Header compression for optimization

Abstract

Example embodiments of the present disclosure are directed to means for. A method comprises transmitting, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); receiving, from the network entity, information indicative of the header compression applied by the network entity; and applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

Description

HEADER COMPRESSION FOR OPTIMIZATIONFIELD

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for header compression for optimization.BACKGROUND

[0002] A communication network may serve as a facility that enables communications between two or more communication devices or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. A communication device may be provided with a service by an application server.

[0003] The communication network may operate in accordance with standards such as those provided by Third Generation Partnership Project (3GPP) or European Telecommunications Standards Institute (ETSI). Examples of standards provided by 3GPP are the so-called 3GPP standards for cellular technology generations, such as 3GPP standards for 4G technology, 5G technology, 6G technology etc.SUMMARY

[0004] In a first aspect of the present disclosure, there is provided an apparatus. The apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); receive, from the network entity, information indicative of the header compression applied by the network entity; and apply the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

[0005] I n a second aspect of the present disclosure, there is provided a network entity. The network entity comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network entity at least to: receive, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); apply the header compression by the network entity based on the header compression configuration in response to receiving the information; and transmit, to the apparatus, information indicative of the header compression applied by the network entity.

[0006] I n a third aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a network entity, information indicative of a header compression configuration, theheader compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); receiving, from the network entity, information indicative of the header compression applied by the network entity; and applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

[0007] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); applying the header compression by the network entity based on the header compression configuration in response to receiving the information; and transmitting, to the apparatus, information indicative of the header compression applied by the network entity.

[0008] In a fifth aspect of the present disclosure, there is provided an apparatus. The apparatus comprises means for transmitting, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); means for receiving, from the network entity, information indicative of the header compression applied by the network entity; and means for applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

[0009] In a sixth aspect of the present disclosure, there is provided a network entity. The network entity comprises means for receiving, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); means for applying the header compression by the network entity based on the header compression configuration in response to receiving the information; and means for transmitting, to the apparatus, information indicative of the header compression applied by the network entity.

[0010] In aseventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

[0011] In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

[0012] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensiblethrough the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0014] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0015] FIG. 2 illustrates an example signaling process in accordance with some embodiments in the disclosure;

[0016] FIG. 3 illustrates an example signaling process in accordance with some embodiments in the disclosure;

[0017] FIG. 4 illustrates an example signaling process in accordance with some embodiments in the disclosure;

[0018] FIG. 5 illustrates an example signaling process in accordance with some embodiments in the disclosure;

[0019] FIG. 6 illustrates a flowchart of a method implemented at an apparatus in accordance with some example embodiments of the present disclosure;

[0020] FIG. 7 illustrates a flowchart of a method implemented at a network entity in accordance with some example embodiments of the present disclosure;

[0021] FIG. 8 illustrates a flowchart of a method implemented at an apparatus in accordance with some example embodiments of the present disclosure;

[0022] FIG. 9 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0023] FIG. 10 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0024] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0025] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0026] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in theart to which this disclosure belongs.

[0027] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0028] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0029] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0030] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0032] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0033] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0034] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-loT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), 5.5G, the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0035] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (I AB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-groundnetwork device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0036] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0037] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0038] FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100,a plurality of communication devices, including a terminal device 110, a network device 120 and a network entity 130, can communicate with each other. In the example of FIG. 1, the terminal device 110 may be a UE, the network device 120 may be a base station serving the UE and the network entity 130 may be one or more functions of the core network. The serving area of the network device 120 may be called a cell.

[0039] It is to be understood that the number of devices and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of devices configured to implementing example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell, and one or more additional cells may be deployed in the communication environment 100. It is noted that although illustrated as a network device, the network device 120 may be another device than a network device. Although illustrated as a terminal device, the terminal device 110 may be another device than a terminal device.

[0040] In the following, for the purpose of illustration, some example embodiments are described with the terminal device 110 operating as a UE in non-terrestrial networks (NTNs), the network device 120 operating as a satellite or server device in NTNs and the network entity 130 operating as a packet data network gateway (PGW). However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other devices. In NTNs, the network device 120 may be a base station (an eNode B or gNode B) that is deployed at the satellite or a base station that is at a ground connected with a satellite via gateway.

[0041] In some example embodiments, a transmission direction from the network device 120 to the terminal device 110 is referred to as a downlink (DL), while a transmission direction from the terminal device 110 to the network device 120 is referred to as an uplink (UL). In DL, the network device 120 is a transmitting (TX) device (or a transmitter) and the terminal device 110 is a receiving (RX) device (or a receiver). In UL, the terminal device 110 is a TX device (or a transmitter) and the network device 120 is a RX device (or a receiver).

[0042] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division MultipleAccess (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0043] Non-terrestrial networks (NTNs) include wireless communication systems providing nonterrestrial wireless access to UEs by means of an NTN payload integrated either in airborne platforms (for example, high-altitude platforms (HAPs)) or space-borne NTN vehicles (for example, satellites), and an NTN-gateway (NTN Gateway (NTN-GW)). The NTN vehicle operates above Earth’s surface, using platforms in the air in Earth’s orbit. These platforms may include satellites in a low Earth orbit (LEO), medium Earth orbit (MEO), and geostationary orbit (GEO), HEO (highly elliptical orbit) as well as HAPs and drones. An orbit of a satellite can be a geosynchronous orbit (GSO) or non-geosynchronous orbit (NGSO).

[0044] GEOs, also referred to as a geosynchronous equatorial orbits, are circular orbits 35,786 km above Earth’s equator and follow the direction of Earth's rotation. GEO satellites appear stationary relative to a fixed point on Earth but still have slight orbital movement.

[0045] GSOs are a circular orbit about 35,786 kilometers above the Earth’s surface. At any inclination, a geosynchronous orbit synchronizes with the rotation of the Earth. More specifically, the time it takes for the Earth to rotate on its axis is 23 hours, 56 minutes, and 4.09 seconds, which is the same as a satellite in a geosynchronous orbit. The GSO can have any inclination, so the key difference with GEOs is the fact that GEOs always lie on the same plane as the equator of Earth.

[0046] Internet protocol (IP) multimedia subsystem (IMS) is a service framework for delivering multimedia services, such as voice, video and text messaging over IP networks. There are ongoing discussions on the support for IMS voice communications transmitted via narrowband Internet of things (NB-loT) over NTNs, especially GEO satellites. IMS voice communication consists of two types of data traffic: a) IMS signaling with quality of service (QoS) class identifier (QCI) 1 and b) voice data packets with QCI 5.

[0047] One option to realize IMS voice communications over NTNs is via the user plane cellular Internet of things (C-loT) optimization procedure. A UE with a packet data network (PDN) connection to an IMS network for voice services, e.g., voice over LTE (VoLTE), may have: i) guaranteed bit rate (GBR) bearer 1 for voice calls with a specific GBR and QCI value (e.g., QC1 1 for conversational voice), ii) non-GBR bearer for signaling and other best-effort data traffic with a different QCI value (e.g., QCI 5 for IMS signaling). Another option to realize IMS voice communication is via control plane optimization procedure.

[0048] The user plane C-loT evolved packet system (EPS) optimization functionality enables thesupport for transfer of user plane data without the need for using the service request procedure to establish access stratum (AS) context in a serving node and UE. loT devices may utilize user plane C-loT optimization for IMS voice communication over NTNs. Header compression e.g. via robust header compression (ROCH), is a mechanism to reduce the overhead of protocol headers, which is currently performed at the AS, e.g., the packet data convergence protocol (PDCP) layer at the UE and radio access network for data sent via user plane optimization, or at the non-access stratum (NAS) layer (RAN) layer at the UE and a mobility management entity (MME) for data sent via control plane optimization in 4G LTE (or access and mobility management function (AMF) in 5G NR). However, commercially available loT devices may not support header compression at the PDCP layer. Further, for IMS calls via NB-loT over NTNs, respective data is transmitted between the UE and the packet data network gateway (PGW), and the PGW does not use PDCP or NAS layer.

[0049] This disclosure aims to address at least one of the above problems. A solution is provided to support header compression for the loT devices that do not support header compression at the AS, e.g., the PDCP layer. Further, a solution to support header compression for NTN wireless interfaces (e.g., service link and feeder link) is also provided, which is important for NTN GEO satellites where the throughput is even limited for the regenerative architecture due to their distances to the Earth.

[0050] The primary principle in the disclosure is to enable the header compression at an upper layer (e.g., the application layer) without relying on AS or NAS compression. In other words, the compression is done at the upper layer in the UE and the core network.

[0051] Referring now to FIG. 2, which illustrates an example signaling process 200 in accordance with some embodiments in the disclosure. The example signaling process 200 is between a UE 210 and a network entity 130. The UE 210 may be an loT device and the network entity 130 may be a network function in the core network, e.g., the PGW in 4G LTE or the user plane function (UPF) in 5G NR.

[0052] The UE 210 transmits to the network entity 130, information indicative of a header compression configuration 201 , the configuration indicating a header compression for data transmitted at a layer above access stratum (AS). The information may be transmitted to the network entity 130 via a network device (not shown in FIG. 2).

[0053] In some example embodiments, the AS (or AS layers) may include radio-related functions and signaling between the UE 210 and the network device (e.g., base station, eNode B or gNode B). Examples of access stratum protocols may be media access control (MAC), radio link control (RLC), radio resource control (RRC), PDCP, or service data adaptation protocol (SDAP).

[0054] The UE 210 receives from the network entity 130 information 202 indicative of the header compression applied at the network entity 130. The information indicative of the header compressionapplied by the network entity 130 may be transmitted via an explicit or implicit confirmation 202 indicating the application of the header compression by the network entity 130.

[0055] The UE 210 applies 203 the header compression based on the header compression configuration and the information indicative of the header compression applied by the network entity 130. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of compressing the headers of data transmitted via the user plane for optimization.

[0056] In some example embodiments, the UE 210 may then start to transmit data with compressed headers 204 to the network entity 130. The header compression for the data is performed at the UE 210 in accordance with the configuration at the layer above the AS. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of transmitting data with corresponding headers compressed via the user plane for optimization.

[0057] In some example embodiments, the UE 210 may also receive data 205 with headers compressed in accordance with the configuration at the layer above the AS from the network entity 130. The UE 210 may then perform header decompression 206 on the received data in accordance with the configuration. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for network entities with no AS and without providing header compression at the AS, header compression at a layer above the AS provides these network entities the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0058] In some example embodiments, the configuration may further indicate that the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane. The data here may be user data, e.g., voice data, video data, etc. In some example embodiments, the NAS (or NAS layer) may include functions and signaling between the UE 210 and the core network for the mobility control and session management of the UE 210. For instance, these functions and signaling may involve session management, mobility management and connection management. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0059] In some example embodiments, the UE 210 may transmit to the network entity 130, data via the control plane with headers compressed in accordance with the configuration at the layer abovethe NAS. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for network entities with no NAS and without providing header compression at the NAS, header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0060] In some example embodiments, the UE 210 may receive from the network entity 130, data via the control plane with headers compressed in accordance with the configuration at the layer above the NAS and perform header decompression on the received data in accordance with the configuration. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for network entities with no NAS and without providing header compression at the NAS, header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted over the control plane for optimization.

[0061] In some example embodiments, the layer above the AS, or the layer above the NAS include at least one of: a network layer, a transport layer or an application layer.

[0062] In some example embodiments, the configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification. The dynamic update of the header compression configuration provides flexibility.

[0063] Referring now to FIG. 3, which illustrates an example signaling process 300 in accordance with some embodiments in the disclosure. The example signaling process 200 is between the UE 210 and the network entity 130. The UE 210 may be an loT device and the network entity 130 may be a network function in the core network, e.g., the PGW in 4G LTE or the user plane function (UPF) in 5G NR.

[0064] The UE 210 receives a request 301 (e.g., from a user of the UE 210) for initiating a voice communication over a non-terrestrial network (NTN).

[0065] The UE 210 transmits a request 302 to the network entity 130 for establishing a packet data network (PDN) connection over the NTN, in response to receiving the request for initiating the voice communication. The request for establishing the PDN connection comprises information indicative of a header compression configuration and the header compression configuration indicates a header compression for voice data transmitted at a layer above access stratum (AS). The information may be transmitted to the network entity 130 via a network device (not shown in FIG. 3).

[0066] In some example embodiments, the AS or AS layers may include radio-related functions and signaling between the UE 210 and a base station (e.g., an eNode B or gNode B). Examples of access stratum protocols may be media access control (MAC), radio link control (RLC), radio resource control(RRC), PDCP, or service data adaptation protocol (SDAP).

[0067] The UE 210 receives from the network entity 130 information 303 indicative of the header compression applied at the network entity 130. The information indicative of the header compression applied by the network entity 130 may be transmitted via an explicit or implicit confirmation 303 indicating the application of the header compression by the network entity 130.

[0068] The UE 210 applies 304 the header compression based on the header compression configuration and the information indicative of the header compression applied by the network entity 130. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of compressing the headers of voice data transmitted via the user plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is very limited.

[0069] In some example embodiments, the UE 210 may then start to transmit voice data with compressed headers 305 to the network entity 130. The header compression for the data is performed at the UE 210 in accordance with the configuration at the layer above the AS. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of transmitting voice data with corresponding headers compressed via the user plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is very limited.

[0070] In some example embodiments, the UE 210 may also start to receive voice data 306 with headers compressed in accordance with the configuration at the layer above the AS from the network entity 130. The UE 210 may then perform header decompression 206 on the received voice data in accordance with the configuration. For network entities with no AS and without providing header compression at the AS, header compression at a layer above the AS provides these network entities the ability of (de)compressing the headers of voice data transmitted via the user plane for optimization.

[0071] In some example embodiments, the configuration may further indicate that the header compression performed at a layer above non-access stratum (NAS) for voice data transmitted via a control plane. The NAS or NAS layer may include functions and signaling between the UE 210 and the core network for the mobility control and session management of the UE 210. For instance, these functions and signaling may involve session management, mobility management and connection management. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0072] In some example embodiments, the UE 210 may transmit to the network entity 130, data via the control plane with headers compressed in accordance with the configuration at the layer above the NAS. For network entities with no NAS and without providing header compression at the NAS,header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0073] In some example embodiments, the UE 210 may receive from the network entity 130, data via the control plane with headers compressed in accordance with the configuration at the layer above the NAS and perform header decompression on the received data in accordance with the configuration. For network entities with no NAS and without providing header compression at the NAS, header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted over the control plane for optimization.

[0074] In some example embodiments, the layer above the AS, or the layer above the NAS include at least one of: a network layer, a transport layer or an application layer.

[0075] In some example embodiments, the configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification. The dynamic update of the header compression configuration provides flexibility.

[0076] Referring now to FIG. 4, which illustrates an example signaling process 400 in accordance with some embodiments in the disclosure. The example signaling process 400 illustrates an overall process in which enhancements at the attach request procedure enabling header compression to take place at a layer above PDCP layer and corresponding header decompression to take place at a PGW of the core network for uplink data packets, and vice versa for downlink data packets. For the purpose of illustration, user plane optimization is utilized in the example signaling process 400. Control plane optimization may follow a similar process with data transmitted via the control plane and header compression performed at a layer above the NAS. It should be noted that though in FIG. 4 the example signaling process 400 is illustrated and described with 4G LTE as an example, it may also be applied to the 5G and 6G, or possible future architectures with adaptations to respective architectures. For example, the eNode B 220 may be the gNode B, the PGW may be the user plane function (UPF) and the MME may be the access and mobility management function (AMF) for 5G NR.

[0077] The UE 210 may initiate an attach request 401 to the eNB 220. The UE 210 may indicate its support for user plane C-loT EPS optimization in the attach request. The UE 210 transmits in the attach request 401 information indicative of a header compression configuration indicating that the header compression for data is to be performed at a layer above the AS, e.g., at the network layer, the transport later, or the application layer. The header compression configuration may include the information necessary for a robust header compression (ROHC) channel setup, e.g., at least one ROHC profile, and a ROHC configuration including ROHC channel parameters, header compression feedback mechanism, ROHC context initialization parameters, ROHC packet formats, or ROHC negotiation parameters, etc.

[0078] The following process follows current standards until the create session request 412, 413. The eNode B 220 may forward 402 the attach request to an MME 131 -1. If the MME 131 -1 the UE 210 is connecting is different from the one it used before detaching (a new one), the new MME 131 -1 may send an identification request 403 to an old (previous) MME or serving GPRS support node (SGSN) 131-2 to verify the identity of the UE 210 with an equipment identity register (EIR) 131-3. The old MME / SGSN 131-2 may respond with an identification response 403. The new MME 131-1 may initiate authentication by sending an identity request 404 to the UE 210. The UE 210 may respond with an identity response 404. The new MME 131-1 may perform authentication and security procedures 405a to verify the legitimacy of the UE 210. The new MME 131 -1 may also perform a mobile equipment (ME) identity check 405b if needed. If additional security parameters are needed, the new MME 131-1 may exchange ciphered options request and response 406 with the UE 210.

[0079] If the UE 210 was previously connected to the old MME / SGSN 131-2, the new MME 131-1 may initiate a delete session request 407 to a serving GW (S-GW) 132 and PGW (P-GW) 133 to remove old session data. The PGW 133 may confirm session termination through a policy and charging enforcement function (PCEF 134)-initiated IP connectivity access network (IP-CAN) session termination process 407. Similarly, the old MME / SGSN 131-2 may also initiate a delete session request 410 to the old serving GW (S-GW) 132 and PGW (P-GW) 133 to remove old session data. The PGW 133 may confirm session termination through a policy and charging enforcement function (PCEF 134)-initiated IP connectivity access network (IP-CAN) session termination process 410. The new MME 131 -1 may update the location of the UE 210 by sending an update location request 408 to a home subscriber server (HSS) 135. The HSS 135 may transmit a cancel location request 409 to the old MME / SGSN 131-2, which responds with a cancel location acknowledgement 409. The HSS 135 may process the location update and respond with an update location acknowledgement 411 to the new MME 131-1.

[0080] If the MME determines that the PDN connection would use user plane C-loT EPS optimization and the UE 210 supports header compression at an upper layer above the AS, e.g., the PDCP layer, the new MME 131-1 may include the header compression configuration in the create session request 412, 413 transmitted to the serving GW 132 and the PGW 133.

[0081] If the user plane C-loT EPS optimization applies, the PGW 133 may confirm via the serving GW 132, its support for the header compression configuration indicated by the UE 210. If the user plane C-loT EPS optimization applies to an IP PDN connection, and the UE 210 has transmitted in the attach request the header compression configuration, the PGW 133 then returns a PDN connectivity accept in a create session response 415 to the serving GW 132 which returns a create session response 416 including a confirmation of the application of the header compressionconfiguration 414. The PGW 133 may parallelly apply the header compression configuration by binding the uplink and downlink ROHC channels to support header compression feedback signaling. The new MME 131 -1 may optionally indicate to the eNode B 220 to not apply any AS layer header compression (e.g., PDCP layer) and notify the UE 210 the confirmation of the application of the header compression at the layer above the AS. If the UE 210 has transmitted in the attach request the header compression context setup parameters in the header compression configuration, the PGW 133 may acknowledge the header compression context setup parameters. If, however the ROHC context is not established during the attach procedure for the PDN connection, then before transmitting data with the compressed format, the UE 210 and the PGW 133 may need to establish the ROHC context with ROHC initialization and refresh (IR) packet based on the header compression configuration.

[0082] The new MME 131-1 may then initiate 417 an initial context setup request or downlink NAS transport with attach accept. The RRC connection reconfiguration or RRC direct transfer 418 may be triggered. In response to a completion of RRC connection reconfiguration followed by an initial context setup response 420, or a direct transfer 421 , the UE 210 may transmit an attach complete 422 to the new MME 131-1 to confirm the completion of the attach procedure.

[0083] The bearer settings may be updated via modify bearer request 423, 423a and corresponding modify bearer response 424, 424a and the bearer setting updates may be notified 425, 426 to relevant parties. The UE 210, with the configuration where the header compression performed at a layer above the AS enabled, starts to transmit uplink data with headers compressed at the layer above the AS to the PGW 133 via the eNode B 220. The PGW 133 receiving the data with headers compressed at the layer above the AS may then perform header decompression on the received data in accordance with the header compression configuration. Similarly, the PGW 133 may transmit downlink data with headers compressed at the layer above the AS to the UE 210 via the eNode B 220. The UE 210 receiving the data with headers compressed at the layer above the AS may then perform header decompression on the received data in accordance with the header compression configuration.

[0084] Referring now to FIG. 5, which illustrates an example signaling process 500 in accordance with some embodiments in the disclosure. The example signaling process 500 illustrates an overall process in which enhancements at a PDN connectivity procedure enabling header compression to take place at a layer above PDCP layer and corresponding header decompression to take place at a PDN gateway of the core network for uplink data packets, and vice versa for downlink data packets. User plane optimization is utilized in the example signaling process 500. Control plane optimization may follow a similar process with data transmitted via the control plane and header compression performed at a layer above the NAS. It should be noted that though in FIG. 4 the example signaling process 400 is illustrated and described with 4G LTE as an example, it may also be applied to the 5Gand 6G, or possible future architectures with adaptations to respective architectures. For example, the eNode B 220 may be the gNode B, the PGW may be the user plane function (UPF), and the MME may be the access and mobility management function (AMF) for 5G NR.

[0085] The UE 210 may initiate a PDN connectivity request 501 to the MME 131-1. The UE 210 may indicate its support for user plane C-loT EPS optimization in the PDN connectivity request. The UE 210 transmits in the PDN connectivity request 501 information indicative of a header compression configuration indicating that the header compression for data is to be performed at a layer above the AS, e.g., at the network layer, the transport layer, or the application layer. The header compression configuration may include the information necessary for the ROHC channel setup, e.g., at least one ROHC profile and a ROHC configuration including ROHC channel parameters, header compression feedback mechanism, ROHC context initialization parameters, ROHC packet formats, or ROHC negotiation parameters, etc.

[0086] If the MME 131-1 determines that the PDN connection would use user plane C-loT EPS optimization and the UE 210 supports header compression at an upper layer above the AS, e.g., the PDCP layer, the MME 131-1 may include the header compression configuration in the create session request 512, 513 transmitted to the serving GW 132 and the PGW 133.

[0087] If the user plane C-loT EPS optimization applies, the PGW 133 may confirm via the serving GW 132, its support for the header compression configuration indicated by the UE 210. The PGW 133 then returns a PDN connectivity accept in the create session response 505 to the serving GW 132 which returns the create session response 506 including the confirmation of the application of the header compression configuration 514. The PGW 133 may parallelly apply the header compression configuration by binding the uplink and downlink ROHC channels to support header compression feedback signaling. If the UE 210 has transmitted in the PDN connectivity request the header compression context setup parameters in the header compression configuration, the PGW 133 may acknowledge the header compression context setup parameters. The MME 131-1 may optionally indicate to the eNode B 220 to not apply any AS layer header compression (e.g., PDCP layer) and notify the UE 210 the confirmation of the application of the header compression at the layer above the AS. If, however the ROHC context is not established during the attach procedure for the PDN connection, then before transmitting data with the compressed format, the UE 210 and the PGW 133 may need to establish the ROHC context with ROHC initialization and refresh (IR) packet based on the header compression configuration.

[0088] The MME 131-1 may then initiate 507 initial bearer setup request or downlink NAS transport with PDN connectivity. The RRC connection reconfiguration or RRC direct transfer 508 may be triggered. In response to a completion of RRC connection reconfiguration 509 followed by bearersetup response 510, or a direct transfer 511, the UE 210 may transmit a PDN connectivity complete 512 to the MME 131-1 to confirm the completion of the PDN connectivity procedure.

[0089] The bearer settings may be updated via modify bearer request 513, 513a and corresponding modify bearer response 514, 514a and the bearer setting updates may be notified 515, 516 to relevant parties. The UE 210, with the configuration where the header compression performed at a layer above the AS enabled, starts to transmit uplink data with headers compressed at the layer above the AS to the PGW 133 via the eNode B 220. The PGW 133 receiving the data with headers compressed at the layer above the AS may then perform header decompression on the received data in accordance with the header compression configuration. Similarly, the PGW 133 may transmit downlink data with headers compressed at the layer above the AS to the UE 210 via the eNode B 220. The UE 210 receiving the data with headers compressed at the layer above the AS may then perform header decompression on the received data in accordance with the header compression configuration.

[0090] It should be noted, although example embodiments are discussed with user plane C-loT optimization in 4G LTE architecture in the above, embodiments using user plane optimization in 5G NR (or future architectures), or control plane C-loT optimization in 4G LTE and 5G NR (or future architectures) would also fall into the scope of the disclosure. For example, for 5G NR, the header compression above the AS may be, e.g., above the SDAP layer.

[0091] With any of above discussed embodiments, the support for header compression for loT devices not supporting header compression at the AS, e.g., the PDCP layer, or for the scenarios where data is transferred between a UE and a network entity with no PDCP or NAS layer in presence. In the context of voice communication over NTNs, header compression for voice data transmitted via user plane optimization is enabled, which is important as the throughput is very limited and header compression reduces overall overhead.

[0092] FIG. 6 shows a flowchart of an example method 600 implemented at an apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the terminal device 110 in FIG. 1.

[0093] At block 610, transmitting, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS).

[0094] At block 620, receiving, from the network entity, information indicative of the header compression applied by the network entity.

[0095] At block 630, applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity. Header compression at a layer above the AS provides the ability of (de)compressingthe headers of data transmitted over the user plane. Further, for loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0096] In some example embodiments, the method 600 further comprises: transmitting to the network entity via a network device, data with header compressed in accordance with the header compression configuration at the layer above the AS. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0097] In some example embodiments, the method 600 further comprises: receiving from the network entity via the network device, data with headers compressed in accordance with the header compression configuration at the layer above the AS; and performing header decompression on the received data in accordance with the header compression configuration. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0098] In some example embodiments, the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for loT devices that do not support header compression at the NAS, header compression at a layer above the NAS provides for these loT devices, the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0099] In some example embodiments, the method 600 further comprises: transmitting to the network entity via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for loT devices that do not support header compression at the NAS, header compression at a layer above the NAS provides for these loT devices, the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0100] In some example embodiments, the method 600 further comprises: receiving from the network entity via the network device, data via the control plane with headers compressed inaccordance with the header compression configuration at the layer above the NAS; and performing header decompression on the received data in accordance with the header compression configuration. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for loT devices that do not support header compression at the NAS, header compression at a layer above the NAS provides for these loT devices, the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0101] In some example embodiments, the method 600 further comprises: transmitting to the network entity via the network device, capability information indicating a support for at least one of: the header compression for data at the layer above the AS, or the header compression for data transmitted via the control plane at the layer above the NAS. The capability information enables the network to be aware of the capability of the apparatus in terms of its support for header compression at a layer above the AS or the NAS.

[0102] In some example embodiments, the header compression configuration comprises at least one of: at least one robust header compression (ROHC) configuration, or at least one RHOC profile. The inclusion of header compression configuration enables the apparatus and the network entity to apply corresponding configurations for header compression.

[0103] In some example embodiments, the information indicative of the header compression configuration is transmitted in one of: a non-access stratum (NAS) attach request, or a request for establishing a packet data network (PDN) connection. The different transmission methods for the header compression configuration enable the apparatus and network entity to initiate the header compression at different stages.

[0104] In some example embodiments, the layer above the AS or above the NAS comprises at least one of: a network layer, a transport layer, or an application layer. The different layers provide different options for header compression at an upper layer.

[0105] In some example embodiments, the header compression configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification. The dynamic update of the header compression configuration provides flexibility.

[0106] FIG. 7 shows a flowchart of an example method 700 implemented at a network entity in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the network entity 130 in FIG. 1.

[0107] At block 710, receiving, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS).

[0108] At block 720, applying the header compression by the network entity based on the headercompression configuration in response to receiving the information.

[0109] At block 730, transmitting, to the apparatus, information indicative of the header compression applied by the network entity. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for network entities with no AS and without providing header compression at the AS, header compression at a layer above the AS provides these network entities the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0110] In some example embodiments, the method 700 further comprises: receiving from the apparatus via a network device, data with headers compressed in accordance with the header compression configuration at the layer above the AS. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for network entities with no AS and without providing header compression at the AS, header compression at a layer above the AS provides these network entities the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0111] In some example embodiments, the method 700 further comprises: performing header compression for data in accordance with the header compression configuration at the layer above the AS; and transmitting to the apparatus via the network device, the data with compressed headers. Header compression at a layer above the AS provides the ability of (de)compressing the headers of data transmitted over the user plane. Further, for network entities with no AS and without providing header compression at the AS, header compression at a layer above the AS provides these network entities the ability of (de)compressing the headers of data transmitted via the user plane for optimization.

[0112] In some example embodiments, the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane. The data here may be user data, e.g., voice data, video data, etc. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for network entities with no NAS and without providing header compression at the NAS, header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0113] In some example embodiments, the method 700 further comprises: receiving from the apparatus via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for network entities with no NAS and without providing header compression at the NAS,header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0114] In some example embodiments, the method 700 further comprises: performing header compression for data in accordance with the header compression configuration at the layer above the NAS; and transmitting to the apparatus via the network device, data with compressed headers via the control plane. Header compression at a layer above the NAS provides the ability of (de)compressing the headers of data transmitted over the control plane. Further, for network entities with no NAS and without providing header compression at the NAS, header compression at a layer above the NAS provides these network entities the ability of (de)compressing the headers of data transmitted via the control plane for optimization.

[0115] In some example embodiments, the method 700 further comprises: receiving from the apparatus via the network device, capability information indicating a support for at least one of: the header compression for data at the layer above the AS, or the header compression for data transmitted via the control plane at the layer above the NAS. The capability information enables the network to be aware of the capability of the apparatus in terms of its support for header compression at a layer above the AS or the NAS.

[0116] In some example embodiments, the header compression configuration comprises at least one of: at least one robust header compression (ROHC) configuration, or at least one RHOC profile. The inclusion of header compression configuration enables the apparatus and the network entity to apply corresponding configurations for header compression.

[0117] In some example embodiments, the information indicative of the header compression configuration is transmitted in one of: a non-access stratum (NAS) attach request, or a request for establishing a packet data network (PDN) connection. The different transmission methods for the header compression configuration enable the apparatus and network entity to initiate the header compression at different stages.

[0118] In some example embodiments, the layer above the AS or above the NAS comprises at least one of: a network layer, a transport layer, or an application layer. The different layers provide different options for header compression at an upper layer.

[0119] In some example embodiments, the network entity is a packet data network gateway (PGW). This enables the implementations in 4G architecture.

[0120] In some example embodiments, the header compression configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification. The dynamic update of the header compression configuration provides flexibility.

[0121] FIG. 8 shows a flowchart of an example method 800 implemented at an apparatus inaccordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the terminal device 110 in FIG. 1.

[0122] At block 810, receiving a request for initiating a voice communication over a non-terrestrial network (NTN).

[0123] At block 820, transmitting, to a network entity via a network device, a request for establishing a packet data network (PDN) connection over the NTN in response to receiving the request for initiating the voice communication, the request for establishing the PDN connection comprising information indicative of a header compression configuration and the header compression configuration indicating the header compression for voice data transmitted at a layer above access stratum (AS).

[0124] At block 830, receiving, from the network entity via the network device, information indicative of the header compression applied by the network entity.

[0125] At block 840, applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of (de)compressing the headers of voice data transmitted via the user plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is very limited.

[0126] In some example embodiments, the method 800 further comprises: transmitting to the network entity via the network device, voice data with headers compressed by the apparatus in accordance with the header compression configuration at the layer above the AS. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of (de)compressing the headers of voice data transmitted via the user plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is very limited.

[0127] In some example embodiments, the method 800 further comprises: receiving from the network entity via the network device, voice data with headers compressed by the network entity in accordance with the header compression configuration at the layer above the AS; and performing header decompression on the received voice data in accordance with the header compression configuration. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the AS provides for these loT devices, the ability of (de)compressing the headers of voice data transmitted via the user plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is verylimited.

[0128] In some example embodiments, the method 800 further comprises: transmitting to the network entity via the network device, capability information indicating a support for the header compression for voice data at the layer above the AS. The capability information enables the network to be aware of the capability of the apparatus in terms of its support for header compression at a layer above the AS.

[0129] In some example embodiments, the header compression configuration comprises at least one of: at least one robust header compression (ROHC) configuration, or at least one RHOC profile. The inclusion of header compression configuration enables the apparatus and the network entity to apply corresponding configurations for header compression.

[0130] In some example embodiments, the voice communication over the NTN utilizes user plane optimization. This enables the application of header compression at a layer above the AS to the NTN user plane optimization.

[0131] In some example embodiments, the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the NAS provides for these loT devices, the ability of (de)compressing the headers of voice data transmitted via the control plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is very limited.

[0132] In some example embodiments, the method 800 further comprises: transmitting to the network entity via the network device, data via the control plane with headers compressed by the apparatus in accordance with the header compression configuration at the layer above the NAS. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the NAS provides for these loT devices, the ability of (de)compressing the headers of voice data transmitted via the control plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is very limited.

[0133] In some example embodiments, the method 800 further comprises: receiving from the network entity via the network device, data via the control plane with headers compressed by a network entity in accordance with the header compression configuration at the layer above the NAS; and performing header decompression on the received data in accordance with the header compression configuration. For loT devices that do not support header compression at the AS (e.g., PDCP layer), header compression at a layer above the NAS provides for these loT devices, the ability of (de)compressing the headers of voice data transmitted via the control plane for optimization. This is important in the context of voice communication over GEO satellites where the throughput is verylimited.

[0134] In some example embodiments, the method 800 further comprises: transmitting to the network entity via the network device, capability information indicating a support for the header compression at the layer above the NAS for data transmitted via the control plane. The capability information enables the network to be aware of the capability of the apparatus in terms of its support for header compression at a layer above the NAS.

[0135] In some example embodiments, the voice communication overthe NTN utilizes control plane optimization. This enables the application of header compression at a layer above the NAS to the NTN control plane optimization.

[0136] In some example embodiments, the layer above the AS or above the NAS comprises at least one of: a network layer, a transport layer, or an application layer. The different layers provide different options for header compression at an upper layer.

[0137] In some example embodiments, the header compression configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification. The dynamic update of the header compression configuration provides flexibility.

[0138] In some example embodiments, an apparatus capable of performing any of the method 600 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0139] In some example embodiments, the apparatus comprises means for transmitting, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); means for receiving, from the network entity, information indicative of the header compression applied by the network entity; and means for applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

[0140] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via a network device, data with header compressed in accordance with the header compression configuration at the layer above the AS.

[0141] In some example embodiments, the apparatus further comprises: means for receiving from the network entity via the network device, data with headers compressed in accordance with the header compression configuration at the layer above the AS; and means for performing header decompression on the received data in accordance with the header compression configuration.

[0142] In some example embodiments, the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane.

[0143] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS.

[0144] In some example embodiments, the apparatus further comprises: means for receiving from the network entity via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS; and means for performing header decompression on the received data in accordance with the header compression configuration.

[0145] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via the network device, capability information indicating a support for at least one of: means for the header compression for data at the layer above the AS, or means for the header compression for data transmitted via the control plane at the layer above the NAS.

[0146] In some example embodiments, the header compression configuration comprises at least one of: at least one robust header compression (ROHC) configuration, or at least one RHOC profile.

[0147] In some example embodiments, the information indicative of the header compression configuration is transmitted in one of: a non-access stratum (NAS) attach request, or a request for establishing a packet data network (PDN) connection.

[0148] In some example embodiments, the layer above the AS or above the NAS comprises at least one of: a network layer, a transport layer, or an application layer.

[0149] In some example embodiments, the header compression configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification.

[0150] In some example embodiments, a network entity capable of performing any of the method 700 (for example, the network entity 130 in FIG. 1) may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The network entity may be implemented as or included in the network entity 130 in FIG. 1.

[0151] In some example embodiments, the network entity comprises means for receiving, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS); means for applying the header compression by the network entity based on the header compression configuration in response to receiving the information; and means for transmitting, to theapparatus, information indicative of the header compression applied by the network entity.

[0152] In some example embodiments, the network entity further comprises: means for receiving from the apparatus via a network device, data with headers compressed in accordance with the header compression configuration at the layer above the AS.

[0153] In some example embodiments, the network entity further comprises: means for performing header compression for data in accordance with the header compression configuration at the layer above the AS; and means for transmitting, to the apparatus via the network device, the data with compressed headers.

[0154] In some example embodiments, the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane.

[0155] In some example embodiments, the network entity further comprises: means for receiving from the apparatus via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS.

[0156] In some example embodiments, the network entity further comprises: means for performing header compression for data in accordance with the header compression configuration at the layer above the NAS; and means for transmitting, to the apparatus via the network device, data with compressed headers via the control plane.

[0157] In some example embodiments, the network entity further comprises: means for receiving from the apparatus via the network device, capability information indicating a support for at least one of: means for the header compression for data at the layer above the AS, or means for the header compression for data transmitted via the control plane at the layer above the NAS.

[0158] In some example embodiments, the header compression configuration comprises at least one of: at least one robust header compression (ROHC) configuration, or at least one RHOC profile.

[0159] In some example embodiments, the information indicative of the header compression configuration is transmitted in one of: a non-access stratum (NAS) attach request, or a request for establishing a packet data network (PDN) connection.

[0160] In some example embodiments, the layer above the AS or above the NAS comprises at least one of: a network layer, a transport layer, or an application layer.

[0161] In some example embodiments, the network entity is a packet data network gateway (PGW).

[0162] In some example embodiments, the header compression configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification.

[0163] In some example embodiments, an apparatus capable of performing any of the method 800 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respectiveoperations of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0164] In some example embodiments, the apparatus comprises means for receiving a request for initiating a voice communication over a non-terrestrial network (NTN); means for transmitting, to a network entity via a network device, a request for establishing a packet data network (PDN) connection over the NTN in response to receiving the request for initiating the voice communication, the request for establishing the PDN connection comprising information indicative of a header compression configuration and the header compression configuration indicating the header compression for voice data transmitted at a layer above access stratum (AS); means for receiving, from the network entity via the network device, information indicative of the header compression applied by the network entity; and means for applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

[0165] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via the network device, voice data with headers compressed by the apparatus in accordance with the header compression configuration at the layer above the AS.

[0166] In some example embodiments, the apparatus further comprises: means for receiving from the network entity via the network device, voice data with headers compressed by the network entity in accordance with the header compression configuration at the layer above the AS; and means for performing header decompression on the received voice data in accordance with the header compression configuration.

[0167] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via the network device, capability information indicating a support for the header compression for voice data at the layer above the AS.

[0168] In some example embodiments, the header compression configuration comprises at least one of: at least one robust header compression (ROHC) configuration, or at least one RHOC profile.

[0169] In some example embodiments, the voice communication over the NTN utilizes user plane optimization.

[0170] In some example embodiments, the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane.

[0171] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via the network device, data via the control plane with headers compressed by the apparatus in accordance with the header compression configuration at the layer above the NAS.

[0172] In some example embodiments, the apparatus further comprises: means for receiving from the network entity via the network device, data via the control plane with headers compressed by a network entity in accordance with the header compression configuration at the layer above the NAS; and means for performing header decompression on the received data in accordance with the header compression configuration.

[0173] In some example embodiments, the apparatus further comprises: means for transmitting, to the network entity via the network device, capability information indicating a support for the header compression at the layer above the NAS for data transmitted via the control plane.

[0174] In some example embodiments, the voice communication overthe NTN utilizes control plane optimization.

[0175] In some example embodiments, the layer above the AS or above the NAS comprises at least one of: a network layer, a transport layer, or an application layer.

[0176] In some example embodiments, the header compression configuration is updated via at least one of: an update of tracking area, or a request for bearer resource modification.

[0177] FIG. 9 is a simplified block diagram of a device 900 that is suitable for implementing example embodiments of the present disclosure. The device 900 may be provided to implement a communication device, for example, the terminal device 110, the network device 120 or the network entity 130 as shown in FIG. 1. As shown, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

[0178] The communication module 940 is for bidirectional communications. The communication module 940 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 940 may include at least one antenna.

[0179] The processor 910 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 900 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0180] The memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 924, an electrically programmable read only memory (EPROM), a flash memory, a hard disk,a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 922 and other volatile memories that will not last in the power-down duration.

[0181] A computer program 930 includes computer executable instructions that are executed by the associated processor 910. The instructions of the program 930 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 930 may be stored in the memory, e.g., the ROM 924. The processor 910 may perform any suitable actions and processing by loading the program 930 into the RAM 922.

[0182] The example embodiments of the present disclosure may be implemented by means of the program 930 so that the device 900 may perform any process of the disclosure as discussed with reference to FIGs. 2 to 8. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0183] In some example embodiments, the program 930 may be tangibly contained in a computer readable medium which may be included in the device 900 (such as in the memory 920) or other storage devices that are accessible by the device 900. The device 900 may load the program 930 from the computer readable medium to the RAM 922 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e. , tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0184] FIG. 10 shows an example of the computer readable medium 1000 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1000 has the program 930 stored thereon.

[0185] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0186] Some example embodiments of the present disclosure also provide at least one computerprogram product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machineexecutable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0187] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0188] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0189] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0190] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specificimplementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable subcombination.

[0191] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

What is claimed is:

1. An apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:transmit, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS);receive, from the network entity, information indicative of the header compression applied by the network entity; andapply the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

2. The apparatus of claim 1, wherein the apparatus is caused to:transmit, to the network entity via a network device, data with header compressed in accordance with the header compression configuration at the layer above the AS.

3. The apparatus of claim 1 or 2, wherein the apparatus is caused to:receive, from the network entity via the network device, data with headers compressed in accordance with the header compression configuration at the layer above the AS; and perform header decompression on the received data in accordance with the header compression configuration.

4. The apparatus of claim 1, wherein the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane .

5. The apparatus of claim 4, wherein the apparatus is caused to:transmit, to the network entity via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS.

6. The apparatus of claim 4 or 5, wherein the apparatus is caused to:receive, from the network entity via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS; andperform header decompression on the received data in accordance with the header compression configuration.

7. The apparatus of any of claims 1 to 6, wherein the apparatus is caused to: transmit, to the network entity via the network device, capability information indicating a support for at least one of:the header compression for data at the layer above the AS, orthe header compression for data transmitted via the control plane at the layer above the NAS.

8. The apparatus of any of claims 1 to 7, wherein the header compression configuration comprises at least one of:at least one robust header compression (ROHC) configuration, orat least one RHOC profile.

9. The apparatus of any of claims 1 to 8, wherein the information indicative of the header compression configuration is transmitted in one of:a non-access stratum (NAS) attach request, ora request for establishing a packet data network (PDN) connection.

10. The apparatus of any of claims 1 to 9, wherein the layer above the AS or above the NAS comprises at least one of:a network layer,a transport layer, oran application layer.

11. The apparatus of any of claims 1 to 10, wherein the header compression configuration is updated via at least one of:an update of tracking area, ora request for bearer resource modification.

12. A network entity comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the network entity at least to:receive, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS);apply the header compression by the network entity based on the header compression configuration in response to receiving the information; andtransmit, to the apparatus, information indicative of the header compression applied by the network entity.

13. The network entity of claim 12, wherein the network entity is caused to:receive, from the apparatus via a network device, data with headers compressed in accordance with the header compression configuration at the layer above the AS.

14. The network entity of claim 11 or 12, wherein the network entity is caused to: perform header compression for data in accordance with the header compression configuration at the layer above the AS; andtransmit, to the apparatus via the network device, the data with compressed headers.

15. The network entity of claim 12, wherein the header compression configuration indicates the header compression performed at a layer above non-access stratum (NAS) for data transmitted via a control plane.

16. The network entity of claim 15, wherein the network entity is caused to:receive, from the apparatus via the network device, data via the control plane with headers compressed in accordance with the header compression configuration at the layer above the NAS.

17. The network entity of claim 15 or 16, wherein the network entity is caused to: perform header compression for data in accordance with the header compression configuration at the layer above the NAS; andtransmit, to the apparatus via the network device, data with compressed headers via thecontrol plane.

18. The network entity of any of claim 12 to 17, wherein the network entity is caused to: receive, from the apparatus via the network device, capability information indicating a support for at least one of:the header compression for data at the layer above the AS, orthe header compression for data transmitted via the control plane at the layer above the NAS.

19. The network entity of any of claim 12 to 18, wherein the header compression configuration comprises at least one of:at least one robust header compression (ROHC) configuration, orat least one RHOC profile.

20. The network entity of any of claim 12 to 19, wherein the information indicative of the header compression configuration is transmitted in one of:a non-access stratum (NAS) attach request, ora request for establishing a packet data network (PDN) connection.

21. The network entity of any of claim 12 to 20, wherein the layer above the AS or above the NAS comprises at least one of:a network layer,a transport layer, oran application layer.

22. The network entity of any of claim 12 to 21 , wherein the network entity is a packet data network gateway (PGW).

23. The network entity of any of claim 12 to 22, wherein the header compression configuration is updated via at least one of:an update of tracking area, ora request for bearer resource modification.

24. A method comprising:transmitting, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS);receiving, from the network entity, information indicative of the header compression applied by the network entity; andapplying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

25. A method comprising:receiving, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS);applying the header compression by the network entity based on the header compression configuration in response to receiving the information; andtransmitting, to the apparatus, information indicative of the header compression applied by the network entity.

25. An apparatus comprising:means for transmitting, to a network entity, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS);means for receiving, from the network entity, information indicative of the header compression applied by the network entity; andmeans for applying the header compression by the apparatus based on the header compression configuration and the information indicative of the header compression applied by the network entity.

26. A network entity comprising:means for receiving, from an apparatus, information indicative of a header compression configuration, the header compression configuration indicating a header compression for data transmitted at a layer above access stratum (AS);means for applying the header compression by the network entity based on the header compression configuration in response to receiving the information; andmeans for transmitting, to the apparatus, information indicative of the header compression applied by the network entity.

27. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 24 or the method of claim 25.

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