This Recommendation describes MAC layer specification of second generation high performance Network over Coax (HiNoC) which provide 1 Gbit/s data transmission over coaxial networks in the cable industry. HiNoC consists of HiNoC Bridge (HB) and HiNoC Modem (HM) in terms of architectural functional entity and is layered as Media Access Control (MAC) layer and Physical (PHY) layer. HiNoC 2.0 selects the Time Division Duplexing (TDD) mode to adjust the bandwidth for upstream and downstream feasibly. HiNoC 2.0 selects Time Division Multiple Access (TDMA) and optional Orthogonal Frequency Division Multiple Access (OFDMA). The HiNoC 2.0 MAC (HiMAC) layer is composed of the Convergence Sublayer (CS), the Common Part Sublayer (CPS) and the Security Sublayer (SS). This document contains descriptions for HiMAC frame types, functions and mechanisms of CS and CPS.