UNITED STATES PATENT AND TRADEMARK OFFICE
`
`____________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`_____________________
`
`ZTE (USA) INC., HTC CORPORATION, HTC AMERICA,
`SAMSUNG ELECTRONICS CO., LTD., and SAMSUNG ELECTRONICS
`AMERICA, INC., Petitioners,
`
`v.
`
`Evolved Wireless LLC,
`
`Patent Owner
`
`_____________________
`Case IPR2016-00757 1
`Patent 7,881,236 B2
`
`_____________________
`
`Declaration of Todor Cooklev, Ph. D.
`
`
`
`
`
`
`
`
`1 IPR2016-01345 has been consolidated with this proceeding.
`
`

`

`CONTENTS
`
`
`I.
`Introduction ........................................................................................................................ 3
`II.
`Qualifications ...................................................................................................................... 4
`III.
`Scope and Summary of opinions ................................................................................ 6
`IV.
`Legal standards ................................................................................................................. 6
`A.
`Presumption of Validity .................................................................................... 7
`B.
`Anticipation ............................................................................................................ 7
`C.
`Obviousness ........................................................................................................... 9
`V.
`Level of Ordinary Skill in the Art ............................................................................. 13
`VII. Overview of the technology ....................................................................................... 15
`A.
`Overview of the LTE Prior Art System ...................................................... 15
`B.
`Acquiring Radio Resources—UL Grants .................................................. 19
`C.
`HARQ ....................................................................................................................... 21
`D.
`Contention-based Random Access Procedures .................................... 24
`E.
`The four phases of the Random Access Procedure ............................. 25
`1.
`Phase 1 – Random Access preamble ............................................. 25
`2.
`Phase 2 – Random Access Response (RAR) ............................... 26
`3.
`Phase 3 – msg3 ....................................................................................... 27
`4.
`Phase 4—Contention Resolution, msg4 ...................................... 28
`VIII. Overview of the ‘236 patent ......................................................................................... 30
`Validity ................................................................................................................................ 35
`IX.
`The 321 reference.............................................................................................. 35
`A.
`1.
`Dr. Min’s analysis of the penultimate limitation of
`claim 1 is incorrect ............................................................................... 37
`The prior art 321 document does not employ the If-
`2.
`Then-Else construct relevant to the penultimate claim
`limitation, but claim 1 of the ‘236 patent does ......................... 39
`The 300 reference.............................................................................................. 51
`B.
` 2
`
`
`
`Exhibit 2006-002
`
`

`

`
`
`I.
`
`INTRODUCTION
`
`1. My name is Todor Cooklev. I have been retained by Evolved
`
`Wireless LLC (“Evolved Wireless” or “Evolved”).
`
`2.
`
`I have been asked to prepare this Declaration in connection with
`
`Case No. IPR2016-00757 (consolidated with IPR2016-01345) for inter
`
`partes review of U.S. Patent No. 7,881,236 (“the ‘236 patent’) and the
`
`Declaration of Dr. Paul Min (“the Min Declaration”). I understand that Dr.
`
`Paul Min has been retained by ZTE (USA) Inc., HTC Corporation, and
`
`HTC America, Inc., (collectively “Petitioners”) to determine if the ‘236
`
`patent’s claims are invalid. See Min Declaration at ¶ 1. I have been asked
`
`to consider the opinions of Dr. Min, and provide my opinions regarding the
`
`validity of the ’236 patent’s claims.
`
`3.
`
`I base my Declaration on information currently available to me.
`
`I reserve the right to continue my investigation. I further reserve the right
`
`to expand, modify, and/or supplement this Declaration and my opinions as
`
`additional information becomes available to me.
`
`4.
`
`In this Declaration, I cite to various documents and testimony.
`
`These citations are meant to be exemplary, and not exhaustive. Citations
`
`to documents or testimony are not intended to signify that my conclusions
`
` 3
`
`Exhibit 2006-003
`
`

`

`
`
`or opinions are limited to the cited sources, or supported by the cited
`
`sources only.
`
`II. QUALIFICATIONS
`5. My qualifications are stated more fully in my Curriculum Vitae,
`
`a copy of which is attached hereto as Appendix 1.
`
`6.
`
`I have a Ph.D. in electrical engineering from Tokyo Institute of
`
`Technology in 1995. Currently I work as the Founding Director of the
`
`Wireless Technology Center at Indiana University-Purdue University Fort
`
`Wayne and hold an endowed faculty position as Harris Chair of Wireless
`
`Communication and Applied Research.
`
`7.
`
`I have received research funding from the National Science
`
`Foundation (NSF), the U.S. Air Force Research Laboratory, the Defense
`
`Advanced Research Projects Agency (DARPA), and several major
`
`companies such as Raytheon, Harris (formerly ITT), France Telecom, and
`
`other smaller technology companies.
`
`8.
`
`I am a named inventor on thirty (30) patents issued in the
`
`United States relating to the design of integrated circuits for wireless
`
`communications systems. I have also authored and co-authored more than
`
` 4
`
`Exhibit 2006-004
`
`

`

`
`
`100 peer-reviewed articles. (A list of my publications and patents appears
`
`in my Curriculum Vitae attached as Appendix 1.)
`
`9.
`
`I received a 1994 Asia-Pacific Conference on Circuits and
`
`Systems Best Paper Award and a 2012 IEEE Standards Association award
`
`for “outstanding contributions to IEEE 802.11aa.”
`
`10. I have experience working on the design of integrated circuits
`
`(“ICs”) for wireless communication systems implementing algorithms of
`
`the types that are at issue in this investigation.
`
`11. I have been actively involved in professional organizations, in
`
`particular relevant to standards for wireless communications systems. I
`
`have served the IEEE Standards Association in several capacities,
`
`including as the first Chair of the IEEE Standards Education Committee
`
`during 2006-2007.
`
`12. I have served on standards committees, such as IEEE 802 and
`
`3GPP, and have directly contributed to the development of several
`
`standards for communications systems. I have chaired a number of
`
`standards committee meetings and served in other leadership roles. In
`
`particular, I have attended meetings of 3GPP, and have prepared
`
`documents submitted to 3GPP.
`
` 5
`
`Exhibit 2006-005
`
`

`

`
`
`13. I have served as an expert in connection with several patent
`
`litigation cases involving various communications technologies. A list of
`
`the litigations in which I have served as an expert appears in my
`
`Curriculum Vitae attached as Appendix 1.
`
`III.
`
`SCOPE AND SUMMARY OF OPINIONS
`
`14. As explained below, in my opinion the ’236 patent’s claims are
`
`valid. Accordingly, I disagree with Dr. Min’s opinions and conclusions to
`
`the contrary.
`
`15. In reaching my opinions, I reviewed: 1) the materials identified
`
`in this Declaration, 2) Dr. Min’s Declaration, including the materials
`
`considered therein. I have also relied on my personal knowledge and
`
`experience in the 3GPP’s standards development process and procedures,
`
`and the ’236 patent’s relevant field of invention.
`
`IV. LEGAL STANDARDS
`16. I am not an attorney and I will offer no opinions on the law. I
`
`am, however, informed by Evolved’s counsel of the legal standards
`
`regarding validity. I have applied these legal standards to the facts,
`
`circumstances, and materials considered, along with my experience, in
`
`arriving at my stated conclusions in this declaration.
`
` 6
`
`Exhibit 2006-006
`
`

`

`
`
`A.
`
`Presumption of Validity
`
`17. It is my understanding that the claims of an issued U.S. patent
`
`are presumed valid. I further understand that the party challenging a patent
`
`claim’s validity bears the burden of proving that claim invalid by clear and
`
`convincing evidence.
`
`18. I understand that clear and convincing evidence is a standard
`
`greater than a preponderance of the evidence, i.e., more likely than not, and
`
`less than the standard of beyond a reasonable doubt applicable in criminal
`
`cases. I have been informed that clear and convincing evidence is
`
`evidence demonstrating that the thing to be proved is highly probable or
`
`reasonably certain.
`
`B.
`
`Anticipation
`
`19. I understand that a prior art reference anticipates a patent claim
`
`only if the reference discloses all elements of the claim arranged as in the
`
`claim. I understand this means that every limitation of a claim must be
`
`disclosed expressly or inherently in a single prior art reference for the
`
`reference to anticipate the claim.
`
`20. I understand that a reference inherently discloses an element if
`
`that element is necessarily present in the disclosure of the reference and
`
`would be so recognized by persons of ordinary skill. I further understand
`
` 7
`
`Exhibit 2006-007
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`

`

`
`
`that the possibility that an element may result from a certain set of
`
`circumstances – that is, an element might be present – is not sufficient to
`
`establish inherency.
`
`21. I further understand that in order for a prior art reference to be
`
`anticipating it must be enabling to one of ordinary skill in the art. That
`
`means that the reference must enable one of ordinary skill in the art to
`
`practice an embodiment of the prior art invention without undue
`
`experimentation.
`
`22. I have been informed that, although anticipation cannot be
`
`established through a combination of references, additional references may
`
`be used to interpret the allegedly anticipating reference by, for example,
`
`indicating what the allegedly anticipating reference would have meant to
`
`one of ordinary skill in the art. For the claim to be anticipated, however,
`
`these other references must make clear that the missing descriptive matter
`
`in the patent claim is necessarily or implicitly present in the allegedly
`
`anticipating reference, and that it would be so recognized by one of
`
`ordinary skill in the art.
`
` 8
`
`Exhibit 2006-008
`
`

`

`
`
`C.
`
`Obviousness
`
`23. I have been informed that a patent claim is invalid as obvious if,
`
`at the time the invention was made, it would have been obvious to one of
`
`ordinary skill in the art in light of the teachings of the relevant prior art. I
`
`have been informed that the analysis of obviousness involves determining
`
`the scope and content of the prior art, the differences between the prior art
`
`and the claimed invention, the level of ordinary skill in the art at the time
`
`of the invention, and whether the differences are such that the claimed
`
`invention as a whole would have been obvious to one of ordinary skill in
`
`the art at the time the invention was made.
`
`24. I understand that multiple references can be combined with one
`
`another, or with the knowledge of a person of ordinary skill in the art, to
`
`render a claim obvious. However, obviousness is not established simply
`
`because all of the elements of a patent claim can be found in the prior art. I
`
`understand that it is impermissible to use hindsight reconstruction or the
`
`invention itself as a roadmap to pick and choose among disclosures in the
`
`prior art to reconstruct the claimed invention.
`
`25. I have been informed that, in seeking to determine whether an
`
`invention that is a combination of known elements would have been
`
` 9
`
`Exhibit 2006-009
`
`

`

`
`
`obvious to a person of ordinary skill in the art at the time of the invention,
`
`one must consider the references in their entirety to ascertain whether the
`
`disclosures in those references would have rendered the combination
`
`obvious to skilled artisans.
`
`26. In addition, it is my understanding that it will often be
`
`necessary to look to interrelated teachings of multiple references, the
`
`effects of demands known to the design community or present in the
`
`marketplace, and the background knowledge possessed by a person of
`
`ordinary skill in the art in order to determine whether there was an
`
`apparent reason to combine the known elements in the fashion claimed by
`
`the patent at issue.
`
`27. I understand that any need or problem known in the field of
`
`endeavor at the time of invention and addressed by the patent can provide a
`
`reason for combining the elements in the manner claimed. I understand
`
`that when a work is available in one field of endeavor, design incentives
`
`and other market forces can prompt variations of it, either in the same field
`
`or a different one. I understand that the combination of familiar elements
`
`according to known methods may be obvious when it does no more than
`
`yield predictable results. I also understand that a claim is not invalid as
`
` 10
`
`Exhibit 2006-010
`
`

`

`
`
`obvious if it is more than the predictable use of prior art elements
`
`according to their established functions.
`
`28. I understand that if a technique has been used to improve one
`
`device, and a person of ordinary skill in the art could recognize that it
`
`would improve similar devices in the same way, application of the
`
`technique to similar devices is likely to be obvious unless its actual
`
`application in that context is beyond his or her skill. I understand that if
`
`design needs or market pressures urge solution to a problem, and there are
`
`a finite number of identified, predictable solutions, then a person of
`
`ordinary skill has good reason to pursue the known options (i.e., obvious to
`
`try). I understand that under these circumstances, the combination of
`
`elements of prior art may be considered a matter of common sense and
`
`may demonstrate obviousness.
`
`29. In addition, I understand that the following rationales are also
`
`acceptable justifications to conclude that a claim would have been obvious:
`
`the claimed invention is a simple substitution of one known element for
`
`another to obtain predictable results; the combinations were within the skill
`
`and understanding of a person of ordinary skill in the art; there is some
`
`teaching, motivation, or suggestion in the prior art references themselves
`
` 11
`
`Exhibit 2006-011
`
`

`

`
`
`that would have led one of ordinary skill to modify the prior art reference
`
`or to combine prior art references to arrive at the claimed invention; the
`
`applicant admitted the feature existed in the prior art.
`
`30. I understand that if the prior art teaches away from combining
`
`known elements in the manner claimed by the invention at issue,
`
`discovering a successful way to combine them is less likely to be obvious.
`
`I also understand that similar subject matter may not be sufficient
`
`motivation for a person of skill in the art to combine references if the
`
`references have conflicting elements.
`
`31. I understand that a motivation to conduct further testing or
`
`research that may lead to the claimed invention does not necessarily render
`
`a claim obvious. I further understand that an invention is not necessarily
`
`rendered obvious simply because it was obvious to try a certain
`
`combination.
`
`32. I understand that an improper standard for obviousness is that a
`
`non-obvious invention must produce a "synergistic" result, i.e., the claimed
`
`invention must produce a result that is greater than the sum of its parts.
`
`Another improper standard for obviousness is focusing on each of the
`
`individual features of the invention and not on the invention as a whole.
`
` 12
`
`Exhibit 2006-012
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`

`

`
`
`V.
`
`LEVEL OF ORDINARY SKILL IN THE ART
`
`33. Dr. Min opines that a person having ordinary skill in the art of
`
`the subject matter of the ‘236 patent would have had a master's degree in
`
`electrical engineering with 2-3 years of experience
`
`in cellular
`
`communication systems, and would have been aware of the efforts of the
`
`Third Generation Partnership Project ("3GPP") and its various groups.
`
`Alternatively, he states that that person would have had a Ph.D. in
`
`electrical engineering with the same familiarity with the work of the 3GPP
`
`and its various groups. See Min Declaration at ¶ 34. I am familiar with the
`
`knowledge and capabilities of one or ordinary skill in this area based on
`
`my experience working with industry, with undergraduate and graduate
`
`students, with colleagues from academia, and with engineers practicing in
`
`the industry. I do not disagree with Dr. Min’s proposed level of ordinary
`
`skill in the art.
`
`
`
`VI. WHAT DO STANDARDS MEAN TO A PHOSITA
`
`34.
`
`A technology standard represents a set of rules. Standards such
`
`as the 3GPP standards are to be implemented in hardware, software, or
`
`combination of hardware and software. A PHOSITA would understand that
`
`implementations of these standards – whether in hardware or software - must
`
` 13
`
`Exhibit 2006-013
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`

`

`
`
`
`
`be consistent. Consistent behavior happens when, a given a set of inputs
`
`defined by the standard always produces the same outputs. An implementation
`
`that from the same inputs, does not always produce the same outputs is not
`
`compliant with the standard. A deviation can only be due to circumstances not
`
`contemplated by the standard. (For example, a circumstance not contemplated
`
`by the 321 standard is the device’s battery level falling below a certain
`
`minimum level required for operation).
`
`35.
`
`Standards are documents written in the English language.
`
`However, standards such as the 321 reference will be implemented in
`
`hardware and/or software. Therefore, a PHOSITA would understand that if-
`
`then statements and algorithms in the 321 reference will be implemented by
`
`if-then conditional statements. These conditional statements are very well
`
`known in virtually all computer programming languages and hardware
`
`description languages such as VHDL. Therefore "if" in the 321 reference,
`
`when part of if-then algorithms, would be understood by a PHOSITA to have
`
`the same meaning as in the if-then conditional operation. This meaning is
`
`"only if".
`
`
`
` 14
`
`Exhibit 2006-014
`
`

`

`VII. OVERVIEW OF THE TECHNOLOGY
`
`Overview of the LTE Prior Art System
`
`
`
`
`
`
`
`36. The ’236 patent is titled, “Data Transmission Method and User
`
`Equipment for the Same” and generally describes a method “for efficiently
`
`transmitting data stored in a message 3 (Msg3) buffer and a user
`
`equipment” in a mobile communication system such as the Evolved
`
`Universal Mobile Telecommunication System (“E-UMTS”), which is a
`
`Long Term Evolution (“LTE”) system developed and standardized in the
`
`3rd Generation Partnership Project (“3GPP”). Ex. 1001, Abstract, (54),
`
`1:17–32. In particular, the ’236 patent describes a random access procedure
`
`for a user equipment (UE) and a base station in such a telecommunication
`
`system. Id. at 3:42–59. Figure 1 of the ’236 patent is reproduced below.
`
`
`
` 15
`
`Exhibit 2006-015
`
`

`

`
`
`
`
`
`
`Fig. 1, Ex. 1001
`
` 37. Figure 1 is a schematic view of an E-UMTS system with core
`
`network 102 and Evolved UMTS Terrestrial Radio Network (E-UTRAN)
`
`101 including User Equipment (UE) 103, base stations eNode B 104a-n,
`
`and access gateway 105. Ex. 1001, 1:33–37. In lay language, a UE is a
`
`“mobile telephone”, “cell phone”, or another mobile computing device
`
`such as tablet that is capable of using a cellular wireless network. In its
`
`“Discussion of the Related Art,” the ’236 patent describes a random access
`
` 16
`
`Exhibit 2006-016
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`

`

`
`
`procedure for a UE to gain access to an LTE system, where the UE stores
`
`data to be transmitted in a message 3 (Msg3) buffer and transmits the data
`
`“in correspondence with” receipt from the base station of an uplink (UL)
`
`grant signal that contains information about radio resources. Id. at 3:42–44,
`
`4:18–26. According to the ’236 patent, the then-current LTE system
`
`standard provided that data stored in the Msg3 buffer of the UE would be
`
`transmitted to the base station “regardless of the reception mode of the UL
`
`Grant signal” and that “if the data stored in the Msg3 buffer is transmitted
`
`in correspondence with the reception of all UL Grant signals, problems
`
`may occur.” Id. at 4:26–32 (emphasis added). The ’236 patent purports to
`
`solve such problems. Id. at 4:33–34. Figure 9 of the ’236 patent is
`
`reproduced below.
`
`
`
` 17
`
`Exhibit 2006-017
`
`

`

`
`
`
`
`
`
`Fig. 9, Ex. 1001
`
`38. eNodeBs use various Radio Network Temporary Identifiers
`
`(RNTI) to identify UEs. The C-RNTI provides a unique UE identification
`
`at the cell level. The eNode B uses C-RNTI to provide a UE with uplink
`
` 18
`
`Exhibit 2006-018
`
`

`

`
`
`grants, for example. The eNode B also uses the C-RNTI to differentiate
`
`uplink transmissions from the different UEs.
`
`A.
`
`Acquiring Radio Resources—UL Grants
`
`39. The ‘236 patent is directed to helping a UE acquire radio
`
`resources with which to communicate with the eNode B. Initially, for
`
`example just after a UE is powered up, a UE does not have any allocated
`
`radio resources with which to transmit, i.e. it must be “scheduled” in order
`
`to transmit. More specifically, these radio resources include the time
`
`intervals and frequencies at which the UE may transmit to the eNode B.
`
`The scheduler in the base station distributes the radio resources among the
`
`UEs in the cell. The scheduler takes into account the received UEs
`
`Scheduling Requests and Buffer Status Reports, as well as the estimated
`
`channel conditions.
`
`40. There are two ways in the prior art that the UE properly
`
`receives radio resource allocation from the base station. Both involve
`
`receiving Uplink Grants (UL Grant).
`
`41. If the UE has a C-RNTI then it send a scheduling request (SR)
`
`to the base station and receive UL grants through a channel called
`
`“PDCCH” (the Physical Downlink Control Channel).
`
` 19
`
`Exhibit 2006-019
`
`

`

`
`
`42. Another way for the UE to receive an UL is to complete the
`
`random access procedure.
`
`43. A UE may request uplink resources by sending a Buffer Status
`
`Report (BSR). BSRs refer to the data that is buffered in the logical channel
`
`queues in the UE MAC.
`
`44. In LTE, data is classified into four groups, called radio bearer
`
`groups (RBG). Each RBG has data at the same priority level. The UE
`
`reports BSR per group. BSRs are triggered when (i) there is new data in a
`
`previously empty buffer; (ii) the UE has already sent a BSR and is waiting
`
`for a grant, but then higher-priority data arrives, triggering a new BSR. The
`
`higher-priority data can belong to the same RBG; (iii) BSRs can be sent
`
`periodically when a timer expires; (iv) BSRs can also be sent whenever
`
`spare space in a MAC PDU can accommodate a BSR.
`
`45. It is not strictly required that an SR or BSR report precedes the
`
`grant. When the base station believes that a mobile needs an opportunity to
`
`send data it can provide a grant to the mobile without waiting for an SR.
`
`This has the benefit of speeding up scheduling.
`
` 20
`
`Exhibit 2006-020
`
`

`

`
`
`B.
`
`HARQ
`
`46. The multiplexing/demultiplexing entity at the transmitter can
`
`multiplex data from several logical channels into one transport channel and
`
`generates MAC PDUs from MAC SDUs. The prioritization entity
`
`determines how much data and from which logical channels should be
`
`included in each MAC PDU.
`
`47. At
`
`the
`
`receiver,
`
`the multiplexing/demultiplexing entity
`
`demultiplexes the data from one transport channel into one or more logical
`
`channels and reassembles the SDUs from the PDUs.
`
`48. A MAC PDU consists of a MAC header, zero or more MAC
`
`Service Data Units (MAC SDU), zero, or more MAC control elements,
`
`and optionally padding. The header and the SDUs are of variable sizes.
`
`The C-RNTI is a 16-bit MAC control element that can be used as an
`
`identifier.
`
`49. LTE handles packet errors using two different types of
`retransmission protocols, namely ARQ (Automatic Repeat Request)
`and HARQ (Hybrid Automatic Repeat Request).
`50. The LTE HARQ protocol is a combination of FEC and ARQ.
`HARQ is based on ACK/NACKs and features soft combining based on
` 21
`
`Exhibit 2006-021
`
`

`

`
`
`Incremental Redundancy. When the
`
`receiver detects erroneous data,
`
`it sends a NACK, but doesn't discard the data. The sender will retransmit
`
`the same data again but this time, with different set of coded bits. The
`
`receiver will combine the previously received erroneous data with newly
`
`received data. This will repeat as long as the receiver is not able to decode
`
`the entire data. The advantage of this method is that with each re-
`
`transmission, the coding rate is lowered and the chances of successfully
`
`decoding the data improve. This is advantageous compared to using the
`
`same coding rate in every re-transmission. In this sense HARQ operates at
`
`the PHY layer, but requires control from the MAC layer. In this sense its
`
`operation straddles these two layers.
`
`51. There are multiple HARQ processes, each associated with a
`
`separate HARQ buffer. HARQ is Stop-and-Wait (SAW) in the sense that
`
`once a packet is sent, it waits for ACK/NACK. Since there are multiple
`
`HARQ processes, when one process is waiting for ACK/NACK, the other
`
`processes continue. Up to eight HARQ Stop-and-Wait processes can be
`
`used in parallel to speed-up transmission. This means that one process
`
`should wait 8 ms before transmitting or retransmitting again.
`
` 22
`
`Exhibit 2006-022
`
`

`

`
`
`52. The UE monitors the PDCCH at each TTI, and checks the
`
`downlink scheduling information that is received. If there is any
`
`scheduling information pertaining to the UE, data is received through the
`
`PDSCH.
`
`53. To
`
`indicate whether
`
`the
`
`transmitted data
`
`is an
`
`initial
`
`transmission or a retransmission there is a NDI (New Data Indicator). The
`
`NDI field is a one bit field that is toggled (0→1→0→1 . . .) whenever new
`
`data is transmitted, while retransmissions are indicated by the NDI field
`
`being the same as that of a previous transmission.
`
`54. In the uplink direction HARQ is synchronous. Retransmissions
`
`do not require grants transmitted on PDCCH. This reduces any waste of
`
`radio resources that would be needed if scheduling information is
`
`transmitted using the PDCCH, and eliminates problems where the UE
`
`cannot perform a retransmission because the PDCCH was not properly
`
`received.
`
`55. Retransmissions can be performed up to a maximum number. A
`
`maximum number of retransmissions is provided in order to minimize the
`
`delay that would occur if retransmission attempts were unlimited.
`
` 23
`
`Exhibit 2006-023
`
`

`

`
`
`56. The Physical HARQ Indicator Channel (PHICH) carries
`
`ACK/NACKs used in response to uplink transmissions. When a PDCCH
`
`for the UE’s C-RNTI is correctly received, the UE follows what the
`
`PDCCH asks the UE to do, i.e. perform a transmission or adaptive
`
`retransmission, regardless whether PHICH carries ACK or NACK.
`
`57. When no PDCCH addressed to the C-RNTI of the UE is
`
`detected, the HARQ feedback determines if retransmissions are performed.
`
`If NACK then the UE performs a non-adaptive retransmission. If ACK
`
`then the UE does not perform any retransmission.
`
`C.
`
`Contention-based Random Access Procedures
`
`58. In the LTE system, the random access (RA) procedures can be
`
`contention-based or contention-free. This division depends upon whether
`
`the random access preamble used during the random access procedure is
`
`selected by the UE itself or selected by the base station.
`
`59. The contention-based RA procedure is a four-phase procedure,
`
`both in the prior art and in the ‘236 patent invention, as illustrated below in
`
`Fig. 5 from the ‘236 patent (in this figure, “eNB” means “eNode B”, or
`
`base station):
`
` 24
`
`Exhibit 2006-024
`
`

`

`Fig. 5, Ex. 1001
`
`D.
`
`The four phases of the Random Access Procedure
`
`60. Next, I describe the four phases of the RA procedure, as
`
`understood in the prior art.
`
`Phase 1 – Random Access preamble
`
`1.
`61. In phase 1, the UE transmits a random access preamble (Msg1).
`
`The preamble transmission carries no data bits. The identity of the UE that
`
`sent
`
`the preamble
`
`is called RA-RNTI
`
` 25
`
`(Random access
`
`radio
`
`
`
`
`
`
`
`
`
`Exhibit 2006-025
`
`

`

`
`
`
`
`network temporary identity). The RA-RNTI is implicitly specified by
`
`the time-frequency resource used to send the preamble. Problematically,
`
`multiple UEs may transmit a RA preamble using the same time-frequency
`
`resource, meaning that they will have the same RA-RNTI.
`
`62. Contention is avoided if no two UEs that have the same RA-
`
`RNTI choose different preamble sequences.
`
`63. It is possible, however, that there is contention, i.e. two or more
`
`UEs with the same RA-RNTI choose identical preamble sequences. This
`
`may or may not mean unsuccessful preamble transmission by any of the
`
`colliding UEs. The devices will not know that a collision occurred until the
`
`fourth phase of the RA procedure (when a Contention Resolution (CR)
`
`message is transmitted. I discuss this below.)
`
`64. Preamble transmission may fail due to several reasons. Even in
`
`the absence of contention, preamble transmission may fail due to, for
`
`example, the power with which the preamble is transmitted being low.
`
`Phase 2 – Random Access Response (RAR)
`
`2.
`65. The RAR (i.e. RACH MSG 2) is transmitted via a PDSCH
`
`(Physical Downlink Shared Channel). Note that this channel is different
`
` 26
`
`Exhibit 2006-026
`
`

`

`
`
`
`
`from the PDCCH channel on which UL grants are transmitted to UEs that
`
`have C-RNTIs. (I discuss this at paragraph 41.) (It is true, though, that
`
`control information is also transferred to the UE through the PDCCH as
`
`part of the phase. This PDCCH information includes information that the
`
`UE that needs to receive the PDSCH.)
`
`66. The content of Msg2 is: (1) Random access preamble identifier;
`
`(2) Timing adjustment information; (3) UL grant for the transmission of
`
`msg3; and (4) Temporary C-RNTI.
`
`Phase 3 – msg3
`
`3.
`67. The UE transmits what is called msg3 to the network using the
`
`UL grant. In the transmission the UE applies the Time Alignment
`
`Command, and applies the temporary C-RNTI received in the RAR.
`
`68. The primary function of msg3 is to uniquely identify the UE.
`
`The reason an identifier is needed is that the temporary C-RNTI may have
`
`been assigned to more than one UEs in the RAR, due to multiple requests
`
`coming at same time. In addition to the identifier, Msg3 can include a
`
`BSR.
`
` 27
`
`Exhibit 2006-027
`
`

`

`
`
`69. The transmission of msg3 uses HARQ. The base station will
`
`send ACK or NACK using PHICH and msg3 may be retransmitted. These
`
`retransmissions are repeated until the maximum number of transmissions
`
`of msg3 is reached or until an ACK is received.
`
`70. When msg3 is transmitted, the UE starts a Contention
`
`Resolution
`
`timer. Furthermore, every
`
`time msg3
`
`is retransmitted
`
`the Contention Resolution Timer will be re-started.
`
`Phase 4—Contention Resolution, msg4
`
`4.
`71. The main purpose of msg4 is contention resolution. In the
`
`fourth phase, the eNode B echoes the identity provided by the UE in Phase
`
`3. Only the UE that finds a match between the identity received in the
`
`fourth step and the identity transmitted as part of the third step can declare
`
`the random access procedure successful, if msg4 is received before
`
`expiration of the contention resolution timer. After step 4, the successful
`
`UE can proceed with, for example, a SR.
`
`72. UEs that do not find a match between the identity received in
`
`Phase 4 and the identity transmitted as part of Phase 3 consider themselves
`
`to have failed the random access procedure and need to restart the random
`
`access procedure with Phase 1.
`
` 28
`
`Exhibit 2006-028
`
`

`

`
`
`73. If the Random Access is not successful, a UE usually has to
`
`wait certain amount of time before starting another random access attempt,
`
`which significantly increases the latency. For example, assuming the
`
`backoff window size is 50, the average backoff time would be 25ms before
`
`starting the next rand