ARE STAR CONTRIBUTION NETWORKS MORE BANDWIDTH EFFICIENT THAN MESH NETWORKS?

ARE STAR CONTRIBUTION NETWORKS MORE BANDWIDTH EFFICIENT THAN MESH NETWORKS? Dirk Breynaert, Newtec 04 Augustus 2005 Abstract The article is mainly investigating the satellite bandwidth efficiency of MESH and STAR networks in the Contribution & Exchange DTV market, not so much other advantages or disadvantages. As a reference, 2 types of satellite uplink contours are considered : Type 1 - Ku-band with regional coverage (e.g. Europe) and Type 2 - Ku SPOT coverage (e.g. Europe is covered with 4 spots). The downlink contour is always considered to be with regional coverage. MESH Networks are only using Type 1, while STAR Networks can use Type 1 & Type 2. Although STAR Networks links require a double hop and as such require twice satellite bandwidth, the conclusion is that at the end these are slightly requiring less satellite bandwidth than MESH Networks for the same size of contribution or exchange earth stations. Introduction In general, MESH link have balanced up & downlink. Each contributing 3 db to the total link performance. In case a big HUB station would be used in between, a simple model would be that, power bandwidth product would be 3 db higher, resulting in 1.5 db or factor 1.41 capacity increase. Due to the fact that however 2 links are required in STAR (inbound + outbound) and 1 link in MESH, this would mean that efficiency of STAR would be 71% of MESH Networks. However, two factors can play an important role in this comparison. In STAR Networks, the uplink & downlink are largely decoupled and the carrier intermodulation effect in the satellite is negligible ; so that in inbound, less system margin is required. Another effect is that in STAR outbound, a quasi saturated carrier can be used. Both effects are calculated in more detail hereafter and they result in a conclusion that STAR Networks are more satellite bandwidth efficient than MESH Networks. MESH Network over Regional Contours a) Satellite The Conventional satellites for regional usage are e.g. covering Europe (e.g. EUTELSAT) or the Middle East & North Africa (e.g. ARABSAT) regions in the Ku-band. Typical transponder characteristics are EIRP SAT 47.5 dbw, G/T 2 db/k and 36 MHz band. For multicarrier operation, typical parameters are GIBO 9 db, GOBO 4 db and CAR/INTERMOD 20 db. b) Earth Stations For contribution links, antenna diameters of max. 1.8 meter seems to be suitable. For specific DSNG applications, 1.2 meter is more recommended. Since often, at least a second carrier is used for general communication, a typical SSPA size for a 4 Mbps - video link is 20 Watt with 2 db OBO ; G/T = 23.6 db/k. An availability of 99.95% is used as a typical reference. 1

c) Link budget of MESH Link MESH connections require that the uplink and downlink are more or less balanced. However, if there is a fading at the uplink stations, all receive stations will feel the effect. In case of multicast contribution, there is also a risk that there is a reasonable probability that at least 1 receive station is also experiencing a simultaneous downlink fade. For that reason, a system margin of 4 db has been used in the link budget calculations (shown in Table 1). The outcome is that 4 Mbps requires a DVB-S2 carrier with QPSK 2/3 and Ebi/No = 2.3 db (*). The transponder supports up to 9.05 carriers of 4 Mbps or 36.2 Mbps in total. As said, this requires that the transponder gain setting is tuned to a balanced up and downlink. In case only a part of the transponder is rented, the up or downlink would be dominating and this would result in less efficient bandwidth use. In case of an earth station uplink fade, it will not be possible anymore to receive it's own transmission due to on-site downlink fade. Also stations in the close neighbourhood (± 30 km) will experience such problem. This could be very annoying in case of a 1.8 meter DSNG truck close to a 1.8 meter studio station. Another disadvantage is that in case of a mix of receive station antennas, it will not be possible to send occasionally to a smaller earth station than 1.8 meter, e.g. a 1.2 meter Fly Away cannot see it's own transmission. STAR Network over Regional Contours a) Satellite A similar satellite than for the above described MESH network is considered hereafter. Since the downlink is received by a big HUB station, more transponder back-off can be allowed. GIBO 11 db GOBO 6 db CAR/INTERMOD 22 db. b) Contribution Stations Similar earth stations as for MESH are assumed. Antenna : 1.8 meter SSPA : 20 Watt with OBO = 2 db G/T : 23.6 db/k c) HUB Stations A large HUB station in a not heavy rain area is chosen. Antenna : 8.0 meter HPA : 200 Watt with OBO = 2 db G/T : 36.5 db/k d) Link budget of STAR inbound link It is assumed that availability of the uplink is 99.95% and of the downlink is 99.99% (negligible). In fact the dominating factor is the EIRP of the earth station and the G/T of the satellite. If adjacent stations are sending out at higher levels than normal, this will not effect the link budget. Level variation in the inbound has no impact on the outbound. Also intermod in the satellite is more negligible than in the MESH network. As a consequence, a system margin of 2 db is considered as sufficient. The outcome is that 4 Mbps requires a DVB-S2 carrier with 16 APSK 2/3 and Ebi/No = 5.6 db (see Table 2) (*). The transponder supports up to 17.91 carriers of 4 Mbps or 71.65 Mbps in total. This is about the double of the MESH network. e) Link budget of STAR outbound link It is assumed that availability of the uplink is 99.99% (negligible) and of the downlink is 99.95%. In fact the dominating factor is the EIRP of the satellite and the G/T of the receive station. The transponder will however be used via ALC mode and close to saturation IBO = 3.8 db, OBO = 1.6 db to allow single carrier 16APSK transmission. (*) See Application Note NTC/2063xF/APN02 2

The DVB-S2 carrier can use 16 APSK with small predistortion realising only a link degradation of 0.5 db. This is a very stable concept and is used for the normal TV broadcasting stations. It is therefore sufficient to foresee a system margin of 2 + 0.5 = 2.5 db. The outcome is that a full transponder allows to send 74.745 Mbps as a DVB-S2 16APSK 2/3 30 Mbaud carrier (see Table 3). It is however also possible to receive info by smaller stations e.g. 1.2 meter DSNG stations. In such as case, a less efficient MODCOD could be used. In case of a point-to-point link to 1 destination, it is also possible to activate the ACM (Adaptive Coding and Modulation) mode in 16APSK 8/9 allowing 100.245 Mbps to be send over a 30 Mbaud carrier. f) Combination of inbound + outbound link In this case, it is also possible to have an uplink fade in the inbound and a simultaneous downlink fade in the outbound. The total link will still be OK Compared to the MESH concept, the transponder efficiency is better since capacity is (71.65 + 74.745)/2 = 73.2 Mbps. However since 2 links are required instead of the MESH 1 link, the net result is 73.2/2 = 36.6 Mbps ; which is only 1% higher than the full MESH concept. STAR Network using Spot Inbound and Regional Outbound contour b) Contribution Stations Similar as full Regional Contour concept, except that a lower power SSPA can be used. Antenna : 1.8 meter SSPA : 8 Watt with OBO = 2 db G/T : 23.6 db/k c) HUB Stations Similar as full Regional Contour config except that lower power SSPA can be used. HPA : 50 Watt with OBO = 2 db G/T : 36.5 db/k d) Link budget of STAR inbound link Compared to the full Regional Contour Concept, the SSPA is 4 db less ; G/T of satellite is 6 db higher. The outcome is that 4 Mbps requires a DVB-S2 carrier with 16APSK 3/4 and Ebi/No = 6.0 db (see Table 4). The transponder supports up to 19.67 carriers of 4 Mbps or 78.68 Mbps. e) Link budget of STAR outbound link Same as the STAR full Regional Contour Concept. f) Combination of inbound + outbound link The average efficiency is (78.68 + 74.745)/2 = 76.7 Mbps. However since 2 links are required instead of the MESH 1 link, the net result is 76.7/2 = 38.4 Mbps ; which is only 6% higher than the full MESH concept. However the contribution stations only require 8 Watt instead of 20 Watt. a) Satellite Such satellite are typically used in Broadband Access Applications (e.g. Eutelsat AB3). The main difference with the earlier described full regional contour is that the G/T of the satellite is typically around 8 db/k. The remaining characteristics are similar than before. 3

Conclusions (*) MESH Networks - They require a good control of the earth station EIRP levels and of the transponder gain settings. - They require also that there are no large variations in the antenna diameters. - They are very sensitive to simultaneous up & downlink fading events. (*) STAR networks in full regional contours - They are not very sensitive to earth station EIRP variation. - They allow a mix of different antenna sizes in inbound and outbound. - They are insensitive to simultaneous fading events at the contribution earth stations. - They allow better control of satellite usage via the HUB station. - They are at least 1% more efficient than MESH. - Due to double hop, they have higher end-to-end delay. (*) STAR networks with inbound spot customers and outbound regional contours - Same conclusions as STAR full regional contour concept, except that the powers in the contribution station and in the HUB station can be significantly reduce. - They are at least 6% more efficient than MESH networks. About Newtec and the author Newtec is a leading SATCOM supplier for Broadband Access Networks, for Professional SATCOM systems and for itv Solutions. Dirk Breynaert is one of the founders and CEO of Newtec Cy. Contact information : Tel : +32 3 780 65 00 Fax : +32 3 780 65 49 web : www.newtec.be 4

Table 1 : MESH Link Budget Digital Link Budget Produced using Satmaster Pro Thursday, August 04, 2005 Service Name ABx SCPC mesh Rom Rom 01 Q 2/3 Coverage 180cm interf-free,ntc,adj.chan=30db Uplink earth station Roma, Italy Downlink earth station Roma, Italy Satellite name ABx regional Link Input Parameters Uplink Downlink Units Site latitude 41.90N 41.90N degrees Site longitude 12.48E 12.48E degrees Site altitude 0 0 km Frequency 14.3401 11.0575 GHz Polarization Vertical Horizontal - Rain model ITU (41.4) ITU (41.4) (mm/h or zone) Availability (average year) 99.95 99.95 % Water vapour density 7.5 7.5 gm/m3 Surface temperature 15 15 C Antenna aperture 1.8 1.8 metres Antenna efficiency / gain 60 55 % (+ prefix dbi) Coupling loss 0.3 0. db Antenna tracking / mispoint error 0.3 0.3 db LNB noise figure / temp - 1 db (+ prefix K) Antenna noise - 30 K Adjacent carrier interference 30 40 db Adjacent satellite interference 35 40 db Cross polarization interference 35 40 db Uplink station HPA output back-off 2 - db Number of carriers / HPA 1 - - HPA C/IM (up) 200 - db Uplink power control 0 - db Uplink filter truncation loss 0 - db Required HPA power capability 20 - W Satellite Input Parameters Value Units Satellite longitude 5.00W degrees Transponder type TWTA - Receive G/T 2 db/k Saturation flux density -87.5 dbw/m2 Satellite attenuator pad 0 db Satellite ALC 0 db EIRP (saturation) 47.5 dbw Transponder bandwidth 36 MHz Input back off total 9 db Output back off total 4 db Intermodulation interference 20 db Number of transponder carriers AUTO - 5

Carrier/Link Input Parameters Value Units Modulation 4-PSK - Required bit error rate performance 10^-5 - Required Eb/No without FEC coding 9.59 db Required Eb/No with FEC coding 2.3 db Information rate 4 Mbps Overhead 2.3 % FEC code rate 0.6442 - Spreading gain 0 db Reed Solomon code 1 - (1 + Roll off factor) 1.0 - Carrier spacing factor 1.25 - Bandwidth allocation step size 0.01 MHz System margin 4 db Calculations at Saturation Value Units Gain 1m^2 44.59 db/m2 Uplink C/No 98.51 db.hz Downlink C/No 94.09 db.hz Total C/No 92.75 db.hz Uplink EIRP for saturation 75.83 dbw General Calculations Uplink Downlink Units Elevation 38.44 38.44 degrees True azimuth 205.25 205.25 degrees Compass bearing 203.48 203.48 degrees Path distance to satellite 37901.17 37901.17 km Propagation time delay 0.126424 0.126424 seconds Antenna efficiency 60.00 55.00 % Antenna gain 46.42 43.79 dbi Availability (average year) 99.95 99.95 % Link downtime (average year) 4.383 4.383 hours Availability (worst month) 99.790 99.790 % Link downtime (worst month) 1.537 1.537 hours Spectral power density -54.31-31.08 dbw/hz Uplink Calculation Clear Rain Up Rain Dn Units Uplink transmit EIRP 57.13 57.13 57.13 dbw Transponder input back-off (total) 9.00 9.00 9.00 db Input back-off per carrier 18.56 22.40 18.56 db Mispoint loss 0.30 0.30 0.30 db Free space loss 207.15 207.15 207.15 db Atmospheric absorption 0.12 0.12 0.12 db Tropospheric scintillation fading 0.34 0.34 0.34 db Atmospheric losses total 0.46 0.46 0.46 db Total path loss (excluding rain) 207.91 207.91 207.91 db Rain attenuation 0.00 3.84 0.00 db Uplink power control 0.00 0.00 0.00 db Uncompensated rain fade 0.00 3.84 0.00 db C/No (thermal) 79.82 75.99 79.82 db.hz C/N (thermal) 14.80 10.97 14.80 db C/ACI 30.00 26.16 30.00 db C/ASI 35.00 31.16 35.00 db C/XPI 35.00 31.16 35.00 db C/IM 200.00 200.00 200.00 db Eb/(No+Io) 13.49 9.66 13.49 db 6

Downlink Calculation Clear Rain Up Rain Dn Units Satellite EIRP total 47.50 47.50 47.50 dbw Transponder output back-off (total) 4.00 4.00 4.00 db Output back-off per carrier 13.56 17.40 13.56 db Satellite EIRP per carrier 33.94 30.10 33.94 dbw Mispoint loss 0.30 0.30 0.30 db Free space loss 204.89 204.89 204.89 db Atmospheric absorption 0.09 0.09 0.09 db Tropospheric scintillation fading 0.30 0.30 0.30 db Atmospheric losses total 0.39 0.39 0.39 db Total path loss (excluding rain) 205.58 205.58 205.58 db Rain attenuation 0.00 0.00 2.19 db Noise increase due to precipitation 0.00 0.00 3.01 db Downlink degradation (DND) 0.00 0.00 5.20 db Total system noise 105.09 105.09 209.94 K Figure of merit (G/T) 23.57 23.57 20.57 db/k C/No (thermal) 80.53 76.69 75.33 db.hz C/N (thermal) 15.51 11.67 10.31 db C/ACI 40.00 36.16 40.00 db C/ASI 40.00 36.16 40.00 db C/XPI 40.00 36.16 40.00 db C/IM 20.00 16.16 20.00 db Eb/(No+Io) 13.05 9.22 8.76 db Totals per Carrier (End-to-End) Clear Rain Up Rain Dn Units C/No (thermal) 77.15 73.31 74.01 db.hz C/N (thermal) 12.13 8.30 8.99 db C/ACI 29.59 25.75 29.59 db C/ASI 33.81 29.97 33.81 db C/XPI 33.81 29.97 33.81 db C/IM 20.00 16.16 20.00 db C/(No+Io) 76.38 72.54 73.62 db.hz C/(N+I) 11.36 7.52 8.60 db Eb/(No+Io) 10.26 6.42 7.50 db System margin 4.00 4.00 4.00 db Net Eb/(No+Io) 6.26 2.42 3.50 db Required Eb/(No+Io) 2.30 2.30 2.30 db Excess margin 3.96 0.12 1.20 db Earth Station Power Requirements Value Units EIRP per carrier 57.13 dbw Antenna feed flange power per carrier 10.71 dbw Uplink power control 0.00 db HPA output back off 2.00 db Waveguide loss 0.3 db Filter truncation loss 0 db Number of HPA carriers 1 - Total HPA power required 13.0103 dbw Required HPA power capability 20.0000 W Spectral power density -54.31 dbw/hz 7

Space Segment Utilization Value Units Overall link availability 99.900 % Information rate (inc overhead) 4.0920 Mbps Transmit rate 6.3521 Mbps Symbol rate 3.1760 Mbaud Occupied bandwidth 3.1760 MHz Noise bandwidth 65.02 db.hz Minimum allocated bandwidth required 3.9700 MHz Allocated transponder bandwidth 3.9800 MHz Percentage transponder bandwidth used 11.06 % Used transponder power 33.94 dbw Percentage transponder power used 11.06 % Max carriers by transponder bandwidth 9.05 - Max carriers by transponder power 9.31 - Max transponder carriers limited by:- Bandwidth [9.05] 8

Table 2 : STAR Inbound Link Budget - Regional Contour Digital Link Budget Produced using Satmaster Pro Thursday, August 04, 2005 Service Name ABx-Reg SCPC star Rom Bru 01 16 2/3 Coverage 180cm interf-free,ntc,adj.chan=30db Uplink earth station Roma, Italy Downlink earth station Brussels, Belgium Satellite name ABx-regional Link Input Parameters Uplink Downlink Units Site latitude 41.90N 50.83N degrees Site longitude 12.48E 4.35E degrees Site altitude 0 0 km Frequency 14.3401 11.0575 GHz Polarization Vertical Horizontal - Rain model ITU (41.4) ITU (28.2) (mm/h or zone) Availability (average year) 99.95 99.99 % Water vapour density 7.5 7.5 gm/m3 Surface temperature 15 15 C Antenna aperture 1.8 8 metres Antenna efficiency / gain 60 55 % (+ prefix dbi) Coupling loss 0.3 0. db Antenna tracking / mispoint error 0.3 0.3 db LNB noise figure / temp - 1 db (+ prefix K) Antenna noise - 30 K Adjacent carrier interference 30 40 db Adjacent satellite interference 35 40 db Cross polarization interference 35 40 db Uplink station HPA output back-off 2 - db Number of carriers / HPA 1 - - HPA C/IM (up) 200 - db Uplink power control 0 - db Uplink filter truncation loss 0 - db Required HPA power capability 20 - W Satellite Input Parameters Value Units Satellite longitude 5.00W degrees Transponder type TWTA - Receive G/T 2 db/k Saturation flux density -79 dbw/m2 Satellite attenuator pad 0 db Satellite ALC 0 db EIRP (saturation) 47.5 dbw Transponder bandwidth 36 MHz Input back off total 14 db Output back off total 9 db Intermodulation interference 25 db Number of transponder carriers AUTO - 9

Carrier/Link Input Parameters Value Units Modulation 16-PSK - Required bit error rate performance 10^-5 - Required Eb/No without FEC coding 17.44 db Required Eb/No with FEC coding 5.6 db Information rate 4 Mbps Overhead 2.3 % FEC code rate 0.6372 - Spreading gain 0 db Reed Solomon code 1 - (1 + Roll off factor) 1.0 - Carrier spacing factor 1.25 - Bandwidth allocation step size 0.01 MHz System margin 2 db Calculations at Saturation Value Units Gain 1m^2 44.59 db/m2 Uplink C/No 107.01 db.hz Downlink C/No 106.85 db.hz Total C/No 103.92 db.hz Uplink EIRP for saturation 84.33 dbw General Calculations Uplink Downlink Units Elevation 38.44 31.13 degrees True azimuth 205.25 191.99 degrees Compass bearing 203.48 192.68 degrees Path distance to satellite 37901.17 38511.47 km Propagation time delay 0.126424 0.128460 seconds Antenna efficiency 60.00 55.00 % Antenna gain 46.42 56.75 dbi Availability (average year) 99.95 99.99 % Link downtime (average year) 4.383 0.877 hours Availability (worst month) 99.790 99.948 % Link downtime (worst month) 1.537 0.379 hours Spectral power density -51.35-36.09 dbw/hz Uplink Calculation Clear Rain Up Rain Dn Units Uplink transmit EIRP 57.13 57.13 57.13 dbw Transponder input back-off (total) 14.00 14.00 14.00 db Input back-off per carrier 26.53 30.37 26.53 db Mispoint loss 0.30 0.30 0.30 db Free space loss 207.15 207.15 207.15 db Atmospheric absorption 0.12 0.12 0.12 db Tropospheric scintillation fading 0.34 0.34 0.34 db Atmospheric losses total 0.46 0.46 0.46 db Total path loss (excluding rain) 207.91 207.91 207.91 db Rain attenuation 0.00 3.84 0.00 db Uplink power control 0.00 0.00 0.00 db Uncompensated rain fade 0.00 3.84 0.00 db C/No (thermal) 79.82 75.99 79.82 db.hz C/N (thermal) 17.77 13.93 17.77 db C/ACI 30.00 26.16 30.00 db C/ASI 35.00 31.16 35.00 db C/XPI 35.00 31.16 35.00 db C/IM 200.00 200.00 200.00 db Eb/(No+Io) 13.30 9.46 13.30 db 10

Downlink Calculation Clear Rain Up Rain Dn Units Satellite EIRP total 47.50 47.50 47.50 dbw Transponder output back-off (total) 9.00 9.00 9.00 db Output back-off per carrier 21.53 25.37 21.53 db Satellite EIRP per carrier 25.97 22.13 25.97 dbw Mispoint loss 0.30 0.30 0.30 db Free space loss 205.03 205.03 205.03 db Atmospheric absorption 0.10 0.10 0.10 db Tropospheric scintillation fading 0.34 0.34 0.34 db Atmospheric losses total 0.45 0.45 0.45 db Total path loss (excluding rain) 205.78 205.78 205.78 db Rain attenuation 0.00 0.00 3.23 db Noise increase due to precipitation 0.00 0.00 3.65 db Downlink degradation (DND) 0.00 0.00 6.88 db Total system noise 105.09 105.09 243.40 K Figure of merit (G/T) 36.53 36.53 32.88 db/k C/No (thermal) 85.32 81.48 78.44 db.hz C/N (thermal) 23.26 19.42 16.38 db C/ACI 40.00 36.16 40.00 db C/ASI 40.00 36.16 40.00 db C/XPI 40.00 36.16 40.00 db C/IM 25.00 21.16 25.00 db Eb/(No+Io) 16.81 12.97 11.71 db Totals per Carrier (End-to-End) Clear Rain Up Rain Dn Units C/No (thermal) 78.74 74.91 76.06 db.hz C/N (thermal) 16.69 12.85 14.01 db C/ACI 29.59 25.75 29.59 db C/ASI 33.81 29.97 33.81 db C/XPI 33.81 29.97 33.81 db C/IM 25.00 21.16 25.00 db C/(No+Io) 77.82 73.98 75.54 db.hz C/(N+I) 15.76 11.93 13.48 db Eb/(No+Io) 11.70 7.86 9.42 db System margin 2.00 2.00 2.00 db Net Eb/(No+Io) 9.70 5.86 7.42 db Required Eb/(No+Io) 5.60 5.60 5.60 db Excess margin 4.10 0.26 1.82 db Earth Station Power Requirements Value Units EIRP per carrier 57.13 dbw Antenna feed flange power per carrier 10.71 dbw Uplink power control 0.00 db HPA output back off 2.00 db Waveguide loss 0.3 db Filter truncation loss 0 db Number of HPA carriers 1 - Total HPA power required 13.0103 dbw Required HPA power capability 20.0000 W Spectral power density -51.35 dbw/hz 11

Space Segment Utilization Value Units Overall link availability 99.940 % Information rate (inc overhead) 4.0920 Mbps Transmit rate 6.4218 Mbps Symbol rate 1.6055 Mbaud Occupied bandwidth 1.6055 MHz Noise bandwidth 62.06 db.hz Minimum allocated bandwidth required 2.0068 MHz Allocated transponder bandwidth 2.0100 MHz Percentage transponder bandwidth used 5.58 % Used transponder power 25.97 dbw Percentage transponder power used 5.58 % Max carriers by transponder bandwidth 17.91 - Max carriers by transponder power 20.85 - Max transponder carriers limited by:- Bandwidth [17.91] 12

Table 3 : STAR Inbound Link Budget - SPOT Contour Digital Link Budget Produced using Satmaster Pro Thursday, August 04, 2005 Service Name AB3 SCPC star Rom Bru 01 16 3/4 Coverage 180cm interf-free,ntc,adj.chan=30db Uplink earth station Roma, Italy Downlink earth station Brussels, Belgium Satellite name AB3 Link Input Parameters Uplink Downlink Units Site latitude 41.90N 50.83N degrees Site longitude 12.48E 4.35E degrees Site altitude 0 0 km Frequency 14.3401 11.0575 GHz Polarization Vertical Horizontal - Rain model ITU (41.4) ITU (28.2) (mm/h or zone) Availability (average year) 99.95 99.99 % Water vapour density 7.5 7.5 gm/m3 Surface temperature 15 15 C Antenna aperture 1.8 8 metres Antenna efficiency / gain 60 55 % (+ prefix dbi) Coupling loss 0.3 0. db Antenna tracking / mispoint error 0.3 0.3 db LNB noise figure / temp - 1 db (+ prefix K) Antenna noise - 30 K Adjacent carrier interference 30 40 db Adjacent satellite interference 35 40 db Cross polarization interference 35 40 db Uplink station HPA output back-off 2 - db Number of carriers / HPA 1 - - HPA C/IM (up) 200 - db Uplink power control 0 - db Uplink filter truncation loss 0 - db Required HPA power capability 8 - W Satellite Input Parameters Value Units Satellite longitude 5.00W degrees Transponder type TWTA - Receive G/T 8 db/k Saturation flux density -83 dbw/m2 Satellite attenuator pad 0 db Satellite ALC 0 db EIRP (saturation) 47.5 dbw Transponder bandwidth 36 MHz Input back off total 14 db Output back off total 9 db Intermodulation interference 25 db Number of transponder carriers AUTO - 13

Carrier/Link Input Parameters Value Units Modulation 16-PSK - Required bit error rate performance 10^-5 - Required Eb/No without FEC coding 17.44 db Required Eb/No with FEC coding 6.0 db Information rate 4 Mbps Overhead 2.3 % FEC code rate 0.7024 - Spreading gain 0 db Reed Solomon code 1 - (1 + Roll off factor) 1.0 - Carrier spacing factor 1.25 - Bandwidth allocation step size 0.01 MHz System margin 2 db Calculations at Saturation Value Units Gain 1m^2 44.59 db/m2 Uplink C/No 109.01 db.hz Downlink C/No 106.85 db.hz Total C/No 104.79 db.hz Uplink EIRP for saturation 80.33 dbw General Calculations Uplink Downlink Units Elevation 38.44 31.13 degrees True azimuth 205.25 191.99 degrees Compass bearing 203.48 192.68 degrees Path distance to satellite 37901.17 38511.47 km Propagation time delay 0.126424 0.128460 seconds Antenna efficiency 60.00 55.00 % Antenna gain 46.42 56.75 dbi Availability (average year) 99.95 99.99 % Link downtime (average year) 4.383 0.877 hours Availability (worst month) 99.790 99.948 % Link downtime (worst month) 1.537 0.379 hours Spectral power density -54.90-36.07 dbw/hz Uplink Calculation Clear Rain Up Rain Dn Units Uplink transmit EIRP 53.16 53.16 53.16 dbw Transponder input back-off (total) 14.00 14.00 14.00 db Input back-off per carrier 26.94 30.77 26.94 db Mispoint loss 0.30 0.30 0.30 db Free space loss 207.15 207.15 207.15 db Atmospheric absorption 0.12 0.12 0.12 db Tropospheric scintillation fading 0.34 0.34 0.34 db Atmospheric losses total 0.46 0.46 0.46 db Total path loss (excluding rain) 207.91 207.91 207.91 db Rain attenuation 0.00 3.84 0.00 db Uplink power control 0.00 0.00 0.00 db Uncompensated rain fade 0.00 3.84 0.00 db C/No (thermal) 81.84 78.01 81.84 db.hz C/N (thermal) 20.21 16.37 20.21 db C/ACI 30.00 26.16 30.00 db C/ASI 35.00 31.16 35.00 db C/XPI 35.00 31.16 35.00 db C/IM 200.00 200.00 200.00 db Eb/(No+Io) 15.04 11.20 15.04 db 14

Downlink Calculation Clear Rain Up Rain Dn Units Satellite EIRP total 47.50 47.50 47.50 dbw Transponder output back-off (total) 9.00 9.00 9.00 db Output back-off per carrier 21.94 25.77 21.94 db Satellite EIRP per carrier 25.56 21.73 25.56 dbw Mispoint loss 0.30 0.30 0.30 db Free space loss 205.03 205.03 205.03 db Atmospheric absorption 0.10 0.10 0.10 db Tropospheric scintillation fading 0.34 0.34 0.34 db Atmospheric losses total 0.45 0.45 0.45 db Total path loss (excluding rain) 205.78 205.78 205.78 db Rain attenuation 0.00 0.00 3.23 db Noise increase due to precipitation 0.00 0.00 3.65 db Downlink degradation (DND) 0.00 0.00 6.88 db Total system noise 105.09 105.09 243.40 K Figure of merit (G/T) 36.53 36.53 32.88 db/k C/No (thermal) 84.91 81.07 78.03 db.hz C/N (thermal) 23.28 19.44 16.40 db C/ACI 40.00 36.16 40.00 db C/ASI 40.00 36.16 40.00 db C/XPI 40.00 36.16 40.00 db C/IM 25.00 21.16 25.00 db Eb/(No+Io) 16.39 12.56 11.30 db Totals per Carrier (End-to-End) Clear Rain Up Rain Dn Units C/No (thermal) 80.10 76.26 76.52 db.hz C/N (thermal) 18.47 14.63 14.89 db C/ACI 29.59 25.75 29.59 db C/ASI 33.81 29.97 33.81 db C/XPI 33.81 29.97 33.81 db C/IM 25.00 21.16 25.00 db C/(No+Io) 78.77 74.94 75.89 db.hz C/(N+I) 17.14 13.30 14.25 db Eb/(No+Io) 12.65 8.82 9.77 db System margin 2.00 2.00 2.00 db Net Eb/(No+Io) 10.65 6.82 7.77 db Required Eb/(No+Io) 6.00 6.00 6.00 db Excess margin 4.65 0.82 1.77 db Earth Station Power Requirements Value Units EIRP per carrier 53.16 dbw Antenna feed flange power per carrier 6.73 dbw Uplink power control 0.00 db HPA output back off 2.00 db Waveguide loss 0.3 db Filter truncation loss 0 db Number of HPA carriers 1 - Total HPA power required 9.0309 dbw Required HPA power capability 8.0000 W Spectral power density -54.90 dbw/hz 15

Space Segment Utilization Value Units Overall link availability 99.940 % Information rate (inc overhead) 4.0920 Mbps Transmit rate 5.8257 Mbps Symbol rate 1.4564 Mbaud Occupied bandwidth 1.4564 MHz Noise bandwidth 61.63 db.hz Minimum allocated bandwidth required 1.8205 MHz Allocated transponder bandwidth 1.8300 MHz Percentage transponder bandwidth used 5.08 % Used transponder power 25.56 dbw Percentage transponder power used 5.08 % Max carriers by transponder bandwidth 19.67 - Max carriers by transponder power 20.75 - Max transponder carriers limited by:- Bandwidth [19.67] 16

Table 4 : STAR Outbound Link Budget - Regional Contour Digital Link Budget Produced using Satmaster Pro Thursday, August 04, 2005 Service Name ABx SCPC star Bru Rom 01 16 2/3 Coverage 180cm interf-free,adj.chan=30db,degr0.5 Uplink earth station Brussels, Belgium Downlink earth station Roma, Italy Satellite name ABx regiona Link Input Parameters Uplink Downlink Units Site latitude 50.83N 41.90N degrees Site longitude 4.35E 12.48E degrees Site altitude 0 0 km Frequency 14.3401 11.0575 GHz Polarization Vertical Horizontal - Rain model ITU (28.2) ITU (41.4) (mm/h or zone) Availability (average year) 99.99 99.95 % Water vapour density 7.5 7.5 gm/m3 Surface temperature 15 15 C Antenna aperture 8 1.8 metres Antenna efficiency / gain 60 55 % (+ prefix dbi) Coupling loss 0.3 0. db Antenna tracking / mispoint error 0.3 0.3 db LNB noise figure / temp - 1 db (+ prefix K) Antenna noise - 30 K Adjacent carrier interference 30 40 db Adjacent satellite interference 35 40 db Cross polarization interference 35 40 db Uplink station HPA output back-off 2 - db Number of carriers / HPA 1 - - HPA C/IM (up) 200 - db Uplink power control 0 - db Uplink filter truncation loss 0 - db Required HPA power capability 200 - W Satellite Input Parameters Value Units Satellite longitude 5.00W degrees Transponder type TWTA - Receive G/T 2 db/k Saturation flux density -80 dbw/m2 Satellite attenuator pad 0 db Satellite ALC 12 db EIRP (saturation) 47.5 dbw Transponder bandwidth 36 MHz Input back off total 3.8 db Output back off total 1.6 db Intermodulation interference 200 db Number of transponder carriers 1-17

Carrier/Link Input Parameters Value Units Modulation 16-PSK - Required bit error rate performance 10^-5 - Required Eb/No without FEC coding 17.44 db Required Eb/No with FEC coding 5.6 db Information rate 74.745 Mbps Overhead 2.3 % FEC code rate 0.6372 - Spreading gain 0 db Reed Solomon code 1 - (1 + Roll off factor) 1.0 - Carrier spacing factor 1.1 - Bandwidth allocation step size 0.01 MHz System margin 2.5 db Calculations at Saturation Value Units Gain 1m^2 44.59 db/m2 Uplink C/No 106.01 db.hz Downlink C/No 94.09 db.hz Total C/No 93.82 db.hz Uplink EIRP for saturation 83.51 dbw General Calculations Uplink Downlink Units Elevation 31.13 38.44 degrees True azimuth 191.99 205.25 degrees Compass bearing 192.68 203.48 degrees Path distance to satellite 38511.47 37901.17 km Propagation time delay 0.128460 0.126424 seconds Antenna efficiency 60.00 55.00 % Antenna gain 59.38 43.79 dbi Availability (average year) 99.99 99.95 % Link downtime (average year) 0.877 4.383 hours Availability (worst month) 99.948 99.790 % Link downtime (worst month) 0.379 1.537 hours Spectral power density -54.45-28.87 dbw/hz Uplink Calculation Clear Rain Up Rain Dn Units Uplink transmit EIRP 79.71 79.71 79.71 dbw Transponder input back-off (total) 3.80 3.80 3.80 db Input back-off per carrier 3.80 9.23 3.80 db Mispoint loss 0.30 0.30 0.30 db Free space loss 207.29 207.29 207.29 db Atmospheric absorption 0.14 0.14 0.14 db Tropospheric scintillation fading 0.36 0.36 0.36 db Atmospheric losses total 0.50 0.50 0.50 db Total path loss (excluding rain) 208.09 208.09 208.09 db Rain attenuation 0.00 5.43 0.00 db Uplink power control 0.00 0.00 0.00 db Uncompensated rain fade 0.00 5.43 0.00 db C/No (thermal) 102.21 96.78 102.21 db.hz C/N (thermal) 27.44 22.01 27.44 db C/ACI 30.00 24.57 30.00 db C/ASI 35.00 29.57 35.00 db C/XPI 35.00 29.57 35.00 db C/IM 200.00 200.00 200.00 db Eb/(No+Io) 20.58 15.14 20.58 db 18

Downlink Calculation Clear Rain Up Rain Dn Units Satellite EIRP total 47.50 47.50 47.50 dbw Transponder output back-off (total) 1.60 1.60 1.60 db Output back-off per carrier 1.60 1.60 1.60 db Satellite EIRP per carrier 45.90 45.90 45.90 dbw Mispoint loss 0.30 0.30 0.30 db Free space loss 204.89 204.89 204.89 db Atmospheric absorption 0.09 0.09 0.09 db Tropospheric scintillation fading 0.30 0.30 0.30 db Atmospheric losses total 0.39 0.39 0.39 db Total path loss (excluding rain) 205.58 205.58 205.58 db Rain attenuation 0.00 0.00 2.19 db Noise increase due to precipitation 0.00 0.00 3.01 db Downlink degradation (DND) 0.00 0.00 5.20 db Total system noise 105.09 105.09 209.94 K Figure of merit (G/T) 23.57 23.57 20.57 db/k C/No (thermal) 92.49 92.49 87.29 db.hz C/N (thermal) 17.72 17.72 12.52 db C/ACI 40.00 40.00 40.00 db C/ASI 40.00 40.00 40.00 db C/XPI 40.00 40.00 40.00 db C/IM 200.00 200.00 200.00 db Eb/(No+Io) 13.58 13.58 8.44 db Totals per Carrier (End-to-End) Clear Rain Up Rain Dn Units C/No (thermal) 92.05 91.12 87.16 db.hz C/N (thermal) 17.28 16.34 12.39 db C/ACI 29.59 24.44 29.59 db C/ASI 33.81 29.19 33.81 db C/XPI 33.81 29.19 33.81 db C/IM 196.99 196.99 196.99 db C/(No+Io) 91.62 90.12 87.01 db.hz C/(N+I) 16.85 15.34 12.24 db Eb/(No+Io) 12.79 11.28 8.18 db System margin 2.50 2.50 2.50 db Net Eb/(No+Io) 10.29 8.78 5.68 db Required Eb/(No+Io) 5.60 5.60 5.60 db Excess margin 4.69 3.18 0.08 db Earth Station Power Requirements Value Units EIRP per carrier 79.71 dbw Antenna feed flange power per carrier 20.33 dbw Uplink power control 0.00 db HPA output back off 2.00 db Waveguide loss 0.3 db Filter truncation loss 0 db Number of HPA carriers 1 - Total HPA power required 22.6259 dbw Required HPA power capability 183.0580 W Spectral power density -54.45 dbw/hz 19

Space Segment Utilization Value Units Overall link availability 99.940 % Information rate (inc overhead) 76.4641 Mbps Transmit rate 120.0002 Mbps Symbol rate 30.0001 Mbaud Occupied bandwidth 30.0001 MHz Noise bandwidth 74.77 db.hz Minimum allocated bandwidth required 33.0001 MHz Allocated transponder bandwidth 33.0100 MHz Percentage transponder bandwidth used 91.69 % Used transponder power 45.90 dbw Percentage transponder power used 100.00 % 20