For example, take SGBs A, B, and C, with SGB A being the HSGB. SGB A is chosen to be the HSGB because it has more battery life than bins B and C and, as the least used bin, is expected to consume less energy.
Therefore, based on time d calculated by the router, one of the SGBs, A, B, or C, becomes the HSGB. Figure 6 shows a flowchart of an energy-efficient cooperation-based operation of a SGB.
Furthermore, when a communication problem occurs in a HSGB, the header authority is delegated to another SGB for communication reliability.
At this time, if the capacity of the SGB exceeds 90% or if the battery life drops below 5%, the SGB sends its status information to the HSGB and enters sleep mode.
The communication problem is then reported to the server through the HSGB. However, in the case of a communication problem in the HSGB, the header authority should be delegated to another SGB.
For group B, which also had ten SGBs, a HSGB was delegated by the router and was changed to another bin depending on the battery status of all SGBs in the area.