1、 ETSI TR 102 313 V1.1.1 (2004-07)Technical Report Electromagnetic compatibilityand Radio spectrum Matters (ERM);Frequency-agile Generic Short Range Devicesusing Listen-Before-Transmit (LBT);Technical ReportETSI ETSI TR 102 313 V1.1.1 (2004-07) 2 Reference DTR/ERM-TG28-0413 Keywords Radio, Short Rang
2、e, SRD ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice Individual copies of the present documen
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6、roduction in all media. European Telecommunications Standards Institute 2004. All rights reserved. DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTMand the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its M
7、embers. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI ETSI TR 102 313 V1.1.1 (2004-07) 3 Contents Intellectual Property Rights4 Foreword.4 Introduction 4 1 Scope 5 2 References 5 3 Definitions and abbreviations.6 3.1 Definition
8、s6 3.2 Abbreviations .6 4 Technical proposal .6 4.1 Frequency agile techniques 6 4.1.1 Proposed channelization .7 4.1.1.1 Congested channels.7 4.1.1.2 Narrowing of channels 8 4.1.1.3 Turnover of users 8 4.1.1.4 Time multiplexing.8 4.2 LBT principle .8 4.2.1 Minimum transmitter off-time 9 4.2.1.1 Def
9、inition 9 4.2.1.2 Proposed limit .9 4.2.2 Minimum listening time9 4.2.2.1 Definition 9 4.2.2.2 Limit before first initial transmission9 4.2.2.3 Acknowledge transmission .9 4.2.3 Maximum transmitter on-time 10 4.2.3.1 Definition 10 4.2.3.2 Proposed Limit10 4.3 Frequency agility10 4.3.1 Definition10 4
10、.3.2 Proposed limit.10 4.4 Receiver parameters .11 4.4.1 Receiver threshold 11 4.4.1.1 Definition 11 4.4.1.2 Proposed limit .11 4.4.2 Receiver blocking .11 4.4.2.1 Definition 11 4.4.2.2 Proposed Limit11 4.4.3 Receiver selectivity.11 4.5 FHSS with LBT12 4.5.1 Definition12 4.5.2 Proposed limits .12 4.
11、6 FHSS without LBT (faster hopping than clause 4.5) .12 4.7 Transmitter on-/off-slew rate13 4.7.1 Definition13 4.7.2 Proposed limit.13 4.8 Other technical considerations .13 4.8.1 DSSS duty cycle restriction 13 4.8.2 Other types of spread spectrum modulation .13 5 Standards 13 5.1 Regarding EN 300 2
12、20.13 5.2 Receiver classification14 6 Existing applications within 863 MHz to 870 MHz.14 History 15 ETSI ETSI TR 102 313 V1.1.1 (2004-07) 4 Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these
13、 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 u
14、pdates are available on the ETSI Web server (http:/webapp.etsi.org/IPR/home.asp). 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
15、the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI Technical Committee Electromagnetic compatibility and Radio spectrum Matters (ERM). Introduction ETSI ERM at its 21stmeeting in October 2003 had
16、approved a new work item proposal by ERM TG28 for an ETSI Technical Report on the conditions under which new technologies applications could be introduced to SRDs, i.e.the introduction of new techniques and protocols such as dynamic frequency agility, “Listen-Before-Talk“ (LBT), dynamic duty cycle,
17、etc., into the new extended 863 MHz to 870 MHz band and to run the new techniques in parallel with existing duty-cycle limited simplex systems. The ETSI work is made in parallel with an EEC study on compatibility between existing and new proposed systems as the present ERC Recommendation 70-03 2 doe
18、s for example not allow spread spectrum technologies in the existing 868 MHz to 870 MHz band. The result of the ECC study is given in ECC Report 37 4, which showed that most of the ETSI proposed new systems and technologies can be allowed under the condition of a mandatory use of a LBT access protoc
19、ol. Without the LBT protocol spread spectrum and other technologies can only be allowed if the transmitter duty cycle restriction is 0,1 % or less. The present document shows the result of the ETSI study on implementation of LBT technologies with a view to incorporating them into future revisions of
20、 EN 300 220 3 and potentially other standards for Short Range Devices (SRD). ETSI ETSI TR 102 313 V1.1.1 (2004-07) 5 1 Scope The present document aims at providing an overview of the applicability of the Adaptive Frequency Agile (AFA) and Listen Before Transmit (LBT) techniques for use in Short Rang
21、e Devices (SRD). LBT can be used separately or the two techniques may be used together. The use of LBT and AFA are primarily intended as an enhancement for devices employed in the 863 to 870 MHz band and to improve the efficient use of the allocated radio spectrum. Equipment with LBT is not restrict
22、ed to a duty cycle limitation. If LBT is not used a duty cycle shall be applied as specified in ERC Recommendation 70-03 2 Annex 1 according to ECC Report 37 4. The principle may be considered for use in other bands designated for Short Range Devices (SRD). The present document supports the recommen
23、dations given in ECC Report 37 4. 2 References For the purposes of this Technical Report (TR), the following references apply: 1 Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio equipment and telecommunications equipment and the mutual recognition of their c
24、onformity. 2 ERC Recommendation 70-03: “Relating to the use of Short Range Devices (SRD)“. 3 ETSI EN 300 220 (all parts):“Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25 MHz to 1 000 MHz frequency range with power levels
25、 ranging up to 500 mW“. 4 ECC Report 37: “Compatibility of planned SRD applications with currently existing radiocommunication applications in the frequency band 863-870 MHz“. 5 ERC/DEC(01)04 of 12 March 2001 on harmonised frequencies, technical characteristics and exemption from individual licensin
26、g of Non-specific Short Range Devices operating in the frequency bands 868.0 - 868.6 MHz, 868.7 - 869.2 MHz, 869.4 - 869.65 MHz, 869.7 - 870.0 MHz. 6 ERC/DEC(01)09 of 12 March 2001 on harmonised frequencies, technical characteristics and exemption from individual licensing of Short Range Devices use
27、d for Alarms operating in the frequency bands 868.60 - 868.7 MHz, 869.25 - 869.3 MHz, 869.65 - 869.7 MHz. 7 ERC/DEC(01)18 of 12 March 2001 on harmonised frequencies, technical characteristics and exemption from individual licensing of Short Range Devices used for Wireless Audio Applications operatin
28、g in the frequency band 863 - 865 MHz. 8 ERC/DEC(97)06 of 30 June 1997 on the harmonised frequency band to be designated for Social Alarm Systems. 9 ETSI EN 300 440: “Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 1 GHz to
29、 40 GHz frequency range“. 10 ETSI EN 300 328: “Electromagnetic compatibility and Radio spectrum Matters (ERM); Wideband transmission systems; Data transmission equipment operating in the 2,4 GHz ISM band and using wide band modulation techniques; Harmonized EN covering essential requirements under a
30、rticle 3.2 of the R minimum receiver listen -time; maximum transmitter on-time for a single transmit; maximum transmitter on-time for acknowledge transmissions; frequency agility with random frequency selection. A receiver with high blocking performance is necessary to ensure that the receiver can l
31、isten effectively to a channel during high power transmissions at adjacent bands. ETSI ETSI TR 102 313 V1.1.1 (2004-07) 9 For spread spectrum LBT may also be applied. It shall be noted that: FHSS applications using LBT restrict the minimum dwell time. According to ECC Report 37 4, FHSS applications
32、in the band 863 MHz to 870 MHz shall consider a certain minimum number of hop channels to be compatible with existing applications. DSSS and Fast Hopping FHSS with LBT are very difficult to implement. In this case a low duty cycle applies (i.e. 0,1 % or 1 %) according to ECC Report 37 4. The transmi
33、tter on/off slew rate needs to be restricted due to the expected fast transmit/receive switching time by means of a spectrum mask. 4.2.1 Minimum transmitter off-time The minimum TX off-time allows other users without LBT facility to get access to a channel. 4.2.1.1 Definition TX-off is the minimum t
34、ime the transmitter shall remain off following a transmission, a communication dialogue between units or a polling sequence of other units. 4.2.1.2 Proposed limit The limit for TX-off is 100 ms. 4.2.2 Minimum listening time 4.2.2.1 Definition The minimum listening time is defined as the minimum time
35、 that the device listens in receiving mode after it has decided to transmit in order to determine whether the channel is available for use. The device must listen to the intended channel, for at least the specified minimum period, immediately prior to transmission. The listening time shall consist o
36、f the “minimum fixed listening time“ and an additional pseudo random part. If during the listening mode another user is detected then the device must not transmit before the channel is determined to be free again. Alternatively, the equipment can select another channel and start the listen time befo
37、re transmission. 4.2.2.2 Limit before first initial transmission The total listen time, tL, consists of a fixed part, tF, and a pseudo random part, tPS, as the following: PSFLttt += a) The fixed part of the minimum listening time, tF , shall not be less than 5 ms. b) The pseudo random listening time
38、 shall be randomly varied between 0 ms and 5 ms as the following: - If the channel is free at the start of the listen time, tL,then the pseudo random part, tPS,is automatically set to zero by the equipment itself. - If the channel is busy at the start of the listen time, tL, then pseudo random part,
39、 tPS, should be randomly varied in 0,5 ms steps between 0 ms and 5 ms. The limit for total listen time for the receiver consists of the sum of a) and b) together. 4.2.2.3 Acknowledge transmission There is no requirement for a listen time according to clause 4.2.2.2 before an acknowledge can be perfo
40、rmed. However, it shall be noted that if the start of an acknowledge is not received before the end of normal fixed part of the listen time (5 ms) then the channel might be taken by an other transmitter. ETSI ETSI TR 102 313 V1.1.1 (2004-07) 104.2.3 Maximum transmitter on-time A transmitter shall on
41、ly be allowed to transmit continuously for a maximum specified period. This will prevent a transmitter from occupying a channel for an extended period. The maximum on-time shall always be as short as possible for the application. However, SRD applications are often battery operated. To ensure long b
42、attery life the equipment will frequently operate at a very low power supply duty cycle and therefore each receiver activation will be limited. Therefore, the maximum transmitter on-time must be longer than the receiver battery supply off-time. 4.2.3.1 Definition The maximum transmitter on-time is d
43、efined as the maximum time the transmitter can be on during: a) A single transmission. b) Multiple transmissions and acknowledgements for a communication dialogue or polling sequence of other units under the condition that the channel is free. An equipment intended for very long messages must be cap
44、able of switching to a “free“ channel before the maximum transmitter on-time is reached for each channel of operation. 4.2.3.2 Proposed Limit The limit for a single transmission TX on-time is 1 s. The limit for a transmission dialogue or a polling sequence is 4 s. 4.3 Frequency agility 4.3.1 Definit
45、ion Frequency agility is the ability to determine an unoccupied sub-band or channel of operation in order to minimize interference with other users of the same band. The intention of the random frequency selection is to provide an aggregate uniform loading across the spectrum. This requires that the
46、 device shall select an operating channel out of a minimum of 2 channels from those listed in clause 4.1.1, so that the probability of selecting a given channel shall be the same for all channels. The probability of selecting each channel for “n“ channels is 1/n. The probability of selecting a given
47、 channel shall be the same for all channels. For FHSS: The probability of selecting a given channel shall be the same for all channels. All frequencies designated within 863 MHz to 870 MHz as described in the ECC Report 11 11 can be used with the exception of those for social alarms as specified in
48、ERC Recommendation 70-03 2. 4.3.2 Proposed limit It shall be noted that any change of frequency including FHSS frequency hopping shall not be made in the transmit mode. ETSI ETSI TR 102 313 V1.1.1 (2004-07) 114.4 Receiver parameters 4.4.1 Receiver threshold 4.4.1.1 Definition The receiver threshold
49、in the listening mode, is defined as the minimum level of an un-modulated carrier that can be detected. The receiver threshold is indirectly an essential requirement to fulfil the R environmental noise in band (industrial areas 5 dB to 10 dB). The present document suggests setting the LBT threshold to +6 dB above the typical sensitivity level to avoid equipment detecting noise in the band as a channel busy signal. The proposed thresholds are given in table 1. Table 1: Receiver threshold Receiver bandwidth Receiver threshold
