CEPT
ECC PT1(16)125
ECC
Electronic Communications Committee
ECC PT1 # 53
Budapest, Hungary, 12-16 September 2016
Date issued:
7 September 2016
Source:
Huawei Technologies
Subject:
NB-IoT and the ECC framework for MFCN frequency bands
Group membership required to read? (Y/N)
N
Summary:
In this contribution we examine the suitability of the ECC regulations in relation to the deployment
of the NB-IoT cellular radio technology for the provision of M2M communications in MFCN
frequency bands.
We consider the in-band, guard-band, and standalone modes of operation of NB-IoT, and address
the question of whether compliance with existing regulatory technical conditions is sufficient to
appropriately manage the risk of harmful interference to other users of the spectrum.
With the explicit understanding that the ETSI harmonised standards for LTE (including EN 301
908-13/14) also cover NB-IoT, which is a member of the 3GPP family of evolved universal
terrestrial radio access (E-UTRA) technologies, we conclude that
1) Changes to the ECC regulations are not necessary in order to accommodate in-band or guardband NB-IoT within spectrum used by MFCN. However, it would be prudent to clarify in ETSI
harmonised standards EN 301 908-13 and EN 301 908-14 that measurements of EIRP for inband and guard-band NB-IoT apply to the total composite {NB-IoT + LTE} signal transmitted
by the radio equipment.
2) Changes to the ECC regulations are not necessary in order to accommodate standalone NB-IoT
in the 900 and 1800 MHz bands. However, it would be prudent to a) amend ETSI harmonised
standard EN 301 908-13 to align the transmitter maximum output power of standalone NB-IoT
user equipment with that of GSM user equipment, and b) clarify in ETSI EN 301 908-14 that
the transmitter maximum output power of standalone NB-IoT base stations should correspond
to the EIRP limit for GSM base stations.
Further details are described in the Annex.
Proposal:
ECC PT1 is invited to send a liaison statement to ETSI with the request to accommodate the
relevant NB-IoT requirements in the relevant ETSI Harmonised Standards for IMT cellular
networks; covering the essential requirements of article 3.2 of the Radio Equipment Directive
2014/53/EU; Evolved Universal Terrestrial Radio Access (E-UTRA).
Background:
ECC PT1 at its 52nd meeting (19-21 April 2016) discussed the initial draft M2M report and further
updated the work item definition (doc ECC PT1(16)083_A22) which was subsequently approved by
the ECC meeting in June 2016. ECC PT1 agreed to progress the work in a correspondence group
(ECC PT1(16)083_A30) and review the draft report at its meeting in 12-16 September 2016.
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ANNEX
NB-IoT and spectrum for MFCN in Europe
1. Introduction
NB-IoT is a narrowband wireless technology specified by 3GPP and optimised for the provision
of M2M communications for the Internet of Things via cellular mobile networks.
In this paper we examine the extent to which the existing spectrum regulations in Europe might
be suitable for the deployment of the NB-IoT cellular radio technology in frequency bands that
are used by Mobile/Fixed Communications Networks (MFCN).
We first consider the principles of service and technology neutrality, and examine their
relevance to the provision of M2M communications services via NB-IoT.
We then address the three modes of operation of NB-IoT radios, and discuss their implications
with respect to compliance with regulatory technical conditions.
2. Service neutrality
Most frequency bands that are licensed and used by mobile network operators for the provision
of mobile broadband in Europe are harmonised and designated to MFCN by the ECC.
For this reason, the spectrum usage rights in bands licensed to mobile network operators are not
strictly service neutral. This poses the question of whether the use of spectrum by NB-IoT for
the provision of M2M communications is consistent with a ECC designation of the spectrum to
MFCN.
There is a strong argument that this is indeed the case, for the following reasons:
a) NB-IoT is a member of the 3GPP family of E-UTRA IMT technologies specifically
designed for cellular mobile networks operating in licensed spectrum to efficiently utilise
the radio resource for the support of large numbers of low data-rate communication
links. Accordingly, there are no obvious reasons why such use of spectrum by NB-IoT
might be incompatible with regulatory designations of spectrum to MFCN.
b) Importantly, there is precedence in Europe for the use of spectrum licensed to mobile
network operators for the purpose of delivering M2M communications. Examples
include the use of GSM in the 900 MHz band for the purposes of utility meter reading,
wide-area control/telemetry of street lighting, and asset tracking, to name but a few use
cases.
Accordingly, one can conclude that the designation to MFCN of spectrum that is licensed and
used by mobile network operators does not represent any regulatory barriers towards the use of
the same spectrum for M2M communications via technologies such as NB-IoT1.
1 Similar arguments and conclusions apply to the EC-GSM and eMTC radio technologies.
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3. Technology neutrality
Frequency bands that are licensed and used by mobile network operators for the provision of
mobile broadband in Europe are regulated via least restrictive technical conditions that are
specified in the relevant ECC Decisions. These technical conditions (or a subset thereof) are
incorporated into corresponding EC Decisions that are legally binding on the EU Member
States.
These regulatory technical conditions are typically in the form of frequency arrangements (band
plans) and EIRP limits for individual equipment, and are invariably technology neutral. The
rationale behind the principle of technology neutrality is that the market – rather than the
regulator – is best placed to decide on the most suitable technology.
The technical conditions specified in ECC/EC Decisions, along with any country-specific
regulatory requirements2, are included in the licences that are issued to mobile network
operators by national administrations.
Since the regulatory technical conditions are technology neutral, they do not – by definition –
either mandate or preclude the deployment of any specific radio technology by mobile network
operators.
One can conclude that, so long as the composite signal3 radiated from the radio equipment in
spectrum designated to MFCN complies with the relevant regulatory technical conditions, there
ought to be no regulatory barriers towards the use of the said spectrum by NB-IoT.
4. Block edge masks
Regulatory EIRP limits in ECC and EC Decisions are described in the form of technology neutral
block edge masks (BEMs). These BEMs are designed for the purpose of managing the likelihood
of harmful interference to services inside and outside a given band.
As shown in Figure (1), a BEM consists of in-block and out-of-block EIRP limits. A block is the
smallest range of frequencies that a regulator authorises for use.
Regulatory in-block EIRP limits are specified to mitigate interference from mobile/fixed
communications networks to other users of spectrum. ECC and EC Decisions usually only
specify a range of values for in-block EIRP limits as applied to MFCN base stations. Whereas
certain national regulators define a single value for such limits in the licences which they issue
to mobile network operators.
Regulatory out-of-block EIRP limits which apply inside a band designated to MFCN are
specified to mitigate interference between mobile/fixed communications networks in adjacent
blocks. These limits are in most cases fully consistent with the spectrum emission masks that are
specified at 3GPP (or elsewhere) for the most likely radio technology to be deployed in the said
band (e.g., LTE in the 800 MHz band).
Regulatory out-of-block EIRP limits which apply outside a band designated to MFCN are
specified to mitigate interference from mobile/fixed communications networks to other services
in neighbouring bands (e.g., digital terrestrial TV below the 800 MHz band). For this reason,
these limits might be more stringent than the spectrum emission masks specified in 3GPP
technical specifications.
2 Examples of country-specific regulatory requirements include limits on the maximum in-block EIRP of base
stations, or coverage obligations.
3 The term composite refers to the situation where the radio equipment radiates both NB-IoT and LTE signals.
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Figure (1): Regulatory block edge masks. Note that the EIRP limits are not
power spectral densities, but the maximum permitted power in a given bandwidth.
The EIRP limits of BEMs are specified as P dBm/(B MHz). The value of the bandwidth B for the
out-of-block limits is often chosen to account for the bandwidth of the radio links which might
be subject to harmful interference.
It should be pointed out that P is not a power spectral density. It specifies the maximum
permitted power to be radiated in a bandwidth B. In other words, it does not mandate or
preclude any specific power profiles as a function of frequency over bandwidth B. The technical
coexistence studies which result in the EIRP limits account for this neutrality with respect to the
distribution of power P over bandwidth B.
The question of compliance with regulatory technical conditions and BEMs in bands used by
MFCN is further explored in the following sections for the three distinct modes of NB-IoT
operation.
5. NB-IoT: In-band operation
Figure (2) illustrates an example of the in-band mode of operation, whereby a NB-IoT carrier
substitutes a 180 kHz LTE resource block for the provision of M2M communications in a 10
MHz wide MFCN block. Here the implicit assumption is that the radio transmitter radiates
both the in-band NB-IoT signal(s) and the LTE signal. Also shown are examples of the BEMs
which might apply to the licensed block.
Figure (2): NB-IoT in-band operation. No regulatory obstacles should exist,
so long as the composite {NB-IoT + LTE} signal complies with the regulatory BEMs.
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Note that the NB-IoT and LTE signals share4 the total EIRP of the radio equipment. For this
reason, the use of NB-IoT will not impact the compliance of the composite {NB-IoT + LTE}
signal with the in-block EIRP limit.
Furthermore, given the narrowband nature of the NB-IoT carrier, and the fact that the NB-IoT
carrier simply substitutes a LTE resource block, it is almost certain that the unwanted emissions
from the NB-IoT carrier will not impact the compliance of the composite {NB-IoT + LTE}
signal with the out-of-block EIRP limits.
Given the above, so long as the composite {NB-IoT + LTE} signal radiated by radio equipment
complies with the applied regulatory technical conditions and BEMs, there ought to be no
regulatory impediments towards the deployment of NB-IoT in a MFCN block. This applies to
both in-band NB-IoT user equipment and base stations.
Conformance with the essential requirements of the Radio Equipment Directive can as usual be
demonstrated via compliance with the relevant ETSI harmonised standards for E-UTRA IMT
cellular networks5 (which would also cover NB-IoT). It might be prudent to clarify the principle
regarding the composite signal in ETSI EN 301 908-13 (UE) and 301 908-14 (BS).
Conclusion: Changes to the ECC regulations are not necessary in order to accommodate inband NB-IoT within spectrum used by MFCN. It would be beneficial to clarify in the relevant
ETSI harmonised standards that measurements of EIRP for in-band NB-IoT apply to the total
composite {NB-IoT + LTE} signal transmitted by radio equipment.
6. NB-IoT: Guard-band operation
Figure (3) illustrates an example of the guard-band mode of operation, whereby one or two NBIoT carriers are inserted within the internal 500 kHz guard-band of a LTE carrier for the
provision of M2M communications in a 10 MHz wide MFCN block. Again, the implicit
assumption is that the radio transmitter radiates both the NB-IoT signal(s) and the LTE signal.
Also shown are examples of the BEMs which might apply to the licensed block.
Figure (3): NB-IoT guard-band operation. No regulatory obstacles should exist,
so long as the composite {NB-IoT + LTE} signal complies with the regulatory BEMs.
4 For exampe, a working assumption is that a NB-IoT carrier at most accounts for 35 dBm of the total 43 dBm (1/6th)
available at the output of a base station’s power amplifier.
5 ETSI EN 301 908-1, EN 301 908-11, EN 301 908-13, EN 301 908-14.
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Once again, the NB-IoT and LTE signals share6 the total EIRP of the radio equipment. For this
reason, the use of NB-IoT will not impact the compliance of the composite {NB-IoT + LTE}
signal with the in-block EIRP limit.
Furthermore, the internal guard-bands are used to ensure that the unwanted emissions of a LTE
carrier can readily comply with the 3GPP spectrum emission masks and any regulatory out-ofblock EIRP limits. For this reason, the mobile network operators and equipment vendors must
ensure that sufficient margins are in place, so that the unwanted emissions from the guard-band
NB-IoT carriers do not impact the compliance of the composite {NB-IoT + LTE} signal with the
out-of-block EIRP limits.
In summary, the guard band mode of NB-IoT operation is precisely analogous to a scenario
whereby one or two additional LTE resource blocks near the block edge are switched on. This is
certainly not precluded by the BEMs. For this reason, so long as the composite {NB-IoT + LTE}
signal radiated by radio equipment complies with the applied regulatory technical conditions
and BEMs, there ought to be no regulatory impediments towards the deployment of NB-IoT in a
MFCN block. This applies to both NB-IoT user equipment and base stations.
As proposed earlier, it might be prudent to clarify the above principle regarding the
requirements on the composite signal in ETSI EN 301 908-13 (UE) and 301 908-14 (BS).
Conclusion: Changes to the ECC regulations are not necessary in order to accommodate
guard-band NB-IoT within spectrum used by MFCN. It would be beneficial to clarify in the
relevant ETSI harmonised standards that measurements of EIRP for guard-band NB-IoT apply
to the total composite {NB-IoT + LTE} signal transmitted by radio equipment.
7. NB-IoT: Standalone operation
Figure (4) illustrates the standalone mode of operation, whereby a NB-IoT carrier
independently provides M2M communications in a MFCN block. Such a block might be in the
900 MHz band, where the NB-IoT carrier replaces legacy GSM carriers.
Figure (4): NB-IoT standalone operation. No regulatory obstacles should exist,
so long as the NB-IoT signal complies with the regulatory BEMs.
As discussed before, so long as the NB-IoT signals radiated by radio equipments comply with
the applied regulatory technical conditions and BEMs, there ought to be no regulatory
impediments towards the deployment of standalone NB-IoT in the MFCN block.
6 For example, a working assumption is that a NB-IoT carrier at most accounts for 35 dBm of the total 43 dBm (1/6th)
available at the output of a base station’s power amplifier.
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We next examine this in relation to the 900 MHz and 1800 MHz bands.
EC Decision 2011/251/EU harmonises the technical conditions for the availability and efficient
use of the 900 and 1800 MHz bands for terrestrial systems capable of providing electronic
communications services. These technical conditions are consistent with ECC Decision (06)13.
Specifically, the 900 and 1800 MHz bands are designated for GSM, UMTS, LTE, and WiMAX.
The bands may also be used by other Mobile systems provided that they can coexist with GSM,
UMTS, LTE and WiMAX (in adjacent blocks). The designation is with reference to the relevant
ETSI harmonised standards, including EN 301 502 and EN 301 511 for GSM, and EN 301 8081/11/13/14 for LTE.
The 900 MHz band was the original GSM band. The above Decisions are intended to regulate
the use of the 900/1800 MHz bands in a technology neutral manner.
Note that the out-of-block EIRP limits specified in EC Decision 2011/251/EU and ECC Decision
(06)13 are no more restrictive than the corresponding 3GPP technical specifications for GSM,
UMTS, LTE and WiMAX (via reference to the respective ETSI harmonised standards).
However, national administrations often apply regulatory technical licence conditions on the inblock EIRP of MFCN base stations (typically measured and averaged over the useful part of a
transmitted burst, and applicable in all directions).
Table (1) and Figure (5) show the technical conditions set out for GSM and LTE in the 900/1800
MHz licences in the UK. In addition to in-block EIRP limits, the UK technical licence conditions
also include limits on the channel centre/edge frequencies in relation to the block edge.
Table (1): The power transmitted (in EIRP) in any direction on the downlink frequencies of
the permitted frequency blocks by the radio equipment shall not exceed the values below.
Technology
for GSM
for UMTS
for LTE
for WiMAX
900 MHz spectrum
62 dBm per carrier
65 dBm per carrier
65 dBm per 5 MHz
65 dBm per 5 MHz
1800 MHz spectrum
62 dBm per carrier
65 dBm per carrier
65 dBm per 5 MHz
65 dBm per 5 MHz
Figure (5): GSM and LTE technical licence conditions for the 900 and 1800 MHz bands in the UK.
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One can identify two lines of argument regarding applicability of the above technical licence
conditions to standalone NB-IoT:
1) On the one hand, being a member of the 3GPP family of E-UTRA IMT cellular radio
technologies, a NB-IoT carrier can be viewed as equivalent to a wideband LTE carrier
with all but one resource block switched off. As discussed before, this is not precluded by
the applicable technical licence conditions. For this reason, it can be concluded that the
900/1800 MHz technical licence conditions for LTE should also apply to NB-IoT.
This implies that the NB-IoT must comply with an in-block EIRP limit of 65 dBm and
the LTE spectrum emission mask, and with its channel edge 200 kHz or more from the
block edge if the neighbour deploys GSM. We note that compliance with the LTE
spectrum emission mask can be readily achieved.
2) On the other hand, one can argue that in the context of its propensity to cause harmful
interference, a NB-IoT carrier is more similar to GSM than LTE. It can then be
concluded that the 900/1800 MHz technical licence conditions for GSM should apply to
NB-IoT.
This implies that the NB-IoT must comply with a maximum permitted EIRP of 62 dBm
and the GSM spectrum emission mask, and with its channel edge 100 kHz (or more)
from the block edge. We note that compliance with the GSM spectrum emission mask
can be readily achieved.
The outcomes of the two approaches are not so different, and in practice only restrict the inblock EIRP of a standalone NB-IoT carrier (compliance with the GSM or LTE out-of-block
masks can be readily achieved). Both approaches will result is a low likelihood of harmful
interference from standalone NB-IoT to other users of the spectrum, and certainly no more
than would be the case for LTE or GSM.
One might choose to opt for approach (2) as a cautious measure, given that both NB-IoT and
GSM use narrowband carriers.
In any case, the approaches do not require a change in ECC Decision (06)13 or EC Decision
2011/251/EU. However, based on approach (2), the following would provide sufficient clarity:
a) a clarification in ETSI harmonised standard ETSI EN 301 908-13 (UE) to align the
transmitter maximum output power of standalone NB-IoT user equipment with that of
GSM user equipment.
b) a clarification in ETSI harmonised standard ETSI EN 301 908-14 (BS) that the
transmitter maximum output power of standalone NB-IoT base stations should
correspond to the EIRP limit for GSM base stations.
Conclusion: Changes to the ECC regulations are not necessary in order to accommodate
standalone NB-IoT within the 900 and 1800 MHz bands. It would be beneficial to a) amend the
relevant ETSI harmonised standard to align the transmitter maximum output power of
standalone NB-IoT user equipment with that of GSM user equipment and b) clarify in the
relevant ETSI harmonised standard that the transmitter maximum output power of standalone
NB-IoT base stations should correspond to the EIRP limit for GSM base stations.
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8. Other technical licence condition
Mobile network operator licences often include technical conditions in addition to harmonised
in-block and out-of-block EIRP limits. Examples include country-specific requirements, such as
geographic or population coverage obligations
While appropriate for mobile broadband, such licence conditions may not be deemed
appropriate for the provision of M2M communications services. Fortunately, coverage
obligations are usually specified explicitly for voice or mobile broadband services. As such, any
amendments to the licences in relation to these obligations are most likely not necessary.

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