Control of antenna use by a wireless communication device

Abstract

A wireless communication device (WCD) has multiple antennas including a first antenna and a second antenna and that is configured to use just one of the antennas at a time to wirelessly communicate using a particular radio access technology. The WCD uses the first antenna to receive active baseline wireless communication from another device and measures wireless performance of the baseline wireless communication received via the first antenna. The WCD further switches to use the second antenna to receive from the other device an extraneous wireless communication and measures wireless performance of the extraneous wireless communication received via the second antenna. The WCD then compares the measured wireless performance of the active baseline wireless communication received via the first antenna with the measured wireless performance of the extraneous wireless communication received via the second antenna and, based on the comparison, controls which antenna to use moving forward.

Description

Control of Antenna Use by a Wireless Communication DeviceREFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 574,635, filed April 4, 2024, the entirety of which is hereby incorporated by reference.BACKGROUND

[0002] A typical wireless communication device may include an antenna structure and associated circuitry to facilitate engaging in wireless (e.g., radio frequency (RF)) communications, such as Bluetooth, Wi-Fi, Zigbee, ultra-wideband, microwave, or cellular communications, among other possibilities.SUMMARY

[0003] This present disclosure relates to wireless communications, where a representative device is equipped with multiple antennas to facilitate wireless communication with another wireless endpoint but is configured to use just one of the antennas at a time for wireless communication according to a particular radio access technology (RAT) . By way of example, the device may include wireless communication circuitry defining an RF chain that facilitates communication through each antenna, and the device may include a processor- controlled switch for selectively connecting that RF chain with one of the multiple antennas at a time.

[0004] A representative RF chain may include transmit (Tx) and receive (Rx) subchains, for instance, with the Tx sub-chain including a modulator for modulating outbound signals onto an RF carrier and a power amplifier for amplifying the outbound signals for wireless transmission, and with the Rx sub-chain including a low noise amplifier for amplifying wirelessly received inbound signals for processing and a demodulator for demodulating those inbound signals. In accordance with a particular RAT (e.g., a particular short-range-wireless RAT) This or another such RF chain may support communication through just a single antenna at a time.

[0005] For various reasons, the quality of wireless communications between the device and the other wireless endpoint may differ from time to time depending on which antenna the device uses for the communications in accordance with the particular RAT. For instance, at times, the air-interface communication path between one of the antennas and theother wireless endpoint may be stronger, have less interference, or otherwise be higher quality than the air-interface communication path between another one of the antennas and the other wireless endpoint. When the communication path between the device and the other wireless endpoint is higher quality, the device and the other wireless endpoint may each have higher receive-signal strength (e.g. signal -to-noise ratio), which may in turn allow use of lower transmission power and increase the likelihood of successful communication.

[0006] To help ensure that the device uses the antenna that would provide the best wireless performance (e.g., wireless communication quality), a processor of the device may monitor wireless performance respectively using each antenna and may configure the device accordingly. For instance, the processor may switch the device’s RF chain between the antennas and, while the RF chain is connected respectively with each antenna, may determine wireless performance as a measure of receive-signal strength (e.g., receive signal strength indicator (RSSI)) and / or rate of retransmissions that the device requests or retransmission requests that the device receives, among other possibilities. By comparing the wireless performance respectively per antenna, the processor may then select the antenna that would seem to provide the best wireless performance and may set the RF chain to be connected with the selected antenna.

[0007] As a specific example of this, for communication in accordance with the particular RAT, the processor may configure the device to operate with a first one of the antennas, and while the device is so configured, the processor may monitor wireless performance using that first antenna. If and when the processor thereby determines that the wireless performance using the first antenna drops below a threshold, the processor may then switch the device to operate with a second one of the antennas and may measure wireless performance using the second antenna. Based on a comparison of the determined wireless performance using the first antenna and the determined wireless performance using the second antenna, the processor may then control whether to have the device continue operating with the second antenna or rather to have the device revert to operate with the first antenna.

[0008] Unfortunately, however, this process can pose technical problems, because the processor would not know the wireless performance using the second antenna until the processor actually switches the device to use that second antenna.

[0009] In some cases, the wireless performance using the second antenna may be worse than the wireless performance using the first antenna. Therefore, having the device operate using the second antenna for even just a short period of time to allow the processor tomeasure the wireless communication quality using the second antenna may degrade communications between the device and the other wireless endpoint or may cause other issues. Further, in some cases, before the wireless performance using the first antenna drops to a low enough level to trigger the processor measuring wireless performance using the second antenna, the wireless performance using the second antenna may actually be better than the wireless performance using the first antenna. Yet the processor would not yet know this, and so the device would not yet benefit from the improved wireless performance (e.g., with associated reduced power consumption) using the second antenna.

[0010] The present disclosure provides improvements that may help address these problems.

[0011] In one respect, the disclosure provides for introducing an extraneous communication between the device and the other wireless endpoint, and having the device measure wireless performance as to that extraneous communication using the second antenna. In particular, this process could involve causing the other wireless endpoint to transmit to the device an extraneous communication, and having the device switch to use the second antenna for receiving the extraneous communication and measure wireless performance, such as receive-signal strength, of extraneous communication.

[0012] The extraneous communication in this process could be a communication that is not part of, or otherwise needed for, the normal flow of communication between the device and the other wireless endpoint. For instance, the normal flow of communication between the device and the other wireless endpoint may define “active baseline wireless communication” including possibly data-link communication with associated acknowledgement signaling and control-link signaling that may control or coordinate the data- link communication. The extraneous communication may then define an “extraneous wireless communication” that is not part of that active baseline wireless communication and may be of no particular use in that active baseline wireless communication but that may facilitate the present wireless-performance monitoring.

[0013] The device can thus safely switch to its second antenna to measure wireless performance as to the extraneous communication, with little or no risk of degrading the normal flow of communication if it turns out that the measured wireless performance using the second antenna is poor. Further, the device can carry out this process essentially as a background process as often as practical, to help ensure that the device regularly uses the antenna that would provide the best wireless performance from time to time as conditions change.

[0014] In another respect, the disclosure provides for using a wireless control link as a basis to monitor wireless performance per antenna without switching data link communication from one antenna to another. This implementation may be particularly useful, for instance, in a scenario where data being communicated between the device and the other wireless endpoint is especially sensitive to issues that may result from antenna switching. Examples of such a scenario include Bluetooth communication of voice using the standard Hands Free Profile (HFP) and Bluetooth Low Energy (LE) communication of audio using the latest LE audio standards.

[0015] In an example implementation, the device and other wireless endpoint may have co-existing, established wireless links separately for control and data communication, namely, a wireless control link and a wireless data link. The control link may carry controlplane communications, such as null packets to maintain synchronization, a channel map to facilitate adaptive frequency hopping (AFH), and power-control signaling to control transmission power based on receive signal strength, among other possibilities. The data link, on the other hand, may carry user-plane communications, such as digitized voice or other media, among other possibilities.

[0016] As the device uses just a single antenna at a time for communication in accordance with the particular RAT, the device’s communication may be time-division multiplexed between the control link and the data link, with an agreed frame structure that defines time segments when the data link would exist and time segments when the control link would exist. Thus, over time, there may be separately defined control-link intervals and data- link intervals.

[0017] With this arrangement, the device could thus safely switch from antenna to antenna to measure wireless performance as to communication in one or more control-link intervals, also with little or no risk of degrading the normal flow of communication. And the device could carry out this process also as a background process as often as practical, to help ensure that the device regularly uses the antenna that would provide the best wireless performance from time to time as conditions change.

[0018] Note that having a device evaluate wireless performance per antenna using an extraneous communication and / or using a control link as described herein may be especially useful in a scenario where there is no broadcast reference signal or the like that the device might otherwise be able to measure in order to determine wireless performance. However, the principles described herein are not limited to that scenario.

[0019] These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that the descriptions provided in this summary and below are intended to illustrate the invention by way of example only and not by way of limitation.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a simplified illustration of an arrangement in which various features could be implemented.

[0021] Figure 2 is a simplified block diagram illustrating components of a device including multiple antennas and an RF chain that can be selectively switched between the antennas.

[0022] Figure 3 is a message flow diagram illustrating example operations.

[0023] Figure 4 is another message flow diagram illustrating example operations.

[0024] Figure 5 is a flow chart illustrating an example method.

[0025] Figure 6 is a simplified block diagram of an example wireless communication device.DETAILED DESCRIPTION

[0026] Referring to the drawings, as noted above, Figure 1 is a simplified block diagram of an arrangement in which various disclosed features could be implemented. In particular, the figure illustrates a first example wireless communication device 100, a second example wireless communication device 102, and example wireless communication 104 between the devices.

[0027] Devices 100, 102 may each take various forms, examples of which may include without limitation, a smartphone, a laptop, a tablet, a smartwatch, a fitness tracker, earbuds or headphones, a sound speaker, a gaming device, a smart-home device, an Internet of Things (loT) device, a tracking device, and / or an access point or base station. Further, the wireless communication 104 between these devices may also take various forms and may be compliant with an agreed wireless communication protocol, i.e., RAT, examples of which may include, without limitation, personal area network (WPAN) protocols such as Bluetooth, ultra- wideband, or Zigbee, wireless local area network (WLAN) protocols such as Wi-Fi ormicrowave, and terrestrial or non-terrestrial wireless wide area network (WWAN) protocols such as 4G Long Term Evolution (4G LTE) or 5G New Radio (5G NR).

[0028] The present description will discuss example implementations in the context of short-range wireless communications, such as but not limited to Bluetooth (e.g., Bluetooth Low Energy (BLE)) communications, as defined by the Bluetooth Special Interest Group (Bluetooth SIG). However, it will be appreciated that the disclosed principles could apply as well with respect to other wireless communication protocols, including but not limited to those noted above.

[0029] More generally, it will be understood that the disclosed arrangements and processes are set forth for purposes of example only and may take various other forms. For instance, elements and operations can be re-ordered, distributed, replicated, combined, omitted, added, or otherwise modified. In addition, it will be understood that functions described herein as being carried out by one or more components could be implemented by and / or on behalf of those components, through hardware, firmware, and / or software, such as by one or more processing units executing program instructions or the like.

[0030] In the arrangement of Figure 1, device 100 could be the representative device discussed above, and device 102 could be the other wireless endpoint discussed above. Thus, as shown in Figure 1, at least device 100 could be equipped with multiple antennas 106 to facilitate its wireless communication with device 102.

[0031] Each antenna 106 of device 100 could take any of a variety of forms, possibly depending on the device type. Without limitation, example types of antennas may include a planar monopole antenna, an inverted-F antenna, a patch antenna, a helical antenna, a slot antenna, and a dipole antenna, and combinations of these and / or others. Further, each antenna may be a single antenna or may be a combination of antennas or antenna elements, such as an antenna array, among other possibilities. Although the figure shows antennas 106 as extending outside of device 100, the antennas 106 may be included wholly or partly within the device, also depending on device type. Further, the device 100 may include one or more other antennas aside from those at issue here.

[0032] Having multiple antennas in device 100 may facilitate antenna diversity, enabling the device 100 to communicate over a physically separate RF communication paths with the other device 102, which may help to mitigate user experience issues or other issuesrelated to degraded communication quality when one of the antennas is shadowed, e.g., where an RF obstruction or other problem causes path loss in the antenna’s RF communication path.

[0033] As noted above, however, the example device 100 is configured to use just one of these antennas 106 at a time for its wireless communication according to the example RAT. For instance, as noted, the device 100 may include wireless communication circuitry defining an RF chain that facilitates communication through each antenna, and the device may include a processor-controlled switch that selectively connects that RF chain with just one of the antennas at a time. This arrangement would thus provide single-chain diversity.

[0034] Figure 2 illustrates an example of this arrangement, where the device 100 includes two example antennas 200, 202 and has an RF chain 204 that can be selectively connected with one of those antennas at a time for Bluetooth communication.

[0035] In particular, Figure 2 shows the RF chain 204 including a Bluetooth chipset 206 and an RF front end (RFFE) 208, with a processor-controlled switch 210 providing selective connectivity with the antennas 200, 202. With this example arrangement, the Bluetooth chipset 204 includes a processor 212 (e.g., a digital signal processor (DSP)) that may be programmed to function as a Bluetooth radio 214 (e.g., to modulate and demodulate Bluetooth signals) and a Bluetooth link controller 216 (e.g., to manage device discovery, connection establishment, data packetization, error correction, and flow control), and that may further be programmed to control RF switch 210. The RFFE 208 then includes a power amplifier (PA) 218 for amplifying outbound signals for wireless transmission and a low noise amplifier (LNA) 220 for amplifying wirelessly received inbound signals for processing.

[0036] Various other device configurations may be possible as well. For instance, the RFFE 208 may include additional components, such as one or more RF filters and mixers, among other possibilities. Further, one or more components of the RFFE 208 may be provided as components of the Bluetooth chipset instead 204, possibly as a unified RF integrated circuit (RFIC) including both the Bluetooth processor 212 and the RFFE components, among other possibilities. Other examples are possible as well.

[0037] With the example arrangement of Figure 2, the processor 212 of the Bluetooth chipset 204 may dynamically control the position or state of the switch 210, to selectively connect the Bluetooth chipset 204 (e.g., the Bluetooth radio 214) through the RFFE 208 with one of the two antennas 200, 202 at a time. When the switch 210 provides connectivity with antenna 200, any outbound Bluetooth communications may flow through the RFFE 208 from the Bluetooth chipset 204 to antenna 200 and may be transmitted wirelessly from antenna200, and any inbound Bluetooth communications wirelessly received by antenna 200 may flow through the RFFE 208 from antenna 200 to the Bluetooth chipset 204. Whereas, when the switch 210 provides connectivity with antenna 202, any outbound Bluetooth communications may flow through the RFFE 208 from the Bluetooth chipset 204 to antenna 202 instead and may be transmitted wirelessly from antenna 202, and any inbound Bluetooth communications wirelessly received by antenna 202 may flow through the RFFE 208 from antenna 202 to the Bluetooth chipset 204.

[0038] Bluetooth communications between device 100 and 102 may take any of various forms. The communications may be bidirectional or unidirectional, with device 100 both transmitting to and receiving from device 102, or with device 100 just transmitting to or receiving from device 102 (the latter possibly for broadcast communications, among other possibilities). Further, the communications may use various Bluetooth protocol versions, such as Bluetooth Classic or Bluetooth Low Energy (BLE), and may be for various types of services, using any of various Bluetooth service profiles for instance, examples of which may include audio streaming (e.g., Advanced Audio Distribution Profile (A2DP)), voice call communication (e.g., HFP), and device control communication (e.g., Human Interface Device (HID) profile).

[0039] By way of example, Bluetooth communication between the devices may be BLE audio communication using the Basic Audio Profile (BAP) defined by Bluetooth SIG, which may facilitate A2DP or HFP audio communication, among other possibilities.

[0040] Under the BLE audio protocol, when a transmitting device or “initiator” has an audio stream to transmit to a receiving device or “acceptor” for real-time playout, the initiator could encode the audio using an audio codec (e.g., an LC3 codec), divide the encoded audio into a sequence of service data units (SDUs), translate the SDUs into protocol data units (PDUs), and wirelessly transmit the sequence of PDUs to the acceptor for receipt, decoding, and playout. Further, the BLE audio protocol specifies that the transport of this PDU sequence would occur on an “isochronous stream” that is divided over time into defined intervals and sub-intervals for carrying audio packets and associated information. In particular, for unicast audio transmission, the BLE audio protocol provides for transmitting the PDUs from the initiator to the acceptor on one or more connected isochronous streams (CISs) encompassed by a connected isochronous group (CIG) that defines recurring isochronous time intervals each for carrying a respective PDU in an audio packet from the initiator to the acceptor.

[0041] Like many other wireless communication protocols that could be subject to the principles disclosed herein, this BLE unicast audio arrangement supports an acknowledgement and retransmission scheme to help ensure successful receipt of transmitted data.

[0042] With BLE audio, each isochronous interval would carry transmission of a given audio packet and would be divided into sub-intervals for carrying transmission and possible retransmission of that audio packet from the initiator to the acceptor, and for carrying acknowledgement signaling from the acceptor to the initiator.

[0043] In each isochronous interval, the initiator would transmit an audio packet, and the acceptor would attempt to receive that packet and would run a cyclic-redundancy-check or other analysis to determine if it successfully received the packet. If the acceptor determines that it successfully received the packet, then the acceptor would responsively send to the initiator in the same isochronous interval a positive acknowledgement (ACK), which would complete the transmission of that packet. Whereas, if the acceptor determines that it did not successfully receive the packet, then then acceptor may instead send to the initiator in the same isochronous interval a negative acknowledgement (NACK), and if the initiator receives from the acceptor a NACK or at least does not receive an ACK for the packet transmission, the initiator may then responsively retransmit the packet in the same isochronous interval to the acceptor.

[0044] In some cases, each retransmission of a packet may be a partial retransmission and may carry some forward-error-correction bits to help facilitate successful receipt. Further, depending on the CIG configuration, each isochronous interval may support up to a predefined maximum number of such retransmissions, before the devices then proceed to the next isochronous interval for communication of a next packet.

[0045] In an example implementation, communication of audio and / or other userplane data between device 100 and device 102 may be unidirectional or bidirectional. For instance, with BLE audio, just one of the devices may send audio data on one or more CISs to the other device, or each device may send audio data on one or more CISs to the other device. In either case, the devices may optionally implement an acknowledgement and retransmission scheme like that described above to help ensure successful receipt of audio packets.

[0046] To facilitate BLE or other forms of Bluetooth data communication between devices 100, 102, the devices may have a separate established control communication session with each other, which they may use as a basis to set up and control their data communication.This control communication session may be an asynchronous connection-oriented logical transport (ACL) link for example. To set up an ACL link, one of the devices may first broadcast an advertisement packet, the other device may discover the advertisement packet and send a connection request to the first device, and the devices may then engage in further signaling with each other to set up the link.

[0047] Through an ACL link or other established communication session between the devices, the devices may then agree on terms of their data communication. For instance, the devices may agree on a channel map that defines a set of Bluetooth frequency channels to be used for adaptive frequency hopping of their data communication. Further, for BLE audio, the devices may agree on a CIG configuration, such as the isochronous interval and sub-interval timing, the maximum number of allowed retransmissions per isochronous interval, and so forth. The devices may then proceed to engage in their data communication.

[0048] Further, the devices may maintain their control link during their data communication, for their use to control aspects of their ongoing data communication. Through an established ACL link, for instance, the devices may change their channel map and / or other operational parameters of their communication. (In practice, if the devices use common resources for their data-link communication and their control-link communication, the devices may time division multiplex the data link with the control link. For instance, with BLE audio, the devices may engage in ACL communication during an isochronous interval after the devices engage in successful audio-packet communication. Other arrangements are possible as well.) The devices may then continue accordingly with their communication.

[0049] In practice, the quality of wireless communication between device 100 and device 102 may vary from time to time as noted above, depending on which of the antennas 200, 202 device 100 is set to use. For instance, if each antenna has a separate respective RF communication path, wireless communication between the devices using one of the antennas may be stronger and / or have less interference and / or noise than wireless communication between the devices using the other antenna. Consequently, when device 100 uses a given one of its antennas for communication with device 102, the wireless performance of those communications may be better than when device 100 uses the other of its antennas for communication with device 102.

[0050] The wireless performance as to communications between device 100 and device 102 may relate to wireless communication from device 100 to device 102 and / or wireless communication from device 102 to device 100. Further, the wireless performancecould be measured in various ways, such as based on receive-signal strength, signal-to-noise ratio (SNR), or signal-to-interference-plus-noise ratio (SINR), and / or based on retransmission rate.

[0051] Device 100 may monitor this wireless performance separately and respectively for each of its antennas, to keep track of the wireless performance per antenna. For instance, as device 100 uses a given one of antennas 200, 202 to engage in wireless communication with device 102, the processor 212 of device 100 could keep a measure (e.g., a running average over time) of receive-signal strength, SNR, and / or SINR of communications that it receives from device 102, and / or the processor could keep a measure (e.g., a running average overtime) of the retransmission rate. As to retransmission rate, if device 100 transmits data to device 102 and receives acknowledgement messaging from device 102, the retransmission rate could be a measure of what portion of transmitted packets device 100 needed to retransmit, possibly weighted further based on how many per-packet retransmissions were required. Alternatively or additionally, if device 100 receives data from device 102, the retransmission rate could be a measure of what portion of transmissions from device 102 device 100 did not successfully receive and as to which device 100 therefore requested retransmission. Other wireless performance metrics could be possible as well.

[0052] Based on a comparison of its monitored wireless performance using antenna 200 with its monitored wireless performance using antenna 202, the processor 212 of device 100 could usefully control which of the antennas to configure device 100 to use. For instance, if the processor 212 determines that the wireless performance using antenna 200 is better than the wireless performance using antenna 202, then, based at least on that determination, the processor 212 may cause the device 100 to use antenna 200. Whereas, if the processor 212 determines that the wireless performance using antenna 202 is better than the wireless performance using antenna 200, then, based at least on that determination, the processor 212 may cause the device 100 to use antenna 202.

[0053] As noted above, the present disclosure provides technical mechanisms to facilitate this control process in a manner that may help avoid interrupting the data communication between device 100 and device 102. In particular, at issue could be a scenario where device 100 is currently set to use antenna 200 for its communication with device 102,and where device 100 would need to switch to use antenna 202 in order to determine wireless performance using antenna 202.

[0054] The following subsections will discuss example mechanisms, which could also be combined together if desired.Use of Extraneous Wireless Communication as a Basis to Measure Wireless Performance Using Another Antenna

[0055] One implementation as noted above involves introducing an extraneous communication between the devices and measuring wireless performance as to that extraneous communication using the second antenna. In particular, this process could involve device 100 causing device 102 to transmit to device 100 an extraneous communication, and device 100 switching to use antenna 202 antenna for receiving the extraneous communication and measuring wireless performance, such as receive-signal strength, SNR, or SINR, of the extraneous communication.

[0056] The extraneous communication in this process could be a communication that is not part of, or otherwise needed for, the normal flow of communication between the device 100 and device 102. For instance, the normal flow of communication between devices 100, 102 may define what might be characterized as “active baseline wireless communication,” including possibly data-link communication with associated acknowledgement signaling and possibly other control-link signaling that may control or coordinate the data-link communication. The extraneous communication may then define an extraneous wireless communication that is not part of that active baseline wireless communication and may be of no particular use in that active baseline wireless communication but that may facilitate the present wireless-performance monitoring.

[0057] Device 100 can thus safely switch from antenna 200 to antenna 202 to measure wireless performance of the extraneous communication with little or no risk of degrading the normal flow of communication if it turns out that the measured wireless performance using antenna 202 is poor. Further, device 100 can carry out this process essentially as a background process as often as practical, to help ensure that device 100regularly uses the antenna that would provide the best wireless performance from time to time as conditions change.

[0058] The following two subsections discuss two example implementations of using extraneous communication as a basis to measure wireless performance using the second antenna 202. Other examples may be possible as well.Use Extraneous Retransmission of a Successfully Received Packet as a Basis to Measure Wireless Performance Using Other Antenna

[0059] One example of the extraneous communication is retransmission of a packet from device 102 to device 100 after device 100 has already successfully received the packet.

[0060] This example could apply in a scenario where device 102 wirelessly transmits to device 100 a sequence of packets and where device 100 and device 102 use an acknowledgement and retransmission scheme to help ensure successful receipt of each packet.

[0061] For instance, this could apply with the BLE audio transmission process discussed above as to audio transmitted from device 102 to device 100, where, for each audio packet transmitted from device 102 to device 100, device 100 would either (i) determine, through a CRC analysis for instance, that it successfully received the packet and therefore send to device 102 an ACK, effectively indicating completion of that audio-packet transmission or (ii) determine, through a CRC analysis for instance, that it did not successfully receive the packet and therefore send to device 102 a NACK or no acknowledgement, thereby causing device 102 to retransmit the packet from device 102 to device 100.

[0062] This acknowledgement and retransmission scheme is based on the understanding that, once device 100 successfully receives a packet transmitted by device 102, the act of transmitting that packet from device 102 to device 100 is complete, so device 100 should then send an ACK to device 102 to cause device 102 to proceed to transmission of a next packet in the sequence.

[0063] In accordance with the present disclosure, however, when device 100 successfully receives through antenna 200 a packet wirelessly transmitted from the device 102, device 100 could unconventionally trigger an extraneous retransmission of that packet from device 102, and device 100 could use that extraneous retransmission as a basis to measure wireless performance using antenna 202. In particular, processor 212 of device 100 couldunconventionally trigger this extraneous retransmission, switch device 100 to antenna 202, and measure wireless performance using antenna 202 to receive the extraneous retransmission.

[0064] Accordingly, when device 100 is currently configured to use antenna 200, device 100 could successfully receive a packet transmitted from device 102, and, in response to that successful receipt, device 100 could then (i) negatively acknowledge the successfully- received packet, such as by sending to device 102 a NACK or no acknowledgement, as a request for retransmission of that successfully-received packet and (ii) switch to use antenna 202 to receive that retransmission. (In an implementation where device 100 will thus send a NACK as a request for retransmission of the successfully-received packet, device 100 may optionally switch from antenna 200 to antenna 202 before sending the NACK and may then send the NACK using antenna 202 as well.)

[0065] As device 100 uses antenna 202 to receive this retransmission from device 102 of the packet that device 100 already successfully received from device 102, device 100 could then measure wireless performance of that retransmission, such as receive-signal strength, SNR, or SINR for instance. And device 100 could compare this measured wireless performance using the antenna 200 with its measured wireless performance using the antenna 200, as a basis to control whether to use the second antenna rather than the first antenna moving forward.

[0066] In this process, if device 100 had recently (e.g., within a predefined threshold short time window) determined wireless performance using antenna 200 before device 100 switched to use antenna 202 for receiving and measuring wireless performance of the retransmission, then device 100 could use the wireless-performance comparison as a basis to control whether to continue with use of antenna 202 or rather to switch back to use antenna 200. For instance, if device 100 thereby determines that the wireless performance using antenna 202 is better than the wireless performance using antenna 200, then, based on that determination, device 100 may continue to use antenna 202 rather than reverting to use antenna 200. Whereas, if device 100 thereby determines that the wireless performance using antenna 200 is better than the wireless performance using antenna 202, then, based on that determination, device 100 may revert to use antenna 200 rather than continuing to use antenna 202.

[0067] Alternatively, if device 100 had not recently determined wireless performance using antenna 200 before the device switched to use antenna 202 for receiving and measuring wireless performance of the retransmission, then, upon switching back to useantenna 200 after measuring wireless performance of the retransmission using antenna 202, the device could measure wireless performance using antenna 200 and could then perform the wireless-performance comparison as a basis to control which of antennas 200, 202 the device 100 should use moving forward. If device 100 thereby determines that the wireless performance using antenna 202 is better than the wireless performance using antenna 200, then, based on that determination, device 100 may switch to use antenna 202 moving forward, rather than continuing to use antenna 200. Whereas, if device 100 thereby determines that the wireless performance using antenna 200 is better than the wireless performance using antenna 202, then, based on that determination, the device may continue to use antenna 200 rather than switching to use antenna 202.

[0068] Potential downsides to causing retransmission of a successfully received packet are that the act of retransmission may burden processing resources at both ends and may also increase air-interface congestion. Given these concerns, in an example implementation, device 100 could be configured to carry out this process in just certain scenarios. For instance, device 100 could be configured to carry out the process in response to a time trigger, such as periodically with a period on the order of tens of packets or hundreds of packets, among other possibilities. Further, device 100 could be configured to carry out the process in response to an evaluation of operational state, such as (i) in response to determining that wireless performance using antenna 200 is at least as poor as a predefined low-quality threshold (notwithstanding the issue with this as noted above), and / or (ii) in response to determining that the battery energy of device 100 (if applicable) is at least as low as a predefined threshold level, among other possibilities. Still further, if device 100 is set to periodically carry out the process, device 100 might also forgo carrying out the process in response to determining that wireless performance using antenna 200 is at least as good as a predefined high-quality threshold.

[0069] Note also that device 100 could carry out this analysis based on a running average over a recent sliding window of measurements. For instance, device 100 could use this process as a basis to take multiple measurements over time of wireless performance using antenna 200 and multiple measurements over time of wireless performance using antenna 202, and device 100 could compare a running average of wireless performance using antenna 200 with a running average of wireless performance using antenna 202, as a basis to control which of the antennas to have device 100 use moving forward.

[0070] This process could also be carried out analogously with more than two antennas. For instance, if device 100 has three or more antennas, device 100 could measurewireless performance respectively using each of those antennas, by successively requesting retransmission of a successfully received packet (up to an allowed number of retransmissions) and using a different antenna respectively to receive each retransmission and measuring associated wireless communication quality. Additionally or alternatively, especially where the number of retransmissions per packet is limited (e.g., with voice communications), device 100 may carry out the process with successive packets of the sequence. For instance, the device may measure wireless performance using a second antenna for receipt of a retransmission of a successfully received first packet, and the device may measure wireless performance using a third antenna for receipt of a retransmission of a successfully received second packet, and so forth.

[0071] Conveniently, this use of an extraneous retransmission from device 102 as a basis for device 100 to evaluate wireless performance using another antenna would not require any special processing by device 102. This is because the process could make use of a normal acknowledgement and retransmission process at device 102. Namely, from the perspective of device 102, it may seem merely that device 100 did not successfully receive a packet, so device 102 would retransmit that packet as normal. This example implementation could therefore be provided as an advance in device 100, without a need to customize operation of device 102.

[0072] Note further that, with this implementation of causing extraneous retransmission, it may also be important for the device 100 to send an acknowledgement message in response to receiving the retransmission. Here, device 100 may be able to use this acknowledging of the retransmission in a further useful manner. For instance, if device 100 determines (e.g., through a CRC analysis) that it successfully received the retransmission, then device 100 could send an ACK to device 102 to let device 102 know that the transmission is complete. Further, if device 100 determines that it did not successfully receive the retransmission, then, given that device 100 had already successfully received the transmission using antenna 200, device 100 could just as well send an ACK to device 102 to let device 102 know that the transmission is complete. Still further, in either case, device 100 might alternatively respond to device 102 with another NACK in order to get another retransmissionfrom device 102 that would allow device 100 to further evaluate wireless performance using antenna 202. Other arrangements may be possible as well.

[0073] Figure 3 a message flow diagram illustrating how this process could work by way of example with the arrangement of Figure 2.

[0074] As shown in Figure 3, at step 300, device 100 uses antenna 200 to receive from device 102 a transmission of a packet (e.g., a BLE packet containing audio). At step 302, device 100 determines, by a CRC analysis for instance, that device 100 successfully received that packet. At step 304, notwithstanding its successful receipt of the packet, device 100 sends to device 102 a NACK for the packet, and device 100 switches from using antenna 200 to using antenna 202. At step 306, device 100 then uses antenna 202 to receive from device 102 a retransmission of the successfully received packet, and device 100 measures wireless performance as to that received retransmission using antenna 202. At step 308, device 100 then compares its measured wireless performance using antenna 202 with its measured wireless performance using antenna 200, as a basis to determine which of the antennas device 100 should use moving forward. And at step 310, device 100 proceeds to use the determined antenna for its communication with device 102.Use Extraneous Transmission of an Extra ACK as a Basis to Measure Wireless Performance Using Other Antenna

[0075] Another example of extraneous communication that can be added between device 100 and device 102 to facilitate device 100 measuring wireless communication quality using antenna 202 is an extra ACK from device 102 after device 102 has successfully received a packet wirelessly transmitted from device 100.

[0076] This example may apply in a scenario where device 100 wirelessly transmits to device 102 a sequence of packets and where device 102 and device 100 similarly use an acknowledgement and retransmission scheme to help ensure successful receipt of each packet by device 102.

[0077] For instance, this could apply with the BLE audio transmission process discussed above as to audio transmitted from device 100 to device 102, where, for each audio packet transmitted from device 101 to device 102, device 102 would either (i) determine, through a CRC analysis for instance, that it successfully received the packet and therefore send to device 100 an ACK, effectively indicating completion of that audio-packet transmission or (ii) determine, through a CRC analysis for instance, that it did not successfully receive thepacket and therefore send to device 100 a NACK or no acknowledgement, thereby causing device 100 to retransmit the packet from device 100 to device 102.

[0078] With this acknowledgment and retransmission scheme, the simple transmission of an ACK (typically a very small communication) from device 102 to device 100 may serve as a trigger for device 100 proceeding to transmit a next packet of the sequence (e.g., in a next isochronous interval). Therefore, in response to successful receipt of a packet from device 100, device 102 need not send anything further to device 100 beyond that ACK, as a basis to move the communication on to the next packet.

[0079] In accordance with the present example, however, when device 102 successfully receives a packet wirelessly transmitted from device 100, device 102 will not only send an ACK to device 100 as normal but will also then send another (extraneous) ACK to device 100, and device 100 could use that extraneous ACK transmission as a basis to measure wireless communication quality using antenna 202.

[0080] Accordingly, when device 100 is currently configured to use antenna 200, device 100 could transmit a packet to device 102 and could then receive from device 102 an ACK for that packet transmission. In response to receiving this ACK from device 102, device 100 could then (i) switch to use antenna 202 for purposes of receiving an additional, extraneous ACK from device 102 and (ii) using antenna 202, receive the extraneous ACK from device 102 and measure wireless performance of that received ACK transmission using antenna 202. Device 100 may then compare this wireless performance using antenna 202 with the device’s wireless performance using antenna 200, as a basis to control whether to use antenna 202 rather than antenna 200 moving forward.

[0081] In this process, if device 100 had recently determined wireless performance using antenna 200 before device 100 switched to use antenna 202 for receiving and measuring wireless performance of the extraneous ACK, then device 100 could use the wirelessperformance comparison as a basis to control whether to continue with use of antenna 202 or rather to switch back to use antenna 200. As with the retransmission implementation above, for instance, if device 100 thereby determines that the wireless performance using antenna 202 is better than the wireless performance using antenna 200, then, based on that determination, device 100 may continue to use antenna 202 rather than reverting to use antenna 200. Whereas, if device 100 thereby determines that the wireless performance using antenna 200 is better thanthe wireless performance using antenna 202, then, based on that determination, device 100 may revert to use antenna 200 rather than continuing to use antenna 202.

[0082] Alternatively, if device 100 had not recently determined wireless performance using antenna 200 before the device switched to use antenna 202 for receiving and measuring wireless performance of the extraneous ACK, then, upon switching back to use antenna 200 after measuring wireless performance of the extraneous ACK using antenna 202, device 100 could measure wireless performance using antenna 200 and could then perform the wireless-performance comparison as a basis to control which of antennas 200, 202 the device 100 should use moving forward. Likewise as with the retransmission implementation, if device 100 thereby determines that the wireless performance using antenna 202 is better than the wireless performance using antenna 200, then, based on that determination, device 100 may switch to use antenna 202 moving forward, rather than continuing to use antenna 200. Whereas, if device 100 thereby determines that the wireless performance using antenna 200 is better than the wireless performance using antenna 202, then, based on that determination, device 100 may continue to use antenna 200 rather than switching to use antenna 202.

[0083] This process could also be carried out analogously with more than two antennas. For instance, with three or more antennas, device 100 could measure wireless performance respectively using each other antenna, as to successive packets that device 100 transmits to device 102. For instance, device 100 could measure wireless performance using a second antenna for receipt of an extraneous ACK for a first transmitted packet, device 100 could measure wireless performance using a third antenna for receipt of an extraneous ACK for a second transmitted packet, and so forth.

[0084] Note that, in contrast with the retransmission implementation described above, this extraneous-ACK implementation involves special processing by device 102. Namely, device 102 would need to be configured to send the extraneous ACK to device 100 after first sending an ACK to the device. If device 100 and device 102 are in a common ecosystem (e.g., of a common brand), then both devices may be configured to support this. Alternatively, in other scenarios as well, device 100 and device 102 may each be configured to support this.

[0085] Further, this process could likewise be carried out in response to a time trigger, such as periodically with a period on the order of tens of packets or hundreds of packets, among other possibilities, and / or in response to one or more other agreed triggers. Among other possibilities, for instance, device 100 and device 102 may agree on a schedule or plan to carryout the process, such as when the device and other wireless endpoint start communicating with each other (e.g., as part of ACL signaling to configure their data communication), or perhaps by including a flag in a packet-specific header or other signal that indicates the process will occur.

[0086] As a specific example, when device 100 is set to use antenna 200 and when device 102 is going to send to device 100 an extraneous ACK that would enable device 100 to measure wireless performance using antenna 202, device 102 may include in or with its normally transmitted ACK to device 100 a bit or other information that device 100 could interpret as an indication that device 102 is going to do so. In response to that indication, device 100 could then switch over to antenna 202 to receive and measure wireless performance of the extraneous ACK transmission using antenna 202.

[0087] As another example, when device 100 is set to use antenna 200, device 100 may be able to cause device 102 to send an extraneous ACK to device 100 for present purposes, by including a directive with the packet transmission to device 102. For instance, device 100 may include in a header of its packet transmission to device 102 a bit or other information that device 102 could interpret as a directive for device 102 to engage in this process. Given this directive, after device 102 then sends a normal ACK to device 100, device 100 could switch to antenna 202, device 102 could send an extraneous ACK to device 100, and device 100 could measure wireless performance of that extraneous ACK transmission using antenna 202.

[0088] Likewise, device 100 could carry out this analysis based on a running average over a recent sliding window of measurements. For instance, as with the example above, device 100 could use this process as a basis to take multiple measurements over time of wireless performance using antenna 200 and multiple measurements over time of wireless performance using antenna 202, and device 100 could compare a running average of wireless performance using antenna 200 with a running average of wireless performance using antenna 202, as a basis to control which of the antennas to have device 100 use moving forward.

[0089] Still further, in some variations of this example, the extraneous signaling from device 102 could be something other than an extraneous ACK. Other signaling examples may include, without limitation, (i) an extraneous NACK following the normal ACK, (ii) a null packet following the normal ACK, or (iii) any other agreed signal or signal of agreed duration following the normal ACK. Largely any signal of a form or duration that device 100 and device 102 agree to use can be used for this purpose. Further, in still other variations, largely the sameprocess could be carried out with timing different than being right after a normally transmitted ACK.

[0090] Figure 4 a message flow diagram illustrating how this process could work by way of example with the arrangement of Figure 2.

[0091] As shown in Figure 4, at step 400, device 100 uses antenna 200 to transmit a packet (e.g., a BLE audio packet) to device 102. At step 402, device 100 then receives from device 102 an ACK for the packet, which confirms that device 102 successfully received the packet. At step 404, device 100 switches from antenna 200 to antenna 202 to measure performance of an extraneous ACK from device 102. At step 406, device 100 then uses antenna 202 to receive from device 102 an extraneous ACK for the packet, and device 100 measures wireless performance as to that received extraneous ACK using antenna 202. At step 408, device 100 then compares its measured wireless performance using antenna 202 with its measured wireless performance using antenna 200, as a basis to determine which of the antennas device 100 should use moving forward. And at step 410, device 100 proceeds to use the determined antenna for its communication with device 102.Use of Control-Link Communication as a Basis to Measure Wireless Performance Using Another Antenna Without Switching Data-Link to Other Antenna

[0092] Another implementation as noted above involves using a wireless control link as a basis to monitor wireless performance per antenna without switching data link communication from one antenna to another. Without limitation, this implementation may be particularly useful in a scenario where data being communicated between the device and the other wireless endpoint is especially sensitive to issues that may result from antenna switching. Examples of such a scenario include Bluetooth communication of voice using hands-free profile noted above, possibly with BLE audio for instance.

[0093] In the example scenario, device 100 and device 102 may have co-existing, established links separately for control and data communication, namely, a control link and a data link. As noted above, for instance, the control link may be an ACL link, and the data link may be a configured CIG comprising one more CISs. Alternatively, the control link may be an ACL link, and the data link may be an enhanced synchronous connection oriented (eSCO) link. As with the implementations above, other examples may be possible, including examples unrelated to Bluetooth communication.

[0094] The control link may carry control-plane communications, such as null packets to maintain synchronization, a channel map to facilitate adaptive frequency hopping,and power-control signaling to control transmission power based on receive signal strength, among other possibilities. The data link, on the other hand, may carry user-plane communications, such as digitized audio, among other possibilities.

[0095] If device 100 uses just a single antenna at a time, communication on these links may be time-division multiplexed, with an agreed frame structure that defines time intervals when the data link would exist and time intervals when the control link would exist. (For example, with BLE audio on a configured CIG and with a co-existing ACL link, timing could be coordinated between the CIG and ACL such that ACL control communication could occur at predefined time intervals when CIG data communication would not be occurring, and vice versa.) Thus, over time, there may be separately defined control-link time intervals and data-link time intervals.

[0096] In example implementations, the control link may be more robust than the data link. For instance, communication on the control link may use a lower data rate with a lower-order modulation scheme than communication on the data link, which may make the control link less sensitive to problems with wireless performance. In particular, if the control link uses a lower-order modulation scheme than the data link, interference or other problems on the wireless communication path between the device and the other wireless endpoint may be less likely to adversely impact communication on the control link than communication on the data link. Thus, with relatively poor wireless performance, device 100 may still be able to successfully receive control -link communication from device 102, whereas device 100 may be unable to successfully receive data-link communication from device 102.

[0097] In accordance with the present example, device 100 could switch the control link from antenna to antenna to facilitate measuring wireless performance per antenna, while keeping the data link on a given antenna.

[0098] For instance, while device 100 is configured to use antenna 200 for data-link communication with device 102, device 100 could switch its control -link communication between antennas 200 and 202 and could measure respective wireless performance (e.g., receive-signal strength, SNR, or SINR) of the control-link communication per antenna. Device 100 may thus compare its measured wireless performance of the control -link communication using antenna 200 with its measured wireless performance of the control-link communicationusing antenna 202, as a basis to control whether to have its data-link communication use antenna 200 or rather antenna 202 moving forward.

[0099] If device 100 thereby determines based on its monitoring of wireless performance of the control-link communication per antenna that the wireless performance is better using antenna 200 than using antenna 202, then, based on this determination, device 100 could continue to use antenna 200 for its data-link communication. Whereas, if device 100 thereby determines based on its monitoring of wireless performance of the control-link communication per antenna that the wireless performance is better using antenna 202 than using antenna 200, then based on this determination, device 100 could switch to use of antenna 202 for its data-link communication.

[0100] Accordingly, with this implementation, as device 100 is set to use antenna 200 for its data-link communication, device 100 could retain its use of antenna 200 for each data-link interval unless and until device 100 determines by monitoring wireless performance of control-link communication in one or more control-link intervals that wireless performance using antenna 202 is better than wireless performance using antenna 200 - at which point device 100 could then switch to use antenna 202 for its data-link intervals moving forward (and conveniently also use antenna 202 for its control-link intervals moving forward).

[0101] In an example implementation, device 100 could maintain a running average of wireless performance of the control-link communication per antenna, based on instances of device 100 measuring wireless performance of the control -link communication per antenna. For instance, device 100 may alternate between using antenna 200 and antenna 202 on a per- control-link-interval basis or with some other timing, device 100 may make successive measurements of wireless performance of the control-link communication per antenna, device 100 may maintain a per-antenna running average. Device 100 may then further compare its running average of wireless performance of the control-link communication using antenna 200 with its running average of wireless performance of the control-link communication using antenna 202, as a basis to control which antenna device 100 should use for the data-link communication moving forward.

[0102] As with the implementations discussed above, device 100 may use various triggers to control how often to switch between antennas for measuring wireless performance of control -link communication per antenna. For instance, device 100 could carry out the process in response to a time trigger, such as by switching between antennas at each successive control-link interval, switching between antennas during control-link intervals, or switchingbetween antennas periodically with a period on the order of tens or hundreds of control-link intervals, among other possibilities.

[0103] Further, device 100 could likewise carry out the process in response to an evaluation of operational state. For instance, device 100 could keep its control-link communication on antenna 200 and switch the control-link communication to antenna 202 to test wireless performance using antenna 202 in response to (i) determining that wireless performance of the control-link communication using antenna 200 is at least as poor as a predefined low-quality threshold, and / or (ii) in response to determining that battery energy of device 100 (if applicable) is at least as low as a predefined threshold level, among other possibilities.

[0104] Still further, as with the implementations discussed above, this process could also be carried out with more than two antennas. For instance, with three or more antennas, device 10 could measure wireless performance of control-link communication respectively using each other antenna, such as by testing wireless performance of control-link communication using a first antenna, then testing wireless performance of control-link communication using a second antenna, then testing wireless performance of control-link communication using a third antenna, and so forth, all while retaining data-link communication through one antenna to help avoid interruption of data communication.

[0105] As with the extraneous-NACK retransmission implementation discussed above, this implementation also conveniently would not require any special processing by device 102. Device 100 could thus switch between its antennas to test wireless performance of control -link communication from device 102 on a per-antenna basis without device 102 being aware that device 100 is doing so.Example Process Flow

[0106] Figure 5 is next a flow chart illustrating an example method to control antenna use by a wireless communication device (WCD) that has multiple antennas including a first antenna and a second antenna and that is configured to use just one of the antennas of the plurality antennas at a time to wirelessly communicate using a particular wireless radio access technology.

[0107] As shown in Figure 5, at block 500, the method includes the WCD using the first antenna to receive active baseline wireless communication directly from another device using the particular wireless radio access technology, and the WCD measuring wireless performance of the active baseline wireless communication received via the first antenna. Atblock 502 (which may occur before or after block 500), the method includes the WCD switching from using the first antenna to using the second antenna to receive directly from the other device an extraneous wireless communication, and the WCD measuring wireless performance of the extraneous wireless communication received via the second antenna. At block 504, the method then includes the WCD comparing the measured wireless performance of the active baseline wireless communication received via the first antenna with the measured wireless performance of the extraneous wireless communication received via the second antenna. And at block 506, the method includes the WCD controlling, based on the comparison, whether to selectively change to active baseline wireless communication with the other device using the particular wireless radio access technology via the second antenna.

[0108] For instance, the extraneous communication in this method could comprise an extraneous data retransmission. And in that case, the method could involve the WCD successfully receiving from the other device a transmission of a packet, and, in response to the successful receiving of the packet, the WCD negatively acknowledging the packet as a trigger for the other device to retransmit the packet to the WCD. (For instance, the WCD could send to the other device an express NACK of the packet, possibly after first switching to use the second antenna, or the device could implicitly negatively acknowledge the packet by forgoing positively acknowledging the packet.) Accordingly, the extraneous data retransmission could include the triggered retransmission of the packet from the other device to the WCD.

[0109] Alternatively, the extraneous communication in this method could comprise an extraneous ACK. And in that case, the method could involve the WCD transmitting to the other device a packet, the WCD receiving from the other device an active baseline ACK that indicates successful receipt of the packet by the other device, and the WCD thereafter receiving the extraneous ACK from the other device, the extraneous ACK also indicating successful receipt of the packet by the other device. Further, the WCD could also detect a signal from the other device indicating that the other device is going to transmit the extraneous ACK, and the WCD’s switching, comparing, and controlling could be responsive to at least that detecting.

[0110] As further discussed above, the method could also involve the WCD determining that the measured performance of the baseline wireless communication using the first antenna is at least as poor as a predefined poor-quality threshold. And in this case, theWCD’s switching, comparing, and controlling could be responsive to at least that determination.

[0111] Further, as noted above, the method could involve the WCD periodically carrying out the using, switching, comparing, and controlling operations.Example Device Architecture

[0112] Figure 6 is a simplified block diagram illustrating components of an example wireless communication device, which may represent device 100 or device 102, among other possibilities.

[0113] As shown in Figure 6, the example device includes host processor 600, non- transitory system data storage 602, and a wireless communication interface 604. These components could be integrated together and / or communicatively linked together in various ways. For instance, the components could be linked together through a system bus, network, or other connection mechanism 606. Alternatively, various integrations and other arrangements may be possible.

[0114] The host processor 600 may comprise one or more general purpose processors (e.g., microprocessors) and / or one or more special purpose processors (e.g., DSPs). Further, the non-transitory system data storage 602 may comprise one or more volatile and / or non-volatile storage components (e.g., optical, magnetic, or flash storage, RAM, ROM, EPROM, EEPROM, cache memory, and / or other computer-readable media, etc.), possibly integrated in whole or in part with the host processor 600. As shown, the non-transitory system data storage 602 may then store program instructions 608, which may be executable by the host processor 600 to carry out various host operations. For instance, the host processor 600 may execute these instructions to generate data for transmission by the wireless communication interface 604 and / or to process data received by the wireless communication interface 604.

[0115] The wireless communication interface 604 may then comprise components such as those noted above, to support wireless communication between the device and one or more other devices. As shown more generally by Figure 6, the wireless communication interface 604 may comprise a processor 610, non-transitory data storage 612, a radio 614, an RFFE 616, an antenna switch 618, and multiple antennas 620.

[0116] In an example implementation, the non-transitory data storage 612 of the wireless communication interface 604 may store program instructions 622 executable by the processor 610 of the wireless communication interface to cause the example device to carryout various operations discussed herein, such as to carry out the method of Figure 5 for instance. Further, the other components could operate as discussed above, among other possibilities.

[0117] In addition, the present disclosure also contemplates a non-transitory computer-readable medium (e.g., optical, magnetic, or flash storage, RAM, ROM, EPROM, EEPROM, etc.) having stored thereon program instructions executable by a processor of a device to cause the device to carry out various operations described herein.

[0118] While the above description describes a device evaluating wireless performance on a second antenna by making use of extraneous communication and / or control link communication between the device and another device, note that other arrangements could be possible as well. Without limitation, for instance, if a device has information about when other nearby devices will be engaging in wireless communication with each other, the device may be able to monitor wireless performance per antenna by switching between antennas and detecting and measuring quality with respect to the wireless communication between those other devices.

[0119] Example embodiments have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to these embodiments without departing from the true scope and spirit of the invention.

Claims

CLAIMSWhat is claimed is:

1. A method to control antenna use by a wireless communication device (WCD), wherein the WCD has a plurality of antennas including a first antenna and a second antenna, and wherein the WCD is configured to use just one of the antennas of the plurality antennas at a time to wirelessly communicate using a particular wireless radio access technology, the method comprising: using, by the WCD, the first antenna to receive active baseline wireless communication directly from another device using the particular wireless radio access technology, and measuring, by the WCD, wireless performance of the active baseline wireless communication received via the first antenna; switching, by the WCD, from using the first antenna to using the second antenna to receive directly from the other device an extraneous wireless communication using the particular wireless radio access technology, and measuring, by the WCD, wireless performance of the extraneous wireless communication received via the second antenna; comparing, by the WCD, the measured wireless performance of the active baseline wireless communication received via the first antenna with the measured wireless performance of the extraneous wireless communication received via the second antenna; and controlling, by the WCD, based on the comparing, whether to selectively change to active baseline wireless communication with the other device using the particular wireless radio access technology via the second antenna.

2. The method of claim 1, wherein the extraneous wireless communication comprises a communication selected from the group consisting of an extraneous data retransmission and an extraneous positive-acknowledgement (ACK).

3. The method of claim 2, wherein the extraneous wireless communication comprises the extraneous data retransmission, the method further comprising: successfully receiving by the WCD from the other device a transmission of a packet; andresponsive to the successfully receiving of the packet, the WCD negatively acknowledging the packet as a trigger for the other device to retransmit the packet to the WCD, wherein the extraneous data retransmission comprises the triggered retransmission of the packet from the other device to the WCD.

4. The method of claim 3, wherein negatively acknowledging the packet comprises expressly sending to the other device a negative acknowledgement (NACK) of the packet.

5. The method of claim 4, wherein the switching from using the first antenna to using the second antenna is also to transmit to the other device the NACK responsive to the successfully receiving of the packet.

6. The method of claim 2, wherein the extraneous wireless communication comprises the extraneous ACK, the method further comprising: transmitting by the WCD to the other device a packet; and receiving by the WCD from the other device an active baseline ACK indicating successful receipt of the packet by the other device, wherein the WCD receives the extraneous ACK from the other device after receiving the active baseline ACK from the other device, and wherein the extraneous ACK also indicates successful receipt of the packet by the other device.

7. The method of claim 6, further comprising: detecting, by the WCD, a signal from the other device indicating that the other device is going to transmit the extraneous ACK, wherein the switching, comparing, and controlling are responsive to at least the detecting.

8. The method of claim 2, further comprising determining by the WCD that the measured performance of the active baseline wireless communication received via the first antenna is at least as poor as a predefined poor-quality threshold, wherein the switching, comparing, and controlling are responsive to at least the determining that the measured performance of the active baseline wireless communication received via the first antenna is at least as poor as the predefined poor-quality threshold.

9. The method of claim 2, further comprising periodically carrying out the using, switching, comparing, and controlling.

10. A wireless communication device (WCD) comprising: a plurality of antennas including a first antenna and a second antenna, wherein the WCD is configured to use just one of the antennas of the plurality antennas at a time to wirelessly communicate using a particular wireless radio access technology; a processor; non-transitory data storage; and program instructions stored in the non-transitory data storage and executable by the processor to cause the device to carry out operations including: using the first antenna to receive active baseline wireless communication directly from another device using the particular wireless radio access technology, and measuring, by the WCD, wireless performance of the active baseline wireless communication received via the first antenna, switching from using the first antenna to using the second antenna to receive directly from the other device an extraneous wireless communication using the particular wireless radio access technology, and measuring, by the WCD, wireless performance of the extraneous wireless communication received via the second antenna, comparing the measured wireless performance of the active baseline wireless communication received via the first antenna with the measured wireless performance of the extraneous wireless communication received via the second antenna, and controlling, based on the comparing, whether to selectively change to active baseline wireless communication with the other device using the particular wireless radio access technology via the second antenna.

11. The WCD of claim 10, wherein the extraneous wireless communication comprises a communication selected from the group consisting of an extraneous data retransmission and an extraneous positive-acknowledgement (ACK).

12. The WCD of claim 11, wherein the extraneous wireless communication comprises the extraneous data retransmission, the method further comprising: successfully receiving by the WCD from the other device a transmission of a packet; and responsive to the successfully receiving of the packet, the WCD negatively acknowledging the packet as a trigger for the other device to retransmit the packet to the WCD, wherein the extraneous data retransmission comprises the triggered retransmission of the packet from the other device to the WCD.

13. The WCD of claim 12, wherein negatively acknowledging the packet comprises expressly sending to the other device a negative acknowledgement (NACK) of the packet.

14. The WCD of claim 13, wherein the switching from using the first antenna to using the second antenna is also to transmit to the other device the NACK responsive to the successfully receiving of the packet.

15. The WCD of claim 11, wherein the extraneous wireless communication comprises the extraneous ACK, the method further comprising: transmitting by the WCD to the other device a packet; and receiving by the WCD from the other device an active baseline ACK indicating successful receipt of the packet by the other device, wherein the WCD receives the extraneous ACK from the other device after receiving the active baseline ACK from the other device, and wherein the extraneous ACK also indicates successful receipt of the packet by the other device.

16. The WCD of claim 15, wherein the operations additionally include: detecting a signal from the other device indicating that the other device is going to transmit the extraneous ACK, wherein the switching, comparing, and controlling are responsive to at least the detecting.

17. The WCD of claim 11, wherein the operations additionally include determining that the measured performance of the active baseline wireless communication using the first antenna is at least as poor as a predefined poor-quality threshold,wherein the switching, comparing, and controlling are responsive to at least the determining that the measured performance of the active baseline wireless communication using the first antenna is at least as poor as the predefined poor-quality threshold.

18. The WCD of claim 11, wherein the operations include periodically carrying out the using, switching, comparing, and controlling.

19. A non-transitory computer-readable medium having stored thereon program instructions executable by a processor of a wireless communication device (WCD) to cause the WCD to carry out operations for controlling antenna use by the WCD, wherein the WCD has a plurality of antennas including a first antenna and a second antenna, and wherein the WCD is configured to use just one of the antennas of the plurality antennas at a time to wirelessly communicate using a particular wireless radio access technology, the operations comprising: using the first antenna to receive active baseline wireless communication directly from another device using the particular wireless radio access technology, and measuring, by the WCD, wireless performance of the active baseline wireless communication received via the first antenna; switching from using the first antenna to using the second antenna to receive directly from the other device an extraneous wireless communication using the particular wireless radio access technology, and measuring, by the WCD, wireless performance of the extraneous wireless communication received via the second antenna; comparing the measured wireless performance of the active baseline wireless communication received via the first antenna with the measured wireless performance of the extraneous wireless communication received via the second antenna; and controlling, based on the comparing, whether to selectively change to active baseline wireless communication with the other device using the particular wireless radio access technology via the second antenna.

20. The non-transitory computer-readable medium of claim 19, wherein the extraneous wireless communication comprises a communication selected from the group consisting of an extraneous data retransmission and an extraneous positive-acknowledgement (ACK).

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