`
`,
`
`'
`
`_I
`
`CONTROLLING DATA TRANSMISSION RATE ON THE REVERSE LINK
`
`FOR EACH MOBILE STATION IN A DEDICATED MANNER
`
`FIELD OF THE INVENTION
`
`5
`
`The present
`
`invention generally relates
`
`to mobile ( or wireless)
`
`communications, and in particular, to controlling data transmission (transfer)
`
`rates between a base station and mobile stations served by the base station so
`
`that data throughput is advantageously increased.
`
`\,fo
`
`BACKGROUND OF THE INVENTION
`
`Mobile communications involve, among various processing procedures,
`
`::::;~
`
`i1~s
`
`signal transmissions and handling of data traffic between an access network
`
`(AN) and an access terminal (AT). An access network (AN) comprises many
`
`elements, one of which being a base station, as known by those skilled in the
`
`art. An access terminal (AT) can be in many forms, including a mobile station
`
`(e.g., a mobile phone), a mobile terminal (e.g., a laptop computer), and other
`
`devices (e.g., a personal digital assistant: PDA) having
`
`the combined
`
`functionality of both a mobile station and a mobile terminal, or having other
`
`terminal capabilities. Hereinafter, an access terminal (AT) will be referred to as a
`
`20
`
`"mobile" for the sake of brevity.
`
`In a conventional mobile communications system, a plurality of mobiles
`
`(e.g., cellular phones, portable computers, etc.) are served by a network of base
`
`stations, which serve to allow the mobile stations to communicate with other
`
`components
`
`in
`
`the communications system. Various
`
`types of mobile
`
`25
`
`communications systems are known, including Code Division Multiple Access
`
`1
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`Page 2 of 540
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`
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`J
`
`'
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`(CDMA), time division multiple access (TDMA), frequency division multiple
`
`access (FDMA), and various enhancements and improvements thereto which
`
`are generally referred to as next generation mobile communications systems.
`
`CDMA is most widely accepted and continues to develop and evolve. In
`
`s
`
`particular, CDMA technology evolution (such as the so-called "cdma2000"
`
`technology or other next generation CDMA systems) will provide integrated
`
`voice with simultaneous high-speed packet data, video and video conferencing
`
`capabilities. Currently, the third generation (3G) evolution of cdma2000 1X
`
`wireless communications is being reviewed or partially adopted by certain
`
`!:30
`
`standards bodies, such as 3GPP and 3GPP2
`
`(The Third Generation
`
`Partnership Project 2).
`
`For example, a baseline
`
`framework
`
`for cdma2000 1xEV-DV
`
`(1xEVolution - Data and Voice) was recently reached by the 3GPP2. The 1xEV(cid:173)
`
`DV standard will be backward compatible with existing CDMA IS-95A/B and
`
`CDMA2000 1 x systems, allowing various operators seamless evolution for their
`
`CDMA systems. Other types of systems that are evolving from CDMA include
`
`High Data Rate (HDR) technologies, 1xEvolution - Data Only (1xEV-DO)
`
`technologies, and the like, which will be explained in more detail hereinafter.
`
`The present disclosure focuses on data transmission techniques
`
`20
`
`between base stations and mobiles. Thus, a detailed description of additional
`
`components, elements and processing procedures (not specifically mentioned
`
`herein) have been omitted so that the features of the present invention are not
`
`obscured. One skilled in the art would have understood that various other
`
`components and techniques associated with base stations and mobiles already
`
`2s
`
`known in the art but not described in detail herein, are also part of the present
`
`2
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`Page 3 of 540
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`
`
`J
`
`r
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`invention. For example, specific details of the protocol architecture having an
`
`air interface with a
`
`layered structure, physical
`
`layer channels, protocol
`
`negotiation and processing, and the like have been omitted.
`
`In a communications system, a set of "channels" allow signals to be
`
`5
`
`transmitted between the access network (e.g., a base station) and the access
`
`terminal (e.g., a mobile) within a given frequency assignment. Channels consist
`
`of "forward channels" and "reverse channels."
`
`Signal transmissions (data transmissions or transfers) from the base
`
`station to a mobile via a downlink (i.e., forward channels) are commonly
`
`i:'.:io
`
`referred to as the "forward link," while signal transmissions from the mobile to
`
`the base station via an uplink (i.e., reverse channels) are commonly referred to
`
`as the "reverse link."
`
`So-called "physical layers" provide the channel structure, frequency,
`
`power output, modulation, and encoding specifications for the forward and
`
`reverse links. The "forward channels" consist of those physical layer channels
`
`;:ls
`
`l;;;::;J
`
`transmitted from the access network to the access terminal, and "reverse
`
`channels" consist of those physical layer channels transmitted from the access
`
`terminal to the access network.
`
`Of the many portions of the forward and reverse channels, the "forward
`
`20 MAC channel" is the portion of the forward channel dedicated to medium
`
`access control (MAC) activities. The forward MAC channel consists of the
`
`reverse power control {RPC) channel, the reverse activity (RA) channel, and
`
`other channels. Here, the forward MAC reverse activity (RA) channel indicates
`
`the activity level (e.g., the load) on the reverse channel.
`
`25
`
`In the so-called Interim Standard 95A (1S-95A) systems, the forward link
`
`3
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`.l
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`•
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`and the reverse link are allocated separate frequencies and are independent
`
`of one another. For code division multiple access (CDMA) technology is the
`
`basis for Interim Standard 95 (IS-95) and can operate in both the 800-MHz and
`
`1900-MHz frequency bands. In CDMA systems, communications between users
`
`5
`
`are conducted through one or more cells/sectors, which are serviced by base
`
`stations. A user of a first mobile communicates with another user on a second
`
`mobile by transmitting voice and/or data on the reverse link to a cell/sector. The
`
`cell/sector receives the data for routing to another cell/sector or a public
`
`switched telephone network (PSTN). If the second user is on a remote station,
`
`10
`
`the data is transmitted on the forward link of the same cell/sector, or a second
`
`cell/sector, to the second remote station. Otherwise, the data is routed through
`
`the PSTN to the second user on the standard phone system.
`
`A mobile communications system can employ connectionless network
`
`services in which the network routes each data packet individually, based on the
`
`15
`
`destination address carried in the packet and knowledge of current network
`
`topology. The packetized nature of the data transmissions from a mobile allows
`
`many users to share a common channel, accessing the channel only when they
`
`have data to send and otherwise leaving it available to other users. The multiple
`
`access nature of the mobile communications system makes it possible to
`
`20
`
`provide substantial coverage to many users simultaneously with the installation
`
`of only one base station in a given sector.
`
`The transfer of digital data packets differs from the transfer of digital
`
`voice information. Full duplex (simultaneous two-way) voice communication
`
`patterns imply that the data, transferred between the base station and a
`
`25
`
`particular mobile station, are real-time and substantially equal in bandwidth. It
`
`4
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`
`
`has been noted that a total delay of 200 msec (about 2 Kbits of digital data for
`
`most speech vocoders) represents intolerable latency within a voice channel.
`
`On the other hand, transfer of digital data packets is typically asymmetrical, with
`
`many more packets being sent from the base station to a particular mobile via a
`
`5
`
`downlink (the forward link}, than from the mobile to the base station via an
`
`uplink (the reverse link).
`
`In high speed data packet transfers, users appear to be tolerant of data
`
`transfer latencies or delays, with
`
`latencies of up to 10 seconds being
`
`encountered in current wireless data systems. While such delays appear to be
`
`1::)10
`
`tolerated by the user, the delays, attributable to relatively low effective data
`
`transfer rates, are undesirable. One proposed solution, known as "CDMA /
`
`HDR" (Code Division Multiple Access / High Data Rate), uses various
`
`techniques to measure channel data transfer rate, to carry out channel control,
`
`and to mitigate and suppress channel interference.
`
`Conventional CDMA systems must handle both voice and data. To
`
`handle voice signals, the delay between the time that information is sent and
`
`the time that the information is received must be kept relatively short. However,
`
`certain communications systems used mostly for handling data packets can
`
`tolerate relatively longer delays or latencies between the time that information is
`
`20
`
`sent and the time that the information is received. Such data handling
`
`communications systems can be referred to as High Data Rate (HOR} systems.
`
`The following description will focus on HOR systems and techniques, but those
`
`skilled in the art would understand that various other mobile communications
`
`systems and techniques for handling high data rates, such as 1xEV-DO, 1xEV-
`
`2s DV, and the like, fall within the scope of the present disclosure.
`
`5
`
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`Page 6 of 540
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`
`
`, .
`
`In general, a High Data Rate (HDR) system is an Internet protocol (IP)
`
`based system that is optimized for transmitting data packets having bursty
`
`characteristics and not sensitive to latencies or delays. In HOR systems, a base
`
`station is dedicated to communicating with only one mobile station at any one
`
`s
`
`time. An HDR system employs particular techniques allowing for high-speed
`
`data transfers. Also, HDR systems are exclusively used for high-speed data
`
`transfers employing the same 1.25MHz of spectrum used in current IS-95
`
`systems.
`
`The forward link in an HOR system is characterized in that the users are
`
`0JIO
`
`\ ,
`
`not distinguished in terms of orthogonal spreading codes, but distinguished in
`
`terms of time slots, whereby one time slot can be 1.67ms (milliseconds). Also,
`
`on the forward link of an HDR system, the mobile (access terminal AT) can
`
`receive data services from about at least 38.4 Kbps to about at most 2.4576
`
`Mbps. The reverse link of an HOR system is similar to the reverse link of an IS-
`
`95 system, and employs a pilot signal to improve performance. Also, traditional
`
`IS-95 power control methods are used for providing data services from about
`
`:::1is
`ttJ
`
`9.6 Kbps to about 153.6 Kbps.
`
`In the HDR system, a base station (a part of the access network AN)
`
`can always transmit signals at its maximum transmission power, as virtually no
`
`20
`
`power control is required because only one user occupies a single channel at a
`
`particular time resulting in practically no interference from other users. Also, in
`
`contrast to an IS-95 system requiring an equal data transfer rate for all users,
`
`an HDR system need not deliver packet data to all users at equal data transfer
`
`rates. Accordingly, users receiving high strength signals can receive services
`
`25
`
`employing high data rates, while users receiving low strength signals can be
`
`6
`
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`Page 7 of 540
`
`
`
`' .
`
`accorded with more time slots so that their unequal (i.e., lower) data rate is
`
`compensated.
`
`In conventional IS-95 systems, because various signals (including pilot
`
`signals) are simultaneously transmitted to all users, interference due to pilot
`
`s
`
`signals and undesirably high power consumption are problematic. However, in
`
`HOR systems, pilot signals can be transmitted at maximum power because the
`
`so-called "burst" pilot signals are employed. Thus, signal strength can be
`
`measured more accurately, error rates can be reduced, and interference
`
`between pilot signals is minimized. Also, as the HOR system is a synchronous
`
`:510
`
`system, pilot signals in adjacent cells are simultaneously transmitted, and
`
`interference from pilot signals in adjacent cells can also be minimized.
`
`Figure 1 shows a portion of a conventional reverse channel structure for
`
`sending transmission data rate increase information from a base station to a
`
`mobile. A base station (not shown) approximates (or measures) a load on the
`
`reverse link, and prepares to send to a mobile (not shown) various messages
`
`indicating whether the reverse link load is large or small. A bit repetition means
`
`10 repeats the bits in the messages to be sent a certain number of times to
`
`improve signal reliability.
`
`Thereafter, a signal point mapper 11 maps the signal from the bit
`
`20
`
`repetition means 1 O by, for example, changing all "O" bits to "+1" and all "1" bits
`
`to "-1" to allow further processing. The resulting signal is combined with a so(cid:173)
`
`called "Walsh cover'' signal and transmitted over the Reverse Activity (RA)
`
`channel to the mobile.
`
`A conventional mobile receives the messages sent by the base station
`
`2s
`
`via the RA channel indicating that the current reverse link load is too large, and
`
`7
`
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`Page 8 of 540
`
`
`
`I
`
`•
`
`the mobile reduces the current packet data rate on the reverse link by one-half
`
`(1/2) so that the load on the reverse link is decreased.
`
`SUMMARY OF THE INVENTION
`
`5
`
`A gist of the present invention involves the recognition by the present
`
`inventors of the drawbacks in the conventional art. In particular, conventional
`
`techniques (e.g., conventional mobile communications systems under the
`
`standards of IS-95, HOR, IMT-2000, etc.) for controlling data transmission rates
`
`between mobiles and a base station do not effectively consider the particular
`
`10
`
`data transmission circumstances and channel conditions of each mobile station.
`
`Conventional HOR systems do not employ effective power control
`
`techniques,
`
`thus
`
`there are difficulties
`
`in providing high-speed data
`
`"
`
`transmissions to those mobiles located far from the base station requiring signal
`
`transmissions at a higher power compared with the signal transmissions for
`
`!~'15 mobiles located in proximity to the base station requiring only low level power.
`
`The conventional HOR system is disadvantageous in that, when the
`
`base station detects the load on the reverse link to be too large and feeds back
`
`this information via a reverse activity (RA) channel, the reverse link packet data
`
`rate is unconditionally reduced by one-half for all users (mobiles), and thus
`
`20
`
`overall data throughput at each base station is undesirably reduced. The
`
`conventional art ignores the situations that individual mobiles have different
`
`requirements and should advantageously be controlled
`
`individually in a
`
`dedicated manner.
`
`Additionally, the conventional HOR system is inefficient because no
`
`25 messages are sent to the mobiles to indicate that their packet data rates should
`
`8
`
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`Page 9 of 540
`
`
`
`.
`
`'
`
`be increased when the reverse link load is small.
`
`Furthermore, the conventional art merely considers the reverse link load.
`
`However, in practical data packet transmission applications, the channel or link
`
`conditions, such as signal interference and transmission power requirements,
`
`5
`
`and other communications environment factors effect data transmissions on the
`
`reverse link.
`
`To address at least the above-identified conventional art problems, the
`
`present invention utilizes information fed back from the forward link for data
`
`packet transmission over the reverse link upon considering the particular data
`
`;910
`::;/'~
`
`transmission circumstances and channel conditions of each mobile station and
`
`accordingly controlling the mobiles in a dedicated manner. By doing so, the data
`
`transmission rate over the reverse link is improved. More specifically, to improve
`
`reverse link data transmission rates, messages informing the mobile station to
`
`adjust (increase, decrease or maintain) its data transmission rate are sent from
`
`the base station in accordance with reverse link load information.
`
`::~15
`
`\;:;:;:;._':
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Figure 1 shows a portion of a conventional reverse channel structure for
`
`sending transmission data rate increase information from a base station to a
`
`20 mobile;
`
`Figure 2 shows a partial structure of a base station according to an
`
`embodiment of the present invention;
`
`Figure 3 shows a partial structure of a mobile according to an
`
`embodiment of the present invention;
`
`25
`
`Figure 4 shows
`
`the details of certain
`
`relative portions of the
`
`9
`
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`
`
`
`determinator 24 in a base station, a portion of which is shown in Figure 2;
`
`Figure 5 is a flow chart showing the main steps involved in transmitting
`
`transmission data rate adjust information to each mobile in a 1xEV-DV or 1xEV(cid:173)
`
`DO system according to the present invention;
`
`s
`
`Figure 6 is a flow diagram of the method for controlling the data
`
`transmission rate in accordance with the present invention;
`
`Figure 7 is a flow diagram of embodiment according to the present
`
`invention;
`
`Figure 8 shows the updating procedure of the BS_RCV according to the
`
`10
`
`present invention;
`
`Figure 9 shows the procedures for generating rate control information
`
`using the BS_RCV values according to the present invention; and
`
`Figure 10 shows an example of how the reverse link data rate is
`
`controlled using the BS_RCV values according to the present invention.
`
`DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
`
`Figure 2 shows a partial structure of a mobile according to an
`
`embodiment of the present invention. A mobile 20 comprises a reception
`
`processor 21, a demodulator 22, a transmission data rate controller 23, and a
`
`20
`
`transmission processor 24. The reception processor 21 processes the signals
`
`received from a base station via a reception antenna A 1. The demodulator 22
`
`demodulates the signals processed by the reception processor 21. The
`
`transmission data rate controller 23 controls the transmission data rate based
`
`on the transmission data rate adjustment information in the signals processed
`
`2s
`
`by the demodulator 22. The transmission processor 24 transmits signals via a
`
`10
`
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`Page 11 of 540
`
`
`
`transmission antenna A2 to the base station in accordance with the control of
`
`the transmission data rate controller 23.
`
`According to Figure 2, the mobile according to an embodiment of the
`
`present invention can comprise a determining means which determines a
`
`s
`
`transmission energy level required for transmitting to a base station. Here, the
`
`determining means can comprise the transmission data rate controller 23 and
`
`the transmission processor 24, in their entirety or portions thereof.
`
`Also, the mobile according to an embodiment of the present invention
`
`can comprise an adjusting means operatively connected with the determining
`
`10 means, which adjusts a data transmission rate based upon a comparison result
`
`received from the base station in a dedicated manner via a common channel,
`
`the comparison result being obtained by comparing the transmission energy
`
`"
`
`level and an interference level of signals sent to the base station by the mobile
`
`stations. Here, the adjusting means can comprise the transmission data rate
`
`i'~l5
`
`controller 23, and the transmission processor 24, in their entirety or portions
`
`thereof.
`
`Furthermore, the mobile according to an embodiment of the present
`
`invention can comprise a transceiver operatively connected with the adjusting
`
`means, which transmits packet data on the reverse link in accordance with the
`
`20
`
`adjusted data transmission rate. Here, the transceiver can comprise the
`
`reception processor 21, the demodulator 22, the transmission processor 24,
`
`and antennae A 1 and A2, in their entirety or portions thereof.
`
`Figure 3 shows a partial structure of a base station according to an
`
`embodiment of the present invention. A base station 30 comprises a reception
`
`25
`
`processor 31, an
`
`interference
`
`level detector 32, a comparator 33, a
`
`11
`
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`
`
`
`determinator 34, and a transmission processor 35. The reception processor
`
`31 processes (e.g., demodulates) the signals received from mobiles (not
`
`shown) via a reception antenna A3. The interference level detector 32 receives
`
`the processed signals from the reception processor 31 for estimating and/or
`
`s
`
`detecting a level of signal interference related to the processed signals.
`
`As understood by those skilled in the art, there are various types of
`
`signal
`
`interference between mobiles and base stations
`
`in mobile
`
`communications. For example, in the case of the reverse link, an important
`
`parameter is the rise in the level of the total amount of noise over the level of
`
`10
`
`the thermal noise at a base station. This parameter is referred to as the "rise
`
`over thermal" (ROT). The rise over thermal (ROT) corresponds to the loading of
`
`the reverse link.
`
`Typically, a communications system attempts to maintain the ROT near
`
`a predetermined value. If the ROT is too great, the range of the cell is reduced
`
`15
`
`and the reverse link is less stable. A large ROT can also cause small changes
`
`in instantaneous loading that result in large excursions in the output power of
`
`the mobile station. When the ROT is considered to be too high (e.g., above a
`
`desired threshold level), the data transmission rate can be decreased or even
`
`interrupted until the reverse link is stabilized. In contrast, a low ROT can
`
`20
`
`indicate that the reverse link is not heavily loaded, thus potentially wasting
`
`available capacity. Thus, if the ROT is considered to be too low (e.g., below a
`
`desired threshold level), the data transmission rate can be advantageously
`
`increased. It will be understood by those skilled in the art that methods other
`
`than measuring the ROT can be used in determining the loading of the reverse
`
`25
`
`link.
`
`12
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`. .
`
`After the interference level detector 32 detects the signal interference,
`
`the comparator 33 compares the detected level of signal interference with a
`
`threshold value in order to estimate (determine) the load on the reverse link.
`
`The determinator 34 determines a transmission data rate adjust information
`
`5
`
`(e.g.,
`
`increase, decrease or maintain) based on
`
`the reverse
`
`link load
`
`determined by the comparator 33, and determines a position of each mobile
`
`(i.e., a physical location of each mobile in the cell/sector served by the base
`
`station) based on the rate control bit (RCB) position in the channel slots. The
`
`RCB position in the channel slots allows mobiles to be discriminated from one
`
`10
`
`another.
`
`The transmission processor 35 modulates a transmission signal for
`
`sending the transmission data rate adjust information from the determinator 34
`
`;,
`
`to each mobile, and transmits signals to each mobile via a transmission antenna
`
`A4. Here, the signals including the RCB information are transmitted to each
`
`15 mobile via a common channel. The common channel can be a known channel
`
`already used in conventional mobile communications. For example, the so(cid:173)
`
`called "RA channel" can be employed in the present invention for transmitting
`
`signals and RCB information to each mobile. Alternatively, the signals including
`
`the RCB information are transmitted to each mobile via a newly established
`
`20
`
`channel (Common Reverse Packet Data Control Channel - CRPDCCH), not
`
`currently existing
`
`in conventional mobile communications systems and
`
`techniques. Here, various conventional techniques may be employed
`
`in
`
`establishing a new type of channel, with a feature of the present invention being
`
`the use of rate control bit (RCB) in the frames (16 slots) transmitted to the
`
`25 mobiles.
`
`13
`
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`
`
`According to Figure 3, a base station according to an embodiment of
`
`the present invention can comprise a determining means, which determines an
`
`interference level of signals received from the mobile stations, and determines a
`
`transmission energy
`
`level
`
`required
`
`for each mobile station. Here,
`
`the
`
`5
`
`determining means can comprise the interference level detector 32 and the
`
`comparator 33, in their entirety or portions thereof.
`
`Also, a base station according to an embodiment of the present
`
`invention can comprise a comparing means operatively connected with the
`
`determining means, which compares
`
`the
`
`interference
`
`level with·
`
`the
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`10
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`transmission energy level to obtain a comparison result for each mobile station.
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`Here, the comparing means can comprise the comparator 33 and determinator
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`34, in their entirety or portions thereof.
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`Additionally, a base station according to an embodiment of the present
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`invention can comprise a transceiver operatively connected with the comparing
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`15 means, which sends the comparison result via a common channel on a forward
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`link to each mobile station in a dedicated manner in accordance with the
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`comparing, and receives packet data on the reverse link in response to the
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`sending. Here,
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`the transceiver can comprise a reception processor 31,
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`transmission processor 35, and antennae A3 and A4, in their entirety or portions
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`20
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`thereof.
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`Accordingly, by using the general features of a mobile shown in Figure 2
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`and the features of a base station shown in Figure 3, data packets can be
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`transmitted between the mobile and base station in accordance with the present
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`invention. A more detailed description and explanation of the structural aspects
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`25
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`and methods involved in the present invention are as follows.
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`14
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`Ex. 1007 - Sierra Wireless, Inc.
`Sierra Wireless, Inc., et al. v. Sisvel S.P.A., IPR2021-01141
`Page 15 of 540
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`Figure 4 shows the details of certain relative portions of the
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`determinator 34 in the base station shown in Figure 2. The determinator 34
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`comprises a plurality of repeaters 41, a plurality of signal point mappers 42, a
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`plurality of channel gain units 43, a pair of multiplexors 44, and a long code
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`s
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`processor 45 having a long code generator 46, a decimator 47, and a relative
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`offset calculator 48.
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`In the present invention, mobiles can be controlled via the so-called "!(cid:173)
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`channel" or "Q-channel" or both channels. Here, "I" refers to "in-phase" and "Q"
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`refers to "quadrature," which are known terms in the art of digital signal
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`10 modulation,
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`in particular vector modulation. Vector modulation (of which
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`quadrature amplitude modulation (QAM) is a popular type) is at the heart of
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`most digital wireless (mobile) communication systems. QAM packs multiple
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`data bits into single symbols, each of which modulates the carrier's amplitude
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`and phase.
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`15
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`Of the reverse link load determined by the comparator 33, rate-control
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`bits (e.g., RCBs) for each user (mobiles) 0 through N are sent to the
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`determinator 34. Here, N denotes the number of users being controlled using
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`the I-channel and/or Q-channel, which are also referred to as an "I-Arm" and a
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`"Q-Arm." Based upon the RCBs transmitted to the mobiles during one data
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`20
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`frame (the frame having 16 slots), the base station can control a plurality of
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`mobiles using the I-channel, the Q-channel, or both.
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`The repeaters 41 of the determinator 34 receive the RCB data
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`(including rate-control bits) related to a plurality of users (mobiles) 0 through N,
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`and respectively processes these data for ultimately generating I-signals (X 1 )
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`25
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`and/or Q-signals (X0 }.
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`15
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`Ex. 1007 - Sierra Wireless, Inc.
`Sierra Wireless, Inc., et al. v. Sisvel S.P.A., IPR2021-01141
`Page 16 of 540
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`. .
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`For example, 12, 24, 48, 96, 192 or 384 mobiles can be controlled by
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`the base station according to the present invention. If only the I-channel or the
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`a-channel is used, 12, 24, 48, 96 or 192 mobiles can be controlled.
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`If both the
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`I-channel and a-channel are used, 24, 48, 96, 192 or 384 mobiles can be
`
`s
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`controlled. When either the I-channel or the a-channel is used to control 12
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`mobiles, the repeater 41 repeats the bits in the messages to be sent 16 times to
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`improve signal reliability. In this manner, for respectively controlling 24, 48, or 96
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`mobiles, 8, 4, or 2 repetitions are performed, respectively. For controlling 192
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`mobiles, no repetitions are made. Namely, instruction signals are sent to the
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`10 mobiles without performing any bit repetitions.
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`In a similar manner, when both
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`the I-channel and the a-channel are used, for respectively controlling 24, 48, 96
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`or 192 mobiles, 16, 8, 4, or 2 repetitions are performed. For controlling 384
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`mobiles, instruction signals are sent to the mobiles without performing any bit
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`repetitions.
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`15
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`Although a particular number of mobiles capable of being controlled
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`have been exemplified above based upon there being 16 slots in a frame to be
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`transmitted, those skilled in the art would understand that other specific number
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`of mobiles could also be handled according to the present invention depending
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`upon the particular frame size and number of slots therein.
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`20
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`Then, the signal point mappers 42 map the signals received from the
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`repeaters 41 by, for example, changing all "O" bits to "+1", all "1" bits to "-1", and
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`no symbol bits to "O" to allow further processing.
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`Here, the signal point mapping techniques can generally be performed
`
`in a variety of ways, as understood by those skilled in the art. However, a
`
`25
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`preferred method in signal point mapping according to the present invention
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`16
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`Ex. 1007 - Sierra Wireless, Inc.
`Sierra Wireless, Inc., et al. v. Sisvel S.P.A., IPR2021-01141
`Page 17 of 540
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`involves a particular technique of processing the RCBs. Namely, based upon
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`the transmission data rate adjust information, if the current transmission data
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`rate is to be increased, the base station sets the RCB to "INCREASE" and if the
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`current transmission data rate is to be decreased, the base station sets the
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`5 RCB to "DECREASE" Also, if current transmission data rate is to be maintained,
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`no RCB information is transmitted by the base station to the mobile.
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`Also, the number of slots used for processing a symbol depends upon
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`the number of users N. For example, if N = 12, 1 symbol per 1 slot is processed.
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`Also, for N = 24, 48, 96 or 192, 1 symbol / 2 slots, 1 symbol / 4 slots, 1 symbol /
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`10
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`8 slots, and 1 symbol / 16 slots are processed, respectively, as indicated in
`
`Figure 4.
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`Thereafter, the channel gain units 43 further process each signal
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`received from the signal point mappers 42, respectively. Namely, channel gain
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`amplification
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`is performed and
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`the processed signals are sent to
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`the
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`15 multiplexers (MUX) 44, the features of which are explained further below. Here,
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`the channel gain amplifying techniques can generally be performed in a variety
`
`of ways, as understood by those skilled in the art.
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`Additionally, the RCB data related to 1-Q signal generation includes
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`initial offset values (0 to N-1) assigned to each user (mobile) and which
`
`20
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`determine the position of each mobile (based on the RCB position in the
`
`channel slots). Here, the initial offset values are determined (or generated)
`
`during a so-called "negotiation" process between mobiles and the base station.
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`Of the initial offset values, "O" indicates the first position among the channel
`
`slots, while "N-1" indicates the last position.
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`25
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`The determinator 34 also includes a long code processor 45 comprising
`
`17