Wave division multiplexer arrangement for small cell networks

Patent metadata

Field	Value
Publication number	US-9438513-B2
Application number	US-201414468913-A
Country	US
Kind code	B2
Filing date	Aug 26, 2014
Priority date	Aug 26, 2013
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A passive optical network includes a central office providing subscriber signals; a fiber distribution hub including an optical power splitter and a termination field; and a drop terminal. Distribution fibers have first ends coupled to output ports of a drop terminal and second ends coupled to the termination field. A remote unit of a DAS is retrofitted to the network by routing a second feeder cable from a base station to the hub and coupling one the distribution fibers to the second feeder cable. The remote unit is plugged into the corresponding drop terminal port, for example, with a cable arrangement having a sealed wave division multiplexer.

First claim

What is claimed is:

1. A method of retrofitting a remote unit of a Distributed Antenna System to an existing passive optical network including end subscribers coupled to a central office via at least a fiber distribution hub and a drop terminal, the method comprising:
providing a distribution cable including a plurality of distribution fibers, each distribution fiber having a first end plugged into a termination field at the fiber distribution hub and a second end coupled to a first output port of the drop terminal, at least some of the distribution fibers being coupled to the central office via a first feeder cable;
optically coupling at the termination field a first end of a first of the distribution fibers to a second feeder cable that carries optical signals from a base station so that the optical signals from the base station are carried to the first output port of the drop terminal while another output port of the drop terminal remains connected to one of the end subscribers; and
optically coupling the remote unit to the first output port of the drop terminal so that the remote unit receives the optical signals carried to the first output port by the second feeder cable, wherein optically coupling the remote unit to the first output port of the drop terminal includes:
plugging a connectorized first end of a cable arrangement into the first output port of the drop terminal; and
plugging connectorized second ends of the cable arrangement into ports at the remote unit,
the cable arrangement including a first optical fiber, a plurality of second optical fibers, a wave division multiplexer coupled to the first optical fiber and second optical fibers, and a sealed enclosure surrounding at least the wave division multiplexer to protect against a surrounding environment, the wave division multiplexer being configured to multiplex and demultiplex optical signals carried between the first optical fiber and the second optical fibers based on wavelengths of the optical signals.

2. The method of claim 1 , wherein plugging the connectorized second ends of the cable arrangement into the ports at the remote unit comprises plugging pairs of the connectorized second ends into pairs of transmit and receive ports at the remote unit.

3. A method of retrofitting a remote unit of a Distributed Antenna System to an existing passive optical network including end subscribers coupled to a central office via at least a fiber distribution hub and a drop terminal, the method comprising:
providing a distribution cable including a plurality of distribution fibers, each distribution fiber having a first end plugged into a termination field at the fiber distribution hub and a second end coupled to a first output port of the drop terminal, at least some of the distribution fibers being coupled to the central office via a first feeder cable;
optically coupling at the termination field a first end of a first of the distribution fibers to a second feeder cable that carries optical signals from a base station so that the optical signals from the base station are carried to the first output port of the drop terminal while another output port of the drop terminal remains connected to one of the end subscribers; and
optically coupling the remote unit to the first output port of the drop terminal so that the remote unit receives the optical signals carried to the first output port by the second feeder cable; wherein optically coupling the first end of the first distribution fiber to the second feeder cable comprises:
plugging one end of the second feeder cable into a port at a first side of the termination field;
uncoupling the first end of the first distribution fiber from a splitter pigtail at the termination field; and
plugging the first end of the first distribution fiber into a port at a second side of the termination field, the port at the second side connecting to the port at the first side.

4. A passive optical network comprising:
a first signal source providing first optical signals;
a second signal source providing second optical signals;
a fiber distribution hub including an optical power splitter and a termination field, the optical power splitter being configured to split the first optical signals carried by a first feeder cable from the first signal source to a plurality of splitter pigtails that are plugged into the termination field, the termination field also receiving a connectorized end of a second feeder cable that carries the second optical signals from the second signal source;
a drop terminal coupled to the fiber distribution hub by a distribution cable that carries the first optical signals and the second optical signals, the drop terminal having a first port receiving the first optical signals and a second port receiving the second optical signals;
a remote unit coupled to the second port of the drop terminal, the remote unit including an antenna for broadcasting the second optical signals received at the remote unit; and
a cable arrangement having a first end and a plurality of second ends, the first end being plugged into the second port at the drop terminal, the second ends being plugged into ports of the remote unit, thereby coupling the remote unit to the second port of the drop terminal, the cable arrangement including a wave division multiplexer that multiplexes and demultiplexes the second optical signals received at the first and second ends of the cable arrangement.

5. The passive optical network of claim 4 , wherein the distribution cable includes multiple distribution fibers, each distribution fiber having a first end coupled to an output port of the drop terminal and a second end coupled to the termination field, wherein the second end of at least a first of the distribution fibers is optically coupled to a splitter pigtail at the termination field, and wherein the second end of at least a second of the distribution fibers is optically coupled to the second feeder cable.

6. The passive optical network of claim 4 , further comprising a drop cable routed between the drop terminal and an end subscriber, the drop cable being optically coupled at the first port of the drop terminal to receive the first optical signals.

7. The cable arrangement of claim 4 , wherein the cable arrangement comprises:
a first optical fiber that defines the first end;
a plurality of second optical fibers that define the plurality of second ends;
a wave division multiplexer coupled to the first optical fiber and second optical fibers, the wave division multiplexer being configured to multiplex and demultiplex optical signals carried between the first optical fiber and the second optical fibers based on wavelengths of the optical signals; and
a sealed enclosure surrounding at least the wave division multiplexer to protect against a surrounding environment.

8. The cable arrangement of claim 7 , wherein the sealed enclosure surrounds at least a portion of the first optical fiber and at least portions of the second optical fibers.

9. The cable arrangement of claim 7 , wherein distal ends of the first and second optical fibers are terminated by hardened optical connectors.

10. The cable arrangement of claim 7 , wherein the plurality of second optical fibers includes between two and thirty-two optical fibers.

11. The cable arrangement of claim 10 , wherein the plurality of second optical fibers includes sixteen optical fibers.

12. The passive optical network of claim 4 , wherein at least a portion of the cable arrangement is sealed from a surrounding environment.

13. The passive optical network of claim 4 , wherein the first end of the cable arrangement is terminated by a h

Assignees

• Adc Telecommunications Inc
• Commscope Technologies Llc

Inventors

• Gronvall Erik
• Smith Trevor D
• Badar Timothy G
• Lefebvre Anthony L

Classifications

• G02B6/4248

  Feed-through connections for the hermetical passage of fibres through a package wall (see provisionally also G02B6/4428) · CPC title

• G02B6/44465

  Seals · CPC title

• G02B6/44265

  Fibre-to-antenna cables; Auxiliary devices thereof · CPC title

• G02B6/44528

  Patch-cords; Connector arrangements in the system or in the box (routing arrangements H04Q1/00) · CPC title

• H04B10/25754 Primary

  Star network topology · CPC title