1、 Report ITU-R M.2115-1(12/2009)Testing procedures for implementation of dynamic frequency selectionM SeriesMobile, radiodetermination, amateurand related satellites servicesii Rep. ITU-R M.2115-1 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and e
2、conomical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed
3、 by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be
4、 used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found.
5、 Series of ITU-R Reports (Also available online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermina
6、tion, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This
7、ITU-R Report was approved in English by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2010 ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R M.2115-1
8、 1 REPORT ITU-R M.2115-1 Testing procedures for implementation of dynamic frequency selection (2007-2009) 1 Introduction Resolution 229 (WRC-03) invites the ITU-R to undertake studies on suitable test methods and procedures for the implementation of dynamic frequency selection (DFS), taking into acc
9、ount practical experience. Currently several administrations and/or standards organizations have developed DFS test methodology. This Report consolidates the DFS test methodology used and findings across several administrations, as shown in several annexes. Information is provided on the test method
10、ologies in place in various administrations and/or regional groups to test compliance with DFS requirements. These procedures may be updated over time, and as technology evolves. As a result, web links are provided (in some cases) to the test methodologies themselves, so that the most up-to-date inf
11、ormation may be obtained. 2 Background The DFS requirements mandated by Resolution 229 (WRC-03) contained in Recommendation ITU-R M.1652 Annex 1 are broken down into three functional areas: detection requirements; operational requirements; response requirements. From a spectrum management view point
12、, testing for these requirements are quite different than the normal field strength or power flux density requirements and a clear description of the methods and process for testing will ease manufacturers ability to show compliance with the administrations rules. Conformance testing provides a mean
13、s to analyse equipment operations against set functional requirements prior to authorization of devices within an administration. To successfully develop conformance test procedures certain descriptions are required to enable manufacturers to develop equipment that will meet or exceed administration
14、 requirements. 3 Equipment setup The test procedures for implementation of DFS in the 5 250-5 350 MHz and 5 470-5 725 MHz bands should include a full description of the equipment used to transmit test waveforms and monitor DFS reactions as prescribed in Recommendation ITU-R M.1652. 2 Rep. ITU-R M.21
15、15-1 4 Test methodology The test procedures for implementation of DFS in the 5 250-5 350 MHz and 5 470-5 725 MHz bands should also include a comprehensive description of the test methodology used for compliance. This should have at a minimum the waveforms to be tested and procedures to be followed d
16、uring testing. 5 Detection requirements There should be a clearly defined detection requirement for each test waveform utilized to ensure that manufacturers and test facilities have a clear understanding of the metric to be applied to each. If multiple requirements will be placed on a data set (i.e.
17、 individual waveform detection requirement with an overall group of waveforms having an additional requirement) these should also be clearly defined. Annex 1 Japan 1 Background In Japan, technical compatibility requirement, including the frequency sharing study and measurement procedures are address
18、ed by the committee formed by the Information and Communications Council (hereinafter “Council”). With regard to RLAN devices in the 5 GHz band, the Council has set up a technical committee on wireless access systems in the 5 GHz band which has undertaken the role of studying technical requirements
19、for such RLAN devices. Based on the Council Report, MIC (Ministry of Internal Affairs and Communications) regulates technical requirements to facilitate development of type acceptance testing procedures. 2 Scope DFS requirements were institutionalized in the 5 250-5 350 MHz band in May 2005 and 5 47
20、0-5 725 MHz band in January 2007. On the same day, the notification of WAS test procedure was published. The Association of Radio Industries and Businesses (ARIB the private standards organization in Japan) published the revision of ARIB Standard T-71 based on IEEE 802.11 CSMA/CA standards and incor
21、porates regulatory requirements including DFS functionality in Japan. DFS requirements in Japan are composed of those given in Recommendation ITU-R M.1652 Annex 1, harmonized international requirements and those for protecting Japans specific radars. 3 Procedures The DFS capability can be verified t
22、hrough the examination of detection probability. It must be repeated many times to obtain accurate test results. It is time consuming and may reflect to the cost impact to WAS devices. Therefore, Japan adopted the method of testing procedures to enable relatively more accurate pass/fail decision und
23、er relatively smaller cycle of testing. These Rep. ITU-R M.2115-1 3 considerations are introduced in following attachment for reference. To achieve further reduction of testing items which conform to DFS function to various kinds of radars, similar radar types are grouped, and random sample testing
24、method within grouped radars was adopted. The latest version of mandated DFS requirements and test procedures in Japan can be obtained from MIC publications Download Area Website (http:/www.tele.soumu.go.jp/e/equ/tech/5ghz.htm). Appendix 1 to Annex 1 An example of DFS test methods and calculation re
25、sult for DFS detection probability This Attachment shows an example of DFS test methods and a calculation result of the probability of DFS detection during in-service monitoring. The calculation targets a rotating meteorological radar and WAS devices based on the IEEE 802.11a standard. 1 Parameters
26、in design of DFS test method The following parameters are required to design DFS test methods, because the probability of DFS detection is largely dependent on them: margin to the detection threshold; data traffic; decision threshold by detected pulses. 1.1 Margin to the detection threshold There is
27、 a margin between the detection threshold defined in Recommendation ITU-R M.1652 Annex 1 and the necessary detection threshold described in Recommendation ITU-R M.1652 Annex 5. Therefore the WAS devices can receive the signal above the threshold out of the main beam of radar. For this reason, the an
28、alysis time during in-service monitoring is redefined as the period during which the WAS receives the radar signal above the threshold in one sweep. Consequently, the analysis time is calculated as “2 offset/Scan rate”, where offsetis the off-axis angle and the antenna gain of off-set offsetis below
29、 the peak by the margin. 1.2 Data traffic Step 3 of Recommendation ITU-R M.1652 Annex 4 defines available time for in-service monitoring as only listening periods; however, idle time during which the WAS devices have no transmitting data is also available for in-service monitoring. Since the idle ti
30、me depends on data traffic among the WAS devices, the data traffic is an important factor for the detection probability. It is noted that the data traffic for IEEE 802.11a based devices increases when the packet loss occurs by interference from the radar, because the WAS devices resend the lost pack
31、et instead of idling. 4 Rep. ITU-R M.2115-1 Therefore, the important factor will be the radio-transmitting activity ratio such as Talk/Listen timing, because, recently the chipset companies who have 802.11a function, have implemented enhanced functions such as the large packet mode, the fast burst m
32、ode, etc., and random back-off timing must be considered additionally. 1.3 Decision threshold by detected pulses The WAS devices with typical implementations recognize the radar signal by detecting each pulse rise/fall. Therefore, the number of the pulses received in the available time is a key fact
33、or for the probability of detection. Such devices use a pulse counter to determine radar detection. To avoid false alarm, a number larger than one is set as a decision threshold by detected pulses. 2 Calculation 2.1 Calculation procedure Considering the parameters addressed in the above sections, th
34、e calculation of the DFS detection probability based on the methodology in Recommendation ITU-R M.1652 Annex 4 is demonstrated as follows. Step 1: Determine the number of pulses, Np, received in the analysis time as follows: Np= 2 offset/Scan rate Pulse repetition rate Step 2: For simplicity of calc
35、ulation, since analysis time is usually much longer than the radar pulse repetition period, the probability of detection, Pd, that one radar pulse falls into a listening period during the radar pulse repetition period is set as the average time ratio of the listening periods to the total time. Then,
36、 calculate the probability, P(m), wherein the WAS device detects m pulses within the analysis time as follows: ()mNdmdppPPNmmP= 1)( Step 3: Calculate probability, P(m, Np), wherein the WAS device detects more than m pulses within the analysis time as follows: =10)(1),(mipiPNmP Step 4: Probability of
37、 detection in n rotations: Q : probability of detection in one rotation QS: probability of detection in n rotations ()1),(1),(=nppNmPNmPQ npniNmPQQs ),(1(11= Rep. ITU-R M.2115-1 5 2.2 Calculation example of radar detection probability for a meteorological radar deployed by an administration in Regio
38、n 3 According to the procedure based on Recommendation ITU-R M.1652 Annex 4, the probability of DFS detection for meteorological radar deployed by an administration in Region 31is calculated as the following table: Radar Radar type Antenna horizontal scan type (360) Platform GroundTuning range (MHz)
39、 5 250-5 350 Tx power into antenna peak (kW) 250 Receiver IF3 dB bandwidth (MHz) 1.6 Antenna main beam gain (dBi) 43 Pulse width (s) 2.5 Pulse repetition rate (pps) 260 N = k T B F (dBm) 109 N 6 dB 115 Scan rate (degrees/s) 24 WASe.i.r.p. (dBm) indoor 23 Bandwidth (MHz) 18 DFS threshold for protecti
40、on (TDFS) 64 Necessary detection threshold (dBm) 43.5 (Note 2) Margin to detection threshold (dB) 20.5 Analysis time in one rotation (ms) 192 Np: Number of pulses received within the analysis time 50 Pd (Note 1) 0.3157 Decision threshold by detected pulses (Note 4) 4 Q: Probability of radar detectio
41、n (%) in one rotation 99.999 NOTE 1 This calculation assumes that the data is transmitted between the master device and the client device fully at a data rate of 54 Mbit/s. NOTE 2 The necessary detection threshold is calculated using the method described in Recommendation ITU-R M.1652, Annex 5. NOTE
42、 3 The antenna pattern in Recommendation ITU-R M.1652 Annex 6 is used in this calculation. NOTE 4 Substituted for “m”. 1This radar is planned to be added to Recommendation ITU-R M.1638. 6 Rep. ITU-R M.2115-1 2.3 Example of DFS test method to judge detection ability effectively 2.3.1 Test signal Cons
43、idering testing WAS devices at conformity assessment bodies, it is not practical to measure the radar detection ability using real radar pulses and thousands of trials to show almost 100% radar detection ability. For this reason, the administration adopts test signals and detection probability to th
44、is signal for the purpose of WAS conformance testing. In the case of the meteorological radar shown above, the following test signal and detection probability are used. TABLE 1 Test signal and detection probability for meteorological radar Pulse width (s) Pulse repetition rate (pps) Number of pulses
45、 Detection probability (%) For Meteorological Radar on 2.2 2.5 260 18 60 Figure 1 shows that detecting this test signal at 60% is equivalent to detecting radar approximately 90.2% in the worst case and approximately 99.8% in the best case within the analysis time in one rotation. The test signal det
46、ection probability of 60% can be achieved at Pdof 0.2244 which would be caused by adoption of a lower transmission speed. 2.3.2 Required number of trials to minimize fault pass, fault fail decision and test time consumed The detection probability P(l) is distributed as binomial since it can be consi
47、dered as independent between trials. ()lNlPPNllP= 1)( where: N : number of trials per test for each test signal l : number of detection success trials per test P : radar detection probability of UUT for infinite number of trials. Test success probability Ps can be calculated as accumulated binomial
48、distribution of the above: ()iNiNliNliPPNiiPPs=1)( where: l /N : specified minimum detection ratio, such as 0.6 to 0.7. The relation between radar detection probability of the unit under test (UUT) and test success probability is shown in Fig. 2. Here, the minimum detection ratio is 0.6 and the numb
49、er of trials per test signal is 10, 20, 40 and 100. Table 2 shows the probabilities of fault pass and fault fail. Rep. ITU-R M.2115-1 7 FIGURE 1 Probability of radar detection by a DFS device which can detect test signals of 18 pulses at 60% probability Rep 2115-01No. of radar pulsesQ min: pulse counter reset by every 18 pulsesQ max: pulse counter without reset function 99.9999.999900Radardetectionprobability(%)0 50 100 1508 Rep. ITU-R M.2115-1 FIGURE 2 Radar detection probability P of UUT vs. T
