurement Control Failure. It is transmitted on an UL DCCH via an RLC entity in the acknowledged mode. The RRC message Measurement Report was specified to deliver measurement results from the UE to UTRAN (RNC). This message is transmitted on a DCCH. The RLC entity can be in the acknowledged or unacknowledged mode. The RLC entity mode is set by the RRC message Measurement Control.

Measurement results can be only transmitted in the CELL_DCH or CELL_FACH sub-state. CELL_DCH: If a reporting criterion is met, the UE transmits a Measurement Report. A measurement identity identifies the measurement as specified by UTRAN. It includes measurement quantities and identifies the measurement event.CELL_FACH: In this sub-state, traffic volume measurements and positioning measurements are reported by the UE. Intra-frequency measurements are reported via the RACH, whereby the UE learns from the BCCH (SIB11 or SIB12) the maximum numbers of cells, it can report. CELL_PCH or URA_PCH: UE must perform a cell update. Cell update cause is uplink data transmission. Then they are in the CELL_FACH state, where the Measurement Report can be sent. The measurement report either holds traffic volume measurements or positioning measurements.Measurement Control (MC) and Measurement Report (MR)

With the RRC message Measurement Control, UTRAN commands the UE to perform measurements on its behalf. There is a set of different types of measurements, which can be conducted:

Intra-Frequency MeasurementsInter-Frequency MeasurementsInter-RAT MeasurementsUE-Internal MeasurementsTraffic Volume MeasurementsQuality MeasurementsUE Positioning MethodsAs a consequence, a UE may be forced to conduct several different types of measurementssimultaneously. Each type of measurement is identified by an allocated Measurement Identity.

Some measurements are not conducted continuously. UTRAN tells the UE once, how to perform a type of measurements. Whenever necessary, it just informs the UE to conduct the measurements of a measurement type by just telling it the associated measurement identity.

Each measurement type comes with a measurement command: setup, modify, and release.

Finally, UTRAN inform the UE, how to deliver the measurement reports:Delivery on an acknowledged or unacknowledged RLC, andPeriodical or event triggered reporting.

In the RRC message Measurement Control, the is an PhyCH information elements, where the UE can gain DPCH compressed mode status information. Measurement Control (MC) and Measurement Report (MR)

Traffic Volume MeasurementsTraffic volume measurements are used to trigger measurement reports based on uplink traffic volume.

Why is it necessary to perform this type of measurement? The UE is in the RRC connected sub-state CELL_FACH. The volume of uplink traffic is increasing. UTRAN tells the UE to report an increased amount of uplink traffic. UTRAN (here: the S-RNC) can decide to allocate dedicated physical channel resources to the UE. In other words, the UE is moved to the CELL_DCH sub-state. The measurement object is the individual cell. The reported quantities are Buffer Occupancy (BO) which indicates for each logical channel the amount of data in number of bytes that is available for transmission and retransmission in the RLC layer. (TS 25.321) At least every TTI, the MAC layer receives this information from each RLC entity. Average of Buffer OccupancyVariance of Buffer Occupancy.

The two last reporting quantities are statistics, which the MAC layer computes and delivers after being configured accordingly by the RRC. These statistics on BO values are determined from all RBs/LogCHs mapped onto a given TrCH. The Transport Channel Traffic Volume (TCTV) is the sum of the BO of all LogCHs, mapped on a given TrCH. The evaluation has to be done at least once every TTI.

Following reporting events were specified: 4A: Transport Channel Traffic Volume becomes larger than an absolute threshold4B: Transport Channel Traffic Volume becomes smaller than an absolute threshold

Traffic Volume Measurements

RRC messages informationUL Traffic volumes High threshold information sent after RAB setup complete (CELL_DCH)

RRC messages informationUE Buffer triggers Threshold for RAB Upgrade

RRC messages informationFirst RAB ReconfigurationDL 32Kbps(SF64)/ UL 32Kbps SF32)

RRC messages informationUL Traffic volumes High threshold information sent after RAB setup complete (CELL_DCH)

RRC messages informationMaximum DL bit rate for PS domain NRT data = 384 KbpsMaximum UL bit rate for PS domain NRT data = 64 KbpsInitial and minimum allowed bit rate in downlink = 32 KbpsInitial and minimum allowed bit rate in uplink = 32 Kbps

RRC messages informationCell DCH Cell FACH

RRC messages informationCell FACH Cell PCH

RRC messages informationCell PCH Cell FACH

RRC messages informationCell FACH Cell DCH

Quality Reporting Event How good is the connection? Downlink, this must be determined by the UE, uplink by the Node B. Downlink, the quality measurements are used to set DL quality thresholds, such as the DL TB error rate.

In contrast to the UE internal measurements, there is only one specified reporting event:5A: A predefined number of bad CRCs is exceeded (when a DCH is established) If the reporting of 5A is ordered by UTRAN, the UE sends a report to indicate to UTRAN, that the number of bad CRCs during a predefined sliding window has exceeded a predefined number. The following three parameters are used: - Total CRC is the length of the sliding window over which the number of bad CRCs are counted. - Bad CRC tells the UE the number of bad CRCs that are required within "Total CRC" for the event to be triggered. - Pending after trigger is a time period. A new event can not be triggered until "Pending after trigger" CRCs have been received.

The Quality Deterioration report is used when the UL outer loop power control is not reaching it's BLER/BER target. If the DL link quality is not reaching its quality target, the RNC can increase the SIR set at the Node B to improve the link quality. But this reduces also the capacity of the serving cells and increases the interference level, imposed on the radio links of other Ues served in the same geographical area. The Radio link measurements from BTS are used to check whether the DL DPCH power of the radio link is approaching it maximum value. If such a situation is given, this may trigger measurements in the compressed mode (handover measurements).

Quality Reporting Event

Cells for Measurement and Monitoring (new)The mobile phone is capable to run several measurement types in parallel. Each measurement is hereby controlled and reported independently. The UE groups the monitored cells: Active Set Cells The UE is connected to all these cells, performing a soft handover. User data can be transmitted in all these cells. For measurements and event reporting, the UE only considers cells, which are stored in the CELL_INFO_LIST for measurements. If an active cell set is not stored there, the UE wont consider it for event evaluation and measurement reporting. Monitored Set Cells The cells, which are stored in the CELL_INFO_LIST are monitored set cells, when they are not active set cells. Detected Set Cells The UE is capable to detect cells, which do not belong to the two above mentioned sets. They are stored in the detected set list. Measurement reporting of detected set cells can be conducted only for intra-frequency measurements, when the UE is in the CELL_DCH sub-state

In the RRC message, the IE Cells for measurements can be included. If so, only these cells are considered for the (intra-, inter-, or inter-RAT) measurement. If the IE Cells for measurements is not included in the RRC message, than all cells must be considered for measurements, which are stored in the CELL_INFO_LIST.

Intra-frequency measurements are measurements on downlink physical channels at the same frequency as the active set. The measurement object is one cell.If the RRC message Measurement Control commands the UE to make intra-frequency measurement, it may contain among others:Intra-frequency cell info list (optional)Measurement quantity There are three different measurement quantities for the FDD mode: - Downlink Ec/N0 - Downlink received signal code power (RSCP) after despreading. - Downlink pathloss in dB = Primary CPICH Tx power - CPICH RSCP.Measurement validity The measurement validity describes, when the measurement has to be conducted. There are three options: - CELL_DCH state, - all states except the CELL_DCH state, and - all states. Reporting Criteria Reporting criteria outline, what kind of intra-frequency measurements have to be conducted. A set of intra-frequency measurements were specified, but it is the operators choice, which ones are used.Intra-frequency Measurements

Below, you can see a list of intra-frequency reporting events. UTRAN decides, which of the listed events have to be reported by the UE. The required intra-frequency reporting events, which are choosen by UTRAN, depend on the implemented handover reporting function or other radio network functions. The measurement quantities are determined by measuring the P-CPICH of the cell.

Reporting events1A: A Primary CPICH enters the reporting range The reporting range can be between 0 and 14.5 dB (step size 0.5 dB). The reporting range can be set in relation with the measurement of the best (strongest) cell as is was displayed on the next figure. It can be also set in ration with a weighted average of the best measured cell and the averaged measurement results of additional, non-forbidden cells. If a CPICH crosses the reporting range, a reporting event is triggered. A individual cell offset can be taken into account. 1B: A primary CPICH leaves the reporting rang Similar concept as in 1A.1C: A non-active primary CPICH becomes better than an active primary CPICH1D: Change of best cell1E: A Primary CPICH becomes better than an absolute threshold (RAN 1.5)1F: A Primary CPICH becomes worse than an absolute threshold (RAN 1.5)

A hysteresis value can be set before reporting the event in all reporting events in the figures, this is only shown for 1A and 1B. Intra-frequency Reporting EventsInter-rat

Intra-frequency Reporting Events

Intra-frequency Reporting Events

1E for cell 3Intra-frequency Reporting Events

Neighbourhood ListsIn the RRC idle state and in the RRC connected sub-states CELL_FACH, CELL_PCH and URA_PCH, the UE is responsible for cell selection and re-selection. It camps on one cell or it is served by one cell. By reading the System Information Block 11 and/or 12, the UE gets the Intra-frequency cell info list,Inter-frequency cell info list, andInter-RAT cell info list,i.e. it gets several neighbourhood lists.

In the CELL_DCH sub-state, the RNC must be able to continuously update the neighbour cell lists in order to reflect the changing neighbourhood of a moving mobile station. This is part of the RNCs handover control. If we have more than one active set cell, which participate in a soft handover, the handover control of the RNC is responsible to combine the lists into one neighbour cell list which is then transmitted to the mobile station. The neighbour cell list combination is carried out in the steps depicted in next slide. A soft handover only takes place with cells on the same UTRA carrier band. Consequently, the combining of neighbourhood lists of several active set cells is only required for intra-frequency handovers and has to combined with their measurements.

Neighbourhood List Combination for Intra-frequency HOsTwo Cells in the Active Set

Neighbourhood List Combination for Intra-frequency HOsThe neighbourhood lists for intra-frequency handover measurements can be composed like this:

Step 1: Active set cells First the handover control sets the active set cells into the neighbour cell list.

Step 2: Neighbour cells which are common to three active set cells During the second step of neighbour cell list combination the handover control selects those neighbour cells which are common to all three active set cells. If the total number of relevant neighbour cells exceeds the maximum number of 32 after the second step, the handover control removes in random order those surplus cells from the combined neighbour cell list which are selected during the second step

Step 3: Neighbour cells which are common to two active set cells During the third step of neighbour cell list combination the handover control selects those neighbour cells which are common to two active set cells. If the total number of relevant neighbour cells exceeds the maximum number of 32 after the third step, the handover control removes in random order those surplus cells from the combined neighbour cell list which are selected during the third step.

Step 4: Neighbour cells which are defined for only one active set cell During the fourth step of neighbour cell list combination the handover control selects those neighbour cells which are defined for only one active set cell. If the total number of relevant neighbour cells exceeds the maximum number of 32 after the fourth step, the handover control removes those surplus neighbours from the combined neighbour cell list which are selected during the fourth step, starting from the neighbours of the weakest (CPICH Ec/Io) active set cell.

Neighbourhood List Combination for Intra-frequency HOsCell2Cell 7Cell 9Cell 11Cell 15Cell 10Cell 37Cell 41Cell 49..Cell 22

CS and PS Call FlowWhen a UE is switched on, it starts to monitor the radio interface to find a suitable cell to camp on. But it has to determine, whether there is a WCDMA cell nearby. If a WCDMA cell is available, the UE has to be synchronised to the downlink transmission of the system information transmitted on the physical channel P-CCPCH before it can make a decision, in how far the available cell is suitable to camp on. Initial cell selection is not the only reason, why a UE wants to perform cell synchronisation. This process is also required for cell re-selection and the handover procedure.

Cell synchronisation is achieved with the Synchronisation Channel (SCH). This channel divides up into two sub-channels: P-SCH and S-SCH

With the help of the SCH, the UE was capable to perform chip, TS, and frame synchronisation. Even the cells scrambling code group is known to the UE.

The UE knows the cells primary scrambling code. It now wants to gain the cell system information, which is transmitted on the physical channel P-CCPCH. The channelisation code of the P-CCPCH is also known to the UE, because it must be Cch,256,1 in every cell for every operator. By reading the cell system information on the P-CCPCH, the UE learns everything about the configuration of the remaining common physical channels in the cell, such as the physical channels for paging and random access.

Cell SearchRAB 1st then RRC

UERNCNodeBMGW/CNRRC: RRC Connection Request (RACH)NBAP: Radio Link Setup RequestNBAP: Radio Link Setup ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RRC: RRC Connection Setup (FACH) [RRCconnRepTimer1/2(100ms,1s)]L1 SynchronizationNBAP: Synchronization IndicationRRC: RRC Connection Setup Complete (DCH)RRC: Initial Direct Transfer (MM: CM Service Request)SCCP: CR (Connection Request)RANAP: Initial UE Message (MM: CM Service Request)SCCP: CC (Connection Confirm)RANAP: Direct Transfer (MM: Authentication Request)RRC: Downlink Direct Transfer (MM: Authentication Request)RRC: Uplink Direct Transfer (MM: Authentication Response)RANAP: Direct Transfer (MM: Authentication Response)RANAP: Common IDRANAP: Security Mode CommandRRC: Security Mode CommandFP: Downlink SynchFP: Uplink SynchRRC Connection Establishment CELL DCH StateRNC checks if resources are available: BTS, AC, Transmission.If not it sends RRC Connection RejectT300=2s ; N300=3L1 SynchronizationT312=6s ; N312=4MOS CS Message FlowRRC Connection till the RNC

UERNCNodeBMGW/CNRRC: Security Mode CompleteRANAP: Security Mode CompleteRRC: Uplink Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Call Confirmed)RRC: Downlink Direct Transfer (CC: Call Confirmed)RANAP: RAB Assignment RequestNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)NBAP: Radio Link Reconfiguration Commit)RRC: Radio Bearer SetupRRC: Radio Bearer Setup CompleteRANAP: RAB Assignment ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RAB EstablishmentFP: Downlink SynchFP: Uplink SynchRL modification procedure:SRB+DCH, HW resources checkedPossible failure in AAL2 setup (Iub, Iur and Iu)Soft handover is not allowed during the RAB establishment procedure (The mobile can not add or remove cells in AS) this makes the UE and Node B particularly sensitive to mobility and dominance Timer wf_rb_setup_cpl (6s) is started when the RRC: Radio Bearer Setup message is sent to the UE In case the timer expires Iu Release Request is sent to the CN with release cause (radio_conn_lost)

Call EstablishedUERNCNodeBRANAP: Direct Transfer (CC: Connect)RRC: Downlink Direct Transfer (CC: Connect)RRC: Uplink Direct Transfer (CC: Connect Acknowledge)RANAP: Direct Transfer (CC: Connect Acknowledge)RRC: Uplink Direct Transfer (CC: RRC Connection Release Complete)RANAP: Direct Transfer (CC: Release Complete)RANAP: Iu Release CommandRRC: Uplink Direct Transfer (CC: Disconnect)RANAP: Direct Transfer (CC: Disconnect)RANAP: Direct Transfer (CC: Release)RRC: Downlink Direct Transfer (CC: Release)RANAP: Iu Release CompleteMGW/CNRANAP: Location ReportRRC: Measurement ControlCall DisconnectRRC: Downlink Direct Transfer (CC: RRC Connection Release)RRC: Uplink Direct Transfer (CC: RRC Connection Release Complete)RRC: Uplink Direct Transfer (CC: RRC Connection Release Complete)NBAP: Radio Link Deletion RequestNBAP: Radio Link Deletion ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RANAP: Direct Transfer (CC: Alerting)RRC: Downlink Direct Transfer (CC: Alerting)

UERNCNodeBMGW/CNRRC: RRC Connection Request (RACH)NBAP: Radio Link Setup RequestNBAP: Radio Link Setup ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RRC: RRC Connection Setup (FACH)L1 SynchronizationNBAP: Synchronization IndicationRRC: RRC Connection Setup Complete (DCH)RRC: Initial Direct Transfer (MM: Paging Response)SCCP: CR (Connection Request)RANAP: Initial UE Message (MM: Paging Response)SCCP: CC (Connection Confirm)RANAP: Direct Transfer (MM: Authentication Request)RRC: Downlink Direct Transfer (MM: Authentication Request)RRC: Uplink Direct Transfer (MM: Authentication Response)RANAP: Direct Transfer (MM: Authentication Response)RANAP: Common IDRANAP: Security Mode CommandRRC: Security Mode CommandFP: Downlink SynchFP: Uplink SynchRRC Connection Establishment CELL DCH StateL1 SynchronizationMTC CS Message FlowRANAP: PagingRRC: Paging Type 1

UERNCNodeBMGW/CNRRC: Security Mode CompleteRANAP: Security Mode CompleteRRC: Uplink Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Call Confirmed)RRC: Downlink Direct Transfer (CC: Call Confirmed)RANAP: RAB Assignment RequestNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)NBAP: Radio Link Reconfiguration Commit)RRC: Radio Bearer SetupRRC: Radio Bearer Setup CompleteRANAP: RAB Assignment ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RAB EstablishmentFP: Downlink SynchFP: Uplink SynchRL modification procedure:SRB+DCH, HW resources checkedPossible failure in AAL2 setup (Iub, Iur and Iu)Soft handover is not allowed during the RAB establishment procedure (The mobile can not add or remove cells in AS) this makes the UE and Node B particularly sensitive to mobility and dominance Timer wf_rb_setup_cpl (6s) is started when the RRC: Radio Bearer Setup message is sent to the UE In case the timer expires Iu Release Request is sent to the CN with release cause (radio_conn_lost)

Call EstablishedUERNCNodeBRANAP: Direct Transfer (CC: Connect)RRC: Downlink Direct Transfer (CC: Connect)RRC: Uplink Direct Transfer (CC: Connect Acknowledge)RANAP: Direct Transfer (CC: Connect Acknowledge)MGW/CNRANAP: Location ReportRRC: Measurement ControlRANAP: Direct Transfer (CC: Alerting)RRC: Downlink Direct Transfer (CC: Alerting)

UENodeBRNCSGSNNBAP: Radio Link Setup RequestNBAP: Radio Link Setup ResponseAAL2SIG: ERQAAL2SIG: ECFNBAP: Synchronization IndicationRRC: Initial Direct Transfer (MM: Attach Request)RANAP: Initial UE Message MM: (Attach Request)RANAP: Direct Transfer (MM: GPRS Identity Request)RRC: Downlink Direct Transfer (MM: GPRS Identity Request)RRC: Uplink Direct Transfer (MM: GPRS Identity Response)RANAP: Direct Transfer (MM: GPRS Identity Response)RANAP: Direct Transfer (MM: Authentication & Ciphering Request)RRC: Downlink Direct Transfer (MM: Authentication & Ciphering Request)RRC: Uplink Direct Transfer (MM: Authentication & Ciphering Response)RANAP: Direct Transfer (MM: Authentication & Ciphering Response)RANAP: Security Mode CommandRRC: Security Mode CommandRRC: Security Mode CompleteRANAP: Security Mode CompleteRANAP: Common IDMOS PS Message FlowL1 SynchronizationRRC: RRC Connection Request (RACH)FP: Downlink SynchFP: Uplink SynchRRC: RRC Connection Setup Complete (DCH)RRC Connection Establishment CELL DCH StateRRC: RRC Connection Setup (FACH) [RRCconnRepTimer1/2(100ms,1s)]RNC checks if resources are available: BTS, AC, Transmission.If not it sends RRC Connection RejectL1 Synchronization

RANAP: Direct Transfer (MM: Attach Accept)RRC: Downlink Direct Transfer (MM: Attach Accept)RRC: Uplink Direct Transfer (MM: Attach Complete)RANAP: Direct Transfer (MM: Attach Complete)RRC: Uplink Direct Transfer (SM: Activate PDP Context Request)RANAP: Direct Transfer(SM: Activate PDP Context Request)UENodeBRNCSGSNMOS PS Message FlowNBAP: Radio Link Reconfiguration CommitRRC: Radio Bearer ReconfigurationRRC: Radio Bearer Reconfiguration CompleteNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyRRC: Radio Bearer SetupRRC: Radio Bearer Setup CompleteRANAP: RAB Assignment ResponseRANAP: Direct Transfer(SM: Activate PDP Context Accept)RRC: Downlink Direct Transfer (SM: Activate PDP Context Accept)RANAP: RAB Assignment RequestRRC: Measurement ControlRRC: Measurement Repor (Trafic Volume Reports 4a)AAL2SIG: ERQAAL2SIG: ECFRAB EstablishmentSRB + DCH 0/0RL modification procedure:SRB+DCH, HW resources checkedUplink & Downlink Data Transfer

RRC: Uplink Direct Transfer (SM: Deactivate PDP Context Request)RANAP: Direct Transfer (SM: DeactivatePDP Context Request)RANAP: Direct Transfer(SM: Deactivate PDP Context Accept)RRC: Downlink Direct Transfer (SM: Deactivate PDP Context Accept)NBAP: Radio Link Reconfiguration CommitNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyAAL2SIG: ERQAAL2SIG: ECFRRC: Radio Bearer ReleaseRRC: Uplink Direct Transfer (MM: Detach Request)RANAP: Direct Transfer (MM: Detach Request)RANAP: Direct Transfer (MM: Detach Accept)RRC: Downlink Direct Transfer (MM: Detach Accept)UENodeBRNCSGSNRANAP: Iu Release CommandRANAP: Iu Release CompleteRRC: Radio Bearer Release CompleteRRC: RRC Connection ReleaseRRC: RRC Connection Release CompleteNBAP: Radio Link Deletion RequestNBAP: Radio Link Deletion ResponseAAL2SIG: REL (Release Request)AAL2SIG: RCL (Release Confirm)RRC: RRC Connection Release CompleteRRC: RRC Connection Release CompleteMOS PS Message Flow

* 2006 Nokia 0 bit rateBased on e4a

* 2006 Nokia

Real traffic transferBearer setupRRC setup

9:52:53 : C09 AMR

Soft Handover

* 2006 Nokia Handover TypesIntra-Frequency HandoversSofter HandoverHandover between sectors of the same Node B (handled by BTS)No extra transmissions across Iub interfaceMaximum Ratio Combining (MRC) is occurring in both the UL and DLSoft HandoverMS simultaneously connected to multiple cells (from different Node Bs)Extra transmission across Iub, more channel cards are needed (compared to non-SHO)Mobile Evaluated Handover (MEHO)DL/UE: MRC & UL/RNC: Frame selection combiningHard HandoverArises when inter-RNC SHO is not possible (Iur not supported or Iur congestion)Decision procedure is the same as SHO (MEHO and RNC controlled)Causes temporary disconnection of the (RT) userInter-Frequency HandoverCan be intra-BS, intra-RNC, inter-RNC Network Evaluated Handover (NEHO)Decision algorithm located in RNCInter-RAT Handover Handovers between GSM and WCDMA (NEHO)

* 2006 Nokia

* 2006 Nokia Soft Handover Main method is soft/softer Handover MS connected to two or more cells Up to 3 branches can be used (MaxActiveSetSize parameter) Seamless Handover without any disconnection of UE-RAN connection softer Handover probability about 5-15 % : soft Handover probability about 20-50 %

Same power levels in use for all soft Handover branches Optimum power levels for link quality and cell capacity Macro Diversity Combining (MDC) gain to reduce power levels

Mobile Evaluated Handover (MEHO) Enables different cell sizes due to Common Pilot Channel Ec/No measurement Optimum fast close loop power control in use Outer loop PC after MDC controls the BLER according to set target and thus maintains the quality

* 2006 Nokia

SHO: Neighbour Cell DefinitionEach intra-frequency neighbour (ADJS) is identified using ADJSid (ADJS)The ADJS parameters provide information on the identity of each neighbour cell together with its properties (i.e. Handover parameter set identifier, scrambling code etc..)Each neighbour cell is defined using the UTRAN cell identifier which comprisesUTRAN Cell Identifier = MCC + MNC + RNC identifier + Cell identifier Each neighbor cell is defined using the UTRAN cell identifier which comprises; MCC(Mobile Country Code) = AdjsMCC MNC(Mobile Network Code) = AdjsMNC RNC Identifier = AdjsRNCid Cell Identifier = AdjsCI The LAC (AdjsLAC) & RAC (AdjsRAC) are also in ADJS parameter setADJS Parameters

* 2006 Nokia Neighbour Cell DefinitionSeparate Handover Parameter Set (HOPS) identifiers for real time(RT) & non-real time(NRT) traffic RtHopsIdentifier - real time NrtHopsIdentifier - non-real timeHSDPAHopsIdentifier - HSDPA Each HOPS object is identified by a unique HOPSid (HOPS) in the RNC - on to which the xxHopsIdentifier parameters are mapped to identify the appropriate HOPS parameter set for that particular neighbor cell

Primary scrambling code for neighbor cell specified using AdjsScrCode AdjsTxDiv specifies whether the neighbor cell is using Tx diversity AdjsTxPwrRACH determines the maximum power the UE can use on the PRACH when accessing the neighbor cell

* 2006 Nokia

* 2006 Nokia Maximum number of neighboursThe maximum number of neighbours that can be defined in RNC database isADJS: 3131 neighbours + serving cell = 32 cells to measureADJI: 32/carrier, total 48ADJG: 32

Total: max. 111 in RNC database

Limitation due to specifications of SIB11/12 size

* 2006 Nokia

* 2006 Nokia Maximum number of neighbours SIB11 length limitation3GPP has inconsistent requirements concerning the maximum number of neighbouring cells that can be broadcasted in the SIB 11 and 12SIB 11 and 12 can contain information on the maximum of 96 cells (32 intra-frequency cells, 32 inter-frequency cells and 32 GSM cells)On the other hand, the physical size of SIB data (no more than 3552 bits) has capacity only for about (depending on the type etc.) 47 cells!!If too many adjacencies are declared, the cell will go blocked by system with alarm: 7771 WCDMA CELL OUT OF USE (BCCH scheduling error) in RAN04As a rule of thumb, assuming that ADJS=15, ADJG=15, ADJI=15 and realistic worst case values, SIB11 length = 3187.5 < 3552 -> OK!!

Some sites might need additional neighbors and might pose a problem with the SIB11 limitationAvoid setting AdjsQoffset2 values, different CPICH values or other parameters used to tune cell reselection or handoverFurther information Technical Note No. 046 / Restriction on number of cells in SIB11/12 due to inconsistency problem in 3GPP TS 25.331

* 2006 Nokia

* 2006 Nokia Soft Handover HC supports the following measurement reporting events and features:Event 1A: A primary CPICH enters the reporting range (Ncell addition)Event 1B: A primary CPICH leaves the reporting range (Ncell deletion)Event 1C: A non-active CPICH becomes better than an active primary CPICH (Ncell replacement)Cell individual offsets for modifying measurement reporting behaviourMechanism for forbidding a neighbor ing cell to affect the reporting range

Handover decision performed by RNC based on measurements and available resources Admission Control can reject the branch addition in case the maximum load is achieved in DL (threshold + offset), valid both for RT and NRT bitrates.Hard blocking may prevent branch addition

* 2006 Nokia

* 2006 Nokia SHO: Measurement AveragingThe Handover measurement is based on CPICH Ec/IoThe accuracy of pilot Ec/Io measurements is important for Handover performanceMeasurement accuracy depends on the filtering length and mobile speed.When a MS moves slowly or is stationary, filtering length (in ms) has to be just long enough to avoid fast fades leading to errors and causing unnecessary Handovers within a short period.Long filtering length will cause Handover delays to fast moving MSUE can perform averaging on EC/IO measurement prior to the event reporting processEcNoFilterCoefficient (FMCS) defines the filtering period for intra-frequency CPICH EC/IO measurements used by UE (default = 200ms)Similar filter than in Higher Layer Filtering of common and dedicated BTS measurementsRNC averages CPICH Ec/Io measurements using EcNoAveragingWindow (HOPS)defines the number of event triggered or periodic intra-frequency measurement reports used by RNC to calculate averaged CPICH EC/IO (default = 8 Measurements)Used for intra-frequency hard handovers

* 2006 Nokia

* 2006 Nokia 1A: A Primary CPICH Enters the Reporting RangeReporting range defined by offset (point 1 on next slide) from either(i) best CPICH Ec/Io in the AS, or (ii) sum of the AS measurement results set using ActiveSetWeightingCoefficient (FMCS) (0 = use best CPICH : 0 = use sum)Offset defined using AdditionWindow (FMCS)Event 1A triggered when CPCIH3 Ec/Io enters UE reporting range (point 2)If CPICH3 Ec/Io remains within reporting range for a time period defined by AdditionTime (FMCS) , and the AS is not full, UE sends measurement report to RNC which adds Ncell3 to AS if possible (point 3)AdditionTime defines the 'time-to-trigger' interval between the Ncell first entering the reporting range and the UE sending the measurement report to the RNCIf RNC is unable to add Ncell to AS, UE will wait for a period of time, defined by AdditionReportingInterval (FMCS) (point 4) after the first measurement report, before sending further reports periodically, with interval AdditionReportingInterval, until (a) Ncell moves out of reporting range, or (b) RNC adds Ncell to AS.

* 2006 Nokia

* 2006 Nokia 1A: A Primary CPICH Enters the Reporting RangeStrongest CPICH in AStimeEc/IoP CPICH 3P CPICH 1P CPICH 2AdditionWindowAdditionTimeAdditionReportingIntervalRNCMeasurement ReportAdd tothe AS?noActiveSetWeightingCoefficient

* 2006 Nokia

* 2006 Nokia 1A: A Primary CPICH Enters the Reporting RangeReporting criteria of event 1A in 25.331/RRC Measurement Control :Reporting Cell Status: All active cells + 2 monitored cells.

Triggering Condition: Monitored Set cells

Reporting Range Constant AdditionWindow / 4 dB

Cells forbidden to affect Reporting range: AdjsDERR / Enable

W: ActiveSetWeightingCoefficient / 0

Time to trigger: AdditionTime / 0 = 0 ms

Reporting deactivation threshold: MaxActiveSetSize = 3

Amount of reporting: infinity

Reporting interval: AdditionReportingInterval / O.5 s

* 2006 Nokia

* 2006 Nokia 1B: A Primary CPICH Leaves the Reporting RangeEvent 1B triggered when CPICH3 EC/I0 drops out of the UE reporting range for a defined period of time (point 1 on next slide)

Reporting range = Strongest CPICH in AS - DropWindow (FMCS) (point 2)

Time-to-trigger period set using DropTime (FMCS) (point 3)

UE sends RNC measurement report on expiry of DropTime to remove Ncell (CPICH3) from AS.

RNC drops the cell from the AS and UE drops the cell from the AS to the Neighbour Set

* 2006 Nokia

* 2006 Nokia Strongest CPICH in AStimeEc/IoP CPICH 3P CPICH 1P CPICH 2DropWindowDropTimeMeasurement Report1B: A Primary CPICH leaves the Reporting RangeRemove the reported cell from the AS

* 2006 Nokia

* 2006 Nokia 1B: A Primary CPICH Leaves the Reporting RangeReporting criteria of event 1B in 25.331/RRC Measurement Control :

Reporting cell Status: 3 active cells

Triggering Condition: Active cells

Reporting Range Constant: DropWindow / 4 dB

Cells forbidden to affect Reporting range AdjsDERR / Enable

W : ActiveSetWeightingCoefficient / 0

Time to trigger: DropTime / 320 ms

* 2006 Nokia

* 2006 Nokia reportCriteria intraFreqReportingCriteria : { eventCriteriaList { { event e1a : { triggeringCondition monitoredSetCellsOnly, reportingRange 4, w 0, reportDeactivationThreshold t2, reportingAmount ra-Infinity, reportingInterval ri0-5 }, hysteresis 0, timeToTrigger ttt100, reportingCellStatus allActiveplusMonitoredSet : viactCellsPlus2 } event e1b : { triggeringCondition activeSetCellsOnly, reportingRange 6, w 0 }, hysteresis 0, timeToTrigger ttt640, reportingCellStatus withinActiveSet : e3 },Extract from SIB 11SIB 11 contains the relevant parameters to read when in idle modeThese are valid in connected mode prior to receiving the measurement control that overwrites themIn this example:Addition window= 2 dB (factor of 2 mapping between the signalled value and the actual value, TS 25.331 defines this mapping)Addition time = 100 msReporting interval = 500 msDrop window = 3 dB (factor of 2 mapping between the signalled value and the actual value)Drop time = 640 msSoft and Softer Handover (case1)

* 2006 Nokia

* 2006 Nokia 1C: A non-active CPICH becomes better than an active primary CPICH

UE AS full (MaxActiveSetSize = 3) Event 1C triggered when CPICH4 EC/IO > CPICH3 in AS by a defined margin, ReplacementWindow (FMCS). (point 1 in next slide)Sending of measurement report to RNC can be delayed by using 'time-to-trigger' period set by ReplacementTime (FMCS)If 'time-to-trigger' is used difference between CPICH4 and CPICH3 must be ReplacementWindow for the period of ReplacementTime (point 2)If the RNC is not able to replace the Ncells, the UE continues to send measurement reports periodically, with interval ReplacementReportingInterval, to the RNC until (a) CPICH4 falls out of ReplacementWindow or (b) RNC replaces CPICH4 by CPICH3 (point 3)

* 2006 Nokia

* 2006 Nokia timeweakest CPICH3 in ASEc/IoP CPICH 3P CPICH 1P CPICH 2P CPICH 4AS has 3 cellsReplacementReportingIntervalReplacementWindowReplacementTimeMeasurement ReportRNCAS update?no1C: A non-active CPICH becomes better than an active primary CPICH

* 2006 Nokia

* 2006 Nokia event e1c : { replacementActivationThreshold t3, reportingAmount ra-Infinity, reportingInterval ri0-5 }, hysteresis 4, timeToTrigger ttt100, reportingCellStatus withinActiveSet : e3 }Extract from SIB 11 cont.Soft and Softer Handover (case 2)In this example:Replacement window = 1 dBReplacement time = 100 msReporting interval = 500 msReplacement window requires mapping to its true value according to: 4/(2*2) = 1 dB

There are two mappings first is the signalled value to actual value mapping and second is the way in which hysteresis is applied in the event triggering equation (TS25.331)Once in connected mode the networks sends the same set of information elements via a measurement control messageNokias implementation is that the values in the measurement control message are the same as those within SIB 11Events 6F and 6G are configured in a similar fashion i.e. within SIB 11 and subsequently with a measurement control message

* 2006 Nokia

* 2006 Nokia Individual Ncell Offset &Forbidding Neighbour Cell from Reporting Range

Individual Ncell Offsetcell individual offsets for modifying measurement reporting behavioureffectively 'moves' cell border (shrinks or enlarges cell)offset set using AdjsEcNoOffset (= CPICH Ec/No Offset) (ADJS)offset applied to Primary CPICH measurements before event evaluation by the UE

Forbidding Neighbour Cells from Reporting Rangethe primary CPICH of certain cells can be forbidden from reporting range calculation in some instancescells can be forbidden from reporting range using AdjsDERR (ADJS)

* 2006 Nokia

* 2006 Nokia Individual Ncell Offset timeP CPICH 1P CPICH 2P CPICH 3AdjsEcNoOffsetEnlarging Cell 3 by x dBEc/Io

* 2006 Nokia

* 2006 Nokia Forbidding Neighbour Cell from Reporting RangeTimeP CPICH 1P CPICH 2P CPICH 3AdjsDERREc/Io

* 2006 Nokia

* 2006 Nokia Branch additionRRC: Measurement Report (e1a)RRC: Active Set UpdateRRC: Active Set Update CompleteRRC: Measurement Report (e1b)RRC: Active Set UpdateRRC: Active Set Update CompleteUE movingBranch deletionSoft Handover signalling

* 2006 Nokia

* 2006 Nokia Event 1A(Add)Event 1B(Drop)Event 1C(Replace)Active set cells +2 monitored set cellsMonitored set cellsAddition Window/4 dBActive set cellsActive set cellsDrop Window/6 dB

Active set cells +2 monitored set cells-Replacement Window/2 dBAddition Time/100 msAdditionReportingInterval/0.5 sDrop time/640 ms-Replacementtime/100 msReplacementReportingInterval/0.5sEvent Reporting cell statusTriggering ConditionReporting Range/HysteresisTime to TriggerReporting IntervalSHO Summary3GPP reporting events 1A, 1B and 1C (also 6F and 6G)CPICH Ec/Io is used as a measurement quantity rather than CPICH RSCPCPICH Ec/Io measurements are more accurate1A and 1B reporting range is defined by strongest active set cell1C reporting range is defined by weakest active set cell

* 2006 Nokia

* 2006 Nokia RRC Connection Release If difference between the best AS cell and the NS cell is too high and SHO is not performed, the RRC connection is released to avoid excessive interferenceWhy might an AS update not be possible?Excessive load in the neighbor ing cellHard blocking in the target BTSUnavailability of DL spreading codesIub transport resources unavailableThis function is activated by EnableRRCRelease (HOPS parameter)/0=no (def),1 =yesThe RRC connection is released if either:AveEcNoDownlink + ReleaseMarginForAveEcNo(n) < AvEcNoNcell(n)EcNoDownlink + ReleaseMarginPeakEcNo(n) < EcNoNcell(n)ReleaseMarginForAveEcNo (HOPS) = average Eb/N0 margin [-6 6] dB, default 2.5dBReleaseMarginPeakEcNo (HOPS) = peak Eb/N0 margin [-6 6] dB, default 3.5dBEmergency calls are exempt from RRC Connection Release process

* 2006 Nokia

* 2006 Nokia Inter-RNC MobilityMost of the times the UE hands over among WBTS belonging to the same RNC (Intra-RNC Handovers)However, what happens when the target WBTS is under a different WBTS??3GPP gives two different options to handle inter-RNC mobility in WCDMA

Anchoring: the UE will be connected to the CN via the old RNC. It is required Iur connection between the RNCs involvedSRNS relocation: the UE will be connected to the CN via the new RNC. It is the Nokia implemented method

* 2006 Nokia

* 2006 Nokia UE not involved SRNC Relocation for RT SRNC Relocation Decision SRNC operation started UP switching User plane set-up RANAP:Relocation Required RANAP:Relocation Request RANAP:Relocation Request AckRANAP:Relocation complete RRC:UTRAN Mobility InformationRANAP:Relocation Command RNSAP:Relocation Commit RANAP:Relocation Detect RRC:UTRAN Mobility Information ConfirmRANAP:Iu Release RANAP:Iu Release Complete User plane release SRNC Relocation is initiated in the Serving RNC when all the cells of the active set belong to a different RNC. The SRNC sends a Relocation Required The CN evaluates if the relocation is possible and in that case, it sends a Relocation Request to the target RNC with parameters for the bearer establishmentRelocation Command sent from CN to Source RNC with UTRAN information and bearer parametersAfter that, the Source RNC sends Relocation Commit message over Iur to the Target RNC When target RNC starts to act as Serving RNC, it sends a Relocation Detect message to CN. This message has no parameters At the same time UTRAN Mobility Information is sent to the UE, to inform that the relocation is performedAfter the confirm, the target RNC informs CN with Relocation Complete message that the relocation procedure was successful and Iu is released from source RNC Start RelocPrepStop RelocPrep Start RelocOverall Start RelocOverallStop RelocOverallStop RelocOverall RelocationSupport =1NrncRelocationSupport =1

* 2006 Nokia

* 2006 Nokia UE involved: Combined SRNC Relocation and inter-RNC HHO for RTSRNC Relocation Decision L1 sync. Established between BTS and UE UP switching User plane set-up RANAP:Relocation Required RANAP:Relocation Request RANAP:Relocation Request Ack RANAP:Relocation complete Physical Ch Reconfig CompleteRANAP:Relocation Command Physical Channel Reconfiguration RANAP:Relocation Detect RANAP:Iu Release RANAP:Iu Release Complete User plane release Because there is no Iur interface, combined SRNS relocation and HHO are done before the UE is completely under the target RNCThe procedure is quite similar to the not UE involved case until Relocation Command The only difference in the Relocation Required message, the Relocation Type IE is set to "UE involved in relocation of SRNS"

Instead of Relocation Commit via Iur, the serving RNC sends a Physical CH Reconfiguration, after which the UE stops transmitting and receiving on the old radio links and starts on the new radio link

RelocationSupport =1NrncRelocationSupport =1Start RelocPrepStop RelocPrep Start RelocOverallStop RelocOverall Start RelocOverall Stop RelocOverall

* 2006 Nokia

Inter-system Handover (ISHO)

ISHOInter System Handover 3G -> 2G GeneralDownlink DPCH powerUL Quality deteriorationUE Tx powerCPICH RSCPCPICH Ec/I0RAN Internal measurementsConfigured UE measurementsInitiate Compressed ModeConfigure GSM measurementsUE Reports GSM RSSI measurementsGSM CellMeets HO condition ?Initiate HandoverInitiate Compressed ModeConfigure GSM measurementsPSCSUE Reports GSM BSIC measurements

* 2006 Nokia Decision AlgorithmUE Tx Power (Event 6A)Threshold:GsmUETxPwrThrXX L3 filter: GsmUETxPwrFilterCoeffHysteresis margin: GsmUETxPwrTimeHystData rate threshold HHOMAxAllowedBitrateULUL QualityTimer:ULQualDetRepThresholdData rate threshold HHOMAxAllowedBitrateUL

DL DPCH powerThreshold: GsmDLTxPwrThrXXData rate threshold HHOMAxAllowedBitrateDL(XX=AMR,CS,NrtPS,RtPS)CPICH RSCP (Event 1F)Thresholds:HHoRscpThreshold HHoRscpCancelL3 filter: HHoRscpFilterCoefficientTimers:HHoRscpTimeHysteresisHHoRscpCancelTimeCPICH Ec/Io (Event 1F)Thresholds:HHoEcNoThresholdHHoEcNoCancelL3 filter:Done already for SHOTimers:HHoEcNoTimeHysteresisHHoEcNoCancelTimeAdjgTxPwrMaxTCHAdjgRxLevMinHO (n)GsmMeasAveWindowGsmMeasRepIntervalGsmNcellSearchPeriodGsmMinMeasIntervalGsmMaxMeasPeriodHandover TriggeringHandover Execution2G-to-3G back prevention

GsmMinHoIntervalGSM measurement reportingISHO parameters2 more optional triggers in RAN04:

IMSI based ISHO Emergency ISHO (EMISHO)

* 2006 Nokia

* 2006 Nokia Measurement Control Parameters: FMCGMaximum allowed duration of the inter-system measurement is calculated:GSMMeasRepInterval * GSMMaxMeasPeriod (=0.5*20s) =10s, This seems to be too long time, because based on field measurements BSIC and RSSI delays are about 3 seconds, so it makes senses to reduce the value of this parameter to some value about 3 seconds, otherwise, if the BSIC or RSSI measurements fail or if the IS-HO execution is not possible to due low GSM RSSI levels, the network will not deactivate compressed mode until the timer of 10 seconds has expired. Thus, decreasing the parameter value will allow the UE/network to initiate a new IS-HO attempt. Proposed value for GSMMaxMeasPeriod is 6GSMNcellSearchPeriod: 0 This is neighbor cell search period parameter, ISHO is not allowed until the are enough measurement reports given by this parameterO means that only 1 measurement result is enough for decision makingDuration of the cell search period is calculated: GSMRepInterval * GSMNcellSearchPeriod).

* 2006 Nokia

ISHO Process Overview HO Triggering Thresholds set in RNCEvent Triggered Coverage/Capacitybased HO fulfilled in RNCRNC commands selected UE(s) to startIF/IS measurementsMeasurements are done in Compressed Mode (CM)UE reports GSM cells withstrongest RSSI signals to RNCRNC makes HO decision andcommands UE to target cellRSSI measurements and BSICverification for GSM cellsDifferent decision methods for IF HOOnly one decision method for IS HO5 Coverage/Capacity HO Reasons About 25 HO parametersReporting cells are active set cells (max 3) + max 6 IFHO, max 6 ISHO neighb.Max 32 neighbours could be measured(31 Intra-Freq neighbours)48 Inter-Freq neighbours 32 Inter-System neighbours can be measured

* 2006 Nokia BSIC verification always performed for AMR calls no interrupt in voice callISHO 3G -> 2G - AMR Signalling Flow

* 2006 Nokia

* 2006 Nokia In most cases BSIC verification is not required (data interrupt as UE moves to 2G)PS makes use of RRC: CELL CHANGE ORDER FROM UTRAN messageUENode BRNCRRC: Measurement ReportRRC: Measurement ControlNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyNBAP: Radio Link Reconfiguration CommitRRC: Physical Channel ReconfigurationRRC: Physical Channel Reconfiguration CompleteNBAP: Compressed Mode CommandRRC: Measurement ReportRRC: Measurement ControlGSM RSSI MeasurementISHO triggering (5 reasons are possible)Initial Compressed Mode ConfigurationCNRANAP: SRNS Context RequestRANAP: SRNS Context ResponseRANAP: IU Release CommandRANAP: IU Release CompleteRRC: Cell Change Order from UTRANRANAP: SRNS Data Forward CommandISHO 3G -> 2G - PS Signalling Flow

* 2006 Nokia

3G -> 2G Handover measurement triggering

IS Handover Triggering Reasons1. DL DPCH approaches itsmaximum allowed powerFMCI: IFHOcauseTxPwrDLFMCG: GSMcauseTxPwrDL2. Quality deterioration report from UL outer loop PCFMCI: IFHOcauseUplinkQualityFMCG: GSMcauseUplinkQuality4. UE Tx power approaches itsmaximum allowed power, event 6A/6DFMCI: IFHOcauseTxPwrULFMCG: GSMcauseTxPwrUL5 . Low measured absoluteCPICH RSCP, events 1E/1FFMCI: IFHOcauseCPICHrscp, FMCG: GSMcauseCPICHrscp

3. Low measured absolute CPICH Ec/No, event 1E/1F FMCI: IFHOcauseCPICHEcNoFMCG: GSMcauseCPICHEcNo

HO trigger6 . Others (Not implemented in RAN 1.5): e.g. Traffic & load reason IS-HO, etc Frequency Measuring Control for Inter-Frequency = FMCIFrequency Measuring Control for Inter-System (GSM) = FMCG

Measurement triggering: CPICH Ec/NoReporting event: 1E: A P-CPICH exceeds an absolute threshold (triggered if one) 1F: A P-CPICH falls below an absolute threshold (triggered if all)e.g. P-CPICH Ec/No

Measurement triggering: CPICH Ec/NoRNC starts IF/IS measurement when event 1F occurs for all cells in the active set: A Primary CPICH becomes less than an absolute thresholdRNC stops IF/IS measurement when event 1E occurs for at least one cell of the active set : A Primary CPICH becomes better than an absolute thresholdNote:IF/IS measurements can be stopped if event 1Fs are cancelled by events 1E only when IFHO/ISHO was not successful and only inside the time between CMmeasurements, specifiedby the time InterFreqMinMeasInterval ,GsmMinMeasInterval/default 10s, recommendation 2s . Filtering applied before event evaluation in the UE: FMCS: EcNoFilterCoefficient/0= 200ms filtering period

Measurement triggering: CPICH Ec/NoEvent 1E parameters:Triggering conditions: Active set cellsHysteresis: not used in 1FThreshold used frequency: FMCS : HHoEcNoCancel/ -9dBTime-to-trigger: FMCS: HHoEcNoCancelTime/ 1280 msAmount of reporting: infinityReporting interval: not applied.Reporting cell status: max 3 active cells.Event 1F parameters:Triggering conditions: Active set cellshysteresis: not used in 1FThreshold used frequency: FMCS : HHoEcNoThreshold / - 12dB (range 0..-24 dB)Time-to-trigger: FMCS: HHoEcNoTimeHysteresis / 100 ms (range 0..5000ms)Amount of reporting: infinityReporting interval: not applied.Reporting cell status: max 3 active cells.

Measurement triggering: CPICH RSCPReporting event: 1E: A P-CPICH exceeds an absolute threshold (triggered if one) 1F: A P-CPICH falls below an absolute threshold (triggered if all)timeCell 1Cell 2Cell 3absolute thresholde.g. P-CPICH Rscp1E: HHoRscpCancel1E: HHoRscpCancelTime1F: HHoRscpThreshold1F: HHoRscpTimeHysteresis

Measurement triggering: CPICH RSCPUE continually monitors pilot channels of BTSs in ASIf RSCP of a Node B falls below threshold, HHoRscpThreshold, UE sends event 1F reportRNC starts IF/IS measurements when event 1F occurs for all cells in ASRNC stops IF/IS measurements when event 1E occurs for at least one cell of ASNote:IF/IS measurements can be stopped if event 1Fs are cancelled by events 1E only when IFHO/ISHO was not successful and only inside the time between CMmeasurements, specifiedby the time InterFreqMinMeasInterval GsmMinMeasInterval/default 10s, recommendation 2s .UE filtering applied before event evaluation using HHoRscpFilterCoefficient (FMCS) /200ms, range 2001600ms

Measurement triggering: CPICH RSCPEvent 1E (A primary CPICH exceeds an absolute threshold) parameters:Triggering conditions: Active set cellshysteresis: not used in 1EThreshold used frequency: (FMCS) : HHoRscpCancel/ - 90 dBmTime-to-trigger: (FMCS): HHoRscpCancelTime/ 1280 msAmount of reporting: infinityReporting interval: not applied.Reporting cell status: max 3 active cells.

Event 1F (A primary CPICH falls below an absolute threshold) parameters:Triggering conditions: Active set cellsHysteresis: not used in 1FThreshold used frequency: HHoRscpThreshold (FMCS)/ - 93 dBmTime-to-trigger: HHoRscpTimeHysteresis (FMCS)/ 100 msAmount of reporting: infinityReporting interval: not applied.Reporting cell status: max 3 active cells.

3G -> 2G Measurements

Decision AlgorithmUE Tx Power (Event 6A)Threshold:GsmUETxPwrThrXX L3 filter: GsmUETxPwrFilterCoeffHysteresis margin: GsmUETxPwrTimeHystData rate threshold HHOMAxAllowedBitrateULUL QualityTimer:ULQualDetRepThresholdData rate threshold HHOMAxAllowedBitrateUL

DL DPCH powerThreshold: GsmDLTxPwrThrXXData rate threshold HHOMAxAllowedBitrateDL(XX=AMR,CS,NrtPS,RtPS)CPICH RSCP (Event 1F)Thresholds:HHoRscpThreshold HHoRscpCancelL3 filter: HHoRscpFilterCoefficientTimers:HHoRscpTimeHysteresisHHoRscpCancelTimeCPICH Ec/Io (Event 1F)Thresholds:HHoEcNoThresholdHHoEcNoCancelL3 filter:Done already for SHOTimers:HHoEcNoTimeHysteresisHHoEcNoCancelTimeAdjgTxPwrMaxTCHAdjgRxLevMinHO (n)GsmMeasAveWindowGsmMeasRepIntervalGsmNcellSearchPeriodGsmMinMeasIntervalGsmMaxMeasPeriodHandover TriggeringHandover Execution2G-to-3G back prevention

GsmMinHoIntervalGSM measurement reportingISHO parameters

ISHO measurementsAfter HO triggering message is sent to RNC, a RRC message Measurement Control is sent to UE containing details of the measurement that the UE must execute. Measurement reporting is periodical. Max 6 GSM cells could be measured by UE and reported to RNC. No filtering in measurements by UE

Upon reception of the measurements reported by the UE, RNC applies a sliding averaging window to the RXLEV measurements. The averaged levels are used as input to the IS-HO decision algorithm.RNCRRC: Measurement control message (GSM RSSI measurements)UEThe first measurement report has info from the best GSM cell: BCCH freq & RSSI, no filteringused in UE

Measurement Control Parameters: FMCGGSMMeasRepInterval: 0.5 secondsThis is the interval between measurement reports, which are sent to BTSThis parameter should be kept to 0.5 seconds. Increasing the reporting interval would increase the IS-HO process delay.GSMMinMeasInterval: 2 sThis is Minimum Measurement Interval, wait time when the following CM starts. In case of an unsuccessful IS-HO attempt, the network will deactivate compressed mode for a time period given by this parameter, thus better value will be 2 s to speed up the reactivation of CM.GSMMeasAveWindow: 6 reportsThis is Measurement Averaging Window size, sliding window is usedGSMMaxMeasPeriod: 12 reportsThis is Maximum Measurement Period which determines the maximum allowed duration of the inter-system measurementIf the RNC is not able to execute an inter-system handover, it shall stop the inter-system measurements after the UE has sent the predefined number of measurement reports to the RNC.

Measurement Control Parameters: FMCGMaximum allowed duration of the inter-system measurement is calculated:GSMMeasRepInterval * GSMMaxMeasPeriod (=0.5*12) =6s, This seems to be too long time, because based on field measurements BSIC and RSSI delays are about 3 seconds, so it makes senses to reduce the value of this parameter to some value about 3 seconds, otherwise, if the BSIC or RSSI measurements fail or if the IS-HO execution is not possible to due low GSM RSSI levels, the network will not deactivate compressed mode until the timer of 10 seconds has expired. Thus, decreasing the parameter value will allow the UE/network to initiate a new IS-HO attempt. Proposed value for GSMMaxMeasPeriod is 6

GSMNcellSearchPeriod: 0 This is neighbour cell search period parameter, ISHO is not allowed until the are enough measurement reports given by this parameterO means that only 1 measurement result is enough for decision makingDuration of the cell search period is calculated: GSMRepInterval * GSMNcellSearchPeriod).

ISHO: BSIC VerificationAfter the selection of the target GSM cell, the RNC sends to UE the RRC message "Measurement control which includes details to measure BSIC . UE stops RSSI measurements and updates the transmission gap pattern to the pattern used for BSIC decoding. The measurement reports are sent periodically to RNC. If the UE is unable to decode the BSIC during the given period, the BSIC measurement operation is aborted.

RNCRRC: Measurement control message (BSIC decoding)WCDMAIS-HO trigger Target Cell found IS-HO commandRSSI meas.BSIC verification

Numbers of GSM cells in the neighbour cell listReporting intervalSliding averaging windowTransmission gap pattern for RSSI measurements TBSIC depends on :

Transmission gap pattern for BSIC decoding

TRSSI depends on

3G -> 2G Handover decision

On this page, you find conditions, which have to be satisfied, before an inter-frequency handover can be conducted. The best neighbouring cell must fulfil following criterion (best according to Ec/No): AVE_RXLEV_NCell(n) > GSMncellRxLevMinHO(n) + max(0, GSMncellTxPwrMaxTCH(n) - P_max)

whereAVE_RXLEV _Ncell(n) is the averaged GSM carrier RSSI value of the GSM neighbour cell(n), averaging done directly from dBm values (no linear averaging); GSMMeasAveWindow / 6, 132 meas report. GSMncellRxLevMinHO(n) determines the minimum Required RSSI (dBm) level of the neighbour cell(n). ( -95 dBm)GSMncellTxPwrMaxTCH(n) indicated the maximum Tx power level (dBm) an UE may use in GSM neighbour cell(n).P_MAX is the maximum UE power capability.

If several GSM cells fulfils the equation above, cells are ranked based on HOPG: GSMncellPriorityCoverage/0, range 07A cell is ranked higher than another cell if it has a higher priority level even though its signal strength condition was worseInter-system HO could be forbidden during the first measurements reports from the UE, to let the UE report all the candidate inter-system cells in its neighbourhood.FMCG FMCGNcellSearchPeriod / 0

Inter-RAT HO Decision

AdjgRxLevMinHO(n)max(0, AdjgTxPwrMaxTCH(n) - P_max)AVE_RXLEV_NCell(n) > AdjgRxLevMinHO(n) + max(0, AdjgTxPwrMaxTCH(n) - P_max)GSM cellISHO Decision

3G -> 2G Handover signalling

ISHO IS TRIGGEREDEVENT 1F -(48-32)/2 = -8 dB -8.5 EcNo < -8-115 + 11 = -104 dBm -105 Rscp < -104ISHO analysis with Nemo

RxLev = -110 + 4 = -106 dBm4AdjgRxLevMinHO = -95 dBmPOOR GSM COVERAGE

No suitable cell

AMR Handover procedure overview (1)RRC connection setupISUP signallingParameters for HO event triggere1e, e1f, e6a,e6b

AMR Handover procedure overview (2)ISUP signallingMobility management; several AS cell add & cell drops

AMR Handover procedure overview (3)Compressed Mode ParametersMeasurement report to trigger CMMobility management; several AS cell add & cell drops

AMR Handover procedure overview (4)RNC sends updated GSM NB listUE sends inter RAT meas. ResultsRNC commands UE to verify BSIC ofbest reported cellTarget cell BSIC verifiedRNC triggers HO to GSM target cellTiming advance informationUE ends HHO - procedure UE is handed over to GSM 2G signalling

Physical Channel reconfigurationRRC: Physical Channel reconfiguration

Measurement Control new RAT NB list[..]new inter RAT NB listMeasurement infoRRC: Measurement Control

UE Measurement Report GSM cells-RSSI measurementsmeasured best cell by ARFCNmeasured 2nd best cell by ARFCNmeasured 3rd best cell by ARFCNmeasured 4th best cell by ARFCNmeasured 5th best cell by ARFCNmeasured 6th best cell by ARFCNRRC: Measurement Report

Measurement Control carrying target cell infoRRC: Measurement ControlUE shall stop measuring RSSI of RAT NB list and focus on best cells BSIC verification

UE Measurement Report target GSM cell-BSIC verificationRRC: Measurement ReportUE reports verified BSIC of best cell to RNC

Handover from UTRAN commandRRC: HO from UTRAN command

Handover command GSM signallingL3: Handover command2G cell information (RF&configuration)2G cell information (Security)2G cell information (PC)

Cell Selection and Reselection

2G 3G inter workingIdle modeConnected mode2G -> 3G reselection3G -> 2G reselection2G -> 3G handover CS AMR2G -> 3G handover PS3G -> 2G handover CS AMR3G -> 2G handover PS

3G -> 2G reselection

Cell Reselection Cell Selection S-CcriteriaThe cell selection criteria S are defined as follows:The cell selection criterion S for a suitable cell is fulfilled when:Where:Squal Cell Selection quality value, (dB). Not applicable for TDD cells or GSM cellsSrxlevCell Selection RX level value (dB)QqualmeasMeasured cell quality value. The quality of the received signal expressed in CPICH Ec/N0 (dB) for FDD cells. Not applicable for TDD cells or GSM cells.QrxlevmeasMeasured cell RX level value. This is received signal, CPICH RSCP for FDD cells (dBm), P-CCPCH RSCP for TDD cells (dBm) and RXLEV for GSM cells (dBm).QqualminMinimum required quality level in the cell (dB). Not applicable for TDD cells or GSM cells.QrxlevminMinimum required RX level in the cell. (dBm)Pcompensationmax(UE_TXPWR_MAX_RACH P_MAX, 0) (dB)UE_TXPWR_MAX_RACHMaximum TX power level an UE may use when accessing the cell on RACH (read in system information), (dBm)P_MAXMaximum RF output power of the UE, (dBm)-18dB -115dBm -115dBm -101dBm intraGSMTS 25.304 5.2.3.1.2

Squal = Qqualmeas Qqualmin

Srxlev = Qrxlevmeas - Qrxlevmin - Pcompensation

Squal > 0

Srxlev > 0

_1016983615.doc

Squal > 0

Srxlev > 0

If system info in the cell indicates that HCS is not used (UseOfHCS) then for intra-freq, inter-freq and inter-system the UE shall:If Squal > Sintrasearch, UE need not perform intra-frequency measurements. If Squal Sintersearch, UE need not perform inter-frequency measurements If Squal SsearchRAT m, UE need not perform measurements on cells of RAT "m". If Squal

SintrasearchSintersearchSsearchRATWCDMACELL1234 Sintrasearch = 4 dB: Equate to 16dB Ec/NoSintersearch = 2 dB: Equate to 18dB Ec/NoSsearchRAT m, = 0dB: Equate to 20dB Ec/No

Cell Reselection Cell Selection S-Ccriteria

The following cell re-selection criteria is used for intra-freq, inter-freq & inter-RAT:

Rs = Qmeas,s + Qhysts(COMAPRED WITH SELF)Rn = Qmeas,n Qoffsetn(COMPARED WITH ADJACENT CELLS)Where:Cell Reselection Cell Selection S-Ccriteria

Cell Reselection 3G -> 2GFirst ranking of all the cells based on CPICH RSCP (WCDMA) and RSSI (GSM)

Rs = CPICH RSCP + Qhyst1Rn= Rxlev(n) - Qoffset1Rn (GSM) > Rs (WCDMA)AndRxlev (GSM) >QrxlevMin YesNoCell re-selection to GSM Neighbour WCDMA or GSM cell calculation with offset parameterServing WCDMA cell calculation, with hysteresis parameterUE starts GSM measurements if CPICH Ec/No < qQualMin + sSearchRAT SintraSearchSinterSearchSsearchRATCPICH EcNoqQualMinSecond ranking only for WCDMA cells based on CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn=CPICH_Ec/No(n)-Qoffset2Cell re-selection to WCDMA cell of highest R value Concept

Cell Reselection 3G -> 2G

Cell Reselection Neighbour measurements summarySintrasearchSintersearchSsearchRAT mNo need to measure neighbour cellsIntra-frequencySx=Squal= Ec/NoIntra-frequencyInter-freqencyInter-RATHigher HCS priorityIntra-frequencyInter-frequencyIntra-frequencyInter-frequencyHCS not usedHCS usedSlimitsearchRAT mIntra-frequencyInter-frequencyIntra-frequencyInter-freqencyInter-RATIntra-frequencyInter-frequencyHigher HCS priority inter RAT

There is no timer defined how long the GSM should be fulfilling the re-selection criteria However there is running average of 4 GSM measurements which provides some protection against ping pong (time vice based on DRX cycle length and as sliding window average)In case additional protection is needed it can be arranged by using the Qhyst1 parameter (for WCDMA serving cell RSCP) or AdjgQoffset1 (for GSM neighbouring cell RxLev)PerformanceFirst ranking of all the cells based on CPICH RSCP (WCDMA) and RSSI (GSM)

Rs = CPICH RSCP + Qhyst1Rn= Rxlev(n) - Qoffset1Cell Reselection 3G -> 2G

When to trigger the cell reselection to 2G depends greatly on:how much the 3G network is requested to be utilised target is to maximise the utilisation of WCDMA network butwhat is the desired CSSR at the same time maximise the qualityminimise the possibility of ping pong Due to very different fading conditions, there should be couple of different parameter sets for 3G -> 2G reselectionOutdoor, typical outdoor to dedicated indoor (in case of missing 3G indoor)3G borderSpecial indoor cases without dedicated 3G where the UE speed is high (e.g. tunnels)Parameter TuningGeneralCell Reselection 3G -> 2G

ISHOCell Reselection 3G -> 2GParameter TuningOutdoorAs long as the Ec/No is >-12-14dB the CSSR is excellentqQualMin + sSearchRAT ~ -14dBWCDMA intra frequency search should be started latest at ~ qQualMin + sSearchIntra = -8 -10dB

2G -> 3G reselection

Cell Reselection Algorithm from GSM to FDD-WCDMA (cs)Cell Reselection ListGSM MS starts WCDMA measurements if :RLA_C< F(Qsearch_I) for 0

In GSM the UE is usually set to measure the 3G neighbours all the time I.e. Qsearch_I and Qsearch_P are both set to 7UE starts WCDMA measurements if Rxlev running average (RLA_C) is below or above certain threshold:RLA_C Qsearch_I and Qsearch_P (GPRS)Cell Reselection Algorithm from GSM to FDD-WCDMA (cs)

Cell Reselection ParametersQsearch_I and Qsearch_P define thresholds. The threshold value also indicates, when the measurements have to be initiated and performed. The measurements are either started, when the serving cells RLA is below or above the threshold value. The default value is 15.FDD_Qoffset and FDD_GPRS_Offset define offset values, which have to be added to the RLA of the serving and non-serving GSM cells. The result is compared with the RSCP value of the WCDMA cell. The default parameter is 0. FDD_Qmin defines a minimum CPICH Ec/No threshold for WCDMA cell for cell re-selection.FDD_REP_QUANT defines the reporting quantity for UTRAN cell (1=Ec/No or 0=RSCP, default: 1).3G_Search_PRIO is used to inidicate to the MS if 3G cells can be looked for when BSIC decoding is required. (0=no, 1=yes, default: 1)

The 3G Cell Reselection list is only used by multi-RAT MSs. The system information SI2quater and SI2ter can be used to provide 3G cell information. If the two system information messages carry 3G cell information, than their lists have to be combined in the UEs 3G Cell Reselection list, which may then hold up to 96 UMTS cells. Up to 8 carrier frequency bands can be stored in this list, too.

Cell Reselection AlgorithmAlgorithm for cell re-selection from GSM (GPRS) to the FDD mode in UTRANPre-requisite for cell re-selection to UMTS is, that UTRAN carrier bands are included in the (GPRS) 3G Cell Reselection list. If so, the MS must update RLA_C (RLA_P) value for the serving cell andat least 6 strongest non serving GSM cellsat least every 5 seconds. Thereafter, the MS can re-select a suitable UTRAN cell, based on the S-Criterion. If an FDD cell is suitable, following two conditions must have been met:For a period of 5 seconds, the measured RSCP value must exceed the PLA_C (RLA_P) of the serving GSM and of all non-serving GSM cells by the value FDD_Qoffset (FDD_GPRS_Qoffset). Did a cell re-selection occur within the previous 15 seconds, the FDD_Qoffset value is increased by 5 dB. The measured Ec/No value of the FDD cell must be greater or equal than the broadcasted value FDD_Qmin.If the UE as performed a cell re-selection to UTRAN within the previous 5 seconds, a cell re-selection back to UTRAN is not allowed, when a suitable cell can be found within GSM.

Cell Re-selection ParametersRange of FDD_QminRecommended value is 7 (-13 dBm)

FDD_REP_QUANT defines the reporting quantity for UTRAN cell (1=Ec/No or 0=RSCP, default 1)3G_Search_PRIO parameter allows to extend the BSIC reporting interval from 10 s to 13s by checking the BSICs from non-serving BCCH carriers and also make WCDMA measurements as often as possible. Range is 0=no, 1=yes, default value 1Defined in the SI2quater and PSI3quater if PBCCH is allocated.

Parameter

Name for Sys Info (SI)

Qsearch_I2quaterQsearch_PQsearch_P2quater3quaterFDD_QMin2terFDD_(GPRS)Qoffset2quaterFDD_REP_QUANT2ter3G_search_PRIO2(3)quarter(PBCCH)oldNew mapping from 05.08 [late 2003]:UEs have to support new parameter range !

3G Parameter

Phase 1Phase 2Phase 3

NormalMRT TunnelBorderRemarksGeneralGeneral

Wcell

S intrasearch12dB12dB12dBReselection12dB12dB

S searchRAT2dB10dB6dBReselection2dB2dB?

Cell Reselection Hysteresis 12dB2dB2dBReselection2dB2dB

Min required quality level in Cell-16dB-16dB-16dBReselection-16dB-16dB

Min required Rx level in Cell-115dBm-115dBm-115dBmReselection-115dBm-115dBm

FMCS

CPICH RSCP HHO Cancel-95dBm-90dBm-85dBmHO Control-100 dBm-100 dBm

CPICH RSCP HHO Threshold-100dBm-95dBm-90dBmHO Control-105 dBm-105 dBm

CPICH EcNo HHO Cancel-14dB-12dB-14dBHO Control-14dB-14dB?

CPICH EcNo HHO Threshold-15dB-13dB-15dBHO Control-15dB-15dB?

FMCG

GSM HO Cause By CPICH EcNoDisable (0)Enable (1)Disable (0)HO ControlDisable (0)?Disable (0)?

GSM HO Cause By CPICH RSCPEnable (1)Enable (1)Enable (1)HO ControlEnable (1)Enable (1)

GSM HO Cause By DL DPCH Tx PwrDisable (0)Disable (0)Disable (0)HO ControlDisable (0)Disable (0)

GSM HO Cause By UE Tx PowerDisable (0)Disable (0)Disable (0)HO ControlDisable (0)Disable (0)

GSM HO Cause By UL DCH QualityDisable (0)Disable (0)Disable (0)HO ControlDisable (0)Disable (0)

GSM Neighbour Cell Search Period0 Reports0 Reports0 ReportsHO Control0 Reports0 Reports

Maximum Measurement Period20 Reports20 Reports20 ReportsHO Control20 Reports20 Reports

Measurement Averaging Window6 Reports6 Reports6 ReportsHO Control6 Reports6 Reports

Measurement Reporting Interval0.5s0.5s0.5sHO Control0.5s0.5s

Minimum Interval between HO10s10s10sHO Control10s10s

Minimum Measurement Interval10s10s10sHO Control10s10s

NormalMRT TunnelBorderRemarksGeneralGeneral

HOPG

Cell Relection Quality Offset 10-20dB0Reselection00

Cell Relection Minimum Rxlev-95dBm-105dBm-95dBmReselection-95dBm-95dBm

Min RxLev for Coverage HO-9