(99)43 - Ofcom

ETSI TM4; Sophia Antipolis
13th – 17th December1999
Doc ………….
29th November 1999
MWS in the band 40.5-43.5GHz.
UK Radiocommunications Agency
Proposal for input to WI DE/TM04097 regarding MWS at 40GHz.
Barry Lewis
Tel: +44 207 211 0313
Fax: +44 207 211 0115
Mobile: +44 774 7837627
e-mail: [email protected]
40GHz MWS Work Item; DE/TM04097
The definition of MWS includes systems used for the distribution of video/broadcasting material.
These uni-directional systems known also as Multipoint Video Distribution Systems (MVDS) could
also form the basis for bi-directional systems with the addition of a return path or interaction
channel from subscriber to central station. In the UK uni-directional MVDS have been
characterised from a co-existence point of view in UK specification MPT1560. This contribution
provides detail from MPT1560 as a contribution to the MWS at 40GHz Work Item. Much of the
material in MPT1560 is a sub-set based upon ETS300-748 (Digital Video Broadcasting (DVB):
Multipoint Video Distribution Systems (MVDS) at 10GHz and above).
MWS Standard Approach
The range of possibilities for MWS could entail a number of approaches to this work item.
Possibilities might be;
1) Differing equipment classes based upon some key characteristics such as;
 Uplink/Downlink assymetry
 Single carrier / Multi-carrier
2) A generic approach. This could lead to characteristics such as spectrum masks , for example,
defined in relative terms rather than with reference to specific channelisation. Although still
under consideration, it is anticipated that assignments for MWS are most likely to be made to
operators based upon block allocations. This may lead to a requirement to specify “block
edge” characteristics rather than (or as well as) characteristics linked directly to channel
It is not clear at this stage which approach may be the best so the information from MPT1560 is
presented here in a specific form with some suggestions for adaptation for either approach.
Characteristics of MVDS form of a MWS
See Annex 1.
The characteristics presented have been extracted directly from MPT 1560 and as such may
include specific references that need adapting for inclusion in a TM4 work item. For example the
approach taken when MPT 1560 was drafted may not reflect current TM4 thinking on the
presentation of some characteristics. As stated above some comments and suggestions have
been added where appropriate.
Annex 1
Multipoint Video Distribution System (Ref: UK MPT 1560 Version 1)
1.2 Transmission channel capacity
The transmission path shall be capable of accepting baseband digital input signals in accordance
with ETS 300 421. Other digital video signals are not precluded.
This standard sets no upper or lower limit to the symbol rate for the coherent QPSK channel
bandwidth. However, a 33 MHz (-3 dB) bandwidth would give a maximum value 25.776 MBaud.
Comment: The bandwidth is specific to a symbol rate and error coding overhead. (More information
in ETS300-748). The absolute channel bandwidth may need revision based upon more information
concerning this issue that may be available from the DVB-RCCL group as a result of liaison with the
2.1 Frequency error
The frequency error of each carrier, under both normal and extreme test conditions shall not
± 12.5 ppm (± 0.5 MHz @ 40 GHz)
Comment: IEEE 802.16 is considering a frequency tolerance of± 10 ppm for its BWA Coexistence Recommended Practice.
The nominal frequency relationship (channel spacing) between carriers must at all times be
constant at 39 ± 1.0 MHz. See comment in section 1.2 above.
2.2 Carrier power
The carrier output power (Central Station) under normal and extreme test conditions shall not
exceed the manufacturers rated output power (which is normally limited to 500 mW per channel) by
more than 2 dB. For power exceeding 500 mW per channel, further consideration will need to be
given [by the Radiocommunications Agency.]
Comment: There may be scope to review this figure in the light of developments on co-ordination
issues under consideration within CEPT SE19 and ETSI BRAN.
2.3 Spurious emissions
The power of any spurious emission shall not exceed -80 dBW within the frequency range 42.5
GHz to 43.5 GHz, to protect the Radio Astronomy Service. Spurious emissions outside the above
frequency range shall not exceed the following absolute values:
30.0 MHz to 21.2 GHz
21.2 GHz to 40.5 GHz
42.5 GHz to 43.5 GHz
43.5 GHz to 80.0 GHz
80.0 GHz to 90.0 GHz
-90 dBW
-60 dBW
-80 dBW
-60 dBW
-50 dBW
Comment: These figures need to be brought into alignment with Recommendation 74-01.
Therefore suitable text might be:
According to ITU-R Recommendation F.1191 [yy], and CEPT/ERC Recommendation 74-01 [xx],
the external spurious emissions are defined as emissions at frequencies which are outside the
nominal carrier frequency +/- 250% of the relevant channel separation.
The limits of these emissions shall conform to CEPT/ERC Recommendation 74-01 [xx]
The following is an extract from Annex 1 of Rec. 74-01:
Type of equipment
Fixed Service (all station except those
Fixed Service - Terminal station (out
station with subscriber equipment
interfaces)(note 2)
Fixed Service – Receivers
mean power or, when applicable, average power during
bursts duration in the reference bandwidth
-50 dBm
9 kHz(note 3)  f  21.2 GHz(note 1)
-30 dBm
-40 dBm
21.2 GHz < f (see recommend 3) (note 1)
9 kHz(note 3)  f  21.2 GHz(note 1)
-30 dBm
21.2 GHz < f (see recommend 3) (note 1)
The same limits as for the transmitters above apply
Note 1 : For digital systems it is necessary to provide one or more steps of reference bandwidth to produce suitable transition area
for the spectral density to manage the required limit because in some frequency bands and/or applications narrow band RF
filters are not technically or economically feasible.
Consequently, just outside the  250% of the relevant Channel Separation, the limit of spurious emissions are defined
with reference bandwidths as detailed by the specific Figure 1.1 and the related Table 1.2;
Note 2 : Point-to-Multipoint systems used in CEPT countries foresee three kind of stations :
Master (Central) Station (clearly identifiable in SM.329)
Terminal Station (also clearly identifiable in SM.329)
Repeater Station (which is not referred in SM.329);
Repeater Stations of Point-to-multipoint systems will be considered as Terminal stations when they are intended for use
only in Remote stations not co-located with any other Fixed radio equipment classified as Central station.
Note 3 : In ITU-R Recommendation SM.329 from 9 kHz to 30 MHz only Category A limits (i.e. -13 dBm) apply also when Category
B is selected, however CEPT will propose revision to SM.329 in order to extend Category B limits down to 9 kHz.
This would imply new limits as below compared to the existing MPT1560 limits;
30.0 MHz to 21.2 GHz
21.2 GHz to 40.5 GHz
42.5 GHz to 43.5 GHz
43.5 GHz to 80.0 GHz
80.0 GHz to 90.0 GHz
-90 dBW
-60 dBW
-80 dBW
-60 dBW
-50 dBW
Rec 74-01: -50dBm
Upper frequency bound would be 87.0GHz rather than 90.0GHz.
Comment; Is a reference to EN 301-390 needed here (Spurious emissions and receiver immunity at
antenna ports for DRRS)?
2.4 Radiated spectrum
(a) The 0 dB Spectrum Reference Level (SRL) for the spectrum mask shown in figure 2.1 [shall
be set to the level calculated by the following formula:]
(c) The residual carrier level shall not exceed -15 dB relative to the value of the unmodulated
Proposal: This mask could be re-drawn as EN 301-213-3 Figure 1, System A with the following
table detailing the break points.
If acceptable the first plateau has been reduced from –20dB to –23dB and the frequency
tolerance (0.5MHz) has been be removed.
0db Point A
0.38 x
[-23]dB Point
0.56 x Ch.
[-23]dB Point
0.76 x Ch.
-45dB Point D
-45dB Point E
1.4 x Ch.
2.5 x Ch.
Spectral density (dB)
Frequency Reference Points
EN301-213 –3 Spectrum Mask – System Type A
2.5 Summary Of (current MPT 1560) Transmitter Parameters
Frequency band of operation
40.5 GHz to 42.5 GHz
Frequency of transmission
See Annex 5 Channel Plan
Nominal channel spacing
39 MHz
Frequency stability of transmission
± 0.5 MHz of nominal
centre frequency
Transmitter output power per
 500 mW ( which corresponds to
 -3 dBW)
Spurious emissions
[30.0 MHz to 21.2 GHz < -90 dBW
21.2 GHz to 40.5 GHz < -60 dBW
40.5 GHz to 42.5 GHz
42.5 GHz to 43.5 GHz < -80 dBW
43.5 GHz to 80.0 GHz < -60 dBW
80.0 GHz to 90.0 GHz < -50 dBW]
Spectral power density referred to
nominal carrier frequency
See Fig 2.1
Modulation Scheme
QPSK (see note)
Channel Coding
DVB/S compliant (see note)
Data Transport Multiplex
MPEG 2 (see note)
2.6 Domestic Receiver Performance
[Comment: Informative only in MPT1560]
Performance of Outdoor/Indoor Units for information (assumed in drawing up specification)
a) Outdoor Unit
Frequency range
Noise figure
40.5 - 42.5 GHz
6 dB
Co-polar gain of receiving antenna
32 dBi (see figure A2.1) (see
Cross-Polar discrimination at bore-sight
20 dB
Amplitude - Frequency Characteristic
Gain Ripple:
0.5 dB over any 33 MHz
< 5 dB across received band
Polarisation of receiving antenna
Frequency of local oscillator
See Annex 4
Stability of local oscillator
± 2.5 MHz
Group Delay Characteristic
20 ns in any 33 MHz bandwidth
Channel polarisation (odd numbers)
(even numbers)
note: The use of other antenna patterns is not precluded. The value of gain stated has however
been assumed for planning purposes.
b) Indoor Unit
Frequency range
0.95 - 2.05/2.150 GHz
Signal input at 1st IF to reach QPSK demodulation
threshold and to achieve a bit error rate of 2x10-4
-60 dBm (Zin = 75  nominal)
Maximum tuning error for worst selected channel
± 0.25 MHz
Rejection of adjacent (N+2) odd or even channels
25 dB
Channel bandwidth
33 MHz nominal
Channel spacing
39 MHz
Frequency range of modulated UHF output
Channels 21 - 69
2.7 Typical Digital MVDS Link Budget
Transmitter Power:
Transmitter antenna gain:
Thermal noise (KTB) (Receiver bandwidth 33
Receiver Noise Figure:
Noise Output Level:
Required Carrier to Noise:
Receive antenna gain:
Receive antenna pointing error:
Minimum Carrier Level:
-3.0 dBW
15.0 dBi
12.0 dBW
- 128.8 dBW
6.0 dB
-122.8 dBW
6.8 dB
32.0 dBi
2.0 dB
-146.0 dBW
Required path loss for service:
-158 dB
Free Space attenuation:
Atmospheric losses
(0.14 dB/km):
Rain attenuation (rain rate 12 mm/h,
corresponding to 3.67 dB/km):
Service Distance:
138.6 dB
0.7 dB
18.7 dB
5.1 km
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