WO2020094229A1

WO2020094229A1 - Video segment management

Info

Publication number: WO2020094229A1
Application number: PCT/EP2018/080527
Authority: WO
Inventors: Médéric BLESTEL
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2018-11-07
Filing date: 2018-11-07
Publication date: 2020-05-14

Abstract

Video segments of a video content are managed by determining (SI) a respective Lagrangian cost for time-aligned video segments from multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory (102, 121, 220). The video segment management also comprises determining (S2) whether to remove a video segment of the time-aligned video segments from the memory (102, 121, 220) based on the respective Lagrangian costs.

Description

VIDEO SEGMENT MANAGEMENT

TECHNICAL FIELD

The invention generally relates to method, device, computer program and carrier for managing video segments.

BACKGROUND

Services and vendors delivering video over the Internet have increased tremendously during the last years. Generally, video can be directly live streamed to user devices using, for instance, Digital Video Broadcasting - Terrestrial (DVB-T), DVB - Satellite (DVB-S) or Advanced Television Systems Committee (ATSC) or processed to address different user devices using adaptive streaming.

Fig. 1 illustrates an overview of a system used to deliver video using adaptive streaming. A video encoder receives a video sequence, such as in the form of a live stream, and encodes the video sequence using different representations, also referred to as profiles in the art, to generate bitstreams with different resolutions and target bit rates. A representation means a configuration, in which the video content is encoded, i.e., using a given resolution and a given bit rate. For each representation, the video encoder generates a bitstream, which can be directly broadcasted, or transformed to be compliant with adaptive streaming.

Generally, all bitstreams output by the video encoder are chopped or divided into small portions or segments of video content, sometimes referred to as short video chunks or simply chunks, by a packager. Each such portion containing a short interval of playback time, such as a few seconds, is packaged into video segments, also referred to as media segments, according to various adaptive streaming techniques, such as Dynamic Adaptive Streaming over Hypertext Transfer Protocol (HTTP) (DASH), also referred to as MPEG-DASH; HTTP Live Streaming (HLS); HTTP Dynamic Streaming (HDS); Smooth Streaming; QuavStreams Adaptive Streaming over HTTP; and upLynk HD Adaptive Streaming. These video segments are then stored at a HTTP server. The HTTP server is in charge of streaming all requested video segments to user devices through various network infrastructures.

A video player, present in or executed on a user device, automatically selects the next video segment to download from the HTTP server and to play based on current network conditions. Generally, the video player selects the video segment with the highest possible bit rate that can be downloaded in time for playback without compromising playback, i.e., without causing stalls or re-buffering. A list of available bitstreams and video segments is present in a manifest file denoted Media Presentation Description (MPD).

In order to enable playback of the video in various conditions, i.e. using different types of user devices, e.g., TV, smartphone, computer, etc., connected through various network infrastructures, e.g., Local Area Network (LAN), Wi-Fi, 3G, 4G, 5G, etc., with different bandwidth capabilities, the video content is encoded using different resolutions and target bit rates. The higher the resolution and target bit rate, the more storage and bandwidth are needed to deliver the video content. Hence, a lot of video segments are generated and stored for a given video sequence or content. There is therefore a need to optimize the amount of video segments stored at the HTTP server for delivery to user devices.

US 2017/0374432 discloses a system for adaptive streaming that includes a video receiver configured to transmit a request for a video segment. A video analyzer is configured to determine, for the video segment, a quality equivalence map (QEM) between two or more bit rate levels. A video sender coupled to the video analyzer is configured to select a bit rate level for the video segment based on an available bandwidth and the determined QEM. The video segment at the selected bit rate level is transmitted to the video receiver.

US 2018/0270524 discloses a method in an encoder. The method comprises receiving a video and encoding a segment of the video in multiple representations at different bit rates and resolutions. The method also comprises generating a quality metric for each representation of the video segment and storing the lowest bit rate representation of the video segment for which the respective quality metric meets a predefined minimum quality threshold. SUMMARY

It is a general objective to provide a video segment management that reduces the amount of video segments required to be available for a video content at a streaming sever for delivery to user devices.

This and other objectives are met by aspects of the invention as well as embodiments as disclosed herein.

An aspect of the invention relates to a method of managing video segments of a video content. The method comprises determining a respective Lagrangian cost for time-aligned video segments from multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory. The method also comprises determining whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs. Another aspect of the invention relates to a device for managing video segments of a video content. The device is configured to determine a respective Lagrangian cost for time-aligned video segments from multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory. The device is also configured to determine whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

Related aspects of the invention define a streaming server and a network device comprising a device according to above. A further aspect of the invention relates to a computer program comprising instructions, which when executed by at least one processor, cause the at least one processor to determine a respective Lagrangian cost for time-aligned video segments from multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory. The at least one processor is also caused to determine whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

A related aspect of the invention defines a carrier comprising a computer program according to above. The carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

The present aspects of the invention improve video segment management by removing surplus video segments, thereby reducing the amount of video segments and data that needs to be forwarded to a streaming server and stored therein for a given video content. The surplus video segments are video segments that can be removed without any significant deterioration in video quality for the end user. These surplus video segments are identified based on Lagrangian costs thereby taking into account both the quality or distortion and the bit rate of each video segment.

BRIEF DESCRIPTION OF THE DRAWINGS The aspects as well as embodiments thereof, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which: Fig. 1 illustrates an overview of a system used to deliver video using adaptive streaming;

Fig. 2 is a flow chart illustrating a method of managing video segments according to an embodiment;

Fig. 3 is a flow chart illustrating an additional, optional step of the method shown in Fig. 2 according to an embodiment;

Fig. 4 is a flow chart illustrating step S2 of Fig. 2 according to various embodiments;

Fig. 5 is another flow chart illustrating step S2 of Fig. 2 according to various embodiments;

Fig. 6 is a flow chart illustrating an additional, optional step of the method shown in any of Figs. 3 to 5 according to an embodiment;

Fig. 7 is a flow chart illustrating an additional, optional step of the method shown in any of Figs. 2 to 6 according to another embodiment;

Fig. 8 is a flow chart illustrating an additional, optional step of the method shown in any of Figs. 2 to 6 according to an embodiment; Fig. 9 schematically illustrates video segments of multiple representations generated for a video content;

Fig. 10 illustrates selective removal of video segments according to various embodiments;

Fig. 1 1 illustrates streaming of video segments from different representations following the video segment removal shown in Fig. 10;

Fig. 12 is a diagram showing video quality versus bitrate for video segments from three different video contents (Case 1 -3); Fig. 13 is a block diagram of a device for managing video segments according to an embodiment;

Fig. 14 is a block diagram of a device for managing video segments according to another embodiment; Fig. 15 is a block diagram of a device for managing video segments according to a further embodiment;

Fig. 16 schematically illustrates a computer program based implementation of an embodiment;

Fig. 17 is a block diagram of a device for managing video segments according to another embodiment;

Fig. 18 is a block diagram of a streaming server according to an embodiment;

Fig. 19 schematically illustrates a distributed implementation among network devices; Fig. 20 is a schematic illustration of an example of a wireless communication system with one or more cloud-based network devices according to an embodiment;

Fig. 21 is a schematic diagram illustrating an example of a wireless network in accordance with some embodiments;

Fig. 22 is a schematic diagram illustrating an example of an embodiment of a wireless device in accordance with some embodiments;

Fig. 23 is a schematic block diagram illustrating an example of a virtualization environment in which functions implemented by some embodiments may be virtualized;

Fig. 24 is a schematic diagram illustrating an example of a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments; Fig. 25 is a schematic diagram illustrating an example of a host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments;

Fig. 26 is a flowchart illustrating a method implemented in a communication system in accordance with an embodiment; Fig. 27 is a flowchart illustrating a method implemented in a communication system in accordance with an embodiment; Fig. 28 is a flowchart illustrating a method implemented in a communication system in accordance with an embodiment; and

Fig. 29 is a flowchart illustrating a method implemented in a communication system in accordance with an embodiment.

DETAILED DESCRIPTION

Throughout the drawings, the same reference numbers are used for similar or corresponding elements.

The invention defines a management of video segments and in particular to such management of video segments in the context of adaptive streaming. In adaptive streaming, video content is encoded using different representations, also referred to as profiles in the art of video coding, to generate respective bitstreams, typically one such bitstream per representation. Each such representation defines a respective combination of resolution and target bit rate employed to encode the video content. Accordingly, the bitstreams are generated with different resolutions and target bit rates. A representation means a configuration in which the video content is encoded, i.e., using a given resolution and a given bit rate. The bitstreams output by the video encoder are typically chopped or divided into small portions, sometimes referred to as short video chunks or simply chunks, containing a short interval of playback time. These portions are then packaged into video segments and stored to be available for a HTTP server. The HTTP server is then in charge of streaming requested video segments to user devices through various network infrastructures.

In order to enable playback of the video content using various types of user devices connected through various network infrastructures with different bandwidth capabilities, the video content needs to be encoded in multiple, i.e. at least two, representations. Accordingly, a lot of video segments are generated and stored for each video content. Furthermore, these video segments need to be transmitted to the HTTP server, in particular if the segmentation of the bitstreams is performed by a separate device, such as exemplified by the packager in Fig. 1.

The invention improves the management of video segments by determining and identifying video segments that could be selectively removed, thereby reducing the amount of data that needs to be transmitted to the HTTP server and stored therein. Hence, the management of the video segments according to the invention reduces the amount of video segments that need to be stored and available to the user devices at the HTTP server but without any deterioration in the streaming services provided by the HTTP server.

Fig. 2 is a flow chart illustrating a method of managing video segments of a video content according to an embodiment. The method comprises determining, in step S1 , a respective Lagrangian cost for time-aligned video segments from multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time- aligned video segments are stored in a memory. The method also comprises determining, in step S2, whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

Hence, according to the invention, a video content or video sequence is encoded according to multiple representations, i.e., encoded at multiple combinations of resolution and target bit rate. For instance, a video content could be encoded according to four different representations P1-P4 with the representation Pi defining standard definition (SD) video with a resolution of 960x540 pixels and a target bit rate of 1300 kbps, the representation P2 defining SD video (960x540 pixels) and a target bit rate of 1850 kbps, the representation P3 defining high definition (HD) video with a resolution of 1280x720 pixels and a target bit rate of 2200 kbps and the representation P4 defining HD video (1280x720 pixels) and a target bit rate of 2500 kbps as illustrative, but non-limiting, examples.

Target bit rate as used herein refers to the maximum bit rate that the video segments of a given representation should have. Hence, the video encoder tries to encode the video content in a way to reach, but not exceed, the target bit rate for the given representation. In practice, one or more video segments from, of, belonging to or according to a representation may have an actual bit rate, also referred to as effective bit rate, that may be equal to or lower than the target bit rate defined by the representation. Table 1 below illustrates examples of actual bit rates of video segments from the above exemplified four representations

P1-P4.

Table 1 - Actual bit rates of video segments

For instance, as is seen in the example of Table 1 , the actual bit rate of video segment number 0, 2 and 3 (S01 , S21 , S31) from the representation Pi is equal to the target bit rate defined by this representation Pi , whereas the actual bit rate of video segment number 1 and 4 (Si 1 , S41) from this representation Pi is lower than the target bit rate. An actual bit rate of a video segment may be lower than the target bit rate if, for instance, the video encoder is able to efficiently encode the video data of that video segment, for instance if the video data is a so-called simple-to-encode video data.

Actual bit rate of a video segment represents the number of bits used to encode the video segment, which is also the number of bits used to store the video segment in a memory. The actual bit rate of a video segment can be measured by any device, such as the video encoder, the packager, a device for managing video segments, or any other device or processor. In some applications, the video segments could contain an information field with information of the actual bit rate. In such a case, no measurement or determination thereof is needed as the information could then be retrieved from the information field in the video segments. The management of video segments according to the invention and as shown in Fig. 2 operates on so-called time-aligned video segments. This is schematically shown in Fig. 9. Flence, video segments having a same video segment number but being from different representations are time-aligned and thereby having a same start time with regard to playback. Although the time-aligned video segments have a same start time as shown in Fig.9, they do not necessarily have to have a same size in terms of number of bits. In clear contrast, the video segments typically have different sizes in bits since they are encoded at different combinations of resolution and target bit rate. In a particular embodiment, time-aligned video segments have a same timestamp defining this start time.

Time aligning video segments from different representations enables user devices to switch between bitstreams encoded according to different representations during an ongoing streaming session. Hence, when the network conditions change, such as an increase or drop in the bandwidth available for streaming the video segments, the streaming of video segments can switch between representations and thereby between bitstreams. For instance, video segment numbers 0 and 1 from representation P2 are streamed to a user device from an HTTP server. The network conditions then change so that the available bandwidth increases. Hence, the streaming can then continue with video segment number 2 from representation P3 instead of video segment number 2 from representation P2. This representation P3 has a higher resolution and target bit as compared to the representation P2 and thereby typically the video content encoded according to this representation P3 is of a higher quality as compared to the video content encoded according to the representation P2.

In a typical embodiment, time-aligned video segments comprise the same video content of the video sequence but encoded according to different representations, i.e., according to different combinations of resolution and target bit rate. For instance, video segment number 0 from representations P1-P4 comprise video content corresponding to the time interval from to to ti in the video sequence, video segment number 1 from representations P1-P4 comprise video content corresponding to the time interval from ti to . in the video sequence, and so on.

The management of video segments and the decision of whether to remove any video segment from the memory is based on the Lagrangian costs determined for video segments in step S1 . The Lagrangian cost represents or defines a combination of distortion, or quality, and rate of a video segment. This means that the determination whether to remove a video segment in step S2 is based on the distortions and rates of the video segments, or equivalently based on the qualities and rates of the video segments.

Distortion (D) represents the loss of quality of video content during the encoding process. Thus, high distortion implies low quality and vice versa. The distortion could thereby be interpreted as being inversely proportional to the quality. This means that the Lagrangian cost (J) of a video segment can be determined either based on the distortion (D) and the rate (R) of the video segment, i.e., J = f( D, R ) for some function f( ), or based on the quality (Q) and the rate of the video segment, i.e., J = g( Q, R ) for some function g( ). In the following, the determination of the Lagrangian cost is described further with reference to distortion of a video segment. This is, however, equivalent to determining the Lagrangian cost based on the quality of the video segment.

In an embodiment, step S1 of Fig. 2 comprises determining Jnm - Dnm + xRnm. In this embodiment,

Jnm represents Lagrangian cost for video segment number n from representation number m (Pm), Dnm represents distortion of video segment number n from representation number m, Rnm denotes bit rate of video segment number n from representation number m and l is a Lagrange multiplier.

The distortion Dnm could be any distortion metric used to represent the loss of video quality in a video segment. Illustrative, but non-limiting, examples of distortion metrics that could be used include mean square error (MSE), sum of squared errors (SSE), sum of absolute differences (SAD), sum of absolute transformed differences (SATD), and sum of squared transformed differences (SSTD). Correspondingly, illustrative, but non-limiting, examples of video quality metrics include peak signal to noise ratio (PSNR), structural similarity (SSIM), multiscale SSIM (MS-SSIM), information content weighted PSNR (IW- PSNR), PSNR human visual system (PSNR-HVS), PSNR-HVS with contrast masking (PSNR-HVS-M), visual information fidelity (VI F) and video multi-method assessment fusion (VMAF).

In fact, it is possible to obtain distortion values from quality values and vice versa. For instance, Table 2 lists examples of distortion values for different SSIM and PSNR values.

Table 2 - distortion values for SSIM and PSNR values

The rate Rnm could be any bit rate metric. In an embodiment, the rate Rnm is the actual bit rate of video segment number n from representation number m. In another embodiment, the rate Rnm is the target bit rate of video segment number n from representation number m, i.e., the target bit rate defined by the representation number m (Pm). In a preferred embodiment, Rnm is the actual bit rate of video segment number n from representation number m.

The Lagrange multiplier l is included in the Lagrangian cost to achieve a weighted combination of the distortion and rate of the video segment. The actual value of the Lagrange multiplier l depends at least partly based on the particular distortion metric and the particular rate metric to use in the determination of the Lagrangian cost. The value of the Lagrange multiplier l could be defined and trained using, for instance, machine learning or neural networks. Today, a machine learning technique is used to fine tune video encoder decision by defining Lagrange multiplier l for a given distortion. For instance, the technique described in Li,“Qp refinement according to Lagrange multiplier for high efficiency video coding”, 2013 IEEE International Symposium on Circuits and Systems (ISAC2013), Beijing, 2013, pp. 477-480 could be used to determine the value of the Lagrange multiplier l used according to the invention.

In an embodiment, step S2 in Fig. 2 comprises determining whether to remove a video segment of the time-aligned video segments from the memory based on a comparison of the respective Lagrangian costs.

Thus, in this embodiment the Lagrangian costs determined in step S1 , or a portion of the determined Lagrangian costs, such as a pair of Lagrangian costs, are compared to each other and the decision whether to remove a video segment in step S2 is then based on such a comparison. This corresponds to performing the determination in step S2 based on Jnm and Jnp, wherein m and p indicate numbers of different representations (Pm and Pp). Thus, in a particular embodiment, step S2 in Fig. 2 comprises determining whether to remove a video segment of the time-aligned video segments from the memory based on a pairwise comparison of the respective Lagrangian costs. The pair of Lagrangian costs compared could be the Lagrangian costs determined for two time-aligned video segments number n from any of the representations, such as from representations Pm and Pp. In an embodiment, the Lagrangian costs compared with each other are determined for time-aligned video segments from neighboring representations, i.e., representations Pm and Pm+1 . In such a particular embodiment, the determination in step S2 is based on a comparison of Jnm and Jn(m+1 ).

In an embodiment, the method comprises an additional step S3 as shown in Fig. 3. The method continues from step S2 in Fig. 2. In this embodiment, step S2 preferably comprises identifying a video segment of the time-aligned video segments to remove from the memory based on the respective Lagrangian costs. The identified video segment is then removed from the memory in step S3. Flence, once it is determined to remove a video segment from the memory based on the Lagrangian costs this identified video segment is removed from the memory in step S3. As a consequence, the amount of data that is stored for a given video content is reduced due to the video segment removal.

In an embodiment, the video content is encoded according to at least a first representation and a second representation. In this embodiment, the first representation of the multiple representations has a lower target bit rate as compared to the second representation of the multiple representations. Hence, if the first representation has number m and the second representation has number p or (m+1 ) then TRnm <

TRnp or TRnm < TRn(m+1 ), wherein TRnm denotes target bit rate of video segment number n from representation number m.

In the following and in Figs. 4 and 5, the first representation is exemplified with representation number m, i.e., Pm, whereas the second representation is exemplified with representation number m+1 , i.e.,

Pm+1. The embodiments are, however, not limited thereto. In clear contrast, the second representation could generally have representation number p, i.e., Pp, wherein p is not necessarily equal to m+1 .

In an embodiment, step S2 in Fig. 2 is performed according to step S1 1 in Fig. 4 or 5, which show various embodiments of step S2. This step S1 1 comprises removing a video segment from the second representation from the memory if the Lagrangian cost determined for a video segment from the first representation is lower than the Lagrangian cost determined for the video segment from the second representation. This embodiment thereby corresponds to the case in which the Lagrangian cost is lower for the video segment from the first representation with lower target bit rate as compared to the Lagrangian cost for the video segment from the second representation. In this case, any quality gain provided with the higher target bit rate of the second representation is not significant. This is schematically illustrated as Case 2 in Fig. 12.

Fig. 12 illustrates video quality represented as SSIM for the color space luminance (Y) and chrominance (U, V) of a video segment with three different video contents (Case 1-3) encoded using various representations with different target bit rates. The first case, Case 1 , achieves a significant improvement in video quality for increasing target bit rates and therefore for increasing video segment sizes. For instance, when increasing the target bit rate from 1300 kbps to 2400 kbps the video quality metric continually increases by a significant step from 96.6 to 98.2. Case 2 illustrates a situation in which increasing the target bit from 1300 kbps to 2400 kbps has very limited impact on the video quality metric, in fact less than 0.15. This can occur for video contents with low motion scenes or low texture areas that are generally easy to encode. In this Case 2, as the benefit in terms of video quality is very limited and will not be subjectively noticeable, video segments with higher bit rates could be removed from the memory without any impact on the end user. Case 3 illustrates a situation where there is a substantial increase in video quality with a limited increase in target bit rate. Flence, increasing the target bit rate by 150 kbps from 1300 kbps to 1450 kbps increases the video quality metric by 1 , from 96.6 to 97.6.

In the embodiment of step S1 1 , the quality gain obtained by increasing the bit rate from TRnm to

TRn(m+1 ) does not lead to any significant increase in video quality and thereby does not lead to any significant decrease in distortion as shown in Case 2 in Fig. 12. As a consequence, the Lagrangian cost Jnm determined for the video segment Snm from the first representation Pm will be lower than the Lagrangian cost Jn(m+1 ) determined for the video segment Sn(m+1 ) from the second representation

P(m+1 ). In this embodiment, the video segment Sn(m+1 ) from the second representation P(m+1 ) with the higher target bit rate can thereby be removed from the memory in step S11 .

In an embodiment, step S2 comprises an additional step S10 as shown in Figs. 4 and 5. This step S10 comprises comparing the Lagrangian cost Jnm determined for the video segment Snm from the first representation Pm with the Lagrangian cost Jn(m+1 ) determined for the video segment Sn(m+1) from the second representation P(m+1 ). If Jnm < Jn(m+1 ), then the method continues to step S1 1 , where the video segment Sn(m+1 ) from the second representation P(m+1 ) is removed from the memory. This situation is further shown in Fig. 10 where the Lagrangian costs for video segments S23 and S24 are compared with the result J23 < J24. As a consequence, the video segment S24 from the representation P4 can be removed from the memory as indicated in the figure. In another embodiment, step S2 in Fig. 2 is performed according to step S13 in Fig. 4 or 5. This step S13 comprises removing a video segment from the first representation from the memory if the Lagrangian cost determined for a video segment from the second representation is equal to or lower than the Lagrangian cost determined for the video segment from the first representation and if an actual bit rate of the video segment from the second representation is equal to or lower than the target bit rate of the first representation.

In this embodiment, the Lagrangian cost Jn(m+1 ) determined for the video segment Sn(m+1 ) from the second representation P(m+1 ) is equal to or lower than the Lagrangian cost Jnm determined for the video segment Snm from the first representation Pm, i.e., Jn(m+1 ) < Jnm. This is the expected behavior since generally an increase in bit rate leads to an increase in video quality and thereby a decrease in distortion. However, the video segment Snm from the first representation Pm is in this embodiment only removed from the memory if a second condition is met, i.e., the actual bit rate Rn(m+1 ) of the video segment Sn(m+1 ) from the second representation Pm+1 is equal to or lower than the target bit rate TRnm of the first representation Pm, i.e., Rn(m+1 ) < TRnm.

In an embodiment, step S2 comprises the previously mentioned additional step S10 as shown in Figs. 4 and 5. If Jnm is not smaller than Jn(m+1 ), i.e., if Jn(m+1 ) < Jnm, then the method continues to an additional step S12 as shown in Fig. 4 or an additional step S14 as shown in Fig. 5. Step S12 comprises comparing the actual bit rate Rn(m+1 ) of the video segment Sn(m+1 ) from the second representation Pm+1 with the target bit rate TRnm of the first representation Pm. If Rn(m+1 ) < TRnm, then the method continues to step S13, where the video segment Snm from the first representation Pm is removed from the memory. Fig. 5 illustrates an additional, optional comparison step S14, which compares the two Lagrangian costs to determine whether they are equal, i.e., Jn(m+1) = Jnm. If step S14 determines that the two Lagrangian costs are not equal, i.e., Jn(m+1) < Jnm, then the method continues to step S12. This situation corresponds to Case 3 in Fig. 12, in which a comparatively small increase in bit rate results in a comparatively large increase in video quality and thereby a comparatively large decrease in distortion.

Fig. 10 also illustrates this situation where the Lagrangian costs for video segments S11 and S12 are compared with the result J12 < J11. Furthermore, R12 is 800 kbps, see Table 1 , which is lower than TR11 of 1300 kbps. Hence, the video segment S11 from the first representation Pi can be removed from the memory as indicated in the figure. Furthermore, the Lagrangian cost for video segment S12 is also compared with the Lagrangian cost for video segment S13 with the result J13 < J12. Furthermore, R13 is 1300 kbps, see Table 1 , which is lower than TR12 of 1850 kbps and also equal to TR11 of 1300 kbps. Hence, the video segment S12 from the second representation P2 can be removed from the memory as indicated in the figure.

In a further embodiment, step S2 in Fig. 2 is performed according to step S16 or S17 in Fig. 5. Step S16 comprises removing a video segment from the second representation from the memory if the Lagrangian cost determined for a video segment from first representation is equal to the Lagrangian cost determined for the video segment from the second representation and if an actual bit rate of the video segment from the first representation is lower than an actual bit rate of the video segment from the second representation. Correspondingly, step S17 comprises removing the video segment from the first representation from the memory if the Lagrangian cost determined for the video segment from first representation is equal to the Lagrangian cost determined for the video segment from the second representation and if the actual bit rate of the video segment from the first representation is equal to or higher than the actual bit rate of the video segment from the second representation.

In this embodiment, the Lagrangian cost Jnm determined for the video segment Snm from the first representation Pm is equal to the Lagrangian cost Jn(m+1) determined for the video segment Sn(m+1) from the second representation Pm+1 , i.e., Jnm = Jn(m+1). If the actual bit rate Rnm of the video segment Snm from the first representation Pm is lower than the actual bit rate Rn(m+1) of the video segment Sn(m+1) from the second representation Pm+1 , i.e., Rnm < Rn(m+1), then the video segment Sn(m+1) from the second representation Pm+1 is removed from the memory in step S16 otherwise, i.e., Rnm > Rn(m+1), the video segment Snm from the first representation Pm is removed from the memory in step S17.

Fig. 10 also illustrates this situation where the Lagrangian costs for video segments S21 and S22 and S31 and S32 and are compared with the result J21 = J22 and J31 = J32. Furthermore, R21 and R31 are both 1300 kbps, see Table 1 , which is equal to R22 and R32 of 1300 kbps. Flence, video segments S21 and S31 from the representation Pi can be removed from the memory as indicated in the figure.

In Figs. 4 and 5, step S10 comprises comparing the Lagrangian costs Jnm and Jn(m+1) and determining whether Jnm < Jn(m+1). This comparison could alternative determine whether Jn(m+1) > Jnm. If Jn(m+1) > Jnm as determined in step S10 the method continues to step S12 in Fig. 3 or step S14 in Fig. 4, otherwise it continues to step S1 1.

Furthermore, the order at which comparisons of Lagrangian costs are performed in Fig. 5 may change. Hence, step S14 could be performed prior to or at least substantially in parallel with step S10.

The following pseudo-code represents an embodiment of managing video segments according to the invention. The pseudo-code presumes that the Lagrangian costs are available for the video segments. Alternatively, the Lagrangian costs could be determined within the for-loops. In this example, there are N+1 video segments per representation and M representations. for( n = 0; n < N+1 ; n++ ) {

for( m = 1 ; m < M; m++ ) {

if( J nm < Jn(m+1) ) { remove Sn(m+1); }

elseif(Jnm ⁼ Jn(m+1 ) ) { if( Rnm < Rn(m+1 ) ) { remove Sn(m+1 );

}

else {

remove Snm;

}

else {

if( Rn(m+1 ) £ TRnm ) { remove Snm;

}

Fig. 9 illustrates the video segments from the four representations presented in Table 1 prior to the management of video segments of the invention and prior to segment removal or pruning. Fig. 10 illustrates video segments identified according to the invention using Lagrangian costs and that can be removed without any deterioration in the quality for the end user. Fig. 1 1 illustrates the remaining video segments from the four representations after video segments have been removed.

A media presentation description (MPD) is preferably updated following removal of any video segment. The MPD is a manifest file comprising information of the available bitstreams and video segment. In particular, the MPD describes video segment information, such as timing, Uniform Resource Locator (URL), video resolutions and target bit rates.

The MPD is used by the user device, and in particular a video player present in or executed on the user device, in order to select video segments of a video content to download from the HTTP server based on the current network conditions. This is schematically illustrated in the diagram of quality vs. time to the right in Fig. 1 showing that video segments from different representations and bitstreams are downloaded from the HTTP server to the user device depending on variations in the network conditions, such as bandwidth, of the network used to deliver the video segments from the HTTP server to the user device.

Fig. 6 is a flow chart illustrating an additional step S20 relating to the update of the MPD. The method continues from step S3 in Fig. 3 or from any of the steps S1 1 , S13, S16 or S17 in Fig. 4 or 5. Step S20 in Fig. 6 comprises updating a media presentation description comprising information of the multiple representations and the time-aligned video segments by replacing information of the removed video segment from the first representation or from the second representation with information of the video segment from the second representation or from the first representation in the media presentation description.

Hence, if a video segment from the first representation is removed, such as performed in step S13 and S17 of Figs. 4 and 5, information of this removed video segment is replaced with information of the video segment from the second representation. Correspondingly, if a video segment from the second representation is removed, such as performed in step S1 1 and S16 of Figs. 4 and 5, information of this removed video segment is replaced with information of the video segment from the first representation.

Replacing information of video segments in the MPD implies that the information of a removed video segment, such as its timing, URL, video resolution and bit rate, is replaced by the corresponding information of the video segment that is to be used instead of the removed video segment. This is schematically illustrated in Fig. 1 1 . For instance, following video segment removal, the video segments available for the first representation are Soi , S13, S22, S32 and S41. The video segments available for the second representation are S02, S13, S22, S32 and S42 and the following video segments are available for the third representation S03, Si 3, S23, S33 and S43. Finally, the video segments available for the fourth representation are S04, S14, S23, S34 and S44.

In another embodiment, step S20 of Fig. 6 comprises updating a media presentation description comprising information of the multiple representations and the time-aligned video segments by removing information of the removed video segment from the media presentation description.

In this embodiment, the information of the removed video segment does not necessarily has to be replaced by the information of another remaining time-aligned video segment from another representation. The MPD may, for instance, instead include a pointer at the information field corresponding to the removed video segment pointing towards the information field of the time-aligned video segment from another representation that is to be used instead of the removed video segment. Hence, in this embodiment, the information does not necessarily have to be copied between information fields in the MPD but pointers or other elements could be used to refer to the correct information in the MPD. For instance, the information field corresponding to the removed video segment Si 1 from the first presentation Pi in Fig. 1 1 could include a pointer to the video segment S13 from the third presentation P13.

The video segment management of the invention could be performed by various devices in a system used to deliver video to user devices, preferably using adaptive streaming. For instance, the video segment management could be performed by a device responsible for chopping or dividing the bitstreams output by a video encoder into smaller portions and packaging them into video segments. This device could for instance be the packager as illustrated in Fig. 1 and arranged in the process chain between the video encoder and the HTTP server. In such a case, the packager comprises a memory storing the video segments from the different presentations and bitstreams. The packager also performs the video segment management to determine whether video segments can be removed from the memory. This means that following the video management, the number of video segments and thereby the amount of data stored in the memory of the packager for a given video content will thereby typically be less as compared to the original number of video segments, compare for instance Figs. 9 and 1 1 . This also means that the number of video segments and the amount of data that the packager forwards to the HTTP server will be lower when performing the video segment management of the invention. Furthermore, the number of video segments and amount of data that the HTTP server will store will correspondingly be less when using the invention. In another embodiment, the management of video segments according to the invention is performed by or at the HTTP server. In this case, the full amount of video segments are delivered from the packager to the HTTP server and stored in a memory therein. The HTTP server then performs the video segment management of the invention to remove any surplus video segments and thereby reduce the amount of data that needs to be stored at the HTTP server for the video content. As compared to performing the video segment management in the packager, this embodiment implies that more data needs to be sent from the packager to the HTTP server as compared to doing the video segment management already at the packager. A further embodiment is to perform the video segment management in a device or functionality different from the device performing the segment chopping and packaging, i.e., the packager in Fig. 1 , and different from the HTTP server. This device may then be implemented in the process chain of Fig. 1 downstream of the packager but upstream of the HTTP server with regard to the direction indicated by the arrows in the figure. The packager then transmits all video segments from the different representations and bitstream to this device for storage therein in a memory. The device then performs the video segment management of the invention to remove any surplus video segments. The device can then forward the reduced number of video segments to the HTTP server. Fig. 8 is a flow chart illustrating an additional, optional step of the method shown in any of Figs. 2 to 6. In this embodiment, the method comprises forwarding, in step S40, the video segments from the memory to a streaming server. This embodiment thereby relates to the above described cases of implementing the video segment management of the invention in a device different from the HTTP server, such as in the packager or in another device. Thus, remaining video segments from the representations following any video segment removal are forwarded from the memory to the streaming server, such as HTTP server, where they are available for delivery to requesting user devices.

Fig. 7 is a flow chart illustrating an additional, optional step of the method shown in any of Figs. 2 to 6. In this embodiment, the method comprises streaming, in step S30, the encoded video content using adaptive bit rate streaming. Hence, video segments are delivered to user devices based on requests therefrom. The user devices can select which video segment, i.e., from which representation and bitstream, to download based on information in the MPD and based on information of current network conditions. Generally, a user device requests the video segment with the highest possible bit rate that can be downloaded in time for playback without compromising playback, i.e., without causing stalls or re- buffering. The MPD comprises the necessary information of the video segments and bitstreams and this MPD is preferably updated following any video segment removal as previously described herein to thereby only contain information of those video segments that are actually available at the HTTP server following the video segment management of the invention. The streaming of encoded video content in step S30 comprises, in an embodiment, streaming encoded video content from the first representation or from the second representation by selecting the video segment from the second representation or from the first representation as a replacement of the removed video segment from the first representation or from the second representation. Fig. 9 indicates streaming of video segments from the different representations by the hatched arrows. Thus, without any video segment management or removal, if a given representation or bitstream is requested the video segments of that representation or bitstream are streamed to the user device, such as by streaming video segments Sol, S11 , S21 , S31 and S41 if the representation Pi is requested. Fig. 1 1 also indicates streaming of video segments but following the video segment removal shown in Fig. 10. This means that if the first representation Pi is requested then the video segments S01 , S13,

S22, S32 and S41 are instead streamed since the video segments S11 , S21 and S31 have been removed in the video segment management. This means that if a video segment from the first representation is removed, such as performed in step S13 and S17 of Figs. 4 and 5, the encoded video content from the first representation is streamed in step S30 by selecting the video segment from the second representation as a replacement of the removed segment from the first representation. Correspondingly, if a video segment from the second representation is removed, such as performed in step S11 and S16 of Figs. 4 and 5, the encoded video content from the second representation is streamed in step S30 by selecting the video segment from the first representation as a replacement of the removed segment from the second representation.

In particular embodiment, step S1 in Fig. 2 comprises determining a respective Lagrangian cost for video segments from at least three representations. In this particular embodiment, step S2 preferably comprises repeating determining whether to remove a video segment of the time-aligned video segments from the memory for each pair of representations based on the respective Lagrangian costs determined for the video segments from the pair of representations.

Hence, in a particular embodiment video segments are processed pairwise in the video segment management and the Lagrangian costs determined for such a pair of video segments are compared to determine whether to remove any of the two video segments. For instance, a video segment from representation number m is processed together with a time-aligned video segment from representation number m+1 as previously described herein. This means that in a first round, the decision of whether to remove any video segment from the video segment is based on Jni and Jn2, in a second round based on Jn2 and Jn3, and so on. In an embodiment, the representations are sorted in order of increasing target bit rate. Thus, TRnm <

TRn(m+l). The video segment management can, however, be performed also between non-sorted representations or if the representations are sorted based on some other parameter than target bit rate. In a variant of step S13 in Fig. 4 or 5 as applied to the case of pairwise comparisons between representations sorted in order of increasing target bit rate, step S13 comprises removing a video segment from the first representation from the memory if the Lagrangian cost determined for a video segment from the second representation is equal to or lower than the Lagrangian cost determined for the video segment from the first representation and if an actual bit rate of the video segment from the second representation is equal to or lower than the target bit rate of each representation of the multiple representations having equal or lower target bit rate as compared to the second representation.

In a further embodiment, the following processing of video segments can be performed. For a given video sequence number or time, all time-aligned video segments from the multiple representations are marked as “unused”. In a second step, Lagrangian costs determined for the video segments are, preferably pairwise, compared to identify video segments that could be removed. In this second step, video segments are marked as“used” if no removal thereof is requested. Once a video segment is marked as“used” it could not be marked as“unused” in a subsequent Lagrangian cost comparison. For instance, when comparing Jnl and Jn2, the video segment Sn2 may be marked as“used”. In such a case, when comparing Jn2 and Jn3, it is not possible to remark video segment Sn2 as“unused”. Once the (pairwise) Lagrangian cost comparisons are completed for all video segments of the given video segment number, any video segments marked as “unused” are removed from the memory.

The invention improves the video segment management by reducing the amount of bandwidth consumption and the amount of video segments to be stored before being delivered to user devices using adaptive streaming techniques. The invention improves the removal or pruning technique by taking into account both the quality, as represented by distortion, and the bit rate of each video segment, hence based on a trade-off between video segments quality and size. An advantage of the invention is that it can be implemented in current streaming systems in various devices, such as packager, HTTP server or separate device. The invention is completely codec agnostic, i.e., works with any video encoder, including video encoders for MPEG-2, also referred to as H.262; H.263; MPEG-4 Advanced Video Coding (AVC), also referred to as H.264 and MPEG-4 Part 10; High Efficiency Video Coding (HEVC), also referred to as H.265 and MPEG-H Part 2; and Versatile Video coding (WC). The invention is also adaptive streaming agnostic and can thereby be used according to various adaptive streaming techniques, such as Dynamic Adaptive Streaming over HTTP (DASH), also referred to as MPEG-DASH, HTTP Live Streaming (HLS), HTTP Dynamic Streaming (HDS), Smooth Streaming, QuavStreams Adaptive Streaming over HTTP, and upLynk HD Adaptive Streaming.

The invention allows video segment removal in more cases than merely removing video segments with exact the same size. For instance, the invention will remove video segments with a bit rate overhead but without any benefits at the quality level. Today, given the diversity of video contents complexity, a defined representation cannot guarantee the best video quality, and leads to waste storage and bandwidth in some cases when the bit rate goes beyond what is necessary to achieve a perceptible improvement in video quality. This corresponds to Case 2 in Fig. 12, in which increasing the video segment bit rate from 1300 kbps to 2400 kbps had a very limited impact on the video quality. This case can occur for video contents with low motion scenes or low texture areas like talking heads in news, TV shows and movies. In this case, as the benefit in terms of video quality metric is very limited and will not be subjectively noticeable, video segments with higher bitrates could be removed without any impact on the end user. On the other hand, while comparing video segments, the invention is also able to identify a substantial increase in the video quality with a limited bit rate increase as exemplified in Case 3 in Fig. 12. With respect to not compromising the video content delivery, i.e., without any buffering problems or stalls, the invention enables removal of the video segment with lowest bitrate. Consequently, by delivering a video segment with a slightly higher bit rate, the video player at the user device would display a video with a higher objective and subjective video quality. The case can occur, for instance, when comparing two video segments with different resolutions (not exclusively), and where streaming a video content with a higher resolution would benefit the end user.

US 2017/0374432 discloses a video segment pruning based on a quality equivalence map (QEM). The QEM can then be used to identify a lower bit rate level with an equivalent perceived quality for a video segment. A bit rate level for a video segment may be selected by determining the highest bit rate level allowed by the available bandwidth and selecting the lowest bit rate level with an equivalent perceived quality to the determined highest bit rate level.

Applying the video segment pruning based on QEM according to US 2017/0374432 to the example shown in Fig. 9 and Table 1 would imply that video segments S22 and S32 are removed instead of video segments S21 and S31 according to invention. Furthermore, the QEM-based video segment pruning cannot address the video segment removal of video segments Si 1 and S12 since it does not consider the actual bit rates of video segments but rather the target bit rates of the representations. This means that the video segment management of the invention achieves a different, and in most cases, a more efficient video segment management by removing more video segments as compared to the QEM-based video segment pruning according to US 2017/0374432.

Another aspect of the invention relates to a device for managing video segments of a video content. The device is configured to determine a respective Lagrangian cost for time-aligned video segments of multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory. The device is also configured to determine whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs. In an embodiment, the device is configured to determine Jnm - Dnm + xRnm.

In an embodiment, the device is configured to determine whether to remove a video segment of the time- aligned video segments from the memory based on a comparison of the respective Lagrangian costs. In an embodiment, the device is configured to identify a video segment of the time-aligned video segments to remove from the memory based on the respective Lagrangian costs. In this embodiment, the device is also configured to remove the identified video segment from the memory.

In an embodiment, the device is configured to update a media presentation description comprising information of the multiple representations and the time-aligned video segments by removing information of the removed video segment from the media presentation description.

In an embodiment, the device is configured to forward the video segments from the memory to a streaming server.

In an embodiment, the device is configured to stream the encoded video content using adaptive bit rate streaming. In an example embodiment, a first representation of the multiple representations has a lower target bit rate as compared to a second representation of the multiple representations.

In a variant of this example embodiment, the device is configured to remove a video segment from the second representation from the memory if the Lagrangian cost determined for a video segment from the first representation is lower than the Lagrangian cost determined for the video segment from the second representation.

Alternatively, or in addition, the device is configured to remove a video segment from the first representation from the memory if the Lagrangian cost determined for a video segment from the second representation is equal to or lower than the Lagrangian cost determined for the video segment from the first representation and if an actual bit rate of the video segment from the second representation is equal to or lower than the target bit rate of the first representation. Alternatively, or in addition, the device is configured to remove a video segment from the second representation from the memory if the Lagrangian cost determined for a video segment from the first representation is equal to the Lagrangian cost determined for the video segment from the second representation and if an actual bit rate of the video segment from the first representation is lower than an actual bit rate of the video segment from the second representation. Alternatively, or in addition, the device is configured to remove the video segment from the first representation from the memory if the Lagrangian cost determined for the video segment from the first representation is equal to the Lagrangian cost determined for the video segment from the second representation and if the actual bit rate of the video segment from the first representation is equal to or higher than the actual bit rate of the video segment from the second representation.

In an embodiment, the device is configured to update a media presentation description comprising information of the multiple representations and the time-aligned video segments by replacing information of the removed video segment from the first representation or from the second representation with information of the video segment from the second representation or the first representation in the media presentation description.

In an embodiment, the device is configured to stream the encoded video content from the first representation or from the second representation by selecting the video segment from the second representation or from the first representation as a replacement of the removed video segment from the first representation or from the second representation.

In an embodiment, the device is configured to determine a respective Lagrangian cost for video segments from least three representations. The device is also configured to repeat determining whether to remove a video segment of the time-aligned video segments from the memory for each pair of representations, optionally but preferably sorted in order of increasing target bit rate, based on the respective Lagrangian costs determined for the video segments of the pair of representations. It will be appreciated that the methods, method steps and devices, device functions described herein can be implemented, combined and re-arranged in a variety of ways.

For example, embodiments may be implemented in hardware, or in software for execution by suitable processing circuitry, or a combination thereof.

The steps, functions, procedures, modules and/or blocks described herein may be implemented in hardware using any conventional technology, such as discrete circuit or integrated circuit technology, including both general-purpose electronic circuitry and application-specific circuitry. Alternatively, or as a complement, at least some of the steps, functions, procedures, modules and/or blocks described herein may be implemented in software such as a computer program for execution by suitable processing circuitry such as one or more processors or processing units.

Examples of processing circuitry includes, but is not limited to, one or more microprocessors, one or more Digital Signal Processors (DSPs), one or more Central Processing Units (CPUs), video acceleration hardware, and/or any suitable programmable logic circuitry such as one or more Field Programmable Gate Arrays (FPGAs), or one or more Programmable Logic Controllers (PLCs).

It should also be understood that it may be possible to re-use the general processing capabilities of any conventional device or unit in which the proposed technology is implemented. It may also be possible to re-use existing software, e.g., by reprogramming of the existing software or by adding new software components. Fig . 13 is a schematic block diagram illustrating an example of a device 100 for managing video segments of a video content according to an embodiment. In this particular example, the device 100 comprises a processor 101 , such as processing circuitry, and a memory 102. The memory 102 comprises instructions executable by the processor 101 .

In an embodiment, the processor 101 is operative to determine the respective Lagrangian cost for time- aligned video segments. The processor 101 is also operative to determine whether to remove a video segment of the time-aligned video segments from the memory 102 based on the respective Lagrangian costs.

Optionally, the device 100 may also include a communication circuit, represented by a respective input/output (I/O) unit 103 in Fig. 13. The I/O unit 103 may include functions for wired and/or wireless communication with other devices, servers and/or network nodes in a wired or wireless communication network. In a particular example, the I/O unit 103 may be based on radio circuitry for communication with one or more other nodes, including transmitting and/or receiving information. The I/O unit 103 may be interconnected to the processor 101 and/or memory 102. By way of example, the I/O unit 103 may include any of the following: a receiver, a transmitter, a transceiver, I/O circuitry, input port(s) and/or output port(s). Fig. 14 is a schematic block diagram illustrating a device 1 10 for managing video segments of a video content based on a hardware circuitry implementation according to an embodiment. Particular examples of suitable hardware circuitry include one or more suitably configured or possibly reconfigurable electronic circuitry, e.g., Application Specific Integrated Circuits (ASICs), FPGAs, or any other hardware logic such as circuits based on discrete logic gates and/or flip-flops interconnected to perform specialized functions in connection with suitable registers (REG), and/or memory units (MEM).

Fig. 15 is a schematic block diagram illustrating yet another example of a device for managing video segments of a video content based on combination of both processor(s) 122, 123 and hardware circuitry 124, 125 in connection with suitable memory unit(s) 121 . The overall functionality is, thus, partitioned between programmed software for execution on one or more processors 122, 123 and one or more preconfigured or possibly reconfigurable hardware circuits 124, 125. The actual hardware-software partitioning can be decided by a system designer based on a number of factors including processing speed, cost of implementation and other requirements. Fig. 16 is a computer program based implementation of a device 200 for managing video segments of a video content according to an embodiment. In this particular example, at least some of the steps, functions, procedures, modules and/or blocks described herein are implemented in a computer program 240, which is loaded into the memory 220 for execution by processing circuitry including one or more processors 210. The processor(s) 210 and memory 220 are interconnected to each other to enable normal software execution. An optional I/O unit 230 may also be interconnected to the processor(s) 210 and/or the memory 220 to enable input and/or output of relevant data, such as video segments and bitstreams of encoded video content. The term‘processor’ should be interpreted in a general sense as any circuitry, system or device capable of executing program code or computer program instructions to perform a particular processing, determining or computing task.

The processing circuitry including one or more processors 210 is thus configured to perform, when executing the computer program 240, well-defined processing tasks such as those described herein.

The processing circuitry does not have to be dedicated to only execute the above-described steps, functions, procedure and/or blocks, but may also execute other tasks. In an embodiment, the computer program 240 comprises instructions, which when executed by at least one processor 210, cause the at least one processor 210 to determine a respective Lagrangian cost for time-aligned video segments of multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory 220. The at least one processor 210 is also caused to determine whether to remove a video segment of the time-aligned video segments from the memory 220 based on the respective Lagrangian costs.

The proposed technology also provides a carrier 250 comprising the computer program 240. The carrier 250 is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

By way of example, the software or computer program 240 stored on a computer-readable storage medium, such as the memory 220, in particular a non-volatile medium. The computer-readable medium may include one or more removable or non-removable memory devices including, but not limited to a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc (CD), a Digital Versatile Disc (DVD), a Blu-ray disc, a Universal Serial Bus (USB) memory, a Hard Disk Drive (HDD) storage device, a flash memory, a magnetic tape, or any other conventional memory device. The computer program 240 may, thus, be loaded into the operating memory 220 for execution by the processing circuitry 210.

The flow diagram or diagrams presented herein may be regarded as a computer flow diagram or diagrams, when performed by one or more processors. A corresponding device may be defined as a group of function modules, where each step performed by the processor corresponds to a function module. In this case, the function modules are implemented as a computer program running on the processor.

The computer program residing in memory may, thus, be organized as appropriate function modules configured to perform, when executed by the processor, at least part of the steps and/or tasks described herein.

Fig. 17 is a block diagram of a device 130 for managing video segments of a video content. The device 130 comprises a Lagrangian cost determining module 131 for determining a respective Lagrangian cost for time-aligned video segments of multiple representations. Each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation. The time-aligned video segments are stored in a memory. The device 130 also comprises a determining module 132 for determining whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

A further aspect relates to a streaming server 140, such as an HTTP server, comprising a device 100, 1 10, 120, 130 for managing video segments of a video content according to the invention, such as described in connection with any of Figs. 13 to 17.

It is also becoming increasingly popular to provide computing services (hardware and/or software) in network devices, such as network nodes and/or servers, where the resources are delivered as a service to remote locations over a network. By way of example, this means that functionality, as described herein, can be distributed or re-located to one or more separate physical nodes or servers. The functionality may be re-located or distributed to one or more jointly acting physical and/or virtual machines that can be positioned in separate physical node(s), i.e., in the so-called cloud. This is sometimes also referred to as cloud computing, which is a model for enabling ubiquitous on-demand network access to a pool of configurable computing resources, such as networks, servers, storage, applications and general or customized services.

There are different forms of virtualization that can be useful in this context, including one or more of:

• Consolidation of network functionality into virtualized software running on customized or generic hardware. This is sometimes referred to as network function virtualization.

• Co-location of one or more application stacks, including operating system, running on separate hardware onto a single hardware platform. This is sometimes referred to as system virtualization, or platform virtualization.

• Co-location of hardware and/or software resources with the objective of using some advanced domain level scheduling and coordination technique to gain increased system resource utilization. This is sometimes referred to as resource virtualization, or centralized and coordinated resource pooling.

Although it may often desirable to centralize functionality in so-called generic data centers, in other scenarios it may in fact be beneficial to distribute functionality over different parts of the network.

A network device may generally be seen as an electronic device being communicatively connected to other electronic devices in the network. By way of example, the network device may be implemented in hardware, software or a combination thereof. For example, the network device may be a special-purpose network device or a general purpose network device, or a hybrid thereof.

A special-purpose network device may use custom processing circuits and a proprietary operating system (OS), for execution of software to provide one or more of the features or functions disclosed herein. A general purpose network device may use common off-the-shelf (COTS) processors and a standard OS, for execution of software configured to provide one or more of the features or functions disclosed herein. By way of example, a special-purpose network device may include hardware comprising processing or computing resource(s), which typically include a set of one or more processors, and physical network interfaces (Nls), which sometimes are called physical ports, as well as non-transitory machine readable storage media having stored thereon software. A physical Nl may be seen as hardware in a network device through which a network connection is made, e.g. wirelessly through a wireless network interface controller (WNIC) or through plugging in a cable to a physical port connected to a network interface controller (NIC). During operation, the software can be executed by the hardware to instantiate a set of one or more software instance(s). Each of the software instance(s), and that part of the hardware that executes that software instance, may form a separate virtual network element.

By way of another example, a general purpose network device may, for example, include hardware comprising a set of one or more processor(s), often COTS processors, and NIC(s), as well as non- transitory machine readable storage media having stored thereon software. During operation, the processor(s) executes the software to instantiate one or more sets of one or more applications. While one embodiment does not implement virtualization, alternative embodiments may use different forms of virtualization - for example represented by a virtualization layer and software containers. For example, one such alternative embodiment implements operating system-level virtualization, in which case the virtualization layer represents the kernel of an operating system, or a shim executing on a base operating system, that allows for the creation of multiple software containers that may each be used to execute one of a set of applications. In an example embodiment, each of the software containers, also called virtualization engines, virtual private servers, or jails, is a user space instance, typically a virtual memory space. These user space instances may be separate from each other and separate from the kernel space in which the operating system is executed. Then, the set of applications running in a given user space, unless explicitly allowed, cannot access the memory of the other processes. Another such alternative embodiment implements full virtualization, in which case: 1 ) the virtualization layer represents a hypervisor, sometimes referred to as a Virtual Machine Monitor (VMM), or the hypervisor is executed on top of a host operating system; and 2) the software containers each represent a tightly isolated form of software container called a virtual machine that is executed by the hypervisor and may include a guest operating system.

A hypervisor is the software/hardware that is responsible for creating and managing the various virtualized instances and in some cases the actual physical hardware. The hypervisor manages the underlying resources and presents them as virtualized instances. What the hypervisor virtualizes to appear as a single processor may actually comprise multiple separate processors. From the perspective of the operating system, the virtualized instances appear to be actual hardware components.

A virtual machine is a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine; and applications generally do not know they are running on a virtual machine as opposed to running on a“bare metal” host electronic device, though some systems provide para-virtualization which allows an operating system or application to be aware of the presence of virtualization for optimization purposes. The instantiation of the one or more sets of one or more applications as well as the virtualization layer and software containers if implemented, are collectively referred to as software instance(s). Each set of applications, corresponding software container if implemented, and that part of the hardware that executes them (be it hardware dedicated to that execution and/or time slices of hardware temporally shared by software containers), forms a separate virtual network element(s).

The virtual network element(s) may perform similar functionality compared to Virtual Network Element(s) (VNEs). This virtualization of the hardware is sometimes referred to as Network Function Virtualization (NFV)). Thus, NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which could be located in data centers, network devices, and Customer Premise Equipment (CPE). Flowever, different embodiments may implement one or more of the software container(s) differently. For example, while embodiments are illustrated with each software container corresponding to a VNE, alternative embodiments may implement this correspondence or mapping between software container-VNE at a finer granularity level. It should be understood that the techniques described herein with reference to a correspondence of software containers to VNEs also apply to embodiments where such a finer level of granularity is used.

According to yet another embodiment, there is provided a hybrid network device, which includes both custom processing circuitry/proprietary OS and COTS processors/standard OS in a network device, e.g. in a card or circuit board within a network device. In certain embodiments of such a hybrid network device, a platform Virtual Machine (VM), such as a VM that implements functionality of a special-purpose network device, could provide for para-virtualization to the hardware present in the hybrid network device.

Fig. 19 is a schematic diagram illustrating an example of how functionality can be distributed or partitioned between different network devices in a general case. In this example, there are at least two individual, but interconnected network devices 300, 310, which may have different functionalities, or parts of the same functionality, partitioned between the network devices 300, 310. There may be additional network device 320 being part of such a distributed implementation. The network devices 300, 310, 320 may be part of the same wireless or wired communication system, or one or more of the network devices may be so-called cloud-based network devices located outside of the wireless or wired communication system.

As used herein, the term “network device” may refer to any device located in connection with a communication network, including but not limited to devices in access networks, core networks and similar network structures. The term network device may also encompass cloud-based network devices.

Hence, yet another aspect of the embodiments relates to a network device comprising a device for managing video segments of a video content according to the invention, such as illustrated in any one of Figs. 13-17.

Fig. 20 is a schematic diagram illustrating an example of a wireless communication system, including a radio access network (RAN) 11 and a core network 12 and optionally an operations and support system (OSS) 13 in cooperation with one or more cloud-based network devices 300. The figure also illustrates a wireless device 15, such as in the form of a user device 15, connected to the RAN 1 1 and capable of conducting wireless communication with a RAN node 10, such as a network node, a base station, node B (NB), evolved node B (eNB), next generation node B (gNB), etc.

The network device 300 illustrated as a cloud-based network device 300 in Fig. 20 may alternatively be implemented in connection with, such as at, the RAN node 10.

In particular, the proposed technology may be applied to specific applications and communication scenarios including providing various services within wireless networks, including so-called Over-the-Top (OTT) services. For example, the proposed technology enables and/or includes transfer and/or transmission and/or reception of relevant user data and/or control data in wireless communications.

In the following, a set of illustrative non-limiting examples will now be described with reference to Figs. 21 to 25. Fig. 21 is a schematic diagram illustrating an example of a wireless network in accordance with some embodiments.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in Fig. 21 . For simplicity, the wireless network of Fig. 21 only depicts network QQ106, network nodes QQ160 and QQ160B, and wireless devices (WDs) QQ1 10, QQ1 10B, and QQ1 10C. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node QQ160 and WD QQ1 10 are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.1 1 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network QQ106 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

Network node QQ160 and WD QQ110 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

As used herein,“network node” refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Yet further examples of network nodes include multi-standard radio (MSR) equipment, such as MSR BSs, network controllers, such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

In Fig. 21 , network node QQ160 includes processing circuitry QQ170, device readable medium QQ180, interface QQ190, auxiliary equipment QQ184, power source QQ186, power circuitry QQ187, and antenna QQ162. Although network node QQ160 illustrated in the example wireless network of Fig. 21 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node QQ160 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium QQ180 may comprise multiple separate hard drives as well as multiple RAM modules). Similarly, network node QQ160 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node QQ160 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeB’s. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node QQ160 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium QQ180 for the different RATs) and some components may be reused (e.g., the same antenna QQ162 may be shared by the RATs). Network node QQ160 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node QQ160, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node QQ160. Processing circuitry QQ170 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry QQ170 may include processing information obtained by processing circuitry QQ170 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Processing circuitry QQ170 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node QQ160 components, such as device readable medium QQ180, network node QQ160 functionality. For example, processing circuitry QQ170 may execute instructions stored in device readable medium QQ180 or in memory within processing circuitry QQ170. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry QQ170 may include a system on a chip (SOC).

In some embodiments, processing circuitry QQ170 may include one or more of radio frequency (RF) transceiver circuitry QQ172 and baseband processing circuitry QQ174. In some embodiments, radio frequency (RF) transceiver circuitry QQ172 and baseband processing circuitry QQ174 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry QQ172 and baseband processing circuitry QQ174 may be on the same chip or set of chips, boards, or units

In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry QQ170 executing instructions stored on device readable medium QQ180 or memory within processing circuitry QQ170. In alternative embodiments, some or all of the functionality may be provided by processing circuitry QQ170 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry QQ170 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry QQ170 alone or to other components of network node QQ160, but are enjoyed by network node QQ160 as a whole, and/or by end users and the wireless network generally.

Device readable medium QQ180 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 00170. Device readable medium QQ180 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry QQ170 and, utilized by network node QQ160. Device readable medium QQ180 may be used to store any calculations made by processing circuitry QQ170 and/or any data received via interface QQ190. In some embodiments, processing circuitry QQ170 and device readable medium QQ180 may be considered to be integrated. Interface QQ190 is used in the wired or wireless communication of signaling and/or data between network node QQ160, network QQ106, and/or WDs QQ110. As illustrated, interface QQ190 comprises port(s)/terminal(s) QQ194 to send and receive data, for example to and from network QQ106 over a wired connection. Interface QQ190 also includes radio front end circuitry QQ192 that may be coupled to, or in certain embodiments a part of, antenna QQ162. Radio front end circuitry QQ192 comprises filters QQ198 and amplifiers QQ196. Radio front end circuitry QQ192 may be connected to antenna QQ162 and processing circuitry QQ170. Radio front end circuitry may be configured to condition signals communicated between antenna QQ162 and processing circuitry QQ170. Radio front end circuitry QQ192 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry QQ192 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters QQ198 and/or amplifiers QQ196. The radio signal may then be transmitted via antenna QQ162. Similarly, when receiving data, antenna QQ162 may collect radio signals which are then converted into digital data by radio front end circuitry QQ192. The digital data may be passed to processing circuitry QQ170. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node QQ160 may not include separate radio front end circuitry QQ192, instead, processing circuitry QQ170 may comprise radio front end circuitry and may be connected to antenna QQ162 without separate radio front end circuitry QQ192. Similarly, in some embodiments, all or some of RF transceiver circuitry QQ172 may be considered a part of interface QQ190. In still other embodiments, interface QQ190 may include one or more ports or terminals QQ194, radio front end circuitry QQ192, and RF transceiver circuitry QQ172, as part of a radio unit (not shown), and interface QQ190 may communicate with baseband processing circuitry QQ174, which is part of a digital unit (not shown).

Antenna QQ162 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna QQ162 may be coupled to radio front end circuitry QQ190 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna QQ162 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as MIMO. In certain embodiments, antenna QQ162 may be separate from network node QQ160 and may be connectable to network node QQ160 through an interface or port. Antenna QQ162, interface QQ190, and/or processing circuitry QQ170 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna QQ162, interface QQ190, and/or processing circuitry QQ170 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry QQ187 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node QQ160 with power for performing the functionality described herein. Power circuitry QQ187 may receive power from power source QQ186. Power source QQ186 and/or power circuitry QQ187 may be configured to provide power to the various components of network node QQ160 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source QQ186 may either be included in, or external to, power circuitry QQ187 and/or network node QQ160. For example, network node QQ160 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry QQ187. As a further example, power source QQ186 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry QQ187. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

Alternative embodiments of network node QQ160 may include additional components beyond those shown in Fig. 21 that may be responsible for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node QQ160 may include user interface equipment to allow input of information into network node QQ160 and to allow output of information from network node QQ160. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node QQ160. As used herein, WD refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop- mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle- mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle- to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (loT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-loT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device QQ1 10 includes antenna QQ1 1 1 , interface QQ1 14, processing circuitry QQ120, device readable medium QQ130, user interface equipment QQ132, auxiliary equipment QQ134, power source QQ136 and power circuitry QQ137. WD QQ110 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD QQ1 10, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD QQ1 10. Antenna QQ1 1 1 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface QQ1 14. In certain alternative embodiments, antenna QQ1 1 1 may be separate from WD QQ1 10 and be connectable to WD QQ1 10 through an interface or port. Antenna QQ1 1 1 , interface QQ1 14, and/or processing circuitry QQ120 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna QQ11 1 may be considered an interface.

As illustrated, interface QQ1 14 comprises radio front end circuitry QQ112 and antenna QQ1 1 1. Radio front end circuitry QQ1 12 comprise one or more filters QQ1 18 and amplifiers QQ116. Radio front end circuitry QQ114 is connected to antenna QQ1 1 1 and processing circuitry QQ120, and is configured to condition signals communicated between antenna QQ1 1 1 and processing circuitry QQ120. Radio front end circuitry QQ1 12 may be coupled to or a part of antenna QQ1 11 . In some embodiments, WD QQ1 10 may not include separate radio front end circuitry QQ112; rather, processing circuitry QQ120 may comprise radio front end circuitry and may be connected to antenna QQ11 1 . Similarly, in some embodiments, some or all of RF transceiver circuitry QQ122 may be considered a part of interface QQ1 14. Radio front end circuitry QQ1 12 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry QQ1 12 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters QQ1 18 and/or amplifiers QQ1 16. The radio signal may then be transmitted via antenna QQ1 1 1 . Similarly, when receiving data, antenna QQ1 1 1 may collect radio signals which are then converted into digital data by radio front end circuitry QQ1 12. The digital data may be passed to processing circuitry QQ120. In other embodiments, the interface may comprise different components and/or different combinations of components. Processing circuitry QQ120 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD QQ1 10 components, such as device readable medium QQ130, WD QQ1 10 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry QQ120 may execute instructions stored in device readable medium QQ130 or in memory within processing circuitry QQ120 to provide the functionality disclosed herein. As illustrated, processing circuitry QQ120 includes one or more of RF transceiver circuitry QQ122, baseband processing circuitry QQ124, and application processing circuitry QQ126. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry QQ120 of WD QQ1 10 may comprise a SOC. In some embodiments, RF transceiver circuitry QQ122, baseband processing circuitry QQ124, and application processing circuitry QQ126 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry QQ124 and application processing circuitry QQ126 may be combined into one chip or set of chips, and RF transceiver circuitry QQ122 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry QQ122 and baseband processing circuitry QQ124 may be on the same chip or set of chips, and application processing circuitry QQ126 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry QQ122, baseband processing circuitry QQ124, and application processing circuitry QQ126 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry QQ122 may be a part of interface QQ1 14. RF transceiver circuitry QQ122 may condition RF signals for processing circuitry QQ120.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry QQ120 executing instructions stored on device readable medium QQ130, which in certain embodiments may be a computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry QQ120 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry QQ120 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry QQ120 alone or to other components of WD QQ1 10, but are enjoyed by WD QQ1 10 as a whole, and/or by end users and the wireless network generally.

Processing circuitry QQ120 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry QQ120, may include processing information obtained by processing circuitry QQ120 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD QQ1 10, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Device readable medium QQ130 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry QQ120. Device readable medium QQ130 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry QQ120. In some embodiments, processing circuitry QQ120 and device readable medium QQ130 may be considered to be integrated.

User interface equipment QQ132 may provide components that allow for a human user to interact with WD QQ1 10. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment QQ132 may be operable to produce output to the user and to allow the user to provide input to WD QQ1 10. The type of interaction may vary depending on the type of user interface equipment QQ132 installed in WD QQ1 10. For example, if WD QQ1 10 is a smart phone, the interaction may be via a touch screen; if WD QQ110 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment QQ132 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment QQ132 is configured to allow input of information into WD QQ1 10, and is connected to processing circuitry QQ120 to allow processing circuitry QQ120 to process the input information. User interface equipment QQ132 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment QQ132 is also configured to allow output of information from WD QQ1 10, and to allow processing circuitry QQ120 to output information from WD QQ1 10. User interface equipment QQ132 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment QQ132, WD QQ110 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein. Auxiliary equipment QQ134 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment QQ134 may vary depending on the embodiment and/or scenario.

Power source QQ136 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD QQ1 10 may further comprise power circuitry QQ137 for delivering power from power source QQ136 to the various parts of WD QQ1 10 which need power from power source QQ136 to carry out any functionality described or indicated herein. Power circuitry QQ137 may in certain embodiments comprise power management circuitry. Power circuitry QQ137 may additionally or alternatively be operable to receive power from an external power source; in which case WD QQ1 10 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry QQ137 may also in certain embodiments be operable to deliver power from an external power source to power source QQ136. This may be, for example, for the charging of power source QQ136. Power circuitry QQ137 may perform any formatting, converting, or other modification to the power from power source QQ136 to make the power suitable for the respective components of WD QQ1 10 to which power is supplied.

Fig. 22 is a schematic diagram illustrating an example of an embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter). UE QQ2200 may be any UE identified by the 3rd Generation Partnership Project (3GPP), including a NB- loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE QQ200, as illustrated in Fig. 22, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable. Accordingly, although Fig. 22 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa. In Fig. 22, UE QQ200 includes processing circuitry QQ201 that is operatively coupled to input/output interface QQ205, radio frequency (RF) interface QQ209, network connection interface QQ21 1 , memory QQ215 including random access memory (RAM) QQ217, read-only memory (ROM) QQ219, and storage medium QQ221 or the like, communication subsystem QQ231 , power source QQ213, and/or any other component, or any combination thereof. Storage medium QQ221 includes operating system QQ223, application program QQ225, and data QQ227. In other embodiments, storage medium QQ221 may include other similar types of information. Certain UEs may utilize all of the components shown in Fig. 22, or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

In Fig. 22, processing circuitry QQ201 may be configured to process computer instructions and data. Processing circuitry QQ201 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry QQ201 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface QQ205 may be configured to provide a communication interface to an input device, output device, or input and output device. UE QQ200 may be configured to use an output device via input/output interface QQ205. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE QQ200. The output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. UE QQ200 may be configured to use an input device via input/output interface QQ205 to allow a user to capture information into UE QQ200. The input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Fig. 22, RF interface QQ209 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface QQ21 1 may be configured to provide a communication interface to network QQ243A. Network QQ243A may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network QQ243A may comprise a Wi-Fi network. Network connection interface QQ21 1 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface QQ21 1 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

RAM QQ217 may be configured to interface via bus QQ202 to processing circuitry QQ201 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM QQ219 may be configured to provide computer instructions or data to processing circuitry QQ201. For example, ROM QQ219 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium QQ221 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium QQ221 may be configured to include operating system QQ223, application program QQ225 such as a web browser application, a widget or gadget engine or another application, and data file QQ227. Storage medium QQ221 may store, for use by UE QQ200, any of a variety of various operating systems or combinations of operating systems.

Storage medium QQ221 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium QQ221 may allow UE QQ200 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium QQ221 , which may comprise a device readable medium. In Fig. 22, processing circuitry QQ201 may be configured to communicate with network QQ243B using communication subsystem QQ231 . Network QQ243A and network QQ243B may be the same network or networks or different network or networks. Communication subsystem QQ231 may be configured to include one or more transceivers used to communicate with network QQ243B. For example, communication subsystem QQ231 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.QQ2, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter QQ233 and/or receiver QQ235 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter QQ233 and receiver QQ235 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem QQ231 may include data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. For example, communication subsystem QQ231 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network QQ243B may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network QQ243B may be a cellular network, a Wi-Fi network, and/or a near-field network. Power source QQ213 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE QQ200. The features, benefits and/or functions described herein may be implemented in one of the components of UE QQ200 or partitioned across multiple components of UE QQ200. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem QQ231 may be configured to include any of the components described herein. Further, processing circuitry QQ201 may be configured to communicate with any of such components over bus QQ202. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry QQ201 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry QQ201 and communication subsystem QQ231 . In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

Fig. 23 is a schematic block diagram illustrating an example of a virtualization environment QQ300 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments QQ300 hosted by one or more of hardware nodes QQ330. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized. The functions may be implemented by one or more applications QQ320 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications QQ320 are run in virtualization environment QQ300 which provides hardware QQ330 comprising processing circuitry QQ360 and memory QQ390. Memory QQ390 contains instructions QQ395 executable by processing circuitry QQ360 whereby application QQ320 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment QQ300, comprises general-purpose or special-purpose network hardware devices QQ330 comprising a set of one or more processors or processing circuitry QQ360, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analogue hardware components or special purpose processors. Each hardware device may comprise memory QQ390-1 which may be non- persistent memory for temporarily storing instructions QQ395 or software executed by processing circuitry QQ360. Each hardware device may comprise one or more network interface controllers (NICs) QQ370, also known as network interface cards, which include physical network interface QQ380. Each hardware device may also include non-transitory, persistent, machine-readable storage media QQ390-2 having stored therein software QQ395 and/or instructions executable by processing circuitry QQ360. Software QQ395 may include any type of software including software for instantiating one or more virtualization layers QQ350 (also referred to as hypervisors), software to execute virtual machines QQ340 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines QQ340, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer QQ350 or hypervisor. Different embodiments of the instance of virtual appliance QQ320 may be implemented on one or more of virtual machines QQ340, and the implementations may be made in different ways.

During operation, processing circuitry QQ360 executes software QQ395 to instantiate the hypervisor or virtualization layer QQ350, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer QQ350 may present a virtual operating platform that appears like networking hardware to virtual machine QQ340.

As shown in Fig. 23, hardware QQ330 may be a standalone network node with generic or specific components. Hardware QQ330 may comprise antenna QQ3225 and may implement some functions via virtualization. Alternatively, hardware QQ330 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) QQ3100, which, among others, oversees lifecycle management of applications QQ320. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, virtual machine QQ340 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of virtual machines QQ340, and that part of hardware QQ330 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines QQ340, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines QQ340 on top of hardware networking infrastructure QQ330 and corresponds to application QQ320 in Fig. 23.

In some embodiments, one or more radio units QQ3200 that each include one or more transmitters QQ3220 and one or more receivers QQ3210 may be coupled to one or more antennas QQ3225. Radio units QQ3200 may communicate directly with hardware nodes QQ330 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.

In some embodiments, some signaling can be effected with the use of control system QQ3230 which may alternatively be used for communication between the hardware nodes QQ330 and radio units QQ3200.

Fig. 24 is a schematic diagram illustrating an example of a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. With reference to Fig. 24, in accordance with an embodiment, a communication system includes telecommunication network QQ410, such as a 3GPP-type cellular network, which comprises access network QQ41 1 , such as a radio access network, and core network QQ414. Access network QQ41 1 comprises a plurality of base stations QQ412a, QQ412b, QQ412c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area QQ413a, QQ413b, QQ413c. Each base station QQ412a, QQ412b, QQ412c is connectable to core network QQ414 over a wired or wireless connection QQ415. A first UE QQ491 located in coverage area QQ413c is configured to wirelessly connect to, or be paged by, the corresponding base station QQ412c. A second UE QQ492 in coverage area QQ413a is wirelessly connectable to the corresponding base station QQ412a. While a plurality of UEs QQ491 , QQ492 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station QQ412.

Telecommunication network QQ410 is itself connected to host computer QQ430, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer QQ430 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections QQ421 and QQ422 between telecommunication network QQ410 and host computer QQ430 may extend directly from core network QQ414 to host computer QQ430 or may go via an optional intermediate network QQ420. Intermediate network QQ420 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network QQ420, if any, may be a backbone network or the Internet; in particular, intermediate network QQ420 may comprise two or more sub-networks (not shown). The communication system of Fig. 24 as a whole enables connectivity between the connected UEs QQ491 , QQ492 and host computer QQ430. The connectivity may be described as an over-the-top (OTT) connection QQ450. Host computer QQ430 and the connected UEs QQ491 , QQ492 are configured to communicate data and/or signaling via OTT connection QQ450, using access network QQ41 1 , core network QQ414, any intermediate network QQ420 and possible further infrastructure (not shown) as intermediaries. OTT connection QQ450 may be transparent in the sense that the participating communication devices through which OTT connection QQ450 passes are unaware of routing of uplink and downlink communications. For example, base station QQ412 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer QQ430 to be forwarded (e.g., handed over) to a connected UE QQ491. Similarly, base station QQ412 need not be aware of the future routing of an outgoing uplink communication originating from the UE QQ491 towards the host computer QQ430.

Fig. 25 is a schematic diagram illustrating an example of a host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Fig. 25. In communication system QQ500, host computer QQ510 comprises hardware QQ515 including communication interface QQ516 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system QQ500. Host computer QQ510 further comprises processing circuitry QQ518, which may have storage and/or processing capabilities. In particular, processing circuitry QQ518 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer QQ510 further comprises software QQ51 1 , which is stored in or accessible by host computer QQ510 and executable by processing circuitry QQ518. Software QQ51 1 includes host application QQ512. Host application QQ512 may be operable to provide a service to a remote user, such as UE QQ530 connecting via OTT connection QQ550 terminating at UE QQ530 and host computer QQ510. In providing the service to the remote user, host application QQ512 may provide user data which is transmitted using OTT connection QQ550.

Communication system QQ500 further includes base station QQ520 provided in a telecommunication system and comprising hardware QQ525 enabling it to communicate with host computer QQ510 and with UE QQ530. Hardware QQ525 may include communication interface QQ526 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system QQ500, as well as radio interface QQ527 for setting up and maintaining at least wireless connection QQ570 with UE QQ530 located in a coverage area (not shown in Fig. 25) served by base station QQ520. Communication interface 00526 may be configured to facilitate connection 00560 to host computer QQ510. Connection QQ560 may be direct or it may pass through a core network (not shown in Fig. 25) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware QQ525 of base station QQ520 further includes processing circuitry QQ528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station QQ520 further has software QQ521 stored internally or accessible via an external connection.

Communication system QQ500 further includes UE QQ530 already referred to. The hardware QQ535 may include radio interface QQ537 configured to set up and maintain wireless connection QQ570 with a base station serving a coverage area in which UE QQ530 is currently located. Hardware QQ535 of UE QQ530 further includes processing circuitry QQ538, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE QQ530 further comprises software QQ531 , which is stored in or accessible by UE QQ530 and executable by processing circuitry QQ538. Software QQ531 includes client application QQ532. Client application QQ532 may be operable to provide a service to a human or non-human user via UE QQ530, with the support of host computer QQ510. In host computer QQ510, an executing host application QQ512 may communicate with the executing client application QQ532 via OTT connection QQ550 terminating at UE QQ530 and host computer QQ510. In providing the service to the user, client application QQ532 may receive request data from host application QQ512 and provide user data in response to the request data. OTT connection QQ550 may transfer both the request data and the user data. Client application QQ532 may interact with the user to generate the user data that it provides.

It is noted that host computer QQ510, base station QQ520 and UE QQ530 illustrated in Fig. 25 may be similar or identical to host computer QQ430, one of base stations QQ412a, QQ412b, QQ412c and one of UEs QQ491 , QQ492 of Fig. 30, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 25 and independently, the surrounding network topology may be that of Fig. 24.

In Fig. 25, OTT connection QQ550 has been drawn abstractly to illustrate the communication between host computer QQ510 and UE QQ530 via base station QQ520, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE QQ530 or from the service provider operating host computer QQ510, or both. While OTT connection QQ550 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

Wireless connection QQ570 between UE QQ530 and base station QQ520 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE QQ530 using OTT connection QQ550, in which wireless connection QQ570 forms the last segment.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection QQ550 between host computer QQ510 and UE QQ530, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection QQ550 may be implemented in software QQ51 1 and hardware QQ515 of host computer QQ510 or in software QQ531 and hardware QQ535 of UE QQ530, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection QQ550 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software QQ51 1 , QQ531 may compute or estimate the monitored quantities. The reconfiguring of OTT connection QQ550 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station QQ520, and it may be unknown or imperceptible to base station QQ520. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer QQ510’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software QQ51 1 and QQ531 causes messages to be transmitted, in particular empty or‘dummy’ messages, using OTT connection QQ550 while it monitors propagation times, errors etc.

Figs. 26 and 27 are schematic flow diagrams illustrating examples of methods implemented in a communication system including, e.g. a host computer, and optionally also a base station and a user equipment in accordance with some embodiments.

Fig. 26 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 21 to 25. For simplicity of the present disclosure, only drawing references to Fig. 26 will be included in this section. In step QQ610, the host computer provides user data. In substep QQ61 1 (which may be optional) of step QQ610, the host computer provides the user data by executing a host application. In step QQ620, the host computer initiates a transmission carrying the user data to the UE. In step QQ630 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step QQ640 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Fig. 27 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 21 to 25. For simplicity of the present disclosure, only drawing references to Fig. 27 will be included in this section. In step QQ710 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step QQ720, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step QQ730 (which may be optional), the UE receives the user data carried in the transmission.

Figs. 28 and 29 are schematic diagrams illustrating examples of methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments.

Fig. 28 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 21 to 25. For simplicity of the present disclosure, only drawing references to Fig. 28 will be included in this section. In step QQ810 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step QQ820, the UE provides user data. In substep QQ821 (which may be optional) of step QQ820, the UE provides the user data by executing a client application. In substep QQ81 1 (which may be optional) of step QQ810, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep QQ830 (which may be optional), transmission of the user data to the host computer. In step QQ840 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Fig. 29 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 21 to 25. For simplicity of the present disclosure, only drawing references to Fig. 29 will be included in this section. In step QQ910 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step QQ920 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step QQ930 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. In the following, examples of illustrative and non-limiting numbered embodiments will be given.

Group A embodiments

1 . A method performed by a wireless device for resolution determination. The method comprising: determining a respective Lagrangian cost for time-aligned video segments from multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory; and

- determining whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

2. The method of embodiment 1 , further comprising:

providing user data; and

- forwarding the user data to a host computer via the transmission to the target network node.

Group B embodiments

3. A method performed by a network node or device for resolution determination. The method comprising:

- determining a respective Lagrangian cost for time-aligned video segments from multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory; and

determining whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

4. The method of embodiment 3, further comprising:

obtaining user data; and

forwarding the user data to a host computer or a wireless device.

Group C embodiments

5. A wireless device comprising processing circuitry configured to perform any of the steps of any of the Group A embodiments. 6. A network node or device, such as a base station, comprising processing circuitry configured to perform any of the steps of any of the Group B embodiments.

7. A user equipment (UE) comprising:

- an antenna configured to send and receive wireless signals;

radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry;

the processing circuitry being configured to perform any of the steps of any of the Group A embodiments;

- an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry;

an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and

a battery connected to the processing circuitry and configured to supply power to the UE.

8. A communication system including a host computer comprising:

processing circuitry configured to provide user data; and

a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE),

- wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments.

9. The communication system of embodiment 8, further including the base station.

10. The communication system of embodiment 8 or 9, further including the UE, wherein the UE is configured to communicate with the base station.

1 1 . The communication system of any one of the embodiments 8 to 10, wherein:

- the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and

the UE comprises processing circuitry configured to execute a client application associated with the host application. 12. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:

at the host computer, providing user data; and

at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the Group B embodiments.

13. The method of embodiment 12, further comprising, at the base station, transmitting the user data. 14. The method of the embodiment 12 or 13, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application.

15. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform any of the steps of any of the Group A embodiments.

16. A communication system including a host computer comprising:

processing circuitry configured to provide user data; and

- a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE),

wherein the UE comprises a radio interface and processing circuitry, the UE’s components configured to perform any of the steps of any of the Group A embodiments. 17. The communication system of embodiment 16, wherein the cellular network further includes a base station configured to communicate with the UE.

18. The communication system of embodiment 16 or 17, wherein:

the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and

the UE’s processing circuitry is configured to execute a client application associated with the host application. 19. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:

at the host computer, providing user data; and

at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the Group A embodiments.

20. The method of embodiment 19, further comprising at the UE, receiving the user data from the base station.

21 . A communication system including a host computer comprising:

communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station,

wherein the UE comprises a radio interface and processing circuitry, the UE’s processing circuitry configured to perform any of the steps of any of the Group A embodiments.

22. The communication system of embodiment 21 , further including the UE.

23. The communication system of embodiment 21 or 22, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.

24. The communication system of any one of the embodiments 21 to 23, wherein:

- the processing circuitry of the host computer is configured to execute a host application; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

25. The communication system of any one of the embodiments 21 to 24, wherein:

- the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and

the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data. 26. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:

at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

27. The method of embodiment 26, further comprising, at the UE, providing the user data to the base station.

28. The method of embodiment 26 or 27, further comprising:

- at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application.

29. The method of any of the embodiments 26 to 28, further comprising:

at the UE, executing a client application; and

- at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application,

wherein the user data to be transmitted is provided by the client application in response to the input data. 30. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments. 31 . The communication system of embodiment 30, further including the base station.

32. The communication system of embodiment 30 or 31 , further including the UE, wherein the UE is configured to communicate with the base station. 33. The communication system of any one of the embodiments 30 to 32, wherein:

the processing circuitry of the host computer is configured to execute a host application;

the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer. 34. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:

at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

35. The method of embodiment 34, further comprising at the base station, receiving the user data from the UE. 36. The method of embodiment 34 or 35, further comprising at the base station, initiating a transmission of the received user data to the host computer.

Group D embodiments

37. A method for determining a resolution for a picture. The method comprising:

38. A device configured to determining a resolution for a picture. The device is configured to

determine a respective Lagrangian cost for time-aligned video segments from multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory; and

determine whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs. 39. A wireless device comprising a device of embodiment 38.

40. A network node comprising a device of embodiment 38.

41 . A network device comprising a device of embodiment 38. 42. A computer program comprising instructions, which when executed by at least one processor, cause the at least one processor to:

determine whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

43. A computer-program product comprising a computer-readable medium having stored thereon a computer program of embodiment 42.

44. An apparatus for determining a resolution for a picture. The apparatus comprises:

- a module for determining a respective Lagrangian cost for time-aligned video segments from multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory; and

a module for determining whether to remove a video segment of the time-aligned video segments from the memory based on the respective Lagrangian costs.

The embodiments described above are to be understood as a few illustrative examples of the invention. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. The scope of the invention is, however, defined by the appended claims.

Claims

1 . A method of managing video segments of a video content, the method comprising:

determining (S1) a respective Lagrangian cost for time-aligned video segments from multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory (102, 121 , 220); and

determining (S2) whether to remove a video segment of the time-aligned video segments from the memory (102, 121 , 220) based on the respective Lagrangian costs.

2. The method according to claim 1 , wherein determining (S1 ) a respective Lagrangian cost comprises determining (S1 ) Jnm - Dnm ⁺ xRnm, wherein Jnm represents Lagrangian cost for video segment number n from representation number m, Dnm represents distortion of video segment number n from representation number m, Rnm denotes bit rate of video segment number n from representation number m and l is a Lagrange multiplier.

3. The method according to claim 1 or 2, wherein determining (S2) whether to remove a video segment comprises determining (S2) whether to remove a video segment of the time-aligned video segments from the memory (102, 121 , 220) based on a comparison of the respective Lagrangian costs.

4. The method according to any one of the claims 1 to 3, wherein determining (S2) whether to remove a video segment comprises identifying a video segment of the time-aligned video segments to remove from the memory (102, 121 , 220) based on the respective Lagrangian costs, the method further comprises removing (S3) the identified video segment from the memory (102, 121 , 220)

5. The method according to claim 4, further comprising updating (S20) a media presentation description comprising information of the multiple representations and the time-aligned video segments by removing information of the removed video segment from the media presentation description.

6. The method according to any one of the claims 1 to 5, further comprising forwarding (S40) the video segments from the memory (102, 121 , 220) to a streaming server (140).

7. The method according to any one of the claims 1 to 6, further comprising streaming (S30) the encoded video content using adaptive bit rate streaming.

8. The method according to any one of the claims 1 to 7, wherein

a first representation of the multiple representations has a lower target bit rate as compared to a second representation of the multiple representations; and

determining (S2) whether to remove a video segment comprises removing (S1 1 ) a video segment from the second representation from the memory (102, 121 , 220) if the Lagrangian cost determined for a video segment from the first representation is lower than the Lagrangian cost determined for the video segment from the second representation.

9. The method according to any one of the claims 1 to 8, wherein

a first representation of the multiple representations has a target lower bit rate as compared to a second representation of the multiple representations; and

determining (S2) whether to remove a video segment comprises removing (S13) a video segment from the first representation from the memory (102, 121 , 220) if:

the Lagrangian cost determined for a video segment from the second representation is equal to or lower than the Lagrangian cost determined for the video segment from the first representation; and

an actual bit rate of the video segment from the second representation is equal to or lower than the target bit rate of the first representation.

10. The method according to any one of the claims 1 to 9, wherein

determining (S2) whether to remove a video segment comprises:

removing (S16) a video segment from the second representation from the memory (102,

121 , 220) if:

the Lagrangian cost determined for a video segment from the first representation is equal to the Lagrangian cost determined for the video segment from the second representation; and an actual bit rate of the video segment from the first representation is lower than an actual bit rate of the video segment from the second representation; and

removing (S17) the video segment from the first representation from the memory (102, 121 ,

220) if:

the Lagrangian cost determined for the video segment from the first representation is equal to the Lagrangian cost determined for the video segment from the second representation; and the actual bit rate of the video segment from the first representation is equal to or higher than the actual bit rate of the video segment from the second representation.

1 1 . The method according to any one of the claims 8 to 10, further comprising updating (S20) a media presentation description comprising information of the multiple representations and the time-aligned video segments by replacing information of the removed video segment from the first representation or from the second representation with information of the video segment from the second representation or from the first representation in the media presentation description.

12. The method according to any one of the claim 8 to 1 1 , further comprising streaming (S30) the encoded video content from the first representation or from the second representation by selecting the video segment from the second representation or from the first representation as a replacement of the removed video segment from the first representation or from the second representation.

13. The method according to any one of the claims 1 to 12, wherein

determining (S1 ) a respective Lagrangian cost comprises determining (S1 ) a respective Lagrangian cost for video segments from least three representations; and

determining (S2) whether to remove a video segment comprises repeating determining (S2) whether to remove a video segment of the time-aligned video segments from the memory (102, 121 , 220) for each pair of representations based on the respective Lagrangian costs determined for the video segments from the pair of representations.

14. A device (100, 1 10, 120, 130) for managing video segments of a video content, the device (100, 1 10, 120, 130) is configured to:

determine a respective Lagrangian cost for time-aligned video segments of multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory (102, 121 ); and

determine whether to remove a video segment of the time-aligned video segments from the memory (102, 121 ) based on the respective Lagrangian costs.

15. The device according to claim 14, wherein the device (100, 1 10, 120, 130) is configured to determine Jnm - Dnm ⁺ xRnm, wherein Jnm represents Lagrangian cost for video segment number n of representation number m, Dnm represents distortion of video segment number n of representation number m, Rnm denotes bit rate of video segment number n of representation number m and l is a Lagrange multiplier.

16. The device according to claim 14 or 15, wherein the device (100, 1 10, 120, 130) is configured to determine whether to remove a video segment of the time-aligned video segments from the memory (102, 121 ) based on a comparison of the respective Lagrangian costs.

17. The device according to any one of the claims 14 to 16, wherein the device (100, 1 10, 120, 130) is configured to:

identify a video segment of the time-aligned video segments to remove from the memory (102, 121 , 220) based on the respective Lagrangian costs; and

remove the identified video segment from the memory (102, 121 , 220).

18. The device according to claim 17, wherein the device (100, 1 10, 120, 130) is configured to update a media presentation description comprising information of the multiple representations and the time- aligned video segments by removing information of the removed video segment from the media presentation description.

19. The device according to any one of the claims 14 to 18, wherein the device (100, 1 10, 120, 130) is configured to forward the video segments from the memory (102, 121 ) to a streaming server (140).

20. The device according to any one of the claims 14 to 19, wherein the device (100, 1 10, 120, 130) is configured to stream the encoded video content using adaptive bit rate streaming.

21 . The device according to any one of the claims 14 to 20, wherein

the device (100, 1 10, 120, 130) is configured to remove a video segment from the second representation from the memory (102, 121 ) if the Lagrangian cost determined for a video segment from the first representation is lower than the Lagrangian cost determined for the video segment from the second representation.

22. The device according to any one of the claims 14 to 21 , wherein

the device (100, 1 10, 120, 130) is configured to remove a video segment from the first representation from the memory (102, 121 ) if:

23. The device according to any one of the claims 14 to 22, wherein

the device (100, 1 10, 120, 130) is configured to:

remove a video segment from the second representation from the memory (102, 121 , 220) if:

remove the video segment from the first representation from the memory (102, 121 , 220) if:

24. The device according to any one of the claims 21 to 23, wherein the device (100, 1 10, 120, 130) is configured to update a media presentation description comprising information of the multiple representations and the time-aligned video segments by replacing information of the removed video segment from the first representation or from the second representation with information of the video segment from the second representation or the first representation in the media presentation description.

25. The device according to any one of the claim 21 to 24, wherein the device (100, 1 10, 120, 130) is configured to stream the encoded video content from the first representation or from the second representation by selecting the video segment from the second representation or from the first representation as a replacement of the removed video segment from the first representation or from the second representation.

26. The device according to any one of the claims 14 to 25, wherein the device (100, 1 10, 120, 130) is configured to:

determine a respective Lagrangian cost for video segments from least three representations; and repeat determining whether to remove a video segment of the time-aligned video segments from the memory (102, 121 ) for each pair of representations based on the respective Lagrangian costs determined for the video segments of the pair of representations.

27. The device according to any one of the claims 14 to 26, further comprising:

a processor (101 ); and

a memory (102) comprising instructions executable by the processor (101 ), wherein the processor (101 ) is operative to

determine the respective Lagrangian cost for time-aligned video segments; and determine whether to remove a video segment of the time-aligned video segments from the memory (102) based on the respective Lagrangian costs.

28. A streaming server (140) comprising a device (100, 1 10, 120, 130) for managing video segments according to any of the claims 14 to 27.

29. A network device (10, 300) comprising a device (100, 1 10, 120, 130) for managing video segments according to any of the claims 14 to 27.

30. A computer program (240) comprising instructions, which when executed by at least one processor (210), cause the at least one processor (210) to:

determine a respective Lagrangian cost for time-aligned video segments of multiple representations, wherein each representation defines a combination of resolution and target bit rate employed to encode the video content according to the representation, and wherein the time-aligned video segments are stored in a memory (220); and determine whether to remove a video segment of the time-aligned video segments from the memory (220) based on the respective Lagrangian costs.

31 . A carrier (250) comprising a computer program (240) according to claim 30, wherein the carrier (250) is one of an electronic signal , an optical signal , an electromagnetic signal , a magnetic signal , an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.