Metallic macrocell/microcell interface

Claim 1

In a cellular radiotelephone system having a macrocell base station (BS) and a microcell access station responsive to the macrocell BS and providing enhanced service to a sub service area of the service area of the macrocell BS; the system comprising: a digital time division multiplex (TDM) bus having a plurality of time slots shared by both the macrocell BS and the microcell access station in which time slots of the microcell access station are an integral pan of the TDM bus of the macrocell base station; a metallic wire for interconnecting the macrocell BS to the microcell access station; the macrocell BS comprising: a plurality of BS radio channel units (RCUs); at least a first subplurality of the plurality of time slots of the digital time division multiplex (TDM) bus included in the macrocell BS for connecting the BS RCUs to a mobile switching center (MSC); a radio control complex (RCC) located at the BS and connected to and controlling the BS TDM bus; a local TDM bus interface connected to a portion of the BS (TDM) bus included in the macrocell BS and connected to the metallic wire; the microcell access station comprising: a second subplurality of the plurality of time slots of the digital time division multiplex (TDM) bus being located at the microcell access station; a plurality of microcell radio channel units (RCUs) connected to the time slots of the digital time division multiplex (TDM) bus located at the microcell access station; a remote TDM bus interface connected to a portion of the TDM bus located at the microcell access system; the local TDM bus interface and the remote TDM bus interface each including: a link interface with a digital interface for connecting to the metallic wire; a TDM buffer, the TDM buffer of the local TDM bus interface connected to a TDM bus slot of the BS TDM bus included in the macrocell BS and the TDM buffer of the remote TDM bus interface connected to a TDM bus slot of the TDM bus located at the microcell access station; a TDM multi-address control logic circuit connected to the TDM buffer for providing TDM address control; whereby the local and remote TDM bus interfaces are connected together through the metallic wire to incorporate the second plurality of time slots of the digital time division multiplex (TDM) bus as an integral portion of the TDM bus at the macrocell BS.