Optical communication system and method for installing it

Abstract

An optical signal communication system employs an optical signal conduit that is threaded through segments of a utility pipe, such as a water main. Water-tight optical signal transfer fittings are used so that the optical signal conduit does not need to run through valves in the water main.

What I claim is:  
     
         1 . A method for installing an optical communication conduit, comprising: 
 boring a first hole through a section of pipe that carries a fluid;    boring a second hole through the section of pipe at a position spaced apart from the first hole;    introducing the optical communication conduit into the section of pipe through one of the holes; and    threading the optical communication conduit through the section of pipe toward the other hole.    
     
     
         2 . The method of  claim 1 , wherein the step of threading the optical communication conduit through the section of pipe comprises the steps of attaching the optical signal conduit to an elongated guide strip, introducing the guide strip into the section of pipe through one of the holes, and moving the guide strip between the holes.  
     
     
         3 . The method of  claim 1 , further comprising the steps of connecting the optical communication conduit to a fluid-tight optical signal transfer fitting, and attaching the fluid-tight optical signal transfer fitting to the section of pipe at the second hole.  
     
     
         4 . The method of  claim 3 , wherein the section of pipe is a section of a pipeline which additionally includes another section of pipe and a valve between the sections of pipe, wherein the second hole is bored adjacent the valve, and further comprising the steps of boring a third hole in the another section of pipe adjacent the valve, threading another portion of the optical signal conduit into the another section of pipe, connecting the another portion of the optical signal conduit to another fluid-tight optical signal transfer fitting, and attaching the another fluid-tight optical signal transfer fitting to the another section of pipe at the third hole.  
     
     
         5 . The method of  claim 4 , further comprising the step of connecting a valve-bypass segment of the optical signal conduit between the fluid-tight optical signal transfer fittings.  
     
     
         6 . The method of  claim 4 , further comprising the step of connecting a local signal distribution unit to the optical signal conduit in the sections of pipe via the fluid-tight optical signal transfer fittings, the local signal distribution unit providing customers with access to the optical communication conduit.  
     
     
         7 . The method of  claim 6 , wherein the local signal distribution unit comprises an optical coupler.  
     
     
         8 . The method of  claim 1 , further comprising the step of introducing, into the section of pipe, means for taking up slack in the optical signal conduit, the means for taking up slack being introduced through one of the holes.  
     
     
         9 . The method of  claim 1 , further comprising the step of attaching a fluid-tight optical signal transfer fitting to the section of pipe at the second hole, the optical communication conduit passing through the second hole via the fluid-tight optical signal transfer fitting.  
     
     
         10 . The method of  claim 1 ,wherein the optical signal conduit threaded through the section of pipe is a single optical fiber.  
     
     
         11 . The method of  claim 1 , wherein the optical fiber is unjacketed, and hence exposed to the fluid.  
     
     
         12 . The method of  claim 1 , wherein the fluid is water and the segment of pipe is a segment of a water main.  
     
     
         13 . An optical signal communication conduit installed in the water main by the method of  claim 12 .  
     
     
         14 . A method for installing an optical communication conduit, comprising: 
 boring a first hole through a section of a water main that carries potable water to customers;    boring a second hole through the section of the water main;    introducing the optical communication conduit into the section of the water main through one of the holes;    attaching a first water-tight optical signal transfer fitting to the section of the water main at the first hole, with the optical signal conduit passing through the first water-tight optical signal transfer fitting; and    attaching a second water-tight optical signal transfer fitting to the section of the water main at the second hole, with the optical signal conduit passing through the second water-tight optical signal transfer fitting.    
     
     
         15 . The method of  claim 14 , wherein the optical signal conduit comprises at least one optical fiber.  
     
     
         16 . The method of  claim 15 , wherein the at least one optical fiber is unjacketed, so that the at least one optical fiber is exposed to the water carried by the water main.  
     
     
         17 . The method of  claim 15 , further comprising the step of connecting the at least one optical fiber to a local signal distribution unit that is disposed outside the water main.  
     
     
         18 . The method of  claim 14 , wherein the water main also has another section, and a valve between the sections of the water main, wherein the second hole is bored adjacent the valve adjacent the valve, and further comprising the steps of boring a third hole in the another section of the water main, threading another portion of the optical signal conduit into the another section of the water main, and attaching a third water-tight optical signal transfer fitting to the another section of the water main at the third hole.  
     
     
         19 . An optical communication conduit installed in a water main by the method of  claim 18 , wherein the second and third water-tight optical signal transfer fittings are linked outside the water main by means for transferring optical signals.  
     
     
         20 . An optical communication conduit installed in a water main by the method of claim  14 .