Patent Application
20170164324
Field
The present disclosure relates generally to methods and apparatus for optimizing Long Term Evolution (LTE) data performance in a wireless device, and more specifically to optimizing LTE data performance in Single Radio LTE (SRLTE) devices.
Background
Certain wireless devices have the capability to receive signals from two or more Radio Access Technologies (RATs) using a single radio. One example of such devices is known as Single Radio Long Term Evolution (LTE) or SRLTE. In SRLTE devices, a User Equipment (UE) or Mobile Station (MS) may simultaneously receive signals from an LTE wireless network and a Code Division Multiple Access (CDMA) 2000 1x wireless network.
In a 1x SRLTE device (i.e., 1x CDMA Single Radio LTE or similar GSM devices), the UE has to tune away to a 1x CDMA system to perform paging monitoring. Typically, the 1x tuning away time is between 60 to 130 milliseconds (ms), even under favorable conditions such as no cell change, no re-read OVH, or no signaling exchange. Thus, if the LTE portion of a UE is in a connected mode transferring data, the LTE data transmission will be suspended while the UE performs a 1x CDMA tune away, resulting in LTE data throughput degradation even under the best conditions.
Additionally, it is noted that paging delay in SRLTE devices is dependent on the slot cycle index (SCI) for the Paging Channel in the system, which is typically determined by the network. For 1x CDMA, for example, the Paging Channel, which is a shared channel that all MS's listen for various information including pages, is divided into “slots”. The SCI determines how frequently the MS's assigned slot occurs in a network. For example, if the SCI=0, the MS wakes up every 1.28 seconds, if the SCI=1, the MS wakes up every 2.56 seconds, and so on up to a typical maximum value of 7 (i.e., 163.84 seconds). Thus, the larger an SCI, the less frequently a UE/MS will tune away to check 1x paging. Conversely, the smaller the SCI value, the more frequently a UE/MS will tune away to check 1x paging, which further degrades LTE data throughput. This may also be exacerbated by the fact that networks typically set an SCI value that is not increasable, and the standards direct that the smallest number be used for the SCI value. Furthermore, even if a network allows increase in the SCI to reduce the frequency of tune away, networks will also establish maximum SCI values (MAX_SLOT_CYCLE_INDEX) that cannot be exceeded, which hampers efforts to increase LTE data performance even though the SCI may be adjusted.
There is a need in the art for methods and apparatus for better optimizing dual network devices by allowing the frequency of tune away to a first network (e.g., 1x CDMA) for paging monitoring to be reduced, thereby increasing data performance for reception over the second network (e.g., LTE).
According to an aspect, a method for optimizing the performance of a radio access technology in a wireless communication system supporting multiple radio access technologies is disclosed The method includes monitoring a call paging channel from a first radio access technology received at a wireless device, and then determining at least one system parameter received over the call paging channel, the at least one system parameter related to a maximum allowed periodicity of when the wireless device may tune away from a second radio access technology to monitor paging from the first radio access technology. Additionally, the method includes determining whether the maximum allowed periodicity determined from the at least one system parameter is greater than a preferred tune away periodicity stored in the wireless device. If the maximum allowed periodicity is greater than the preferred tune away periodicity, the method includes increasing the at least one system parameter in the wireless device.
According to another aspect, a device configured for optimizing the performance of a radio access technology in a wireless communication system supporting multiple radio access technologies is disclosed. The device includes at least one processor configured for monitoring a call paging channel from a first radio access technology received at a wireless device. The processor is also configured for determining at least one system parameter received over the call paging channel, the at least one system parameter related to a maximum allowed periodicity of when the wireless device may tune away from a second radio access technology to monitor paging from the first radio access technology, and determining whether the maximum allowed periodicity determined from the at least one system parameter is greater than a preferred tune away periodicity stored in the wireless device. Additionally, the processor is configured for increasing the at least one system parameter in the wireless device when the when the maximum allowed periodicity is greater than the preferred tune away periodicity.
According to yet another aspect, an apparatus for optimizing the performance of a radio access technology in a wireless communication system supporting multiple radio access technologies is disclosed. The apparatus includes means for monitoring a call paging channel from a first radio access technology received at a wireless device. Further, the apparatus includes means for determining at least one system parameter received over the call paging channel, the at least one system parameter related to a maximum allowed periodicity of when the wireless device may tune away from a second radio access technology to monitor paging from the first radio access technology. The apparatus also includes means for determining whether the maximum allowed periodicity determined from the at least one system parameter is greater than a preferred tune away periodicity stored in the wireless device. Moreover, the apparatus includes means for increasing the at least one system parameter in the wireless device when the when the maximum allowed periodicity is greater than the preferred tune away periodicity.
According to still another aspect, a computer program product comprising computer-readable medium is disclosed. The medium includes code for causing a computer to monitor a call paging channel from a first radio access technology received at a wireless device in a wireless communication device supporting multiple radio access technologies. Furthermore, the medium includes code for causing a computer to determine at least one system parameter received over the call paging channel, the at least one system parameter related to a maximum allowed periodicity of when the wireless device may tune away from a second radio access technology to monitor paging from the first radio access technology. The medium also includes code for causing a computer to determine whether the maximum allowed periodicity determined from the at least one system parameter is greater than a preferred tune away periodicity stored in the wireless device. Additionally, the medium includes code for causing computer to increase the at least one system parameter in the wireless device when the when the maximum allowed periodicity is greater than the preferred tune away periodicity.
The presently disclosed apparatus and methods afford better optimization of one network's data in a dual network device that is adversely affecting by tune away to another network by decreasing the tune away frequency. In particular, an SRLTE UE device may be configured to increase its in-use Slot Cycle Index (SCI) in order to decrease 1x CDMA tune away. In a further aspect, a UE or network station (e.g., an eNodeB or Base Station) may be configured to effect change of the network maximum SCI (MAX_SLOT_CYCLE_INDEX); i.e., allowing network tuning of the MAX_SLOT_CYCLE_INDEX, which allows for a reduced frequency of tune away for 1x CDMA paging. In yet a further aspect, both increase of the SCI and tuning the MAX_SLOT_CYCLE_INDEX may be utilized in conjunction to achieve even greater optimization. Additionally, it is noted that the present methods and apparatus also afford increased power savings as the UE will not tune away as frequently to check 1x CDMA paging.
For purposes of the following discussion, it is noted that the word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any example described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other examples. Additionally the terms “CDMA 1x”, “1xRTT”, and “1x” may be used interchangeably herein to denote any one of the various iteration of CDMA2000 1x standards or technologies. Furthermore, the term “LTE technology” as used herein encompasses various known technologies within 4G and includes, for example, LTE-Advanced Technology.
As illustrated, the environment 100 includes a UE 102 that is an SRLTE device operable in both LTE and CDMA 1x technologies, as illustrated by LTE portion 104 and CDMA 1x portion 106. It is noted at the outset, however, that it is conceivable that the present methods and apparatus may be applied to other types of UEs employable with other radio access technologies (RATs). That is, the presently disclosed call set up reducing and power saving methods and apparatus could be applied in other RATs where the mixed utilization of different portions of call set up procedures could afford realization of eliminating processes to reduce time, or, in the instance where one of the technologies uses an SCI or similar index, added power reduction capabilities by allowing cycling of power up of a UE to be reduced in frequency or extended in the periodicity.
The environment 100 may further include an E-UTRAN eNodeB 108 that effectuates wireless access for the UE 102 to an LTE radio access network via the LTE-Uu interface (110). The E-UTRAN 108 is in network communication with core network (CN) elements in the LTE evolved packet core (EPC) including a Mobility Management Entity (MME) 111 via an S1-MME interface 112 and Serving and PDN Gateways (S-GW/P-GW) 114 via an S1 interface (S1-U 116). According to the EPC model, MME 111 also is in communication with S-GW/P-GW 114 via an S11 interface 117. The core network is responsible for the overall control of the LTE UE and establishment of various bearers (i.e., a set of network parameters that define how UE data is treated when it travels across the network (e.g., providing a specific data rate for particular data, etc.)).
The MME 110, in particular, is the control node that processes the signaling between the UE 102 and the core network, but also processes signaling to other networks, such as a CDMA 1x network. The signaling between an LTE network and a CDMA 1x network is effectuated via an S102 tunnel or interface, as indicated in
To better optimize LTE data performance, the present disclosure includes at least two methodologies (and associated apparatus) that can be used in the context of
If the SCI_p value is less than the SCI_max value as determined at block 206, however, then flow proceeds to block 208. Here, the UE in configured to set the SCI in use (SCI_M-use) equal to the SCI_max value in order to achieve a reduced frequency of 1x CDMA tune away. In an alternative aspect, instead of immediately increasing the SCI in use value to the maximum SCI, the value could be incremented, such as in units of one or in multiple units. After the increase in the SCI value, block 210 illustrates that the UE notifies the network (e.g., the LTE network) of the UE's new SCI value via registration messaging, as one example.
In another aspect, it is noted that the methodology of
As may be seen at process block 302, method 300, which may be implemented in a network station (e.g., a base station), begins after an evaluation period, where a checking time is at the end of the evaluation period. In an example, half-hourly or hourly checking could be sufficient as a Timer Registration value is typically between ½ hour and 1 hour. It is noted that the timing is not limited to such, however, and could be more or less. Flow proceeds to block 304 where the 1xSRLTE device population, location area wise, of such devices currently registered to a BSC, such as BSC 126, is determined. The determined population is compared to a population threshold as shown in block 306. In particular, if the population is not above the threshold, no further action is taken and flow reverts to block 302. It is noted that the processes of blocks 304 and 306 could be optional according to an aspect, as these steps are predominantly directed to determining if tuning of the SCI is feasible That is, the condition holds that when the SRLTE population is greater than a threshold then changing the MAX_SCI is allowed. If the SRLTE population is less than a threshold, however, the gain that benefits the SRLTE device is not enough to offset the consequence resulting from lowering the longer paging time that would also affect non-SRLTE devices. According to another aspect, it is noted that the determination of the SRLTE population could be effected on a Registration/Origination/Page Response received with a unique Electronic Serial Number (ESN) lot (i.e., to look for 1xSRLTE capable devices) during the evaluation time. Additionally, the threshold may be expressed as a predefined percentage.
In another example, the SRLTE population could also be determined from the Mobile Equipment Identifier (MEID). The MEID can be exchanged during a call through a “Status Request Message” and a “Status Response Message” pair where the 1x network sends the “Status Request message” and the UE replies with the “Status Response Message.” It is further noted that the use of other messages or message pairs is also contemplated for querying either the ESN or MEID, and that any other message(s) may be used that are suitable for achieving the query process for determining SRLTE population.
If the number of SRTLE devices (or percentage of SRLTE devices) in the local area exceed the predetermined threshold in block 306, then flow proceeds to decision block 308. Here, a determination is made whether the maximum SCI value (SCI_max) is less than a maximum value allowed by an operator. If not, then it is known that the SCI_max is at its allowable limit and no further increase may be accomplished. In such case, flow then returns back to block 302. It is noted that in typical situations, the SCI_max will be no more than 3, but method 300 is not necessarily limited to such and could encompass using higher SCI values.
Alternatively at block 308, if the SCI_max value is less than the maximum allowable SCI, flow then proceeds to decision block 310. Decision block 310 is used to determine whether two different conditions are met, and only upon meeting both conditions (i.e., an “AND” condition), will the SCI values be increased. In particular, block 310 first checks whether the paging success over the evaluation period is greater than a predefined target success rate. Additionally, block 310 determines if a paging response time over the evaluation period is less than a target paging response time. Thus, if the paging success rate exceeds a target rate, and the response time is quick such that it is less than a target response time, then it is permissible to further increase the maximum SCI value, thus decreasing the 1x CDMA tune away frequency. As indicated in the particular example of
The methodology of
As mentioned before, the methodologies of
Although not illustrated, each RAT portion 404, 406 may include data processing used for transmitting and receiving data via the different respective RATs. It is noted, that the configuration of
In the configuration of
The processor(s) 408 may control the operations of each of portions 404 and 406, as well as modem/interface 402. In operation, the UE 400 may implement one or more of the processes or operations illustrated in
The other procedure 504 in method 500 may be implemented in a network station or other network node, such as BTS 128. The procedure 504 includes process 514 that determines in the network station whether the maximum SCI is less than a maximum allowed SCI value set in a network. If the maximum SCI is less than the maximum allowed SCI as determined in process 514, then procedure 504 includes determining a success rate for paging and a paging response time as illustrated in block 516. If the the success rate for paging is greater than a predefined target success rate and the paging response time is less than a predefined paging response target time, the maximum SCI may then be increased, as shown in block 518. To what extent or gradation the maximum SCI value is increased is variable. In one aspect the value may be increased in increments of one (1). In other aspects the value could be increased by a multiple amount, such as 2 or 3, and in another the value could be simply taken to a maximum settable value (e.g., SCI=7). After the maximum SCI value has been increased, the network station may broadcast the new maximum SCI value in a locality (e.g., a cell or sector). In an aspect the broadcast is accomplished via the SPM message over the paging channel.
Apparatus 600 includes a means or module 602 for monitoring a call paging channel received from a first radio access technology. In particular, the module 602 may effect monitoring of the SDM in the call paging channel from a 1x CDMA system. In an aspect, module 602 may include a modem or radio in a UE/MS, as well as a processing portion or processor configured for digital signal processing that effects demodulation and decoding to obtain the SDM transmitted over the call paging channel. It is noted that portions or all of such processing may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA).
Additionally, apparatus 600 includes a module 604 for determining at least one system parameter received over the call paging channel. In an aspect, the system parameter is the maximum SCI value transmitted in the SDM. Module or means 604 may be implemented by a processing portion or processor configured for digital signal processing that effects demodulation and decoding to determine the parameter from the SDM transmitted over the call paging channel. It is noted that portions or all of such processing may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA).
Apparatus 600 also includes a module 606 for determining whether the maximum allowed periodicity determined from the system parameter (e.g., the SCI_max value) is greater than a preferred tune away periodicity stored in the wireless device. In an aspect, the preferred SCI (SCI_p) is compared with the maximum SCI (SCI_max) value to determine whether it is greater. This determination shows whether the SCI value in the wireless device has room to be increased, or if it is already at the maximum. Module or means 606 may be implemented by a processing portion or processor configured for digital signal processing that effects demodulation and decoding to determine the parameter from the SDM transmitted over the call paging channel. It is noted that portions or all of such processing may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA).
Furthermore, apparatus 600 includes a module or means 608 for increasing the tune away periodicity of the wireless device (i.e., increasing the SCI value) when the maximum allowed periodicity (i.e., SCI_max) is greater than the preferred tune away periodicity (i.e., SCI_p). Module 608 may be implemented by a processing portion or processor configured for digital signal processing that effects demodulation and decoding to determine the parameter from the SDM transmitted over the call paging channel. It is noted that portions or all of such processing may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA).
In another aspect, the first radio access technology may be a 1x CDMA and a second radio access technology is LTE. In a further aspect, means 602, 604, 606, and 608 could be implemented with the assistance of processor(s) 408 in
Apparatus 700 includes a means or module 704 for determining whether a maximum SCI is less than a maximum allowed SCI value set in a network, such as an SCI maximum for a particular sector in a 1x CDMA network. In particular, the module 704 is configured for performing the determination and may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA). Additionally, apparatus 700 includes a module or means 706 for determining a success rate for paging and a paging response time if the maximum SCI is less than the maximum allowed SCI. This module or means 706 may be implemented by a processing portion or processor configured for digital signal processing that effects demodulation and decoding to determine the success rates and response times. It is noted that portions or all of such processing may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA).
Apparatus 700 also includes a module or means 708 for increasing maximum SCI when the success rate for paging is greater than a predefined target success rate and the paging response time is less than a predefined paging response target time. This increase, in turn, will allow UEs or MSs to potentially further increase the SCI values within the devices, such as through the method of
Furthermore, apparatus 700 includes a module or means 710 for broadcasting the new maximum SCI value, particularly broadcast in a paging area, such as a sector in a particular cell. It is noted that portions or all of such processing may be implemented with a specific processor, such as an Application Specific Integrated Circuit (ASIC) or a field-programmable gate array (FPGA), as well as an encoder, modulator and RF transmitter.
In another aspect, a radio technology in the base station may be 1x CDMA. In a further aspect, means 704, 706, 708, and 710 could be implemented with the assistance of processor(s) in BTS 128 and BSC 126, for example, and may also include other equivalent devices or structures for carrying out the functions or methodologies disclosed herein.
In light of the above-disclosure, those skilled in the art will appreciate that allowing either a UE/MS or a base station to increase the SCI implemented in a UE/MS will afford a decrease in the periodicity of tune away from one RAT to another RAT (e.g., tune away from LTE to 1x CDMA), thus optimizing data performance for the RAT from which the UE/MS is being tuned away. It is noted that the present methods and apparatus may be particularly suitable in some countries that deploy 1xSRLTE+G devices in which subscribers of those markets could be primarily using GSM for voice (keeping a GSM number for MT call) but LTE/EVDO for data, and where 1x CDMA voice could be secondary choice for voice. These countries typically have no mobile number portability such that subscribers have to keep using old GSM number for keeping the old connection.
It is understood that the specific order or hierarchy of steps in the processes disclosed is merely an example of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
Those of skill in the art will understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
Those of skill will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
The previous description of the disclosed examples is provided to enable any person skilled in the art to make or use the presently disclosed methods and apparatus. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
