Device and method for optimized handovers

A device and method performs a handover. The method includes establishing a connection to a cellular network. The method includes determining whether a WiFi network is available for connection. The method includes determining performance data of the WiFi network based upon network metrics. The method includes determining a quality of service (QoS) parameter associated with a currently executed application, the QoS parameter being indicative of whether a handover from the cellular network to the WiFi network is permitted. The method includes performing the handover from the cellular network to the WiFi network when the performance data of the WiFi network satisfies a set of predetermined criteria for the network metrics and the QoS parameter indicates the handover is permitted.

BACKGROUND

A station may be configured to establish a connection with a wireless network. The wireless network may include a cellular network and a WiFi network. Currently, no standard exists for a handover from a cellular network to a WiFi network, particularly for a handover from a WiFi network to a cellular network to offload data as no determinations are made or used as to whether a handover should be performed to switch a connection from the cellular network to a connection with the WiFi network (or vice versa). A conventional manner entails automatically performing a handover whenever a WiFi network is available. However, there may be times when a cellular network outperforms a WiFi network (e.g., advances in cellular technology, high traffic on the WiFi network, etc.). Therefore, a connection to the cellular network may be more optimal than a connection to a WiFi network. As the conventional station will always select the WiFi network over the cellular network, a suboptimal experience may exist when the WiFi network is incapable of providing the necessary capabilities over the cellular network. Furthermore, even after being connected to the WiFi network, conditions may change such that the cellular network will now provide a more optimal experience. Thus, there is a need to determine when a handover between cellular networks and WiFi networks should be performed.

DETAILED DESCRIPTION

The exemplary embodiments relate to a device and method for performing a handover. The method comprises establishing, by a station, a connection to a cellular network; determining, by a processor of the station, whether a WiFi network is available for connection; determining, by the processor, performance data of the WiFi network based upon network metrics; determining, by the processor, a quality of service (QoS) parameter associated with a currently executed application, the QoS parameter being indicative of whether a handover from the cellular network to the WiFi network is permitted; and performing, by the station, a handover from the cellular network to the WiFi network when the performance data of the WiFi network satisfies a set of predetermined criteria for the network metrics and the QoS parameter indicates the handover is permitted.

The exemplary embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary embodiments are related to a device and method for a handover from a first wireless network type to a second wireless network type when a set of criteria has been satisfied to offload data. Specifically, the first wireless network type may be a cellular network while the second wireless network type may be a WiFi network or vice versa. When the second type of wireless network becomes available, the device and method may be configured to assess whether a handover should be performed based upon the criteria which may entail predetermined factors. The device, the wireless network types, the criteria, the predetermined factors, and a related method for data offloading will be explained in further detail below.

It should be noted that the description below relates to when a station is connected to a cellular network such that a wireless functionality may be performed such as a data transfer. The description below also relates to when the station is configured to perform a handover to a WiFi network (when available) such that the wireless functionality may be performed or continued. The cellular network may be, for example, a 3G network, a 4G network, a LTE network (depending on the naming institute), etc. The WiFi network may be, for example, a private network, a WiFi network, a HotSpot network, etc. The WiFi network may be based on, for example, IEEE 802.11a/b/g/n/ac technology, and/or any other appropriate IEEE 802.11 technology.

It should be also noted that the terms “joining,” “connecting,” and “associating” are used interchangeably in the description below. Specifically, these terms relate to when the station joins a wireless network. Those skilled in the art will understand that when the station joins a wireless network, an association process is performed in order for the station to connect to the wireless network. Those skilled in the art will also understand that any manner of association process may be used and the exemplary methods encompass any form of association or procedure in which the station is to connect to the wireless network.

When a user utilizes a station that is capable of connecting to various different types of wireless networks, the connection to the wireless network that provides an optimal experience should be made. For example, the station may connect to a cellular network. If a connection to a WiFi network that provides a more optimal experience is available, the station should connect to the WiFi network. The WiFi network may be configured to provide a faster rate at which data may be exchanged, a more reliable connection to the wireless network, etc. However, depending on a variety of factors that should be considered prior to this handover, the station must be configured to determine whether the WiFi network indeed provides this more optimal experience. For example, a disposition of the station may be such that there is a significant amount of interference that the cellular network remains to provide the more optimal experience despite the WiFi network ordinarily providing better connection parameters. Therefore, instead of a conventional automatic data offloading to the WiFi network from the cellular network, the station should remain on the cellular network such that the user is provided the most optimal experience given the current situation. In addition, during the course of being connected to the WiFi network, if conditions were to indicate that the cellular network provides a more optimal experience, the station should again determine whether a handover from the WiFi network to the cellular network should be performed. In this manner, a data offloading may be provided to the wireless network from which the station is handed over.

It should be noted that the WiFi network normally providing a more optimal experience is only exemplary. That is, the WiFi network does not always provide the best data exchange rate, connection reliability, etc. Those skilled in the art will understand that the cellular network may provide the better connection parameters. For example, a current situation may indicate that the cellular network is more optimal than the WiFi network. In another example, the cellular network may be enhanced such that a more optimal experience is provided normally over the WiFi network. Accordingly, the device and method may relate to determining whether the station is to perform a handover from a connection to a WiFi network to a connection to a cellular network. As will be described in further detail below, the device and method determine whether the station is to perform the handover from a first wireless network to a second wireless network so long as a more optimal experience is provided.

FIG. 1shows an exemplary station100for an optimized handover between a cellular network and a WiFi network. The station100may represent any electronic device that is configured to connect to a wireless network and provide association functionalities such as relating to a data exchange. For example, the station100may be a portable device such as a cellular phone, a smartphone, a tablet, a laptop, etc. In another example, the station100may be a stationary device such as a desktop terminal. The station100may include a processor105, a memory arrangement110, a transceiver115, an antenna120, and other components125. For example, the other components125may include a portable power supply (e.g., battery) if the station100is portable, a data acquisition device, ports to electrically connect the station100to other electronic devices, a display device, an input/output device, etc.

The processor105may be configured to execute a plurality of applications of the station100. For example, the applications may include a web browser when connected to a communication network via the transceiver115. In another example, the processor105may execute an offloading manager106which is an application that determines whether a handover is to be performed when a WiFi network is available. The memory110may be a hardware component configured to store data related to operations performed by the station100. Specifically, the memory110may store network parameter data (e.g., metrics) related to operations of a wireless network that is currently connected or subsequently to be connected. The memory110may also store hysteresis data related to a connection to a wireless network and previous connections that may further indicate whether the handover is to be performed.

The transceiver115may be a hardware component configured to transmit and/or receive data. The transceiver115may therefore enable communication with other electronic devices directly or indirectly through a network. Specifically, the transceiver115may be configured to transmit requests for network related data. The transceiver115may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies) that are related to a cellular network and a WiFi network via the antenna120. For example, the antenna120may enable the transceiver115to operate in a low-band frequency operating range between 800-900 MHz for the cellular network while enabling the transceiver115to operate in a high-band frequency operating range between 1800-2100 MHz for the WiFi network.

The offloading manager106executed by the processor105may be configured to receive various network metrics and network related data including hysteresis data that is used as a basis to determine whether an available WiFi network is to be used for a handover from a cellular network. The offloading manager106may include a predetermined set of criteria such that the network metrics/related data provides the determination of whether or not to perform the handover. As will be described in further detail below, the criteria may include availability of the WiFi network, determining if a connection may be made to the WiFi network, determining whether the WiFi network provides a more optimal experience, determining if the hysteresis data indicates the WiFi network provides a more optimal experience, and determining any related quality of service (QoS) parameters for the handover.

FIG. 2shows an exemplary system200for an optimized handover between a cellular network205and a WiFi network210. The system200relates to the cellular network205having an operating area in which the WiFi network210has an operating area disposed therein. As illustrated, the WiFi network210may be wholly disposed within the operating area of the cellular network205. Thus, when the station100is within the operating area of the WIFi network210, the station100may associate with the cellular network205or the WiFi network210. However, when outside the operating area of the WiFi network (such as the station150), the station150may only be able to associate with the cellular network205. That is, a WiFi network210is unavailable for connection. However, if the station150were to move into the operating area of the WiFi network210(when the station150is portable or physically moved), the station150may also be able to associate with the WiFi network210along with the cellular network205. The determination of whether to data offload to the WiFi network210relates to the station100which is disposed within the operating area of the WiFi network210and also within the operating area of the cellular network205. However, as will be described in further detail below, an initial criterion of the set of criteria is to determine whether a WiFi network connection is available.

It should be noted that the configuration of the system200is only exemplary, specifically regarding the cellular network205and the WiFi network210. In a first example, the cellular network205has an operating area that is relatively large while the WiFi network210has an operating area that is relatively small in comparison. However, a configuration may be possible in which the WiFi network210has a larger operating area. In a second example, the WiFi network210has an operating area that is wholly disposed within the operating area of the cellular network. However, the WiFi network210may have a portion of its operating area that overlaps with the operating area of the cellular network205. When the station100is disposed within this overlapping area, the determination of whether to data offload may be performed. In a third example, the shapes of the operating areas of the cellular network205and the WiFi network210may be any shape, contiguous, separated, etc. In a fourth example, the use of only one cellular network and one WiFi network210is for illustrative purposes only. The cellular network205may be a wide area network in which the operating area may cover a significantly large area. A further cellular network may have an overlapping portion with the cellular network205. There may also be at least one further WiFi network disposed within or having an overlapping portion with the cellular network205. The multiple WiFi networks may also overlap within the cellular network205.

The exemplary methods provide a manner of optimizing a handover from a first network connection to a second network connection such that a data offloading may be performed to provide an optimal experience for a user. The station100may be disposed in a location such that a connection to the cellular network205and the WiFi network210is possible. The station150may also be moved to a location such that the connection to the cellular network205and the WiFi network210is possible. When the cellular network205and the WiFi network210are both available for a connection by the station100, the offloading manager106may determine whether a handover is to be performed based upon a set of criteria such that a most optimal experience may be provided to the user of the station100. That is, the offloading manager106determines whether a handover is to even be performed or when the handover is to be performed from the cellular network205to the WiFi network210.

FIG. 3shows an exemplary method300for an optimized handover between a cellular network and a WiFi network. The method300illustrates a process in which the station100connects to a first network type such as the cellular network205and determines whether a handover is to be performed to a second network type such as the WiFi network210. Specifically, the offloading manager106receives a plurality of network related data and station related data to determine whether the handover should be performed such that an optimal experience may be provided to the user of the station100. Accordingly, even when a conventionally known WiFi network that normally provides a more optimal performance is available, the station100determines whether the handover is to occur since a given set of circumstances of a situation may indicate that the WiFi network provides a sub-optimal performance. For example, physical layer (PHY) metrics may indicate when a handover is to occur which indicate a current set of circumstances that the station100is experiencing. The method300will be described with regard to the station100ofFIG. 1and the system200ofFIG. 2.

The method300may assume that the station100is currently associated with the cellular network205. Depending upon a variety of factors such as service contract details, the station100may establish a connection to the cellular network205whenever the station100is within the operating area of the cellular network205. Therefore, it may also be assumed that the station100is within the operating area of the cellular network205for the method300. The station100may join the cellular network205using any known association process such as utilizing the identity of the station100that indicates credentials or other subscription type data that indicates a user of the station is a customer of the cellular network205.

In step305, the offloading manager106determines whether WiFi networks are available. The offloading manager106may include a set of instructions such that an initial step includes generating a probe request that is transmitted via the transceiver115using known frequencies or channels via the antenna120for WiFi networks (e.g., 1800-2100 MHz). Thus, as illustrated inFIG. 2, the station100is within the operating area of the WiFi network210. A network component such as a server for the WiFi network210may generated a probe response to the probe request that is received by the station100and the offloading manager106. Accordingly, the offloading manager106may determine that the WiFi network210is available for connection. However, for the station150in its current disposition within the system200, the offloading manager106will not receive the probe response as it is located outside the operating area of the WiFi network210.

It should be noted that the memory110may store network related data that indicates whether the station100is within an operating area of a known WiFi network. For example, the processor105may execute a location application that determines the location of the station100. When the station100has previously joined a WiFi network, the offloading manager106may utilize the location of the station100to determine whether a known WiFi network is associated therewith. Accordingly, the offloading manager106may specify the probe request within a known channel corresponding to the known WiFi network. The offloading manager106may still transmit a respective probe request at all channels for WiFi networks or with a wildcard service set identifier (SSID) on all known channels to detect any available WiFi networks.

In step310, a determination is made whether the WiFi network210is available. It should be noted that for illustrative purposes, only the WiFi network210is considered for the method300. However, as will be described in further detail below, the method300may consider all available WiFi networks that are determined in step305. If no WiFi network is determined to be available, the method300continues to step315. In step315, the offloading manager106determines that the connection to the cellular network205is to be maintained.

If step310determines that the WiFi network210is available, the method300continues to step320. In step320, the offloading manager106determines if a connection is possible. Whether the station100may join the WiFi network210includes a variety of different considerations. For example, despite receiving the probe response from the network component of the WiFi network210, the network component may further include a data packet that indicates that no further connections may be made to the WiFi network210due to volume. Accordingly, the offloading manager106may receive an indication that the connection is not possible to the WiFi network210. In another example, despite receiving the probe response, the station100may transmit a subsequent request as to whether a connection to the WiFi network210is possible. Due to various reasons that those skilled in the art will understand, the network component may not provide a response to this subsequent request (e.g., within a predetermined amount of time). The offloading manager106may retry the request (e.g., a predetermined number of times). If no response is received, the offloading manager106may determine that the connection to the WiFi network210is not possible.

It should be noted that the memory110may store further network related data that indicates whether the station100is capable of connecting to the WiFi network210. For example, if the WiFi network210is known (e.g., known SSID) and the memory110stores corresponding authentication data (e.g., a password), the station100may be allowed to join the WiFi network210. However, if the WiFi network210is unknown and no corresponding authentication data is stored or provided, the station100may be incapable of joining the WiFi network210. In another example, the station100may have hardware or software components that prevent the station100from joining the WiFi network210. If the station100includes hardware/software that is of a previous generation or is in a different configuration, the station100may be incapable of joining the WiFi network210using the protocols used therein. The network component of the WiFi network210may transmit a data packet to the station100that indicates the hardware/software requirements in order for the connection to be established.

In step325, a determination is made whether the station100is capable of establishing a connection to the WiFi network210. If the station100is incapable of connecting to the WiFi network210, the method300continues to step315where the offloading manager106determines that the connection to the cellular network205is to be maintained.

If step325determines that the station100is capable of joining the WiFi network210, the method300continues to step330. In step330, the offloading manager106determines a performance of the WiFi network210. Specifically, the offloading manager106determines whether the WiFi network210provides a more optimal experience for the user than the current connection to the cellular network205. As discussed above, the offloading manager106may utilize a set of criteria to determine whether the handover is to be performed such that the data offloading from the cellular network205to the WiFi network210is to occur.

In a first criterion for performance, the offloading manager106may consider physical layer metrics. That is, the offloading manager106considers the networking hardware transmission technologies of the WiFi network210based upon, for example, the seven layer Open Systems Interconnection (OSI) model of computer networking. Accordingly, the first criterion may relate to a signal level determination including a measurement of a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal received quotient (RSRQ), a signal to interference plus noise ratio (SINR), etc. These may be determined, for example, from the probe response received from the network component of the WiFi network210. They may also be determined utilizing further messages or probe requests.

In a second criterion for performance, the offloading manager106may consider media access control (MAC) metrics. That is, the offloading manager106considers the data communication protocol of the WiFi network210based upon, again for example, the seven layer OSI model of computer networking. Accordingly, the second criterion may relate to throughput including a channel quality indicator (CQI), a number of resource blocks allocated in a downlink (DL), a DL block error ratio (BLER) (estimated from a DL cyclic redundancy check CRC), an estimated measure of a scheduling rate, a measure of latency, a measure of jitter, etc. These may also be determined, for example, from the probe response received from the network component of the WiFi network210, further messages, further probe requests, etc.

In step335, a determination is made whether the WiFi network210is more optimal than the cellular network205based upon the performance criteria described above. For example, each part of the criteria may have an associated predetermined threshold value. If select ones of the criteria (e.g., RSSI, RSRP, RSRQ, etc.) are above the threshold value, the offloading manager106may determine that the WiFi network210is more optimal. If select ones of the criteria (e.g., latency, jitter, etc.) are below the respective threshold value, the offloading manager106may again determine that the WiFi network210is more optimal. In another example, the offloading manager106may determine corresponding measurements for the cellular network205. Those skilled in the art will understand that substantially similar manners may be used to determine the same measurements in the cellular network205. Thus, the offloading manager106may compare the corresponding values of the criteria to determine whether which wireless network provides the more optimal user experience (e.g., a majority of the criteria is better for one wireless network over the other). If the offloading manager106determines that the cellular network is more optimal, the method300continues to step315where the offloading manager106determines that the connection to the cellular network205is to be maintained.

If step335determines that the WiFi network210is more optimal than the cellular network, the method300continues to step340. In step340, the offloading manager106determines hysteresis data for the station100. Specifically, the offloading manager106references handover data stored in the memory110regarding parameters related to prior handovers. Accordingly, the offloading manager106is able to utilize network data as well as station data in determining whether the handover is to be performed.

The hysteresis data may be a moving window average that is a measure for determining a relative timing of how the device is to perform the handover to the WiFi network210. The average may be based upon a past history of a manner in which transfers or handovers to the WiFi network210happened in terms of a user profile such as how long the user stays in a particular radio access technology (RAT) (e.g., cellular, WiFi, etc.) and applications being executed by the processor105using the respective RAT. The average may also be used as a performance metric to determine whether the device is in a transitioning state in the WiFi network210. Accordingly, the hysteresis data may indicate whether the handover is to be performed in view of the past history of the user of the station100. Again, the hysteresis data may be stored in the memory110in which the relevant data regarding the above identified aspects are generated at the time (or at a later time) it occurred.

In step345, a determination is made whether the offloading manager106is to perform the handover based upon the hysteresis data. If the determination indicates from the hysteresis data that the handover to the WiFi network210is not to be performed, the method300continues to step315where the offloading manager106determines that the connection to the cellular network205is to be maintained. However, if a determination is made that the handover to the WiFi network210is to be performed, the method300continues to step350.

In step350, the offloading manager106determines whether any QoS considerations exist. Specifically, the QoS considerations may relate to applications that are being executed by the processor105at the time the handover is to occur. Those skilled in the art will understand that select applications have a related QoS to ensure that the performance of the application is not affected from performing the handover. For example, a voice application (e.g., VoIP, VoLTE, etc.) requires no breaks in the connection to the other electronic device. Accordingly, the offloading manager106determines the applications that are being executed such that any corresponding QoS consideration is to be included in the determination of whether the handover is to be performed.

In step355, a determination is made whether any QoS consideration exists for the handover to be performed. Thus, for example, if the processor105is currently executing a voice application, the offloading manager106determines that a QoS consideration exists such that the offloading manager106further determines that there should be no break in the service (i.e., no handover should be performed). Accordingly, the method300continues to step315where the offloading manager106determines that the connection to the cellular network205is to be maintained. However, the offloading manager106may determine that there is no QoS consideration. For example, the processor105may be in an idle state with regard to other applications such that no further applications are currently being executed. Thus, the method300continues to step360. In step360, as all criteria have been satisfied for the handover to be performed, the station100disconnects from the cellular network205such that a connection to the WiFi network210is established. As discussed above, the station100may associate with the WiFi network210using any known manner of association. For example, a password may be forwarded to the network component of the WiFi network210indicating authentication for the association.

After step360, the method300returns to step330in which the performance of the WiFi network210is again determined. In this manner, the method300allows for a dynamic process in which the station100may join the most optimal wireless network given a set of conditions that the station100and the wireless networks are experiencing. For example, during the course of the connection with the WiFi network210, further stations may join the WiFi network210and utilize a majority portion of the available bandwidth such that the performance of the WiFi network210relative to the station100becomes sub-optimal. The offloading manager106may perform steps330-335to determine whether the WiFi network210is still optimal to the cellular network205. It should be noted that the offloading manager106may determine the performance metrics for the cellular network205as well to serve as a basis for the determination. If the offloading manager106concludes that the cellular network205has become more optimal to the WiFi network210that the station100is currently connected, the method300allows for the offloading manager106to handover the connection from the WiFi network210to the cellular network205to provide the most optimal experience to the user. Accordingly, as the station100is handed over, several effects take place such as data being offloaded from the WiFi network210and the station100being provided a more optimal connection for data exchange.

It should be noted that the exemplary method300described above may include further steps. In a first example, as described above, there may be multiple WiFi networks that the station100may join. When multiple WiFi networks exist having overlapping operating areas in which the station100is located, the station100may select the most optimal WiFi network to perform the handover from the cellular network205. Accordingly, step305of the method300may include a further step of generating a list of the available WiFi networks beyond the WiFi network210. The subsequent steps may then be performed for each of the WiFi networks that are determined to be available. The offloading manager106may then determine the most optimal WiFi network among the available ones for the handover to be performed.

In a second example, the offloading manager106may provide a prompt for various reasons. The offloading manager106may enable an automatic process for the method300such that the user is not required to provide any input as to whether the handover is to occur. However, the offloading manager106may also be configured to allow the user to provide manual inputs during the performance of a handover. For example, after step355, the offloading manager106may indicate that the connection to the WiFi network210is more optimal than the current connection to the cellular network205. The offloading manager106may provide a prompt whether the user wishes to perform the handover. In another example, the offloading manager106may provide a prompt for authentication data such as a password when a connection to the WiFi network210is established. In yet another example, the offloading manager106may have access to a subscription policy for the user of the station100such as credentials or other subscription type data. The offloading manager106may then determine whether the handover should be performed based upon this further criterion. If the subscription policy includes a data usage limit and the user has already exhausted or nearly exhausted this allotment, the offloading manager106may prompt the user indicating this aspect. The user may then manually indicate whether a connection to the cellular network205should still be used in view of this condition. In a specific example, if the station100is currently streaming a large data file (e.g., a movie), the offloading manager106may prompt the user that a handover should be performed to the WiFi network210as it may be more ideal, the data usage indicated by the subscription policy is exhausted, etc. Even if the WiFi network210has been determined to provide a sub-optimal experience, the offloading manager106may still prompt the user for a handover to the WiFi network210such that the user does not exceed the data usage limit.

In a third example, the method300may include generating a timer, particularly after determining the applications being executed. For example, the processor105may be executing a data transfer application. During the data transfer application, a time sensitive application such as a voice application may be executed. The data transfer application may be suspended for the length of the timer. Once the timer has lapsed, the offloading manager106may determine whether the time sensitive application has concluded. If still ongoing, the time sensitive application may be continued for another length of the timer when a subsequent check is performed. Once the check is performed and the time sensitive application has concluded, the offloading manager106may determine the available WiFi networks prior to continuing the data transfer application. Accordingly, the offloading manager106may suspend the data transfer application until the determination of whether a handover is to be performed is made. If the handover from the cellular network to the WiFi network is performed, the data transfer application may continue. If a connection to the cellular network is maintained, the data transfer application may still continue.

The exemplary embodiments provide a device and method for an optimized handover to a wireless network that provides a most optimal experience for a user of a station given a current set of conditions. The station may include a processor executing an offloading manager that determines the most optimal wireless network. Specifically, when connected to a cellular network, the offloading manager may determine whether a connection to a WiFi network is more optimal. When connected to a WiFi network, the offloading manager may determine whether a connection to the cellular network is more optimal. The offloading manager may utilize a variety of factors to determine whether the handover is to be performed. The factors may include the availability of the other network, the possibility of a connection to the other network, a performance comparison between the currently connected network and the other network, a hysteresis determination for the station, and QoS considerations, particularly for applications being executed by the processor at the time of the handover. The handover to the other network allows for the station to have the most optimal connection under the set of conditions as well as offload data of the network that the station was previously connected prior to the handover. It should be noted that the handover process does not require to be seamless. For example, there may be no requirement for an Internet Protocol (IP) to be retained.

It will be apparent to those skilled in the art that various modifications may be made in the present invention, without departing from the spirit or the scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalent.