The "Field Communication System" for the Japan Ground Self-Defense Force maintains communication even under harsh conditions
- MitaSo up until now hardware radios have been used?
- ARight. So we thought we'd put the software radio technology we'd been researching to good use. The communication devices we are presenting here were developed as software-based radios to enable them to be tailored to a range of purposes. This means that future integration of communications and technological advances can be supported by updating the software. We were also able to reduce costs and make the devices smaller.
- MitaYou mean that using software radios has made greater flexibility possible, while also reducing costs and size?
- ABroadly speaking, that's correct. Next, I'd like to cover the access nodes. Devices such as radios are connected to access nodes that serve as mobile base stations, and multiple access nodes are connected to build networks over a wide range in disaster areas. This enables devices to coordinate with each system type and information terminal, allowing a variety of data to be shared. Satellite connections are also used to maintain communications, allowing the Ground Self-Defense Force to perform their duties smoothly even when private-sector communications infrastructure is out of action.
- MitaIt's a vehicle! When you were talking about base stations, I imagined some kind of small facility, but I guess using a vehicle makes them mobile to enable communication anywhere.
- AWhen a disaster such as a large earthquake occurs, Self-Defense Forces are dispatched from all over Japan, and managed in an organized fashion to provide maximum aid to the disaster area. To achieve this, networks are deployed at each base of activity, enabling troops to stay in contact immediately after a disaster. Access nodes are used to construct these networks. Access nodes can also be carried by Air Self-Defense Force transport planes or large helicopters. The extension of antennas is automated, allowing nodes to be up and running in a short period of time.
- MitaThe vehicle looks very sturdy. The antenna at the back extends up, but it is apparently designed to extend within a small radius, so it doesn't get caught on surrounding trees or buildings.
- MitaThank you for showing us a range of devices people normally don't get a chance to see. I think I have a better idea of the situations they are used in now as well. Can you tell us about the technologies that are put to use in these devices, as well as the communication network?
- ACertainly. Let me go over the NEC technologies that are used in these cases. First, there's the software radio technology that I've already discussed. Installing software enables you to communicate with a range of radios. For example, by switching to the local government disaster prevention radio mode, direct contact can be made between the Self-Defense Forces and local government in the affected area. Communications software can also be added to enable intercommunication with the Marine Self-Defense Force and Air Self-Defense Force, supporting communication in a variety of locations.
- MitaI see. So this can even be used to make contact with local government in disaster areas.
- AWe were also able to make the wideband multi-purpose radio for vehicles I mentioned earlier more compact using software radio technology. In the past it was installed in place of seating in some cases, but making it compact has created more usable space within the vehicle. The terminal is also installed in front of the passenger seat, allowing all services to be used.
- MitaThat's interesting. So the space that the equipment used to take up can now accommodate another person.
- AThe second technology is autonomous distributed networks, which are also known as "ad hoc networks."
- MitaThose are some tricky terms...
- AThis technology allows networks to be constructed between devices automatically, even in emergencies where communication infrastructure can no longer be used. Being able to create networks between devices is extremely important in disaster areas and other emergency situations. For example, imagine that two troop units are moving independently. What would happen if there was an obstacle such as a mountain between these troops and their line of communication was cut off?
- MitaLosing contact in an emergency is something we can't afford to let happen.
- AThat's right. An autonomous distributed network is technology that enables communication to continue even if it is cut off by an obstacle. Other terminals automatically relay data to repair the network.
- AAnother feature is support for high speeds. More specifically, in addition to voice data it can also handle the transfer of data that provides a range of services, as well as multimedia such as video that you have shot. When moving at speed, such as in a helicopter, communication routes normally change, but this is an extremely advanced network that also supports high-speed switching.
- MitaI see... It's a whole different situation compared to how we use smartphones around town.
- AThe next feature is network QoS technology. The network everyone usually uses (Internet communication) is a best-effort service with no guarantees for latency or bandwidth (the amount of data that can be exchanged). However, this is not acceptable for defense-related communication in an emergency. Put simply, this involves technology that automatically locates and uses routes that can guarantee communication. It also incorporates technology for reliably transferring information with higher priority even when a variety of data is mixed together. Technologies such as these are used to guarantee communication latency and communication capacity.
(QoS: Quality of Service)
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