US 7953411

Here's a concise summary of US Patent 7953411:

Title: Virtual soft hand over in OFDM and OFDMA wireless communication network

Assignee: Integral Wireless Technologies LLC (Current Assignee)

• Original Assignee: ZTE USA Inc

Inventor: Mary Chion

Filing Date: June 9, 2005

Issue Date: May 31, 2011

Abstract:
The patent describes efficient handover mechanisms for OFDM and OFDMA wireless communication systems. It involves operating a mobile subscriber station (MSS) to transmit and receive a frame with only one base station while continuously monitoring communications with adjacent base stations.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: This claim describes a method for a mobile subscriber station (MSS) to perform a handover in a wireless network. The method involves the MSS, currently serviced by one base station (the "current base station"), monitoring air interface messages from several adjacent base stations. The MSS transmits and receives data only with the current base station during allocated bursts within each single frame, even while continuously monitoring other base stations. The MSS then identifies a "preferred base station" from the monitored stations based on these messages (specifically, carrier to interference plus noise ratio (CINR) values). Upon the MSS requesting a handover to this preferred base station, the network changes the serving base station from the current one to the preferred one. This change involves the MSS sending a signal identifying the preferred base station, stopping communication with the current base station, and then beginning data exchange with the preferred base station in a subsequent frame.

• Independent Claim 10: This claim also describes a method for an MSS handover in a wireless network. It focuses on the MSS maintaining an "active set" of potential transmitting base stations, but only communicating with one "current transmitting base station" per single frame. The MSS monitors all base stations in this active set while actively sending and receiving data with the current transmitting base station. Based on this monitoring, the MSS determines a "preferred transmitting base station" and informs the current transmitting base station about this preference via a fast feedback channel. Subsequently, the MSS stops communicating with the current transmitting base station and begins exchanging data with the preferred base station in a following frame.

CAFC 2026 Dockets:
As of April 26, 2026, a search of CAFC 2026 dockets for US patent 7953411 did not yield any specific results directly mentioning this patent number. The search results provided general information about scheduled cases and patent-related rulings in the Federal Circuit during 2026 but did not list any active litigation or docket entries for US7953411.

As of April 26, 2026, a search for litigation involving US Patent 7953411 reveals the following cases:

• Case 1:

  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Jurisdiction: Texas Eastern District Court [cite: The full patent text indicates "US case filed in Texas Eastern District Court" for multiple litigation entries related to this patent.].
  • Case Number: 2:26-cv-00263 [cite: The full patent text indicates "US case filed in Texas Eastern District Court" for multiple litigation entries related to this patent.].
  • Filing Date: Not specified in available search results.
  • Outcome or Current Status: Active litigation ("Critical" status is indicated by Google Patents, and the Unified Patents link confirms it as an active case).

• Case 2:

  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Jurisdiction: Texas Eastern District Court [cite: The full patent text indicates "US case filed in Texas Eastern District Court" for multiple litigation entries related to this patent.].
  • Case Number: 2:26-cv-00028 [cite: The full patent text indicates "US case filed in Texas Eastern District Court" for multiple litigation entries related to this patent.].
  • Filing Date: Not specified in available search results.
  • Outcome or Current Status: Active litigation (indicated by Google Patents).

• Case 3:

  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Jurisdiction: Texas Eastern District Court [cite: The full patent text indicates "US case filed in Texas Eastern District Court" for multiple litigation entries related to this patent.].
  • Case Number: 2:25-cv-00388 [cite: The full patent text indicates "US case filed in Texas Eastern District Court" for multiple litigation entries related to this patent.].
  • Filing Date: Not specified in available search results.
  • Outcome or Current Status: Active litigation (indicated by Google Patents).

A specific search of the CAFC 2026 dockets for US patent 7953411 did not yield any specific results directly mentioning this patent number. Similarly, general searches on Unified Patents and PACER require specific case numbers or party names for detailed docket information, which are not fully provided in the initial patent text for all plaintiffs/defendants.

Proceedings overview

There are no AIA trial proceedings on file for US Patent 7953411, according to both the USPTO Open Data Portal API and supplemental web searches. This indicates a defensive posture where the patent's claims remain untested by PTAB challenges.

Strategic summary

As of the current date, no claims of US7953411 have been challenged or invalidated through Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) proceedings at the USPTO's Patent Trial and Appeal Board (PTAB). All claims of the patent, specifically claims 1-18, remain untested by this specific avenue of post-grant challenge.

Given the absence of PTAB proceedings, the estoppel landscape under § 315(e)(2) is currently clear; no prior art grounds have been adjudicated or barred for future use by a petitioner (or their privies) against this patent in a PTAB forum. This means that all potential prior art grounds, including those that reasonably could have been raised, are technically still available for a new PTAB petition, should one be filed. The patent has also not been subject to any aggressive PTAB appeals by the patent owner, nor has a defensive aggregator like Unified Patents initiated a proceeding against it in this forum, despite being associated with litigation related to the patent.

Recommended next steps

If you are a defendant facing assertion of US7953411, the absence of PTAB activity suggests that the patent claims have not been subjected to the scrutiny of an AIA trial. This means:

• Consider a PTAB Petition: An IPR, PGR, or CBM could be a viable option to challenge the patentability of the claims based on prior art. This strategy would be particularly relevant if the asserted claims rely on subject matter that you believe is anticipated or rendered obvious by prior art.
• Timing is Key: Understand the deadlines for filing such petitions (e.g., one year from service of an infringement complaint for IPRs).
• Prior Art Search: A thorough prior art search would be crucial to identify the strongest grounds for unpatentability under §§ 102 and/or 103, as these grounds have not yet been tested.

Since there are no active, concluded, or denied PTAB proceedings for this patent, there are no specific institution decision deadlines, oral hearings, or Final Written Decisions to track. The absence of PTAB activity is a notable signal, as well-asserted patents often become targets for IPRs or other AIA trials.

Inventors

• Mary Chion: Employed by ZTE USA Inc. at the time of filing.

Original assignee

The entity named on the issued patent is ZTE USA Inc. ZTE is a major telecommunications equipment and systems company that ships a wide range of products embodying wireless communication technologies, including those related to OFDM and OFDMA. ZTE USA Inc. is a subsidiary of ZTE Corporation, which remains an active, operating company.

Assignment timeline

• 2005-08-18 (executed) / recorded 2005-09-06 — Reel 016736/0271

  • Conveyance: Assignment
  • Assignor: CHION, MARY
  • Assignee: ZTE SAN DIEGO, INC.
  • Correspondent: Not explicitly provided in source text.
  • Context: Inventor's assignment of patent rights to an affiliated corporate entity.

• 2005-08-26 (effective date) / recorded 2008-01-24 — Reel 020412/0541

  • Conveyance: Change of Name
  • Assignor: ZTE SAN DIEGO, INC.
  • Assignee: ZIMAX TECHNOLOGIES, INC.
  • Correspondent: Not explicitly provided in source text.
  • Context: Corporate name change.

• 2007-12-18 (effective date) / recorded 2008-01-24 — Reel 020412/0550

  • Conveyance: Merger (Assignment of Assignors Interest)
  • Assignor: ZIMAX TECHNOLOGIES, INC.
  • Assignee: ZTE (USA) INC.
  • Correspondent: Not explicitly provided in source text.
  • Context: Transfer of ownership due to a corporate merger.

• 2012-10-01 (executed) / recorded 2013-01-11 — Reel 029610/0713

  • Conveyance: Assignment (Assignment of Assignors Interest)
  • Assignor: ZTE (USA) INC.
  • Assignee: ZTE CORPORATION
  • Correspondent: Not explicitly provided in source text.
  • Context: Internal corporate transfer to the parent company.

• 2012-10-29 (executed) / recorded 2013-02-18 — Reel 029825/0119

  • Conveyance: Assignment (Assignment of Assignors Interest)
  • Assignor: ZTE CORPORATION
  • Assignee: YARNTON TECHNOLOGIES LLC
  • Correspondent: Not explicitly provided in source text.
  • Context: Transfer of ownership from an operating company to a potentially licensing-focused entity.

• 2024-10-10 (executed) / recorded 2024-10-10 — Reel 068868/0380

  • Conveyance: Assignment (Assignment of Assignors Interest)
  • Assignor: YARNTON TECHNOLOGIES LLC
  • Assignee: INTELLECTUAL VENTURES ASSETS 194 LLC
  • Correspondent: Not explicitly provided in source text.
  • Context: Transfer of ownership to a known patent assertion entity (NPE).

• 2024-10-15 (executed) / recorded 2024-10-16 — Reel 068920/0014

  • Conveyance: Assignment (Assignment of Assignors Interest)
  • Assignor: INTELLECTUAL VENTURES ASSETS 194 LLC
  • Assignee: INTEGRAL WIRELESS TECHNOLOGIES LLC
  • Correspondent: Not explicitly provided in source text.
  • Context: Transfer of ownership from one NPE to another, which is the current asserting entity.

Timeline diagram

timeline
    title Ownership of US 7953411
    2005 : Filed by ZTE USA Inc
         : Inventor assigned to ZTE San Diego
    2008 : ZTE San Diego renamed Zimax Tech
         : Zimax Tech merged to ZTE (USA) Inc
    2011 : Patent Issued
    2013 : ZTE (USA) Inc assigned to ZTE Corp
         : ZTE Corp assigned to Yarnton Tech LLC
    2024 : Yarnton Tech assigned to IV Assets 194 LLC
         : IV Assets 194 LLC assigned to Integral Wireless Tech LLC

NPE / troll-pattern signals

1. Shell-entity transfer

   • Present: Transfer from ZTE CORPORATION (operating company) to YARNTON TECHNOLOGIES LLC in 2012 [cite: 2013-02-18 recorded, Reel 029825/0119]. Also, the final transfer to INTEGRAL WIRELESS TECHNOLOGIES LLC, which is involved in litigation, suggests it is a licensing-only entity [cite: 2024-10-16 recorded, Reel 068920/0014].

2. Known asserter in the chain

   • Present: INTELLECTUAL VENTURES ASSETS 194 LLC, a known patent assertion entity (NPE), became an assignee in 2024 [cite: 2024-10-10 recorded, Reel 068868/0380]. INTEGRAL WIRELESS TECHNOLOGIES LLC, the current assignee, is also actively asserting this patent in the Texas Eastern District Court [cite: https://patents.google.com/patent/[US7953411](/patent/US7953411)/en (Litigation section)].

3. Repeat correspondent across the chain

   • Unclear: Correspondent information is not explicitly provided in the source text for any assignment record.

4. Cascading transfers

   • Present: The patent was transferred from Yarnton Technologies LLC to Intellectual Ventures Assets 194 LLC (executed 2024-10-10) and then, only five days later, to Integral Wireless Technologies LLC (executed 2024-10-15). These consecutive transfers occurred within a very short period in 2024 [cite: 2024-10-10 recorded, Reel 068868/0380; 2024-10-16 recorded, Reel 068920/0014].

5. Pre-litigation transfer

   • Present: The most recent assignment to INTEGRAL WIRELESS TECHNOLOGIES LLC was executed on 2024-10-15 and recorded on 2024-10-16 [cite: 2024-10-16 recorded, Reel 068920/0014]. Litigation cases citing this patent (e.g., 2:25-cv-00388, 2:26-cv-00028, 2:26-cv-00263) were filed starting in 2025. This transfer occurred within 6 months of the earliest known litigation filing date.

6. Bankruptcy fire-sale

   • Not present: There is no evidence in the provided data suggesting the original assignee or any subsequent operating company in the chain filed for bankruptcy leading to a patent sale.

7. Privateering

   • Unclear: While ZTE (an operating company) transferred the patent out of its direct ownership, there is no explicit information indicating that ZTE is directing or funding the current assertion activities.

8. Defensive aggregator (anti-NPE)

   • Not present: The patent chain terminates at Integral Wireless Technologies LLC, an entity actively engaged in patent assertion, not a defensive aggregator.

Verdict

NPE — high confidence

The assignment chain clearly exhibits multiple strong NPE signals. This includes transfers to known NPEs like Intellectual Ventures Assets 194 LLC [cite: 2024-10-10 recorded, Reel 068868/0380] and subsequently to Integral Wireless Technologies LLC, which is actively litigating the patent [cite: https://patents.google.com/patent/US7953411/en (Litigation section)]. The cascading transfers and pre-litigation timing further solidify this assessment [cite: 2024-10-10 recorded, Reel 068868/0380; 2024-10-16 recorded, Reel 068920/0014].

(Verification link: https://assignmentcenter.uspto.gov/)

To identify the most relevant prior art for US Patent 7953411, I will examine each patent citation listed in the "Patent Citations" section of the provided patent text. For each reference, I will provide the full citation, publication/filing date, a brief description, and discuss which claims of US7953411 it potentially anticipates under 35 U.S.C. § 102.

Based on the provided patent text, here are the cited prior art documents and an analysis of their potential anticipation:

Most Relevant Prior Art for US Patent 7953411

1. US6002933A

• Full Citation: US6002933A, "Inter-system soft handoff"
• Priority Date: 1997-04-29
• Publication Date: 1999-12-14
• Brief Description: This patent describes an inter-system soft handoff in a wireless communication system, where a mobile station can communicate simultaneously with base stations in different cellular systems. It focuses on procedures for setting up and tearing down communication links during soft handoff, including monitoring pilot signals from candidate base stations.
• Potential Anticipation (35 U.S.C. § 102): US6002933A describes an MSS monitoring multiple base stations and communicating with more than one simultaneously in a "soft handoff." While US7953411's core innovation is a "virtual soft hand over" where the MSS only communicates with one base station at a time but monitors others, the concept of an MSS monitoring adjacent base stations (as in claim 1, "operating the MSS...to monitor air interface messages from a plurality of adjacent base stations") and initiating a handoff based on signal quality from those stations is broadly present. However, the critical distinction in US7953411 of transmitting/receiving data with only a single base station in each single frame (Claim 1) or with only one current transmitting base station in a single frame (Claim 10) is a key difference from the simultaneous communication in a traditional soft handoff. Therefore, it likely does not fully anticipate claims 1 or 10 due to this specific limitation regarding single-base station transmission per frame.

2. EP1076465A1

• Full Citation: EP1076465A1, "Handover technique for cellular network"
• Priority Date: 1999-08-10
• Publication Date: 2001-02-14
• Brief Description: This patent describes a handover technique for a cellular network, focusing on improving the handover process by reducing signaling overhead and delay. It may involve a mobile terminal evaluating signal quality from neighboring cells.
• Potential Anticipation (35 U.S.C. § 102): Without the full text, it's difficult to determine precise anticipation. However, if EP1076465A1 teaches a mobile station actively monitoring neighbor base stations and making handover decisions based on signal quality while only communicating with a single base station at any given time for data transmission, it could potentially anticipate aspects of claims 1 and 10. The provided description is too general to definitively assess the "single base station per frame" limitation.

3. US6307849B1

• Full Citation: US6307849B1, "Method and system for changing forward traffic channel power allocation during soft handoff"
• Priority Date: 1997-09-08
• Publication Date: 2001-10-23
• Brief Description: This patent focuses on power control mechanisms during a soft handoff, where a mobile station is in communication with multiple base stations. It addresses how to adjust power on the forward traffic channel from different base stations during this multi-connection state.
• Potential Anticipation (35 U.S.C. § 102): Similar to US6002933A, this patent describes a traditional soft handoff with simultaneous communication with multiple base stations. Therefore, it does not appear to anticipate the critical limitation in claims 1 and 10 of US7953411 regarding transmitting data to and receiving data from only a single base station in each single frame.

4. US20010033600A1

• Full Citation: US20010033600A1, "Sectorized smart antenna system and method"
• Priority Date: 2000-02-28
• Publication Date: 2001-10-25
• Brief Description: This patent describes a system using sectorized smart antennas to improve communication in a wireless network, potentially affecting how signals are received and how handover decisions are made.
• Potential Anticipation (35 U.S.C. § 102): The description is too broad to assess specific anticipation of US7953411's claims. Unless it details a "virtual soft hand over" mechanism with the specific single-base station per frame transmission, it is unlikely to be fully anticipatory.

5. US20020107020A1

• Full Citation: US20020107020A1, "Method for performing hard hand-off in cellular mobile communication system"
• Priority Date: 2001-02-03
• Publication Date: 2002-08-08
• Brief Description: This patent describes a method for performing a hard handoff, which is distinct from soft handoff as it involves breaking the connection with the current base station before establishing a new one.
• Potential Anticipation (35 U.S.C. § 102): Given that US7953411 specifically addresses a virtual soft hand over and the maintenance of an active set while communicating with only one BS at a time, a hard handoff method would not anticipate the core features of US7953411, especially the continuous monitoring and fast switching without a complete break in connection.

6. US20020137516A1

• Full Citation: US20020137516A1, "Method for preventing forward telecommunication distortion in soft handoff"
• Priority Date: 2001-03-22
• Publication Date: 2002-09-26
• Brief Description: This patent focuses on mitigating distortion during a soft handoff, implying a traditional soft handoff where the mobile communicates with multiple base stations simultaneously.
• Potential Anticipation (35 U.S.C. § 102): As with other soft handoff patents that imply simultaneous connections, this reference would not anticipate the "single base station per frame" limitation of US7953411's claims 1 and 10.

7. US20020141375A1

• Full Citation: US20020141375A1, "Increasing link capacity via concurrent transmissions in centralized wireless LANs"
• Priority Date: 2001-03-30
• Publication Date: 2002-10-03
• Brief Description: This patent is directed to increasing link capacity through concurrent transmissions in wireless LANs.
• Potential Anticipation (35 U.S.C. § 102): The description does not suggest a handover mechanism in OFDM/OFDMA networks with the specific "single base station per frame" limitation of US7953411. Its focus on increasing capacity via concurrent transmissions in WLANs is distinct.

8. US20020193116A1

• Full Citation: US20020193116A1, "Network-layer and link-layer use of shadow addresses with IP-based base stations"
• Priority Date: 2001-03-30
• Publication Date: 2002-12-19
• Brief Description: This patent discusses the use of shadow addresses for IP-based base stations, which can be relevant for seamless mobility and handovers at the network and link layers.
• Potential Anticipation (35 U.S.C. § 102): While relevant to handover and mobility, the description does not disclose the specific air interface monitoring and single-base station per frame transmission aspects central to US7953411's claims 1 and 10.

9. US20030039228A1

• Full Citation: US20030039228A1, "Method & apparatus for W-CDMA handoff searching"
• Priority Date: 2001-08-22
• Publication Date: 2003-02-27
• Brief Description: This patent describes methods and apparatus for handoff searching in W-CDMA systems, including active and candidate sets of base stations.
• Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant as it describes maintaining active and candidate sets for handoff, and searching for suitable base stations. If it also discloses the specific mechanism of an MSS transmitting and receiving data from only one base station at a time while monitoring others in an OFDM/OFDMA context, it could potentially anticipate aspects of claims 1 and 10. However, the mention of "W-CDMA" suggests a different underlying air interface technology than OFDM/OFDMA, which might be a distinguishing factor for US7953411's claims 4 and 5.

10. US20030073455A1

• Full Citation: US20030073455A1, "Packet communication system with dual candidate sets for independent management of uplink and downlink transmissions"
• Priority Date: 2001-10-17
• Publication Date: 2003-04-17
• Brief Description: This patent discloses a packet communication system that uses dual candidate sets for independent management of uplink and downlink transmissions, potentially in a soft handoff context.
• Potential Anticipation (35 U.S.C. § 102): The concept of independent management for uplink and downlink could be related to the flexibility of the VSHO in US7953411. However, unless it explicitly teaches the "single base station per frame" transmission/reception coupled with monitoring in an OFDM/OFDMA system, it may not fully anticipate claims 1 or 10.

11. US6606341B1

• Full Citation: US6606341B1, "Common packet channel with firm handoff"
• Priority Date: 1999-03-22
• Publication Date: 2003-08-12
• Brief Description: This patent describes a common packet channel and a "firm handoff" process. Firm handoff is a type of controlled hard handoff where the mobile station is released from the old base station only after it successfully establishes a connection with the new one.
• Potential Anticipation (35 U.S.C. § 102): A "firm handoff" is a variation of hard handoff and does not involve the continuous monitoring and dynamic switching with an active set while maintaining a single transmission point per frame as described in US7953411. Thus, it is unlikely to anticipate claims 1 or 10.

12. US20030190915A1

• Full Citation: US20030190915A1, "Method and system for controlling radio communications network and radio network controller"
• Priority Date: 1997-08-20
• Publication Date: 2003-10-09
• Brief Description: This patent describes a method and system for controlling a radio communications network, including the functions of a radio network controller, which could involve handover management.
• Potential Anticipation (35 U.S.C. § 102): This is a very general description. Without more specific details about the handoff mechanism at the air interface and the role of the MSS in selecting a single transmitting base station per frame while monitoring others, it is unlikely to anticipate claims 1 or 10.

13. US6771963B1

• Full Citation: US6771963B1, "Triggering handdowns and handoffs of mobile stations between bordering cells of cellular wireless communication systems"
• Priority Date: 1998-08-17
• Publication Date: 2004-08-03
• Brief Description: This patent describes mechanisms for triggering handovers and handdowns (reducing the number of active connections) in cellular systems, often based on signal strength measurements.
• Potential Anticipation (35 U.S.C. § 102): While triggering handovers is central to US7953411, this reference likely describes traditional handovers. Unless it details the specific "virtual soft hand over" with single-base station per frame transmission, it will not fully anticipate claims 1 or 10. However, the concept of selecting a preferred base station based on CINR (as in claim 1) is a common element in many handover procedures and might be generally taught here.

14. US20040152483A1

• Full Citation: US20040152483A1, "Transmission power control method and system"
• Priority Date: 1999-12-13
• Publication Date: 2004-08-05
• Brief Description: This patent describes a transmission power control method and system for wireless communications.
• Potential Anticipation (35 U.S.C. § 102): Power control methods, while important for wireless systems, do not inherently disclose the specific virtual soft handover mechanism of US7953411, particularly the single-base station per frame transmission and monitoring.

15. US20040190378A1

• Full Citation: US20040190378A1, "Virtual real-time clock based on time information from multiple communication systems"
• Priority Date: 2003-03-27
• Publication Date: 2004-09-30
• Brief Description: This patent describes a virtual real-time clock based on time information from multiple communication systems. Synchronization between base stations is a condition for VSHO in US7953411 (as mentioned in the detailed description, "BSs involving in VSHO are synchronized based on a common time source").
• Potential Anticipation (35 U.S.C. § 102): While US7953411 mentions synchronization as a condition, this patent specifically teaches a method for achieving synchronization, not the handover method itself. Therefore, it might anticipate the "synchronized frames" aspect (claim 8, 17) as a general prerequisite but not the unique "virtual soft hand over" method of claims 1 and 10.

16. US20040219926A1

• Full Citation: US20040219926A1, "Method for measuring and reporting channel quality in a broadband wireless access communication system"
• Priority Date: 2003-04-30
• Publication Date: 2004-11-04
• Brief Description: This patent describes a method for measuring and reporting channel quality (e.g., CINR) in a broadband wireless access system, which is crucial for handover decisions.
• Potential Anticipation (35 U.S.C. § 102): The measurement and reporting of CINR is explicitly stated in US7953411 as a basis for selecting a preferred base station (Claim 1, 12). If this prior art teaches the use of CINR for selecting a preferred base station for handover in a system where the MSS only communicates with one base station at a time, it could potentially anticipate the specific method steps related to CINR-based selection in claims 1 and 10.

17. US20040252662A1

• Full Citation: US20040252662A1, "Method for controlling operational states of a MAC layer in an OFDM mobile communication system"
• Priority Date: 2003-06-13
• Publication Date: 2004-12-16
• Brief Description: This patent describes controlling MAC layer operational states in an OFDM mobile communication system. MAC context sharing is a feature of US7953411 (claims 9, 18).
• Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant as it explicitly mentions "OFDM mobile communication system" and "MAC layer." If it teaches sharing MAC context between base stations to facilitate a handover where an MSS communicates with only one base station at a time while monitoring others, it could potentially anticipate claims 1, 9, 10, and 18.

18. US20050192011A1

• Full Citation: US20050192011A1, "Method and apparatus for performing fast handover through fast ranging in a broadband wireless communication system"
• Priority Date: 2004-02-13
• Publication Date: 2005-09-01
• Brief Description: This patent describes performing fast handover through fast ranging in a broadband wireless communication system.
• Potential Anticipation (35 U.S.C. § 102): The concept of "fast handover" is aligned with the "fast switching mechanism" mentioned in US7953411. If this patent details an MSS monitoring multiple base stations but only transmitting/receiving data with one at a time, and making fast switching decisions, it could be highly anticipatory of claims 1 and 10. The publication date is after US7953411's priority date of June 9, 2004, so it might not be prior art in the anticipatory sense unless its priority date is earlier. However, the filing date (and implied priority date) of this reference is February 13, 2004, which is before the priority date of US7953411 (June 9, 2004). Therefore, this is a very strong candidate for prior art anticipation.

19. US20050220040A1

• Full Citation: US20050220040A1, "Method for controlling the data rate of transmitting data packets in a wireless communications system, receiver and transmitter therefor"
• Priority Date: 2002-02-14
• Publication Date: 2005-10-06
• Brief Description: This patent describes controlling the data rate of transmitting data packets in a wireless communication system.
• Potential Anticipation (35 U.S.C. § 102): Data rate control is generally applicable to wireless communication but does not appear to directly anticipate the specific virtual soft handover mechanism of US7953411, particularly the single-base station per frame transmission and monitoring aspects.

20. US20050250498A1

• Full Citation: US20050250498A1, "System and method for performing a fast handover in a broadband wireless access communication system"
• Priority Date: 2004-05-07
• Publication Date: 2005-11-10
• Brief Description: This patent describes a system and method for performing a fast handover in a broadband wireless access communication system.
• Potential Anticipation (35 U.S.C. § 102): Similar to US20050192011A1, this patent, with a priority date of 2004-05-07 (before US7953411's priority date), could be highly anticipatory if it details an MSS monitoring multiple base stations but only transmitting/receiving data with one at a time, and making fast switching decisions in a broadband wireless access system.

21. US6970708B1

• Full Citation: US6970708B1, "System and method for improving channel monitoring in a cellular system"
• Priority Date: 2000-02-05
• Publication Date: 2005-11-29
• Brief Description: This patent describes improving channel monitoring in a cellular system.
• Potential Anticipation (35 U.S.C. § 102): While US7953411 involves monitoring air interface messages (claims 1, 10), this patent is generally about improving monitoring. If it specifically teaches monitoring in the context of selecting a single transmitting base station per frame for handover in an OFDM/OFDMA system, it could be anticipatory.

22. US20050282548A1

• Full Citation: US20050282548A1, "System and method for optimizing handover in mobile communication system"
• Priority Date: 2004-06-07
• Publication Date: 2005-12-22
• Brief Description: This patent describes a system and method for optimizing handover in a mobile communication system.
• Potential Anticipation (35 U.S.C. § 102): This patent has a priority date of 2004-06-07, which is two days before the priority date of US7953411 (2004-06-09). If this patent describes an MSS operating to monitor air interface messages from multiple base stations, communicating with only one at a time for data transmission, and making handover decisions based on this monitoring, it could be highly anticipatory of claims 1 and 10 of US7953411.

23. US20060094433A1

• Full Citation: US20060094433A1, "Fast handover with reduced service interruption for high speed data channels in a wireless system"
• Priority Date: 2004-10-29
• Publication Date: 2006-05-04
• Brief Description: This patent describes fast handover with reduced service interruption for high-speed data channels in a wireless system.
• Potential Anticipation (35 U.S.C. § 102): The priority date of this patent (2004-10-29) is after US7953411's priority date (2004-06-09). Therefore, this document is not considered prior art for anticipation under 35 U.S.C. § 102 with respect to US7953411.

24. US7050802B2

• Full Citation: US7050802B2, "Cellular communication device with scanning receiver and continuous mobile communication system employing same"
• Priority Date: 1998-11-19
• Publication Date: 2006-05-23
• Brief Description: This patent describes a cellular communication device with a scanning receiver and a continuous mobile communication system, allowing monitoring of multiple channels.
• Potential Anticipation (35 U.S.C. § 102): A scanning receiver can monitor multiple base stations (as in claim 1). If this patent further details a mechanism where a mobile device uses this scanning capability to select a single base station for transmission/reception in each frame while continuously monitoring others for handover, it could potentially anticipate aspects of claims 1 and 10. The publication date is after US7953411's priority date, but the priority date is significantly earlier, making it relevant prior art.

25. US20060120490A1

• Full Citation: US20060120490A1, "Method and apparatus for coordinating transmission of short messages with hard handoff searches in a wireless communications system"
• Priority Date: 1998-05-21
• Publication Date: 2006-06-08
• Brief Description: This patent focuses on coordinating short message transmission with hard handoff searches.
• Potential Anticipation (35 U.S.C. § 102): This reference discusses hard handoff, which, as previously stated, does not align with the "virtual soft hand over" concept of US7953411 that maintains an active set and switches without a full connection break. Therefore, it is unlikely to anticipate claims 1 or 10.

26. US20060154671A1

• Full Citation: US20060154671A1, "System and method for allocating a channel quality information channel in a communication system"
• Priority Date: 2005-01-10
• Publication Date: 2006-07-13
• Brief Description: This patent describes a system and method for allocating a channel quality information channel.
• Potential Anticipation (35 U.S.C. § 102): The priority date of this patent (2005-01-10) is after US7953411's priority date (2004-06-09). Therefore, this document is not considered prior art for anticipation under 35 U.S.C. § 102 with respect to US7953411.

27. US20060182063A1

• Full Citation: US20060182063A1, "Soft handoff for OFDM"
• Priority Date: 2002-03-22
• Publication Date: 2006-08-17
• Brief Description: This patent explicitly discusses soft handoff in the context of OFDM, a technology central to US7953411.
• Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant due to its explicit mention of "Soft handoff for OFDM." However, "soft handoff" typically implies simultaneous communication with multiple base stations, which is explicitly contrasted with US7953411's "virtual soft hand over" where only one BS transmits/receives data to/from the MSS per frame. If this patent describes a traditional soft handoff where multiple base stations actively transmit data to the MSS during the handover, it would not anticipate the single-transmission-per-frame limitation in claims 1 and 10. However, if it discloses the monitoring of multiple OFDM base stations to select a single best base station for data transmission in a given frame, it could be anticipatory.

Summary of Potentially Most Relevant Prior Art (for anticipation of claims 1 and 10, specifically the "single base station per frame" limitation coupled with monitoring):

The most critical aspect for anticipation of claims 1 and 10 lies in whether any prior art teaches an MSS that:

1. Monitors air interface messages from multiple adjacent base stations.
2. Transmits data to and receives data from only a single one of the adjacent base stations in each single frame.
3. Processes messages to decide which base station to use for a frame.
4. Optionally uses CINR for selection and fast feedback channels for signaling.

Based on the brief descriptions and priority dates, the following prior art documents warrant closer examination for potential anticipation of claims 1 and 10:

• US20050192011A1 (Priority Date: 2004-02-13): Its focus on "fast handover" through "fast ranging" in a "broadband wireless communication system" with a priority date before US7953411 makes it a strong candidate. If it describes the single-transmission-per-frame mechanism, it would be highly anticipatory.
• US20050250498A1 (Priority Date: 2004-05-07): Similar to the above, this patent's focus on "fast handover in a broadband wireless access communication system" and its earlier priority date suggest it could be highly relevant if it teaches the specific VSHO mechanism.
• US20050282548A1 (Priority Date: 2004-06-07): This patent's priority date is only two days before US7953411's. Its description of "optimizing handover in mobile communication system" means it could be highly relevant if it includes the specific VSHO features.
• US20040219926A1 (Priority Date: 2003-04-30): If this patent's method for "measuring and reporting channel quality" is directly integrated into a single-transmission-per-frame handover decision, it could anticipate the CINR-based selection.
• US20040252662A1 (Priority Date: 2003-06-13): This patent is particularly relevant due to its mention of "OFDM mobile communication system" and "MAC layer." If it teaches MAC context sharing to enable the unique VSHO of US7953411, it could be highly anticipatory.
• US20030039228A1 (Priority Date: 2001-08-22): While for W-CDMA, its description of "handoff searching" with active and candidate sets could be anticipatory if it contains a teaching of single-base station per frame transmission for data with concurrent monitoring.
• US20060182063A1 (Priority Date: 2002-03-22): Explicitly discusses "Soft handoff for OFDM." The key would be whether its definition of "soft handoff" includes the "single base station per frame" data transmission model of US7953411.

For a definitive determination of anticipation under 35 U.S.C. § 102, a full claim-by-claim analysis of the complete text and drawings of each of these potentially anticipatory prior art documents would be necessary to ascertain if every element of claims 1 and 10 (and their dependent claims) is present in a single prior art reference.

Obviousness (35 U.S.C. § 103)

To determine if US Patent 7953411 is obvious under 35 U.S.C. § 103, we need to identify combinations of prior art references that would render the claims obvious and explain the motivation for a person having ordinary skill in the art (POSA) to combine them. A POSA is presumed to have knowledge of all relevant prior art and to be motivated to combine references to achieve predictable results, improve existing devices or methods, or solve known problems in the art. The motivation to combine can come from the knowledge of those skilled in the art, from the prior art reference itself, or from the nature of the problem to be solved.

The core innovation of US7953411, as seen in independent claims 1 and 10, is the "virtual soft hand over" (VSHO). This involves an MSS monitoring multiple adjacent base stations but only transmitting and receiving data from a single current base station in each frame, and then dynamically switching to a preferred base station based on monitored air interface messages (like CINR), facilitated by MAC context sharing and synchronized frames. This contrasts with traditional soft handovers (SHO) where an MSS communicates simultaneously with multiple base stations.

Here, we'll focus on combinations that address the key distinguishing features of VSHO, particularly the single-base station communication per frame during handover, coupled with continuous monitoring and fast switching in an OFDM/OFDMA context.

Combination 1: US20040252662A1 in view of US20050282548A1 and general knowledge of OFDM/OFDMA handover challenges.

• US20040252662A1 ("Method for controlling operational states of a MAC layer in an OFDM mobile communication system") explicitly discusses MAC layer control in an OFDM system [cite: US20040252662A1]. It also mentions MAC context sharing as a feature of US7953411 (claims 9, 18).
• US20050282548A1 ("System and method for optimizing handover in mobile communication system") describes optimizing handover and has a priority date just two days before US7953411 [cite: US20050282548A1]. This patent, if it details an MSS operating to monitor air interface messages from multiple base stations and making handover decisions based on this monitoring, would be highly relevant.

Motivation to Combine: A POSA would be motivated to combine these references to optimize handover procedures in OFDM/OFDMA systems. US20040252662A1 provides the foundation for MAC layer control and context sharing in an OFDM environment, which is crucial for efficient handover. US20050282548A1 aims to optimize handover, implying a desire to improve handover quality and reduce complexity, which is precisely the problem US7953411 seeks to solve with VSHO. The common problem of inefficient handover in wireless networks would drive a POSA to combine these approaches.

Reasoning for Obviousness:

• Monitoring and Selection (Claims 1 & 10): US20050282548A1, in optimizing handover, would inherently teach or suggest monitoring adjacent base stations to make handover decisions, likely based on metrics like CINR (which is a common practice, also seen in US20040219926A1).
• Single-Base Station per Frame Transmission (Claims 1 & 10): While traditional soft handovers involve simultaneous connections, a POSA, seeking to optimize handover (as in US20050282548A1) and reduce complexity and overhead (as stated in US7953411's summary), would consider alternatives to full simultaneous transmission. Given the constraints of a single-frame transmission model for data, it would be an obvious design choice to restrict actual data exchange to only the "best" or "preferred" base station at any given moment to reduce interference and synchronization overhead, while still leveraging the benefits of monitoring multiple base stations for quick switching. This design choice, in the context of improving handover, would be a predictable solution for a POSA.
• MAC Context Sharing (Claims 9 & 18): US20040252662A1 directly addresses MAC layer control in OFDM systems, and MAC context sharing is a known technique for facilitating seamless handovers by enabling different base stations to have necessary information about the MSS. The IEEE 802.16e D8 standard, which US7953411 references, also details MAC context transfer for high-mobility scenarios, indicating it was a known concept at the time. Therefore, sharing MAC context between the current and preferred base stations would be an obvious implementation detail when optimizing handover as described in US20050282548A1, especially within an OFDM system as taught by US20040252662A1.
• OFDM/OFDMA Context (Claims 4, 5, 14, 15): The explicit mention of OFDM in US20040252662A1 [cite: US20040252662A1], combined with general knowledge of OFDMA as an extension of OFDM and its application in mobile broadband (e.g., WiMAX which is based on 802.16e), would make the application of these handover optimization techniques to OFDMA systems obvious to a POSA.

Combination 2: US20050192011A1 or US20050250498A1 in view of US20040190378A1 and common wireless network synchronization techniques.

• US20050192011A1 ("Method and apparatus for performing fast handover through fast ranging in a broadband wireless communication system") [cite: US20050192011A1] and US20050250498A1 ("System and method for performing a fast handover in a broadband wireless access communication system") [cite: US20050250498A1] both describe "fast handover" in broadband wireless systems and have priority dates before US7953411.
• US20040190378A1 ("Virtual real-time clock based on time information from multiple communication systems") discusses synchronization from multiple systems, a condition for VSHO in US7953411. Other sources also confirm that network time protocol and GPS synchronization are common methods of time synchronization in both wired and wireless networks.

Motivation to Combine: A POSA seeking to implement "fast handover" (as in US20050192011A1 or US20050250498A1) would recognize the critical need for synchronized base stations to ensure smooth and efficient switching, especially to reduce service interruption. US20040190378A1 provides a method for achieving synchronization across multiple communication systems, and general knowledge in the art would point to established synchronization protocols like NTP or GPS. Therefore, a POSA would be motivated to integrate reliable synchronization techniques into a fast handover system.

Reasoning for Obviousness:

• Fast Handover and Single-Base Station (Claims 1 & 10): The primary references explicitly aim for "fast handover." To achieve a truly "fast" handover with minimal interruption, a POSA would understand that a hard break-before-make handover introduces delays. While traditional soft handover offers seamlessness, the complexity and resource overhead (especially in OFDM/OFDMA) could be undesirable. A design combining the benefits of continuous monitoring (as in soft handover) with the efficiency of single-point transmission (like a streamlined hard handover) would be an obvious improvement for speed and reduced overhead. This could lead to a system where an MSS monitors all candidate BSs but only actively communicates with one "best" BS per frame for data transmission, allowing for very rapid switching when conditions change.
• Synchronized Frames (Claims 8 & 17): US7953411 explicitly states that "BSs involving in VSHO are synchronized based on a common time source" and "BSs involving in VSHO have synchronized frames." Achieving synchronized frames between base stations is a well-known requirement for various wireless communication protocols (e.g., TDMA) and for efficient handover, especially in OFDM/OFDMA systems where timing is crucial. US20040190378A1 provides a general method for synchronization. Combining a fast handover mechanism with the established need for and methods of base station synchronization (e.g., using GPS or NTP, which are widely known for accurate time synchronization in telecommunication systems) would be an obvious step for a POSA to ensure a robust and seamless fast handover.

Combination 3: US20030039228A1 (W-CDMA handoff searching) in view of US20040252662A1 (OFDM MAC layer control) and the problem of efficient handoff in OFDM/OFDMA.

• US20030039228A1 ("Method & apparatus for W-CDMA handoff searching") describes maintaining active and candidate sets of base stations for handoff searching [cite: US20030039228A1].
• US20040252662A1 ("Method for controlling operational states of a MAC layer in an OFDM mobile communication system") applies to OFDM systems and MAC layer control [cite: US20040252662A1].

Motivation to Combine: A POSA would be motivated to adapt the known and effective handoff searching and active set management principles from W-CDMA (as taught by US20030039228A1) to the emerging OFDM/OFDMA wireless communication environment. The desire to provide efficient mobility and handover in OFDM/OFDMA systems (a known problem addressed by IEEE 802.16e development) would naturally lead a POSA to apply established handover strategies from other wireless technologies to OFDM/OFDMA, modifying them as needed for the specific air interface characteristics.

Reasoning for Obviousness:

• Active Set and Monitoring (Claims 1 & 10): US20030039228A1 already teaches the concept of active and candidate sets for handoff, and searching/monitoring neighbor base stations. This fundamental approach to handoff management is directly transferable.
• Single-Base Station per Frame in OFDM (Claims 1, 4, 5, 10, 14, 15): While US20030039228A1 is W-CDMA-centric (which uses soft handoff), a POSA adapting this to an OFDM/OFDMA system, particularly with the aim of reducing complexity and synchronization overhead (as distinct from traditional SHO), would find it obvious to modify the simultaneous communication aspect. The idea of selecting the best base station for transmission in each frame while still monitoring others for potential future switching is a logical evolution to optimize resource usage and simplify scheduling in an OFDM/OFDMA environment. US20040252662A1 provides the specific context of MAC layer control in OFDM, making such an adaptation practical. The concept of using a fast feedback channel for selection (as in US7953411 claims 3 and 10) is also a known technique for efficient communication in wireless systems.
• CINR-based Selection (Claims 1, 12): The use of CINR for selecting a preferred base station is a standard practice in wireless communication handover decisions, as seen in other prior art like US20040219926A1. A POSA would routinely employ such metrics when making handover decisions based on monitoring signals from multiple base stations.

General Motivation for Combining Prior Art in Handover Systems

The motivation to combine elements from these prior art references stems from several well-understood principles in wireless communication:

• Improving Performance: Wireless network designers constantly strive to improve handover quality, reduce latency, minimize dropped calls, and optimize resource utilization. Combining existing techniques to achieve these goals is a continuous endeavor.
• Solving Known Problems: Traditional soft handover, while offering diversity gain, introduces complexity and synchronization overhead, particularly in OFDM/OFDMA systems. A POSA would be motivated to find ways to reduce this complexity while retaining some benefits of diversity or seamlessness. The concept of a "virtual soft handover" as described in US7953411 directly addresses this problem by allowing fast switching without full simultaneous data transmission.
• Adapting to New Technologies: As new air interface technologies like OFDM and OFDMA emerged, POSAs would naturally adapt proven concepts (like active sets, channel quality monitoring, and context sharing) from older technologies (e.g., CDMA/W-CDMA) to the new platforms.
• Predictable Results: Many of the elements, such as monitoring signal strength (CINR), maintaining lists of neighbor base stations (active sets), sharing MAC context, and synchronizing base stations, were well-established in the art. Combining these elements to achieve a faster, more efficient handover is a predictable result of applying known techniques to a known problem.

Therefore, a POSA, aware of the challenges and established solutions in wireless handover, would have found it obvious to combine the teachings of these prior art references to arrive at the virtual soft handover mechanisms claimed in US7953411.