Obviousness

Under 35 U.S.C. § 103, a patent claim is unpatentable if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (PHOSITA). The analysis requires identifying: (1) the scope and content of the prior art, (2) the differences between the prior art and the claims at issue, (3) the level of ordinary skill in the pertinent art, and (4) secondary considerations of obviousness (though none are presented here in the provided context). The motivation to combine prior art references is a crucial aspect of the obviousness analysis.

The priority date for US Patent 11516694 is July 24, 2012. Therefore, only prior art references published or publicly available before this date are relevant for an obviousness analysis.

Prior Art References Considered:

Based on the patent's own citations, the following references are relevant prior art:

1. ITU-R Recommendation P.533-10 (October 2009): "Method for the prediction of the performance of HF circuits." This document provides technical guidance for High Frequency (HF) radio propagation, including ionospheric transmission, and the factors affecting circuit performance. [cite: Non-Patent Citations]
2. US20020122468A1 (Leathrum, published September 5, 2002): "Quasi orthogonal hybrid walsh-PN codes for CDMA application in HF modems." This patent explicitly describes the use of HF modems for communication. [cite: Citations]
3. US20020164027A1 (Stephenson, published November 7, 2002): "Compression for asymmetric data links." This reference teaches data compression techniques to reduce the amount of data transmitted, thereby increasing transmission efficiency. [cite: Citations]
4. US5982813A (Wong, published November 9, 1999): "Demand-based power and data rate adjustments to a transmitter to optimize channel capacity and power usage with respect to data transmission traffic over a fixed-bandwidth channel." This patent describes adjusting transmission parameters, such as power and data rate, based on a fixed channel bandwidth. [cite: Family Cites Families]
5. US20020184645A1 (Austin, published December 5, 2002): "Measurement of quality of service." This reference discusses various Quality of Service (QoS) metrics in communication systems, including delay, which is a key component of message latency. [cite: Citations]
6. Guimaraes, Dayan Adionel (December 9, 2006): "Contributions to the Understanding of the MSK Modulation." This publication provides details on Minimum Shift Keying (MSK) modulation, a specific modulation type mentioned as potentially suitable in US11516694. [cite: Non-Patent Citations]

Obviousness Analysis of Independent Claims (Claims 1, 8, and 13)

The independent claims (Claims 1, 8, and 13) of US11516694 center on a system and method for low-latency wireless messaging, particularly involving ionospheric High Frequency (HF) transmission, message encoding for latency reduction, and determining transmission parameters based on both message latency and predefined channel bandwidth.

Combination: ITU-R P.533-10, US20020122468A1, US20020164027A1, US5982813A, US20020184645A1, and Guimaraes.

A PHOSITA in wireless communication, particularly those specializing in HF radio systems and data optimization, would have found the claimed inventions obvious by combining the teachings of these references by July 24, 2012. The pervasive commercial motivation for low-latency communication, especially for high-frequency trading (HFT) as explicitly noted in the patent, would drive a PHOSITA to combine existing techniques to minimize delays. [cite: US11516694B1, Description]

1. Claim 1: A method for ionospheric Radio Frequency (RF) transmission of a message in a High Frequency (HF) band to a remote receiving device.

• "receiving a request to transmit a particular message to the remote receiving device;"

  • This is a fundamental and well-known step in any communication system. Wireless communication networks broadly teach receiving messages for transmission, as exemplified by prior art like US6104712A, "Wireless communication network including plural migratory access nodes" [cite: Citations]. It would be obvious to a PHOSITA to initiate a communication by receiving a message.

• "encoding the particular message using a format derived to effect message latency into an encoded message for transmission on a frequency in an ionospheric HF frequency band, wherein the encoded message is known a priori to the remote receiving device as corresponding to the particular message, and wherein the encoded message is smaller than the particular message;"

  • Ionospheric HF frequency band transmission: The use of the HF spectrum for long-distance communication via ionospheric propagation was well-established. ITU-R P.533-10 provides detailed methods for predicting the performance of "HF circuits," directly addressing ionospheric transmission [cite: Non-Patent Citations]. US20020122468A1 (Leathrum) further teaches "CDMA application in HF modems," confirming the use of HF for data communication [cite: Citations].
  • Encoding for latency reduction (smaller message) and a priori knowledge: Reducing message size to decrease transmission time (i.e., message latency) is a known technique in data compression. US20020164027A1 (Stephenson) teaches "Compression for asymmetric data links" to improve transmission efficiency, which inherently reduces the time required to transmit the message [cite: Citations]. The concept that an encoded message is "known a priori to the remote receiving device" is an inherent requirement for any successful data compression or coding scheme, enabling the receiver to properly decode the message. This is explicitly recognized in the patent itself [cite: US11516694B1, Description].
  • Motivation: A PHOSITA seeking to improve speed and efficiency over established HF ionospheric links (as taught by ITU-R P.533-10 and Leathrum) would be motivated to incorporate data compression techniques (as taught by Stephenson) to reduce message size and thus message latency. The shared knowledge of the encoding scheme is a basic principle for implementing such compression.

• "determining transmission parameters for transmission of the encoded message in the ionospheric HF frequency band based at least on (a) message latency and on (b) a predefined channel bandwidth;"

  • Determining transmission parameters based on predefined channel bandwidth: Adaptive communication systems that adjust parameters based on channel characteristics are common. US5982813A (Wong) teaches "Demand-based power and data rate adjustments to a transmitter to optimize channel capacity and power usage with respect to data transmission traffic over a fixed-bandwidth channel" [cite: Family Cites Families]. This directly discloses determining transmission parameters (power, data rate) based on a "fixed-bandwidth channel," which is equivalent to a "predefined channel bandwidth."
  • Determining transmission parameters based on message latency: Optimizing communication for performance metrics like latency is a known goal in communication system design. US20020184645A1 (Austin) teaches "Measurement of quality of service," including network delay, which directly relates to message latency [cite: Citations]. Furthermore, the detailed description of US11516694 discusses calculating time-of-flight (a major component of propagation latency) based on various factors, including carrier frequency and elevation angle [cite: US11516694B1, Description]. Such calculations are implicitly or explicitly found in resources like ITU-R P.533-10, which provides methods for predicting HF circuit performance. The patent also lists specific modulation types (MSK, OOK, PSK, etc.) as transmission parameters [cite: US11516694B1, Description], and Guimaraes specifically discusses MSK modulation [cite: Non-Patent Citations].
  • Motivation: Given that HF ionospheric channels (from ITU-R P.533-10 and Leathrum) are dynamic and subject to bandwidth limitations, a PHOSITA would be motivated to adapt transmission parameters to achieve optimal performance. Wong provides the framework for adjusting parameters based on bandwidth. Recognizing the critical importance of minimizing delay (latency) in applications like HFT, as acknowledged in the patent, a PHOSITA would find it obvious to use message latency (as a QoS metric, per Austin) as an explicit basis for determining transmission parameters, alongside channel bandwidth constraints. This is a common engineering trade-off for optimizing communication systems.

• "transmitting the encoded message over the frequency in the ionospheric HF frequency band using the determined transmission parameters."

  • This step is the direct application of the determined parameters (frequency, modulation, power, etc.) for transmission over the specified HF ionospheric band, a conventional function of any HF radio system (e.g., using HF modems as in Leathrum) [cite: Citations].

2. Claim 8: A device for transmitting messages to a remote receiving device.

This claim defines a device (comprising at least one memory and at least one processing circuit) configured to perform the method steps outlined in Claim 1. Since the method steps of Claim 1 are obvious in view of the prior art, it would be obvious to a PHOSITA to implement these steps using standard computing and communication hardware. The architecture of such devices for wireless communication is widely known, as seen in general wireless communication frameworks (e.g., US20050203673A1, "Wireless communication framework") [cite: Family Cites Families]. The "front end unit," "controller," and "transmitter" described in US11516694 are functional blocks that a PHOSITA would implement using conventional processors, memory, and radio components.

3. Claim 13: A device, comprising: at least one memory and at least one processing circuit, wherein the at least one memory and the at least one processing circuit are respectively configured to store and execute instructions for causing the device to perform operations for transmitting messages to a recipient device.

This claim is substantially similar to Claim 8, with the primary difference being that the device "receives an encoded message" rather than performing the initial encoding itself. This distinction does not introduce a non-obvious feature. A PHOSITA would understand that a device transmitting messages could either perform the encoding internally or receive already encoded messages for transmission. The underlying principles of low-latency encoded messages, ionospheric HF transmission, and parameter determination based on latency and bandwidth remain the same, and these aspects are rendered obvious by the combination of prior art discussed for Claim 1.

Motivation for a PHOSITA to Combine the References:

The overarching motivation for a PHOSITA to combine these prior art references would be to develop more efficient, faster, and reliable long-distance wireless communication systems, especially for applications where latency is critical. The patent itself highlights the immense value of even microseconds of latency reduction in fields like High Frequency Trading (HFT) [cite: US11516694B1, Description]. Given this strong commercial imperative, a PHOSITA would be driven to:

• Utilize established long-distance HF ionospheric communication techniques (ITU-R P.533-10, Leathrum).
• Employ known data compression methods (Stephenson) to reduce the message size and thus improve transmission speed.
• Implement adaptive transmission parameter determination (Wong) to efficiently use bandwidth, and extend this adaptation to explicitly minimize latency (Austin's QoS metrics), as these are common, often conflicting, optimization goals in wireless communication.
• Select appropriate modulation schemes (Guimaraes) compatible with HF channels and desired data rates.

The combination of these known elements to solve known problems (latency and bandwidth constraints in wireless communication) for a well-understood commercial need (high-speed data transfer, e.g., for HFT) would have been obvious to a PHOSITA at the time of the invention.