security, etc., and the tolerance against harsh environment in space is one of the most
demanding in terms of dependability as IoT applications.
Space systems are integrated with ground network systems that consist of highperformance computers and high-performance network appliances as shown in
Fig. 2 [9]. The Internet has already been expanded outside of the Earth’s atmosphere.
Figure 3 shows the Ethernet Interface Unit (EIU) developed for the International
Space Station (ISS) [10]. Such equipment for the Internet is installed inside a
structure. On the other hand, sensors used for IoT applications are placed outside
of structures. Harsh environment as cosmic radiations and wide temperature range in
outer space must be taken into consideration. As for semiconductor devices, soft
errors caused by cosmic radiations are major concern, and heat must be dissipated
through limited conduction path.
Satellites are placed and utilized in outer space as shown in Fig. 4 [11], and hence
the limitation of the capacity of transmission channels between satellites and ground
stations must be considered in the system integration. Needless to say, the functionality of the space system must be available at all times even in harsh environment
with high level radiation and wide temperature range. Once a successful launch is
achieved and the spacecraft is stabilized in the orbit after the initial operational
preparation period, it is necessary to consider the external environment such as the
temperature difference and radiation environment peculiar to the space. Electronic
parts used in spacecraft are exposed to vibration levels ranging from 10 to 20 G and
Agriculture
Transportation
Logistics Remote monitoring
Energy
Disaster prevention Wellness
LTE
WiMAX
Ethernet
xDSL, FTTH
3G
Wi-Fi
ZigBee / IrDA / Specified low-power radio / Bluetooth / Z-Wave
Expertise
Knowledge
produced
by society
Fig. 1 IoT using embedded processors. http://www.nec.com/en/global/solutions/nsp/m2m/con
cept/ [1]
36
H. Hihara et al.
demanding in terms of dependability as IoT applications.
Space systems are integrated with ground network systems that consist of highperformance computers and high-performance network appliances as shown in
Fig. 2 [9]. The Internet has already been expanded outside of the Earth’s atmosphere.
Figure 3 shows the Ethernet Interface Unit (EIU) developed for the International
Space Station (ISS) [10]. Such equipment for the Internet is installed inside a
structure. On the other hand, sensors used for IoT applications are placed outside
of structures. Harsh environment as cosmic radiations and wide temperature range in
outer space must be taken into consideration. As for semiconductor devices, soft
errors caused by cosmic radiations are major concern, and heat must be dissipated
through limited conduction path.
Satellites are placed and utilized in outer space as shown in Fig. 4 [11], and hence
the limitation of the capacity of transmission channels between satellites and ground
stations must be considered in the system integration. Needless to say, the functionality of the space system must be available at all times even in harsh environment
with high level radiation and wide temperature range. Once a successful launch is
achieved and the spacecraft is stabilized in the orbit after the initial operational
preparation period, it is necessary to consider the external environment such as the
temperature difference and radiation environment peculiar to the space. Electronic
parts used in spacecraft are exposed to vibration levels ranging from 10 to 20 G and
Agriculture
Transportation
Logistics Remote monitoring
Energy
Disaster prevention Wellness
LTE
WiMAX
Ethernet
xDSL, FTTH
3G
Wi-Fi
ZigBee / IrDA / Specified low-power radio / Bluetooth / Z-Wave
Expertise
Knowledge
produced
by society
Fig. 1 IoT using embedded processors. http://www.nec.com/en/global/solutions/nsp/m2m/con
cept/ [1]
36
H. Hihara et al.