10 Scenario 10.1 Setting the scenario A typical scenario consists of one victim link which describes the communication system being interfered and at least one interfering link which describes the interfering system(s) that may cause interference to the victim link. CDMA or OFDMA systems are modeled differently, using special algorithm that creates a grid of multiple cells.   Set the scenario by selecting what system will be the victim and what system will be the interferer. Remember that setting the frequency at the “scenario level” overwrite any settings at the “System level”.  Figure 209: Setting the simulation scenario     Table 40: Simulation scenario – Victim System Description Symbol Type Unit Comments Frequency f VLT or f ILT Distribution or Scalar MHz Distribution of the centre frequency of the victim system or the interfering system links.            The simulation control is explained in Section ‎2.10. 10.2 Multiple Interferers generation You have 3 options to generate multiple interferers in SEAMCAT. 10.2.1 Generation of multiple interferer links with different systems This option allows SEAMCAT to generate multiple interferers which may have the same or different technical characteristics from each other.  The following menu buttons are available in the interfering system links control panel. Add an interfering systems link to the scenario   Generate multiple interfering links Duplicate an interfering link Change the selected system type   Delete a link   On-line manual help Figure 210: Interfering system links control   Figure 211: Generation of multiple interferer links with different technical characteristics from each other   The feature “to position with” allows the deployment of a second type of interferer (for instance interfering link 1) for which the transmitters will be located at the same location as the transmitters of another type of interferers (i.e. interfering link 2 or interfering link 3). This feature is of interest since it allows deploying these two interferers at the same location (i.e. with the same coordinates) and these two transmitters could be transmitting at the same time while having different transmitter characteristics (e.g. emission mask, antenna radiation pattern…) or with a relative X, Y position set by DeltaX and DeltaY.    Figure 212: Possibility to position interferer links with one another   If for one interfering link (e.g. interfering link 1) the number of active transmitter is one, then for any extra interfering links, only one Tx is simulated. When the “to position with” feature is selected, any values are grey shaded and only one transmitter is simulated.    10.2.2 Auto-generation of multiple interfering links This option corresponds to duplicate n times a specific interfering links on a circle or on a hexagonal grid as illustrated below in (a) and (b) respectively. It is available by clicking on (    ). These interferers have the same characteristics as the reference interfering link. It has the purpose of automatically generating a regular pattern of interfering links. Figure 213: (a) Circular and (b) hexagonal layout Figure 214: Auto-generation of multiple interfering links   The multiple generate feature graphical interface consists of 3 parts: Selection of the reference interferer Relative position of this reference interferer to the victim link Layout preview of the new interferers   (a) Selection of the reference interferer You can choose an interfering link that will be used to clone the new interferers.  Figure 215: Selection of the reference interferers In the Generate Multiple Interfering Link dialog box, when selecting ok, 6 new interferers will now be present in the workspace, centered to the selected interferer (i.e. interfering link 1).  Figure 216: Generated new interferes, centered on interfering link 1   (b) Relative position of this reference interfere to the victim link You can adjust the position of the interferers with respect to either the VLT (Victim link transmitter) or the VLR (Victim link receiver). When the generate multiple feature is run the relative positioning of interfering link mode (i.e. in the victim receiver to interfering transmitter path tab) is by default overwritten. In this case the center of the interferers is set to (1,1) to VLT. Figure 217: Relative position of the interferer to the VLR or VLT   (c) Layout preview of the new interferes As a results the preview will display the following illustration Figure 218: Layout preview of the relative position of the interferer to the VLR or VLT   In the appearing dialog window, you may select the parameters described in .   Table 41: Generate Multiple Interfering Link GUI input parameters Description Symbol Type Unit Comments Circular or hexagonal layout - - - General circular or hexagonal layout Number of tiers of generated multiple cells - Scalar - You can generate as many tiers as you want Number of links in the first tier - Scalar - You can set the total number of links in the first tier Intersite distance D Scalar Km Distance between 2 BSs Displacement angle θ Scalar Degree Angle between the horizontal and the first BS (counter clockwise) Angle offset   Scalar Degree Angle offset of the displacement angle (d) Illustrative example of the generation of multiple interfering link The below figure shows an example of scenario that may be used for estimating intra‐service interference to a victim base station of cellular system from mobile transmitters operating in the next tier of co‐channel cells of the same system. The displacement angle is calculated automatically by the dialogue window by evenly spacing the specified number of cells around the 360 deg arc, but you may amend this angle. e.g. in order to achieve placement of multiple cells in a sector of less than 360 deg. The parameter angle offset may be used to specify the offset of an azimuth towards the first interfering cell with regard to the x‐axis, as seen from the centre cell. During the multiple link generation, the intersite distance parameter (0.433 km in the example), in combination with the specified initial offset angle, will overwrite the original coordinates (Delta X/DeltaY) in the Vr‐It path tab setting of the Interfering links. Figure 219: Example where 1 tier is used to position 4 interferers in a square shape (i.e. corners of a building) with the Vr positioned outside the square     10.2.3 Generation of interferers with the same characteristics Within one interfering link, you can define a number of active interfering transmitters when the mode "None" or "Uniform density" is selected. These active transmitters have the same technical characteristics (i.e. a simple duplicate) and they are deployed spatially independently according to the mode selected. The iRSS result is stored as one vector (of size number of events) where for each event the iRSS value is the simple power summation of the number of active transmitters. The number of active transmitters is directly used to compute the simulation radius (see Annex ‎A13.2).    Figure 220: Generation of multiple interferers with the same characteristics and using a specific deployment mode 10.3 Interfering Link Transmitter to Victim Link Receiver Path (ILT -> VLR) introduction The ILT to VLR path can have several combinations as shown in Figure 224. Four panels characterised the path between the ILT and ILR .  Figure 221: ILT to VLR path combination with generic and cellular system   Figure 222: Transmitter to Victim Link Receiver Path ( ILT -> VLR ) 10.3.1 Relative positioning of interfering link (Generic system) The relative position of the Victim Receiver ( VLR ) and the Interfering Transmitter ( ILT ) depends on the various options presented below. There is a unique simulation radius (R simu ) contrary to the 2 coverage radius (one for the victim and one for the interferer link). This is illustrated below in Figure 223 for a generic system interfering with a second generic system. See ‎ANNEX 12: for further details on the algorithm and conventions.  Figure 223: Example of the simulation radius ( VLR with ILT )   Depending on the system simulated several positioning options are possible when the generic system is the interferer and the victim is a generic system and cellular system as shown in Figure 224 and Figure 227 respectively.   Figure 224: Relative positioning of a generic interfering link with a generic victim system   Each interfering signal calculation results from the contribution of None : n active interefering link transmitters located in a circular area with the simulation radius. You define yourself the radius. The random placement of the interefering link transmitters in this area is defined by the path azimuth and the path distance factor parameters. See Annex ‎A13.2.1 for detailed algorithm.   Table 42: ILT - VLR path - none mode (generic vs generic) Description Symbol Type Unit Comments Reference component -   - Positioning of the distributed component which is either the ILT or the ILR   Position relative to -   - Positioning of the reference component relative to either the VLR or the VLT Delta X ∆X Distribution or Scalar km Horizontal distance between the transmitter and receiver. It can be used to shift horizontally the distributed receivers Delta Y ∆Y Distribution or Scalar km Vertical distance between the transmitter and receiver. It can be used to shift vertically the distributed receivers Set ILR at he center of the ILT distribution - Boolean - set the distance factor distribution of the ILT with regards to the VLR . It overwrites the settings in the transmitter to reveicer path of the interferer Path azimuth   Distribution or Scalar Deg Horizontal angle for the location of the ILT respect to the victim link. If constant, the Rx’s location will be on a straight line. If not, the location of the Rx will be on an angular area. (See Annex ‎A12.3) Path distance factor   Distribution or Scalar     Distance factor to describe path length between the ILT and VLR . This factor will be multiplied by R simu to obtain the coverage area. Therefore, the trialled distance between ILT and VLR will be R simu *Path factor. E.g. if user enters a distribution 0…1, then the distance will be between 0 and R simu . If the path factor is constant, the ILT will be located on a circle around the VLR which means that the distance between the ILT and VLR will not change Simulation radius R simu   km User defined Number of active transmitter n active Scalar   If n active >1, this will result in spatially-independent generation of the specified number of Its, whereas the resulting total iRSS strength will be obtained by simple power summation of the individual iRSS signal values. Minimum coupling loss MCL Distribution or Scalar dB The minimum path loss. It is used in the calculation of the effective path loss (Section ‎7.6) Protection distance d0 Distribution or Scalar (km) minimum protection distance  between the victim link receiver and interefering link transmitter (Section ‎A13.2.3) Use of polygon       You are also able to select a polygon shape as an alternative to the default circle. A various selection of polygon is available. You are able to rotate counter-clock wise (ccw) the polygon shape. Co-locate       This feature allows deploying two interferers at the same location and their two transmitters could be transmitting at the same time while having different transmitter characteristics (e.g. emission mask, antenna radiation pattern…) Uniform density : Each interfering signal calculation results from the contribution of n active interefering link transmitters uniformly located in a circular area. The parameters are taken from the system settings (see section A13.2.2.)     Figure 225: Transmitter density and traffic   Table 43: ILT - VLR path - Uniform density mode (generic vs generic) Description Symbol Type Unit Comments Reference component -   - Positioning of the distributed component which is either the ILT or the ILR   Position relative to - Boolean - Positioning of the Reference component relative to either the VLR or the VLT Delta X ∆X Distribution or Scalar km Horizontal distance between the transmitter and receiver. It can be used to shift horizontally the distributed receivers. Delta Y ∆Y Distribution or Scalar km Vertical distance between the transmitter and receiver. It can be used to shift vertically the distributed receivers. set ILR at he center of the ILT distribution - Boolean - Set the distance factor distribution of the ILT with regards to the VLR . It overwrites the settings in the transmitter to reveicer path of the interferer. Path azimuth   Distribution or Scalar Deg Horizontal angle for the location of the ILT respect to the victim link. If constant, the Rx’s location will be on a straight line. If not, the location of the Rx will be on an angular area. (See Annex ‎A12.3) Number of active transmitter nactive Scalar   Number of active interferers in the simulation (nactive should be sufficiently large so that the (n+1)th interferer would bring a negligible additional interfering power). If n active >1, this will result in spatially-independent generation of the specified number of Its, whereas the resulting total iRSS strength will be obtained by simple power summation of the individual iRSS signal values. Simulation radius   R simu   km Note: the simulation radius value is readable only after each simulation Interferes density         A simulation radius is calculated, R simu . Interefering link transmitters will be randomly deployed within the area centred on the Victim link receiver and delimited by the simulation radius R simu . If a protection is defined then Interefering link transmitters will be randomly deployed within the area centred in the Victim link receiver and delimited by the protection distance and the simulation radius R simu . See Table 46 for information on the input parameter and Annex ‎A13.2.2 for the calculation. Minimum coupling loss MCL Distribution or Scalar dB The minimum path loss. It is used in the calculation of the effective path loss (Section ‎7.6) Protection distance d0 Scalar (km) Minimum protection distance  between the victim link receiver and interefering link transmitter (Section ‎A13.2.3) Co-locate       This feature allows deploying two interferers at the same location and their two transmitters could be transmitting at the same time while having different transmitter characteristics (e.g. emission mask, antenna radiation pattern…) Closest interferer : Each interfering signal calculation results from the contribution of just one interefering link transmitter . This ILT is randomly placed in a circular area with a simulation radius derived from the density of interferers. See Annex ‎A13.2.4 for detailed alogorithm. The parameters are taken from the system settings (see section A13.2.4). Figure 226: Transmitter density and traffic   Table 44: ILT - VLR path - Closest interferer mode (generic vs generic) Description Symbol Type Unit Comments Reference component -   - Positioning of the distributed component which is either the ILT or the ILR   Position relative to - - - Positioning of the Reference component relative to either the VLR or the VLT Delta X ∆X Distribution or Scalar km Horizontal distance between the transmitter and receiver. It can be used to shift horizontally the distributed receivers Delta Y ∆Y Distribution or Scalar km Vertical distance between the transmitter and receiver. It can be used to shift vertically the distributed receivers Set ILR at he center of the ILT distribution - Boolean - Set the distance factor distribution of the ILT with regards to the VLR . It overwrites the settings in the transmitter to reveicer path of the interferer Path azimuth   Distribution or Scalar Deg Horizontal angle for the location of the ILT respect to the victim link. If constant, the Rx’s location will be on a straight line. If not, the location of the Rx will be on an angular area. (See Annex ‎A1.1) Number of active transmitter nactive Scalar   Number of active interferers in the simulation (nactive should be sufficiently large so that the (n+1)th interferer would bring a negligible additional interfering power). If n active >1, this will result in spatially-independent generation of the specified number of Its, whereas the resulting total iRSS strength will be obtained by simple power summation of the individual iRSS signal values Simulation radius   R simu   km Note: the simulation radius value is readable only after each simulation Interferes density         The distance between the Victim link receiver and the Interefering link transmitter follows a Rayleigh distribution, where the standard deviation is given by . See Table 47 for information on the input parameter and Annex  ‎A13.2.4 for the calculation Minimum coupling loss MCL Distribution or Scalar dB The minimum path loss. It is used in the calculation of the effective path loss (Section ‎7.6) Protection distance d0 Scalar (km) minimum protection distance  between the victim link receiver and interefering link transmitter (Section ‎A13.2.3) Co-locate       This feature allows deploying two interferers at the same location and their two transmitters could be transmitting at the same time while having different transmitter characteristics (e.g. emission mask, antenna radiation pattern…) Correlated : It is called the correlated mode. It means that the positions of the receiver and transmitter are geographically fixed with respect to each other (e.g. co-located or constantly spaced base stations). In the following four cases of fixed placement, the relative location of the two pair of transmitter and receiver is described by dX/dY displacement, with the origin being either on the Transmitter or Receiver of the victim link depending on the option selected; Table 45: ILT - VLR path – Correlated mode (generic vs generic) Description Symbol Type Unit Comments Reference component -   - Positioning of the distributed component which is either the ILT or the ILR   Position relative to - B - Positioning of the fixed interefer transmitter ( ILT ) or receiver ( ILR ) with the origin being. Reference component relative to either onthe VLR or the victim link transmitter (VLT) or receiver ( VLR ) on the option selected. Delta X ∆X Distribution or Scalar km Horizontal distance between the transmitter and receiver. It can be used to shift horizontally the distributed receivers. Delta Y ∆Y Distribution or Scalar km Vertical distance between the transmitter and receiver. It can be used to shift vertically the distributed receivers. Minimum coupling loss MCL Distribution or Scalar dB The minimum path loss. It is used in the calculation of the effective path loss (Section ‎7.6) In the case the victim system is a cellular system ( CDMA or OFDMA , either UL or DL), the options are slightly changed as shown below, where Position relative to is always the BS of the reference cell. Figure 227: Relative positioning of a generic interfering link with a cellular victim system   10.3.2 Relative positioning of interfering link (Cellular system) The relative position of the Victim Receiver ( VLR ) and the Interfering cellular system depends on the various options presented below.  Figure 228: Relative positioning of a cellular interfering link with a generic victim system Cor. (interfering BS ref. cell): in which case the relative location is explicitely defined by the dX/dY values given in the scenario and the reference is the BS ref.cell. It is a similar mode as described in Table 43 where the BS ref.cell of the cellular interferer is position with respect to the VLT or VLR depending on the selection; Dyn (interfering BS ref.cell): this dynamic distance mode provides a a relative location that follows a uniform distribution in the distance and angle domain.   Table 46:  ILT - VLR path – Correlated mode (cellular vs generic) Description Symbol Type Unit Comments Position relative to VLT or VLR - Boolean - Positioning of the fixed interefer transmitter ( ILT ) or receiver ( ILR ) with the origin being either on the victim link transmitter ( VLT ) or receiver ( VLR ) on the option selected. Delta X ∆X Distribution or Scalar km Horizontal distance between the transmitter and receiver. It can be used to shift horizontally the distributed receivers. Delta Y ∆Y Distribution or Scalar km Vertical distance between the transmitter and receiver. It can be used to shift vertically the distributed receivers. Path azimuth - Distribution or Scalar Deg Horizontal angle for the location of the interfering BS ref.cell respect to the VLR or VLT Path distance - Distribution or Scalar km   Path length between the interfering BS ref.cell respect to the VLR or VLT Minimum coupling loss MCL Distribution or Scalar dB The minimum path loss. It is used in the calculation of the effective path loss (Section ‎7.6) Figure 229: Relative positioning of a cellular interfering link with a cellular victim system   Cor. (victim BS ref.cell à interfering BS ref.cell): It is the same mode as described in Table 45 but where the BS of the reference cell of the victim cellular network is the reference position of the BS of the reference cell of the interfering cellular network. Dyn. (victim BS ref.cell à interfering BS ref.cell): It is the same mode as described in Table 48, but where the BS of the reference cell of the victim cellular network is the reference position of the BS of the reference cell of the interfering cellular network. 10.3.3 Interferers density The panel is activated if "Uniform density" or/and "closest interferer" mode is selected. See Annex ‎A13.2.2 for more details on the calculation. Figure 230: Interferers density panel (only in "Uniform density" and "closest interferer” mode)   Table 47: Setting up the interferes density Description Symbol Type Unit Comments Density of transmitters dens it Scalar 1/km 2 Maximum number of active transmitters per km 2 Probability of transmission P it Scalar %   Activity activity it Function (X,Y) 1/h Temporal activity variation as a function of the time of the day (hh/mm/ss) Time time Scalar hour Time of the day. If the activity function (above), here it should be specified which hour (from the defined range of function) should be considered in a simulation 10.3.4 Pathloss correlation The panel is activated if the victim is either OFDMA UL or OFDMA DL. It is decribed in more details in Section ‎9.11. 10.3.5 Propagation Model You can choose the suitable propagation model to be applied when calculating signal loss between the ILT and the VLR . A choice and settings of propagation models are presented in ‎ANNEX 17:.  10.4 Interfering link transmitter to victim link transmitter path (spectrum sensing) 10.4.1 Spectrum sensing characteristics When the spectrum sensing is activated, the tab “Interfering link transmitter to victim link transmitter path” will become editable (#1 of Figure 231) and you can set the input parameters of the CR algorithm (#2). Note that the frequency of the interferer is disabled (#3). The purpose of the CR algorithm in SEAMCAT automatically calculates the number of possible channels the WSD will operate in based on the operating frequency range of the victim system and its victim link receiver bandwidth (#4). You can not simulate “ OFDMA / CDMA ” as a victim and have a CR interferer. The implementation only considers generic versus generic Figure 231: Example of the Cognitive Radio GUI selection - Input settings When an interferer is set as a CR , the emission characteristics (i.e. transmitted power, emission mask and unwanted emission mask) have to be entered (see Section ‎6.3) and the spectrum sensing characteristics presented in Figure 232 have to be entered.  Figure 232: Setting the spectrum sensing characteristics in the Victim link transmitter to Interefering link transmitter Path   Table 48: Spectrum sensing characteristics Description Symbol Type Unit Comments Detection threshold:   Function (X,Y) or Scalar (offset) dBm Define the detection threshold for the spectrum sensing in a offset function. Either a constant value (i.e. flat over the spectrum) or as a user defined function as shown in #1 of Figure 232 illustrates the setting of the detection threshold (a) as a constant or (b) as a function. Figure 233 (c) illustrates where the offset refers to. Note the user-defined function is defined as offset with the victim frequency being the reference. The offset  0 is refered to the Victim frequency. Probability of failure:   Scalar % You can select this function as shown in #2 of Figure 232. The probability of failure is given in percentage. In the illustration below a probability of failure of 10% is entered. Positive value from 0 to 100. Sensing reception bandwidth   Scalar kHz Define the bandwidth of the sensing device (i.e. ILT ). It is used in the calculation of the sRSS: This is a constant value given in kHz as shown in #3 of Figure 232. e.i.r.p. max In-block limit   Function (X,Y) (offset) Offset (MHz)/ Mask (dBm)/ Ref. BW (kHz) Define the E.I.R.Pmax In-block limit to protect the victim system as an offset function where the offset  0 is refered to the selected interfering frequency. The outcome of the algorithm set the allowed power at the ILT . It has the following components [offset, Mask, Ref. BW ] where Offset in MHz is equivalent to the “ DTT in use at” columns, Mask in dBm is the “In-block CR EIRP max limit” and Ref. BW is the bandwidth of the DTT as shown in #4 of Figure 232. Note that SEAMCAT will normalise any value entered in the table to 1 MHz and convert back to the victim bandwidth. 10.4.2 Detection of threshold In relation to the spectrum sensing results, if this CR detect that a victim system is in the vicinity it will select an appropriate operating frequency and it will lower its emission based on an e.i.r.p. max in block limit defined in the spectrum sensing characteristics. Figure 233 presents an example of the detection threshold (a) as a constant or (b) as a function and illustrates in (c) where the offset refers to and its evolution from event to event. (a) (b) (c) Figure 233: Example of the detection threshold (a) as a constant or (b) as a function and illustrates in (c) where the offset refers to 10.4.3 Probability of failure This feature is input selectable (by default, it is de-activated).The probability of failure may account for the failure in selecting wrongly a non_available channel for one event. This means that when a failure appears, a channel which was initially selected as occupied by a victim DTT becomes “wrongly” available for the WSD to transmit. This results in a “conflict” situation. For instance with a defined p failure , that means that for x total of WSD (initial input to SEAMCAT) there is x*p failure WSDs which will transmit in the victim frequency without power constraint. p failure is an input parameter. 10.4.4 Adjacent channel scenario - e.i.r.p. max. in-block limit In the case where the WSDs are not allowed to transmit in the same operating frequency as for the victim DTT device, the WSDs can decide to transmit in the adjacent bands or channels. This scenario is illustrated in Figure 234 In this example the WSDs have sensed that in the channel 6 there is a victim system (here a DTT ), therefore the WSDs will choose other channels to transmit. The maximum permitted in-block and out-of-block e.i.r.p. of autonomous CRs would be specified as a function of the guard band with respect to DTT channels used in the local proximity of the CR . The available guard band would be identified by comparison of the detected DTT signal powers against a fixed detection threshold .  Figure 234: Illustration of  WSD1 detecting a victim device in channel 6 and as a consequence decides to operate in channel 3 which is available The purpose of the SEAMCAT simulation is to investigate the level of interference created by WSDs to the DTT victim device. Therefore the iRSS unwanted and iRSS blocking for a WSD will be computed. As a reminder, the e.i.r.p. (Equivalent isotropically radiated power) is defined as:       (Eq. 66) where  L c is the cable loss in dB. We will neglect L c . Extract the Tx power = e.i.r.p. max - G maxIt→ VLR and calculate the iRSS unwanted and the iRSS blocking from the WSD to the victim DTT device. As a result, the interference calculation can be performed on the summation of the iRSS unwanted per channel and iRSS blocking per channel in the case where there are multiple active WSDs per channel. The determination of the e.i.r.p. max in-block limit is illustrated in Annex ‎A16.2. An example of In-block input values (dBm), is presented in Table 49 and Figure 235 illustrates how to set this parameter in SEAMCAT.   Table 49: Example of In-block CR e.i.r.p. max. emission limits as a function of guard band with respect to a victim DTT with channel bandwidth of 8 MHz (source SE43 (10)18) DTT in use at In-block CR e.i.r.p. max limit (dBm) co-channel -¥¥ n ± 1 -12.8 n ± 2 3.2 n ± 3 11.2 n ± 4 16.2 n ± 5 20.2 n - 6 16.2 n + 6 21.2 n ± 7 22.2 n ± 8 23.2 n - 9 4.2 n + 9 23.2 n ± 10 24.2 > n ± 11 25.2   Figure 235: GUI of the In-block CR e.i.r.p. max limit (dBm)       10.4.5 Propagation Model You can choose the suitable propagation model to be applied when calculating signal loss along the transmitter and the receiver path. A choice and settings of propagation models are presented in ‎ANNEX 17:.