TWI389590B - Methods for mobile devices which is communicated with a base station wirelessly, apparatuses for communicating with a base station wirelessly and systems for operating in cdma mode - Google Patents

Description

Mobile device for wireless communication with base station, method and system thereof

The present invention relates to the field of cellular networks, and more particularly to systems and methods for simultaneously using multiple user cards in a mobile device.

In recent years, the use of mobile devices, in particular the use of cellular phones, has increased dramatically. In fact, some users hold multiple cellular accounts and/or cellular phone numbers. For example, some cellular users may hold a first account number or number for a private telephone call and a second account number or number for a business telephone call. Alternatively, the user may hold an account number for the first area and a separate account number for the other area. In these cases, the user may have to carry multiple cellular phones (for example, one account per mobile phone), replace the card (eg, SIM card) when using a different account, or load in the same phone. Multiple cards to use multiple accounts. However, such a mobile phone cannot use these cards at the same time. Therefore, improvements in mobile communication devices are desired so that users can use two cards or two accounts or numbers on the same handset.

In view of this, the present invention provides various embodiments of systems and methods for simultaneously using multiple cards in a mobile device. More specifically, the mobile device can include at least a first card and a second card.

Embodiments of the present invention provide a method for a mobile device for wirelessly communicating with a base station, the method comprising: receiving a first parameter set of a first user and a second parameter set of a second user; receiving a plurality of signals from the base station ,among them The plurality of signals are configured to indicate communication between the mobile device and the base station; calculate a plurality of communication parameters based on the plurality of signals and the first parameter set and the second parameter set; and The plurality of communication parameters of the user and the second user are in communication with the base station, wherein the plurality of communication parameters indicate wireless communication resources in a time multiplexed manner.

An embodiment of the present invention further provides a circuit coupled to a mobile device of a base station, the circuit comprising: an identification signal detector, configured to receive a first identification signal corresponding to the first module in the mobile device and corresponding to the mobile device a second identification signal of the second module; a receiver for receiving a plurality of signals from the base station, wherein the plurality of signals are configured to establish communication between the mobile device and the base station; And a plurality of communication parameters are calculated in response to the first identification signal, the second identification signal, and the plurality of signals received from the base station; and a processor configured to respond to the plurality of times of time multiplexing The slot and the plurality of parameters simultaneously attach the first and second modules to the base station, wherein the plurality of communication parameters are configured to determine whether the second module is attachable to the base station.

Embodiments of the present invention further provide a system operating in a Code Division Multiple Access (CDMA) mode, the system including a base station for receiving a first parameter set and a second parameter set and an action of wirelessly communicating with the base station Device.

The mobile device further includes: a parameter receiver for receiving a first parameter set of the first user and a second parameter set of the second user; and a signal receiver for receiving a plurality of signals from the base station, wherein the multiple Signals are configured to indicate communication between the mobile device and the base station; a calculator for calculating the plurality of communication parameters based on the plurality of signals and the first parameter set and the second parameter set; and the communication module Used to represent the first user and The plurality of communication parameters of the second user are in communication with the base station, wherein the plurality of communication parameters indicate wireless communication resources in a time multiplexed manner.

First application - mobile station

The method can determine a first International Mobile Subscriber Identity (IMSI). The first IMSI may correspond to a first card or telephone number in the mobile device. For example, the method can determine a phone number associated with the first card and determine a first IMSI based on the phone number accordingly.

Similarly, the method can determine a second IMSI of the second card or telephone number in the mobile device. For example, the second IMSI may be initiated or determined by a telephone number associated with the second card, or the second account of the mobile device.

The method can determine if the first card and the second card can be used simultaneously in a single transmitter/receiver of the mobile device. In one embodiment, it can be determined whether the two IMSIs and the second IMSI can be used simultaneously. For example, one or more parameters, such as communication parameters, for each of the first card and the second card may be determined based on the first IMSI and the second IMSI. The method can determine if the parameters of the first card are compatible with the parameters of the second card, or in one embodiment are conflicts. If the parameters are compatible, the first card and the second card can be available at the same time. Therefore, the method can configure the mobile device to use two cards simultaneously.

In one embodiment, this determination can be made based on a minimization of power consumption. For example, the determination can be based on whether two cards can be used during the same time slot to enable the mobile device to utilize two without using additional power. Each card performs communication. More specifically, the mobile device may use the first card and the second card having the appropriate parameter set without time multiplexing. In one embodiment, the determination may be based on the principle of minimizing conflicts. For example, instead of attempting to use two cards during the same time slot, the method can determine if the two parameter sets cause the first card and the second card to be used in a time slot that is one threshold away from each other, thereby ensuring no conflicts. But consume more power. Thus, in this example, the method can include determining a first time slot of the first card based on the first IMSI, determining a second time slot of the second card based on the second IMSI, and determining the first time slot and the second time slot Whether it is within the threshold time amount.

As a specific example, the paging slot and channel number can be determined for each card, for example, based on the first and second IMSIs. If the paging slot of the first card is the same or adjacent to the paging slot of the second card and if the first channel number of the first card and the channel number of the second card are different, the method may determine a parameter conflict, thereby The first card and the second card cannot be used simultaneously by the mobile device.

An indication or message can be provided as to whether the first card and the second card can be used simultaneously by the mobile device, such as displaying the indication on the display of the mobile device.

If the first card and the second card are simultaneously usable by the mobile device, the method can include configuring the mobile device to use the first card and the second card simultaneously. For example, the mobile device can be operated simultaneously by using the first card and the second card through time multiplexing using a single transmitter/receiver of the mobile device.

The method can be applied to one or more additional cards. For example, for one One or more additional cards may determine one or more additional IMSIs. Similar to the above, the method can determine whether the additional card can be used simultaneously by a mobile device having a first card and a second card, for example by determining a corresponding parameter set of the additional card, for example, the mobile device uses a single or shared transmission / receiver. If the parameters are compatible, the indication may also indicate that the one or more additional cards may be used simultaneously by the mobile device.

The above method can be implemented by a computer program, for example, program instructions stored on a storage medium such as a mobile device or a different computer system as needed. Program instructions are executable to implement the above methods. Similarly, the method can be performed or implemented by a mobile device.

Second application - base station

In one embodiment, the device can receive signals from the mobile device. For example, a base station, such as a macro base station or a femto cellular base station, can receive signals from the mobile device. In one embodiment, the signal may be part of an initial communication or setup phase for establishing communication between the base station and the mobile device, although for example the first card of the mobile device may receive the signal after the communication is established. .

However, in some embodiments, the signal received from the mobile device may indicate that the mobile device is capable of simultaneously using or requesting the use of two different cards, although other methods of determining may be foreseen. Therefore, the method can determine that the mobile device can use the first card and the second card at the same time. Additionally, in one embodiment, the signal can include a second aspect of the mobile device, the mobile device Information about a card, a second card of a mobile device, and the like. For example, the information may indicate a phone number associated with the first card and/or the second card.

A plurality of first communication parameters can be determined for the first card. In some embodiments, the first communication parameter can be determined based on an International Mobile Subscriber Identity (IMSI) of the first card. For example, the IMSI can be determined or derived based on the telephone number associated with the first card.

A plurality of communication parameters of the second card may be determined based on the first communication parameter. However, the communication parameters of the second card may not be based on the IMSI associated with the second card. Instead, the communication parameters of the second card can be determined or selected in such a way that it is ensured that the first card and the second card can be used simultaneously, for example while saving as much power as possible and/or ensuring that the first card and the second card are used. There are as few conflicts as possible between them. Thus, in one embodiment, the determination of the parameters of the second card may not be based on a telephone number associated with the second card, or any other information regarding the second card that has been received. In one embodiment, the IMSI may be selected for the second card, eg, not based on the telephone number associated with the second card, such that the communication parameters of the second card are compatible with the communication parameters of the first card.

In another embodiment, the true IMSI associated with the second card may be used, for example, to determine the communication parameters of the second card. However, if some of the communication parameters conflict with the parameters of the first card, they can be modified by the base station, or the new IMSI can be used for the second card, for example instead of the IMSI based on the phone number of the second card. The determined communication parameters of the first card and the second card may enable the first card and the second card to be enabled by a single transmitter of the mobile device / Receiver is used at the same time.

The determined parameters of the first card may include, for example, a first paging slot and a first paging channel. Accordingly, the paging slot and paging channel of the communication parameters of the second card can be assigned to the first paging slot and the first paging channel.

The first communication parameter can be provided to the mobile device. As indicated above, the communication parameters can be used by the mobile device to simultaneously communicate using the first card and the second card.

The above method can be extended to one or more additional cards, ie cards other than the first and second cards described above. Thus the method may also include determining communication parameters of one or more additional cards. This parameter can be determined to ensure that all or at least a portion of these cards can be used together as needed. Accordingly, these additional communication parameters can be provided to the mobile device.

The above method can be implemented by a program, such as a program instruction stored on a storage medium. Moreover, the method can be implemented by a system such as a base station, such as a macro unit base station, a femtocell, and the like. Therefore, the base station can ensure that a handset that desires to use more than one card at the same time can actually do so.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

First, the glossary used in this application is introduced: storage medium - any of various memory devices or storage devices. Kind. The term "storage medium" is intended to include: installation media such as a compact disc drive (CD-ROM), floppy or tape device; computer system memory or random access memory such as dynamic random access memory (DRAM, Dynamic Random Access) Memory), Double Data Rate Random Access Memory (DDR), Static Random Access Memory (SRAM), Extended Data Output Random Access Memory (EDO) RAM, Extended Data Output Random Access Memory, random memory such as Rambus RAM (Rambus RAM, etc.); or magnetic media such as hard disk drive or optical memory Loss of memory. The storage medium may also include other types of memory or a combination of such memories. In addition, the storage medium may be located in a first computer executing the program or may be located on a second different computer connected to the first computer via a network such as the Internet. In the latter case, the second computer can provide program instructions to the first computer for execution. The term "storage medium" may include two or more storage media, which may be located at different locations, such as at different computers connected through a network.

Programmable hardware components - including various hardware devices including a plurality of programmable functional blocks connected by a programmable interconnect. Examples include Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), Field Programmable Object Arrays (FPOAs), and Complex Programmable Logic Circuits (CPLDs). , Complex Programmable Logic Device). Programmable function modules can be from, for example Combining logic circuits or lookup tables and other fine particles to the arithmetic logic unit or the processor core and other coarse particles. A programmable hardware unit can also be referred to as "reconfigurable logic."

The program-term "program" is intended to have full coverage of its ordinary meaning. The term "program" includes (1) a software program that can be stored in memory and executed by a processor or (2) a hardware configuration program that can be used to configure programmable hardware components.

Software Program - The term "software" is intended to have full coverage in its ordinary sense and includes any one of program instructions, code, scripts and/or materials that can be stored in a storage medium and executed by a processor or combination. Exemplary software programs include: programs written in a text-based programming language such as C, C++, Pascal, Fortran, Cobol, Java, combined languages, etc.; also include graphics programs written in a graphical programming language; combined language programs; Programs compiled into machine language; scripts; and other types of executable software. A software program can include two or more software programs that work together in some way.

Hardware Configuration Program - A program that can be used to program or configure programmable hardware components, such as netlists or bitfiles.

Computer system - any of a variety of computing or processing systems, including personal computer systems (PCs), large computer systems, workstations, network devices, Internet devices, personal digital assistants, television systems, grid computing systems, or others. Equipment, or a combination of these devices. In general, the term "computer system" can be broadly defined to encompass any device or combination of devices having at least one processor that executes instructions from a storage medium.

Figure 1 - Exemplary Communication System

1 shows an exemplary communication system including a macro base station 100 providing services in a macro area 105, a plurality of access point base stations 170 providing services in a local area 175, and a plurality of mobile devices 150 (also called Is "mobile station" or "access terminal").

The term "access point base station" is intended to include a femtocell, a home base station, a personal access point (PAP), and a personal second-generation third-generation or n-th generation base as understood by those skilled in the art. A typical definition of Taiwan and other base stations. Similarly, the term "macro base station" is intended to include a typical definition of a cellular telephone tower and base station that is understood by those skilled in the art for providing services in a macro area. The term "base station" is intended to include access point base stations and macro base stations as well as other types of base stations as needed.

Mobile devices (also referred to as "access terminals") 150 can include any type of device that can be used in a cellular network, such as radio frequency communications. The mobile device can include a cellular handset, including a smart phone, a personal digital assistant (PDA) with mobile communication capabilities, a laptop or computer system with mobile communication components, or any other communication that can communicate with the cellular network. device. The mobile device can use a variety of different protocols, such as CDMA 2000, first generation RTT and EV-DO, UMB, UMTS, LTE, WiMAX or other protocols. Accordingly, base station 100 and mobile device 150 can, for example, support any one of the protocols used by the mobile device or at least a subset of these protocols without modifying the standards or protocols that support the existing mobile device. The mobile device 150 can be configured to support simultaneous use of multiple cards, as will be described in detail below.

Figure 2 - Determining the compatibility of multiple cards in a mobile device

Figure 2 shows an exemplary method for determining the compatibility of simultaneous use of multiple cards in a mobile device. The method shown in Fig. 2 can be used in conjunction with any of the computer systems or devices shown in the above figures, along with other devices. In various embodiments, some of the method elements shown in the figures may be performed simultaneously, or in a different order than those indicated in the figures, or some of the elements may be omitted. Additional method elements can also be executed as needed. As shown, the method can be performed as follows.

In step 202, a feature of the first card of the mobile device can be determined. For example, the telephone number of the mobile device can be determined, for example, by the first card of the mobile device. In some embodiments, the International Mobile Subscriber Identity (IMSI) of the first card of the mobile device can be determined. In various embodiments, for example, the US IMSI may be associated with a first phone number associated with the mobile device as needed or according to different methods, such as in China, depending on the data stored in a database accessible via the network. Sex launch. In general, the IMSI can be used to determine various communication parameters for communication performed by the mobile device, as described below.

At step 204, similar to step 202 above, the characteristics of the second card of the mobile device can be determined. For example, the IMSI of the second card of the mobile device can be determined by determining a telephone number associated with the second card of the mobile device and eliciting the IMSI from the telephone number. The IMSI derived or determined by the second card can then be used to determine communication parameters associated with the second card, as described below, but other methods for determining communication parameters can also be foreseen. Additionally in other embodiments, the characteristics of the second card can be determined based on characteristics of the first card. For example, some communication parameters determined by the first card can be applied to the communication parameters of the second card. number.

At step 206, the method can determine if the first card and the second card can be used simultaneously by the shared hardware of the mobile device. For example, it can be determined whether the first card and the second card can be used simultaneously by a single transmitter/receiver or baseband logic of the mobile device.

"Can be used simultaneously" means that the mobile device provides the first communication service to the user of the mobile device using the first card and also provides the second communication service to the user of the mobile device using the other one or more cards, wherein the first communication service and The second communication service appears to the user as if it occurred at the same time. It should be noted that the mobile device hardware can actually perform the hardware use of the time-division multiplex mobile device. For example, the same hardware of the mobile device, such as a transmitter/receiver, can be used to communicate using the first card in the first time slot and again for the second card communication in the second time slot, and this operation is considered to be The term "can be used at the same time" as used herein. Therefore, due to time division, the first card and the second card may not be in the exact same transient, but the user can experience the simultaneous use of the first card and the second card by using, for example, the above-described time multiplexing. In other embodiments, however, the hardware can be used by two cards during the same time slot, as described herein. Thus, for a user of two cards "can be used simultaneously", the two cards can be used by the same hardware to perform two separate communications simultaneously. In addition, it is noted that the "same hardware" mentioned above is more specific than simply using the same mobile device. More specifically, the same hardware refers to a hardware for communication of a mobile device, such as a baseband circuit, a transmitter/receiver, and the like. Therefore, the mobile device can eliminate the need for two separate communication circuits, such as two separate mobile baseband circuits, transmitters/receivers, etc. to simultaneously use two cards, but instead can use the shared Communication hardware.

At step 206, the method can include determining one or more communication parameters associated with the first card and determining one or more communication parameters associated with the second card. For example, the IMSI can be used to determine parameters such as channel numbers, such as CDMA channel numbers, paging channel numbers, quick paging channel numbers, paging slot numbers, paging indicator locations, individual time slots, and the like. These parameters can determine how and when the mobile device communicates with a base station, such as a macro base station, when using the first card or an account associated with the first card. Similarly, for example, the parameters determined based on the second card by the IMSI or the like associated with the second card can be used to determine how and when the mobile device communicates with the base station when using the second card or an account associated with the second card. However, some of the parameters determined for the first card or the first IMSI may be applied to the parameters determined for the second card or the second IMSI. Other characteristics or communication parameters, such as system time, pilot PN offset, long code status, etc., may be determined, for example, by the base station at time 206 or later.

Note that the communication parameters can be the same communication parameters used in future communication sessions. For example, the determination of the communication parameters can be performed in the same manner as used when communicating with the base station. In one embodiment, the determination of the communication parameters may actually include establishing a connection with the base station and receiving the assigned communication parameters. In one embodiment, the mobile device can be used to determine communication parameters without having to communicate with the base station, or any combination of mobile devices and base stations to determine communication parameters.

In one embodiment, the mobile device may determine a portion or all of the parameters using hardware stored on the mobile device or software stored thereon, for example, based on algorithms stored or implemented in the mobile device. It should be noted that Some communication parameters are always allocated in the same way, so the same communication parameters can always be assigned for each communication session. Therefore, the determination of these communication parameters can be completely determined. However, some parameters may be assigned differently or may be based on external factors, such as using other mobile devices of the base station, so the determination of these parameters may not be absolute. For example, the channel number can be modified during future communication sessions with the base station, for example via an overhead message.

Once the communication parameters of the first card and the second card are determined, the method can determine if the parameters are compatible or conflict with each other. For example, some parameters may be incompatible with each other and may result in the communication of the two cards always conflicting with each other or having a high or unacceptable probability of collision. Determining whether the communication parameter sets are compatible may be based on minimizing power consumption while having an acceptable probability of packet collision. For example, since some parameters such as channel numbers may vary during the allocation or initial setup of communication between the mobile device and the base station as described above, there may be a non-zero collision probability, but this configuration may minimize power consumption. More specifically, by selecting a parameter set having the same channel and, for example, using the same paging time slot, the communication parameters selected for power minimization are acceptable.

In one embodiment, power consumption can be sacrificed to ensure that the collision rate is minimized. For example, when the paging time slot is greater than or equal to the time separated threshold value, it can be determined that the communication parameters are compatible. More specifically, in one embodiment, the first time slot can be determined based on the IMSI of the first card and the second time slot can be determined based on the IMSI of the second card. The method can determine if the first time slot and the second time slot are within a threshold time amount to determine if the two communication parameter sets are compatible and whether the two cards are compatible. Therefore, the power consumption can be better than the above The example is much higher, but can guarantee a low probability of collision or a zero collision rate. Therefore, communication parameters that are selected based on the need to minimize collision rate or minimize power consumption as needed are acceptable, but allow an acceptable number of collisions, and need to be able to ensure functionality.

As a further example, the method can determine whether the paging slot determined by the first card and the paging slot determined by the second card are the same or adjacent. The method can also determine if the channel number of the first card and the channel number of the second card are different. If both of these conditions are met, there may be an unacceptable probability that the two cards will collide when used simultaneously, and more specifically based on the push parameters of the two cards may conflict. Similarly, if the communication parameters have the same or adjacent paging slots but have different paging channel numbers or different quick paging channel numbers, a collision may occur during simultaneous use. Note that these two scenarios are merely exemplary, and the method can utilize any number of specific cases or determinations to determine if the two parameter sets result in conflicts during simultaneous use.

At step 208, an indication can be provided indicating whether the first card and the second card can be used simultaneously by the mobile device. For example, the indication can be provided on a display of the mobile device. In one embodiment, the indication can be provided by a computer system, for example, including a card reader to determine the compatibility of cards used simultaneously in a single mobile device. The possibility of other indications can be foreseen. Thus, the above method can be used in each case to determine if two different cards or phone numbers are available at the same time. For example, the method can be performed when purchasing or selecting a secondary telephone number or a second card, during purchase of a mobile device, during deployment of a mobile device, and the like.

At step 210, the mobile device can be operated. According to various embodiments, The mobile device can operate in a single card mode, such as using only the first card or the second card, which is the case of a typical single card mobile device, or working in a simultaneous or dual mode where two cards can be used simultaneously. Thus, in this mode, the mobile device can simultaneously use the first card and the second, for example, by using the common hardware time multiplexing of the first card and the use of the second card using a mobile device such as a single transmitter/receiver. Card both.

Note that although the above method is described with reference to two cards, it is also possible to extend to more than two cards. For example, the same method can be applied to determine if three or more cards can be used simultaneously. Accordingly, the method can further include determining whether the first card and the second card are compatible with one or more additional cards and then providing the determined indication as needed.

In addition, the above method can be applied to any of various communication protocols. For example, the method can be used to support mobile devices for CDMA or CDMA 1x EVDO. In some embodiments, the mobile device can support the first protocol for the first card and the second protocol for the second card as needed. Therefore, the above method can be applied to any of various agreements as needed, regardless of whether the same or different properties are used.

Figures 3-11 - Further Embodiments

Figures 3-11 and the following description provide various embodiments of the method described in Figure 2. Note that these embodiments are merely exemplary, and variations in configuration and process are foreseen.

As described above, when two or more IMSI numbers are included in the same baseband device, one telephone number (IMSI) of the first card can be defined as the primary number, and the second telephone number of the second card (IMSI) Can be defined as a vice number. When more than two IMSI numbers are included in the same baseband device, one telephone number (IMSI) can be defined as the primary number, the second telephone number (IMSI) can be defined as the secondary number, and the third number and the number Four numbers and so on. The primary number can always be fixed to, for example, a preset value or a normal value without requiring a change. The method can estimate the resource allocation difference between the primary IMSI and the secondary IMSI or multiple IMSIs. In one embodiment, the difference can be compared to a predetermined threshold to determine if the second number or plurality of phone numbers are compatible with the primary number. If the result is within the threshold range, the secondary IMSI or multiple IMSIs may be accepted; otherwise, the paired or secondary telephone numbers may be rejected.

Pre-detection of compatibility of multiple UIM cards

The pre-detection of the compatibility of the second or more numbers with the primary telephone number can be implemented as part of a user interface (UI), a personal computer, a network, and the like. Thus, instead of performing all steps of the system acquisition process on the selected number, the mobile station can use the UI interface or other elements to wake up a small portion of the wafer or mobile station for calculation, such as converting the phone number to a UIM number and a hash function. (Hash function) can be used to calculate the remaining parameters. This result can result in two outcomes: (1) the selected phone number may be accepted and may proceed to multiple UIM card acquisition phases, or (2) the selected phone number may be rejected.

Multiple UIM card initial acquisition process

In order to acquire a CDMA system, the mobile station can experience the following states: The CMDA system selects the status, the pilot channel acquisition status, the synchronized channel acquisition status, the system timing change status, and finally the mobile station idle status. The mobile station can synchronize its long code timing and system timing with those of the CDMA system using the received synchronization channel messages, such as the pliot_PN, LC_STATE, and SYS_TIME values obtained from the base station.

For dual UIM card operation, the primary UIM user can first acquire the CDMA network and obtain the CDMA system time, pilot PN offset, and long code status. The information obtained by obtaining the main UIM can be directly applied to the secondary UIM initial acquisition without going through the actual initial acquisition steps. This is based on the assumption that the two UIM cards are located at exactly the same location and that they should camp to the same strongest base station during the initial acquisition phase.

By entering the idle state, multiple UIM cards can then perform a registration process to inform the base station of their location, status, identity, time slot loop, and other features so that the base station can efficiently page the mobile station. Registration may be performed first for the primary UIM card and then for the secondary UIM card.

Multiple UIM mobile station operations

The move operation can have three system acquisitions: only the primary UIM, only the secondary UIM, and the dual mode. As shown in Figure 3, after power-on: If the System Acquisition Preference has only the primary UIM, the mobile station can transition to only the primary IS-2000 1x operation.

If the system acquisition preference is only a secondary UIM, then the mobile station can transition to only the secondary IS-2000 1x operation.

If the system acquisition is preferably a dual UIM, the mobile station can transition to dual primary/secondary IS-2000 1x operations and can operate according to the methods described herein. Work.

In various embodiments, the user may be able to select among different modes; for example, if the two cards are compatible, only the primary card, only the second card, or multiple cards are used. When two or more cards are incompatible, the user may be able to select, for example, which card can be exclusively used.

Figure 4 shows the dual UIM state diagram. As shown, after "power on", if the system acquisition is preferably a dual UIM, the state can transition to "sub-initialization" or "primary initialization." From the "sub-initialization", a secondary acquisition can occur to transition to the state "main & secondary idle". Similarly, from the "main initialization", after the main acquisition, the status may be "main idle & sub-initialization", which may also shift to "main & secondary idle" after the secondary acquisition. From "Main & Secondary Idle", the status "Sub Access" and "Primary Access" are available. From these states, "secondary start" and "main start" are available. Various conditions determine the operation that causes a state transition during dual UIM operations.

Conflict judgment mechanism

Collision decisions for simultaneously using UIM cards in the same device can be divided into two groups: minimizing power consumption while allowing a certain ratio of collisions, and sacrificing power consumption while ensuring collision rates.

Minimizing power consumption while allowing a certain ratio of collisions - assuming that the mobile user can have many choices to select the correct UIM card with the same Paging paging slot, for example using a hash function for calculating parameters as having the same CDMA channel and The primary number of the slot when paging. In this case, at each time slot loop, the mobile station may need to wake up only once to receive two or more UIM card messages without additional power consumption to update the second card information. However, during the monitoring phase, the base station can change through the burden message. CDMA channel number. Therefore, the same CDMA number cannot always be guaranteed. A collision may occur when the CDMA channel number becomes a different number than the original number derived by the hash calculation.

Sacrificing power consumption while guaranteeing collision rate - since the mobile station does not have the ability to change any allocated resources with a given IMSI, an easy way is to reject those cards whose IMSI is incompatible with the primary IMSI number, or reject the possible The primary IMSI number is incompatible with the card and selects another UIM card that is compatible with the primary number. This approach may result in more power consumption than the first method because the base frequency of the mobile station or mobile station may need to stay longer to update the information of two or more UIM cards. However, since the two or more cards are separated from the main paging slot by Δ time, this gives each mobile station a relatively sufficient decoding time to separately decode the paging/burden. Therefore, the issue of resource sharing may no longer be an issue. Theoretically, there is no resource overlap problem in 94% of the two cards with a separate paging slot 240ms in the slotted loop index 2, where the time slot 2.56s is the actual primary in the CDMA system. The time slot of the time slot used is 240ms for three paging slots, ie 3 ^* 80ms. In other words, in the worst case, the rejection rate is about 6%, which is acceptable. The simulation results show that under the simulation condition of scanning 10000 telephone numbers with random channel numbers 1-10 and paging numbers 1-3, the collision probability is 0.6%, and the collision occurs 55 times. The decision mechanism is shown in Figure 5.

As shown, at step 502, a secondary MSI number, 10 digits, can be received.

At step 504, a CDMA channel number, a paging channel number, a Quick Paging Channel (QPCH) number, a paging slot number, and a paging indicator can be determined. Symbol location.

At step 506, the paging slot number from the secondary IMSI can be compared to the primary paging slot number from the primary IMSI.

If the difference is less than or equal to the threshold, then at step 508, the secondary CDMA channel number can be compared to the primary CDMA channel number. If the difference is greater than the threshold, then at step 520, the secondary IMSI/number can be accepted by the device.

If the difference is less than or equal to the threshold value, the calculated CDMA channel number is compared with the primary CDMA channel number in step 510, and when the difference between the numbers is not 0 in step 512, the number is not accepted by the device, and It may be desirable to select another number in step 518.

However, when the difference of the above numbers is 0 in step 512, the comparison paging channel number and the quick paging channel number may be associated with the primary paging channel number and the quick paging number. If there is no difference in this comparison, the number is not accepted in step 518.

If there is a difference in step 516, the number can be accepted in step 520.

Conflict area

As described above, in order to demodulate at least one data frame indicating that the mobile station may go to sleep, the mobile station may need to go through three phases: a resynchronization phase, a monitoring phase, and a teardown phase. During the three phase operations plus some buffering time, the mobile station cannot mix to any CDMA channel/paging channel number except its current CDMA channel/paging channel number, otherwise there may be a collision. The collision zone may include a delta time slot before the main paging slot and a delta time slot after the main paging slot, as shown in FIG.

Also as mentioned above, the hash function can be used to calculate the corresponding correspondence The parameters of the IMSI number. Within the collision zone, only two IMSIs with the same CDMA channel/paging channel number are acceptable. However, outside the conflict zone, there is no limit to the CDMA channel number/paging channel number. Since the mobile station can have relatively sufficient time to switch antennas for different frequencies or can handle different Walsh codes, this time depends on the distance between the two IMSI cards. The farther the distance, the better, so it can be based on the hash function. Determined to allocate all resources. The distance between the primary paging slot and the secondary paging slot is a major factor in the level of conflict confidence. The distance defined to the conflict zone is different from the character. Figure 6 shows an exemplary conflict zone and acceptable time slots over time. Compatibility can be determined or defined as a poor preference level. An example of such a rating is as follows.

1) Most preferred telephone number: The paging slot of the selected telephone number is located in a time slot from/to the collision zone that satisfies the following conditions: there is a maximum time gap between the two/multiple collision zones. For ^{example, △ = <(1.28 * 2} ^ i / 2-1,1.28 * 2 ^ i / 2,1.28 * 2 ^ i / 2-1), i is an index in the time slot loop is given by the base station.

2) Preferred telephone number: The paging slot of the selected telephone number is located in the time slot from/to the collision zone where the following conditions are met: a second largest time gap between the two/multiple collision zones .

3) Acceptable phone number: The paging slot of the selected phone number is located in the time slot from/to the collision zone that meets the following conditions: it is outside the collision zone, but has two conflict zones. The smallest time gap.

4) Unacceptable phone number: The selected phone number is in the conflict zone.

Threshold value determination

As discussed in the previous section, threshold values can also be divided into two groups based on the design focus of power consumption based on collision rate.

Minimizing power consumption - The idea of minimizing power consumption is to have the same PGSLOT number for both UIM cards. To accomplish this, the mobile station can scan all possible secondary numbers and find the number with the same CDMA channel/paging channel as the primary number. A threshold value may be set to measure the number distance of the candidate UIM card PGSLOT and the primary PGSLOT, and select the same time slot or the adjacent time slot with the smallest Δ.

Minimizing Conflict Rates - As noted above, in a CMDA system, resources can be predetermined by a given UIM card. Therefore, when a conflict occurs, it will persist in future communications and there is no recovery strategy. Therefore, minimizing the collision rate can be the main design goal of the mobile station. To accomplish this, the mobile station can scan all possible secondary numbers and find a number with the same or adjacent PGSLOT number as the primary number. A threshold value is set to measure the candidate UIM card PGSLOT distance from the primary PGSLOT number and to eliminate numbers with different CDMA channels or paging channels within the threshold collision area.

Dual UIM card slotted operation

It is assumed that the mobile station acquires both the primary system and the secondary system. The process of monitoring the primary paging channel slot and the secondary control channel can be determined by the state of the dual mode, as shown in Figures 3 and 4: only the primary UIM mode, only the secondary UIM mode, and the dual UIM mode. In the dual UIM mode, the mobile station can camp on the primary channel and tune to monitor the secondary control channel in the predetermined time slot. Therefore, in dual UIM mode, the mobile station may need to receive two UIM pages.

Figure 7 shows an example of a dual UIM data flow and interaction. As shown, Figure 7 shows a dual UIM mode with general data and control flow between the primary and secondary units. Resource allocation is distributed between CP MON, MPA, DSPM, and 1X protocols.

CP MON - is responsible for determining if the request unit should go deep sleep. Both the primary UIM and the secondary UIM system should send the next resynchronization time and deep sleep request to CP MON. Since CP MON has an awareness of the wake-up time required by both systems, the time difference between the current time and the expected wake-up time can be calculated. If the difference is greater than the pre-fixed delta, for example 5 ms, the CP MON idle test can agree to the deep sleep request and turn off all hardware and clock. Otherwise, the wafer can remain awake.

MAP - At each waking event, the MAP may be a central unit for processing resource requests from the primary UIM or the secondary UIM, and may decide whether to approve or reject the request according to its priority order. In dual UIM mode operation, if one of the systems is in an active or business state, it can always reject resource requests from another because the system can only support one UIM at a time and work on a first come, first served basis. When the system releases resources, the MAP should always be notified so that the MAP can keep up-to-date useful information.

DSPM - The resource responsible for delivering MAP requests from two UIM systems.

1X_PS - is responsible for handling all 1x related messages and resource requests.

Dual UIM resynchronization

Since the dual UIM allows sharing of common or identical hardware, short code and long code generators can be shared between the two UIM systems. Therefore, it may be necessary to track the system time of the two UIMs independently. In addition, the resynchronization parameter calculation for each UIM system can be related to its own system time.

Long code jump

In the 1X system, the time slot is at 1.28 s. In the duration of 2 ⁱ (i=0,1,2,...,7), the maximum duration is 163s. The duration of the long code generator is much longer than the sleep period, which is 242/1.2288 MHz = 41.425 days. Since the code generator may be powered down while the mobile station is powered down, it may be necessary to calculate a new state before sleep. An effective way to calculate the long code state is to use the long code generator state before sleep to calculate the new state after sleep.

Resynchronization event

A "resync" event in the hardware can include setting most system time states to programmed values. The main system time counter and short code generator of 80ms@9.8304MHz and the long code status may need to be set to some programmed values corresponding to the time at which resynchronization occurs.

Before entering sleep, the CP can calculate the initial state of the PNI, PNQ, and system counters at a predetermined resynchronization time. At the resynchronization time, the hybrid sleep control logic can generate a hardware resynchronization interrupt to the system time unit. The resynchronization interrupt can cause the load pulse to reach the system time unit where the counter and PN generator can be set. It is also possible to trigger a RESYNC_INT interrupt to the CP.

Dual UIM time slot segmentation mode without competition mechanism

In some embodiments, there may be no overlapping wake up time between the two systems. When waking up from sleep or on request, the resources of both systems can be guaranteed. However, when the Δ time between the two wakes is very close, it may be desirable to keep the wafer awake until the next wake up. Thereby, the amount of time to wake up the ASIC can be saved. In this design, CPMON can be responsible for the same Deep sleep request. When a deep sleep request is received, CPMON can calculate the waking time to the next programming, which can be the Δ time of the primary UIM or the secondary UIM. If it is greater than the threshold value, for example 5 ms, then the deep sleep request can be agreed; otherwise, the wafer can remain awake until the next wake up time.

Figure 8 shows an example of a timeline for dual UIM full time slot splitting.

Competing dual UIM time slot segmentation mode

When the mobile station is in dual UIM mode and active in the network, a partial time slot split mode can occur while checking for time slot split paging for the dual mode UIM card. This can lead to competition between the two systems. In a dual UIM card design, the UIM card in active phase/monitor can have a higher priority than the UIM system that is in an idle state and waiting for its startup. Therefore, when monitoring the UIM system, you can disagree with the wake-up request of another UIM system. Instead, the Sleep Control Logic (SSM) module can calculate the next wake-up resynchronization time of the UIM and can program the resynchronization time into the system time unit and/or the dual mode control unit, then place the UIM system In the sleep state until the resources are released. Figure 9 shows an example of a timeline for slot splitting for dual UIM resource contention.

When the SSM module requests a deep sleep, it can send a predetermined resynchronization time and a deep sleep request to the CP MON so that the CP MON can use the timing reference to determine whether to approve the request that can be used to mix the deep sleep request. The DSP can be used as a central unit to transfer information between the CP and the hardware. Figure 10 shows a paging ladder diagram with time slot partitioning for contention events between two systems.

Paging start timeline for CDMA time slot splitting

Time slot split paging operations may require the mobile station to be scheduled for paging The slot is woken up to acquire the network again and monitor the control channel at the beginning of the selected control channel loop. The mobile station can return to sleep when the burden message has been updated and a general page message with the appropriate done bit, for example, at least 1 frame (20 ms) of the demodulated material is received. In order to monitor the paging channel or the forward shared control channel at each start of the time slot loop, the mobile station may need to start earlier than the required time slot to perform some necessary finishing procedures to make the required time slot All information is ready for proper decoding. Figure 11 shows the CDMA operation and timeline for the start of the time slot split mode. The typical wake-up time for a CDMA time slot split system is approximately 80 ms.

Figure 12 - Determining the compatibility of multiple cards in a mobile device

Figure 12 shows an exemplary method for determining the compatibility of simultaneous use of multiple cards in a mobile device. The method shown in Fig. 12 can be used in combination with any one of the computer systems or devices shown in the above figures. In various embodiments, some of the method elements shown in the figures may be performed simultaneously, in a different order than that indicated in the figures, or some of the elements are omitted. Additional method elements can also be executed as needed. As shown, the method can be performed as follows.

At step 1202, a signal can be received from the mobile device, for example, by the base station. For example, a mobile device may attempt to communicate or establish communication with a base station. In various embodiments, the mobile device can transmit information regarding various communication capabilities of the mobile device. For example, the signal may indicate that the mobile device can or request to use the first card or the account associated with the first card and the second card or account associated with the second card. Therefore, in step 1204, the method can determine that the mobile device can simultaneously use or request to use the first card and the second simultaneously card. However, the signal in step 1202 may provide further information, such as information regarding the first card and/or the second card. For example, although as described in FIG. 2 above, the signal may indicate a telephone number and/or IMSI associated with the first card and the second card, in some embodiments, the IMSI may be determined based on the telephone number.

At step 1206, a plurality of first communication parameters can be determined for the first card. Similar to the above description, the communication parameters can be determined by various methods, such as based on the IMSI associated with the account number of the first card or the first card.

At step 1208, a plurality of second communication parameters can be determined for the second card. A plurality of second communication parameters can be determined based on the first communication parameter. More specifically, a plurality of second communication parameters can be determined to allow the first card and the second card to be simultaneously used by a shared hardware of the mobile device, such as a base frequency, a transmitter/receiver, and the like.

In various embodiments, this may be accomplished by ejecting communication parameters based on the IMSI of the second card, modifying those parameters to make the communication parameters of the first card and the second card compatible, if necessary. In one embodiment, the communication parameters may not be based on the IMSI of the second card or other information received about the second card, but may instead be based on the communication parameters determined for the first card. Thus, the second communication parameter can be significantly determined, for example, based on an indication that the mobile device desires to use or can simultaneously use the first card and the second card to ensure that the first card and the second card can be used simultaneously by the mobile device. For example, a plurality of second parameters can be assigned such that the paging time slot and paging channel of the second card are the same as the paging time slot and paging channel of the first card. As another example, the IMSI of the first card can be assigned as the IMSI of the second card. More specifically, the system can map the mobile directory number (MDN) of the second card. Hit the IMSI of the first card.

At step 1210, a plurality of first and second communication parameters can be provided to the mobile device. A plurality of first communication parameters can be used by the mobile device to communicate using the first card, and a plurality of second communication parameters can be used by the mobile device to communicate using the second card. Due to the determinations in steps 1204 and 1206 above, the mobile device can be configured to use the first and second communication parameters to simultaneously use the first card and the second card or an account associated therewith.

Similar to the above embodiments, the method can be applied to more than two cards in a mobile device. For example, the method can include determining that the mobile device can simultaneously use the first card, the second card, and the one or more additional cards, determining relevant communication parameters for the one or more additional cards such that the plurality of cards can be Use these parameters simultaneously and to the mobile device. Thus, the method is applied to determine any number of communication parameter sets such that any number of cards can be used simultaneously by the mobile device. However, such a method can be changed to allow any subset of cards to be used simultaneously, for example, the first card and the second card can be used simultaneously, and the third and fourth cards can be used simultaneously, as desired.

Further embodiment

The following description provides a further embodiment of the method described in Figure 12. Note that these embodiments are merely exemplary, and variations in configuration and process are foreseen.

Implementing a process associated with a dual/multi-UIM card of a mobile station in a base station can have more advantages than being implemented in a mobile station. However, such changes may require standard changes for communication, which may be undesirable.

Conflict judgment mechanism - the base station can refer to the phase according to the user's main number The same user assigns a secondary number. Since the base station has an awareness of the frequency/Wash allocation, it prevents possible collisions by avoiding IMSIs that may collide with the primary number. In addition, the base station can select a particular number that has the same paging slot as the primary number.

Advantages over mobile station embodiments - power saving - The base station can select the secondary number in such a way that the primary and secondary numbers have exactly the same paging slot number as the shared CDMA channel number and paging channel number. In this way, the mobile station can have the power consumption of a single user while supporting both UIMs.

The scheduling-mobile station may only need to wake up once to decode the paging or control channel messages addressed to the two IMSIs. There is no need to handle switching between two IMSIs.

Additional embodiment - multiple UIM cards in mixed 1xRTT and 1xEV-DO systems

Unlike the 1x mode operation in which the slot number and time slot are fixed in advance and the mobile station does not change its options, in the DO system, the preferred control channel loop is negotiable because AN (access) Network) I don't know the 1x time slot in use. Therefore, the AN may have to accept the preferred Control Channel Loop (PCCC) suggested by the mobile station. Figure 13 shows Rev 0, the preferred loop determination for the hybrid control channel.

Multiple UIM cards with primary EVDO card

The average time required to fix the EVDO PCCC-Decoded Good Frame with the main UIM card is approximately 80ms~100ms. In QPCH mode, the paging indicator character can be within 100 ms before the paging channel frame. Therefore, in order to avoid conflicts, normal paging and QPCH can be combined to Given some Δ time between 1X and EVDO wake up time, for example it can be set to 300ms. During the 300ms time zone, any DO scheduled wake up can be considered to overlap with 1X and can be rescheduled to a new time that will not collide with 1X.

In order to compare the wake-up time of the two systems on the same scale, we express the two systems with a slot duration of 1.667 ms. The wake-up time of 1X can be expressed as follows: MS _slot = 48 × mod ( PGSLOT , 16 × 2 ⁱ ) + 48 × k × 16 × 2 ⁱ

Where k is the number of slot loops at 16x2i from the beginning of the system time.

In QPCH mode, the collision can be considered to have a first pointer location because it can be quite complicated when considering the possibility of waking up on the second page indicator. In addition, there is not enough time between the two indicator characters to decode the control channel capsule.

MS _slot = 48 × mod ( PGSLOT , 16 × 2 ⁱ ) + 48 × k × 16 × 2 ⁱ // / / / / / /

The wake-up time of DO can be expressed as follows: AT _slot = 256 × mod ( R , 12) + 256 × j × 12 + offset

Select a secondary UIM card that does not overlap with the main UIM

The same method for selecting the secondary UIM can be applied to the EVDO/primary/secondary UIM selection. The difference is that the selected UIM has to satisfy enough processing space with both the 1x main UIM and EVDO systems.

Multiple EVDO cards with a primary UIM card

After determining the primary EVDO PCCC that is compatible with the selected 1x primary UIM card, using the method described above, the mobile station can calculate the most preferred secondary EVDO PCCC number that should not overlap with the primary EVDO or the primary 1x UIM. The selected pair can be selected by negotiating the preference with the AN during the session establishment phase. The PCCC is assigned to the user.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100‧‧‧Macro base station

105‧‧‧Macro area

150‧‧‧ mobile device

170‧‧‧Access Point Base Station

175‧‧‧Local area

202-210‧‧‧Steps for implementation

502-520‧‧‧Steps for implementation

1202-1210‧‧‧Execution steps

1 shows an exemplary communication system including an access point base station in accordance with an embodiment of the present invention.

2 is a flow chart showing an exemplary method for determining whether two cards can be used simultaneously in a mobile device in accordance with an embodiment of the present invention.

Figures 3-11 show exemplary diagrams of the method corresponding to Figure 2, in accordance with various embodiments of the present invention.

Figure 12 is a flow chart showing an exemplary method for determining communication parameters of two cards in a mobile device in accordance with an embodiment of the present invention.

Figure 13 is a diagram showing an exemplary diagram corresponding to the method of Figure 12 in accordance with an embodiment of the present invention.

202-210‧‧‧Steps for implementation

Claims (21)

A method for a mobile device in wireless communication with a base station, the method comprising: receiving a first parameter set of a first user and a second parameter set of a second user; receiving a plurality of signals from the base station, the plurality of signals Means for indicating communication between the mobile device and the base station; calculating a plurality of communication parameters according to the plurality of signals and the first parameter set and the second parameter set; and according to the first user and the second user The plurality of communication parameters to communicate with the base station, wherein the plurality of communication parameters indicate that the plurality of communication parameters are calculated according to a time multiplexing manner using wireless communication resources and wherein a diversity manner of wireless communication resources used according to the time multiplexing manner is calculated, The plurality of communication parameters are less than a threshold for reducing power consumption of the mobile device. The method of claim 1, wherein the first parameter set is converted by the first user number of the first user, and the second parameter set is converted by the second user number of the second user. The method of claim 1, wherein the plurality of wireless signals indicate a common communication parameter among the first user and the second user, which is selected from: a system time of the base station; a pilot PN offset; And long code status. The method of claim 1, wherein the plurality of communication parameters comprises a paging channel number and a CDMA signaling channel number. The method of claim 1, wherein the plurality of communication parameters are calculated according to a diversity manner of a wireless communication resource used in a time multiplexing manner, the plurality of communication parameters being greater than a threshold for reducing a collision rate of the wireless communication resource value. The method of claim 5, wherein the diversity is related to any one of: a paging channel number corresponding to the first user and the second user; and corresponding to the first user and the second user CDMA signaling channel number. The method of claim 1, further comprising calculating a wake-up period of the mobile device based on the plurality of communication parameters, wherein the wake-up period is related to a diversity manner of wireless communication resources used in a time-multiplexed manner. The method of claim 7, further comprising: maintaining the mobile device awake during the awake period when the length of the awake period is less than a threshold value. The method of claim 1, further comprising: when the mobile device is awake and communicating with the base station through the first parameter set, the second parameter set is idle, when the mobile device ends transmitting When the first parameter set is in communication with the base station, the mobile device receives the resynchronization interrupt in response to the second parameter set. The method of claim 9, wherein the resynchronization interrupt is used to reset the time counter and the code generator. An apparatus for wirelessly communicating with a base station, comprising: a parameter receiver for receiving a first parameter set of a first user and a second parameter set of a second user; and a signal receiver for receiving more from the base station Signal, which is The plurality of signals are used to indicate communication between the device and the base station; the calculator is configured to calculate a plurality of communication parameters according to the plurality of signals and the first parameter set and the second parameter set; and a communication module, And for communicating with the base station according to the plurality of communication parameters used to represent the first user and the second user, wherein the plurality of communication parameters indicate use of wireless communication resources in a time multiplexed manner and wherein the time is used according to a time multiplexing manner The plurality of communication parameters are calculated in a diversity manner of the wireless communication resources, the plurality of communication parameters being less than a threshold value for reducing power consumption of the mobile device. The device of claim 11, wherein the first parameter set is converted by the first user number of the first user, wherein the second parameter set is converted by the second user number of the second user. The apparatus of claim 11, wherein the plurality of wireless signals indicate a common communication parameter of the first user and the second user, which is selected from: a system time of a base station; a pilot PN offset; Long code status. The device of claim 11, wherein the plurality of communication parameters comprises a paging channel number and a CDMA signaling channel number. The apparatus of claim 11, wherein the plurality of communication parameters are calculated according to a diversity manner of a wireless communication resource used in a time multiplexing manner, the plurality of communication parameters being greater than a threshold for reducing a collision rate of the wireless communication resource value. The device of claim 15, wherein the diversity and Any one of the following: a paging channel number corresponding to the first user and the second user; and a CDMA signaling channel number corresponding to the first user and the second user. The apparatus of claim 11, further comprising calculating a wake-up period of the apparatus based on the plurality of communication parameters, wherein the wake-up period is related to a diversity manner of wireless communication resources used in a time-multiplexed manner. The device of claim 17, further comprising: maintaining the mobile device awake during the awake period when the length of the awake period is less than a threshold value. The device of claim 11, further comprising: when the device is awake and communicating with the base station through the first parameter set, the second parameter set is idle, when the device ends through the first When the parameter set is in communication with the base station, the device receives a resynchronization interrupt in response to the second parameter set. The apparatus of claim 19, wherein the resynchronization interrupt is used to reset the time counter and the code generator. A system for operating in a CDMA mode, the system comprising: a base station for receiving a first parameter set and a second parameter set; a mobile device for wirelessly communicating with the base station, further comprising: a parameter receiver, Receiving a first parameter set of the first user and a second parameter set of the second user; the signal receiver is configured to receive a plurality of signals from the base station, wherein the plurality of signals are used to indicate the mobile device and the base Communication between the stations; a calculator for calculating a plurality of communication parameters based on the plurality of signals and the first parameter set and the second parameter set; a communication module, configured to communicate with the base station according to the plurality of communication parameters used to represent the first user and the second user, wherein the plurality of communication parameters indicate a wireless communication resource in a time multiplexing manner and wherein the time is complex The plurality of communication parameters are calculated in a diversity manner of wireless communication resources used in a manner that is less than a threshold value for reducing power consumption of the mobile device.