Certain user equipment devices and chipsets support multi-subscriber identity module (SIM) cards. Such devices are equipped with multiple SIM card slots, and each SIM card may be associated with a respective cellular communications service and service provider. Further, certain multi-SIM capability devices support wireless communication over different types of cellular access stations, such as macro cells, small cells, micro cells, etc. Generally, the communications range for a base station macro cell may be between 20-25 miles, with small cells and micro cells providing smaller coverage areas.
For a more complete understanding of the embodiments and the advantages thereof, reference is now made to the following description, in conjunction with the accompanying figures briefly described as follows:
The drawings illustrate only example embodiments and are therefore not to be considered limiting of the scope described herein, as other equally effective embodiments are within the scope and spirit of this disclosure. The elements and features shown in the drawings are not necessarily drawn to scale, emphasis instead being placed upon clearly illustrating the principles of the embodiments. Additionally, certain dimensions or positions of elements and features may be exaggerated to help visually convey certain principles. In the drawings, similar reference numerals between figures designate like or corresponding, but not necessarily the same, elements.
In the following paragraphs, various embodiments are described in further detail by way of example with reference to the attached drawings. In the description, well known components, methods, and/or processing techniques are omitted or briefly described so as not to obscure the embodiments.
As outlined above, multi-SIM capable user equipment (UE) devices support wireless communication with multiple cellular services and/or service providers. Further, these UE devices may support wireless communication with different types of cellular access stations, such as macro cells, small cells, micro cells, etc. In this case, the UE devices should be optimized to perform communication link handoffs among macro cells and small cells, for example, for the supported cellular services and service providers.
In this context, aspects of the embodiments described herein are related to improvements in the accuracy of proximity detection for small cells, even in the presence of parameter changes in communications networks. Further, in the context of UE devices which operate in dual SIM dual standby (DSDS) mode, improvements in proximity detection for suspended modems using measurements from active modems are described. Additionally, according to the features of the embodiments described herein, one or more modems in a multi-SIM capable UE device may be able to establish communications with a small cell using less energy and time, and resume communications with one or more macro cells or small cells more quickly after resuming from a suspended mode.
Turning now to the drawings, a description of exemplary embodiments of systems and system elements are provided, followed by a discussion of the operation of the same.
It should be appreciated that the first communications service may be embodied by a network of macro cells, including the macro cell 112 and other macro cells, which embody an access neighborhood of the first communications service. Similarly, the second communications service may be embodied by a network of macro cells, including the macro cell 114 and other macro cells, which embody an access neighborhood of the second communications service.
The small cell 116 may be embodied as a cellular access point that provides a coverage area smaller than that of a macro cell (e.g., either the macro cells 112 or 114). The coverage area may be smaller in terms of geographic coverage and/or the number of UE devices which may be supported by the small cell 116, for example. The small cell 116 may be relied upon to extend the reach or bolster the coverage area of the first communications service. For example, the small cell 116 may be installed indoors, such as in a house, an office building, a warehouse, or in a shopping mall, where the coverage provided by the macro cell 112 may be intermittent. Similarly, the small cell 116 may be installed at sporting venues, transportation terminals, or theme parks, for example, where the coverage provided by the macro cell 112 may be overloaded. As described herein, small cells may encompass femtocells, picocells, microcells, and other related types of access points. Such small cells may provide radio coverage footprints ranging from 10 meters for in-building installations to 2 kilometers for rural installations, for example. In some cases, a small cell may be embodied as a closed subscriber group (CSG) access point. In this case, access to the communications service provided by the CSG may be limited to certain users, groups of users, or based on other parameters.
The macro cells 112 and 114 may broadcast control channels which are used by the UE device 100 to establish communication links with the macro cells 112 and 114 and, respectively, the first and second communications services. The control channels may include broadcast control channels (BCCHs), for example, which identify and describe the configuration and available features of the macro cells 112 and 114. The control channels may also provide a list of base station identification codes (BSICs), Primary Scrambling Codes (PSCs) and/or Physical Cell IDs (PCIDs), as well as corresponding channel numbers associated with neighboring (i.e., geographically adjacent or proximate) base stations or macro cells. That is, the control channels may be relied upon by the UE device 100 to retrieve a neighbor cell list including BSICs/PSCs/PCIDs and radio frequency (RF) channel numbers (RFCNs) used by neighboring macro cells. In this context, the macro cells 112 and 114 may maintain and broadcast a BCCH Allocation List (i.e., BA list) including a list of frequencies of neighboring cells. The BA list may be relied upon by the UE device 100 to estimate signal strength and/or signal quality measurements for channels available on neighboring macro cells, and to determine when to reselect, handover, or handoff a communications link to a neighboring macro cell.
It is noted that, although neighbor cell lists may include lists of BSICs/PCIDs/PSCs and RFCNs used by macro cells neighboring the macro cells 112 and 114, the neighbor lists may not identify the small cell 116 or the RF channel(s) associated with the small cell 116. In other words, even if the small cell 116 is positioned within or proximate to the coverage area 122 of the macro cell 112, the neighbor cell list provided by the macro cell 112 may not identify the small cell 116 as a neighboring cell. In this context, it is noted that, although the UE device 100 may rely on neighbor cell lists to establish and/or handoff communications links among neighboring macro cells, the UE device 100 may need to rely upon other means to identify small cells available for establishing communications links. Because the UE device 100 in
According to aspects and features of the embodiments described herein, the search for and detection of small cells by the UE device 100 may be improved through a combination of fingerprinting and proximity detection algorithms that gather and review positioning data. For example, certain positioning data may be gathered and stored as a fingerprint for the small cell 116, when the UE device 100 establishes a communication link with the small cell 116. Subsequently, positioning data which is gathered by the UE device 100 over time may be compared with attributes of the fingerprint for the small cell 116, to detect proximity to the small cell 116. In various embodiments, the positioning data may include global navigation satellite system (GNSS), Wi-Fi (i.e., 802.11) signal strength levels and network identifiers, and access neighborhood measurement data, for example. In the embodiments described herein, because the UE device 100 is embodied as a multi-SIM capable UE device, the UE device 100 may gather neighborhood measurement data for one or more communications services. As further described below with reference to
The UE device 100 may determine proximity to one of the small cells 231 or 232 based on a proximity detection algorithm. As described above, proximity detection algorithms may rely on positioning data, such as GNSS, Wi-Fi signal strength levels and network identifiers, and radio access network (RAN) measurement data, for example. Of these types of data, it is noted that the UE device 100 may gather access neighborhood measurements as part of standard cellular protocols and procedures. In this sense, it is not necessary for a UE device to expend additional power to gather access neighborhood measurements. On the other hand, GNSS and Wi-Fi services, as incorporated in the UE device 100, may be enabled only when necessary and, in general, require additional power consumption. Thus, for low power consumption, for example, access neighborhood measurements are relied upon in the embodiments described herein for proximity detection and fingerprinting.
Access neighborhood measurements may be used to triangulate the position of the UE device 100 in the network deployment 20 and, when the UE device 100 establishes a communication link with one of the small cells 231 or 232, the triangulation measurements may be stored in the UE device 100 as a fingerprint for the small cell. In turn, the next time that the UE device 100 encounters a similar triangulation measurement, the UE device 100 may assume that it is within a certain proximity to the small cell. However, triangulation measurements may not be particularly helpful for every small cell, depending upon coverage of the network deployment 20. For example, as illustrated in
Thus, in the case of the network deployment 20, the UE device 100 may seek to improve the proximity detection afforded by access neighborhood measurements by using additional positioning data, such as GNSS and/or Wi-Fi positioning data, for example. Additionally or alternatively, the UE device 100 may perform periodic searches for small cells in an effort to identify them. Gathering such additional positioning data and performing periodic small cell searches, however, impacts power usage and may interfere with other operations of the UE device 100. In the context of these examples, it is noted that, if access neighborhood measurements are introduced from a second communications network and/or service, then the UE device 100 can increase the accuracy of its proximity detection algorithms with additional access neighborhood measurements.
Because the UE device 100 is embodied as a multi-SIM capable UE device, the UE device 100 may establish one or more communication links with the macro cells 311-314, 341, and 342, and the small cells 331 and 332. Particularly, the UE device 100 may establish a first communication link with one of the macro cells 311-314 or the small cells 331 and 332 using the first SIM card 102, and establish a second communication link with the macro cells 341 and 342 using the second SIM card 104. Further, the UE device 100 may gather access neighborhood measurements for both the network deployments of the first communications service (e.g., the macro cells 311-314) and the second communications service (e.g., the macro cells 341 and 342).
For example, access neighborhood measurements for both the first and second communications services may be used in combination to triangulate the position of the UE device 100 and, when the UE device 100 establishes a communication link with a small cell, the combined triangulation measurements may be incorporated into a fingerprint for the small cell. In turn, the next time in which the UE device 100 encounters a similar triangulation measurement, the UE device may assume that it is within a certain proximity to the small cell.
As compared to the examples in
The front end 410 may be embodied as one or more general- or specific-purpose processors or processing circuits, one or more analog-to-digital converter (ADC) circuits, digital-to-analog converter (DAC) circuits, amplifiers, filters, etc., for a physical layer front end chain of a cellular communications radio. The first modem 420 includes a protocol stack 422 and the first SIM 102, and the second modem 430 includes a protocol stack 432 and the second SIM 104. Generally, the first and second modems 420 and 430 are configured to modulate and demodulate data upon carriers for transmission and reception via the front end 410, and may support telephony and other data transfer between the UE device 100 and first and second communications services. The protocol stacks 422 and 432 may supervise, implement, and control the protocol requirements for the first and second communications services, to ensure suitable data transfer by the UE device 100 over the first and second communications services. The first and second modems 420 and 430 may be embodied as one or more general- or specific-purpose processors or processing circuits.
It is noted that some UE devices, such as the UE device 100, include one RF front end chain for the modems 420 and 430. In the embodiment of the UE device 100 illustrated in
In DSDS mode, both of the modems 420 and 430 of the UE device 100 may standby for incoming calls from respective service providers. Once a call is established, however, the UE device 100 suspends one of the modems 420 and 430 while the other is active. In the DSDS configuration illustrated in
The fingerprint controller 440 receives access neighborhood measurements for various communications services. For example, in the dual SIM capable UE 100, the fingerprint controller 440 may receive access neighborhood measurements associated with a first communications service from the first modem 420 and receive access neighborhood measurements associated with a second communications service from the second modem 430. With reference to the network deployment 30 of
For the dual SIM capable UE 100, the fingerprint generator 442 generates fingerprints associated with small cells, such as the small cells 331 and 332 (
The proximity detector 444 detects proximity to small cells by comparing access neighborhood measurements for first and second communications services with corresponding fingerprints for small cells. In other words, once a fingerprint for a small cell is generated by the fingerprint generator 440, this fingerprint may be relied upon by the proximity detector 444 to determine whether the UE device 100 is within a certain proximity to the small cell. The UE device 100 may then set up, establish, or handoff a communication link with the small cell. The detection of proximity by the proximity detector 444 is described in further detail below with reference to
Before turning to the process diagrams of
At reference numeral 503, the process includes measuring an access neighborhood of the first communications service. For example, the UE device 100 may receive a BA list for the neighborhood of macro cells associated with the first communications service from a control channel of the macro cell 314. Using this BA list, the UE device 100 may identify one or more of the macro cells 311-313 (or other macro cells) as being neighbors of the macro cell 314. In turn, using the front end 410 and/or the modem 420, the UE device 100 may take signal strength, power, time of arrival, or other measurements in connection with the frequency channels supported by the macro cells 311-313. These measurements (e.g., m1, m2, m3, . . . , etc.) may be provided to the fingerprint controller 440 of the UE device 100. It is noted that, depending upon the number of neighboring macro cells in the neighborhood of the macro cell 314, for example, the number of measurements may vary.
At reference numeral 504, the process includes measuring an access neighborhood of the second communications service. For example, the UE device 100 may receive a BA list for the neighborhood of macro cells associated with the second communications service from a control channel of the macro cell 341. Using this BA list, the UE device 100 may identify the macro cell 342 (or other macro cells) as being neighbors of the macro cell 341. In turn, using the front end 410 and/or the modem 430, the UE device 100 may take signal strength, power, time of arrival, or other measurements in connection with the frequency channels supported over the macro cell 342. These measurements (e.g., n1, n2, . . . , etc.) may be provided to the fingerprint controller 440 of the UE device 100. It is noted that, depending upon the number of neighboring macro cells in the neighborhood of the macro cell 342, for example, the number of measurements may vary.
At reference numeral 505, the process includes manually selecting a small cell. Here, a user of the UE device 100 may instruct the UE device 100 to perform a manual search for small cells. This search may identify the small cell 331 (
At reference numeral 506, the process includes generating a fingerprint for a small cell for the first communications service based on the access neighborhood of the first communications service and the access neighborhood of the second communications service. For example, the fingerprint generator 444 of the fingerprint controller 440 may generate and store a fingerprint for the small cell 331 based on the access neighborhood measurements of the first communications service (e.g., m1, m2, m3, . . . , etc.) and the access neighborhood of the second communications service (e.g., n1, n2, . . . , etc.). In certain embodiments, the fingerprint for the small cell 331 may also include positioning data attributes such as global navigation satellite system (GNSS) data and/or Wi-Fi (i.e., 802.11) signal strength levels and network identifiers, for example.
Once a fingerprint is generated, it is stored for later use by the fingerprint controller 440. For example, the fingerprints include attributes which may be relied upon by the proximity detector 444 to ascertain a level of confidence in whether the UE device 100 is within a certain proximity to one or more small cells. Thus, as the UE device 100 moves geographically, the proximity detector 444 of the fingerprint controller 440 may be able to identify when the UE device 100 is proximate to the small cell 331, for example, without user intervention being required. In other words, the UE device 100 may establish a communication link with the small cell 331 based on a proximity control signal from the fingerprint controller 440, without the need for a manual search for and/or selection of the small cell 331 by a user. Further, the communication link may be established with the small cell 331 without the need for the additional power and time requirements for a manual search and/or selection.
It is noted that, in various embodiments, the fingerprint controller 440 may generate and store one or more fingerprints for each small cell. Further, the one or more fingerprints for any given small cell may be adjusted or updated over time, for example, such as each time the UE device 100 establishes a communication link with the small cell. In this context, the one or more fingerprints may include statistical averages of measurements taken over time. In some cases, fingerprints may be replaced or deleted, as needed, depending upon changes in network topologies.
It should be appreciated that the modems 420 and 430 may routinely provide measurements on access neighborhoods over time. The measurements may be taken periodically, for example, or according to a certain schedule, operating parameters, or considerations. Further, the proximity detector 444 may routinely detect for proximity with small cells periodically, for example, or according to a certain schedule, operating parameters, or considerations. Thus, even if, at reference numeral 605, the proximity detector 444 does not detect proximity to a small cell, the process of proximity detection using fingerprints may continue.
Referring again to
As illustrated in
In turn, at reference numeral 609, the modem 420 performs the autonomous (i.e., non-manual, automatically-prompted, etc.) search for the small cell identified by the fingerprint controller 440. Upon verifying the identity and proximity to the small cell, the modem 420 sets up, establishes, or hands off a communication link with the small cell at reference numeral 610. That is, depending upon the present operating needs and conditions of the UE device 100, the modem 420 may set up a communication link with the small cell (e.g., discover and negotiate operating parameters, configure the protocol stack, configure filters, etc.), establish the communication link (e.g., commence data communications), and/or hand off a communication link (e.g., transition the link from a macro cell to the small cell).
Generally, according to aspects of the process of proximity detection using fingerprints, power may be conserved in a UE device. Further, the UE device may operate more seamlessly to establish communication links with small cells, without the need for user intervention. The accuracy and confidence in proximity detection is aided based on the availability of access neighborhood measurements from different communications services and/or service providers.
At the outset in
In this case, although the second modem 430 is suspended, because the fingerprint controller 440 has generated and stored fingerprints including measurement attributes for both the first and second communications services, proximity to a small cell for one of the services may be detected even if a modem associated with that service is suspended. That is, using the fingerprints described herein, proximity to a small cell for one communications service may be detected based on access neighborhood measurements for another communications service.
At reference numeral 702, because proximity to a small cell for the second communications service is detected, the process includes prompting a search for the small cell. For example, at reference numeral 702, the fingerprint controller 440 provides an identifier of the small cell to the modem 430, and prompts the modem 430 to perform an autonomous search for the small cell. In turn, at reference numeral 703, the process includes requesting admission to operate an RF front end. For example, the second modem 430 may request admission to operate the RF front end 410 from the modem controller 450.
In response to the request at reference numeral 703, at reference numeral 704, the process includes requesting the first modem to suspend operation. For example, the modem controller 450 may request the modem 420 to enter a suspended state. At reference numeral 705, the modem 420 may enter the suspended state and, at reference numeral 706, the modem 420 may confirm the suspended state with the modem controller 450. At reference numeral 707, the modem controller 450 may confirm the admission of the second modem 430 to operate the RF front end 410.
In turn, at reference numeral 708, the modem 430 performs the autonomous search for the small cell identified by the fingerprint controller 440 at reference numeral 702. Upon verifying the identity and proximity to the small cell, the modem 430 sets up, establishes, or hands off a communication link with the small cell at reference numeral 709. Again, depending upon the present operating needs and conditions of the UE device 100, the modem 430 may set up a communication link with the small cell (e.g., discover and negotiate operating parameters, configure the protocol stack, configure filters, etc.), establish the communication link (e.g., commence data communications), and/or hand off a communication link (e.g., transition the link from a macro cell to the small cell). In one embodiment, after setting up the communication link with the small cell at reference numeral 709, the modem 430 is camped on the small cell.
At reference numeral 710, the process includes releasing the RF front end. That is, the modem 430 indicates to the modem controller 450 that the RF front end 410 is being released. In turn, at reference numeral 711, the process includes requesting the first modem to resume operation with the RF front end. Further, at reference numeral 712, the process includes resuming operation of the RF front end by the first modem, and confirming the resumed operation at reference numeral 713. In the context of the UE device 100, the first modem 420 may resume operation of the RF front end 410 at reference numeral 712, and confirm the resumed operation with the modem controller 450 at reference numeral 713. In one embodiment, after resuming the operation of the RF front end 410 at reference numeral 713, the modem 430 may be camped on a macro cell.
At reference numeral 802, because proximity to a small cell for the second communications service is detected, the process includes prompting a search for the small cell. For example, at reference numeral 802, the fingerprint controller 440 provides an identifier of the small cell to the modem 430, and prompts the modem 430 to perform an autonomous search for the small cell. In turn, at reference numeral 803, the process includes requesting admission to operate an RF front end. For example, the second modem 430 may request admission to operate the RF front end 410 from the modem controller 450.
In response to the request at reference numeral 803, at reference numeral 804, the process includes rejecting admission to operate the RF front end. In this case, if the first modem is busy with the RF front end, and the RF front end cannot be suitably released without negatively impacting the operation of the UE device 100, the modem controller 450 will reject the request for admission by the second modem 430. After some time, however, the process includes the first modem releasing the RF front end at reference numeral 805. In turn, the process includes requesting the second modem to resume operation of the RF front end at reference numeral 806. That is, after the first modem 420 concludes the necessary operations with the RF front end 410, the first modem 420 releases the RF front end 410. Then, the modem controller 450 may request the modem 430 to resume operations with the RF front end 410, and the modem 430 may confirm at reference numeral 807.
At reference numeral 808, the process includes verifying proximity to the small cell. Here, it is noted that, because a significant amount of time may have elapsed since the detection of proximity with the small cell at reference numeral 802, the modem 430 seeks to confirm with the fingerprint controller 440 that the proximity is still valid. In other words, the modem 430 seeks to confirm that the UE device 100 is still located close to the small cell.
In one case, if the proximity is confirmed by the fingerprint controller 440, the fingerprint controller 440 returns a verification of the proximity at reference numeral 810. In turn, at reference numeral 811, the modem 430 performs an autonomous search for the small cell identified by the fingerprint controller 440 at reference numeral 802 and sets up, establishes, or hands off a communication link with the small cell at reference numeral 811. In one embodiment, after setting up the communication link with the small cell at reference numeral 811, the modem 430 is camped on the small cell. In an alternative case, if the proximity is not confirmed by the fingerprint controller 440, the fingerprint controller 440 invalidates the proximity at reference numeral 812. In this case, the modem 430 may remain camped on a macro cell, for example.
According to the process illustrated in
In other aspects of the embodiments, fingerprints may be used to assist with faster and more seamless transitions between macro cells. In this context,
At reference numeral 901, the process includes measuring an access neighborhood of a first communications service, which may be a service associated with the first modem 420. At reference numeral 902, the process includes detecting proximity to a small cell for the first communications service. At reference numeral 902, the detecting proximity may include comparing the access neighborhood of the first communications service (e.g., as measured at reference numeral 901) with fingerprints for small cells. At reference numeral 902, because proximity to a small cell for the second communications service is detected, the process includes prompting a search for the small cell. For example, at reference numeral 903, the fingerprint controller 440 provides an identifier of the small cell to the modem 420, and prompts the modem 420 to search for and select the small cell. In this case, after selecting the small cell at reference numeral 903, the modem 420 is camped on the small cell.
At reference numeral 904, the process includes releasing the RF front end. That is, the modem 420 indicates to the modem controller 450 that the RF front end 410 is being released. In turn, at reference numeral 905, the process includes requesting the second modem to resume operation with the RF front end, and, at reference numeral 906, the process includes confirming the resumed operation. In the context of the UE device 100, the second modem 430 may resume operation of the RF front end 410 at reference numeral 905, and confirm the resumed operation with the modem controller 450 at reference numeral 906.
In one embodiment, after resuming the operation of the RF front end 410 at reference numeral 905, the modem 430 may need to set up or establish a communication link with a new macro cell, for example, if the UE device 100 has repositioned geographically to a location outside the service area of the macro cell A. Thus, at reference numeral 907, the process includes validating proximity information. Here, a reference numeral 908, the modem 430 may seek to validate and/or retrieve positional data associated with the small cell proximity identified at reference numeral 902. In other words, the modem 430 seeks to confirm that the UE device 100 is still located close to the small cell identified at reference numeral 902.
In one case, if the proximity is confirmed by the fingerprint controller 440, the fingerprint controller 440 returns a verification of the proximity at reference numeral 909. The verification may be accompanied by positional information from a fingerprint associated with the small cell detected at reference numeral 902. As described herein, because small cell fingerprints include access network and other positional data associated with various communications services, the fingerprints may be used as a type of reverse lookup table among the modems 420 and 420. For example, at reference numeral 909, the fingerprint controller 440 may return BA list information (e.g., macro cell frequency channel information) for the second communications service, as it is associated with the location of the small cell detected at reference numeral 902. This BA information may be used by the modem 430, at reference numeral 910, to select a new macro cell (i.e., macro cell B). In this case, it is not necessary for the modem 430 to conduct a new search of the access neighborhood for the second communications service. In an alternative case, if verification of the proximity is not confirmed by the fingerprint controller 440, the fingerprint controller 440 invalidates the proximity at reference numeral 911. In this case, the modem 430 may need to conduct a new search of the access neighborhood for the second communications service and select a new macro cell (i.e., macro cell C) based on the search at reference numeral 912.
At reference numeral 1002, the process 1000 includes receiving measurements from first and second modems. For example, the measurements may be similar to the measurements m1, m2, m3, . . . , etc. and n1, n2, . . . , etc. described above with reference to
If, at reference 1006, the process determines that the measurements from the second modem do not substantially match corresponding access neighborhood attributes in the fingerprint for the small cell, then the process proceeds to reference numeral 1010, where the process determines whether the measurements from the second modem partially match those from the fingerprint. If the measurements from the second modem partially match those from the fingerprint at reference numeral 1010, then the process proceeds to reference numeral 1012, where the degree of confidence in proximity to the small cell is determined to be medium. In other words, at reference numeral 1012, the fingerprint controller 440 has detected proximity to the small cell with a medium degree of confidence. Alternatively, if the measurements from the second modem do not match those from the fingerprint at reference numeral 1010, then the process proceeds to reference numeral 1014, where the degree of confidence in proximity to the small cell is determined to be low.
In this case, where a good match was confirmed with the measurements from the first modem but the match was not confirmed with the measurements from the second modem, the fingerprint controller 440 may identify that system parameters for the second communications service, which is associated with the second modem, have changed. The change may be due to network configuration changes, for example, made by the service operator or provider of the second communications service. Here, the fingerprint controller 440 may update or replace the fingerprint to reflect the potential for changes in the network configuration.
Referring back to
If, at reference 1018, the process determines that the measurements from the second modem do not substantially match corresponding access neighborhood attributes in the fingerprint for the small cell, then the process proceeds to reference numeral 1022, where the process determines whether the measurements from the second modem partially match those from the fingerprint. If the measurements from the second modem partially match those from the fingerprint at reference numeral 1022, then the process proceeds to reference numeral 1024, where the degree of confidence in proximity to the small cell is determined to be low. In other words, at reference numeral 1024, the fingerprint controller 440 has not detected proximity to the small cell with confidence. Alternatively, if the measurements from the second modem do not match those from the fingerprint at reference numeral 1022, then the process proceeds to reference numeral 1026, where the degree of confidence in proximity to the small cell is determined to be very low.
If, at reference 1016, the process determines that the measurements from the first modem do not partially match corresponding access neighborhood attributes in the fingerprint for the small cell, then the process proceeds to reference numeral 1028, where the process determines whether the measurements from the second modem match corresponding ones from the fingerprint. If the measurements from the second modem match those from the fingerprint at reference numeral 1028, then the process proceeds to reference numeral 1030, where the degree of confidence in proximity to the small cell is determined to be medium. In this case, where a good match was confirmed with the measurements from the second modem but the match was not confirmed with the measurements from the first modem, the fingerprint controller 440 may identify that system parameters for the first communications service, which is associated with the first modem, have changed. The change may be due to network configuration changes, for example, made by the service operator or provider of the first communications service. Here, the fingerprint controller 440 may update or replace the fingerprint to reflect the potential for changes in the network configuration.
If, at reference 1028, the process determines that the measurements from the second modem do not substantially match corresponding access neighborhood attributes in the fingerprint for the small cell, then the process proceeds to reference numeral 1032, where the process determines whether the measurements from the second modem partially match those from the fingerprint. If the measurements from the second modem partially match those from the fingerprint at reference numeral 1032, then the process proceeds to reference numeral 1034, where the degree of confidence in proximity to the small cell is determined to be low. In other words, at reference numeral 1034, the fingerprint controller 440 has not detected proximity to the small cell with confidence. Alternatively, if the measurements from the second modem do not match those from the fingerprint at reference numeral 1032, then the process proceeds to reference numeral 1036, where the degree of confidence in proximity to the small cell is determined to be very low.
It is noted that the process 1000 of calculating confidence in proximity using fingerprints, as illustrated in
In other aspects of the embodiments, it is noted that the UE device 100 may perform periodic searches for small cells which are not associated with fingerprints. Further, the UE 100 may perform periodic searches for small cells which are associated with fingerprints, depending upon the level of accuracy in the proximity detection algorithms performed by the proximity detector 444. In this context, a periodic search is likely to involve a full band scan including a read of necessary system information from small cells which are identified, to decide whether the small cells are valid members of certain closed groups, for example.
Typically, this search would be done using both the modems 420 and 430, for the respective small cells or closed subscriber group cells of each. For example, a search performed by the modem 420 may identify small cells associated with the modem 430, but ignore those small cells, because they does not match subscriber information for the first service associated with the modem 420. Thus, each periodic search may be a power intensive and slow operation. According to aspects of the embodiments described herein, a single or combined small cell (or macro cell) search may be performed for both of the modems 420 and 430 by either one of the modems 420 and 430.
Similar to a periodic search, a user or manually triggered small cell search requires a full scan combined with necessary small cell readings. Such searches can also benefit from combining the results found in a scan conducted by the modem 420 and sharing the results with the modem 430, especially if a manual search on the modem 430 is to be conducted immediately afterwards. The results of a manual scan on one modem may be cached in the UE device 100 for a limited time, so that a full scan by the second modem can be avoided if the delay between the two scans in limited.
As noted above, unlike DSDS mode UE devices, DSDA mode UE devices have two independent RF front end chains. In this case, if a first modem is active and busy while a second modem is idle, the second modem may be able to improve or update proximity detection data by performing additional measurements, if the first modem finds a low level proximity match for a fingerprinted small cell. Here, it is noted that, while the first modem is active and busy, it is difficult for the first modem to perform non-scheduled measurements to improve proximity detection confidence without affecting an ongoing call, for example. However, as the second modem is idle, the capability of second modem can be used to gather additional measurements and improve proximity detection for the first modem without any impact on the ongoing call of the first modem.
In other aspects, it is noted that handoffs to CSG cells (and other small cells) during dedicated connections (e.g., UMTS Cell DCH state) are controlled by the network as part of a multi-stage process. When a UE device detects it is in proximity to a fingerprinted CSG cell, it may report this to the network via protocol signaling. This proximity detection may be more or less accurate depending on the available measurements used to determine proximity. The network then requests measurements on the target CSG cell, which may involve configuring the UE device with a gap pattern during which it is able to perform measurements to impact peak data throughput rates for an on-going data call. However, in case of poor proximity (e.g., stemming from poor proximity detection) to the CSG cell, the UE device may perform measurements on the CSG cell for an extended period before the UE device is actually close enough for the handoff.
When the network determines that the CSG cell strength meets the criteria for handoff, it will also require the UE device to acquire system information on the target CSG cell to confirm the cell identity. This acquisition of system information on the target CSG cell is performed during autonomous gaps generated by the UE device. Autonomously generated gaps will impact any on-going data transfer and, in the case of a UMTS circuit switched voice call, may cause drop-out of the audio in the source cell while system information is being acquired in the target CSG cell. Thus, this cell identity acquisition may occur several times without the UE device actually finding the target CSG cell unless proximity detection is very accurate.
To address these issues, aspects of the embodiments described herein may include certain processes to assist with handoffs to CSG and other small cells. For example, while a first modem is active and second modem is idle and after a loose proximity is detected but before the UE device indicates this to the network, the UE device may use the second RF front end associated with the second modem to attempt to measure system information on the CSG cell. Only once the target CSG cell is measured (above a set threshold) should the network be informed of proximity, thereby minimizing the time during which measurement gaps would be configured by the network.
In another case, while a first modem is active and second modem is idle, when the network requests the UE device to acquire system information, instead of autonomously creating gaps in which to read system information on the target CSG cell, the UE device may make use of the second modem to read the system information in the target cell, thereby avoiding any interruption in operation on the active modem.
In various embodiments, the processor 1110 may be embodied as a general purpose arithmetic processor, a state machine, an ASIC, or a field programmable gate array (FPGA), for example, among other processing circuits. The processor 1110 may include one or more circuits, one or more microprocessors, ASICs, dedicated hardware, or any combination thereof. In certain aspects and embodiments, the processor 1110 is configured to execute one or more software modules which may be stored, for example, on the memory device 1140. In certain embodiments, the processes illustrated in
The RAM 1120 may include or be embodied as any random access and read only memory devices that store computer-readable instructions to be executed by the processor 1110. The memory device 1140 stores computer-readable instructions thereon that, when executed by the processor 1110, direct the processor 1110 to execute various aspects of the embodiments described herein.
As a non-limiting example group, the memory device 1140 may include one or more non-transitory memory devices, such as an optical disc, a magnetic disc, a semiconductor memory (i.e., a semiconductor, floating gate, or similar flash based memory), a magnetic tape memory, a removable memory, combinations thereof, or any other known non-transitory memory device or means for storing computer-readable instructions. The I/O interface 1130 includes device input and output interfaces, such as keyboard, pointing device, display, communication, and/or other interfaces. The one or more local interfaces 1102 electrically and communicatively couple the processor 1110, the RAM 1120, I/O interface 1130, and the memory device 1140, so that data and instructions may be communicated among them.
In certain aspects, the processor 1110 is configured to retrieve computer-readable instructions and data stored on the memory device 1140 and/or other storage means, and copy the computer-readable instructions to the RAM 1120 for execution. The processor 1110 is further configured to execute the computer-readable instructions to implement various aspects and features of the embodiments described herein. For example, the processor 1110 may be adapted or configured to execute the processes described illustrated in
The flowchart or process diagrams of
Although embodiments have been described herein in detail, the descriptions are by way of example. The features of the embodiments described herein are representative and, in alternative embodiments, certain features and elements may be added or omitted. Additionally, modifications to aspects of the embodiments described herein may be made by those skilled in the art without departing from the spirit and scope of the present invention defined in the following claims, the scope of which are to be accorded the broadest interpretation so as to encompass modifications and equivalent structures.
This application claims the benefit of U.S. Provisional Application No. 61/902,609, filed Nov. 11, 2013, the entire contents of which is hereby incorporated herein by reference.
Number | Date | Country | |
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61902609 | Nov 2013 | US |