Network coding method and apparatus for reliable communication in LoRa communication system

1. A network coding apparatus, comprising:

a network server connected to an end node over a network to receive a packet transmitted by the end node in a long-range sub-GHz module (“LoRa”) communication system;

a stationary gateway positioned between the network server and the end node to deliver the packet, transmitted by the end node, to the network server;

a temporary gateway positioned between the stationary gateway and the end node to deliver the packet, transmitted by the end node, to the stationary gateway; and

wherein when the temporary gateway is an active state, the temporary gateway wiretaps a packet transmission of the end node or a different temporary gateway, stores the packet transmission in a packet, and delivers the packet in response to a request from the network server.

2. The network coding apparatus of claim 1 , wherein when the temporary gateway is an active state, the temporary gateway receives a packet of the end node or a different temporary gateway, forms a single new packet by linearly combining the received packets, and switches to an inactive state when a maximum activation time elapses.

3. The network coding apparatus of claim 1 , wherein the end node transmits the packet using the temporary gateway as a delivery target when the end node recognizes that ACK is not received from the stationary gateway.

4. A network coding apparatus, comprising:

a network server connected to an end node over a network to receive a packet transmitted by the end node in a long-range sub-GHz module (“LoRa”) communication system;

a stationary gateway positioned between the network server and the end node to deliver the packet, transmitted by the end node, to the network server; and

a temporary gateway positioned between the stationary gateway and the end node to deliver the packet, transmitted by the end node, to the stationary gateway, wherein the temporary gateway has a low operation period in which an active state and an inactive state are repeated and has a relatively higher operation period than the end node.

5. A network coding method, comprising:

being connected, by a temporary gateway, to an end node over a network and receiving a packet transmitted by the end node in a long-range sub-GHz module (“LoRa”) communication system;

delivering, by the temporary gateway, the packet transmitted by the end node to a stationary gateway in order to deliver the packet transmitted by the end node to a network server through the stationary gateway; and

wherein the temporary gateway has a low operation period in which the active state and the inactive state are repeated and has a relatively higher operation period than the end node.

6. The network coding method of claim 5 , wherein being connected, by a temporary gateway, to an end node over a network and receiving a packet transmitted by the end node comprises:

being set, by the temporary gateway, as an active state;

receiving the packet transmitted by the end node in the active state;

determining whether the received packet is normal;

forming a single new packet by linearly combining the received packets;

checking whether a time of the active state has exceeded a preset maximum activation time;

switching to an inactive state when the maximum activation time elapses; and

checking whether a time of the inactive state has exceeded a preset maximum deactivation time.

7. The network coding method of claim 5 , wherein delivering, by the temporary gateway, the packet transmitted by the end node to a stationary gateway comprises:

being set, by the temporary gateway, as an active state at an appointed time previously agreed with the network server;

receiving, by the temporary gateway, a sequence of a packet that has not been received from the network server;

identifying, by the temporary gateway, whether the sequence of the packet is present in a list of packets owned by the temporary gateway;

transmitting, by the temporary gateway, the packet to the stationary gateway if the sequence of the packet is present in the list;

deleting, by the temporary gateway, the packet; and

switching, by the temporary gateway, to an inactive state.

8. The network coding method of claim 5 , further comprising delivering, by the stationary gateway, the packet transmitted by the end node to the network server in response to a request from the network server.