Scalability of Broadcast Performance in Wireless Network-on-Chip

• Published in: IEEE transactions on parallel and distributed systems 2016-12, Vol.27 (12), p.3631-3645
• Main Authors: Abadal, Sergi, Mestres, Albert, Nemirovsky, Mario, Heekwan Lee, Gonzalez, Antonio, Alarcon, Eduard, Cabellos-Aparicio, Albert
• Format: Article
• Language: English
• Subjects: Access protocols; Arquitectura de computadors; Arquitectures paral·leles; Broadband; broadcast; Channel capacity; Chips; Communications traffic; Computer architecture; Comunicació sense fil, Sistemes de; design space exploration; Enginyeria de la telecomunicació; hybrid NoC; Informàtica; Interconnections; latency; MAC protocols; manycore processors; multicast; Multicasting; Multiprocessing; Multiprocessor interconnection networks; Network-on-chip; Parallel architectures; Parallel processing (Electronic computers); Processament en paral·lel (Ordinadors); Program processors; Scalability; System-on-chip; Telemàtica i xarxes d'ordinadors; Throughput; Wireless communication; Wireless communication systems; Wireless networks; wireless on-chip communication; Àrees temàtiques de la UPC
• ISSN: 1045-9219; 1558-2183
• DOI: 10.1109/TPDS.2016.2537332

Networks-on-Chip (NoCs) are currently the paradigm of choice to interconnect the cores of a chip multiprocessor. However, conventional NoCs may not suffice to fulfill the on-chip communication requirements of processors with hundreds or thousands of cores. The main reason is that the performance of such networks drops as the number of cores grows, especially in the presence of multicast and broadcast traffic. This not only limits the scalability of current multiprocessor architectures, but also sets a performance wall that prevents the development of architectures that generate moderate-to-high levels of multicast. In this paper, a Wireless Network-on-Chip (WNoC) where all cores share a single broadband channel is presented. Such design is conceived to provide low latency and ordered delivery for multicast/broadcast traffic, in an attempt to complement a wireline NoC that will transport the rest of communication flows. To assess the feasibility of this approach, the network performance of WNoC is analyzed as a function of the system size and the channel capacity, and then compared to that of wireline NoCs with embedded multicast support. Based on this evaluation, preliminary results on the potential performance of the proposed hybrid scheme are provided, together with guidelines for the design of MAC protocols for WNoC.