Multi-port accumulator for radio-over-fiber (RoF) wireless picocellular systems

Abstract

A multi-port accumulator apparatus for a radio-over-fiber (RoF) wireless picocellular system that includes a housing that supports a tail cable port and a number of RoF transponder ports. The tail cable port is optically coupled to the RoF transponder ports so as to provide for optical transmission of uplink and downlink optical signals between the tail cable port and each of the transponder ports. The tail cable port is also electrically coupled to each transponder port so as to provide electrical power to each of the plurality of transponder ports. The multi-port accumulator supports two or more RoF transponders, one at each RoF transponder port. Each RoF transponder includes a directional antenna system that forms a picocellular coverage sub-area, with the combined sub-areas constituting a picocellular coverage area for the multi-port accumulator. The multi-port accumulator allows for the quick installation and deployment of large numbers of RoF transponders without having to individually connect each RoF transponder to a pair of downlink and uplink optical fibers carried by an optical fiber RF communication link.

1 . A multi-port accumulator apparatus for operably supporting two or more radio-over-fiber (RoF) transponders and for providing a connection to a tail cable that carries uplink and downlink optical signals and electrical power, comprising:
 a housing;   two or more RoF transponder ports supported by the housing, with each RoF transponder port configured to operably connect to one of the RoF transponders;   a tail cable port supported by the housing and configured to operably connect to the tail cable, the tail cable port being optically and electrically connected to each RoF transponder port so as to provide the uplink and downlink optical signals and the electrical power to each RoF transponder.   
   
   
       2 . The apparatus of  claim 1 , wherein:
 the tail cable port is adapted to receive two or more external pairs of uplink and downlink optical fibers carried by the tail cable;   the tail cable port is optically coupled to the two or more RoF transponder ports via respective two or more internal pairs of uplink and downlink optical fiber sections; and   the tail cable port is configured to optically couple the external pairs of uplink and downlink optical fibers to the internal pairs of uplink and downlink optical fibers.   
   
   
       3 . The apparatus of  claim 2 , wherein:
 the tail cable port is adapted to receive an external electrical power line carried by the tail cable and that carries the electrical power;   the tail cable port is electrically coupled to the two or more RoF transponder ports via respective two or more internal electrical power line sections; and   the tail cable port is configured to electrically couple the external electrical power line to the two or more internal electrical power line sections so as to provide electrical power to each of the RoF transponders.   
   
   
       4 . The apparatus of  claim 1 , wherein the housing has four sidewalls and four RoF transponder ports, with one transponder port supported by each sidewall. 
   
   
       5 . The apparatus of  claim 1 , wherein the apparatus has associated therewith a picocell coverage area made up of two or more picocell coverage sub-areas respectively formed by the two or more RoF transponders. 
   
   
       6 . The apparatus of  claim 1 , wherein at least one of the RoF transponders includes an antenna system having an adjustable antenna directivity. 
   
   
       7 . The apparatus of  claim 1 , wherein at least one of the RoF transponders includes a patch antenna. 
   
   
       8 . An RoF wireless picocellular system, comprising:
 two or more multi-port accumulator apparatuses according to  claim 1 , with each multi-port accumulator apparatus optically coupled to a corresponding one of the tail cables.   
   
   
       9 . The RoF wireless picocellular system of  claim 8 , further including:
 a head-end unit configured to generate downlink optical signals and to receive uplink optical signals; and   a distribution unit optically coupled to the head-end unit and each tail cable so as to distribute the uplink and downlink optical signals between the transponders of each multi-port accumulator apparatus and the head-end unit.   
   
   
       10 . A method of forming a radio-over-fiber (RoF) wireless picocellular coverage area, comprising:
 operably supporting two or more RoF transponders on a housing;   providing downlink optical signals for the two or more RoF transponders to a tail cable port on the housing via a tail cable; and   distributing the downlink optical signals through the housing to one or more of the RoF transponders so that the one or more RoF transponders contribute to forming a picocellular coverage area.   
   
   
       11 . The method of  claim 10 , wherein each RoF transponder receives the downlink optical signals and forms a picocellular coverage sub-area that constitutes a portion of the picocellular coverage area. 
   
   
       12 . The method of  claim 10 , further including:
 operably supporting the two or more RoF transponders at RoF transponder ports that are optically and electrically coupled to the tail cable port.   
   
   
       13 . The method of  claim 12 , further including:
 carrying electrical power in the tail cable in an electrical power line; and   distributing electrical power through the housing via electrical power line sections connected to the tail cable port and each of the RoF transponder ports so as to power each of the RoF transponders.   
   
   
       14 . The method of  claim 10 , wherein each RoF transponder includes an antenna system, and further including adjusting the directivity of at least one of the antenna systems to adjust the corresponding RoF transponder's contribution to the picocellular coverage area. 
   
   
       15 . A multi-port accumulator apparatus for supporting a plurality of RoF transponders for a radio-over-fiber (RoF) wireless picocellular system, comprising:
 a housing;   a plurality of RoF transponder ports supported by the housing, with each RoF transponder port adapted to operably connect with one of the RoF transponders;   a tail cable optically coupled within the housing to the plurality of RoF transponder ports so as to provide for optical transmission of uplink and downlink optical signals between the tail cable and the plurality of RoF transponder ports; and   wherein the tail cable is electrically coupled within the housing to the plurality of RoF transponder ports so as to provide electrical power to each of the plurality of RoF transponder ports.   
   
   
       16 . The apparatus of  claim 15 , further including one RoF transponder operably connected to each RoF transponder port. 
   
   
       17 . The apparatus of  claim 16 , wherein each RoF transponder has a directional antenna system configured to form an associated picocellular coverage sub-area that makes up a picocellular coverage area formed by two or more of the RoF transponders. 
   
   
       18 . The apparatus of  claim 15 , further including:
 a tail cable port supported by the housing and optically and electrically coupled to each RoF transponder port;   a tail cable plug operably fixed to the tail cable at a tail cable end; and   wherein the tail cable is operably connected to the tail cable port via the tail cable plug.   
   
   
       19 . An RoF wireless picocellular system, comprising two or more of the apparatuses of  claim 18 . 
   
   
       20 . The apparatus of  claim 18 , wherein each RoF transponder port is optically coupled to the tail cable port via downlink and uplink optical fiber sections internal to the housing.