Obviousness

To analyze the obviousness of US patent 8031654 under 35 U.S.C. § 103, we must consider whether the claimed invention, as a whole, would have been obvious to a person having ordinary skill in the art (PHOSITA) at the time of the invention (i.e., before the priority date of August 16, 2006). This involves identifying prior art references that teach elements of the claims and articulating a motivation to combine those references.

A PHOSITA in the context of US8031654 would be an individual with knowledge of wireless communication systems, specifically 3rd Generation Partnership Project (3GPP) cellular systems (such as UMTS, HSDPA, HSUPA), Internet Protocol (IP) and Transmission Control Protocol (TCP) standards, including TCP flow control and acknowledgment mechanisms, and resource allocation and scheduling in wireless networks.

Independent Claims Overview

The independent claims of US8031654 (Claims 1, 5, 9, 12, 16, 17, 21, 22, 23, 24) center on a mechanism to reduce latency in TCP-based data transfers over wireless "request and allocate" systems. The core inventive concept involves a network-side scheduler proactively allocating uplink (UL) resources for anticipated stand-alone TCP Acknowledgement (ACK) data segments. This allocation is based on counting the number of downlink (DL) TCP data segments transmitted to a wireless subscriber communication unit (UE), particularly in the context of TCP's "delayed ACK" feature. When a predetermined number of DL segments are sent, the network includes the UL resource allocation for the ACK within the downlink allocation message sent to the UE, thus eliminating the need for the UE to send a separate UL resource request and await a separate allocation.

Prior Art Combination for Obviousness

The following combination of prior art references would render the claims of US8031654 obvious to a PHOSITA:

1. WO2005002148A1 (Ipwireless, Inc.) – "Method and arrangement for TCP flow control"
2. US20050054347A1 (Kakani Naveen Kumar) – "Uplink resource allocation"
3. RFC 1122 (Braden, R. ed.) – "Requirements for Internet Hosts—Communication Layers"

Teachings of the Prior Art

• WO2005002148A1 (Ipwireless, Inc.): This patent application teaches a method and arrangement for TCP flow control in a mobile communication system. It describes sending TCP data to a mobile terminal, receiving acknowledgments from the mobile terminal, and managing the sending of subsequent TCP data based on these acknowledgments. This reference establishes the broad context of TCP operating over wireless links and the fundamental requirement for ACKs to maintain reliable data flow.
• US20050054347A1 (Kakani Naveen Kumar): This patent application describes managing uplink packet data transmissions in a cellular communication system. It details a "request and allocate" mechanism where a wireless terminal transmits a scheduling request for uplink resources, a base station receives the request and transmits a scheduling grant, and the wireless terminal then transmits uplink data in response to the grant. This reference clearly teaches the prevalent "request and allocate" paradigm for UL resource allocation in wireless systems, including the inherent latency associated with this multi-step process for any UL transmission.
• RFC 1122 (Braden, R. ed.): This non-patent literature, explicitly cited and discussed in US8031654, outlines requirements for Internet hosts, including TCP's "delayed ACK" functionality. Crucially, it states that "an ACK SHOULD be generated for at least every second full-sized segment, and MUST be generated within 500 msec. of the arrival of the first unacknowledged packet". This teaches the predictable nature of TCP ACK generation, specifically that an ACK is often triggered after a predetermined number (e.g., two) of full-sized downlink segments are received.

Motivation to Combine

A PHOSITA would have been motivated to combine the teachings of WO2005002148A1, US20050054347A1, and RFC 1122 to address the well-known challenges of optimizing TCP performance over wireless "request and allocate" links.

1. Problem Recognition: The PHOSITA would recognize that in wireless "request and allocate" systems (as taught by US'347), any uplink transmission, including small but frequent TCP ACKs, incurs significant latency due to the signaling overhead of requesting and allocating resources. This latency is exacerbated in bulk data transfers where the flow of ACKs is critical for maintaining the TCP congestion window and overall throughput. The background of US8031654 explicitly highlights this "significant latency 350" (FIG. 3).
2. Predictability of ACKs: Concurrently, the PHOSITA, knowledgeable in TCP/IP protocols, would be aware of the "delayed ACK" mechanism described in RFC 1122, which dictates that ACKs are often generated predictably after a predetermined number of downlink segments (e.g., every second full-sized segment).
3. Motivation for Proactive Allocation: Given the predictable nature of ACK generation (RFC 1122) and the performance bottleneck caused by the "request and allocate" latency for uplink transmissions (US'347) within a TCP-enabled wireless system (WO'148), a PHOSITA would be motivated to proactively allocate uplink resources for these predictable ACKs. If the network (specifically, the scheduler managing DL transmissions) could anticipate when an ACK is due, it would be a logical and desirable optimization to include the necessary uplink resources in the downlink allocation message itself. This eliminates the latency of the UE having to explicitly request UL resources for the ACK and waiting for a separate grant.
4. Implementation Details:
   • Counting Logic: Implementing "counting logic" to track the number of transmitted DL TCP segments (as per Claim 1 and 9) is a straightforward engineering task for a PHOSITA, directly stemming from the "every second full-sized segment" rule of RFC 1122. The scheduler, already managing DL transmissions (WO'148), would incorporate this counter for each TCP flow.
   • Including UL Resources in DL Message: Modifying the downlink allocation message (taught as part of the DL data transfer in WO'148 and US'347's implicit DL signaling) to include a small, predetermined amount of UL resource for a stand-alone ACK (typically 40-60 bytes, as noted in US8031654's description) would be an obvious design choice to a PHOSITA seeking to reduce latency. This leverages existing signaling channels to embed additional useful information, thereby improving system efficiency without requiring new protocols or significant architectural changes.
   • UE-side Adaptation: The corresponding adaptation on the UE side (Claims 5, 12, 23, 24) – processing the allocation message to identify both DL and UL resources and then immediately transmitting the ACK – would be a natural and obvious consequence of the network's proactive allocation. A PHOSITA would design the UE to utilize any allocated resources efficiently.

Therefore, the combination of a TCP-aware wireless system (WO'148), the understanding of uplink "request and allocate" latency (US'347), and the predictable nature of TCP delayed ACKs (RFC 1122) would lead a PHOSITA to conceive of and implement a mechanism where the network proactively allocates UL resources for ACKs based on a count of DL segments, signaling this allocation within the downlink data message, to improve TCP throughput and reduce latency.

Conclusion

Based on the explicit teachings of WO2005002148A1, US20050054347A1, and RFC 1122, and the clear motivation to mitigate known latency issues in wireless TCP performance, the claimed subject matter of US8031654 would have been obvious to a PHOSITA at the time of the invention.