ARISS workshop UoS Wolf-Henning Rech DF9IC1 DATV on ISS ? How can this become a reality? Wolf-Henning Rech DF9IC / N1EOW Thomas Sailer HB9JNX / AE4WA

ARISS workshop UoS Wolf-Henning Rech DF9IC2 D-ATV on ISS? zUse open worldwide commercial broadcast standards - this ensures easy availability of receiving equipment zDVB / ETSI standards: yDVB-S (EN ) since 1994 yDVB-S2 (EN ) since 03/2005 zDVB-S FTA receiver costs EUR (Germany, 2005)

ARISS workshop UoS Wolf-Henning Rech DF9IC3 D-ATV on ISS? zDigital vs. analogue (FM) ATV: yscalable performance / bandwidth / RX sensitivity ymultiple video and audio streams available y dB better link performance yPA needs better linearity / has less efficiency ysource encoder causes latency yhard degradation in presence of strong interference

ARISS workshop UoS Wolf-Henning Rech DF9IC4 D-ATV on ISS? zBlock diagramm of a DTV transmitter... : z.... and a receiver: A/D converter Source Encoder Channel Encoder RF mo- dulator Video camera Video monitor Digital TV set-top box Upcon- verter D/A converter Source Decoder Channel Decoder RF demo- dulator Down- converter

ARISS workshop UoS Wolf-Henning Rech DF9IC5 D-ATV on ISS? zSource Encoder: yremoves redundant and irrelevant parts of the signal ytrade-off between data rate and signal quality/latency y Mbit/s low quality Mbit/s high quality for SDTV A/D converter Source Encoder Analog 5 MHz BW Digital Mbit/s Digital Mbit/s

ARISS workshop UoS Wolf-Henning Rech DF9IC6 D-ATV on ISS? zChannel Encoder: yadds redundancy to the source coded signal for error correction capability yR = input data rate / output data rate = 7/8... 1/4 ytrade-off between required E b /N 0 at receiver and bandwidth Source Encoder Digital Mbit/s Channel Encoder Digital 120 Mbit/s Digital 1.5 Mbit/s

ARISS workshop UoS Wolf-Henning Rech DF9IC7 D-ATV on ISS? zSource encoding: yMPEG-2 (DVB-S and DVB-S2) yMPEG-4 / H.264 (DVB-S2) for HDTV zChannel encoding and modulation yQPSK with R = 1/2 FEC with convolutional + Reed- Solomon coding (DVB-S) yQPSK with R = 1/2 - 1/4 FEC with BCH + LDPC coding (DVB-S2)

ARISS workshop UoS Wolf-Henning Rech DF9IC8 D-ATV on ISS? Source: ETSI TR

ARISS workshop UoS Wolf-Henning Rech DF9IC9 D-ATV on ISS? zRequired E b /N 0 incl. implementation loss: y5 dB for DVB-S and 2 dB for DVB-S2 ycompare to >20 dB for 1200 Baud AFSK => times better efficiency zReceiver noise level (N 0 ): yT = 290 K => N 0 = -174 dBm/Hz yRequired signal power for 2 Mbit/s is -106 dBm for DVB-S and -109 dBm for DVB-S2 ycompare to -120 dBm for FM voice signal at threshold and -115 dBm for 9600 Bd packet radio

ARISS workshop UoS Wolf-Henning Rech DF9IC10 D-ATV on ISS? z„Quick and dirty“ link analysis (1): yassumed that the patch antenna at ISS is useable up to +-70° with 0 dB i gain (hopefully!) ythen the minimum elevation at ground station is 10° and the maximum path length is around 1200 km 1200 km 300 km ISS Ground station 70° 10° SSETI Express Patch Antenna

ARISS workshop UoS Wolf-Henning Rech DF9IC11 D-ATV on ISS? z„Quick and dirty“ link analysis (2): y GHz mean 162 dB path loss yTX EIRP assumed +40 dBm (+10 dBW, 10 W at the antenna feeding point with 0 dB i gain) yRX antenna assumed 1 m diameter dish with 40 % efficiency, 10° angle at -3 dB and 24 dB i gain yresults in a received signal power of ( ) dBm = -98 dBm y8 dB margin at -106 dBm RX sensitivity

ARISS workshop UoS Wolf-Henning Rech DF9IC12 D-ATV on ISS? zAmateur radio hardware for DVB-S: MPEG Encoder DVB-S receiver Main unit with baseband processor 2400 MHz modulator Power Amplifier (DB6NT) 2.4 GHz1.2 GHz Video camera

ARISS workshop UoS Wolf-Henning Rech DF9IC13 D-ATV on ISS? z... and what comes out of it

ARISS workshop UoS Wolf-Henning Rech DF9IC14 D-ATV on ISS? zSummary: yDigital video over 1200 km LOS path is possible with a 10 W EIRP transmitter and 24 dB i receiver antenna gain yLow cost transmitter technology is available to amateur radio and can be modified / adapted to the special needs at ISS yGround station is more complex that for FM voice operation but within the capabilities of technically skilled hams

ARISS workshop UoS Wolf-Henning Rech DF9IC15 D-ATV on ISS? zWhen and how does it happen?