Low cost fiber optic network node

• US 4,805,234 A
• Filed: 09/30/1986
• Issued: 02/14/1989
• Est. Priority Date: 09/30/1986
• Status: Expired due to Term

• Current Assignee: Mitre Corporation
• Original Assignee: Mitre Corporation
• Inventors: Husbands, Charles R.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Van Beek, Leslie
• Application Number:
  US06/913,682
• Time in Patent Office: 868 Days
• Field of Search: 455/607, 455/601, 455/617, 455/606, 455/600
• US Class Current: 398/58
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks

Abstract

The node includes plural optical receivers and transmitters. Each receiver and each transmitter of the node is connected to a user terminal by fiber optic cables. The output of each of the node receivers is electrically combined. Splitting logic is also included for splitting the electrical output of the receivers to serve as an input to the plural optical transmitters. The node may be used as an expansion mode or as a head-end unit. The optical receivers and transmitters have a low cost so that the overall node is approximately one fifth the cost of comparable nodes utilizing passive optical stars.

Claims

1. Optical node for interconnecting a plurality of user terminals comprising:

a plurality of optical receivers, each receiver connected by fiber optic means to one of the user terminals and producing an electrical output;

electronic means for combining the electrical output of the plurality of receivers;

a plurality of optical transmitters, each transmitter connected by fiber optic means to one of the user terminals;

electronic means for splitting the electrical output of the receivers for driving each of the transmitters,

an additional receiver and transmitter forming expansion port, and

means for selectively connecting said electronic combining means to either (i) said electronic splitting means for operation of said optical node in a head-end mode, or (ii) to the transmitter of said expansion port and connecting said receiver of said expansion port to said electronic splitting means for operation in a repeater mode.

2. Local area optical network comprising:

A. a plurality of user terminals, each terminal including an optical transmitter and an optical receiver; and

B. an optical node connected by fiber optic means to the transmitter and receiver of the plurality of user terminals, the optical node including;

(i) a plurality of optical node receivers, each node receiver connected to the transmitter of one of the user terminals and producing an electrical output;

(ii) electronic means for combining the electrical output of the plurality of node receivers;

(iii) a plurality of optical node transmitters, each node transmitter connected to the receiver of one of the user terminals;

(iv) electronic means for splitting the electrical output of the node receivers for driving each of the node transmitters;

an additional receiver and transmitter forming expansion port, and

means for selectively connecting said electronic combining means to either (i) said electronic splitting means for operation of said optical node in a head-end mode, or (ii) to the transmitter of said expansion port and connecting said receiver of said expansion port to said electronic splitting means for operation in a repeater mode.