ETSI TS 102 754 V1.3.1 (2013-03)

Technical Specification
Electromagnetic compatibility
and Radio spectrum Matters (ERM);
Short Range Devices (SRD);
Technical characteristics of Detect And Avoid (DAA)
mitigation techniques for SRD equipment using
Ultra Wideband (UWB) technology

2 ETSI TS 102 754 V1.3.1 (2013-03)

Reference
RTS/ERM-TGUWB-019
Keywords
radar, radio, SRD, UWB
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ETSI
3 ETSI TS 102 754 V1.3.1 (2013-03)
Contents
Intellectual Property Rights . 5
Foreword . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions, symbols and abbreviations . 7
3.1 Definitions . 7
3.2 Symbols . 7
3.3 Abbreviations . 8
4 User defined clause(s) from here onwards . 8
4.1 User defined subdivisions of clause(s) from here onwards . 8
4.2 Zone model . 8
4.3 Detect and Avoid operational flow . 10
4.4 Applicable frequency ranges . 11
4.5 DAA operational modes . 12
5 Detect framework . 12
5.1 Introduction . 12
5.2 Detect options . 12
5.2.1 Measurement of received victim signal strength . 12
5.2.2 Processing of available external victim service information . 14
5.2.3 Combination of both . 15
5.3 Detection parameters . 16
5.3.1 Initial Channel availability check time . 16
5.3.2 Maximum Detect and Avoid time, t . 17
avoid
5.3.3 Signal detection threshold, D . 17
thresh
5.3.4 Detection probability . 17
6 Avoidance options . 17
6.1 Introduction . 17
6.2 Transmit power management . 18
6.3 Band relocation . 18
6.4 Frequency band notching . 18
6.5 LDC . 18
6.6 Antenna techniques . 18
6.7 Combinations . 18
6.8 Avoidance parameters . 18
6.8.1 Minimum avoidance bandwidth . 18
6.8.2 Default Avoidance bandwidth . 19
6.8.3 Maximum avoidance power level . 19
6.9 Switching to LDC . 19
7 Test considerations . 19
7.1 General considerations . 19
7.2 Considerations for radio location services . 20
7.3 Considerations for BWA services . 20
7.4 Maximum allowable measurement uncertainty . 20
Annex A (normative): Radio location services in the band 3,1 GHz to 3,4 GHz . 21
Annex B (normative): Broadband wireless access services in the band 3,4 GHz to 3,8 GHz . 22
Annex C (normative): Radio location services in the band 8,5 GHz to 9,0 GHz . 23
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4 ETSI TS 102 754 V1.3.1 (2013-03)
Annex D (normative): DAA Test Procedure for Radiolocation Services . 24
D.1 Introduction . 24
D.2 Initial Start-up test . 24
D.2.1 Test without a radiolocation test signal during the Minimum Initial Channel Availability Check Time,
T . 24
avail_time_min
D.2.2 Tests with a radiolocation test signal at the beginning of the Minimum Initial Channel Availability
Check Time, T . 25
avail_time_min
D.2.3 Tests with radiolocation test signal at the end of the Minimum Initial Channel Availability Check Time,
T . 27
avail_time_min
D.3 In-operation test . 29
D.3.1 In-operation test procedure . 29
D.4 Test patterns for the radiolocation DAA test . 30
Annex E (normative): DAA Test Procedure for BWA systems in the 3,4 GHz to 3,8 GHz
band . 32
E.1 Introduction . 32
E.1.1 UWB radio devices with and without victim service identification . 32
E.2 Initial start-up test . 32
E.2.1 Test without a BWA test signal during the Minimum Initial Channel Availability Check Time,
T . 32
avail_time_min
E.2.2 Tests with a BWA test signal at the beginning of the Minimum Initial Channel Availability Check Time,
T . 33
avail_time
E.2.3 Tests with a BWA test signal at the end of the Minimum Initial Channel Availability Check Time,
T . 35
avail_time
E.3 In-operation test . 36
E.4 Test Patterns for BWA Testing . 37
Annex F (informative): Detection threshold and range . 39
Annex G (informative): DAA Test setup examples . 40
Annex H (informative): Bibliography . 42
History . 43

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5 ETSI TS 102 754 V1.3.1 (2013-03)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Electromagnetic compatibility and
Radio spectrum Matters (ERM).
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6 ETSI TS 102 754 V1.3.1 (2013-03)
1 Scope
The present document provides the technical specifications of Detect And Avoid (DAA) mitigation techniques. These
techniques are focused on the protection of active radio services.
The following DAA mechanisms have been identified to protect the:
• radio location services in the band 3,1 GHz to 3,4 GHz;
• broadband wireless access services in the band 3,4 GHz to 3,8 GHz;
• radio location services in the band 8,5 GHz to 9,0 GHz.
NOTE: The DAA mitigation techniques are to some extent generic and may also be used with modifications for
the protection of other radio services in the future if the technical requirements are identified. The
proposed methods can be deployed by all kinds of Ultra WideBand (UWB) based applications and can be
extended to other radio technologies.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
[1] ETSI TS 102 883 (V1.1.1) (2012-08): "Electromagnetic compatibility and Radio spectrum Matters
(ERM); Short Range Devices (SRD) using Ultra Wide Band (UWB); Measurement Techniques".
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ECC DEC(06)04: "ECC Decision of 24 March 2006 on the harmonised conditions for devices
using UWB technology in bands below 10.6 GHz; amended 9 December 2011".
[i.2] ECC Report 120 (March 2008): "ECC Report on Technical requirements for UWB DAA (Detect
and avoid) devices to ensure the protection of radiolocation in the bands 3.1-3.4 GHz and
8.5-9 GHz and BWA terminals in the band 3.4-4.2 GHz".
[i.3] ECC TG3#18-18R0: "Flexible DAA mechanism based on "isolation criteria" between victim
service and UWB devices", ECC TG3 Meeting 18, Mainz, March 2007.
[i.4] Void.
[i.5] Void.
[i.6] Void.
[i.7] Void.
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7 ETSI TS 102 754 V1.3.1 (2013-03)
[i.8] Void.
[i.9] Void.
[i.10] Void.
[i.11] Recommendation ITU-R SM.1754 (2006): "Measurement techniques of ultra-wideband
transmissions".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
avoid implementation time: maximum time taken to adjust to a new TX parameter set following signal level
measurement and identification, Parameter: T
avoid impl
avoidance level: maximum amplitude to which the UWB transmit power is set for the relevant protection zone
channel availability check interval: maximum time between two consecutive detect operations, Parameter: T
avail
default avoidance bandwidth: portion of the victim service bandwidth to be protected if no enhanced service
bandwidth identification mechanisms are implemented in the DAA enabled devices
detect and avoid time: time duration between a change of the external RF environmental conditions and adaptation of
the corresponding UWB operational parameters
detection probability: probability that the DAA enabled UWB device reacts appropriately to a signal detection
threshold crossing within the detect and avoid time
in operation channel availability check time: minimum time the UWB device spends searching for victim signals
during normal operation, Parameter: T
in op avail
maximum avoidance power level: UWB transmit power assuring the equivalent protection of the victim service
minimum avoidance bandwidth: portion of the victim service bandwidth requiring protection
minimum initial channel availability check time: minimum time the UWB device spends searching for victim signals
after power on, Parameter: T
avail, Time
Non-Interference mode operation (NIM): operational mode that allows the use of the radio spectrum on a
non-interference basis without active mitigation techniques
signal detection threshold: amplitude of the victim signal which defines the transition between adjacent protection
zones, Parameter: D
thresh
signal detection threshold set: set of amplitudes of the victim signal which defines the transition between adjacent
protection zones
victim signal: signal(s) of the service to be detected and protected by the DAA mitigation technique
3.2 Symbols
For the purposes of the present document, the following symbols apply:
T time
f frequency
D detection threshold
I Isolation in dB
P Power in dBm
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8 ETSI TS 102 754 V1.3.1 (2013-03)
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
BPSK Binary Phase Shift Keying
BW Bandwidth
BWA Broadband Wireless Access
CEPT European Conference of Postal and Telecommunications Administrations
CON Condition
CPC Cognitive Pilot Channels
DAA Detect And Avoid
dBm Power emission relative to 1 mW
DFS Dynamic Frequency Selection
DUT Device Under Test
e.i.r.p. equivalent isotropically radiated power
ECC Electronic Communications Committee
EIRP Effective Isotropic Radiated Power
ERM Electromagnetic compatibility and Radio spectrum Matters
FDD Frequency Division Duplex
ICS Implementation Conformance Statement
LDC Low Duty Cycle
LFM Linear Frequency Modulation
LNA Low Noise Amplifier
NIM Non Interference Mode
OFDMA Orthogonal Frequency Division Multiple Access
PPB Pulses Per Burst
PRF Pulse Repetition Frequency
QPSK Quadrature Phase Shift Keying
RF Radio Frequency
RQ Requirement
SRD Short Range Device
TDD Time Division Duplex
TPC Transmit Power Control
TX Transmitter
UL Uplink
UUT Unit Under Test
UWB Ultra WideBand
WLAN Wireless Local Area Network
4 User defined clause(s) from here onwards
4.1 User defined subdivisions of clause(s) from here onwards
The present clause defines a Detect And Avoid (DAA) based interference mitigation architecture for UWB devices to
protect active victim services. In the following clauses the basis for and the individual DAA parameters for protection
of specific services will be given.
4.2 Zone model
The flexible DAA concept is based on the definition of different zones for which an appropriate UWB emission power
level is authorized. Each zone corresponds to a minimum isolation between the potential victim system and the potential
UWB interferer. Based on the minimum isolation an equivalent degree (see note below) of victim service protection is
derived. This concept is embodied in the zone model.
As existing systems are subject to technological change and other systems may be deployed or developed in the future
e.g. IMT-Advanced, it should be noted that different zone parameters and transmission levels may be required.
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9 ETSI TS 102 754 V1.3.1 (2013-03)
The zone model is based on the isolation between the victim device and the UWB device. By deriving the distances
based on the isolation it is possible to segment the region of space around the victim receiver into discrete zones. In the
first zone, zone 1, the UWB device shall operate in the non-interference mode (NIM) as defined in the non DAA
regulatory framework [i.1] using the parameters give in table 1. In the last zone, zone N, the UWB device can operate
without restrictions up to the maximum permitted power level of -41,3 dBm/MHz or as defined in a future DAA
regulation for the corresponding operational frequency range. Between the zone 1 and zone N an arbitrary number of
transition zones 2 to N-1 may be defined, provided equivalent protection can be assured. Based on the result of the
detection process (clause 5) the UWB device has to determine the corresponding zone it occupies.
Table 1: Non-interference mode parameters in the band 3,1 GHz to 9,0 GHz
Operational Frequency NIM Power levels (e.i.r.p.) NIM Power levels (e.i.r.p.) with LDC implemented
-70 dBm/MHz average. -41,3 dBm/MHz average.
3,1 GHz to 3,4 GHz -36 dBm peak 0 dBm peak
(see notes 2 and 3) Standard LDC parameters as in [i.1]
-80 dBm/MHz average. -41,3 dBm/MHz average.
3,4 GHz to 3,8 GHz - 40 dBm peak 0 dBm peak
(see notes 2 and 3) Standard LDC parameters as in [i.1]
-70 dBm/MHz average. -41,3 dBm/MHz average.
3,8 GHz to 4,2 GHz -30 dBm peak 0 dBm peak
(see notes 2 and 3) Standard LDC parameters as in [i.1]
-70 dBm/MHz average. -41,3 dBm/MHz average.
4,2 GHz to 4,8 GHz -30 dBm peak 0 dBm peak
(see notes 2 and 3) Standard LDC parameters as in [i.1]
-41,3 dBm/MHz average. -41,3 dBm/MHz average.
6,0 GHz to 8,5 GHz 0 dBm peak 0 dBm peak
(see note 2) Standard LDC parameters as in [i.1]
-65 dBm/MHz average. -41,3 dBm/MHz average.
8,5 GHz to 9,0 GHz -25 dBm peak 0 dBm peak
(see notes 2 and 3) Standard LDC parameters as in [i.1]
NOTE 1: As defined in the scope of the present document, the DAA mitigation only affects the frequency bands 3,1 GHz
to 3,4 GHz, 3,4 GHz to 3,8 GHz and 8,5 GHz to 9 GHz. NIM power levels for the other frequency bands are
included in this table for informative purposes.
NOTE 2: Devices installed in road or rail vehicle not using LDC need to implement TPC as defined in [i.1].
NOTE 3: Devices fitted with DAA mitigation may operate to the maximum permissible limit of -41,3 dBm/MHz average
and 0 dBm peak.
The zone model is illustrated in figure 1 for N = 4. This example has been taken from the CEPT ECC TG3 regulatory
discussion [i.3]. The transition zones in this example are defined based on a 10 dB pathloss step size.

D
thres_1
D
thres_( N-1)
N = �
�
> 74 dB
65 dB
3,5 m
�
to
55 dB 74 dB
�
to
Victim 45 dB
65 dB
to
1 m
55 dB
9,5 m
31 m
Figure 1: Zone model segmentation and corresponding path loss
with LoS distance in meters for N = 4
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10 ETSI TS 102 754 V1.3.1 (2013-03)
4.3 Detect and Avoid operational flow
The defined zone model is incorporated into the overall detect and avoid operational flow. This flow is depicted in
figure 2.
UWB Device
Power ON
UWB Operation in
Non-Interference (NI) mode
Yes
Stay in
NI mode?
Detect and Avoid time
No
“ ”
Detect operation
Victim Victim
Signal > D Signal < D
thresh_1 thresh (N-1)
Victim Signal
Level estimation
D < Victim < D
2 1
thresh thresh
Signal
UWB Operation in
UWB Operation in UWB Operation in
. . .
Zone 2 N
Zone 1 Zone
Figure 2: Detect and Avoid overview, including N zones
All UWB devices enter a non-interference mode at start-up. This non-interference mode can only be changed after a
signal detect, estimation and decision process has been performed. Estimations are done against threshold levels
D , n = 1…N-1.
thres_n
The non-interference mode operational zone can be subdivided into zones of equivalent protection where appropriate
avoidance techniques are implemented. This gives rise to additional operational zones between the non-interference and
free mode operational zones based on technical considerations. This multi zone concept is illustrated in figure 3 taking
into account the reduction of the UWB transmit power after the application of the appropriate avoidance technique.
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11 ETSI TS 102 754 V1.3.1 (2013-03)
P
uwb_free
Detection threshold D
thresh_N
LoS assumption:
P * [R/R ]
uwb_free N-1
P
uwb_NIM
Distance from Victim
Victim
R R R R
Range
N-4 N-3 N-2 N-1
Basic zone model
Zone 1    Zone N, N=2
E.g. 5 zone model
Zone 1    2 3 4 Zone N, N=5

Figure 3: Illustration of multi zone concept based on equivalent protection levels
The basic zone model consists of two zones, the non-interference mode operational zone, zone 1, and the free mode
operational zone, zone N, N = 2. The basic threshold level D , separating free mode operational zone and the
thresh_(N-1)
non-interference mode operational zone, is defined by two key parameters:
• Minimum needed isolation I, including margins for an interference free operation of the victim receiver, when
in the presence of a UWB device operating in zone N.
• The transmit power of the victim device P .
TX_vic
Then D is given as:
thresh_(N-1)
D = P – I
thresh_(N-1) TX_vic
During the detection and estimation process performed by the UWB device, a received victim signal level will be
compared to the threshold level D . If the received victim signal level exceeds the threshold level D
thresh_(N-1) thresh_(N-1)
the UWB device shall operate in the non-interference mode. This signal level estimation is periodically updated in order
to accommodate the potential changing RF environmental conditions. When changes in the RF conditions are detected
the operational mode of the UWB device shall be adapted accordingly.
4.4 Applicable frequency ranges
The required UWB operational frequencies are defined by the victim services. For the purposes of the present document
the measurements are made at the -10 dBc [i.11] points.
The operational frequency bands required are given in table 2. The UWB system bandwidth as defined by the
-10 dBc [i.11] points shall at least partly include the victim service. Where the frequency span of the UWB radio device
is insufficient to cover the victim service's bandwidth, the frequency range shall be split into two bands and tests
repeated for the higher and lower frequency ranges.
ETSI
Power
12 ETSI TS 102 754 V1.3.1 (2013-03)
Table 2: UWB System bandwidth for test
Victim Service Bandwidth Comments
S-band Radiolocation 3,1 GHz to 3,4 GHz NIM power level:
- -70 dBm/MHz mean
- -36 dBm peak in 50 MHz
BWA 3,4 GHz to 3,8 GHz NIM power level:
- -80 dBm/MHz mean
- -40 dBm in 50 MHz peak
X-Band Radiolocation 8,5 GHz to 9 GHz NIM power level:
- -65 dBm/MHz mean
- -25 dBm in 50 MHz peak
4.5 DAA operational modes
To assure the repeatability of tests it will be necessary to ensure that all UWB radio devices under test follow a
predefined start up and enter a known status following the start up. The condition at the end of the start up shall be
dependent upon the test being undertaken. The suggested status is given in table 3.
Table 3: UWB radio device status during test
Test ID UWB Status after start-up Comments
TD_Radar_001 & BWA_006 NIM operation: The UWB DAA radio device should be
- LDC set into a operational state where it
- NIM power level intend to operate in a non NIM
operation after the Minimum Initial
Channel Availability Check Time
TD_Radar_002, 003 and BWA_007, 008 NIM operation: The UWB DAA radio device should be
- LDC set into a operational state where it
- NIM power level intend to operate in a non NIM
operation after the Minimum Initial
Channel Availability Check Time
TD_Radar_005 and TD_BWA_009 Transmitting/Receiving data at Payload shall be 50 %
Payload levels identified in the For a two zone system, the max mean
relevant test section at max power level will normally be
permitted mean power level -41,3 dBm/MHz

5 Detect framework
5.1 Introduction
The clause introduces the detection options and victim service related detection parameters for the definition of the
DAA test specification requirements. The limits for the test are given in the victim service related annexes A to C and
are determined in the relevant ECC deliverable [i.2].
5.2 Detect options
5.2.1 Measurement of received victim signal strength
The approach of the measurement of the received victim signal strength is depicted in figure 4. The reliability of the
decision process in comparing the zone thresholds with the measured victim signals shall depend on the type of signal
measured and the signal to noise level of the measurement. The signal to noise ratios achievable by the UWB devices
will be dependent upon the manufacturers' implementation.
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13 ETSI TS 102 754 V1.3.1 (2013-03)
The frequency band selection shall take into account the operational frequency band of the UWB device and all
potential victim services. For convenience this frequency band may be segmented to enhance both characterization and
measurement procedure of amplitudes. Where any amplitudes are detected which are higher than the background noise
of the receiver/measurement subsystem these shall be characterized.
If no signals are detected above the background noise no additional steps have to be taken. This implies that the
minimum usable sensitivity (including a specified blocking capability) of the detector shall allow measurement of DAA
threshold values. Regarding figure 4, i.e. the noise figure of the equipment shall not impair the detection capability of
the DAA mechanism.
The process of characterization shall include not only the identification of the parameters of the received signals but
also the comparison against a known and specified set of parameter (e.g. a pattern) of the potential victim services in the
relevant frequency band. The details on how the characterization is performed will be left to the individual UWB
implementation design. The more comprehensive the characterization information is, the better the possible match with
the avoidance techniques and hence the higher the spectrum efficiency will be.
If none of the detected signals correspond to a potential victim service no further action is needed.
If at least one signal corresponds to a potential victim service, the relevant threshold sets of the zone model shall be
selected. In the following step the members of the relevant threshold sets shall be compared to the corresponding
characterized signal levels. Based on this comparison the UWB operational parameters shall be adapted.
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14 ETSI TS 102 754 V1.3.1 (2013-03)

Start of Detect
Select frequency band for the measurement
Measure amplitude(s) within a given time
no
Is the amplitude(s) higher
than my noise level?
yes: Signal detected
Characterise signal(s)
no
Victim Service(s)
detected?
yes
Select the relevant threshold set(s) D
thresh
Compare signal(s) level to the members of the selected set(s) of
thresholds and adapt operating parameters accordingly
Done
Figure 4: Detect flow diagram for victim signal strength measurement
5.2.2 Processing of available external victim service information
An alternative to the measurement approach (depicted in clause 5.2.1) is the use of current DAA information obtained
from other devices or systems within the receive range of the UWB device (e.g. a centralized DAA detector). This
information can be used by the UWB device to set its own DAA parameters for its local environment, e.g. membership
of the peer group.
Received information comprises but is not restricted to:
• victim service information available from peer UWB devices;
• victim service information available on pilot channels, such as Cognitive Pilot Channels (CPC);
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15 ETSI TS 102 754 V1.3.1 (2013-03)
• control information from potential victim systems.
The scope of the information available to any UWB device is dependent on its specific implementation. The use of such
information carries some risk, e.g. in a mobile environment the zone information may be rapidly outdated, under certain
conditions potential victim service may be hidden from peer groups. The maximum distance among UWB devices
processing external victim service information depends on the definition of the applicable zone model and the
maximum distance shall be specified in case of the information originating from peer UWB devices.
The benefits to be accrued in using such information include increased reliability, detection speeds and lower
processing overheads, e.g. information from collocated devices where common control information is shared.
The use of such information is both context specific and time critical.
The approach is depicted in figure 5.

Start of Detect
no
Is received victim related
information available?
yes
Process this information
Adapt operating parameters accordingly
Done
Figure 5: Detect flow diagram for processing of external information
5.2.3 Combination of both
It is expected that systems will use a combination of the local measurements and the available external information. The
operational flow using the combined approach is given in figure 6.
This combined approach will optimize the UWB resource usage, improve detection performance, improve spectrum
efficiency and minimize processing overhead.
This improvement is mainly reached by including the additional external information in the characterization step and
the adaptation step of figure 4. This information flow is depicted in figure 6 by the dotted lines.
The particular implementation of these disparate sets of information will ultimately determine the extent of the possible
improvements.
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16 ETSI TS 102 754 V1.3.1 (2013-03)

Start of Detect
yes
Is received victim
related information
available?
Process this information
no
Is a
no
measurement
nedded?
yes
Select frequency band for the measurement
Measure amplitude(s) within a given
time
Is the amplitude(s)
no
higher than my noise
level?
yes: Signal detected
Characterise signal(s)
no
Victim Service(s)
detected?
yes
Select the relevant threshold set(s) D
thresh
Compare signal(s) level to the members of
the selected set(s) of thresholds
Adapt operating parameters accordingly
Done
Figure 6: Detect flow diagram for the combination of internal measurements
and external information
5.3 Detection parameters
5.3.1 Initial Channel availability check time
The UWB device shall perform victim system monitoring and shall be required to detect any actively operating victim
system signals within a minimum time given by Minimum Initial Channel Availability Check Time, T . During
avail, Time
the Minimum Initial Channel Availability Check Time, the device may operate in the non interference mode (NIM).
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17 ETSI TS 102 754 V1.3.1 (2013-03)
5.3.2 Maximum Detect and Avoid time, t
avoid
Time duration between a change of the external RF environmental conditions and update or adaptation of the
corresponding UWB operational parameters.
The combined detect and avoid time shall include a number of parameters which are not accessible from the physical
layer. These include:
• Channel Availability Check Periodicity: T .
avail, Period
• In Operation Channel Availability Check Time: T .
in op avail, Time
• Avoid Implementation Time: T .
avoid impl
The Detect and Avoid time is depicted in figure 2. The detect and avoid time shall be tested and a functional test will be
specified for this.
5.3.3 Signal detection threshold, D
thresh
The UWB device shall employ a signal detection function that enables it to detect signals from active victim services.
The currently identified services are BWA and radio location.
This function shall be able to detect victim service signals and measure if the power level is above or below the Signal
Detection Threshold, D in any of the relevant frequency bands. This detection threshold is specified at the antenna
thresh
input/connector assuming a 0 dBi antenna gain for each detection operation and may be based on multiple levels.
The signal detection performance will depend upon the type of signal from the victim service as well as the
signal-to-noise ratio when measured at the UWB device. The signal detection shall ultimately determine the detection
probability achievable. An example calculation is shown in annex G.
The signal detection threshold shall be verified and a functional test specified for this parameter.
5.3.4 Detection probability
The detection probability is the probability that the DAA enabled UWB device reacts appropriately to a signal detection
threshold crossing within the maximum detect and avoid time (see also clause 7.4). A minimum number of test runs
shall be specified to express the required detection probability with a specified confidence level.
Where multiple detection thresholds or detection probabilities are defined a test shall be undertaken for each relevant
threshold/probability combination.
6 Avoidance options
6.1 Introduction
The aim of the avoidance process is to protect the victim service receiver while maintaining an operational link with
peer UWB devices.
Following the detection and identification of a victim system the selected avoidance option shall ensure the required
protection level at the victim receiver.
The avoidance options fall into four major categories:
• power reduction;
• spatial avoidance;
• frequency avoidance;
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• time sharing.
Any of these techniques may be used individually or in combination to protect the victim services provided that the
avoidance levels given in the victim service related annexes are met.
The currently qualified techniques for use with UWB devices are given in clauses 6.2 to 6.7, however, other techniques
may be used where equivalent protection can be demonstrated.
6.2 Transmit power management
Transmit power management is the reduction of the UWB transmission power over the complete UWB operational
band to the required level.
6.3 Band relocation
Band relocation is an avoidance technique where the transmit band of the UWB device is relocated in the frequency
domain to eliminate interference with the victim service. This protection may either be done by band shifting or band
switching.
Band shifting is a partial relocation of the active transmission band of the UWB device within the original operational
frequency band whereas band switching means that a new operational frequency band is selected by the UWB device.
6.4 Frequency band notching
Frequency band notching is a frequency dependent transmit power management technique which protects the victim
services frequency band. This technique has the advantage that out-of-victim-band UWB transmissions may be made at
the maximum permitted power for the operational band in use (see also clause 6.8.1).
6.5 LDC
Low duty cycle techniques reduce the total transmitted energy integrated over a period of time. This is achieved by
transmitting at the maximum power for the given frequency band but restricting the transmission in duration.
This technique is an unsynchronized time sharing avoidance method. As a consequence the LDC technique does not
eliminate interference to the victim services but it may reduce the effect of the interference.
6.6 Antenna techniques
Antenna techniques in general rely on the spatial distribution of the transmitted UWB signal. The spatial distribution of
the signal may be controlled by the directivity of the antenna used. Possible examples include: switching, re-orientation,
phased arrays.
6.7 Combinations
In order to achieve the protection criteria and maintain an operational link with peer devices it may be necessary to
combine a number of the avoidance techniques mentioned above.
6.8 Avoidance parameters
6.8.1 Minimum avoidance bandwidth
This is the minimum bandwidth over which the UWB devices shall reduce their transmission power below the
maximum avoidance level. The values for the minimum avoidance bandwidth are given in annexes A to C.
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6.8.2 Default Avoidance bandwidth
This is the default bandwidth for the avoidance operation. This bandwidth has to be protected in the case a DAA
enabled UWB device does not implement an enhanced victim service bandwidth identification mechanism. The values
for the default avoidance bandwidth are given in annexes A to C.
6.8.3 Maximum avoidance power level
The maximum avoidance power level is the UWB transmit power assuring the equivalent protection of the victim
service. In the basic two zone model the maximum avoidance power level is equivalent to the NIM power level given in
table 1. In the multizone model there is be a hierarchy of avoidance power levels associated with each zone where the
lowest maximum avoidance power level in the hierarchy equals the NIM power level.
6.9 Switching to LDC
UWB devices having LDC and DAA implemented and operating in all or part of the frequency band from 3,1 GHz to
4,8 GHz may also switch on the LDC parameter set to avoid interference to BWA services and radio navigation
services as shown in table 4.
Table 4: LDC limits
LDC parameter Value
Maximum Tx on ≤ 5 ms
Minimum Mean Tx off ≥ 38 ms (mean value averaged over one (1) second)
Accumulated minimum Tx off (Σ Tx off) ≥ 950 ms in one (1) second
Maximum accumulated transmission time (Σ Tx on) 18 s in one (1) hour

7 Test considerations
7.1 General considerations
Any test must verify that the UWB device can detect a victim service and react within a specified time. Therefore the
tests must be able to measure the
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