Obviousness

The following analysis identifies potential obviousness combinations for US patent 7706641 under 35 U.S.C. § 103, considering the provided prior art. A person having ordinary skill in the art (POSA) in this field would typically have at least a Bachelor of Science degree in electrical engineering, mechanical engineering, or materials science, coupled with experience in designing and applying fiber optic cabling, optical communication components, and data transmission. They would also possess ordinary creativity and the ability to combine teachings from multiple patents.

Combination 1: US5026141A (G2 Systems) in view of US5134386A (Arbus Inc.)

• G2 Systems (US5026141A): This patent describes a structural monitoring system using fiber optics. While not explicitly an intrusion detection system, it teaches the use of fiber optics for monitoring physical changes.

• Arbus Inc. (US5134386A): This patent describes an intruder detection system and method. It focuses on detecting intruders using various means, though it doesn't specifically detail fiber optic implementation in the claims.

• Motivation for Combination: A POSA, faced with the problem of detecting intrusion in a structure, would be motivated to combine the general concept of intrusion detection (Arbus Inc.) with the physical monitoring capabilities of fiber optics (G2 Systems). Fiber optic sensors are known for detecting minute disturbances, offering long-range capabilities, and resisting electromagnetic interference, making them ideal for security applications. The use of fiber optics for structural monitoring inherently involves detecting movement or changes in the fiber's characteristics, which a POSA would recognize as applicable to intrusion detection.

• Obviousness Argument for Claim 1:

  • Providing optical fiber cable, source, and sensor arrangement: Both G2 Systems and Arbus Inc. (by implication of an "intruder detection system") teach the need for a sensing medium and associated electronics. The use of optical fiber cables, light sources, and sensor arrangements is fundamental to fiber optic sensing.
  • Injecting light and detecting signals: G2 Systems explicitly teaches injecting light into fibers and detecting transmitted light for monitoring.
  • Comparing and analyzing changes to detect manipulation/movement and generate alarm: The core function of G2 Systems is to monitor for changes, which can be analyzed to indicate manipulation. Arbus Inc. describes generating an alarm upon intrusion detection. A POSA would understand that changes in light signals transmitted through a fiber optic cable due to physical manipulation or movement can be analyzed to detect intrusion and trigger an alarm.
  • Using optical communication components to monitor more fibers than sources/sensors: While neither G2 Systems nor Arbus Inc. explicitly detail the specific multiplexing or looping techniques of US7706641, the concept of efficiently monitoring multiple points with fewer detection units is a common engineering goal, particularly in sensor networks to reduce cost and complexity. A POSA would be motivated to explore methods to optimize resource utilization in a fiber optic sensing system, such as looping the monitor light or using multiplexing, given the understanding of optical communication components available at the time.

Combination 2: US5680104A (Volution) in view of US6967584B2 (Senstar-Stellar)

• Volution (US5680104A): This patent describes a fiber optic security system. The abstract mentions an emitter, detector, and a sensing coupler (photon switch) that, when tampered with, causes misalignment of optical fiber ends and triggers an alarm. This clearly teaches an intrusion detection system using fiber optics with an alarm.

• Senstar-Stellar (US6967584B2): This patent describes an integrated sensor cable for ranging. Senstar-Stellar is also known for perimeter intrusion detection systems using buried cables that detect disturbances and locate intrusions. While US6967584B2 specifically focuses on ranging, other Senstar-Stellar systems are broadly relevant to intrusion detection and localization in fiber optic cables.

• Motivation for Combination: Volution already provides a fiber optic security system, but it relies on a discrete "sensing coupler." A POSA would be motivated to integrate the "sensing along the length of the fiber" concept, as understood in the art of distributed fiber optic sensing (e.g., as applied by Senstar-Stellar in other contexts), with Volution's security system. The goal would be to achieve more continuous and comprehensive monitoring over the entire length of the cable rather than just at discrete points. This is driven by the desire for more robust and cost-effective security for long perimeters.

• Obviousness Argument for Claim 8 (Locating Arrangement):

  • Core elements as in Claim 1: Volution teaches the fundamental elements of a fiber optic intrusion detection system (source, sensor, alarm).
  • Locating arrangement for detected movement: Senstar-Stellar's various intrusion detection systems (e.g., FiberPatrol FP1150, RaySense) are explicitly designed to detect and locate intrusions along the length of a fiber optic cable with a certain resolution. The concept of using time-domain reflectometry or similar techniques to pinpoint the location of an event along a fiber was well-established in the art (e.g., OTDR) and readily adaptable for security purposes.
  • Stored table of fiber lengths to determine which fiber moved: Given that distributed fiber optic sensors are capable of providing location information (e.g., within meters), a POSA would find it obvious to use a stored table or map of fiber lengths and their physical arrangement to correlate a detected location with a specific fiber in a multi-fiber cable. This is a straightforward data management task once location data is available.

Combination 3: US20040071382A1 (Rich) in view of common knowledge of WDM and multiplexing

• Rich (US20040071382A1): This application describes a fiber optic security sensor and system with integrated secure data transmission and power cables. This reference teaches using fiber optics for security and integrating it with data transmission. It specifically mentions a "multi-function security cable with optic-fiber sensor" (as does US20040114888A1, a related application cited in US7706641).

• Common knowledge of WDM and multiplexing: Wavelength Division Multiplexing (WDM) was a well-known technology in optical communications prior to the priority date of US7706641. It allows multiple optical signals at different wavelengths to be transmitted simultaneously over a single optical fiber.

• Motivation for Combination: Rich teaches the desire to combine security sensing with data transmission over the same fiber optic cable. A POSA would understand that to transmit both a monitoring signal and a data signal simultaneously over a single fiber without interference, wavelength division multiplexing (WDM) is a standard and effective technique. The motivation is to maximize the utility of existing fiber infrastructure and avoid the need for separate fibers or cables for monitoring and data, thereby reducing cost and complexity.

• Obviousness Argument for Claim 9 (WDM for separating signals):

  • Core elements as in Claim 1: Rich's disclosure covers the fundamental fiber optic sensing elements.
  • Plurality of WDMs at entry and exit ends: Given the goal of simultaneous data and monitoring signal transmission on the same fiber (as taught by Rich), and the well-known utility of WDMs for combining and separating different wavelength signals, it would be obvious to a POSA to employ WDMs at both ends of each monitored fiber. This allows the monitoring signal (e.g., at a specific wavelength) to be multiplexed with the data signal at the entry end and then demultiplexed at the exit end for analysis, and similarly for looped-back monitoring signals. Various fiber optic sensing systems also leverage different wavelengths for different sensors on a single fiber.
  • Separating light from source from data signal: This is the primary function of WDM in this context and would be a direct application of existing technology to the problem presented by Rich.

General Motivation for combining references:

The problem addressed by US7706641 is the cost-effective monitoring of multiple fibers in an optical cable for intrusion. Prior art demonstrates a clear trend in fiber optic sensing towards:

• Continuous and localized monitoring: Moving beyond simple break detection to pinpoint disturbances along the fiber.
• Efficiency in resource utilization: Acknowledging the cost of dedicated monitoring systems per fiber.
• Integration of security with data transmission: Maximizing the functionality of existing fiber infrastructure [cite: 20040071382A1].

A POSA would be motivated to combine these known elements and principles to create a more sophisticated and economical fiber optic intrusion detection system. The "sophistication of the technology" and the "rapidity with which innovations are made" in the field of fiber optics would further drive such combinations. For example, the use of passive jumpers to loop a single source through multiple fibers, effectively treating them as one long fiber for monitoring, is a simple, cost-effective way to extend the reach of a single monitoring unit. Similarly, the use of unique wavelength combinations to identify specific fibers (as in Claim 6/7) is an application of established multiplexing principles to the problem of fiber identification. The various listed prior art references, individually and in combination, teach or suggest the core elements and their functions, and the motivation to combine them would stem from the desire to create more comprehensive, cost-effective, and functional fiber optic intrusion detection systems.