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Content for  TS 25.225  Word version:  16.0.0

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1  ScopeWord‑p. 6

The present document contains the description and definition of the measurements done at the UE and network in TDD mode in order to support operation in idle mode and connected mode.

2  References

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
  • References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
  • For a specific reference, subsequent revisions do not apply.
  • For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
TS 25.211: "Physical channels and mapping of transport channels onto physical channels (FDD)".
TS 25.212: "Multiplexing and channel coding (FDD)".
TS 25.213: "Spreading and modulation (FDD)".
TS 25.214: "Physical layer procedures (FDD)".
TS 25.215: "Physical layer measurements (FDD)".
TS 25.221: "Physical channels and mapping of transport channels onto physical channels (TDD)".
TS 25.222: "Multiplexing and channel coding (TDD)".
TS 25.223: "Spreading and modulation (TDD)".
TS 25.224: "Physical layer procedures (TDD)".
TS 25.301: "Radio Interface Protocol Architecture".
TS 25.302: "Services provided by the Physical layer".
TS 25.303: "UE functions and interlayer procedures in connected mode".
TS 25.304: "UE procedures in idle mode".
TS 25.331: "RRC Protocol Specification".
TR 25.922: "Radio Resource Management Strategies".
TR 25.923: "Report on Location Services (LCS)".
→ to date, withdrawn by 3GPP
TS 25.102: "UTRA (UE) TDD; Radio transmission and Reception"
TS 25.105: "UTRA (BS) TDD; Radio transmission and Reception"
TS 25.123: "Requirements for Support of Radio Resources Management (TDD)"
TS 36.211: "E-UTRA; Physical Channels and Modulation"
TS 36.214: "E-UTRA; Physical layer - Measurements"
IEEE 802.11, Part 11: "Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, IEEE Std.".

3  AbbreviationsWord‑p. 7

For the purposes of the present document, the following abbreviations apply:
Broadcast Channel
Broadcast Control Channel (GSM)
Bit Error Rate
Block Error Rate
Connection Frame Number
Common Pilot Channel (FDD)
Cyclic Redundancy Check
Dynamic Channel Allocation
Dedicated Channel
Dedicated Physical Channel
Received energy per chip divided by the power density in the band
E-DCH Absolute Grant Channel
E-DCH Hybrid ARQ Indicator Channel
Evolved Universal Terrestrial Radio Access
Forward Access Channel
Frequency Correction Channel (GSM)
Frequency Division Duplex
Global System for Mobile Communication
Global Positioning System
Interference Signal Code Power
Primary Common Control Physical Channel
Paging Channel
Public Land Mobile Network
Physical Random Access Channel
Physical Downlink Shared Channel
Physical Uplink Shared Channel
Random Access Channel
Received Signal Code Power
Reference Signal Received Power
Reference Signal Received Quality
Received Signal Strength Indicator
Secondary Common Control Physical Channel
Synchronisation Channel
Space Code Transmit Diversity
Spreading Factor
System Frame Number
Signal-to-Interference Ratio
Time Division Duplex
Time Division Multiple Access
Transport Channel
Transmission Time Interval
User Equipment
Universal Mobile Telecommunications System
Uplink Shared Channel
UMTS Terrestrial Radio Access
UMTS Terrestrial Radio Access Network

4  Control of UE/UTRAN measurements

In this clause the general measurement control concept of the higher layers is briefly described to provide an understanding on how L1 measurements are initiated and controlled by higher layers.

4.1  General measurement conceptWord‑p. 8

L1 provides with the measurement specifications a toolbox of measurement abilities for the UE and the UTRAN. These measurements can be differentiated in different measurement types: intra-frequency, inter-frequency, inter-system, traffic volume, quality and internal measurements (see [14]).
In the L1 measurement specifications the measurements are distinguished between measurements in the UE (the messages will be described in the RRC Protocol) and measurements in the UTRAN (the messages will be described in the NBAP and the Frame Protocol).
To initiate a specific measurement the UTRAN transmits a 'measurement control message' to the UE including a measurement ID and type, a command (setup, modify, release), the measurement objects and quantity, the reporting quantities, criteria (periodical/event-triggered) and mode (acknowledged/unacknowledged), see [14].
When the reporting criteria is fulfilled the UE shall answer with a 'measurement report message' to the UTRAN including the measurement ID and the results.
In idle mode the measurement control message is broadcast in a System Information.
Intra-frequency reporting events, traffic volume reporting events and UE internal measurement reporting events described in [14] define events which trigger the UE to send a report to the UTRAN. This defines a toolbox from which the UTRAN can choose the needed reporting events.

4.2  Measurements for cell selection/reselection

Whenever a PLMN has been selected the UE shall start to find a suitable cell to camp on, this is 'cell selection'.
When camped on cell the UE regularly searches for a better cell depending on the cell reselection criteria, this is called 'cell reselection'. The procedures for cell selection and reselection are described in [13] and the measurements carried out by the UE are explained in this specification.

4.3  Measurements for Handover

For the handover preparation the UE receives from the UTRAN a list of cells (e.g. TDD, FDD or GSM).which the UE shall monitor (see 'monitored set' in [14]) in its idle timeslots.
At the beginning of the measurement process the UE shall find synchronization to the cell to measure using the synchronization channel. This is described under 'cell search' in [9] if the monitored cell is a TDD cell and in [4] if it is an FDD cell.
For a TDD cell to monitor after this procedure the exact timing of the midamble of the P-CCPCH is known and the measurements can be performed. Depending on the UE implementation and if timing information about the cell to monitor is available, the UE may perform the measurements on the P-CCPCH directly without prior SCH synchronisation.

4.4  Measurements for DCA

DCA is used to optimise the resource allocation by means of a channel quality criteria or traffic parameters. The DCA measurements are configured by the UTRAN. The UE reports the measurements to the UTRAN.
For DCA no measurements are performed in idle mode in the serving TDD cell.
When connecting with the initial access the UE immediately starts measuring the ISCP of time slots which are communicated on the BCH. The measurements and the preprocessing are done while the UTRAN assigns an UL channel for the UE for signalling and measurement reporting.
In connected mode the UE performs measurements according to a measurement control message from the UTRAN.

4.5  Measurements for timing advance

To update timing advance of a moving UE the UTRAN measures 'Received Timing Deviation', i.e. the time difference of the received UL transmission (PRACH, DPCH, PUSCH) in relation to its timeslot structure that means in relation to the ideal case where an UL transmission would have zero propagation delay. The measurements are reported to higher layers, where timing advance values are calculated and signalled to the UE.

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