Fixed Point-to-Point Radio Services with Digital Modulation Operating in the Frequency Range 24.5 to 26.5 GHz

Technical Frequency Assignment Criteria

Fixed Point-to-Point Radio Services with Digital Modulation Operating in the Frequency Range 24.5 to 26.5 GHz

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Foreword

It is required by the Wireless Telegraphy Acts, 1949 and 1998 that no radio apparatus shall be installed or used in the United Kingdom, except under the authority of a licence granted by the Secretary of State. It is a condition of such a licence that the performance of the radio equipment meets certain minimum standards laid down in the UK Radio Interface Requirement 2000 (UK RIR 2000). Compliance will have been notified in accordance with the R&TTE (Radio Equipment and Telecommunications Terminal Equipment) Directive.

This document details the frequency assignment criteria and principles that will be employed by Radiocommunications Agency (RA) in the selection of frequencies for use by compliant fixed terrestrial (point-to-point) digital radio equipment operating in the band or frequency range specified.

These assignment criteria are subject to updating and amendment, and intending operators/manufacturers should consult the latest version of this document complete with any amendments. Single copies of this document are available free from the RA library at the address below:

Radiocommunications Agency
Library Services
Wyndham House
189 Marsh Wall
London E14 9SX.

Switchboard and 24 hour enquiry service:
Telephone: 020 7211 0211

Library and Publicity:
Telephone: 020 7211 0502/0505
Fax: 020 7211 0507

1.	General
	1.1	Introduction
	1.2	Licensee's responsibility
	1.3	Minimum path lengh policy
2.	Transmitting and Receiving Installations
	2.1	General
	2.2	Antenna directivity
	2.3	Antenna polarisation
	2.4	Equivalent Isotropically Radiated Power (EIRP)
	2.4.1	Inter-serivce sharing
3.	Principles of Assignment and EIRP Derivation
	3.1	Normal assignment
	3.1.1	Normal assignment flow diagram
	3.2	Multi-section links and repeater stations
	3.2.1	Multi section links
	3.2.2	Passive repeaters
	3.3	Go – return separation
	3.4	Parallel links operating over the same path
	3.5	Antenna discrimination
	3.6	Path clearance
	3.6.1	Obstructed paths
	3.7	Path loss
	3.7.1	Median path loss
	3.7.2	Gaseous absorption
	3.8	Availability
	3.9	Receiver signal levels
	3.10	Fade margin
	3.10.1	General
	3.10.2	Clear-air fade margin
	3.10.3	Rain fade margin
	3.11	Equivalent isotropically radiated power calculation
4.	Interference Assessment
	4.1	General
	4.2	Interference limits
	4.3	Co- and adjacent-channel limits
	4.4	Mulitiple interferers
5.	Channel Plan
	5.1	Derivation of radio frequency channels for the 24.5 to 26.5 GHz band
Annex A:		Receiver Signal Levels and Interference Levels
Annex B:		Wanted to Unwanted Ratios
Annex C:		Norm al Assignment Process – Flow Diagram
Annex D:		Assigning Passive Repeater Stations
Annex E:		High-Level Flow Diagram for Recommendation ITU-R P.452
Annex F:		UK Rain Rates in mm/hr for 99.99% Availability by National Grid Square
Annex G:		Document History

1. General

1.1 Introduction

This document outlines the frequency assignment criteria and principles that will be employed by RA in the selection of frequencies for use by fixed terrestrial (point-to-point) digital radio services operating in the frequency range 24.5 to 26.5 GHz.

The channel plan shall be in accordance with that given in Section 5.

This document takes into account the equipment standards EN 300 431 and EN 302 062. RA willcurrently license the following classes of equipment:

	Class 2	equipment performance based on typically 4-state modulation schemes (e.g. 4-FSK, 4-PSK or equivalent);
	Class 3	equipment performance based on typically 8-state modulation schemes (e.g. 8-PSK or equivalent);
	Class 4	equipment performance based on typically 16- or 32-state modulation schemes (e.g. 16-QAM, 32-QAM or equivalent);
	Class 5	equipment performance based on typically 64- or 128-state modulation schemes (e.g. 64-QAM, 128-QAM or equivalent):
	Class 5a –	Adjacent-Channel Alternate Polarisation (ACAP) operation; and
	Class 5b –	Adjacent-Channel Co- Polarisation (ACCP) operation.

1.2 Licensee's responsibility

The Foreword of this document states that the establishment, use or installation of transmitting or receiving apparatus is subject to the issue of a licence by the Secretary of State. The licensee must ensure that equipment conforms with and is maintained to the standards referenced in IR2000.

1.3 Minimum path length policy

RA operates a 'minimum path length' policy to promote the use of the highest possible frequency band for the distance over which the link is to operate. For the 24.5 to 26.5 GHz band, the minimum path length is 3 km for systems with traffic rates below 140 Mbit/s. 140/155 Mbit/s systems will be permitted where path lengths are > 2 km. Below these distances there will be some expectation that a higher frequency band, or alternative means of traffic transfer, could be used.

2. Transmitting and Receiving Installations

2.1 General

The transmitting and receiving installations shall conform to Sections 2.2 and 2.3 below, and shall be implemented in accordance with good engineering practice.

2.2 Antenna directivity

The antenna installation at the licensed premises shall be such that the antenna pattern will not exceed the co-polar and cross-polar Radiation Pattern Envelope (RPE) given in IR2000, with the zero-degree datum being the boresight path between the two stations.

2.3 Antenna polarisation

The plane of polarisation of emissions for a particular radio link will be specified by RA and will normally be vertical linear polarisation. Horizontal linear polarisation may be used at the applicant's request.

The antenna alignment surface shall be aligned as precisely as possible to the true vertical or true horizontal, and the misalignment shall be no greater than 3.

2.4 Effective isotropic radiated power (EIRP)

The assigned value of EIRP will be stated in the licence and must not be exceeded, although a tolerance of �3 dB on this assigned value will be allowed in practice. The maximum EIRP normally assigned will be 43 dBW.

2.4.1 Inter-service sharing

To facilitate spectrum sharing between fixed services and space services within the frequency range 25.25 to 26.5 GHz, there is a restriction imposed by Article 21 of the Radio Regulations (Table 21-1). The Radio Regulations state that fixed-service transmitting stations employing an EIRP density exceeding +24 dBW/MHz should avoid pointing towards the geostationary orbit by at least 1.5°. As a result, there is an additional limit on the EIRP that will be assigned to stations that do point to within 1.5° of the geostationary orbit, as detailed in Table 1 below:

Systems class	Capacity (Mbit/s) in bandwidth (MHz)	Maximum EIRP assigned
2	2 in 3.5	22.5 dBW
2	2 x 2 in 3.5	25.5 dBW
2	8 in 7	28.5 dBW
2	2 x 8 in 14	31.5 dBW
2	34 in 28	34.5 dBW
4	8 in 3.5	26 dBW
4	2 x 8 in 7	29 dBW
4	34 in 14	32 dBW
4	51 in 14	32.5 dBW
4	51 in 28	33.5 dBW
4	140/155 in 56	37.5 dBW
5a	140/155 in 28	35.5 dBW
5b	140/155 in 28	35.5 dBW
5a	311 in 56	41.5 dBW
5b	311 in 56	41.5 dBW
Table 1: Additional EIRP limits.

3. Principles of Assignment and EIRP Derivation

3.1 Normal assignment

A normal frequency assignment for a single or multi-section bi-directional link shall comprise a pair of radio frequencies of corresponding channel number, one from each of the low and high frequency groups.

3.1.1 Normal assignment flow diagram

Annex C shows a flow diagram for the normal assignment process.

3.2 Multi-section links and repeater stations

3.2.1 Multi-section links

In the case of a multi-section link, the direction of transmission of the two frequencies shall alternate for successive repeater sections so that each station transmits only in one half (either the lower or upper half) of the band.

3.2.2 Passive repeaters

Passive repeater operation using either back-to-back antennas or planar reflectors will be allowed only under certain specific conditions. Use of these systems will be judged on a case-by-case basis. Passive repeaters are expected to be used only for availabilities of 99.99% or less in situations where:

a) the site for the repeater station is remote and power provision is extremely difficult;

b) there is a clear spectrum saving by the use of one repeater station to overcome the obstructed path rather than going around the obstruction with two or more conventional links;

c) use of the higher power needed for this operation does not unnecessarily sterilise the surrounding area and block further normal assignments; and

d) higher-performance antennas (if available) are used at the end stations, along with as large as reasonably possible repeater station antennas to maximise the repeater gain.

Detail of the assignment process modifications to deal with passive repeater operation is given in Annex D.

3.3 Go – return separation

The difference between a pair of corresponding go and return frequencies in the 24.5 to 26.5 GHz band shall be 1008 MHz.

3.4 Parallel links operating over the same path

In assessing the interference potential between parallel links operating over the same path, it is assumed that the wanted and interfering signals suffer correlated fading. Therefore, protection from interference is derived from frequency separation and cross-polar discrimination (if any).

To be classed as operating over the same path, the stations located at the sites at each end of the links must be within 10 m of each other in the horizontal plane and within 2 m in the vertical plane.

Table 2 lists the minimum frequency separations for like systems operating under these conditions. For mixed-capacity systems, the appropriate minimum separations are derived by halving the sum of the individual minimum separations given. The assignment software identifies available channels that meet the minimum frequency separation criteria, in accordance with the channel plan defined in Section 5.

Spectrum efficiency Class	Minimum capacity (Mbit/s)	Minimum separation between carriers on a parallel route operating over the same path
Spectrum efficiency Class	Minimum capacity (Mbit/s)	Co-polar (MHz)	Cross-polar (MHz)
2	2	3.5	3.5
2	2 x 2	3.5	3.5
2	8	7	7
2	2 x 8	14	14
2	34	28	28
4	8	3.5	3.5
4	2 x 8	7	7
4	34	14	14
4	51	14	14
4	51	28	28
4	140/155	56	56
5a	140/155	56	28
5b	140/155	28	28
5a	311	112	56
5b	311	56	56

Table 2: Frequency separations.

3.5 Antenna discrimination

In assigning frequencies for links in the same geographical area due consideration shall be taken of the antenna discrimination. When available, data derived from a manufacturer's guaranteed RPE will be used. Otherwise, the appropriate RPE specified in ETSI standard EN 300 833 will be assumed.

3.6 Path clearance

It will usually be assumed that each hop has a clearance from obstructions of not less than 0.577F between the transmitting and receiving antennas at the two stations, under conditions corresponding to values of the ratio K greater than 0.7.

F: First Fresnel zone clearance

K: Ratio of effective earth radius to real earth radius

3.6.1 Obstructed paths

Obstructed paths will be allowed where their need is clearly demonstrated, with an EIRP increased up to a maximum of 6 dB above the normal assignment level, provided that the maximum limit of 43 dBW is not exceeded. Above this level, operators will be expected to accept the possibility of lower link availability. The following conditions will apply:

a) the higher power needed for this operation shall not unnecessarily sterilise the surrounding area and block further normal assignments;

b) the increase in EIRP will be allowed only if the obstruction cannot be overcome by increasing the antenna height;

c) higher-performance antennas (if available) should be used to minimise the sterilisation of surrounding areas, considering the higher-than-normal EIRP associated with this type of operation; and

d) the increased EIRP will only be allowed on link availabilities ≥ 99.90% and ≤ 99.99%.

Detail of the assignment process modifications to deal with operation over an obstructed path is given in Annex E.

3.7 Path loss

3.7.1 Median path loss

The median path loss between two stations is equal to the free space path loss (FSPL) plus the atmospheric gaseous absorption (see Section 3.7.2).

			FSPL = 92.45 + 20log(d) + 20log(f) Median path loss (dB) = FSPL + gaseous absorption
	where:		d = distance between the stations in km; f = frequency of operation inGHz;

3.7.2 Gaseous absorption

The link budget shall include contributions from gaseous absorption in addition to the basic FSPL. Gaseous absorption is based on oxygen and water vapour data obtained from ITU-R Recommendation P.676-2. At 25.5 GHz a worst-case gaseous specific attenuation of 0.18 dB/km shall be assumed, based on ground level, air temperature of 15°C and water vapour density of 10g/m3 (see ITU-R Recommendation P.836-1, Figure 4).

3.8 Availability

Availabilities greater than 99.99% are to be agreed with RA on a case-by-case basis.

NOTE: Throughout this specification, availability will be taken to mean propagation availability.

3.9 Receiver signal levels

Spectrum efficiency class	Capacity (Mbit/s) in bandwidth (MHz)	Receiver median signal level
2	2 in 3.5	-114 dBW + M
2	2 x 2 in 3.5	-111 dBW + M
2	8 in 7	-108 dBW + M
2	2 x 8 in 14	-105 dBW + M
2	34 in 28	-102 dBW + M
4	8 in 3.5	-106 dBW + M
4	2 x 8 in 7	-103 dBW + M
4	34 in 14	-101 dBW + M
4	51 in 14	-97 dBW + M
4	51 in 28	-101 dBW + M
4	140/155 in 56	-96 dBW + M
5a	140/155 in 28	-91 dBW + M
5b	140/155 in 28	-91 dBW + M
5a	311 in 56	-88 dBW + M
5b	311 in 56	-88 dBW + M
NOTE 1: M = fade margin. See Section 3.10. NOTE 2: A minimum fade margin of 10 dB will be allocated. NOTE 3: In the case of protected equipment an extra allowance, agreed on a case-by-case-basis with RA, may be allowed for receiver signal level. NOTE 4: All levels are referenced to point C on the system block diagram in EN 300 431. NOTE 5: The minimum bit rate values shown are configured in line with ETSI documentation.

Table 3: Receiver median signal levels.

The figures in Table 3 are derived from a link budget as given in Annex A.

3.10 Fade margin

3.10.1 General

Fade margins are calculated according to ITU-R Recommendation P.530-7 §2.3 and §2.4 for clear-air and hydrometeor (rain) fading respectively. Note that the Recommendation refers to clear-air fading as due to 'multipath and related factors'; the more general term 'clear-air' is used here.

The overall fade margin is calculated by apportioning the overall permissible unavailability between clear-air and rain fading. The assignment software utilises the equations for clear-air and rain fading given in P.530-7 §2.3 and §2.4 respectively to iterate for the value of fade for which the sum of the individual (clear-air and rain) unavailabilities equals the required overall unavailability. It is assumed that rain and clear-air fades do not occur simultaneously. For cases where the ratio of outage times for rain and clear-air exceeds 40, the smaller value is ignored when calculating the overall fade margin.

Links whose calculated fade is less than 10 dB will be allocated a fade margin of 10 dB.

3.10.2 Clear-air fade margin

The fade margin required for clear-air effects depends on frequency, path length, radio-climatic factors, and the service availability required. The fade exceeded for a given percentage of an average year is calculated according to ITU-R Recommendation P.530-7 §2.3.

3.10.3 Rain fade margin

The rain fade margin for a given availability depends on the path length, frequency, polarisation and geographic location. UK rain rates exceeded for 0.01% of an average year are shown in Annex F at the centre of each 100 km grid square. These rain-rate data are obtained from UK meteorological records.

The rain fade is derived using the higher of the rain rates exceeded for 0.01% of the time at the two terminals of each link,mm/hr.

The specific attenuation,, for the rain intensity is calculated for the required frequency and polarisation using equation 1 of ITU-R Recommendation P.838-1:

Values of regression coefficients k and a are given in Table 4 below for both horizontal (H) and vertical (V) polarisations. These have been derived by interpolation between the values in Table 1 of ITU-R Recommendation P.838-1, for the highest frequency in the band:

Frequency
26.5 GHz	0.141	0.128	1.048	1.020

Table 4: Regression coefficients

The path reduction term, r, is given in ITU-R Recommendation P.530-7 as:

where:

The effective path length, , is found by multiplying the actual physical path length, , by the reduction term r.

The path attenuation exceeded for 0.01% of the time is given by equation 37 of ITU-R Recommendation P.530-7:

where:

The attenuation,, exceeded for other time percentages p (over the range 0.001% to 1%) can be deduced from equation 38 of ITU-R Recommendation P.530-7:

3.11 Effective isotropic radiated power calculation

The licence schedule will detail the assigned EIRP for each transmitting station. This is based on the following calculation:

EIRP = Rx median signal level + Rx station feeder losses – Rx antenna gain + median path loss

The Rx (receiver) median signal level is as defined in Table 3. The maximum co-polar gain figure for the receiving antenna is used.

4. Interference Assessment

4.1 General

The link to be assigned is co-ordinated with all other links in the same frequency band within a co-ordination zone radius of 200 km around each site. The size of the co-ordination zone may be reviewed from time to time as operational experience is gathered. Interference to and from the proposed link is assessed, taking into account the path profile between the two stations. Use is made of antenna radiation patterns to obtain the gain of antennas in the direction of unwanted signals.

The two conditions considered in the evaluation of interference from each single-entry interference source are:

a) the median unwanted signal must be at least the wanted to unwanted (W/U) ratio below the faded wanted signal; and

b) the enhanced unwanted signal must be at least the W/U ratio below the median wanted signal.

If either of the above two conditions is not met, and an alternative frequency cannot be ascertained, the link will not be assigned.

The procedures followed are in line with ITU-R Recommendation P.452-7 and are outlined in the flow diagram shown in Annex E.

4.2 Interference limits

The interference limit is derived as follows:

Interference limit = {Receiver sensitivity level (RSL) for BER = 10-6} – W/U ratio

4.3 Co- and adjacent-channel limits

The maximum co-channel and adjacent-channel interference limits, at the receiver input, from a single unwanted source are shown in Tables 5 and 6. W/U ratios for single-entry interferers relating to mixed-capacity digital systems are shown in the matrices in Annex B.

The adjacent-channel interference limits given in Table 6 do not apply to links operating on a parallel path over the same hop. Under these circumstances, fading is assumed correlated with interference protection offered by frequency discrimination (and possibly cross-polar antenna discrimination, if applicable). See Section 3.4.

Spectrum efficiency class	Capacity (Mbit/s) in bandwidth (MHz)	W/U ratio (dB)	Interference limit (dBW)
2	2 in 3.5	25	-139
2	2 x 2 in 3.5	25	-136
2	8 in 7	25	-133
2	2 x 8 in 14	25	-130
2	34 in 28	25	-127
4	8 in 3.5	29	-135
4	2 x 8 in 7	29	-132
4	34 in 14	29	-130
4	51 in 14	32	-129
4	51 in 28	33	-134
4	140/155 in 56	33	-129
5a	140/155 in 28	36	-127
5b	140/155 in 28	36	-127
5a	311 in 56	41	-129
5b	311 in 56	41	-129

Table 5: Single-entry co-channel interference limits.

Spectrum efficiency class	Capacity (Mbit/s) in bandwidth (MHz)	W/U ratio (dB)	Interference limit (dBW)
2	2 in 3.5	1	-115
2	2 x 2 in 3.5	7	-118
2	8 in 7	4	-112
2	2 x 8 in 14	4	-109
2	34 in 28	4	-106
4	8 in 3.5	3	-109
4	2 x 8 in 7	3	-106
4	34 in 14	3	-104
4	51 in 14	3	-100
4	51 in 28	1	-102
4	140/155 in 56	1	-97
5a	140/155 in 28	7	-98
5b	140/155 in 28	0	-91
5a	311 in 56	9	-97
5b	311 in 56	3	-91

Table 6: Single-entry adjacent-channel interference limits.

4.4 Multiple interferers

In Tables 5 and 6 as well as Annex B, the single-entry digital W/U ratios include allowances for multiple interferers. The allowances are 4 dB for co-channel interferers and 6 dB for adjacent-channel interferers, independent of bit rate.

5. Channel Plan

5.1 Derivation of radio frequency channels for the 24.5 to 26.5 GHz band

Note: The 24.5 GHz to 26.5 GHz channel plan for the United Kingdom has been apportioned so that like capacities occupy the same part of the spectrum.

For the 24.5 to 26.5 GHz band, the radio frequency channel arrangements based on CEPT/ERC Recommendation T/R 13-02 E for carrier spacings of 56 MHz, 28 MHz, 14 MHz, 7 MHz and 3.5 MHz as illustrated in Figure 1 shall be derived as follows:

Let:	f_o	be the centre frequency of 25,501 MHz;
	f_n	be the centre frequency (MHz) of a radio frequency channel in the lower half of the band; and
	f_n'	be the centre frequency (MHz) of a radio frequency channel in the upper half of the band.
Individual channel frequencies are expressed by the following relationships:
a)		For systems with a carrier spacing of 56 MHz:
		Lower half of the band:	f_n = (f_o – 980 + 56n) MHz
		Upper half of the band:	f_n' = (f_o + 28 + 56n)	MHzwhere n = 1,2,3...16
b)		For systems with a carrier spacing of 28 MHz:
		Lower half of the band:	f_n = (f_o – 966 + 28n) MHz
		Upper half of the band:	f_n' = (f_o + 42 + 28n) MHz	where n = 1,2,3...32
c)		For systems with a carrier spacing of 14 MHz:
		Lower half of the band:	f_n = (f_o – 959 + 14n) MHz
		Upper half of the band:	f_n' = (f_o + 49 + 14n) MHz	where n = 1,2,3...64
d)		For systems with a carrier spacing of 7 MHz:
		Lower half of the band:	f_n = (f_o – 955.5 + 7n) MHz
		Upper half of the band:	f_n' = (f_o + 52.5 + 7n) MHz	where n = 1,2,3...128
e)		For systems with a carrier spacing of 3.5 MHz:
		Lower half of the band:	f_n = (f_o – 953.75 + 3.5n) MHz
		Upper half of the band:	f_n' = (f_o+ 54.25 + 3.5n) MHz	where n = 1,2,3...256

Figure 1: Channel arrangement for the 24.5 to 26.5 GHz frequency band.

Annex A: Receiver Signal Levels and Interference Levels

Tables A.1 to A.3 give examples of receiver signal levels and maximum permitted interference levels for digital systems operating in the frequency band 24.5 to 26.5 GHz.

Channel bandwidth (MHz)	3.5	3.5	7	14	28
Minimum bit rate (Mbit/s)	2	2 x 2	8	2 x 8	34
Assumed modulation	4-PSK	4-PSK	4-PSK	4-PSK	4-PSK
Thermal noise, KT (dBW/Hz)	-204	-204	-204	-204	-204
Receiver bandwidth, B (dBHz)	61.5	64.5	67.5	70.5	73.5
Receiver noise, KTB (dBW)	-142.5	-139.5	-136.5	-133.5	-130.5
Noise figure (dB) (NOTE 4)	9	9	9	9	9
S/N for BER = 10-6 without coding gain(dB) (NOTE 4)	13.5	13.5	13.5	13.5	13.5
S/N for BER = 10-6 with coding gain(dB) (NOTE 4)	-	-	-	-	-
Fixed systemlosses (dB) (NOTE 2)	4	4	4	4	4
Interference margin (dB) (NOTE 5)	2	2	2	2	2
Receiver sensitivity Level for BER = 10^-6 (dBW)	-114	-111	-108	-105	-102
Receiver sensitivity Level for BER = 10^-3 (dBW)	-119	-116	-113	-110	-107
Median receiver signal level (dBW) (NOTE 1)	-114 + M	-111 + M	-108 + M	-105 + M	-102 + M
Planned co-channel interference limit (dBW)	-139	-136	-133	-130	-127
NOTE 1: M is fade margin, dependent on path length, polarisation and availability required. NOTE 2: Includes demodulation losses, other implementation factors and branching network losses for single channel to points C, C'. NOTE 3: Referenced to point C. NOTE 4: Reference ITU-R Recommendation F.1101. All S/N values refer to average carrier power. NOTE 5: Minimum allowable N/I = 3 dB. (Reference points are those given in EN 300 431).

Table A.1: Example noise budget and interference calculations for Class 2 digital systems.

Channel bandwidth (MHz)	3.5	7	14	14	28	56
Minimum bit rate (Mbit/s)	8	2 x 8	34	51	51	140/155
Assumed modulation	16-QAM	16-QAM	16-QAM	16-QAM	16-QAM	16-QAM
Thermal noise, KT (dBW/Hz)	-204	-204	-204	-204	-204	-204
Receiver bandwidth, B (dBHz)	65.4	68.4	71	71.4	72.5	77.5
Receiver noise, KTB (dBW)	-138.6	-135.6	-133	-132.6	-131.5	-126.5
Noise figure (dB) (NOTE 3)	9	9	9	9	7	7
S/N for BER = 10^-6 without coding gain (dB) (NOTE 4)	20.5	20.5	20.5	-	20.5	20.5
S/N for BER = 10^-6 with coding gain (dB) (NOTE 4)	17.6	17.6	17.6	20.6	17.6	17.6
Fixed System Losses (dB) (NOTE 2)	4	4	4	4	4	4
Interference margin (dB) (NOTE 5)	2	2	2	2	2	2
Receiver sensitivity level for BER = 10^-6 (dBW)	-106	-103	-101	-97	-101	-96
Receiver sensitivity level for BER = 10^-3 (dBW)	-111	-108	-106	-100	-106	-101
Median receiversignal level (dBW) (NOTE 1)	-106 + M	-103 + M	-101 + M	-97 + M	-101 + M	-96 + M
Planned co-channel Interference Limit (dBW)	-135	-132	-130	-129	-134	-129
NOTE 1: M is fade margin, dependent on path length, polarisation and availability required. NOTE 2: Includes demodulation losses, other implementation factors and branching network losses for single channel to points C, C'. NOTE 3: Referenced to point C. NOTE 4: Reference ITU-R Recommendation F.1101. All S/N values refer to average carrier power. NOTE 5: Minimum allowable N/I = 3 dB. (Reference points are those given in EN 300 431).

Table A.2: Example noise budget and interference calculations for Class 4 digital systems.

Channel bandwidth (MHz)	28	56
Minimum bit rate (Mbit/s)	140/155	311
Assumed modulation	128-TCM	128-TCM
Thermal noise, KT (dBW/Hz)	-204	-204
Receiver bandwidth, B (dBHz)	74	77
Receiver noise, KTB (dBW)	-130	-127
Noise figure (dB) (NOTE 3)	9	9
S/N for BER = 10^-6 with coding gain (dB) (NOTE 4)	24	24
Fixed System Losses (dB) (NOTE 2)	4	4
Interference margin (dB) (NOTE 5)	2	2
Receiver sensitivity level for BER = 10^-6 (dBW)	-91	-88
Receiver sensitivity level for BER = 10^-3 (dBW)	-94	-91
Median receiversignal level (dBW) (NOTE 1)	-91 + M	-88 + M
Planned co-channel Interference Limit (dBW)	-127	-129
NOTE 1: M is fade margin, dependent on path length, polarisation and availability required. NOTE 2: Includes demodulation losses, other implementation factors and branching network losses for single channel to points C, C'. NOTE 3: Referenced to point C. NOTE 4: Reference ITU-R Recommendation F.1101. All S/N values refer to average carrier power. NOTE 5: Minimum allowable N/I = 3 dB. (Reference points are those given in EN 300 431 and EN 302 062).

Table A.3: Example noise budget and interference calculations for Class 5 digital systems.

Annex B: Wanted to Unwanted Levels

Tables B.1 to B.15 give the W/U ratios, in dB, for all licensable channel bandwidths up to three times (and, in a minority of cases, beyond three times) the mean value of the sum of the wanted and unwanted channel spacing (3XS).

The figures in the Annex B tables have been derived on the following basis: