A base station system includes a central hub having a baseband controller and a backhaul connection to an external network and a plurality of remote units that are connected to the central hub by respective wired power and cabling connections, each remote unit including an associated drone unit that has an aerial drone and a radio unit mounted thereon. The radio units are operated under control of the baseband controller to form a super cell that appears as a single base station to the external network

The second communication device is in one level higher in a logical network forming a tree structure and sends data to the first communication device. The third communication device is in two or more levels higher in the logical network. The third device is configured to send data to the first communication device without passing through the second communication device. The first communication devices comprises a monitoring unit and a connection switching unit. The monitoring unit is configured to monitor an operation state of the second communication device. The connection switching unit is configured to send a request for sending data to the third communication device, in a case that the normal operation state of the second communication device is not confirmed by the monitoring unit.

The second communication device is in one level higher in a logical network forming a tree structure and sends data to the first communication device. The third communication device is in two or more levels higher in the logical network. The third device is configured to send data to the first communication device without passing through the second communication device. The first communication devices comprises a monitoring unit and a connection switching unit. The monitoring unit is configured to monitor an operation state of the second communication device. The connection switching unit is configured to send a request for sending data to the third communication device, in a case that the normal operation state of the second communication device is not confirmed by the monitoring unit.

Methods, systems, and devices for data management are described. A datacenter may include one or more servers and an offline key storage system. The datacenter may receive, via a server and from a multi-party computation (MPC) coordinator, a first request to access a key share associated with an MPC node. The server may transmit a second request for the key share associated with the MPC node via a first cross domain communication path to an offline key storage system. The offline key storage system may verify a digital signature included with the second request. The offline key storage system may transmit a response including the key share that is encrypted using an encryption key associated with the MPC node to the server via a second cross domain communication path. The server may transmit a communication including the encrypted key share to the MPC coordinator.

Methods, systems, and devices for data management are described. A datacenter may include one or more servers and an offline key storage system. The datacenter may receive, via a server and from a multi-party computation (MPC) coordinator, a first request to access a key share associated with an MPC node. The server may transmit a second request for the key share associated with the MPC node via a first cross domain communication path to an offline key storage system. The offline key storage system may verify a digital signature included with the second request. The offline key storage system may transmit a response including the key share that is encrypted using an encryption key associated with the MPC node to the server via a second cross domain communication path. The server may transmit a communication including the encrypted key share to the MPC coordinator.