TSG-RAN WG2 #49
`Seoul, Korea, 07-11 Nov 2005
`
`Source:
`Title:
`Agenda Item:
`Document for:
`
`
`Ericsson
`Filtering for UE Power Headroom Measurement
`9.2
`Discussion and Decision
`
`R2-052744
`
`Introduction
`1.
`At the RAN1#42 meeting in London, UK, 29 Aug – 02 Sept 2005, RAN1 discussed the UE power headroom
`measurement.
`The result of this discussion is that the UE power headroom measurement is defined as:
`UE transmission power headroom (UPH) is the ratio of the maximum UE transmission power and the
`corresponding DPCCH code power, and shall be calculated as following:
`UPH
`P tx Pmax, DPCCH
`
`/
`=
`
`
`
`
`
`
`where:
`Pmax,tx = min {Maximum allowed UL TX Power, Pmax} is the UE maximum transmission power;
`Maximum allowed UL TX Power is set by UTRAN and defined in TS 25.331;
`Pmax is the UE nominal maximum output power according to the UE power class and specified in TS 25.133
`table 6.1;
`PDPCCH is the transmitted code power on DPCCH.
`The exact definition is specified in RAN1 Specification [4].
`This contribution discusses Layer 3 filtering for the UE Power Headroom measurement and includes proposals
`for text in applicable specifications.
`
`2. Discussion
`The UE physical layer measures the UE Power Headroom on a slot basis; after filtering over a measurement
`period, e.g. 2ms, the measurement is delivered to higher layers. After some processing by the UE, the UPH
`information is further sent to the node B together with other control information (Figure 1).
`
`Filtering
`Mn +1 Mn +2
`
`Mn
`
`UPH in MAC-e
`
`
`L1 Measurement period
`
`Measurement reporting delay
`
`
`Figure 1 UPH Measurement and reporting - illustration
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`HTC/ZTE Exhibit 1004
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`The UPH information bits are sent in the Scheduling Information, SI, appended at the end of the MAC-e PDU.
`The periodicity of the Scheduling Information sent to node B is defined in the order of TTI, with 1 TTI as the
`shortest report period and is configurable through RRC signaling. Note that apart from the configurable
`periodicity, the inclusion of SI can be made arbitrarily, if for instance padding allows it or if triggered by higher
`priority data entering the UE buffer.
`The UE should include the latest measurement to the network. It is in e.g. [2] proposed to specify the minimum
`requirements for a UPH measurement reporting delay, which is defined as the maximum time between the end of
`the UPH measurement and the start of the UPH measurement reporting.
`From a RAN2 point of view the question is what kind of filtering that would be required in order to
`accommodate the requirements from RAN4 specifications using the current definition of UPH.
`In RAN4 the topic has been discussed [1], [2], and it is expected that requirements will be defined with regards
`to:
`
`• Layer-1 filtering (e.g. measurement period)
`• Accuracy requirements (e.g. Value range -> Number of bits)
`Impact of compressed mode
`•
`• Measurement Reporting Delay
`
`•
`
`
`While it still remains to be decided on many of these points, the basis for defining the Layer 3 filtering in RAN2
`can still be made:
`• Layer-1 filtering: Processing/filtering is executed at the end of a L1 measurement period as defined in
`[5]. The proposed layer 3 filtering can be defined independently of this.
`• Accuracy: The value range (i.e. number of bits) and accuracy for UPH is defined in RAN4[5]. A
`proposal [2] having 5 bits is discussed. A separate CR for User Control Data should be discussed in
`RAN2 [6].
`Impact of compressed mode: No measurement will be reported from the physical layer [2]. The
`proposed filtering can be defined independently of this.
`• Measurement Reporting Delay: Requirements in [5]. The proposed filtering can be defined
`independently of this.
`This means that in order to specify the filtering, parameters in 25.321 and filtering coefficient in 25.331, it has
`been identified the following considerations remain:
`• Assuming that the Physical 1ayer delivers a measurement Mn at the end of each measurement period
`and filtering is according to section 8.6.7.2 in 25.331 (see Annex A), the options to consider for the
`filtering coefficient(s) are:
`o The filtering coefficient is a fixed value
`o
`Is signaled by RRC
`o
`Is defined by the periodicity (RRC signaled) of the Scheduling Information
`Now, considering the options above. If a fixed value is used this does not take into account the dependability on
`a static vs. dynamic environment, the number of measurements from L1 (periodicity of SI) and so on. For this
`case one would need to simulate and evaluate what typically the coefficients would be.
`From this point of view it would be an advantage of allowing for “tuned” coefficients depending on the
`operation of the NW and the actual use of user control information. Having a UE internal scheme with a
`coefficient depending on the periodicity of the SI could be one option, but then it would require the UE, apart
`from other issues like testing, store a table with corresponding values and adds to the complexity of the filtering.
`Proposal: It is proposed that the layer 3 filtering coefficient(s) is signaled in RRC and is based on the existing
`requirements in 3GPP TS 25.331 as outlined in this document and accompanied CR [6].
`
`
`3. Conclusion
`It is proposed that RAN2 discusses the issue and decides on the inclusion of the Layer 3 filtering coefficients in
`25.331. The outcome could be reported back to RAN4 for feedback.
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`HTC/ZTE Exhibit 1004-2
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`4. References
`[1] R4-050936 UE power headroom, MAC filtering and way forward, Panasonic
`[2] R4-051125, Requirements for UE Power Headroom, Ericsson
`[3] R2-052462 LS on UE power headroom measurement
`[4] 3GPP TS 25.215, ‘Physical Layer - Measurements’.
`[5] 3GPP TS 25.133: "Requirements for Support of Radio Resource Management (FDD)".
`[6] Proposed CR to 25.331 [Rel-6] on UE power headroom, Ericsson
`
`
`
`Annex A - Text reproduced from 3GPP 25.331
`
`---- Omitted text ---
`
`Filter coefficient
`8.6.7.2
`If the IE "Filter coefficient" is received the UE shall, depending on the measurement quantity (see Table 8.6.7.2),
`apply filtering of the measurements for that measurement quantity according to the formula below. This filtering
`shall be performed by the UE before UE event evaluation. The UE shall depending on the reporting quantity (see
`Table 8.6.7.2), also filter the measurements reported in the IE "Measured results". The filtering shall not be
`performed for the measurements reported in the IE "Measured results on RACH" and for cell-reselection in
`connected or idle mode.
`The filtering shall be performed according to the following formula.
`F
`
` Fa)
`Ma
`1(
`⋅
`−
`=
`⋅+
`
`n
`n
`
`
`
`n
`
`−1
`
`The variables in the formula are defined as follows:
`Fn is the updated filtered measurement result
`Fn-1 is the old filtered measurement result
`Mn is the latest received measurement result from physical layer measurements, the unit used for Mn is the
`same unit as the reported unit in the MEASUREMENT REPORT message or the unit used in the event
`evaluation.
`a = 1/2(k/2), where k is the parameter received in the IE "Filter coefficient".
`if k is set to 0 that will mean no layer 3 filtering.
`NOTE:
`In order to initialise the averaging filter, F0 is set to M1 when the first measurement result from the physical
`layer measurement is received.
`The physical layer measurement results are sampled once every measurement period. The measurement period
`and the accuracy for a certain measurement is defined in [19] and [20].
`Table 8.6.7.2 lists for all measurement quantities and reporting quantities if L3-filtering is applicable or not and
`used L3-filtering type for each measurement quantity.
`Table 8.6.7.2: L3 filtering applicable for each measurement quantity and reporting quantity
`Measurement- / Reporting
`L3-filtering
`Comment
`quantity
`applicable
`Yes
`No
`
`Linear or
`logarithmic filtering
`Log
`-
`
`
`
`
`Pathloss
`Cell synchronisation
`information
`Cell Identity
`Frequency quality estimate
`
`No
`No
`
`-
`-
`
`
`Although the frequency
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`HTC/ZTE Exhibit 1004-3
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`quality estimate itself is
`not filtered, the inputs
`to the frequency quality
`estimate calculation
`(CPICH Ec/N0 or
`CPICH RSCP or P-
`CCPCH RSCP) are
`filtered
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Log
`Log
`Log
`
`-
`Log
`Log
`
`Log
`-
`Log
`-
`-
`
`
`The UE shall support 2 different layer 3 filters per measurement type defined in subclause 8.4.0 (i.e. the UE shall
`be capable to apply at least 2 different L3 filters to intra-frequency measurement results, at least 2 different L3
`filters to inter-frequency measurement results, etc.). If a MEASUREMENT CONTROL message is received that
`would require the UE to configure more than 2 different layer 3 filters, the UE may:
`1> set the variable CONFIGURATION_INCOMPLETE to TRUE.
`
`UTRA carrier RSSI
`GSM carrier RSSI
`UE transmitted power
`FDD
`> UE Rx-Tx time difference
`> CPICH Ec/N0
`> CPICH RSCP
`TDD
`> Primary CCPCH RSCP
`> Proposed TGSN
`> Timeslot ISCP
`> TADV (1.28 Mcps TDD)
`> Applied TA (3.84 Mcps TDD)
`
`Yes
`Yes
`Yes
`
`No
`Yes
`Yes
`
`Yes
`No
`Yes
`No
`No
`
`
`
`------------- Omitted text -------------
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`HTC/ZTE Exhibit 1004-4
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