ERMTGSRR(17)000001r3
Title*: / Assessment and TG SRR answer on EN 302 264 V211from Source*: / WG/TG Chairman
Contact: / Michael Mahler
input forCommittee*: / ERM TGSRR
ContributionFor*: / Decision
Discussion / X
Information
Submission date*: / 2017-06-23
Meeting & Allocation: / -
Relevant WI(s), or deliverable(s):
ABSTRACT:Comment Resolution Proposal EN 302 264 V2.1.1 (2017)
Title:
Short Range Devices; Transport and Traffic Telematics (TTT) - Short Range Radar equipment operating in the 77 GHz to 81 GHz band - Harmonised Standard covering the essential requirements of article 3.2 of Directive 2014/53/EU
Former work item: REN/ERM-TGSRR-76 -
ETSI received comments from EC desk officer @ 19th of June 2017
The comments were made available in ETSI (TC ERM)
Link to the document: ERM(17)062085_Comments_from_the_European_Commission_on_EN_302_264_v2_1_1.docx
The received comments are transferred into this document.
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ERMTGSRR(17)000001r3
Item / Clause/ Subclause / COMMENTS / Question / TG SRR assessment / Proposed change / OBSERVATIONSon each comment submitted
2 / 4.2.3 / Why are the scanning/fixed parameters of the antennas not defined in clause 4.2.3? For instance, the definition of the main/side lobes of the antennas or its scan rate (where applicable) can provide requirements for the reduction of interference to devices in the surrounding area. It may then be considered whether this clause provides information on the presumption of conformity and, as such, to be referred to in the Annex A. / There is no scanning requirement in the radio regulation (ECC/DEC(04)03). Therefore, there is currently no need to specify such requirement for article 3.2.
TG SRR has in addition currently no information that scanning devices are on the market and therefore no specific test is necessary.
But TG SRR confirm to contact the stakeholders and will take this point into account for a further revision of EN 303 396 an EN 302 264
TG SRR is aware of possible further requirements to have electronically scanning capability within the 76 – 77GHz and 77 – 81GHz bands. The scanning could be on both TX and RX side.
Use cases exist within autonomous driving scenarios requiring on-demand steering/scanning. / TG SRR proposes to put this point to the shopping list for a further revision of the EN
Item / Clause/ Subclause / COMMENTS / Question / TG SRR assessment / Proposed change / OBSERVATIONS
3 / 4.3.1.3 / In clause 4.3.1.3 it is not clear how this band is measured (-1dBc, -40dBc, -100dBc?). / The 99% rule is related to -23dBc.
TG SRR got the information that measurement equipment has such measurement function (implemented in the e.g. spectrum analysers).
This procedure was also used in the former R&TTE Standards. No difference between R&TTE Version and RE-D version.
But it is generic point for all EN (also for all the EN under TG SRR responsibility) and needs to be reflected in a revision of EN 303 396.
To show the link between 99% and -23dBc (for different kind of current used and possible future modulations) TG SRR started the work on a justification document:
Link to the work item
Based on feedback from test-houses this procedure is well known. For clarification TG SRR will add this additional information in a further revision (after justification, signal related)
Additional information:
for the 99% OBW, this is clearly defined in the ITU Radio Regulations, if we choose beta=1% (standard value for most spectrum analysers)
Radio Regulation Version 2016:
RR 1.153 occupied bandwidth: The width of a frequency band such that, below the lower and above the upper frequency limits, the mean powers emitted are each equal to a specified
percentage β/2 of the total mean power of a given emission.
Unless otherwise specified in an ITU-R Recommendation for the appropriate class of emission, the value of β/2 should be taken as 0.5%.
and in ITU R-REC-SM.329 are the basis for the out-of-band and spurious domain / Based on feedback from test houses this procedure is well known.
For clarification TG SRR will add this additional information in a further revision (including justification, signal related).
In future (new signal modulations) an amendment in the definition could be necessary as well. But therefore a ETSI coordination is necessary.
Item / Clause/ Subclause / COMMENTS / Question / TG SRR assessment / Proposed change / OBSERVATIONS
4 / 4.3.1.4 / Clause 4.3.1.4 worsens of a factor 100 the measurement uncertainty of the previous version of this standard. / For the high frequencies currently no assessment/justification for MU was done (by ETSI).
The value which is used is based on information from stakeholders and test-houses.
To be correct: TG SRR started the work to evaluate the MU within these ranges:
Link to the work item
Based on the current situation (frequency users) TG SRR has the view that the current limit is sufficient.
A first technical assessment:
The typical frequency accuracy on an automotive SRD is in the order of around 100ppm (determined by the quartz crystal)
This is also specified by FCC " (...The frequency tolerance of the carrier signal shall be maintained within 0.01% of the operating frequency over a
temperature variation of -20 degrees to + 50 degrees C at normal supply voltage, and for a variation in the primary supply voltage from 85% to 115% of the rated supply voltage at a temperature of 20 degrees C...)
0.01% =100ppm
The specified accuracy in EN 303 396 for the test equipment is 10ppm and therefore 10x more accurate compared to equipment-under-test
/ No urgent change necessary
But:
After evaluation MU this will be reflected in the necessary documentation.
TG SRR recognized that MU is a general point under discussion between (EC and ETSI).
Question: shall MU part of a harmonized EN (as a requirement)
5 / 7.1.3.2 / Clause 7.1.3.2 of the EN 302 264-1 v1.1.1 specifies the method of measurement of the power (spectrum analyser with detector in max-hold mode). In this version this appears to be removed. As a consequence, there is ambiguity on how to measure this parameter. / This point was discussed in TG SRR during the preparation of all ENs dealing with the high frequencies. After consulting also test – houses own tests within the group members it was decided that the performance of the test procedure is not correct (for the kind of signals) and therefore it was decided to delete. / No action necessary.
Test procedure are state of the art and correct the TX-signals used by the devices.
6 / Table 4 / The requirements in Table4 in bands 790 MHz to 862 MHz worsens of 18dB Table 5 of the previous version of this standard. / This is correct. The changes are based on ECC studies (ECC report 261 and 246).
Reason why the limits are possible:
History: in the past broadcasting receivers worked in this range
Today: IMT (LTE) equipment (second digital dividend).
Therefore, the users changed in this range and from TG SRR view there is no need to fulfil such stringent protection requirement.
TG SRR expect that the changes will be reflected in the currently started revision of ERC REC 74-01.
In addition, TG SRR would like to note that emission in this range are very unlikely based on the TX- signal. The emissions in this range are mainly based on other effects (EMC of digital parts) Therefore it shall be taken into account that the EMC requirement is more relaxed: -30dBm/MHz. / No action necessary because on the protection requirement of the new frequency users
Action for ETSI:
To follow the revision of ERC REC 74-01 that the new requirements (result of studies) will be implemented
7 / 4.3.4.3 and
4.2.1.4 / F1 and F2 in clause 4.3.4.3 worsen those in clause 4.2.1.4 of EN 302 264-2 v1.1.1. / Note: Details below.
In Version 1.1.1 out of band domain and spurious domain was covered by one clause. In 2.1.1 separated in two. This is requested by the ETSI guide / No action necessary: limits are the same.
8 / 4.2.2.1; Table 5 / Table 5 worsens the limits in clause 4.2.2.1 of EN 302 264-2 v1.1.1 (eirp vs erp in frequencies below 1 GHz). / Yes it is correct that there is a change from e.i.r.p to e.r.p..
The EN follows the state of the art below 1GHz the reference is erp and above eirp. This is mainly related to the measurement antennas.
In addition, it shall be taken into account that
- there is a range of min 76GHz and therefore the emissions of the RX below 1GHz is not the major part.
- TX and RX is co-located in any kind of the devices and TX spurious are more relaxed.
- Digital unit emissions (EMC) are: -30dBm/MHz
RR1.161 equivalent isotropically radiated power (e.i.r.p.): The product of the power supplied to the antenna and the antenna gain in a given direction relative to an isotropic antenna (absolute or isotropic gain).
RR1.162 effective radiated power (e.r.p.) (in a given direction): The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction. / No action necessary for the EN.
Action for ETSI to inform ECC that this shall be more clear during the revision of ERC REC 74-01
9 / 4.4.3.2 / Clause 4.4.3.2 has general requirements, which provide presumption of conformity. Has the user to establish him/herself how to apply this clause (which gives presumption of conformity)? / This requirement is related to the use-cases for which the sensor was developed. The main requirements are based out of the “request” of the car manufacturer. The car manufacturer would like to realize a “use-case” with the sensor, e.g. to detect a car within 100m max and 10m min. Based on this the sensor manufacturer develops the sensor (with all system parameters), like TX-power, Signal BW, RX, BW, ……
The driver of the vehicle , who is the end user at has no influence on the requirements he will use only the function of the vehicle, like emergency breaking.
10 / 4.4.4 / There is no receiver sensitivity in clause 4.4.4. Please note that receiver parameters are a precise legal requirement. / ETSI has the view that the new concept is a new kind of RX-requirement (new approve ETSI STF BN, start on 10/2017).
The devices covered by this EN shall be not compared with traditional “RADAR” systems. We shall more say: short range radio determination devices which work on the “radar” principle.
TG SRR discussed this point heavily and the main reasons why the traditional RX-requirements are not practical to measure and to specify:
-Regulation very specific lot of different technical realizations possible.
-Devices are highly integrated and therefore no possibility to a physical connection to get the signal information out of the RF/NF path which would be necessary for e.g. sensitivity measurements.
-Sensor has no user interface, information sensor measurement results are delivered to the “car” system as specific data (on-board unit. Based on the information (object yes, no, number of objects, location of detected objects speed) the function, e.g. emergency breaking will be activated.
-If “classical” RX parameters would have to be tested, specific samples would need to be prepared and presented for testing along with special test software
-Also a high sensitivity would not directly lead to a “´high efficient spectrum usage”. The sensitivity shall be taken based on the interfering situation and the “measurement situation (object, distance, speed)
Therefore TG SRR has the view that based on the RE_D requirement “spectrum efficient use” it is better to test the function of the device indirectly the RX instead to fix some values.
But TG SRR agrees that there are possibilities to amend the test but therefore more time is necessary based on the different kind of technical solutions for the same use-case (under the same radio regulation)
This view is summarized in following document:
/ The new Interferer signal handling concept is a usable solution for some kind of devices (e.g. radio determination, UWB,..) to get information on the usage based on possible interferer.
TG SRR started therefore additional evaluation / justification (new TS).
In addition, TG SRR supports the work of the approved ETSI STF for the interferer signal handling RX-concept.
If there are more devices in the market interference situation will change and ETSI will take this evolution into account during the work on the TS and ETSI STF.
The STF BN (“interferer signal handling”) was approved and work will start 10/2017, currently call for experts
11 / 4.4.4 / In the same clause, I would expect that the receiver requirements for Doppler radars, imaging radars or detection radars are well defined. Please note that receiver parameters are a precise legal requirement. / See comments above
But for TG SRR the differences mentioned are not clear.
Each sensor based on the radar principal is able to get information on: speed / frequency shift (Doppler), time delay (RX/reference) = distance, S/N = RCS of the object = kind of object.
The RX requirements are more dependent on: kind of object (incl. numbers) shall be detected in a given distance. use-case (inclusive sensor combinations)
12 / As a radar, there is no noise figure, which is another key receiver parameter of radars. Please note that receiver parameters are a precise legal requirement. / See comments above
Note: please not compare “radar” from the traditional view (airports, ships,…) with “short range devices” based on the radar concept/principal / TG SRR shall change the title of the EN (within a further revision) to avoid misunderstanding.
13 / 4.5.1.2 / With respect to Clause 4.5.1.2, whois responsible for changes when the product is notstand-alone? / At the end the device manufacturer because he is selling the device to the car manufacturer device will be placed into the market.
The requirement in clause 4.5.1.2 is dependent on the installation situation of the radar sensor on a specific vehicle platform.
The radar sensor manufacturer provides detailed instructions to the vehicle manufacturer regarding installation of the radar sensor on a specific vehicle platform
The installation requirements / instructions for the same radar sensor might differ between different vehicle platforms
The radar sensor is mounted during production of the vehicle, no end-user modification possible afterwards.
Radar-sensor is no retrofit part, that can be applied after manufacturing of the vehicle.
The intended use of the sensor requires certain initial arrangements that cannot be introduced after the vehicle was produced
14 / 4.5.1.4 / Clause 4.5.1.4 does not appear to be lawful. I will pass it to colleagues for an internal legal advice.
15 / 5, 6 and 7 / Clauses 5, 6 and 7 are not clear when they mention "as varied herein". How does this wording provides to users of this standard clear instructions or requirements? / This sentence/wording is used in a lot of other EN as well. The meaning is:
The reference applies completely if there are no other points/differences/variations mentioned within this specific clause.
EN 303 396 was finalized and published before EN 302 264 started the ENAP procedure and therefore EN 303 396 was fixed.
Feedback from test – houses: wording is clear / From our point of view no action necessary
Comparison / EN 302 264 V1.1.1 / EN 302 264 V2.1.1 / Summary / Comments
For Item 7 / 4.2.1.2 refers too
The effective radiated power of any spurious and out-of-band emissions shall not exceed the limits specified in
clause 7.2.4 of EN 302 264-1 [1].
In clause 7.2.4 of EN 302 264-1 V1.1.1
Following limits are listed
Table 4: Limits of radiated spurious emissions
Frequency range / Limit values for spurious radiation
47 MHz to 74 MHz / -54dBm
87,5 MHz to 118 MHz / -54dBm
174 MHz to 230 MHz / -54dBm
470 MHz to 862 MHz / -54dBm
otherwise in band 30 MHz to 1000 MHz / -36dBm
1000 MHz to 100 GHz (see note) / -30dBm
NOTE:Not applicable within the permitted range of frequencies for the 79GHz SRR from 77 GHz to 81 GHz.
Table 5: Limits of radiated out-of-band emissions
Frequency range / Limit values for out of band radiation
25 GHz to 77 GHz / -30dBm/MHz
81 GHz to 100 GHz / -30dBm/MHz
/ In 4.3.4 out of band domain
The values fLand fHare the results of the operating frequency range conformance test, see clause 4.3.1.4.
The values F1 and F2 are calculated as in ETSI EN 303 396 [1], clause 6.2.11
In 4.3.5 spurious domain
/ Note: the calculation of F1 and F2 is based on the calculation (which is used in quasi all EN) 250% of the TX-Signal-BW below and above the centre frequency of the TX-signal.
Therefore, this requirement is no in line with the radio definition of the out – of – band and spurious domain. (for non UWB signals)
In addition, the limits below F1 and above F2 is equal to the Version 1.1.1. --> -30dBm/MHz
This range is in Version 2.1.1 the spurious domain requirement in clause 4.3.5
Additional note: this 250% rule is also part of ERC REC 74-01!
Basis for this requirement:
Recommendation ITU-R SM.329
And
Recommendation ITU-R SM.1539
For item 8 / In clause 8.1.3 of EN 302 264-1 V1.1.1
The maximum equivalent isotropic radiated power (max. e.i.r.p.) of any spurious emission outside the permitted range of frequencies, shall not exceed 2nW (-57dBm) in the frequency range 25MHzf1GHz and shall not exceed 20nW (-47dBm) on frequencies above 1 GHz. /
Excerpt ERC REC 74-01
Receivers and idle/standby transmitters / -57 dBm, for 9 kHz f 1GHz
-47 dBm, for 1 G FPPER
(see recommend 11)
/ In ERC REC 74-01 no detector type or the reference (erp or eirp) is specified only the measurement BW and the range (based on the harmonics) the measurement shall be performed.
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