Mobile hybrid radio receiver service after source selection

Abstract

A method is disclosed comprising receiving, at a hybrid radio receiver configured to recover audio content from a broadcast radio signal and from a wireless network connection separately, a reception metric indicative of an audio quality of the audio content in the broadcast radio signal at any given time. The method further comprises deriving, from fluctuations in the reception metric over time, a fluctuation indicator indicative of fluctuations in the audio quality likely to be noticed by a listener. The method further comprises deriving, based on a previous switching decision and the fluctuation indicator, a switching decision to use the broadcast radio signal or the wireless network connection as a source of the audio content to introduce a hysteresis into the switching decision, and selecting, based on the switching decision, the broadcast radio signal or the wireless network connection as the source of the audio content.

Description

[0001] Priority Statement

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 079,463, filed September 16, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to recovering audio content via a hybrid radio receiver. Background Technology

[0004] Mobile hybrid radio receivers can recover streaming audio content from broadcast radio signals and wireless network signals via Internet Protocol (IP) connections (e.g., wireless IP connections). The movement of a hybrid radio receiver alters radio frequency (RF) reception conditions. Under such conditions, a hybrid radio receiver may switch its audio source from broadcast radio signals to a wireless IP connection, incurring significant network service costs and, if the decision on when to switch is inappropriate, resulting in poor audio quality from the listener's perspective. Hybrid radio receivers can employ conventional switching techniques to determine when to switch to an IP connection. One technique involves monitoring the Received Signal Strength Indicator (RSSI) of the broadcast radio signal, or deriving what is essentially an equivalent RSSI based on the hybrid radio receiver's known geographic location, and switching to an IP connection when the RSSI indicator drops below a single threshold. The fact that RSSI is an indirect indicator of audio quality and relies on a single threshold leads to coarse, often poor, switching decisions that can be either too aggressive (i.e., too fast) or too sluggish (i.e., too slow). Consequently, users / listeners experience poor audio quality and increased network service costs.

[0005] Another technique involves comparing the location of the hybrid radio receiver to predetermined geographic coordinates representing the boundaries of a geofence, and triggering a handover to an IP connection based on this comparison. This technique can also produce suboptimal handover decisions because it does not take into account the actual reception conditions experienced by the hybrid radio receiver or the varying reception performance associated with different types of hybrid radio receivers. Therefore, using geofences as the basis for handover decisions leads to poor audio quality and increased network service costs. Attached Figure Description

[0006] Figure 1 This is a high-level block diagram of an example hybrid radio system.

[0007] Figure 2 This is a block diagram of an example hybrid radio receiver of a radio system according to embodiments presented herein, which implements a switching algorithm to derive a switching decision using either a broadcast radio signal or a wireless network connection as the source of audio content.

[0008] Figure 3 This is a flowchart of an example of a switching algorithm that derives a switching decision based on a reception metric indicating the audio quality associated with a broadcast radio signal.

[0009] Figure 4 This is a flowchart of an example of a switching algorithm.

[0010] Figure 5 This is a flowchart of another example of a switching algorithm. Detailed Implementation

[0011] Example embodiments

[0012] The embodiments described herein can be implemented in a hybrid radio receiver capable of rendering audio (e.g., audio playback) and metadata obtained from multiple over-the-air (OTA) or wireless sources—including broadcast radio power sources (e.g., broadcast radio signals) and wireless network sources (e.g., wireless IP connections). RF reception conditions can vary significantly due to signal strength, adjacent channel interference levels, and multipath interference as the hybrid radio receiver changes location. Therefore, it is important for the hybrid radio receiver to know which OTA source to select for audio and metadata at any given time to obtain the best user listening experience at the lowest cost. While streaming audio and metadata recovered from broadcast radio signals (such as analog FM radio signals) is free for the user, data charges apply, for example, when streaming audio and metadata from an IP connection via a cellular data modem. Furthermore, radio broadcasters can generate substantial royalties from providing streaming services via IP connections and are therefore incentivized to ensure users use broadcast radio signals rather than IP connections whenever possible.

[0013] Therefore, the embodiments presented herein include a handover algorithm configured to generate a handover or source decision to use either a broadcast radio signal or a wireless IP connection as the “best” source from which audio and metadata are obtained based on an audio quality metric (also referred to as the “metric” in the following description) derived from or indicating audio quality from the broadcast radio signal. Field testing shows that the handover decision is highly correlated with results obtained through subjective evaluation of audio captured during field mobile testing (e.g., car driving tests). The handover algorithm ensures that a broadcast radio signal, rather than an IP connection, is selected as the audio source when the audio quality is good according to the criteria established by the handover algorithm, thereby meeting the expectation of minimizing IP data usage from both the user’s and broadcast cost perspectives.

[0014] The metrics processed by the switching algorithm to provide switching decisions are readily available from or easily derived from the integrated circuits (ICs) of most modern automotive FM radio tuners. Such ICs calculate and provide one or more metrics to control internal audio soft mute and high cut. This metric reflects or indicates the level of unwanted, rapidly changing audio fluctuations, which can be caused by, for example, multipath interference, and are perceptible to the listener. At a high level, the switching algorithm counts the corresponding number of times the metric crosses each of two spaced thresholds within a predetermined time period. The switching algorithm calculates / determines a fluctuation indicator based on the individual span counts, and then provides a switching or source decision based on the metric fluctuation indicator to use or broadcast radio signals or wireless network connections as the source of audio and metadata. Subjective listening tests on various car driving routes in the field show that the switching decisions produced by the switching algorithm closely match human auditory preferences. This is because human hearing is sensitive to changes in audio quality, and the switching algorithm essentially counts fluctuations between good and bad audio quality.

[0015] Advantageously, switch algorithms:

[0016] a. Implemented as a low-cost solution in hybrid radio receivers.

[0017] b. Direct measurements of audio quality based on the user’s actual perception are indirect and therefore often inaccurate compared to Received Signal Strength Indicator (RSSI) values.

[0018] c. Automatically adapts to various types of hybrid radio receivers and vehicle mounting performance, so that in high-quality radio receivers with high-performance antenna systems, the switching algorithm does not switch away too aggressively from the high-quality audio recovered from the broadcast radio signal.

[0019] d. By simply adjusting a few simple threshold and time interval parameters, the radical adjustment of IP connectivity relative to broadcast radio power selection can be directly provided. Therefore, for radio broadcasters, providing radical settings for their (one or more) broadcast radio stations via IP connectivity is a direct extension.

[0020] e. The implementation of the handover algorithm in the hybrid radio receiver is suitable for direct testing / evaluation by generating a test RF signal and directly evaluating the handover decision; location information is not required.

[0021] refer to Figure 1This is a high-level block diagram of an example radio system 100. Radio system 100 includes a radio station 102 transmitting broadcast radio signals (equivalently referred to as radio broadcast signals), a network system 106 transmitting wireless network signals via a wireless network connection, and a mobile / portable hybrid radio receiver (Rx) 110 configured to implement a switching algorithm according to embodiments presented herein. In one example, the broadcast radio signal may include a conventional analog FM radio signal. In another example, the broadcast radio signal may include an analog amplitude modulation (AM) radio signal. The broadcast radio signal transmits / carries audio content to the hybrid radio receiver 110. The audio content includes audio and may or may not include metadata such as text, timing information, and / or images. For example, the audio content may include streamed audio with metadata embedded in the audio.

[0022] Network system 106 includes a communication network 112, which is communicatively coupled to a network transmitter (Tx) 114 to transmit wireless network signals. The communication network 112 may include one or more wide area networks (WANs) (such as the Internet), and one or more local area networks (LANs), content production networks, cellular networks, WiFi networks, etc. Examples of network transmitters 114 may include cellular towers associated with cellular networks, or devices conforming to the IEEE 802.11 protocol suite (e.g., The network transmitter 114 receives network data in the form of data packets from the communication network 112. The network transmitter 114 transmits wireless network signals (e.g., cellular or WiFi signals) including data packets to the hybrid radio receiver 110, typically via a wireless network connection (e.g., a wireless IP connection) with the hybrid radio receiver. The wireless network signals may carry / transmit the same or different audio content as that transmitted by the broadcast radio signals. Furthermore, the network transmitter 114 and the radio broadcast station 102 can concurrently transmit their respective OTA signals and audio content.

[0023] The hybrid radio receiver 110 implements a switching algorithm. Based on the aforementioned metrics, the hybrid radio receiver 110 applies the switching algorithm to both broadcast radio signals and wireless network signals (collectively referred to as "OTA received signals") to select one of the OTA received signals as the source of the audio content. The following will combine... Figures 3-5 Describe the switching algorithm in detail.

[0024] Figure 2This is a functional block diagram of a portion of a hybrid radio receiver 110 according to an embodiment. The hybrid radio receiver 110 includes a radio broadcast receiver 202, a wireless network radio device 204 (e.g., IP radio), a source selector or switch 206, and a receiver controller (also simply referred to as the "controller") 210, all of which are communicatively coupled to each other. A portion of the radio broadcast receiver 202, a portion of the wireless network radio device 204, and the source selector 206 may be incorporated into the controller 210.

[0025] Radio receiver 202 includes antenna 211, RF tuner 212, combined analog-to-digital converter (ADC) / downconverter 214, demodulator 216, and metric derivatizer 218. Antenna 211 delivers broadcast radio signals received by the antenna to RF tuner 212. The broadcast radio signals carry / transmit audio content, including audio and metadata, or just audio. RF tuner 212 tunes to the desired RF channel of the broadcast radio signal, downconverts the RF channel into an intermediate frequency (IF) signal, and provides the IF signal to ADC / downconverter 214. ADC / downconverter 214 digitizes the IF signal and downconverts it into a digitized baseband signal, and provides the baseband signal to demodulator 216.

[0026] Demodulator 216 demodulates the baseband signal into audio content 222 and delivers the audio content to source selector 206. Demodulator 216 can also directly provide any metadata included in the audio content 222 to controller 210. Examples of demodulator 216 include FM demodulators for demodulating FM radio broadcast signals and AM demodulators for demodulating analog AM radio broadcast signals. In summary, radio receiver 202 is configured to recover the audio content carried / transmitted by the broadcast radio signal to produce audio content 222.

[0027] The metric derivator 218 includes circuitry / logic configured to derive a received metric P from / based on a broadcast radio signal. The metric derivator 218 can be integrated with tuner 212, ADC / downconverter 214, and / or demodulator 216 to derive the audio quality metric P from the RF, IF, baseband signals, and / or demodulated audio, respectively. For example, when integrated with or located after demodulator 216, the metric derivator 218 can derive or measure the metric P directly from the audio content 222.

[0028] Measure P indicates, or is related to, the audio quality of the audio content 222 given to the listener at any given time. Measure P can represent an unprocessed and unweighted measurement of audio quality. The time-varying or time-dependent (i.e., dynamic) fluctuation of Measure P accordingly indicates fluctuations in audio quality. When sufficiently large, the quantity and magnitude of the dynamic fluctuation of Measure P over time correspondingly indicate audio quality fluctuations that may attract the listener's attention and annoy them. Thus, Measure P can represent unwanted levels or amplitude fluctuations in a broadcast radio signal (e.g., an FM broadcast radio signal) that are not present in the originally transmitted broadcast radio signal and translate into fluctuations in audio quality. For example, unwanted fluctuations can be caused by multipath conditions in the environment. Therefore, Measure P can be referred to as a multipath metric or indicator. In summary, the dynamic fluctuation of Measure P can be considered as indicating a deterioration in audio quality for the listener.

[0029] In the example, metric derivative 218 may include a wideband AM detector that captures rapidly changing level fluctuations in the envelope of the FM modulation of a broadcast radio signal with a granularity of approximately 1 or 2 milliseconds (ms). Radio receiver 202 provides access to metric P to controller 210 via an interface between the controller and the radio receiver.

[0030] Network radio device 204 includes antenna 230, wireless network interface (I / F) 232, and packet processor 234. Wireless network I / F 232 establishes a bidirectional wireless network connection (e.g., IP connection, or other type of data connection) with a communication network via antenna 230. For example, wireless network I / F 232 may include Wi-Fi interface components and / or cellular interface components for transmitting and receiving wireless RF signals. In the receiving direction, wireless network I / F 232 receives data packets encoded with audio content (e.g., audio and metadata) from the communication network and passes the data packets to packet processor 234. Packet processor 234 decodes the data packets to recover the audio content (represented at 239). Packet processor provides the audio content 239 to source selector 206 and may directly provide any metadata in the audio content to controller 210. In the transmitting direction, network radio device 204 wirelessly transmits data packets to the communication network.

[0031] In this embodiment, network radio device 204 monitors / determines the integrity or quality of the wireless network connection and provides an indicator or metric (referred to as a wireless network connection quality indicator) to controller 210, indicating whether the quality of the wireless network connection is good / acceptable (e.g., within connection quality constraints) or poor / unacceptable (e.g., outside quality constraints). Network radio device 204 may use any known or later-developed techniques to monitor the quality of the wireless network connection, including determining whether the rate of lost data packets is within quality constraints, whether data packet decoding errors are within quality constraints, whether the RSSI of the wireless network signal is within quality constraints, and so on.

[0032] Source selector 206 receives a switching signal SW(k) from controller 210. Controller 210 derives the switching signal SW(k) based on a switching algorithm, as described below. Based on the state of the switching signal SW(k), source selector 206 selects either audio content 222 recovered from a broadcast radio signal by radio receiver 202 or audio content 239 recovered from a wireless network connection by network radio device 204 as output audio content 250. Source selector 206 can provide the audio of output audio content 250 to an audio output interface or device (…). Figure 2 (Not shown in the image) (such as an audio port or speaker) to be played back to the audience.

[0033] Controller 210 controls radio broadcast receiver 202 and network radio device 204, and in this embodiment, is primarily responsible for implementing the switching algorithm. Controller 210 is coupled to and communicates with radio broadcast receiver 202 and network radio device 204 via corresponding interfaces to the radio broadcast receiver and network radio device 204. Controller 210 includes one or more processors 260 and memory 262. Memory 262 stores control software 264 (referred to as “control logic”) that, when executed by processors 260, causes processors 260, and more generally, controller 210, to perform the various operations described herein for hybrid radio receiver 110. Processors 260 may be microprocessors or microcontrollers (or multiple instances of such components). Memory 262 may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physically tangible (i.e., non-transitory) memory storage devices. Controller 210 may also be discrete logic embedded in an IC device.

[0034] Therefore, in general, memory 262 may include one or more tangible (non-transitory) computer-readable storage media (e.g., one or more memory devices) encoded with software or firmware including computer-executable instructions. For example, control software 264 includes logic for implementing the operation of a switching algorithm performed by controller 210 and more generally by hybrid radio receiver 110. Thus, control software 264 implements the various methods / operations described herein.

[0035] In addition, memory 262 stores data 266 used and generated by control software 264.

[0036] Figure 3 This is a flowchart of an example switching algorithm 300 (also referred to simply as the "algorithm") that can be implemented by controller 210. At a high level, the algorithm periodically reads or collects input values ​​or samples of metric P from radio broadcast receiver 202 at regular intervals (such as every 100 ms). The algorithm can use intervals less than or greater than 100 ms. The algorithm repeatedly operates on each "current" value of the collected metric P to derive a switching decision for each value, using a broadcast radio signal or wireless network signal / wireless network connection as the source of audio corresponding to the current value. Thus, these operations represent operations for each value or each interval, which derive a switching decision on a value / each interval basis.

[0037] For example, the algorithm (i) collects a first value of metric P and processes the first value during the first pass operation to derive a first switching decision corresponding to the first value, (ii) collects a second value of metric P and processes the second value during the second pass operation to derive a second switching decision corresponding to the second value, and so on. In the example above, when the second pass operation is referred to as the "current" pass or iteration, the first pass is referred to as the "previous" pass or iteration.

[0038] In each "current" iteration, the algorithm derives the current handover decision based on (i) the current value of metric P, (ii) multiple previous values ​​of that metric, and (iii) previous handover decisions. Deriving the current handover decision based on the current value, previous values, and previous handover decisions introduces a lag into the handover decision, which helps avoid overly aggressive handovers between broadcast radio signals and wireless network connections as sources of audio content, given the different RF reception conditions.

[0039] The algorithm will now be described in detail. At 302, the algorithm initialization is performed by the algorithm and... Figure 3 The variables described in the table below. Various variables and their example initializations / default values ​​are introduced in Table 1 below.

[0040]

[0041]

[0042] Table 1

[0043] At 304, the algorithm receives or collects a new / current value x(k) of metric P from radio receiver 202, where k indicates the current iteration of the algorithm that derives the current switching decision D(k) using the value x(k) based on previous values ​​x(k-1), x(k-2), etc., and based on the previous switching decision D(k-1). In the following description, because the value x(k) represents metric P, the value x(k) itself may be referred to as the "metric" or simply "metric x(k)". In the example, the value x(k) may be an 8-bit value converted to a percentage of 0-100%. Lower and higher values ​​indicate better and worse audio quality, respectively. In other words, the degradation in audio quality increases with the value x(k) of metric P. In another example, lower and higher values ​​indicate worse and better audio quality, respectively.

[0044] At point 306a, the algorithm determines / evaluates whether the metric x(k) is above or below the minimum input threshold Th. min (Also known as the "first threshold"), to produce a first value to determine Ymin(k). The algorithm is as follows, recording the results of thresholding test 306a:

[0045] a. Measure x(k) > Th min ?

[0046] → Ymin(k) = 1.

[0047] No → Ymin(k) = 0.

[0048] As used herein, the term "thresholding" refers to comparing a value to a threshold and recording the result; that is, determining whether the value is above or below the threshold and recording the result. For example, the result can be recorded as a binary decision or state. Furthermore, testing whether a value is "above or below" the threshold is more generally referred to as testing whether the value "crosses" the threshold.

[0049] In parallel with 306a, at 306b, the algorithm determines whether the metric x(k) is higher or lower than the maximum input threshold Th that is greater than the first threshold. max (Also known as the "second threshold"), to produce a second value that determines Ymax(k). The algorithm is as follows, recording the results of thresholding test 306b:

[0050] a. Measure x(k) > Th max ?

[0051] → Ymax(k) = 1.

[0052] No → Ymax(k) = 0.

[0053] At 308a, the algorithm calculates the first N sample moving averages Avg_ymin(k) obtained from the current first value determination from the current pass through 306a and the previous Nl first value determinations from the previous N-1 passes through 306a, as follows:

[0054]

[0055] More generally, Avg_ymin(k) (i.e., the Avg above) ymin(k) The average value of N represents the number of times the metric P crosses a first threshold within a given time period (e.g., the Nth interval). This average value represents a measurement or quantification of the fluctuation of the metric P with respect to the first threshold within the given time period, and this can be noticed by the audience.

[0056] In parallel with 308a, at 308b, the algorithm calculates the second N sample moving average Avg_ymax(k) obtained from the current second value decision from the current pass through 306b and the previous Nl second value decisions from the previous N-1 passes through 306b, as follows:

[0057]

[0058] More generally, Avg_ymax(k) (i.e., the Avg above) ymax(k) ) represents the average of the number of times N measures P crossing the second threshold within a given time period (e.g., the Nth interval). This average quantifies the fluctuation of the measure P with respect to the second threshold within a given time period, and is likely to be more apparent to the audience compared to the fluctuation of the measure P with respect to the lower first threshold.

[0059] At 310a, the algorithm determines / evaluates whether the first N-sample moving average Avg_ymin(k) is higher or lower than the minimum average threshold ThAvg2 (also known as the "first average threshold" or "first fluctuation threshold") to produce the first moving average decision Minout(k) (also simply referred to as the "first average decision" and "first fluctuation indicator"). The results of the thresholding test 310a are recorded as follows:

[0060] a. Is the moving average Avg_ymin(k) greater than ThAvg2?

[0061] → Minout(k) = 1.

[0062] No → Minout(k) = 0.

[0063] Minout(k) = 1 indicates that the number and magnitude of fluctuations in the metric P within a given time period are large enough to cause a noticeable and annoying degradation in audio quality to the listener (e.g., first-level degradation); however, this may not be the worst audio degradation.

[0064] At 310b, the algorithm determines / evaluates whether the second N-sample moving average Avg_ymax(k) is higher or lower than the maximum average threshold ThAvg2 (also known as the "second average threshold" or "second fluctuation threshold") to produce a second moving average decision Maxout(k) (also simply referred to as the "second average decision" and "second fluctuation indicator"). In one example, the maximum and minimum average thresholds are equal. In another example, they are different. The algorithm records the results of the thresholding test 310b as follows:

[0065] a.Avg_ymax(k)>ThAvg2?

[0066] Yes → Maxout(k) = 1.

[0067] No → Maxout(k) = 0.

[0068] Maxout(k) = 1 indicates an audio quality degradation (e.g., a second-level degradation greater than the first-level degradation associated with Minout(k) = 1) where the amount and magnitude of fluctuations in metric P over a given time period are large enough to cause noticeable and annoying audio quality degradation to the listener. This indicates the worst audio degradation (relative to Minout(k) = 1).

[0069] At 314, the algorithm derives the switching decision D(k) based on the first average determination / fluctuation indicator Minout(k), the second average determination / fluctuation indicator Maxout(k), and the previous switching decision D(k-1) (collectively referred to as the "state descriptor"). Note that the moving averages Avg_ymin(k) and Avg_ymax(k) represent intermediate fluctuation indicators, while the average determinations Minout(k) and Maxout(k) represent the final fluctuation indicators of the algorithm. The switching decision D(k) is the decision to use either a broadcast radio signal or a wireless network connection as the source of the audio content. In the example described herein, the switching decision D(k) comprises a binary state or value (0,1), where 0 indicates the use of a wireless network signal / wireless network connection, and 1 indicates the use of a broadcast radio signal as the source of the audio content.

[0070] Operation 314 implements the decision matrix for deriving the switching decision D(k). The decision matrix has the following binary inputs and outputs for the switching decision D(k).

[0071] a. Input:

[0072] i. Previous switching decision D(k-1)-(0,1).

[0073] ii. First average value determination / fluctuation indicator Minout(k)-(0,1).

[0074] iii. Second average value determination / fluctuation indicator Maxout(k)-(0,1).

[0075] b. Output: Switching decision D(k) based on state descriptor / input

[0076] (D(k-1):Minout(k):Maxout(k)):

[0077] i. Enter 0:0:1 or 1:0:1

[0078] Illegal state (process restart). Maxout(k) should not be high (indicating high level of audio degradation / poor audio quality) when Minout(k) is low (indicating low level of audio degradation).

[0079] ii. Enter 0:0:0 (low metric – indicates low audio degradation, good audio quality)

[0080] Output D(k) = 1. Switch from wireless network connection to broadcast radio signal.

[0081] iii. Enter 0:1:0 or 0:1:1

[0082] Output D(k) = 0 (no state change). Maintain the wireless network connection as previously decided.

[0083] iv. Enter 1:0:0 or 1:1:0

[0084] Output D(k) = 1 (no state change). The broadcast radio signal continues to be used as per the previous handover decision, since the audio degradation is not too bad. This introduces a hysteresis: even though Minout(k) = 1 indicates that the audio degradation due to fluctuations has exceeded the first level, the handover decision to the broadcast radio signal is maintained at least until Maxout(k) = 0; the handover decision will only switch to the wireless network connection when the audio degradation due to fluctuations also exceeds the second level, i.e., when Minout(k) = 1 and Maxout(k) = 1 (see (v) below).

[0085] v. Input 1:1:1 (height quantity – indicates high-frequency degradation)

[0086] The output is D(k) = 0.

[0087] At 316, the algorithm "time-stretches" or delays the switching decision D(k) to produce a switching signal SW(k) (or "output SW(k)") that follows the switching decision. In other words, operation 316 outputs SW(k) as a delayed version of the switching decision D(k), subject to the conditions presented below. The purpose of time-stretching the switching decision D(k) into SW(k) is to avoid overly aggressive switching between audio sources that could bore the listener. The pulse-stretching feature of operation 316 is optional. For the example described below, the output SW(k) comprises a binary state or value (0,1) similar to the switching decision D(k), where 0 or 1 causes the source selector 206 to select audio content 239 from a wireless network connection or audio content 222 from a broadcast radio signal as output audio content 250, respectively.

[0088] Operation 316 is based on (i) a continuously running hold timer implemented by controller 210 that presents time values ​​to the algorithm at any given time, and (ii) a hold timer logic that resets the timer to derive output SW(k) based on decision logic that evaluates the current switching decision D(k), the previous switching decision D(k-1), the timer value, and the timer thresholds Th(Hold0) and Th(Hold1).

[0089] At 318, the hold timer logic reads the timer value, receives the switching decision D(k):D(k-1), and implements the hold time decision matrix / logic with the following inputs and outputs (output SW(k)) as shown below.

[0090] a. Input:

[0091] i. Previous switching decision D(k-1).

[0092] ii. Current switching decision D(k).

[0093] iii. Timer value.

[0094] b. Output SW(k) based on input D(k-1):D(k) and timer value:

[0095] i. 0:0 or 1:1 - D(k-1) and D(k) remain unchanged because D(k) follows

[0096] D(k-1)

[0097] SW(k) = D(k), no change, no timer reset (322).

[0098] ii.1:0 - Switching timer value for connection from wireless network to broadcast radio signal > Th(Hold1)? (324)

[0099] → SW(k) = 0, reset timer (326).

[0100] No → SW(k) = D(k), no change, no timer reset (328).

[0101] iii. 0:1 - Timer value > Th(Hold0)? (330)

[0102] → SW(k) = 1, reset timer (332).

[0103] No → SW(k) = D(k), no change, no timer reset (334).

[0104] In an embodiment, the algorithm can qualify a switching decision that leads to a shift from using broadcast radio signals to using a wireless network connection as the source of audio content (e.g., see the switching decision described in paragraph 45(b)(v) above). The algorithm can qualify such a switching decision based on a wireless network connection quality indicator provided by network radio device 204, as described above in conjunction with... Figure 2The algorithm, for example, first determines whether the wireless network connection quality indicator indicates a good or poor connection whenever a handover decision would result in a switch from using a broadcast radio signal as the source of audio content. When the wireless network connection is good, the algorithm allows the handover / transition. When the wireless network connection is poor, the algorithm does not allow the handover, i.e., it overturns the handover decision. In the latter case, the algorithm maintains the connection with the broadcast radio signal as the source of audio content. In summary, the algorithm determines whether to overturn a handover decision that would result in a switch from using a broadcast radio signal as the source of audio content to using a wireless network connection as the source of audio content based on the wireless network connection quality indicator: poor quality - overturn, good quality - do not overturn.

[0105] As mentioned above, the values ​​of various parameters / variables in the switching algorithm affect the outcome of the operation performed by the switching algorithm. These parameters include, for example, the time interval for collecting values ​​of the metric P, the number of decisions N for which averaging is required, and the first, second, and third thresholds Th, respectively. min ,Th max And ThAvg2, as well as timer thresholds Th(Hold0) and Th(Hold1). The values ​​of these parameters drive the aggressiveness, that is, the switching algorithm determines the frequency of switching between broadcast radio signals and wireless network connections. For example, the threshold Th min and Th max The lower and higher values ​​tend to increase or decrease the aggressiveness of the switching between sources, i.e., the frequency at which the switching algorithm decides to switch between using broadcast radio signals and deciding to use wireless network radio.

[0106] In addition to driving the aggressiveness of the handover decision, the parameter value can be configured to bias the handover decision relative to the wireless network connection toward the broadcast radio signal based on the previous source decision and fluctuation indicator (i.e., having a value set to bias the handover decision relative to the wireless network connection toward the broadcast radio signal). Alternatively, the parameter value can be configured to bias the handover decision relative to the broadcast radio signal toward the wireless network connection based on the previous source decision and fluctuation indicator.

[0107] In this embodiment, the values ​​of the parameters / variables are configurable / programmable. Initial values ​​can be programmed during prior configuration / provisioning operations performed on the hybrid radio receiver. Subsequently, the radio broadcaster can dynamically update / program the parameter values ​​over time to achieve desired audio performance and switching aggression, and to implement desired switching decisions biased towards the broadcast radio signal or the wireless network connection. To dynamically update the parameters, the radio broadcaster can be configured to transmit parameter update commands / messages as data packets to the hybrid radio receiver via the wireless network connection. The parameter update command may include (i) the IP address of the network radio device (i.e., matching the IP address assigned to the network radio device), (ii) a message type identifier (MTI) to identify the message as a parameter update message for the switching algorithm, (iii) an identifier of the switching algorithm parameter to be updated, and (iv) the updated value of the identified parameter. Example parameter update commands are shown in Table 2 below.

[0108] Network radio IP address Message / command type = parameter update Parameter 1 : update value Parameter 2: update value Parameter 4: update value

[0109] Table 2

[0110] Upon receiving a data packet including a parameter update command (identified by the network radio device based on packet parsing to retrieve and identify the IP address and message / command type), the network radio device retrieves the updated value for the identified parameter from the parameter update command and updates the identified parameter in the handover algorithm with its corresponding updated value. In summary, the handover algorithm includes performing the following operations: parameters with values ​​that are programmable and influence the handover algorithm, determining the frequency at which the handover is performed between the broadcast radio signal and the wireless network connection, and a source selection bias derived fluctuation indicator associated with the handover decision. Dynamic parameter updates may include receiving the updated value of the parameter via the wireless network connection in the parameter update command and updating the parameter with the updated value from the parameter update command to adjust the frequency (i.e., aggressiveness) at which the handover decision performs the handover between the broadcast radio signal and the wireless network connection, and / or adjust the bias of the handover decision. The parameter update technique mentioned above has the advantage that the same parameter value affects all hybrid radio receivers, which are equally fielded in terms of perceived audio quality, regardless of their antenna system / radio quality. Therefore, parameter update technology allows broadcasters to provide a certain level of quality over time, which may benefit wireless network connections or broadcast radio signals as the business environment changes (e.g., streaming usage fees decrease).

[0111] Figure 4This is a flowchart of an example method 400 (i.e., a method executed by a switching algorithm) that derives a switching decision based on metric P. Method 400 may be executed primarily by a controller (e.g., controller 210) in a hybrid radio receiver (e.g., hybrid radio receiver 110), which is configured to recover audio content separately from broadcast radio signals and wireless network connections.

[0112] At 402, at periodic intervals, the controller collects values ​​(e.g., x(k)) of a metric (e.g., metric P) indicating the audio quality of the audio content in the broadcast radio signal. At each interval (e.g., for each k), the controller performs operations 404-410 as described below.

[0113] At 404, the controller calculates how many of the N values ​​of the metric (including the current value and N-1 previous values) exceed / cross a first threshold (e.g., Th). min The first average value (e.g., the first moving average Avg_min(k)) is calculated, and the number of N values ​​that exceed a second threshold (e.g., Th) is calculated. max The second average (e.g., Avg_max(k)). In the example, the first average is averaged over the first values ​​determined by thresholding each value against a first threshold (e.g., Ymin(k)), and the second average is averaged over the second values ​​determined by thresholding each value against a second threshold (e.g., Ymax(k)).

[0114] At 406, the controller obtains a first average determination / fluctuation indicator (e.g., Minout(k)) and a second average determination / fluctuation indicator (Maxout(k)) to indicate whether the first average and the second average exceed a third threshold (e.g., ThAvg2), respectively.

[0115] At 408, the controller derives a source decision (e.g., D(k)) for the audio content source, using either a broadcast radio signal or a wireless network connection, based on a previous source decision (e.g., D(k-1)), a first average decision / fluctuation indicator (e.g., Minout(k)), and a second average decision / fluctuation indicator (Maxout(k)). The previous source decision, the first average decision, and the second average decision may each comprise a binary decision and together represent a state descriptor evaluated for each interval. The controller derives a handover decision based on the state descriptor, such that the handover decision is biased towards the broadcast radio signal relative to the wireless network connection or vice versa, and incorporates hysteresis into the handover decision.

[0116] At 410, the controller selects or broadcasts a radio signal or wireless network connection as the source of audio content based on a switching decision (e.g., SW(k) after D(k)).

[0117] Figure 5 This is a flowchart of another example method 500 for deriving switching decisions based on metric P. Method 500 can be primarily executed by a controller in a hybrid radio receiver configured to recover audio content separately from broadcast radio signals and from a wireless network connection.

[0118] At 502, the controller receives a value (e.g., x(k)) of a metric (e.g., metric P) that indicates the audio quality of the audio content in the broadcast radio signal at any given time.

[0119] At 504, the controller calculates / derives a fluctuation indicator (i.e., a fluctuation indicator) based on the fluctuation of the metric value over time, representing audio quality fluctuations that the listener might notice. Controller 504 can use the above combination... Figure 3 and 4 The operations described are used to compute fluctuation indicators (e.g., represented by Avg_ymin(k), Minout(k), Avg_ymax(k), and Maxout(k)).

[0120] For example, the controller determines whether a metric's value crosses a first threshold over a period of time (e.g., Th). min The first fluctuation indicator (e.g., Avg_ymin(k), Minout(k)) is calculated as a function of the number of times the metric crosses the second threshold (e.g., Th) within that time period. max The second fluctuation indicator is calculated as a function of the number of times the value crosses a first threshold (e.g., Avg_ymax(k), Maxout(k)). Furthermore, the first fluctuation indicator can be based on a first average of the first number of times the value crosses a first threshold, and the second fluctuation indicator can be based on a second average of the second number of times the value crosses a second threshold.

[0121] At point 506, the controller derives a switching decision (e.g., D(k-1)) based on previous switching decisions (e.g., D(k-1)) and fluctuation indicators (e.g., first fluctuation indicator Minout(k), second fluctuation indicator Maxout(k)) to use broadcast radio signals or wireless network connections as the source of audio content, incorporating hysteresis into the switching decision and favoring broadcast radio signals (or alternatively, wireless network connections). The controller derives the switching decision according to the following decision matrix:

[0122] a. (0:0:0, Operation 314(ii) above) When the previous handover decision is to use a wireless network connection and neither the first fluctuation indicator nor the second fluctuation indicator exceeds the fluctuation threshold (e.g., ThAvg2), set the handover decision to use a broadcast radio signal (e.g., D(k) = l).

[0123] b. (0:1:0 or 0:1:1, operation 314(iii) above) When the previous handover decision is to use a wireless network connection and at least the first fluctuation indicator exceeds the fluctuation threshold, the handover decision follows the previous handover decision.

[0124] c. (1:0:0 or 1:1:0, operation 314(iv) above) When the previous handover decision was to use a broadcast radio signal, the first fluctuation indicator, or when the fluctuation threshold was exceeded or not exceeded and the second fluctuation indicator did not exceed the fluctuation threshold, the handover decision follows the previous handover decision. This introduces hysteresis because even when the first handover decision exceeds the fluctuation threshold, the handover decision maintains its current setting until the second fluctuation decision also exceeds the fluctuation threshold; at this point, the handover decision reverts to a wireless network connection (see (d) below).

[0125] d. (1:1:1, Operation 314(v) above) When the previous switching decision is to use the broadcast radio signal and both the first fluctuation indicator and the second fluctuation indicator exceed the fluctuation threshold, set the switching decision to use the wireless network connection.

[0126] At 508, the controller selects either a broadcast radio signal or a wireless network connection as the source of audio content based on a switching decision.

[0127] In other embodiments, the hybrid radio receiver 110 may further include a radio receiver configured to process digitally modulated radio signals, such as HD radio signals, to recover audio content from the digitally modulated radio signals separately from the network radio device 204 and to provide the audio content to the source selector 206. The radio receiver may replace or be added to the radio broadcast receiver 202. The radio receiver may monitor the quality of the digitally modulated radio signals and provide the controller 210 with an indicator or metric (similar to metric P) indicating this quality. The controller 210 may implement a switching algorithm similar to the algorithm described above to provide switching decisions for using either the digitally modulated radio signals or the wireless network signals as the source of the audio content.

[0128] In summary, in one embodiment, a method is provided comprising: at a hybrid radio receiver configured to separately recover audio content from a broadcast radio signal and from a wireless network connection: receiving a reception metric indicating the audio quality of the audio content in the broadcast radio signal at any given time; deriving a fluctuation indicator indicating fluctuations in audio quality that a listener may notice based on fluctuations in the reception metric over time; deriving a switching decision to use either the broadcast radio signal or the wireless network connection as the source of the audio content based on a previous switching decision and the fluctuation indicator; and selecting either the broadcast radio signal or the wireless network connection as the source of the audio content based on the switching decision.

[0129] In another embodiment, a hybrid radio receiver-type apparatus is provided, comprising: a radio broadcast receiver for recovering audio content from a broadcast radio signal and deriving a metric indicating the audio quality of the audio content at any given time; a network radio device for recovering audio content from a wireless network connection; and a controller that performs the following operations: deriving a fluctuation indicator indicating audio quality that a listener may notice by: (i) deriving a first fluctuation indicator based on the number of times a first threshold is crossed over a period of time, and (ii) deriving a second fluctuation indicator based on the number of times a second threshold greater than the first threshold is crossed during the period of time; and deriving a switching decision to use either the broadcast radio signal or the wireless network connection as the source of the audio content based on a previous switching decision, the first fluctuation indicator, and the second fluctuation indicator, to incorporate hysteresis into the switching decision.

[0130] In yet another embodiment, a non-transitory computer-readable medium is provided. The medium is encoded with instructions that, when executed by a processor of a hybrid radio receiver configured to separately recover audio content from broadcast radio signals and from wireless network connections, cause the processor to: periodically collect values ​​of metrics indicative of the audio quality of audio content in the broadcast radio signals, and in each interval perform: calculating how many of N values ​​of the metrics exceed a first average value of a first threshold, and calculating how many of the N values ​​exceed a second average value of a second threshold greater than the first threshold; obtaining a first average value decision and a second average value decision respectively indicating whether the first average value and the second average value exceed a third threshold; and, based on a previous source decision, the first average value decision, and the second average value decision, derive a switching decision to use either the broadcast radio signals or the wireless network connection as the source of the audio content; and select a source of the audio content based on the switching decision.

[0131] Although the techniques described herein are illustrated and depicted as implemented in one or more specific examples, they are not intended to be limited to the details shown, as various modifications and structural changes may be made within the scope and limits of the equivalents of the claims.

[0132] Each claim presented below represents a separate embodiment, and embodiments combining different claims and / or different embodiments will be apparent to those skilled in the art upon reading this disclosure.

Claims

1. A hybrid radio receiving method, comprising: At a hybrid radio receiver configured to recover audio content separately from broadcast radio signals and from wireless network connections: The received measure is the audio quality of the audio content in a broadcast radio signal at any given time. A fluctuation indicator is derived based on the fluctuation of received measurements over time to indicate the audio quality fluctuations that listeners may notice. Based on previous switching decisions and fluctuation indicators, a switching decision is derived that uses broadcast radio signals or wireless network connections as the source of audio content. as well as The decision to switch between broadcast radio signals and wireless network connections is based on the choice of audio content source. The derived fluctuation indicator includes: A first fluctuation indicator is calculated based on the first number of times the reception metric crosses a first threshold within a certain period of time; and A second fluctuation indicator is calculated based on the second number of times the received measurement crosses a second threshold greater than the first threshold within that time period; and The switching decision is derived based on a first volatility indicator, a second volatility indicator, and a previous switching decision; and Calculating the first fluctuation indicator includes calculating a first average value of the first number of times the reception metric crosses the first threshold; and The calculation of the second fluctuation indicator includes calculating a second average of the second number of times the reception metric crosses the second threshold.

2. The hybrid radio reception method of claim 1, wherein the derivation includes deriving the handover decision based on previous handover decisions and fluctuation indicators to incorporate hysteresis into the handover decision.

3. The hybrid radio reception method as described in claim 1, wherein deriving the handover decision includes: When the previous handover decision was to use a wireless network connection and neither the first fluctuation indicator nor the second fluctuation indicator exceeded the fluctuation threshold, a handover decision to use broadcast radio signals was derived.

4. The hybrid radio reception method of claim 3, wherein deriving the handover decision includes: When the previous handover decision was to use broadcast radio signals and both the first and second fluctuation indicators exceeded the fluctuation threshold, a handover decision to use a wireless network connection was derived.

5. The hybrid radio reception method of claim 1, wherein deriving the handover decision includes: If the previous handover decision was to use broadcast radio signals, the first fluctuation indicator, or if the second fluctuation indicator exceeds or does not exceed the fluctuation threshold, the previous handover decision shall be followed.

6. The hybrid radio reception method of claim 5, wherein deriving the handover decision includes: If the previous handover decision was to use a wireless network connection and at least one of the first and second fluctuation indicators exceeds a threshold, the previous handover decision shall be followed.

7. The hybrid radio receiving method of claim 1, wherein the audio content includes audio and metadata.

8. The hybrid radio receiving method of claim 1, wherein deriving the handover decision includes deriving the handover decision without using the Received Signal Strength Indicator (RSSI) value used for broadcasting radio signals.

9. The hybrid radio receiving method of claim 1, wherein the receiving metric is derived from audio content recovered from a broadcast radio signal.

10. The hybrid radio receiving method of claim 1, wherein the broadcast radio signal includes an FM broadcast signal.

11. The hybrid radio receiving method of claim 1, wherein the wireless network connection includes a cellular or WiFi connection.

12. The hybrid radio reception method of claim 1, wherein the derived fluctuation indicator comprises a parameter-derived fluctuation indicator having a programmable value that influences the frequency at which a handover decision is made to perform a handover between a broadcast radio signal and a wireless network connection, and the hybrid radio reception method further comprises: The system receives updated parameter values ​​via a wireless network connection and updates the parameters with these updated values ​​to adjust the frequency at which the handover decision is made to switch between broadcast radio signals and the wireless network connection.

13. A hybrid radio receiver, comprising: A radio receiver for recovering audio content from broadcast radio signals and deriving a metric indicating the audio quality of the audio content at any given time; A network radio device used to recover audio content from a wireless network connection; as well as The controller is used to perform: The following operations are used to derive an indicator of audio quality fluctuations that may be noticed by the listener: (i) derive a first fluctuation indicator based on the number of times a first threshold is crossed over a period of time, and (ii) derive a second fluctuation indicator based on the number of times a second threshold greater than the first threshold is crossed over that period of time. as well as Based on the previous switching decision, the first fluctuation indicator and the second fluctuation indicator, a switching decision is derived that uses broadcast radio signals or wireless network connections as the source of audio content, so as to incorporate hysteresis into the switching decision. The controller is configured to derive a first fluctuation indicator by calculating a first average of the number of times a first threshold is crossed; Furthermore, the controller is configured to derive a second fluctuation indicator by calculating a second average of the number of times a metric crosses a second threshold.

14. The hybrid radio receiver of claim 13, wherein the controller is further configured to perform: The source of the audio content is selected based on the switching decision.

15. The hybrid radio receiver of claim 13, wherein: The controller is also configured to perform a first fluctuation indicator by thresholding a first average value against an average value threshold. as well as The controller is also configured to perform a second fluctuation indicator by thresholding a second average value against an average value threshold.

16. The hybrid radio receiver of claim 13, wherein the controller is configured to perform a switching decision without using the Received Signal Strength Indicator (RSSI) value used for broadcasting radio signals.

17. A non-transitory computer-readable medium encoded with instructions that, when executed by a processor of a hybrid radio receiver configured to separately recover audio content from broadcast radio signals and from wireless network connections, cause the processor to perform: Values ​​of metrics indicating the audio quality of audio content in broadcast radio signals are collected at periodic intervals, and the following is performed at each interval: Calculate how many of the N values ​​of the metric exceed the first average value of the first threshold, and calculate how many of the N values ​​exceed the second average value of the second threshold, which is greater than the first threshold; Obtain a first average decision and a second average decision that respectively indicate whether the first average and the second average exceed a third threshold; and Based on the previous source decision, first average decision, and second average decision, a switching decision is derived for using or broadcasting radio signals or wireless network connections as the source of audio content; as well as The source of the audio content is selected based on the switching decision.

18. The non-transitory computer-readable medium of claim 17, further comprising instructions that cause the processor to perform the following operations during each said interval: Obtaining a current first value decision indicating whether the current value of the indicator metric exceeds a first threshold, wherein calculating the first average includes calculating the first average as a first moving average of the current first value decision and previous first value decisions; and Obtain a current second value decision indicating whether the current value exceeds a second threshold, wherein calculating the second average includes calculating the second average as a moving average of the current second value decision and the previous second value decision.

19. The non-transitory computer-readable medium of claim 17, wherein the derivation is based on a prior source determination, a first average determination, and a second average determination, relative to the wireless network connection biased towards the broadcast radio signal.

20. The non-transitory computer-readable medium of claim 17, wherein the prior source determination, the first average determination, and the second average determination are derived relative to the broadcast radio signal biased towards the wireless network connection.

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