Alleviating mobile device overload conditions in a mobile communication system

[0001] The present invention relates to mobile communication, and in particular to methods and devices intended for use in a mobile device for preventing or reducing an overload condition in a mobile communication system.

[0002] Future E-UTRAN (Evolved-Universal Terrestrial Radio Access NetWork) access technology in LTE (Long Term Evoiution) systems, as defined in 3GPP TR 36.201, "Evotved Universal Terrestrial Radio Access (E-UTRA) ); Long Term Evolution (LTE) physicaf layer; General description "will be adapted to work in a very wide range of operating bands (e.g. from 1.4 MHz to 20 MHz), as well as carrier frequencies. In addition, E-UTRAN systems will be adapted to work over a wide range of distances, from microcells (i.e. cells served by low power base stations that cover a limited area, such as a shopping center or other public building), up to macrocells with a range of 100 km. To handle different radio conditions that may be used in different applications, multiple downlink access (i.e. the communication link from the base station to the user equipment - "UE" (ang. user equipment) is obtained in the technology of access with orthogonal frequency multiplication (OFDMA), as it is a radio access technology that can adapt very well to various propagation conditions. In OFDMA, the available data stream is divided into a number of narrowband subcarriers that are transmitted in parallel. Since each subcarrier is narrowband, it only experiences flat decay. This makes demodulation of each subcarrier in the receiver very easy.

[0003] Data rates above 300 Mb / s will be supported for the widest bands, and such data rates will be possible due to the use of MIMO (Multipie-Input-Muitiple Output) in the downlink.

[0004] The possibility of higher data rates in combination with other requirements of ever greater functionality in increasingly smaller mobile devices increases the likelihood of high power consumption in these devices, which in turn creates the possibility of even more likely problems of overheating. Overheating increases the risk of circuit damage in a mobile device. There is therefore a need to reduce the risk of overheating of the mobile device.

[0005] Even if the circuit has not yet reached temperature levels causing damage, its proper operation may be disturbed when approaching such temperatures. The temperature level at which this occurs depends on the circuit and bus clock speed as well as the battery voltage. There is therefore a complex relationship between temperature, battery voltage and clock speed.

[0006] There are other problems associated with higher data rates in systems

-2mobile communication using modems. The high peak data rate allows the system to take advantage of the increased system capacity by appropriately scheduling different users. This means that there will be a big difference between the peak and average data rates for individual users. In some cases, it may by the user's device all data received on the downlink (i.e. communication link from the serving base station to the user's device).

[0007] With respect to a problem with a user equipment that is unable to support a peak downlink data rate, conventional solutions include scheduling only specific peak data rates relative to the user equipment. Alternatively, systems can completely rely on data retransmission in cases where the user's device was unable to process all the data received (e.g. in the event of a buffer overflow, the computational power for signal processing is exceeded, or other factors limiting the ability to process instantaneous data rates by the user's device). However, reliance on retransmissions after an overload occurs can increase the loss of synchronization of processes occurring in the user's device in real time, which in turn causes the risk of the user's device losing synchronization and breaking the existing connection.

[0008] Accordingly, there are a number of user device overload conditions (e.g., thermal overload, buffer overflow, computational power overload for signal processing) associated with higher data rates of modem mobile communication systems. Therefore, there is a need to provide methods and devices that solve these problems. Document EP 1 513 356 A2 is considered to be the closest prior art on which the preamble of independent claims is based. This document discloses a radio communication system and radio communication device. In the mobile terminal the reception quality estimation module measures the reception quality, and at least one of the data buffer monitoring module and the transmission power monitoring module measures the data transmission capacity. Based on the measured reception quality and data transmission capacity, the terminal determines the appropriate transmission mode for use and reports it to the base station. The base station determines the transmission mode which, according to the notified transmission mode, is to be practically used and notifies the mobile terminal about it. The base station transmits data according to the designated transmission mode, while the mobile terminal receives data according to the notification about the transmission mode. Thus, the radio communication system determines the transmission mode taking into account not only the quality of the reception, but also the lack of data transmission capacity of the terminal.

SUMMARY OF THE INVENTION [0009] It should be emphasized that the terms "comprises" and "containing" used in this specification mean the presence of the indicated elements, the whole, the stages or components; but the use of these terms does not exclude the presence or addition of one or more other elements, the whole, stages, components or groups thereof.

[0010] According to one aspect of the present invention, the above and other objects are achieved in methods and devices that control the operation of a user equipment in a mobile communication system.

-3 Operation ίο involves controlling a receiver of a user equipment for receiving one or more data blocks via a channel. In response to the detected overload condition of the user equipment, the channel quality indicator (CQI) is reported to the serving base station, where the reported CQI value is a channel quality that is lower than the actual channel quality. The user equipment is then used in a manner appropriate to the CQI value reported.

[0011] The operation of the user equipment includes sending negative acknowledgment signals (NAK) to the serving base station at a speed corresponding to operation on a channel of a quality that corresponds to the reported CQł value, including sending one or more NAK signals in response to an acceptable receiving one or more data blocks. The sending of NAK signals to the serving base station at a speed corresponding to operation in a channel of a quality that corresponds to the reported CQI value is also carried out in such a way that these NAK signals are distributed in time in a manner emulating the distribution of NAK signals corresponding to a channel of quality that corresponds reported CQI value. For example, the time distribution of NAK signals can be random or pseudo-random.

[0012] In another aspect of certain embodiments of the invention, the reported CQI value is selected by determining which of a number of possible CQI values ​​will cause a user device to retain as much functionality as possible while reducing or preventing an overload condition of that user device.

[0013] In yet another aspect of certain embodiments of the invention, the overload condition of the user equipment is an overheating condition.

[0014] Among other possibilities, the overload condition may be a limitation of the processing capabilities of the user equipment. This limitation may be, for example, the bottleneck of the receiving buffer, sending buffer, signal processing; or the inability to process data blocks received at a temporary downlink rate. As used herein, the term "bottleneck" means part of a path with a lower bandwidth than the other parts constituting this path, [0015] In another aspect of certain embodiments of the invention, the overload condition may be a warning that actual overload condition will occur when the user equipment is continued operating in the current operating mode. In these examples, the user equipment is also adapted to take action to avoid the actual occurrence of an overload condition.

BRIEF DESCRIPTION OF THE DRAWINGS [0016] The objectives and advantages of the present invention will become apparent upon reading the following detailed description in connection with the figures of the drawings, of which:

FIG. 1 is a flowchart of exemplary steps / processes performed by a suitably adapted logic in a user equipment in accordance with embodiments of the present invention.

FIG. 2 is a high-level block diagram of an exemplary user device adapted to perform the functions described above.

-4FIG, 3 is a flowchart of exemplary steps / processes performed by a suitably adapted logic in a user equipment in accordance with embodiments of the present invention that indirectly cause a serving node to lower a data throughput rate over a downlink.

FIG. 4 is a block diagram of an exemplary user device that includes components that are particularly adapted to reduce or prevent an overheating condition in a user device.

FIG. 5 is a block diagram of an alternative embodiment of a user equipment that includes elements that are particularly adapted to reduce or prevent an overheating condition in a user equipment.

FIG. 6 is a flowchart of a method with exemplary steps / processes performed by a suitably adapted logic in a user equipment in accordance with alternative embodiments of the present invention.

FIG. 7 is a block diagram of an exemplary user device supported by an eNode-B node as well as an exemplary signaling from a user device indicating an overload condition.

FIG. 8 is a block diagram of an exemplary user equipment that includes elements that are particularly adapted to reduce or prevent resource overload in a user equipment.

DETAILED DESCRIPTION [0017] Particular elements of the present invention will now be described with reference to the drawings, in which similar parts are designated by the same reference numerals.

[0018] Various aspects of the present invention will now be described in more detail with respect to a number of embodiments of the invention. To facilitate understanding of the invention, numerous aspects of the invention are described by a sequence of actions envisaged to be performed by components of a computer system or other equipment adapted to execute programmed commands. It should be noted that in each of these embodiments, individual operations could be performed by specialized circuits (e.g., discrete logic gates connected to perform a specialized function), through program commands executed by one or more processors, or by a combination thereof. In addition, it may be further contemplated that the present invention may be implemented in its entirety in any form of computer-readable medium, such as a semiconductor memory, magnetic disk, or optical disk containing a corresponding set of computer commands that would make the processor perform the techniques described herein. Thus, individual aspects of the invention may be embodied in many different forms, and all such forms are considered to fall within the scope of the present invention. For each of these particular aspects of the invention, each embodiment of the invention may be referred to herein as a "logic configured to" perform the described operation, "adapted logic" to perform the described operation, or alternatively as a "logic that performs the described operation.

[0019] To facilitate the description of individual aspects of embodiments of the present invention, these

- specific examples are described in the context of the LTE system. For example, the network access point from which the user obtains the service is called "eNode-B". However, the use of LTE system terminology is not intended to limit the scope of the present invention. For example, references to "eNode-B" made in the description, as well as in the claims, should be understood to include not only eNode-B nodes from the LTE system, but also their equivalents in other systems (e.g. node B or other base station). [0020] In one aspect of embodiments of the present invention, an overload condition of the user equipment is detected, and one or more actions are taken in response to it in the user equipment to directly or indirectly eliminate the cause of the overload condition of the user equipment. These and other aspects are described in more detail below.

[0021] FIG. 1 is a block diagram of exemplary steps / processes performed by a suitably adapted logic 100 in a user equipment according to embodiments of the display. This user equipment is in the mode of connecting to the serving network (step 101). As a result, uplink and downlink data and control information are exchanged between the user equipment and the eNode-B node of the network. This exchange takes place according to the protocol of the cellular system, such as, without imposing LTE, e-HSPA or WiMax.

[0022] At some point, an overload condition is detected in the user equipment ("YES" path from decision block 103). The overload condition may be e.g. overheating condition. Alternatively, the overload condition may be the inability of the user equipment to process data at the rate at which it is received. In any of these cases, the overload condition may represent a condition in the user's device or alternatively may be a warning that an actual overload condition will occur if the user's device continues to operate in the current operating mode.

[0023] In response to the detected overload condition, the user equipment changes its operation in a way that results in reducing or preventing the occurrence of an overload condition. For example, a user device may respond to an overload condition by taking one or more steps that directly or indirectly result in a reduction in power consumption by that user device. In another embodiment, the user equipment may respond to too high data rates by taking one or more steps that cause the serving node to reduce the downlink data rate.

[0024] FIG. 2 is a high level block diagram of an example user device 200 adapted to perform the functions described above. In this example, the user equipment 200 includes first and second antennas 201, 203, each of which is used for both transmitting and receiving radio signals. Having more than one antenna enables the user device 200 to work in the Mi MO (ang. multiple input multiple output - a system with multiple transmitting and receiving antennas) known from the state of the art. However, this is not essential to the invention, and other embodiments could include only one antenna or more than two antennas. The number of antennas is also not a factor in the functionality of the user equipment, and it does not limit the scope of the invention. For example, with a view to reducing costs (e.g. need to use additional power amplifiers) often the user's device is designed to work with asymmetrical receiving / transmitting paths (e.g. two receiving paths and only one transmission path).

The transceiver circuits 205 in the user equipment 200 include a receive path and a transmit path. The receiving path includes a front-end receiver 207 that receives radio signals from the first and second antennas 201, 203 and produces a signal in the baseband that is supplied to the decoder 209. The decoder 209 processes the received signal in the baseband and generates data transmitted by the radio signal from it. . This data is provided to the application in the user's device 200 for further processing. The nature of the further processing falls outside the scope of the present invention.

[0026] The transmission path comprises an encoder 211 and a head transmitter 213. The operation of the transmission path is essentially the opposite of the receiving path. Encoder 211 receives data from an application running on user equipment 200 and formats this data in a manner that makes it suitable for transmission (e.g., using correction coding and interleaving). The encoded data, which falls within the baseband, is delivered to the head transmitter 213, which converts this baseband signal into a modulated radio frequency signal. The modulated radio frequency power is set to the desired level and applied to the first and second antennas 201, 203 for transmission. (In embodiments of the invention using only one transmission path, the output signal is only fed to one of the first and second antennas 201, 203.) Although not illustrated in this figure, it should be understood that the user equipment 200 includes circuits to ensure that the transmitted signals they do not appear on the front terminals of the 207 front receiver.

[0027] The individual blocks in the transceiver 205 operate in accordance with the control signals that are produced by the control module 215. To ensure the operation of the user equipment described with reference to FIG. 1, the user equipment 200 also has an overload detection module 217 that monitors one or more states in the transceiver 205 and determines whether these states constitute an overload condition. The results of this determination are provided to the control module 215, which can then take appropriate action. For example, as described above, if an overheating condition is detected, the control module 215 may take one or more steps to alleviate this condition, e.g. limiting the maximum transmit power or reducing the speed at which data is to be transmitted. These actions are described in more detail in discussion below.

[0028] Let's consider the overheating state in the user equipment first. Changing the user device operating mode to eliminate overheating may include any of the following actions or a combination thereof. Overheating can be reacted by lowering the level of power consumption in the user's device, which can be achieved in various ways. One technique involves reducing the amount of power consumed by the transmitting portion of a user's device circuits. For example, the maximum allowable transmit power (usually the maximum transmit power of 24 dBm in an LTE or e-HSPA system) by the user device transmitter may be limited, reducing the maximum allowable transmit power usually results in significantly lower power consumption in the transmitting portion, but this in turn reduces the maximum possible uplink data transmission rate. In some embodiments of the invention, it is preferable to inform the eNode-B that the user equipment will use a reduced transmit power level so that the network can take this into account when scheduling uplink allocations (i.e., because reduced transmit power means that data rates will be reduced ).

[0029] another way to reduce power consumption and thus reduce the temperature in the device

-Ί user, it is off one or more transmitters, as long as the user's device contains more than one transmitter. This leaves only a certain subset of the transmitters enabled on the user's device, which are used to maintain a connection to the network.

[0030] By reducing the power consumed by the user device's receiving circuits, the user device's temperature can also be reduced. A direct way to do this is to turn off one or more receiving paths, leaving only a certain subset of receivers powered up to maintain a connection to the network.

[0031] Another way to achieve this is to reduce the clock cycle frequency of the decoding process. Because the baseband power consumption is proportional to the clock cycle frequency, a lower power consumption level will be obtained. However, this also results in a lower level of maximum downlink data capacity. [0032] Yet another technique for limiting the power consumed by a user equipment and thus reducing the temperature in a user equipment is to limit the downlink data rate. Because much of the power consumed for the baseband is proportional to the data rate, the reduced data rate results in less power consumption. Since the serving node is responsible for selecting the downlink data rate, it is necessary for the user equipment to take some action that will cause the serving node to perform the desired data rate adjustments.

[0033] In certain example embodiments of this invention, this can be achieved by directly signaling to the serving node the need for a lower data rate. However, usually acceptable signaling is set by published standards for a given type of system. In the event that the applicable standard does not provide a mechanism in which the user equipment could explicitly request a lower downlink speed, it is still possible for the user equipment to achieve this effect. FIG. 3 is a block diagram of exemplary steps / processes performed by a suitably adapted logic 300 in a user equipment according to embodiments of the present invention, which indirectly causes the serving node to reduce the downlink data rate. In one aspect of this embodiment of the invention, the user equipment sends a channel quality indicator (CQI) request to the eNode-B (or equivalent) node channel quality indicator), whereby the reported value (CGIreported) is intentionally equated with a value that indicates a lower channel quality than the current one (i.e. the true channel quality value should be equal to CGI_ACTual) (step 301). The theoretical foundations for this action are as follows: CQI is usually derived from the instantaneous signal-to-interference ratio (SIR) for the received signal. CGI value_actual is associated with the highest possible data throughput for the SIR value of the received signal. A lower CQi value indicates to the eNode-B that the SIR ratio is lower. As a result, the eNode-B will respond by increasing the level of encoding used for broadcast information. The more encoding used, the lower the downstream bandwidth.

[0034] In certain example embodiments of this invention, this may be the only thing required: When the CQI value is reduced, the network will typically respond by introducing more encoding into the transmitted bits, thereby reducing downlink bandwidth.

[0035] In contrast, in other embodiments of the invention, the network checks the correctness of the reported CQI value. For example, the worse the channel is, the more errors can be expected when sending data blocks from the serving node to the user's device at a given code efficiency. At the serving node, this can be measured e.g. by measuring the number of negative signals (NAK) that are received over a given time period. As is well known, the NAK signal is sent back by the receiver of the data block to the server to indicate that this block has been received with errors and should be sent again. Accordingly, the serving node may measure the frequency of receiving NAK signals from the user equipment and may compare it with the CQI expected value reported by the user equipment. For example, the typical block error rate that the system would expect to achieve is 10%. But if the network reduces the downlink data rate in response to its "belief" that the COIreported value accurately represents channel quality that is actually higher than reported, the current frequency of NAK signals should become lower than expected. If the frequency of NAK signals is less than the expected COIreporteo value. then the network could assume that the COIreported value is inaccurate and keep the current data rate down the link (or return to the previous one).

[0036] To prevent this from happening, the user equipment should operate in a manner that matches the reported CGI value (step 303). For example, the user equipment should send NAK signals to the serving node at a frequency that corresponds to the channel whose quality corresponds to the reported CQI value. With high probability this translates into sending one or more NAK signals for data blocks whose reception was possible (i.e. received without errors or received with errors whose correction was possible).

[0037] In some embodiments, even this may not be enough to "convince" the network that the channel between the serving node and the user equipment is really as low quality as reported by the user equipment. In these cases, additional steps are required. For example, for a given channel quality, the network can expect not only that in a given time interval a certain number of NAK signals will be received, but also that these NAK signals will be distributed in that interval in the expected manner. Accordingly, the user equipment in such cases should not only send NAK signals at a frequency corresponding to the reported CQi value, but should also ensure that the distribution of these NAK signals over time will correspond to the expected distribution for the reported CQL value. For example, such NAK signal distribution may be random or pseudorandom.

[0038] Since reporting a lower CQI value will cause the network to lower the downlink data rate, the user equipment is confronted with the question exactly what value to report. In some embodiments, it can handle this by selecting a value from the given set of values ​​that is slightly lower than the actual CQI value. Alternatively, the user equipment may always report the lowest possible CQI value when it wants to reduce the downlink data rate. In contrast, in a number of embodiments of the invention, it is preferred to select a CQI value by determining which of a number of possible CQI values ​​will cause the user equipment to retain as much functionality as possible while reducing the overload condition of the user equipment.

[0039] The following factors should be taken into account when choosing the appropriate CQI for reporting: W

-9 embodiments (e.g. dia LTE and HSPA) each increase in CQI value corresponds to an increase of 1 dB. Report CQł = 0 usually means the worst channel quality, so the eNode-B can respond to such a request by eliminating normal data traffic to the user's device. (However, control signaling should still be sent to allow improvement, e.g. by transferring the connection to another eNode-B node.) Reducing the CGI value by a set number of steps (e.g. by reporting a CQI value that is lower than CGIactual by a size in the range of 6 to 12 that would be 6-12 dB below the stated SIR ratio) the bandwidth will be reduced by 6-12 dB (factor 4-16), significantly reducing the risk an overload condition has occurred in the user's device. To illustrate this with an example, let's assume that a user device is overloaded at CQI = 28 and a downstream data rate of 25 Mb / s. The reduction by a factor of 4-8 still allows a data transmission rate of 2-6 Mb / s, which is a reasonably good service for the user and far exceeds the requirements of RRC (Radio Resource Control) signaling (which are up to about 100 kb / s) ).

[0040] FIG. 4 is a block diagram of an exemplary user equipment 400 that indicates elements that are particularly adapted to reduce or prevent an overheating condition in user equipment 400. The user equipment 400 includes a number of the same elements as those previously described with reference to FIG. 2, Therefore, these elements that are common to both of these figures need not be described again. User device 400 includes a temperature measuring module 401 that generates a T signal_t which represents the / th estimation (where / is an integer) of the temperature at the user equipment 400. This temperature signal is provided to the control module 403.

[0041] The control module 403 compares the temperature estimate with a threshold value. This comparison indicates whether or not the user device 400 is in an overheating state (or in some embodiments). In response to the detected overheating condition, the control module 403 generates control signals to cause any or a number of the overheating reduction measures described above (e.g. limiting transmit power, decreasing code efficiency, etc.).

[0042] FIG. 5 is a block diagram of an alternative embodiment of a user equipment 500 that includes elements that are particularly adapted to reduce or prevent an overheating condition in the user equipment 500. The user equipment 500 includes a number of the same elements as those described above with reference to FIG. 4, Therefore, the elements that are common to both of these figures do not need to be described again. The user equipment 500 differs from the user equipment 400 in that the threshold value with which the temperature estimate is compared is not fixed, but instead this is determined dynamically. To achieve this functionality, user device 500 includes a module that sets a threshold value of 501. In the illustrated example, the module setting the threshold 501 determined what temperature level would be the state of overheating (or would indicate that the user device 500 would overheat), which is based on the current battery voltage, the level of filling data in the buffer and the clock frequency of the processing modules and / or buses on user device 500. A strategy is adopted in which a higher threshold value for transient effects (e.g. transmission pulses) and / or when the temperature rise is predictable and slow (e.g. for

- 10 current battery power consumption). In contrast, to ensure that action is taken before overheating becomes a serious problem, a lower threshold value is used when the heating phenomenon is less transient (e.g. predictable moderate or fast heating due to a long process) and / or when the temperature rise is quite unpredictable (e.g. at high transfer rates and / or clock frequencies).

[0043] More specifically, thermal problems can arise from a variety of sources, each of which involves a certain level of predictability and rate of temperature rise. These characteristics can give hints as to what value would be the appropriate threshold. It is desirable to be able to take action before the temperature becomes high enough to cause damage or otherwise adversely affect the operation of the device. Thus, situations associated with very rapid heating require a low threshold so that corrective action can be taken as early as possible. In contrast, situations that cause slow heating may be associated with a high threshold value because a quick response is not required - in these circumstances you can allow your device to continue to run for a longer period of time with higher efficiency before it is reduced in some way to reduce power consumption (and thus reduce the temperature). If the nature of this heating is unpredictable, prudence requires a lower threshold so that corrective action can be taken sooner rather than later to avoid any possible damage.

[0044] Whether the set of heating causes is long-lasting or transient can also be a factor in determining the appropriate threshold. For example, if it is known that these circumstances are transient, a high threshold may be acceptable even if rapid heating is expected because this heating cannot last long enough to cause damage. [0045] Some examples will illustrate various aspects. Consider a short series of high transmit power at the output of a power amplifier at low data rates (as indicated, for example, by the clock frequency). The heating will be fast, but it is known that this is only a temporary situation, so in such circumstances, to avoid unnecessary action, a higher temperature threshold will be appropriate. Other thermal problems arise in conditions that persist for a long time, e.g. at very high data rates. (High data rates can cause overheating because high data rates require a high clock frequency, which in turn causes more power consumption than at lower clock frequencies.) For those overheating problems that occur slowly over time, a lower one is suitable threshold value.

[0046] It is preferable to monitor the battery level because the lower the voltage, the lower the power consumption of the integrated circuit (the power is proportional to the square of the supply voltage). Therefore, the lower the battery level, the longer the circuits will heat up, and therefore the temperature threshold may be set to a higher value.

[0047] Monitoring the level of data in the buffer is beneficial because information indicating that the data buffer is full indicates that there is a high risk that the overheating situation (due to high processing load) will persist for some time and the low indication The use of data buffer shows that the processing load (and therefore temperature) probably

- 11 will drop shortly (i.e. when the buffer is empty). The previous situation requires a lower threshold if heating occurs quickly and the latter requires a higher threshold to avoid taking unnecessary action in response to a situation that will soon clear itself.

[0048] The threshold value determined by the module defining the threshold value 501 is then provided to the control module 503.

[0049] The control module 503 then compares the temperature estimate with the dynamically determined threshold value. As in the example described earlier, the comparison indicates whether the user device 500 is in an overheat state or is approaching it (in some embodiments of the display). In response to the detected overheat state, the control module 503 generates dfa control signals causing any or some the number of overheating reduction measures described above (e.g., reduction of transmit power, reduction of code efficiency, etc.).

[0050] The discussion will now relate to embodiments of the invention in which the overload condition is the inability of the user equipment to handle data at the rate at which it is provided on the downlink. As mentioned earlier, this state can be attributed to a number of different cases, including but not limited to, a receive buffer overflow or downlink data rate that exceeds the computing power for processing a user's device signal.

[0051] FIG. 6 is a block diagram of exemplary steps / processes performed by a suitably adapted logic 600 in a user equipment in accordance with embodiments of the present invention. This user equipment operates in a mode of connecting to a serving network (step 601). As a result, uplink and downlink data and control information are exchanged between this user device and the eNode-B (or equivalent). This exchange takes place in accordance with a cellular system protocol such as, but not limited to, LTE, e-HSPA or WiMax. [0052] During a network connection, the user equipment monitors the use of one or more (depending on the specific embodiment of the invention) resources of the user equipment (step 603). These resources include, but are not limited to the use of receive buffer and signal processing.

[0053] Until resource overload is detected (path "NO" from decision block 605), operation proceeds as described.

In contrast, if resource congestion is detected (path "YES" from decision block 605), the user equipment refers to a logic adapted to limit the data transmission rate in the user equipment and network infrastructure (step 607). This includes notifying the network that it should reduce peak data rates, either for a limited period of time or for indefinite notice to the opposite, depending on the embodiment of the invention. [0055] In some other examples, the user equipment signals to the network a notification of the limited processing capabilities of this user equipment. This signaling can be in the form of a short message that indicates, e.g., the reason for this restriction, the status of the receive buffer, the current maximum data rate possible, the duration of this restriction and other auxiliary information. To limit the size of such signaling, in some cases there is a predefined set of messages, either for the user's device or for the system, which allows the user's device to sign for

- 12 using the message identifier only. This predefined message set is known to both the network and the user's device. The message identifier is associated with the corresponding message from this predetermined set, so that just communicating the message identifier is sufficient to notify the network of the content of the intended message. The simplest pre-set message may be one that requests immediate suspension of downlink transfer for a specific time.

[0056] In some examples, a 1-bit indicator for network signaling may be defined that a user equipment would like the downlink data rate to be reduced. In some examples, other data may be used in conjunction with this 1-bit pointer to provide additional information. For example, when this 1-bit pointer is provided, the current field, such as the CQI pointer, can be used to indicate how much downlink data rate should be reduced (i.e., the CQI pointer field indicates how the serving eNode-B node should respond to a request to reduce the downlink data rate, otherwise it still indicates the CGI value), Alternatively, when this 1-bit indicator is provided, the second field (e.g. CQI field) may represent the maximum value of the data rate that this device can support. FIG. 7 is a block diagram of an exemplary user device 701 supported by eNode-B 703. In this illustration, user device 701 is in the process of signaling to this eNode-B 703 that it would like the downlink data rate to be reduced. This exemplary signaling is in the form of a 705 field (e.g., 1 bit field) which, when activated, indicates the need to reduce the data rate. When data in field 705 is provided, another transmitted field (e.g. CGI 707 field) is interpreted by the eNode-B 703 as an indication of how much downlink data rate should be reduced or, alternatively, as the maximum data rate value, which Nadai user device can support.

[0057] In response to a signal from a user equipment (regardless of the form of this signal), the network responds by adjusting the downlink data rate in a manner consistent with this particular received message.

[0058] As mentioned above with respect to other examples, possible signaling in a mobile communication network is usually determined by the published standard for a given type of system. In the event that these standards do not provide a mechanism in which a user equipment may directly request a lower downlink speed, it is still possible for the user equipment to achieve this effect. In particular, the logic 300 and steps / processes described previously with reference to FIG. 3 are suitable for indirectly obtaining the effect that the network will reduce its downlink data rate. (The term "indirect" as used herein means that the user equipment is undertaking one or more actions that, as part of the communication standard in which the user equipment is operating, do not directly indicate to the network that there is some kind of congestion in the user equipment; despite this, the action (s) taken by the user equipment results in the network reducing the downlink data rate.) It should be recalled that the technique described with reference to FIG. 3 includes sending by the user device to eNode-B (or equivalent) notification of CGI value, the reported value (CQI_REporteo) is intentionally equal to a value that indicates a lower channel quality than the actual one (i.e. the true channel quality value should be equal to CGI_ACtual) (step 301).

[0059] Then, if there is a need to "convince" the network that the reported CQI value reflects actual channel conditions, the user equipment should operate in a manner that matches the reported CQI value (step 303). For example, the user equipment should send NAK signals to the serving node at a frequency (and perhaps also in time distribution) that corresponds to the channel whose quality corresponds to the reported CGI value. With some probability this means sending one or more NAK signals for data blocks whose reception is acceptable (i.e. received without errors or received with correctable errors).

[0060] Given that reporting a lower CQI value will cause the network to lower its downlink transmission speed, the user equipment is faced with the question of exactly what value is to be reported. In some embodiments, it can handle this by selecting a value from the given set of values ​​that is slightly lower than the actual CGI value. Alternatively, the user equipment may always report the lowest possible CQI value when it wants to reduce the downlink data rate. In contrast, in a number of embodiments of the invention, it is preferable to select a CQI value by determining which of a number of possible CQI values ​​will cause the user equipment to retain as much functionality as possible while suppressing the user equipment overload condition.

[0061] In other possible embodiments of the invention, the user equipment causes the network to reduce the downlink data rate indirectly, reporting NAK signals instead of positive signals (ACK) for certain data blocks whose reception was possible. For those data blocks that are falsely reported as "not received", the user equipment may either reject the original received data block and rely on the re-uploaded version or retain the originally transmitted version and discard the re-transmitted version. This technique allows the user's device to regulate the rate at which data is received. However, this technique has the disadvantage that the network continues to send data at a high speed, thus unnecessarily taking up the radio interface.

[0062] FIG. 8 is a block diagram of an exemplary user equipment 800 that includes elements that are particularly adapted to reduce or prevent resource overload in a user equipment 800. The user equipment 800 includes a number of the same elements as those previously described with reference to FIG. 2. Therefore, those elements that are common to both figures need not be described again. The user equipment 800 includes additional elements that are adapted to perform the steps / processes illustrated in FIG, 6. They include a threshold defining module 801 that receives one or more configuration signals that indicate what resources are available in the user equipment. This information may indicate things such as buffer size, signal processing capability, or any other resources on the user's device that may be overloaded due to excessive downlink data rates. Based on this information, the module defining the threshold value 801 generates one or more threshold values ​​that represent the level of resource utilization that corresponds to the user equipment 800 in an overloaded state of resource utilization (or alternatively which is to enter this state).

[0063] This one or more threshold values ​​are provided to the overload detection module

- 14803, which monitors one or more states in the transceiver 205, as well as from one or more signals that indicate the current levels of utilization of one or more resources associated with one or more applications, and determines on this basis (for by comparison with the appropriate of one or more threshold values) whether the current conditions constitute (or will constitute) an overload condition. The overload detection module 803 generates an overload condition signal that is supplied to the utilization control module 805. If an overload condition signal is active (which means that an overload condition has occurred or occurs), the 805 utilization control module generates control signals that cause the user's device will take steps to reduce (or prevent the occurrence of) an overload condition, e.g. those described with reference to FIG. 6. Control lines to decoder 209 and 211 enable the control module 805 to control individual decoding and coding rates as needed. For example, certain user device resources that are used for both uplink and downlink processing (e.g., buffering and processing module) may benefit from simultaneously considering the operation of both receive and transmit paths. The control line for the front transmitter 213 allows adjustment according to the need of transmitted power.

[0064] The present invention provides a number of methods that allow a user device to reduce or prevent the occurrence of a number of different types of overload conditions. In the event that this overload can be reduced or prevented by reducing the downlink data rate, there are a number of embodiments of the invention that achieve this even when the system does not provide the user's device with a mechanism to directly request the desired reduction in data rate.

[0065] The invention has been described with reference to specific embodiments thereof. However, for those skilled in the art, it will be apparent that the present invention may be implemented in specific forms other than those of the examples described above.

[0066] For example, separate examples have been described in which, in some of them, the reaction occurs over the thermal overload condition, while in others the reaction over the processing overload condition. However, in yet other possible cases, the user's device includes components that enable them to deal with both of these problems. For example, some embodiments of the invention include the equivalent of a temperature measuring module 401 and the threshold determining module (both shown in FIG. 5) as well as the equivalent of the threshold determining module (shown in FIG. 8). In such examples, the control logic may perform all functions assigned to the control module 503 and the use control module 805, which have been described above.

[0067] Thus, the described embodiments of the present invention are illustrative only and should not be construed as limiting in any way. The scope of the present invention is determined by the appended claims and not the above description, and all variants and equivalents that fall within the scope of the claims are intended to be included.