Dual SIM Dual Standby (DSDS) wireless devices are configured with a primary subscriber identity module (SIM) card providing both voice and data connections on a primary network and a secondary SIM card for providing data-only access on a secondary network. The utilization of wireless network resources by a DSDS wireless device can be enhanced by accounting for congestion on each of the associated networks and data usage of the device to determine whether a switch between networks would be beneficial for device performance

Chinnakkannu, Jayachandran

Nayak, Shivank

Sadindran, Sooraj

English

Technical Disclosure Common

Technical Disclosure Commons Defensive Publications Series August 2020 Optimized Data Switching for Opportunistic Data DSDS Devices Shivank Nayak Sooraj Sadindran Jayachandran Chinnakkannu Follow this and additional works at: https://www.tdcommons.org/dpubs_series Recommended Citation Nayak, Shivank; Sadindran, Sooraj; and Chinnakkannu, Jayachandran, "Optimized Data Switching for Opportunistic Data DSDS Devices", Technical Disclosure Commons, (August 26, 2020) https://www.tdcommons.org/dpubs_series/3547 This work is licensed under a Creative Commons Attribution 4.0 License. This Article is brought to you for free and open access by Technical Disclosure Commons. It has been accepted for inclusion in Defensive Publications Series by an authorized administrator of Technical Disclosure Commons. OPTIMIZED DATA SWITCHING FOR OPPORTUNISTIC DATA DSDS DEVICES  Abstract Dual SIM Dual Standby (DSDS) wireless devices are configured with a primary subscriber identity module (SIM) card providing both voice and data connections on a primary network and a secondary SIM card for providing data-only access on a secondary network. The utilization of wireless network resources by a DSDS wireless device can be enhanced by accounting for congestion on each of the associated networks and data usage of the device to determine whether a switch between networks would be beneficial for device performance.  Background Wireless communication networks are widely deployed to provide various communication services such as, for example, telephony, video, data, and messaging. Some wireless devices, such as smartphones, tablet computers, and laptop computers, are configured to facilitate communication on more than one of these wireless networks as they include more than one SIM that provides a user with access to a particular wireless network for each SIM.  In a wireless device containing two SIMs and one transceiver, only one of the two subscriptions may be transmitting or receiving radio frequency (RF) signals at a time, a situation commonly referred to as Dual SIM Dual Standby (DSDS) because while one subscription is actively transmitting or receiving, the other subscription is placed on standby. For example, in a DSDS device, a user may conduct a voice call via one of the two SIMs which requires the device to tune the transceiver away from the first subscription to the second subscription to receive paging signals and to transmit, for example, message acknowledgment signals and/or measurement indication signals. Thus, while the first subscription continues an ongoing call, the transceiver may periodically tune away from the first subscription to the second subscription to receive 2Nayak et al.: Optimized Data Switching for Opportunistic Data DSDS DevicesPublished by Technical Disclosure Commons, 2020necessary paging and/or control information. As another example, when a DSDS device is downloading a data file (e.g., a music file) using the second subscription of a second SIM and receives a voice call from the network subscription of the first SIM, the data download must be discontinued until the voice call has ended. This can cause a sub-optimal user experience as activity on one, or both, of the subscriptions may be slow or intermittent.  Description  A DSDS device may be configured with two different network subscriptions accessible via a primary SIM providing both voice and data connections on a primary network and a secondary SIM for providing data only access on a secondary network.  With this configuration, data services may be accessed on either of the networks, whereas voice services may only be accessed on the primary network.  The number of devices connected to a particular network and the data usage of applications/programs running on those devices contribute to network congestion, which can reduce data transfer speeds and result in poor user experience. The wireless networks to which the primary and secondary SIMs connect may vary in spectrum efficiency, latency, and user throughput, such that it sometimes may be beneficial to switch between the networks to take advantage of one or more of these attributes on a given network.  Thus, the ability of a DSDS device to be able to switch between networks for certain services can optimize network resource utilization and improve user experience.  For example, in the opportunistic DSDS device described above having a primary SIM providing both voice and data, and a secondary SIM providing only data access, typically all data access requests are routed to the secondary SIM, regardless of whether the network associated with the secondary SIM is congested by the number of connected devices or by devices utilizing a large amount of bandwidth on the network. The result is that, though the network associated 3Defensive Publications Series, Art. 3547 [2020]https://www.tdcommons.org/dpubs_series/3547with the primary SIM may be less congested and capable of handling data transfers much quicker than the network associated with the secondary SIM, the DSDS device will automatically route all data access to the secondary SIM. To increase flexibility for DSDS devices in choosing which network to connect to for a given service, a method is described below which allows a device to detect the level of congestion on available networks and determine whether switching from a secondary SIM to a primary SIM will be beneficial and, if so, implementing the switch.    For a device employing DSDS to determine whether it is beneficial to switch from a first network to a second network, an estimated link capacity for each of the primary and secondary networks is calculated based on instantaneous link capacity using the radio transceiver of the device.  The estimated link capacity for each network is then combined with the data usage of the device to obtain a congestion ratio of data usage to link capacity for each network. Higher values of the congestion ratio indicate that there is higher data usage by the device on the associated network and/or that the network has relatively low link capacity, meaning the device is more likely to experience slower data transfer and reduced performance when utilizing the particular network.  Estimates of the link capacity and device data usage are determined over a window of time, which can be adjusted based on the desired sensitivity of the estimates. A moving average of the congestion ratio is continuously calculated for each network and maintained by the device.   The decision to switch from the secondary SIM to the primary SIM is based on a comparison of the congestion ratios for the secondary network and primary network to first and second threshold values, respectively, and a comparison of the difference between the first and second congestion ratios to a pre-defined improvement factor.  In other words, it is first determined whether the secondary network is overly congested and/or if the data usage of the 4Nayak et al.: Optimized Data Switching for Opportunistic Data DSDS DevicesPublished by Technical Disclosure Commons, 2020connected device is sufficiently high to warrant switching data service to the primary network. However, effort also is taken to ensure that the primary network is not overly congested such that switching would provide little to no benefit over remaining connected to the secondary network. Thus, the congestion ratio of the primary network is compared to a second threshold value. Where the congestion ratio of the secondary network is higher than a first threshold value, meaning that the network is likely congested relative to the amount of data being used by the device, and the congestion ratio of the primary network is lower than a second threshold value, meaning that the primary network is not likely congested relative to the amount of data being used by the device, the device then compares the difference between the congestion ratios for the primary and secondary networks and compares the difference to a pre-determined improvement factor. The improvement factor accounts for the degree of performance improvement anticipated if the device switches from the secondary network to the primary network as switching between networks comes at some cost to the system. If the difference between the congestion ratios is minimal, it is unlikely that sufficient benefit will be realized in the performance of the device if the switch is implemented, whereas a larger difference between the congestion ratios indicates that a significant increase in performance is likely if data service is switched from the secondary network to the primary network.    As illustrated in the flow chart of Figure 1 below, the device makes an initial determination as to whether a device that is connected to a primary network is also connected to a secondary network for data service. If the device is connected to the secondary network, the device estimates the link capacity for both the primary network and the secondary network. Data usage information is also obtained for the device. A ratio of the link capacity to data usage (congestion ratio) is calculated for each network. The congestion ratio of the secondary network 5Defensive Publications Series, Art. 3547 [2020]https://www.tdcommons.org/dpubs_series/3547is compared to a threshold value and, if the congestion ratio of the secondary network is less than the threshold, the device maintains data service on the secondary network. However, if it is determined that the congestion ratio is greater than the threshold value, the congestion ratio of the primary network is compared to a second threshold.  If the congestion ratio of the primary network is greater than the second threshold, no switch is initiated and data service is maintained on the secondary network. If the congestion ratio of the primary network is less than the second threshold, the difference between the congestion ratios of the primary and secondary networks is calculated and compared to a pre-defined improvement factor to determine whether a switch to the primary network would be sufficiently beneficial. If the calculated difference is greater than the improvement factor, the device switches data service to the primary network. If the calculated difference is determined to be less than the improvement factor, the device maintains data service on the secondary network.  6Nayak et al.: Optimized Data Switching for Opportunistic Data DSDS DevicesPublished by Technical Disclosure Commons, 2020IS DEVICE CONNECTED TO SECONDARY NETWORK FOR DATA SERVICE?ENDESTIMATE LINK CAPACITY OF SECONDARY NETWORKOBTAIN DATA USAGE OF DEVICECALCULATE CONGESTION RATIO OF SECONDARY NETWORKESTIMATE LINK CAPACITY OF PRIMARY NETWORKCALCULATE CONGESTION RATIO OF PRIMARY NETWORKIS CONGESTION RATIO OF SECONDARY NETWORK > FIRST THRESHOLD?IS CONGESTION RATIO OF PRIMARY NETWORK < SECOND THRESHOLD?MAINTAIN DATA SERVICE CONNECTION ON SECONDARY NETWORKSWITCH DATA SERVICE TO PRIMARY NETWORKNOYESYESNONOCALCULATE DIFFERENCE BETWEEN CONGESTION RATIOSIS DIFFERENCE > IMPROVEMENT FACTOR?YESYESNO Figure 1  The above-described method assumes the primary SIM is active and not in idle or standby mode. In the event that the primary SIM of a device is in idle mode, the link capacity of the primary network can be estimated using past link capacity estimates for given signal or radio parameters of the primary SIM. Where a past link capacity is not available for the primary SIM, 7Defensive Publications Series, Art. 3547 [2020]https://www.tdcommons.org/dpubs_series/3547once a determination that the congestion ratio for the secondary network has reached or exceeded the preset threshold, the device can determine whether the signal strength and quality of the primary network are above defined thresholds and, if so, can implement switching data service to the primary network.   Independent of the method by which a switch is initiated, once data service has been switched from the secondary network to the primary network, validation of the switch is performed by calculating the actual congestion ratio of the primary network and, if the actual congestion ratio is found to be higher than the estimated congestion ratio used by the device, the device will switch data service back to the secondary network. Signal condition, mobility, and time duration can be used to provide hysteresis within the system to avoid multiple instances of switching between networks in the event of a failed attempt to switch.   References 1. U.S. Patent Application Pub. No. 20160353449 (filed May 29, 2015), incorporated herein by reference in its entirety. 2. U.S. Patent Application Pub. No. 20170280380 (filed March 26, 2016), incorporated herein by reference in its entirety. 3. U.S. Patent Application Pub. No. 20150237497 (filed Feb. 19, 2014), incorporated herein by reference in its entirety.  4. International Patent Application Pub. No. WO2017166678 (filed Aug. 30, 2016), incorporated herein by reference in its entirety.  8Nayak et al.: Optimized Data Switching for Opportunistic Data DSDS DevicesPublished by Technical Disclosure Commons, 2020

Optimized Data Switching for Opportunistic Data DSDS Devices

https://www.tdcommons.org/cgi/viewcontent.cgi?article=4626&context=dpubs_series

Optimized Data Switching for Opportunistic Data DSDS Devices

Abstract

Similar works

Full text

Available Versions

Technical Disclosure Common