Multicast transmission with energy-proportional power-gating scheme for wireless interconnects NoC

To reduce the energy consumption as well as the thermal problem of wireless routers (WRs) in a wireless network-on-chip (WiNoC) for high performance computing (HPC) is a critical problem for energy efficiency since WRs consume a lot of energy and generate a lot of heat. Using multicast transmission is one of the techniques to achieve HPC in a full-connected WiNoC (full-WiNoC) architecture (i.e., one-time transmission to multiple receivers). This paper presents a problem that in multicast transmission non-multicast members (i.e., WRs) do not switch off their power in full-WiNoC and waste their energy. To solve this problem, we propose a power-gating (PG) technique for WRs to transmit multicast, called energy-proportional multicast scheme (EMS), in full-WiNoC for energy efficiency. EMS can achieve a lower energy consumption based on temporally switching off those non-multicast WRs by using PG technique during multicast transmissions. It shows that an EMS-designed full-WiNoC for multicast can reduce 91% energy consumption at most as compared with the wired interconnects NoC in a 16 WRs case. It also shows that full-WiNoC with EMS can reduce 65% energy consumption than full-WiNoC without EMS. This investigation encourages the design of EMS in full-WiNoC for HPC on energy efficiency.