Methods and apparatuses for efficient battery utilization during content delivery in telecommunication networks

Abstract

Apparatuses and methods for controlling a manner of delivering content to a content user in a mobile telecommunication network are provided. The content is sent to the content user using first a first transmission rate when the content user is in a first radio state and uses a first battery power, and then using a second transmission rate that is lower than the first transmission rate, when the content user is in a second radio state and uses a second battery power that is smaller than the first battery power. The sending is performed such as, (A) while delivering the content, an amount of the content already received by the content user to exceed an amount of the content used by the content user, and (B) to minimize an energy used by the content user during delivery.

Claims

1. A method for controlling delivery of multimedia content from a content source provider to a user equipment (UE), the method comprising: sending, by the apparatus configured to control the delivery of multimedia content, the multimedia content at a first transmission rate during a first time interval, and then at a second transmission rate during a second time interval, wherein the second transmission rate is lower than the first transmission rate, and wherein the first time interval is based on a size of the multimedia content; and storing, by the UE, the received multimedia content in a buffer.

2. The method of claim 1, further comprising: sending, by the apparatus configured to control delivery of multimedia content, respective state configuring signals before starting to send the multimedia content at the first transmission rate or at the second transmission rate.

3. The method of claim 1, wherein the UE uses less power for receiving the multimedia content at the second transmission rate than at the first transmission rate.

4. The method of claim 1, wherein the first time interval is also based on the first transmission rate and a playout rate of the multimedia content at the UE.

5. The method of claim 1, wherein the multimedia content is sent from a proxy via a base station, an eNodeB, or a WiFi access point.

6. The method of claim 1, wherein the first transmission rate is larger than a playout rate of the multimedia content at the UE.

7. The method of claim 1, further comprising: sending, by the apparatus configured to control delivery of multimedia content, a remaining portion of the multimedia content using the second transmission rate if a playout rate is smaller than a value of a delivery rate measured by the apparatus during the second time interval, at which delivery rate the apparatus sends the multimedia content.

8. The method of claim 1, further comprising: sending, by the apparatus configured to control delivery of multimedia content, a remaining portion of the multimedia content using the second transmission rate if an estimated delivery time that is necessary for the apparatus to send the remaining portion of the multimedia content at a delivery rate measured by the apparatus during the second time interval, at which delivery rate the apparatus sends the multimedia content, is less than a remaining time for the UE to complete playing out the multimedia content.

9. The method of claim 1, further comprising: sending, by the apparatus configured to control delivery of multimedia content, the multimedia content at the first transmission rate during a third time interval subsequent to sending the multimedia content at the second transmission rate during the second time interval.

10. The method of claim 1, further comprising: sending, by the apparatus configured to control delivery of multimedia content, the multimedia content at different transmission rates during respective time intervals to avoid under-run of the buffer and to minimize a time during which the multimedia content is sent at the first transmission rate.

11. A system for controlling delivery of multimedia content from a content source provider to a user equipment (UE), the system comprising: an apparatus configured to send multimedia content, the apparatus comprising: a processor configured to send the multimedia content at a first transmission rate during a first time interval, and then at a second transmission rate during a second time interval, wherein the second transmission rate is lower than the first transmission rate, wherein the first time interval is based on a size of the multimedia content; and the user equipment (UE) configured to receive multimedia content, the user equipment comprising: a processor and a memory configured to store the received multimedia content in a buffer.

12. The system of claim 11, wherein the processor of the apparatus is further configured to: send respective state configuring signals before starting to send the multimedia content at the first transmission rate or at the second transmission rate.

13. The system of claim 11, wherein the UE uses less power for receiving the multimedia content at the second transmission rate than at the first transmission rate.

14. The system of claim 11, wherein the first time interval is also based on the first transmission rate and a playout rate of the multimedia content at the UE.

15. The system of claim 11, wherein the multimedia content is sent from a proxy via a base station, an eNodeB, or a WiFi access point.

16. The system of claim 11, wherein the first transmission rate is larger than a playout rate of the multimedia content at the UE.

17. The system of claim 11, wherein the processor of the apparatus is further configured to: send a remaining portion of the multimedia content using the second transmission rate if a playout rate is smaller than a value of a delivery rate measured by the apparatus during the second time interval, at which delivery rate the apparatus sends the multimedia content.

18. The system of claim 11, wherein the processor of the apparatus is further configured to: send a remaining portion of the multimedia content using the second transmission rate if an estimated delivery time that is necessary for the apparatus to send the remaining portion of the multimedia content at a delivery rate measured by the apparatus during the second time interval, at which delivery rate the apparatus sends the multimedia content, is less than a remaining time for the UE to complete playing out the multimedia content.

19. The system of claim 11, wherein the processor of the apparatus is further configured to: send the multimedia content at the first transmission rate during a third time interval subsequent to sending the multimedia content at the second transmission rate during the second time interval.

20. The system of claim 11, wherein the processor of the apparatus is further configured to: send the multimedia content at different transmission rates during respective time intervals to avoid under-run of the buffer and to minimize a time during which the multimedia content is sent at the first transmission rate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:

(2) FIG. 1 is a schematic diagram of a conventional content delivery system;

(3) FIG. 2 is a graph-flow of states and transitions;

(4) FIG. 3 is a graph illustrating abandonment rate relative to viewing time;

(5) FIG. 4 is a graph illustrating a delivery of the whole content using only the highest data rate;

(6) FIG. 5 is a graph illustrating a delivery of the content using different data rates, according to one exemplary embodiment;

(7) FIG. 6 is a graph illustrating another delivery of the content using different data rates, according to another exemplary embodiment;

(8) FIG. 7 is a graph illustrating other manners of delivering the content using different data rates, according to other exemplary embodiments;

(9) FIG. 8 is a flow diagram illustrating operations taking place while delivering a video file using a strategy according to an exemplary embodiment;

(10) FIG. 9 is a flow diagram illustrating a method according to an exemplary embodiment;

(11) FIG. 10 is a schematic diagram of an apparatus according to an exemplary embodiment; and

(12) FIG. 11 is a flow diagram of a method according to an exemplary embodiment.

DETAILED DESCRIPTION

(13) The following description of the exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to the terminology and structure of a content delivery system in a mobile network, for example, a system meeting the characteristics described in the current 3GPP documentation. However, the embodiments to be discussed next are not limited to these systems but may be applied to other existing content delivery systems, such as (but not limited to) WIFI systems.

(14) Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily all referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

(15) Studies have also shown that often a user abandons data transfer after using a relative small portion from the entire content. For example, when video is streamed (e.g., from a service such as YouTube), users often view just the first part of a video and skip the rest due to absence of interest in the content. FIG. 3 is a graph illustrating the correlation between the abandonment rate (on y-axis) and the viewed time (on x-axis). Thus, the longer the average viewer watches a clip, the more likely he or she is to abandon it. The benchmark initial abandonment rate of 19.4% is nearly double previously reported industry figures. Further, the rate of viewer abandonment increases along a relatively predictable trajectory: 33.4% abandonment at 30 seconds of playback; 44.1% abandonment at 60 seconds; 52.5% at 90 seconds; and 58.5% at 120 seconds.

(16) Various embodiments of the inventive concept provide apparatuses and methods of finding a battery efficient mode of delivery a video stream, which takes into account the viewer abandonment factor. The embodiments may include using a proxy located between content source provider (i.e., the origin server), and the fixed or mobile user terminal (i.e., UE). The apparatus receives multimedia content from the content source provider, and determines a sequence of states to be used to send the video file to the terminal. Each state lasts a specific time interval during which the transfer is delivered using a certain transfer rate. In other words, the selection of a state also means the selection of a transfer rate. The content has to be delivered to the terminal (UE) such that to avoid a buffer under-run situation, in which a shortage of video data to be played-out occurs and the video play-out stops (i.e. a blank screen). Meanwhile the energy used for the delivery is sought to be minimized. To generalize without limiting, one may assume that the content is transferred using at least a first transmission rate when the content user is in a first radio state, and a second transmission rate that is lower than the first transmission rate, when the content user is in a second radio state. The content user uses more battery power while in the first radio state than when it is in the second radio state.

(17) One simplistic strategy (illustrated in FIG. 4) is to send all the data using the first transmission rate. In FIG. 4, the y axis represents transmission rates and the x axis represents time. This simplistic strategy is represented as the line 410 where the transmission rate TR.sub.DCH is constant for t.sub.DCH. Parallel with the content delivery, the content is played-out at TR.sub.clip for t.sub.clip time. The graph area A.sub.0=TR.sub.clip×t.sub.clip is substantial equal with the graph area A.sub.1=TR.sub.DCH×t.sub.DCH being an illustration of the size of the content (e.g., video clip). However, this “high-rate only” simplistic approach is not optimal, but it may be employed when the size of the clip is small.

(18) A preferred strategy which is illustrated in FIG. 5, is to transmit first a burst of content (e.g., video data) in high radio state (DCH) at the beginning of the delivery, and, then to continue sending video data in a low radio state (FACH). In other words as represented by the line 510, the first transmission rate TR.sub.DCH is constant for t.sub.DCH′ and then, the second transmission rate TR.sub.FACH is constant until t.sub.FACH. The effect of this strategy is that the delivery is paced out over time, and, if the viewer abandons using the content (i.e., watching the video clip), an amount as little as possible of video data is wasted (having already been delivered). The graph area A.sub.0=TR.sub.clip×t.sub.clip is substantial equal with the graph area A.sub.2=TR.sub.DCH×t.sub.DCH+TR.sub.FACH×(t.sub.FACH−t.sub.DCH) being an illustration of the size of the content (e.g., video clip).

(19) In FIG. 5, the second transmission rate TR.sub.FACH is larger than the rate of using the content (i.e., at which the content is played-out) TR.sub.clip. However, as illustrated in FIG. 6, the second transmission rate TR.sub.FACH may be smaller than the rate of using the content (i.e., at which the content is played-out) TR.sub.clip. Depending on relative sizes of t.sub.DCH, t.sub.FACH, and t.sub.clip it is possible that the delivered content be exhausted and then the playout may be impeded by lack of content to be played as illustrated in FIG. 6.

(20) In order to avoid the playout being impeded by lack of content to be played, as illustrated in FIG. 7 another period of using the first (high) transmission rate may be employed. This additional period of using the first (high) transmission rate may last until the whole content is delivered as represented by 710, or only as long as to buffer enough delivered content to ensure that an amount of the content already received by the content user exceeds an amount of the content used by the content user, while delivering the content, as represented by 720. The manner of delivering the content, i.e., duration and sequence of using different transmission rates is such as, besides ensuring enough content to be played out, to minimize a time during which the content user is in the first radio state, wherein the content user uses a first battery power larger than a second battery power while in the second radio state.

(21) The transition between states is also associated with a certain amount of signaling. The time and energy consumed during transition have also to be taken into consideration. The apparatus (or, more specific, a processing unit of the apparatus) is configured to send respective state configuring signals to the content user before starting to send the content using the first transmission rate or using the second transmission rate.

(22) The optimization may include finding duration t.sub.DCH′ of the transfer at high rate (in DCH state) at the beginning of the video content delivery, and implicitly the duration of the transfer at the low rate until the end of the video file delivery t.sub.FACH. The energy consumed Q for transferring the video file to the terminal (UE) is power multiplied with time, and, thus, it is proportional to the current I multiplied with time t (the potential difference V being constant): Q=IVt. Some constraints have to be met: the data (transfer or played-out) rate multiplied with time for A2, A1, and A0 are equal. The minimum time at which video data is transferred at high rate may be required to be larger than a predetermined value, e.g., 10 s. The goal of the optimization is to use less battery energy when employing a strategy such as A2 than when, such as A1, only high delivery rate is used: Q.sub.A2<Q.sub.A1.

(23) For example, FIG. 8 is a flow diagram illustrating operations taking place while delivering a video file using a strategy according to an exemplary embodiment, in a system 800. The apparatus 810 controls delivery of content towards the user equipment (UE) 830 via a base-station (NB) 820, eNodeB or WiFi access point. The apparatus 810 may be associated with a cache memory 840 where the content received from the content source is stored. The apparatus 810 learns or measures duration of the content (e.g., video clip) and playout rate at S811. The apparatus 810 also includes a timer (i.e., some time measuring means) that assists in measuring predetermined periods of time, such as t.sub.DCH during which the content is transferred using the first (high) transmission rate. At S812, the timer starts measuring t.sub.DCH, and may provide a signal when t.sub.DCH expires.

(24) The apparatus 810 sends a message “1” to NB 820 to signal the UE 830 to switch to the DCH state. NB 820 sends a reconfiguration message “2” accordingly. The UE 830 transitions to the DCH state and sends a message “3” to NB 820 regarding to this transition. NB 820 further informs the apparatus 810 about the transition via a message “4.” Upon receiving the message “4,” the apparatus 810 streams content towards UE 830 via NB 820 using the first (DCH) transmission rate as illustrated by “5.” The apparatus 810 then measures (occasionally or monitors) an actual transfer rate TR.sub.DCH at S813.

(25) After t.sub.DCH expires at S814, the apparatus 810 sends a message “6” to NB 820, to signal the UE 830 to switch to the FACH state. NB 820 sends a reconfiguration message “7” accordingly. The UE 830 transitions to the FACH state at S832, and sends a message “8” to NB 820 regarding to this transition. NB 820 further informs the apparatus 810 about the transition via a message “9.”

(26) The apparatus 810 then measures an actual transfer rate TR.sub.FACH at S815. The measured TR.sub.FACH is compared with the play-out rate at S816. If TR.sub.FACH is larger than the play-out rate (i.e., the “+” branch), the rest of the content is delivered while the UE remains in the FACH state. If TR.sub.FACH is smaller than the play-out rate (i.e., the “−” branch), at S818, the apparatus 810 uses an algorithm in which the used energy is evaluated to determine a manner of transmitting the rest of the content. The apparatus 810 also sends to sends a message “10” to NB 820, to signal the UE 830 to switch to the DCH state. NB 820 sends a reconfiguration message “11” accordingly. The rest of the message is then streamed as indicated by “12.”

(27) FIG. 9 is a flow diagram illustrating a method 900 which is an exemplary embodiment of the algorithm that evaluates the used energy to determine a manner of transmitting the rest of the content (e.g., a clip) at S818. The method first determines the size of the clip, at S910, and the size of the clip left to be streamed (i.e., the rest of the content), at S920. Then, a time necessary to deliver the clip left to be streamed is calculated at S930. At S940, the calculated time is compared with a remaining time to the end of the clip. If the calculated time is equal to or less than the remaining time (i.e., the “+” branch), the rest of the clip is delivered using the DCH state, at S950.

(28) The calculated time is compared with a remaining time to the end of the clip. If the calculated time is larger than the remaining time (i.e., the “−” branch), a first energy Q.sub.DCH is used if the clip left to be streamed (i.e., the rest of the content) is streamed while the UE is in the DCH state is calculated at S960, and a second energy Q.sub.mix used if the clip left to be streamed (i.e., the rest of the content) is streamed while the UE is both in the DCH state and in the FACH state is calculated at S970.

(29) The first energy Q.sub.DCH and the second energy Q.sub.mix are compared at S980. If first energy Q.sub.DCH is larger than the second energy Q.sub.mix (i.e., the “+” branch), at S990, the UE is reconfigured to the FACH state where it uses the lower power level. Otherwise (i.e., the “−” branch), the UE is maintained in the DCH state, S950.

(30) According to another exemplary embodiment, an apparatus 1000 capable to determine a manner in which multimedia content is delivered from a source proxy to a UE in a mobile network, while taking into consideration the user drop-out rate, and using the UE battery efficiently, may include an input/output interface 1010 and a processor 1020, as illustrated in FIG. 10. The controller 1000 may further include a computer readable storage medium 1030 storing software (i.e., executable codes) which, when executed by the processor 1020, determines the processor 1020 to optimize a manner in which multimedia content is delivered from a source proxy to a UE in a mobile network, while taking into consideration the user drop-out rate and using the UE battery efficiently.

(31) A flow diagram of a method 1100 employed in controlling a content delivery from a source proxy towards a UE in a mobile network, according to an exemplary embodiment, is illustrated in FIG. 11. The method 1100 includes receiving the content from the content source provider, at S1110, and sending the content to the content user using first a first transmission rate when the content user is in a first radio state, and then a second transmission rate that is lower than the first transmission rate, when the content user is in a second radio state. The content user uses a first battery power while in the first radio state, and a second battery power while in the second radio state, the second battery power being smaller than the first battery power. The sending is performed such that, (A) while delivering the content, an amount of the content already received by the content user to exceed an amount of the content used by the content user, and (B) to minimize a time during which the content user is in the first radio state.

(32) In one embodiment, the method 1100 may further include sending respective state configuring signals to the content user before starting to send the content using the first transmission rate or using the second transmission rate. In the same or another embodiment, the proxy may communicate with the content user via a base station (NB), which is an eNodeB or a WiFi access point.

(33) In one embodiment, the method 1100 may also include storing the content received from the content provider to be sent to the content user. The method 1100 may also include determining a first time interval for sending the content using the first transmission rate, based on a size of the content, a playout rate, the first transmission rate and the second transmission rate, the first transmission rate being larger than the playout rate.

(34) In another embodiment, the method 1100 may further include receiving measurements of a delivery rate at which the content user receives the content, and sending a remaining portion of the content using the second transmission rate if the playout rate is smaller than a value of the delivery rate measured while the content user is in the second radio state after the first time interval. Besides these operations, the method may additionally include sending the remaining portion of the content using the second transmission rate if an estimated delivery time that is necessary for the content user to receive a remaining portion of the content according to the value of the delivery rate measured while the content user is in the second radio state, is less than a remaining time for the content user to entirely use the content. Further, in combination with these operations, the method may also include, if the estimated delivery time exceeds the remaining time for the content user to entirely use the content, calculating a first amount of energy used by the content user to receive the remaining portion of the content while in the first state, and a second amount of energy used by the content user to receive the remaining portion of the content while in the first state and in the second state, using a first battery power corresponding to the first radio state and a second battery power corresponding to the second radio state. The method 1100 would then also include sending the remaining portion of the content using the first transmission rate if the first amount of energy exceeds the second amount of energy, or sending the remaining content using the first transmission rate and the second transmission rate if the first amount of energy does not exceed the second amount of energy. In one embodiment, the method may also include estimating the remaining portion of the content using at least one value of the delivery rate measured while the content user is in the first radio state, during the first time interval, and at least one value of the delivery rate measured while the content user is in the second radio state, after the first time interval.

(35) The disclosed exemplary embodiments provide controllers, methods and software for determining a manner in which multimedia content is delivered from a source proxy to a UE in a mobile network, while taking into consideration the user drop-out rate and using the UE battery efficiently. It should be understood that this description is not intended to limit the invention. On the contrary, the exemplary embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention. Further, in the detailed description of the exemplary embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the inventive concept. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.

(36) The exemplary embodiments may take the form of an entirely hardware embodiment or an embodiment combining hardware and software aspects. Further, the exemplary embodiments may take the form of a computer program product stored on a computer-readable storage medium having computer-readable instructions embodied in the medium. Any suitable computer readable medium may be utilized including hard disks, CD-ROMs, digital versatile disc (DVD), optical storage devices, or magnetic storage devices such a floppy disk or magnetic tape. Other non-limiting examples of computer readable media include flash-type memories or other known memories.

(37) Although the features and elements of the present exemplary embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein. The methods or flow charts provided in the present application may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a specifically programmed computer or processor.