Patent Publication Number: US-2021185560-A1

Title: Transmitting Device, Receiving Device, and Methods Performed Therein for Handling Uplink Data Compression

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a transmitting device and methods performed thereby for handling uplink data compression. The present disclosure also relates generally to a receiving device and methods performed thereby for handling uplink data compression. 
     BACKGROUND 
     Communication devices within a wireless communications network may be wireless devices such as e.g., User Equipments (UEs), stations (STAs), mobile terminals, wireless terminals, terminals, and/or Mobile Stations (MS). Wireless devices are enabled to communicate wirelessly in a cellular communications network or wireless communication network, sometimes also referred to as a cellular radio system, cellular system, or cellular network. The communication may be performed e.g., between two wireless devices, between a wireless device and a regular telephone, and/or between a wireless device and a server via a Radio Access Network (RAN), and possibly one or more core networks, comprised within the wireless communications network. Wireless devices may further be referred to as mobile telephones, cellular telephones, laptops, or tablets with wireless capability, just to mention some further examples. The wireless devices in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the RAN, with another entity, such as another terminal or a server. 
     Communication devices may also be network nodes, such as radio network nodes, e.g., Transmission Points (TP). The wireless communications network covers a geographical area which may be divided into cell areas, each cell area being served by a network node such as a Base Station (BS), e.g., a Radio Base Station (RBS), which sometimes may be referred to as e.g., a gNB, evolved Node B (“eNB”), “eNodeB”, “NodeB”, “B node”, or BTS (Base Transceiver Station), depending on the technology and terminology used. The base stations may be of different classes such as e.g., Wide Area Base Stations, Medium Range Base Stations, Local Area Base Stations and Home Base Stations, based on transmission power and thereby also cell size. A cell is the geographical area where radio coverage is provided by the base station at a base station site. One base station, situated on the base station site, may serve one or several cells. Further, each base station may support one or several communication technologies. The wireless communications network may also be a non-cellular system, comprising network nodes which may serve receiving nodes, such as wireless devices, with serving beams. In 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), base stations, which may be referred to as eNodeBs or even eNBs, may be directly connected to one or more core networks. In the context of this disclosure, the expression Downlink (DL) may be used for the transmission path from the base station to the wireless device. The expression Uplink (UL) may be used for the transmission path in the opposite direction i.e., from the wireless device to the base station. 
     A work on Uplink Data Compression (UDC) in LTE has been brought in Release (Rel)-15 of LTE [5]. The motivation for this work item is that the air interface may get congested and hence it may, in some scenarios, be beneficial to compress the data in Uplink before it may be sent over the air interface. 
     The proposed solution is that in the Packet Data Convergence Protocol (PDCP) layer of LTE it is introduced the possibility to compress Service Data Units (SDUs) at the transmitter. The receiver may then, upon reception of a packet, decompress the data and forward the result to higher layers. The compression solution is based upon “DEFLATE” [1,3]. 
     Compression may be either lossless or lossy. In Lossless compression, the receiver may be able to reconstruct the packet exactly as how it was in the sender. In lossy compression, there may be some loss, but the receiver may still interpret the data; although this may not be the exact copy of the original. DEFLATE is a lossless data compression algorithm that combines the table based LZ77 algorithm and Huffman encoding. The LZ77 algorithm achieves compression by replacing repeated occurrences of data with an 8+15 bit &lt;length, distance&gt;-pair that specifies an earlier copy of the data in the previous uncompressed data stream. The length parameter indicates the length of the matching copy of data, and the distance parameter indicates how far back in the previous uncompressed data stream the duplicate occurred. To find matches, the compressor may need to keep a certain amount of the most recent data in a sliding window buffer. In the same way, the decompressor may need to have access to the same data to be able to interpret the matches referred to in the compressed packet. For compression/de-compression to work, it may be understood to be necessary that the buffered data on the compressor and the decompressor side are synchronized; any loss of data may force the algorithm out-of-synch. 
     In the DEFLATE algorithm, the length of the matching pattern is restricted to 3-258 bytes, with a lookback length (distance) of maximum 32 KB. Matches may be made between any number of blocks, as long as the match occurs within the last 32 KB of the uncompressed data stream. For application to UL data compression, blocks may be interchanged with packets. 
     In a second compression stage, DEFLATE may compress the previously uncompressed part, that is, literal part, of the block by Huffman coding. The Huffman coding may be understood to work by replacing commonly used symbols with code shorter representations, while longer code representations may be used for less commonly used symbols. The Huffman code dictionary, also known as the Huffman tree, may be calculated based on a given alphabet and the frequency of the different symbols in the data. The DEFLATE algorithm may work with either a pre-set Huffman code dictionary, or dynamically by calculating a new Huffman tree for each block. If dynamic Huffman coding is used, the Huffman tree may be understood to be required to be included in the compressed packet. On the other hand, better compression may be expected if the tree is tailor made for each packet. 
     UDC algorithm based upon DEFLATE may need to have a buffer memory context on the compressor and decompressor side. For example, to perform cross-packet compression, a First-In-First-Out (FIFO) buffer may be used to buffer original packets which have been compressed. Within the packets which have not been compressed, if a repeated string in buffer is identified, a back-reference may be inserted linking it to the previous location and the length of that identified string as shown in  FIG. 1 .  FIG. 1  is a schematic diagram illustrating an example of Deflate before compression in panel a), and after compression, in panel b). In  FIG. 1 , the buffer size in the compression entity, e.g., a UE, is 8 bytes. Each byte is numbered from 0 to 7. When a new packet which has a content of “bcd”, as illustrated on the right side of panel a), comes in to the compression entity, a cross-packet match may be identified in the buffer, with the previous position  6 , length  3 . The new packet, which original length is 3 bytes, may be compressed to 6 bits, as illustrated on the left side of panel b), that is, 3 bits to identify any of the 8 positions in the buffer where the match starts, and 3 bits for length. After compression, the new packet is inserted in the buffer. The decompressor similarly has a decompression entity with same buffer content so that it may decompress the compressed packet. If decompressor and compressor buffer content is out-of-sync, it would be impossible to re-construct the original packet in the decompressor side. The decompressor thus may be understood to need to be able to inform the compressor about this sort of error scenario. After the notification, the compressor, e.g., the UE, may need to reset its buffer and attempt for compression again. 
     A checksum failure may be understood as an error indicating that the sender and receiver buffer are out of sync. If there are multiple checksum failures in a short interval, an eNB may decide to release the UDC configuration. To release the UDC configuration may be understood to mean to not use compression in the uplink. Similarly, the compressor, e.g., the UE, because of some software error, may point to out of memory for the decompressor, e.g., the eNB, to decompress the packet. For example, if the buffer size has been set to 2 kilobytes, that is, 2048 bytes, but the sender points to a memory size of 3000 bytes; then this is an error. In such error case, the eNB may decide to release the UDC configuration. The purpose of the UDC is to save UL bandwidth; however, if there is not any substantial compression gain achieved, the eNB may decide to release the UDC configuration. 
     Handling of the uplink data compression according existing methods may lead to ambiguity in the communications between the compressor and the decompressor and wastage of processing and energy resources, as well as delays. 
     SUMMARY 
     It is an object of embodiments herein to improve the efficiency of usage of resources in a communications network. It is a particular object of embodiments herein to improve the efficiency of usage of resources in a communications network by improving the handling of uplink data compression. 
     According to a first aspect of embodiments herein, the object is achieved by a method performed by a transmitting device. The transmitting device operates in a communications network. The transmitting device receives an indication from a receiving device. The receiving device operates in the communications network. The indication instructs the transmitting device to perform a buffer reset. The indication is a value in a field in a PDU received from the receiving device. The transmitting device then resets the buffer, based on the received indication. 
     According to a second aspect of embodiments herein, the object is achieved by a method performed by the receiving device. The receiving device operates in the communications network. The receiving device sends the indication to the transmitting device operating in the communications network. The indication instructs the transmitting device to perform the buffer reset. The indication is the value in the field in the PDU sent to the transmitting device. 
     According to a third aspect of embodiments herein, the object is achieved by the transmitting device, configured to operate in the communications network. The transmitting device is further configured to receive the indication from the receiving device configured to operate in the communications network. The indication is configured to instruct the transmitting device to perform the buffer reset. The third indication is configured to be the value in the field in the PDU, configured to be received from the receiving device. The transmitting device is further configured to reset the buffer, based on the third indication configured to be received. 
     According to a fourth aspect of embodiments herein, the object is achieved by the receiving device, configured to operate in the communications network. The receiving device is configured to send the indication to the transmitting device configured to operate in the communications network. The indication is configured to instruct the transmitting device to perform the buffer reset. The indication is configured to be the value in the field in the PDU, configured to be sent to the transmitting device. 
     According to a fifth aspect of embodiments herein, the object is achieved by a computer-readable storage medium, having stored thereon the computer program, comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method performed by the transmitting device. 
     According to an sixth aspect of embodiments herein, the object is achieved by a computer-readable storage medium, having stored thereon the computer program, comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method performed by the receiving device. 
     By the transmitting device receiving the indication from the receiving device, instructing the transmitting device to perform the buffer reset with the value in the PDU, processing and energy resources in the communications network may be used more efficiently, as the delay in providing the indication is reduced, in comparison with e.g., RRC signalling in existing methods. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Examples of embodiments herein are described in more detail with reference to the accompanying drawings, and according to the following description. 
         FIG. 1  is a schematic diagram illustrating data compression, according to existing methods. 
         FIG. 2  is a schematic diagram illustrating an example of a packet format with a UDC header, according to existing methods. 
         FIG. 3  is a schematic diagram illustrating an example of a packet format without a UDC header, according to existing methods. 
         FIG. 4  is a schematic diagram illustrating a communications network, according to embodiments herein. 
         FIG. 5  is a flowchart depicting embodiments of a method in a transmitting device, according to embodiments herein. 
         FIG. 6  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. 
         FIG. 7  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. 
         FIG. 8  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. 
         FIG. 9  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. 
         FIG. 10  is a flowchart depicting a method in a receiving device, according to embodiments herein. 
         FIG. 11  is a schematic block diagram illustrating two non-limiting examples, a) and b), of a transmitting device, according to embodiments herein. 
         FIG. 12  is a schematic block diagram illustrating two non-limiting examples, a) and b), of a receiving device, according to embodiments herein. 
         FIG. 13  is a flowchart depicting an example of a method in a transmitting device, related to embodiments herein. 
         FIG. 14  is a flowchart depicting an example of a method in a receiving device, related to embodiments herein. 
         FIG. 15  is a schematic block diagram illustrating a telecommunication network connected via an intermediate network to a host computer, according to embodiments herein. 
         FIG. 16  is a generalized block diagram of a host computer communicating via a base station with a user equipment over a partially wireless connection, according to embodiments herein. 
         FIG. 17  is a flowchart depicting embodiments of a method in a communications system including a host computer, a base station and a user equipment, according to embodiments herein. 
         FIG. 18  is a flowchart depicting embodiments of a method in a communications system including a host computer, a base station and a user equipment, according to embodiments herein. 
         FIG. 19  is a flowchart depicting embodiments of a method in a communications system including a host computer, a base station and a user equipment, according to embodiments herein. 
         FIG. 20  is a flowchart depicting embodiments of a method in a communications system including a host computer, a base station and a user equipment, according to embodiments herein. 
     
    
    
     DETAILED DESCRIPTION 
     As part of the development of embodiments herein, one or more problems with the existing technology will first be identified and discussed. 
     When UDC is configured, a packet format such as that depicted in  FIG. 2  may be used [4]. As shown in  FIG. 2 , the packet format comprises four octets: a first octet (Oct 1)  201 , a second octet (Oct 2)  202 , a third octet (Oct 3)  203  and a fourth octet (Oct 4)  204 . The first octet  201  comprises a Data/Control PDU (D/C) field  205 , a first reserved (R) field  206 , a second R field  207 , a third R field  208 , and a Packet Data Convergence Protocol Sequence Number (PDCP SN) field  209 . The second octet  202  comprises a continuation of the PDCP SN field  210 . The third octet  203  comprises a Field UDC (FU) field  211 , a fourth R filed  212 , a fifth R field  213 , a sixth R field  214 , and checksum field  215 . The fourth octet  204  comprises a UDC data block  216 . 
     When UDC is not configured, a legacy packet format without UDC header may be used instead [ 2 , 4 ], as depicted in  FIG. 3 . This format comprises three octets: a first octet (Oct 1)  301 , a second octet (Oct 2)  302 , and a third octet (Oct 3)  303 . As may be appreciated by comparing  FIG. 2  and  FIG. 3 , the third octet is different for the two formats. After the UDC configuration is released e.g., because of an error, the compressor, e.g., a UE, may then fall back to a legacy method, that is, it may send packets without a UDC header as depicted in  FIG. 3 . However, the decompressor, e.g., eNB would not know if the packet is still processed by the UDC entity or not. That is, the decompressor will not be able to identify if the third octet is the UDC header, that is, FU  212 ; R  212 ; R  213 ; R  214 ; Checksum  215 , as shown in the first format in  FIG. 2 , or if it is Data  304 , as shown in the second format in  FIG. 3 . Therefore, there will be ambiguity. For example, if a UE is sending compressed packets, but the eNB receiving them assumes they are legacy packets, the packets will not be uncompressed by the eNB. Thus, these compressed packets will not be readable by the application layer. Similarly, if a UE sends uncompressed packets, and the eNB receiving them assumes they are compressed packets, there will be extra processing in the eNB to try to decompress the packets. This may lead to corruption of the packets. Hence, it is advantageous to avoid this ambiguity. 
     Certain aspects of the present disclosure and their embodiments may provide solutions to this challenge or other challenges. There are, proposed herein, various embodiments which address one or more of the issues disclosed herein. 
     Embodiments herein may be understood to address this problem in existing methods by the compressor, that is, a transmitting device such as a UE, sending an indication to the decompressor, that is, a receiving device such as an eNB, indicating whether the uplink data compression, e.g., UDC, is enabled or disabled. Embodiments herein may be understood to relate to a method to provide feedback from a compressor to a decompressor for release of uplink data compression, e.g., UDC. In general terms, embodiments herein may therefore be understood to be related to a method for providing feedback for Uplink Data Compression. 
     Uplink data compression may be handled by another uplink data compression feature with similar functional characteristics to UDC. UDC is used herein as an illustrative example of an uplink data compression feature. 
     As a brief overview of embodiments herein, and taking UDC as an example of uplink data compression, if at first UDC is enabled/active, the packets that may be sent by the transmitting device may be compressed using the UDC-algorithm. When UDC is disabled/deactivated, the packets sent by the transmitting device may not be compressed using the UDC-algorithm. Upon switching from a state where UDC is enabled/active to disabled/deactivated, or vice versa, the transmitting device may generate and transmit a message with the indication to a receiving device. 
     New PDCP Control PDU packets, may be defined, according to particular embodiments herein, to provide the feedback from the compressor to the decompressor. 
     Some of the embodiments contemplated will now be described more fully hereinafter with reference to the accompanying drawings, in which examples are shown. In this section, the embodiments herein will be illustrated in more detail by a number of exemplary embodiments. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art. It should be noted that the exemplary embodiments herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. 
     Note that although terminology from LTE has been used in this disclosure to exemplify the embodiments herein, this should not be seen as limiting the scope of the embodiments herein to only the aforementioned system. Other wireless systems with similar features, may also benefit from exploiting the ideas covered within this disclosure. 
       FIG. 4  depicts a non-limiting example of a communications network  100 , sometimes also referred to as a wireless communications system, cellular radio system, or cellular network, in which embodiments herein may be implemented. The communications network  100  may typically be a Long-Term Evolution (LTE) network, e.g., LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), LTE Half-Duplex Frequency Division Duplex (HD-FDD), LTE operating in an unlicensed band. The communications network  100  may otherwise, or in addition, support other technologies and be for example a 5G system, 5G network, NR, LTE-NR Dual Connectivity, or Next Gen System or network, Wideband Code Division Multiple Access (WCDMA), Universal Terrestrial Radio Access (UTRA) TDD, Global System for Mobile Communications (GSM) network, GSM/Enhanced Data Rate for GSM Evolution (EDGE) Radio Access Network (GERAN) network, Universal Mobile Telecommunications System (UMTS), Ultra-Mobile Broadband (UMB), EDGE network, network comprising of any combination of Radio Access Technologies (RATs) such as e.g. Multi-Standard Radio (MSR) base stations, multi-RAT base stations etc., and/or other suitable 2G, 3G, 4G, or 5G network, wireless local area network (WLAN) network, Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee network, or any cellular network or system. Thus, although terminology from 3GPP LTE has been used in this disclosure to exemplify embodiments herein, this should not be seen as limiting the scope of the embodiments herein to only the aforementioned system. Other wireless systems, especially 5G/NR or LTE-NR Dual Connectivity, WCDMA, WiMax, UMB and GSM, may also benefit from exploiting the ideas covered within this disclosure. 
     The communications network  100  comprises a plurality of communication devices or nodes, whereof a transmitting device  101 , and a receiving device  102  are depicted in the non-limiting example of  FIG. 4 . The transmitting device  101  may be also referred to as a compressor, or compressor device. The receiving device  102  may be also referred to as a decompressor, or decompressor device. The receiving device  102  may typically be a network node, such as a network node  110  described below, e.g., a base station. The transmitting device  101  may typically be a wireless device, such as the wireless device  130  described below. 
     In other examples which are not depicted in  FIG. 4 , any of the transmitting device  101  and the receiving device  102  may be wireless devices such as the wireless device  130 , e.g., D2D devices. In yet other examples which are not depicted either in  FIG. 4 , any of the transmitting device  101  and the receiving device  102  may be network nodes such as the network node  110 . 
     The communications network  100  comprises a plurality of network nodes, whereof a network node  110  is depicted in the non-limiting example of  FIG. 4 . The network node  110  may be a radio network node. That is, a transmission point such as a radio base station, for example an eNB, a New Radio (NR) NodeBs (gNBs), or any other network node with similar features capable of serving a wireless device, such as a user equipment or a machine type communication device, in the communications network  100 . 
     The communications network  100  covers a geographical area which may be divided into cell areas, wherein each cell area may be served by a network node, although, one radio network node may serve one or several cells. The communications network  100  comprises at least a cell  120 . In the non-limiting example depicted in  FIG. 4 , the network node  110  serves the serving cell  120 . Even in examples wherein the communications network  100  may not be referred to as a cellular system, if the network node  110  serves receiving nodes, such as the wireless device  130 , with serving beams, the areas of coverage of the beams may still be referred to as cells. The network node  110  may be of different classes, such as, e.g., macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. The network node  110  may support one or several communication technologies, and its name may depend on the technology and terminology used. In LTE, the network node  110 , which may be referred to as an eNB, may be directly connected to one or more core networks, which are not depicted in  FIG. 4  to simplify the Figure. In some examples, the network node  110  may be a distributed node, such as a virtual node in the cloud, and it may perform its functions entirely on the cloud, or partially, in collaboration with a radio network node. 
     A plurality of wireless devices are located in the wireless communication network  100 , whereof a wireless device  130 , which may also be referred to as a device, is depicted in the non-limiting example of  FIG. 4 . The wireless device  130  comprised in the communications network  100  may be a wireless communication device such as a UE, or a 5G UE, which may also be known as e.g., a mobile terminal, wireless terminal and/or mobile station, a mobile telephone, cellular telephone, or laptop with wireless capability, just to mention some further examples. Any of the wireless devices comprised in the communications network  100  may be, for example, portable, pocket-storable, hand-held, computer-comprised, or a vehicle-mounted mobile device, enabled to communicate voice and/or data, via the RAN, with another entity, such as a server, a laptop, a Personal Digital Assistant (PDA), or a tablet, Machine-to-Machine (M2M) device, device equipped with a wireless interface, such as a printer or a file storage device, modem, or any other radio network unit capable of communicating over a radio link in a communications system. The wireless device  130  comprised in the communications network  100  is enabled to communicate wirelessly in the communications network  100 . The communication may be performed e.g., via a RAN, and possibly the one or more core networks, which may comprised within the communications network  100 . 
     The transmitting device  101  may be configured to communicate within the communications network  100  with the receiving device  102  over a link  140 , e.g., a radio link. 
     Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description. 
     In general, the usage of “first”, “second”, “third”, “fourth” and/or “fifth” herein may be understood to be an arbitrary way to denote different elements or entities, and may be understood to not confer a cumulative or chronological character to the nouns they modify. 
     Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. 
     More specifically, the following are: a) embodiments related to a transmitting device, such as the transmitting device  101 , e.g., a UE; and b) embodiments related to a receiving device, such as the receiving device  102 , e.g., an eNB. The transmitting device  101  may also be referred to as a compressor, and the receiving device  102  may also be referred to as a decompressor. 
     Some embodiments herein will be described with some non-limiting examples. In the following description any reference to a/the UE and/or a/the compressor may be understood to equally apply to the transmitting device  101 , and any reference to a/the eNB, and/or a/the network and/or a/the decompressor may be understood to equally apply to the receiving device  102 . Any reference to a/the UDC may be understood to be a non-limiting example of an uplink data compression. Any of the examples provided here may be understood to be able to be combined with the embodiments herein, described earlier. 
     Embodiments of a method, performed by the transmitting device  101 , will now be described with reference to the flowchart depicted in  FIG. 5 . The method may be considered to be for handling uplink data compression. The transmitting device  101  operates in the communications network  100 . 
     The method, performed by the transmitting device  101  may comprise two or more of the following actions. In some embodiments all the actions may be performed. In some embodiments, two or more actions may be performed. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. In  FIG. 5 , optional actions are indicated with dashed lines. Some actions may be performed in a different order than that shown in  FIG. 5 . 
     Action  501   
     In order for a device sending information and a device receiving the information to identify a state of their communication, such as e.g., any error encountered, or to identify an enable or disable state, or in order to “activate” and “deactivate” UDC, existing methods assume that this is done via Radio Resource Control (RRC) signalling. RRC signalling may be relatively slow and a UE processing of RRC signalling may take place in a time-window, which may be from 0 to 15 ms after the signalling may have been received. During this time window, an eNB is not certain if the UE has applied the RRC signalling or not and hence, the eNB may be unware of if the packet transmitted is based upon UDC before reset or after reset, whether UDC was enabled/active or disabled/deactivated in the UE during the time window, and the eNB may not even know when the time window occurs in the UE. In case of activating and deactivating UDC via RRC, it may be that the eNB is unaware of the state of the UE. 
     To address this problem, in this Action  501 , the transmitting device  101  may receive a first indication from the receiving device  102 . The first indication may indicate an instruction, such as a preference, to the transmitting device  101 , to activate or deactivate an uplink data compression feature. 
     The uplink data compression feature may be e.g., UDC in LTE. 
     Receiving may be understood as e.g., collecting or obtaining. The receiving  501  may be performed via the link  140 . 
     The first indication may be a PDCP message that may be received from the receiving device  102 , e.g., an eNB, by the transmitting device  101 , e.g., a UE, to indicate whether UDC is to be activated or deactivated by the UE. The transmitting device  101  may, upon reception of the first indication, activate UDC, if the first indication is set to a value, and deactivate UDC, if the first indication is set to another value. An example of how this first indication may be defined may be with an “Activate/Deactivate (A/D) field” of length: 1 bit. The “A/D” field just described is schematically depicted in the control PDU represented in any of  FIG. 6 ,  FIG. 7  and  FIG. 9 . 
     Table 1 shows an example of how this first indication may be defined in an “Activate/Deactivate (A/D) field” of length: 1 bit. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 A/D field 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 0 
                 Deactivate UDC 
               
               
                 1 
                 Activate UDC 
               
               
                   
               
            
           
         
       
     
     In one other example according to embodiments herein, the other reserved (R) bits in an octet, such as those depicted in any of  FIG. 6 ,  FIG. 7  and  FIG. 9 , may be utilized among the decompressor, that is, the receiving device  102 , and the compressor, that is, the transmitting device  101 , for effective communication to handle other error scenarios or to provide feedback. 
     For instance, in another example of the first indication, one of the reserved bits may be used as a Load (“L”) field, as shown in the examples of  FIG. 7  and  FIG. 9 . As shown in Table 2, the receiving device  102  may ask the transmitting device  101  to stop compression temporarily, by setting a pre-defined timer, if, e.g., the receiving device  102  is heavily loaded. For example, when L field may be set to “1”, the UDC may be disabled for a certain pre-defined duration. After the expiry of the duration, UDC may be applied again. This may be understood as another example of the first indication. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 L field 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 0 
                 Normal Operation 
               
               
                 1 
                 Temporarily Deactivate UDC because of high 
               
               
                   
                 Load 
               
               
                   
               
            
           
         
       
     
     An alternative approach may be that the first indication does not have an explicit indication of whether the transmitting device  101  is to activate/enable or deactivate/disable UDC, but rather the reception of the first indication itself may be an implicit indication that the transmitting device  101  is to switch state, for example, disable/deactivate UDC if UDC currently is enabled/active, and enable/activate UDC if UDC currently is disabled/deactivated. This implicit indication may be that the transmitting device  101  may receive a PDU of a certain type, that is, with a certain value of a field “PDU type” as shown in Table 3. Table 3 shows an example of how this first indication may be defined in a “PDU Type field” of length: 3 bits. The PDU type-field used may be the already existing PDU field, but set to a new value to indicate that this PDU is a UDC feedback packet, e.g., to the value 011, as shown in Table 3. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 PDU type 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 000 
                 PDCP status report 
               
               
                 001 
                 Interspersed ROHC feedback packet 
               
               
                 010 
                 LWA status report 
               
               
                 011 
                 UDC Feedback Packet 
               
               
                 100-111 
                 reserved 
               
               
                   
               
            
           
         
       
     
     The PDU type field just described is exemplified later in the PDCP Control PDU for UDC feedback packet represented in any of  FIG. 6 ,  FIG. 7 , and  FIG. 9 . 
     According to the foregoing, the first indication may be at least one of: a) a first value in a first field of a first PDU, the first field indicating a type of the PDU, as e.g., shown in Table 3, and b) a second value in a second field of the first PDU, the second field indicating at least one of: a) an Activate/Deactivate (A/D) state, as e.g., shown in Table 1, and b) a Normal Operation/Temporary Deactivation state, as e.g., shown in Table 2. 
     The first field may be e.g., the “PDU Type” field just described and exemplified in Table 3, which is also depicted later, in any of  FIG. 6 ,  FIG. 7 , and  FIG. 9 . 
     In some particular examples, the first value may be 1 bit. The first value may be 0 or 1. 
     The second field may be e.g., the “A/D” field just described and exemplified in Table 1, which is also depicted later, in any of  FIG. 6 ,  FIG. 7  and  FIG. 9 . The second field may be, alternatively, or additionally, as depicted in  FIG. 7  and  FIG. 9 , the “L” field, as e.g., described in Table 2. 
     By performing this Action  501 , the transmitting device  101  may enable the receiving device  102  to exert control of UDC activation by the transmitting device  101 , and thereby enable the receiving device  102  to be aware of whether the UDC is enabled/active or disabled/deactivate in the transmitting device  101 . 
     Action  502   
     The transmitting device  101  may, upon reception of the first indication, activate or enable UDC, if the first indication is set to a value, and deactivate or disable UDC, if the first indication is set to another value. After making this change, the transmitting device  101  may let the receiving device  102  know what its new state is. Accordingly, in this Action  502 , the transmitting device  101  may, send a second indication to the receiving device  102 . The first indication described in Action  501  may be understood as another indication. The second indication may be comprised in a control PDU. The second indication may indicate one of: a) the uplink data compression feature is enabled in the transmitting device  101  and a header comprising information about the enabled uplink data compression feature of one or more data PDUs is to be present in the one or more data PDUs to be sent by the transmitting device  101  after sending the second indication, and b) the uplink data compression feature is disabled in the transmitting device  101  and the header comprising information about the enabled uplink data compression of one or more data PDUs is to be absent in the one or more data PDUs to be sent by the transmitting device  101  after sending the second indication. 
     The sending in this Action  502  may be performed e.g., via the link  140 . Sending may also be understood as transmitting. 
     The sending of the second indication in this Action  502  may be understood as an indication of UDC status to the receiving device  102 . 
     The header may be e.g., the header depicted in  FIG. 2 , in Octate 3 (Oct 3)  203 . 
     Examples of Implementation of the Second Indication 
     One way of implementing the second indication may be by using a certain PDU type, e.g., a PDCP control PDU type. The transmitting device  101 , e.g., a UE, may then generate such a PDU type and transmit it to the receiving device  102 . The receiving device  102 , e.g., an eNB, may, upon reception of this PDU type, know that the transmitting device  101  has switched from a state. For example, if the transmitting device  101  first was in a state where UDC was enabled/active, but UDC becomes disabled/deactivated, the transmitting device  101  may generate and send the new PDU type to the receiving device  102 , and the receiving device  102  may then know that any packet received after this PDU type has not been processed by the UDC algorithm in the transmitting device  101 . Or if the transmitting device  101  first was in a state where UDC was disabled/deactivated, but UDC becomes enabled/activated, the transmitting device  101  may generate and send the new PDU type to the receiving device  102 , and the receiving device  102  may then know that any packet received after this PDU type has been processed by the UDC algorithm in the transmitting device  101 . 
     Accordingly, in some embodiments, the second indication may indicate a third value in a third field of the control PDU, the third field indicating the type of PDU. The third field may be e.g., the “PDU Type” field depicted in  FIG. 8 . The third value may be 3 bit. The third value may be 011. 
     It may be noted, that in some situations, packets received by the receiving device  102  may not be in the same order as the transmitting device  101  may have generated them. To solve this, the transmitting device  101  may, according to some embodiments, indicate a sequence number to the receiving device  102 . The sequence number may indicate which is the last packet before the switch happened, or it may indicate the first packet after the switch. 
     According to the foregoing, in some embodiments, the second indication may further indicate one of: a) a sequence number of a last packet sent by the transmitting device  101  before an enabled or disabled state of the transmitting device  101  switched; and b) a sequence number of a first packet sent by the transmitting device  101  after the enabled or disabled state of the transmitting device  101  switched. 
     The PDU comprising flag bits, which may serve as the second indication in some embodiments, may further have an explicit indication indicating whether UDC is enabled or disabled by the transmitting device  101 . An example of such other second indication may be defined in an Enabled/Disabled (E/D) field. An example implementation of this is shown in  FIG. 8 , where a new PDCP Control PDU for UDC is used, and an E/D indication is set to a first value, e.g., 1 or 0, if UDC is enabled in the transmitting device  101 , or to a second value, e.g. 0, or 1, if UDC is disabled. In the particular example depicted in Table 4, 0 indicates that UDC is enabled, and 1 indicates that UDC is disabled. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 E/D field 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 0 
                 UDC enabled 
               
               
                 1 
                 UDC disabled 
               
               
                   
               
            
           
         
       
     
     One benefit of having an explicit indication of the enabled/disabled state in the transmitting device  101  is that the receiving device  102  may be enabled to not need to consider which state the transmitting device  101  was in prior to receiving the second indication, in order to understand what the second indication means. E.g., if the transmitting device  101  does not include such an explicit indication, the receiving device  102  would have to know whether UDC is enabled or disabled in the transmitting device  101  to be able to understand if the second indication means that the transmitting device  101  has disabled or enabled UDC, while if an explicit indication is provided to the receiving device  102  by the transmitting device  101 , the receiving device  102  may know this by determining the value of the second indication. 
       FIG. 8  depicts a schematic visual representation of a new PDU type where the new E/D indication, that is, the E/D field, is included. However, as stated above, in some embodiments, the E/D indication may not be present but rather the second indication may be only a PDU of type which implicitly indicates that the switch has taken place or will take place, e.g., after  10  packets ora packet with sequence number X, UDC will be enabled/disabled. 
     A particular example of how the transmitting device  101  may set the values in the PDU type is shown next. 
     First, the already existing Data/Control (D/C)-indication, the D/C field, may be set to 0 to indicate that this is a Control PDU, as shown in Table 5. The D/C field may have a length of 1 bit. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 D/C field 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 0 
                 Control PDU 
               
               
                 1 
                 Data PDU 
               
               
                   
               
            
           
         
       
     
     Further, the already existing PDU type-field may be included, but set to a new value to indicate that this PDU is a UDC feedback packet, e.g., to the value 011, as shown in Table 3. 
     And in case an explicit indication of whether UDC is enabled/disabled, e.g. by means of the E/D-field, then the second indication may be defined as shown in Table 4. 
     According to the foregoing, the second indication may be one of: a) the third value in a third field of the control PDU, the third field indicating a type of PDU, and b) a fourth value in a fourth field of the control PDU, the fourth field indicating an Enabled/Disabled (E/D) state. 
     The fourth field may be e.g., the “E/D” field depicted in  FIG. 8 . 
     The fourth value, e.g., any of the values in Table 4, may be 1 bit. The fourth value may be 0 or 1. 
     By the transmitting device  101  sending the second indication to the receiving device  102 , indicating whether the uplink data compression features is enabled or disabled and whether the header is going to be present or absent in the one or more data PDUs to be sent by the transmitting device  101  after sending the indication, the transmitting device  101  may enable the receiving device  102  to know how to read the one or more data PDUs, and to know if the one or more data PDUs are compressed or not. Therefore, the receiving device  102  may process the one or more data PDUs accordingly. Consequently, processing and energy resources in the communications network  100  may be used more efficiently. 
     Action  503   
     Sending the control PDU of Action  502  may not only enable the receiving device  102  to be aware of the state of the transmitting device  101 , but also to detect if the compression buffer of the transmitting device  101  and decompression buffer of the receiving device  102  may be out of synchronization, e.g., by detecting a checksum error. If such an error is detected, the receiving device  102  may then notify the transmitting device  101  about the error and attempt to handle it by requesting that the transmitting device  101  perform a buffer reset. Accordingly, in this Action  503 , the transmitting device  101  receives a third indication from the receiving device  102  operating in the communications network  100 . The third indication instructs the transmitting device  101  to perform a buffer reset. The third indication is a fifth value in a fifth field in a second PDU received from the receiving device  102 . The third indication received in this Action  503  may be simply referred to herein as “the indication”. The fifth field in this Action  503  may be simply referred to herein as “the field”, and the second PDU may be referred to herein as “the PDU”. The PDU may be a PDCP control PDU. 
     The receiving in this Action  503  may be performed via the link  140 . 
     The second PDU may be understood to be a PDU received at a later time point than the first PDU described in Action  501 . 
     The fifth field may be e.g., the Reset (“RE”) field depicted in  FIG. 9 . 
     The fifth value may be 1 bit. The fifth value may be 0 or 1. 
     A particularly effective means to convey that the transmitting buffer  101  is to reset the buffer may be by the use of PDCP control PDU packet as shown in  FIG. 9 . According to embodiments herein, one of the bits as part of the newly defined PDCP control PDU packet may be used by the receiving device  102  to inform the transmitting device  101  that a reset of buffer is needed, as shown in Table 6. The fifth field may be e.g., the “RE” field depicted in  FIG. 9 . The fifth value may be 1 bit. The fifth value may be 0 or 1. 
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 RE field 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 0 
                 Normal operation/unused 
               
               
                 1 
                 Perform Buffer Reset 
               
               
                   
               
            
           
         
       
     
     By receiving the third indication in this Action  503 , the transmitting device  101  may be enabled to initiate correcting any lack of synchronization between the compression buffer and the decompression buffer, on the side of the transmitting device  101 , and resynchronize the compression buffer, which may be understood to enable to solve the buffer mismatch issue and allow UDC to be applied again. 
     Action  504   
     In this Action  504 , the transmitting device  101  resets the buffer, based on the received indication, that is, the received third indication. 
     By resetting the buffer in this Action  504 , the transmitting device  101  may resynchronize the compression buffer, which may be understood to enable UDC to be initiated again. 
     Action  505   
     In this Action  505 , the transmitting device  101  may send a fourth indication to the receiving device  102 . The fourth indication may indicate that a buffer reset has been performed. 
     The sending  505  may be performed via the link  140 . 
     Similarly to how it was described in Action  503 , a bit from the transmitting device  101  to the receiving device  102  may subsequently be used to convey that the reset has been performed, as shown in Table 7. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 RE field 
               
            
           
           
               
               
            
               
                 Bit 
                 Description 
               
               
                   
               
               
                 0 
                 Normal operation/unused 
               
               
                 1 
                 Buffer Resest is done 
               
               
                   
               
            
           
         
       
     
     By sending the fourth indication in this Action  504 , the transmitting device  101  may enable the receiving device  102  to acknowledge that a reset is done and the UDC buffer memory has been initialized to 0 or pre-filled by a known value. 
       FIG. 6  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. The packet format represented is for a non-limiting example of one octet (Oct 1)  600  that may be comprised in the first PDU that may be received by the transmitting device  101  in Action  501 . In the depicted example, the first PDU comprises a D/C field  601 , and the first field  602  as the PDU Type field, which may indicate the type of the PDU, as e.g., shown in Table 3. The first octet  600  of the first PDU also comprises the E/D field  603 , and the second field  604  of the first PDU as an A/D field, as e.g., shown in Table 1. Lastly, two reserved fields, a first reserved (R) field  605  and a second R field  606  are also comprised. Above the Octet,  FIG. 6  depicts the bits consumed by each field in the octet. The suspensive points in the Figure indicate certain information useful to covey the UDC information. 
       FIG. 7  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. The packet format represented is for a non-limiting example of a first octet (Oct 1)  700  that may be comprised in the first PDU that may be received by the transmitting device  101  in Action  501 . In the depicted example, the first PDU comprises the same fields described in  FIG. 6 , with the exception that there is a further second field  705 , which is an “L” field  705  replacing the first R field and indicating the Normal Operation/Temporary Deactivation state, as e.g., shown in Table 2. 
       FIG. 8  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. The packet format represented is for a non-limiting example of a first octet (Oct 1)  800  that may be comprised in the control PDU that may be sent by the transmitting device  101  in Action  502 . In the depicted example, the control PDU comprises the D/C field  801 , and the second indication in the third field  802  as the PDU Type field, which may indicate the type of the PDU, as e.g., shown in Table 3. The first octet  600  of the control PDU also comprises a further second indication in the fourth field  803  of the control PDU as the E/D field, as e.g., shown in Table 4. Lastly, three reserved fields, a first reserved (R) field  804 , a second R filed  805  and a third R field  806  are also comprised. 
       FIG. 9  is a schematic diagram illustrating an example of a packet format, according to embodiments herein. The packet format represented is for a non-limiting example of a first octet (Oct 1)  900  that may be comprised in the second PDU that is received by the transmitting device  101  in Action  503 . In the depicted example, the second PDU comprises the D/C field  601 , the first field as the PDU Type field  602 , the E/D field  603 , and the second field of the first PDU as the A/D field  604 , the further second field, as the “L” field  705 , and the fifth field as the RE field  906 . 
     Embodiments of a method, performed by the receiving device  102 , will now be described with reference to the flowchart depicted in  FIG. 10 . The method may be considered to be handling uplink data compression. The receiving device  102  operates in the communications network  100 . 
     The method, performed by the receiving device  102  may comprise one or more of the following actions. In some embodiments all the actions may be performed. In some embodiments, one or more actions may be performed. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. In  FIG. 10 , optional actions are indicated with dashed lines. Some actions may be performed in a different order than that shown in  FIG. 10 . 
     The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the transmitting device  101 , and will thus not be repeated here to simplify the description, however, it may be understood to equally apply. For example, the uplink data compression feature may be e.g., UDC in LTE. 
     Action  1001   
     In this Action  1001 , the receiving device  102  may send the first indication to the transmitting device  101 . The first indication may indicate the preference to the transmitting device  101  to activate or deactivate the uplink data compression feature. 
     The sending in this Action  1001  may be performed via the link  140 . 
     As explained earlier, the first indication may be at least one of: a) the first value in the first field  602  of the first PDU, the first field  602  indicating a type of the PDU, and b) the second value in the second field  604  of the first PDU. The second field  604 ,  705  indicating at least one of: a) the Activate/Deactivate (A/D) state, and b) the Normal Operation/Temporary Deactivation state. 
     As an example of the second field, the first indication may be a PDCP message that may be sent from the receiving device  102 , e.g., an eNB, to the transmitting device  101 , e.g., a UE, to indicate whether UDC is to be activated or deactivated by the transmitting device  101 . Table 1 shows an example of how this first indication may be defined. The second field  604  may be e.g., the “A/D” field depicted in any of  FIG. 6 ,  FIG. 7  and  FIG. 9 . 
     An alternative approach may be that the first indication does not have an explicit indication of whether the transmitting device  101  is to activate/enable or deactivate/disable UDC, but rather the reception of the first indication itself may be an implicit indication that the transmitting device  101  is to switch state, for example, disable/deactivate UDC if UDC currently is enabled/active, and enable/activate UDC if UDC currently is disabled/deactivated. This implicit indication may be that the receiving device  102  may send a PDU of a certain type, that is, with a certain value of the field “PDU type” as shown in Table 3, which may be considered an example of the first field  602 . The first field  602  may be e.g., the “PDU Type” field depicted in any of  FIG. 6 ,  FIG. 7  and  FIG. 9 . The first value may be 1 bit. The first value may be 0 or 1. 
     In some embodiments, the first indication may indicate the instruction to the transmitting device  101  to activate or deactivate the uplink data compression feature. 
     By sending the first indication to the transmitting device  101  in this Action  1001 , the receiving device  102  may exert network control on the UDC activation in the transmitting device  101 . 
     Action  1002   
     In this Action  1002 , the receiving device  102  may receive the second indication, from the transmitting device  101 . The second indication may be comprised in the control PDU. The second indication may indicate one of: a) the data compression feature is enabled in the transmitting device  101  and the header comprising the information about the enabled uplink data compression feature of one or more data PDUs is to be present in the one or more data PDUs to be received from the transmitting device  101  after receiving the indication, and b) the uplink data compression feature is disabled in the transmitting device  101  and the header comprising the information about the enabled uplink data compression feature of one or more data PDUs is to be absent in the one or more data PDUs to be received from the transmitting device  101  after receiving the indication. 
     The receiving  1002  may be performed e.g., via the link  140 . 
     As mentioned earlier, the header may be e.g., the header depicted in  FIG. 2 , in Octate 3 (Oct 3). 
     In some embodiments, as described earlier, the second indication may be one of: a) the third value in the third field  802  of the control PDU, the third field  802  indicating the type of PDU, and b) the fourth value in the fourth field  803  of the control PDU, the fourth field  803  indicating the Enabled/Disabled (E/D) state. 
     The third field  802  may be e.g., the “PDU Type” field depicted in  FIG. 8 . The third value may be 3 bit. The third value may be 011. 
     The fourth field  803  may be e.g., the “E/D” field depicted in  FIG. 8 . The fourth value may be 1 bit. The fourth value may be 0 or 1. 
     As discussed earlier, in some situations, packets received by the receiving device  102  may not be in the same order as the transmitting device  101  may have generated them. To solve this, the transmitting device  101  may, according to some embodiments, indicate a sequence number to the receiving device  102 . The sequence number may indicate which is the last packet before the switch happened, or it may indicate the first packet after the switch. Accordingly, in some embodiments, the second indication may further indicate one of: a) the sequence number of the last packet sent by the transmitting device  101  before the enabled or disabled state of the transmitting device  101  switched; and b) the sequence number of the first packet sent by the transmitting device  101  after the enabled or disabled state of the transmitting device  101  switched. 
     The receiving device  102  may then need to buffer packets received by the transmitting device  101  to mitigate or avoid that a certain packet received by the receiving device  102  is interpreted as it was generated and/or transmitted by the transmitting device  101  before the switch, while it actually was generated and/or transmitted after the switch. To do such buffering may generate additional delay since the packets may not be processed by the receiving device  102  directly upon reception from the transmitting device  101 , and hence the receiving device  102  may perform such buffering only at a time close to a switch. 
     Action  1003   
     In existing methods, it has been described to use RRC signalling to reset the buffer when failure such as checksum failures may be detected. However, an effective means to convey this may be by the receiving device  102  perform Action  103  according to embodiments herein. In this Action  1003 , the receiving device  102  sends the third indication to the transmitting device  101  operating in the communications network  100 . The third indication instructs the transmitting device  101  to perform the buffer reset. The third indication is the fifth value in the fifth field  906  in the second PDU that is sent to the transmitting device  101 . 
     As stated earlier, the third indication sent in this Action  1003  may be simply referred to herein as “the indication”. The fifth field in this Action  1003  may be simply referred to herein as “the field”, and the second PDU may be referred to herein as “the PDU”. The PDU may be a PDCP control PDU. The sending in this Action  1003  may be performed via the link  140 . 
     A particularly effective means to convey that the transmitting buffer  101  is to reset the buffer may be by the use of PDCP control PDU packet as shown in  FIG. 9 . According to embodiments herein, one of the bits as part of the newly defined PDCP control PDU packet may be used by the receiving device  102  to inform the transmitting device  101  that a reset of buffer is needed, as shown in Table 6. The fifth field  906  may be e.g., the “RE” field depicted in  FIG. 9 . The fifth value may be 1 bit. The fifth value may be 0 or 1. 
     By sending the third indication to the transmitting device  101  in this Action  1003 , the receiving device  102  may convey a buffer reset from the network to the transmitting device  101  and thereby indicate that the receiving device  102  has discovered an error during the packet decompression. This may be understood to indicate that most likely the receiving device  102  and the transmitting device  101  have mismatch in the UDC buffer memory content. 
     Action  1004   
     In this Action  1004 , the receiving device  102  may receive the fourth indication from the transmitting device  101 . The fourth indication may indicate that a buffer reset has been performed. 
     The receiving in this Action  1004  may be performed via the link  140 . 
     As stated earlier, the bit from the receiving device  102  to the transmitting device  101  may be used to convey that reset has been performed, as shown in Table 7. 
     Certain embodiments may provide one or more of the following technical advantage(s). The advantages of the embodiments herein are mainly in terms of efficiency and flexibility, which may be summarized as follows: a receiving device such as an eNB may be enabled to know if the transmitting device, e.g., a UE, has successfully released the uplink data compression feature configuration, e.g., the UDC configuration. By the transmitting device sending the second indication to the receiving device, indicating whether the uplink data compression features is enabled or disabled and whether the header is going to be present or absent in the one or more data PDUs to be sent by the transmitting device after sending the indication, the transmitting device enables the receiving device to know how to read the one or more data PDUs, and to know if the one or more data PDUs are compressed or not. Therefore, the receiving device may process the one or more data PDUs accordingly. Consequently, processing and energy resources in the communications network may be used more efficiently. 
     In addition, by the transmitting device  101  receiving the third indication, the transmitting device  101  is enabled to later reset the buffer and correct any lack of synchronization between the compression buffer and the decompression buffer, on the side of the transmitting device  101 . Consequently, the transmitting device  101  and receiving device  102  may use the UDC again. 
       FIG. 11  depicts two different examples in panels a) and b), respectively, of the arrangement that the transmitting device  101  may comprise to perform the method actions described above in relation to  FIG. 5 . In some embodiments, the transmitting device  101  may comprise the following arrangement depicted in  FIG. 11 a   . The transmitting device  101  may be configured to handle uplink data compression. The transmitting device  101  is configured to operate in the communications network  100 . 
     Several embodiments are comprised herein. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the transmitting device  101 , and will thus not be repeated here. For example, the uplink data compression feature may be e.g., UDC in LTE. 
     In  FIG. 11 , optional circuits are indicated with dashed boxes. 
     The transmitting device  101  is configured to perform the receiving of Action  503 , e.g. by means of a receiving circuit  1101  within the transmitting device  101 , configured to, receive the indication, from the receiving device  102  configured to operate in the communications network  100 . The indication is configured to instruct the transmitting device  101  to perform the buffer reset. The indication is configured to be the value in the field  906  in the PDU configured to be received from the receiving device  102 . The receiving circuit  1102  may be the processor  1105  of the transmitting device  101 , or an application running on such processor. 
     In the preceding paragraph, the indication may be understood to be the third indication, the field may be understood to be the fifth field, and the PDU may be understood to be the second PDU. The PDU may be a PDCP control PDU. 
     The transmitting device  101  is further configured to perform the resetting of Action  503 , e.g. by means of a resetting circuit  1102  within the transmitting device  101 , configured to, reset the buffer, based on the indication, that is, the third indication, configured to be received. The resetting circuit  1102  may be the processor  1105  of the transmitting device  101 , or an application running on such processor. 
     In some embodiments, the indication may be configured to be the third indication. In some of such embodiments, the transmitting device  101  may be further configured to perform the receiving of Action  501 , e.g. by means of the receiving circuit  1101  within the transmitting device  101 , configured to receive the first indication from the receiving device  102 . The first indication may be configured to indicate the preference to the transmitting device  101  to activate or deactivate the uplink data compression feature. 
     In some embodiments wherein the PDU may be configured to be the second PDU, the first indication may be configured to be at least one of: a) the first value in the first field  602  of the first PDU. The first field  602  may be configured to indicate the type of the PDU; and b) the second value in the second field  604 ,  705  of the first PDU. The second field  604 ,  705  may be configured to indicate at least one of: a) the A/D state, and b) the Normal Operation/Temporary Deactivation state. 
     In some embodiments, the indication may be configured to be the third indication. In some of such embodiments, the transmitting device  101  may be further configured to perform the sending of Action  502 , e.g. by means of a sending circuit  1103  within the transmitting device  101 , configured to, send the second indication to the receiving device  102 . The second indication is configured to be comprised in a control PDU. The second indication is configured to indicate one of: a) the uplink data compression feature is enabled in the transmitting device  101  and the header comprising information about the enabled uplink data compression feature of one or more data PDUs is to be present in the one or more data PDUs configured to be sent by the transmitting device  101  after sending the second indication; and b) the uplink data compression feature is disabled in the transmitting device  101  and the header comprising information about the enabled uplink data compression feature of one or more data PDUs is to be absent in the one or more data PDUs configured to be to be sent by the transmitting device  101  after sending the second indication. The sending circuit  1103  may be a processor  1105  of the transmitting device  101 , or an application running on such processor. 
     In some embodiments, the second indication may be configured to be one of: a) the third value in the third field  802  of the control PDU, the third field  802  being configured to indicate the type of PDU, and b) the fourth value in the fourth field  803  of the control PDU. The fourth field  803  may configured to indicate the Enabled/Disabled (E/D) state. 
     In some embodiments, the second indication may be further configured to indicate one of: a) the sequence number of the last packet configured to be sent by the transmitting device  101  before the enabled or disabled state of the transmitting device  101  is configured to be switched; and b) the sequence number of the first packet configured to be sent by the transmitting device  101  after the enabled or disabled state of the transmitting device  101  is configured to be switched. 
     In some embodiments, the indication may be configured to be the third indication. In some of such embodiments, the transmitting device  101  may be further configured to perform the sending  505  action, e.g. by means of the sending circuit  1103  within the transmitting device  101 , configured to send the fourth indication to the receiving device  102 . The fourth indication may be configured to indicate that the buffer reset has been performed. 
     Other circuits  1104  may be comprised in the transmitting device  101 . 
     The embodiments herein in the transmitting device  101  may be implemented through one or more processors, such as a processor  1105  in the transmitting device  101  depicted in  FIG. 11 a   , together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the transmitting device  101 . One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the transmitting device  101 . 
     The transmitting device  101  may further comprise a memory  1106  comprising one or more memory units. The memory  1106  is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the transmitting device  101 . 
     In some embodiments, the transmitting device  101  may receive information from, e.g., the receiving device  102 , through a receiving port  1107 . In some embodiments, the receiving port  1107  may be, for example, connected to one or more antennas in transmitting device  101 . In other embodiments, the transmitting device  101  may receive information from another structure in the communications network  100  through the receiving port  1107 . Since the receiving port  1107  may be in communication with the processor  1105 , the receiving port  1107  may then send the received information to the processor  1105 . The receiving port  1107  may also be configured to receive other information. 
     The processor  1105  in the transmitting device  101  may be further configured to transmit or send information to e.g., the receiving device  102 , another structure in the communications network  100 , through a sending port  1108 , which may be in communication with the processor  1105 , and the memory  1106 . 
     Those skilled in the art will also appreciate that the receiving circuit  1101 , the resetting circuit  1102 , the sending circuit  1103 , and the other circuits  1104  described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor  1105 , perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC). 
     Also, in some embodiments, the different modules or circuits  1101 - 1104  described above may be implemented as one or more applications running on one or more processors such as the processor  1105 . 
     Thus, the methods according to the embodiments described herein for the transmitting device  101  may be respectively implemented by means of a computer program  1109  product, comprising instructions, i.e., software code portions, which, when executed on at least one processor  1105 , cause the at least one processor  1105  to carry out the actions described herein, as performed by the transmitting device  101 . The computer program  1109  product may be stored on a computer-readable storage medium  1110 . The computer-readable storage medium  1110 , having stored thereon the computer program  1109 , may comprise instructions which, when executed on at least one processor  1105 , cause the at least one processor  1105  to carry out the actions described herein, as performed by the transmitting device  101 . In some embodiments, the computer-readable storage medium  1110  may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program  1109  product may be stored on a carrier containing the computer program  1109  just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium  1110 , as described above. 
     The transmitting device  101  may comprise a communication interface configured to facilitate communications between the transmitting device  101  and other nodes or devices, e.g., the receiving device  102 . The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard. 
     In other embodiments, the transmitting device  101  may comprise the following arrangement depicted in  FIG. 11 b   . The transmitting device  101  may comprise a processing circuitry  1105 , e.g., one or more processors such as the processor  1105 , in the transmitting device  101  and the memory  1106 . The transmitting device  101  may also comprise a radio circuitry  1111 , which may comprise e.g., the receiving port  1107  and the sending port  1108 . The processing circuitry  1105  may be configured to, or operable to, perform the method actions according to  FIG. 5 , and/or  FIGS. 16-20 , in a similar manner as that described in relation to  FIG. 11 a   . The radio circuitry  1111  may be configured to set up and maintain at least a wireless connection with the receiving device  102 . Circuitry may be understood herein as a hardware component. 
     Hence, embodiments herein also relate to the transmitting device  101  operative to operate in the communications network  100 . The transmitting device  101  may comprise the processing circuitry  1105  and the memory  1106 , said memory  1106  containing instructions executable by said processing circuitry  1105 , whereby the transmitting device  101  is further operative to perform the actions described herein in relation to the transmitting device  101 , e.g., in  FIG. 5 , and/or  FIGS. 16-20 . 
       FIG. 12  depicts two different examples in panels a) and b), respectively, of the arrangement that the receiving device  102  may comprise to perform the method actions described above in relation to  FIG. 10 . In some embodiments, the receiving device  102  may comprise the following arrangement depicted in  FIG. 12 a   . The receiving device  102  may be configured to handle uplink data compression. The receiving device  102  is configured to operate in the communications network  100 . 
     Several embodiments are comprised herein. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the receiving device  102 , and will thus not be repeated here. For example, the uplink data compression feature may be e.g., UDC in LTE. 
     In  FIG. 12 , optional circuits are indicated with dashed boxes. 
     The receiving device  102  is further configured to perform the sending of Action  1003 , e.g. by means of a sending circuit  1201  within the receiving device  102 , configured to, send the indication to the transmitting device  101  configured to operate in the communications network  100 . The indication is configured to instruct the transmitting device  101  to perform the buffer reset. The indication is configured to be the value in the field  906  in the PDU configured to be sent to the transmitting device  101 . The sending circuit  1201  may be the processor  1204  of the receiving device  102 , or an application running on such processor. 
     In the preceding paragraph, the indication may be understood to be the third indication, the field may be understood to be the fifth field, and the PDU may be understood to be the second PDU. The PDU may be a PDCP control PDU. 
     In some of such embodiments, the indication may be configured to be the third indication. In some of such embodiments, the receiving device  102  may be further configured to perform the sending of Action  1001 , e.g. by means of the sending circuit  1201  within the receiving device  102 , configured to send the first indication to the transmitting device  101 . The first indication may be configured to indicate the preference to the transmitting device  101  to activate or deactivate the uplink data compression feature. 
     In some embodiments, PDU may be configured to be the second PDU. In some of such embodiments, the first indication may be configured to be at least one of: a) the first value in the first field  602  of the first PDU. The first field  602  may be configured to indicate the type of the PDU; and b) the second value in the second field  604 ,  705  of the first PDU. The second field  604 ,  705  may be configured to indicate at least one of: a) the A/D state, and b) the Normal Operation/Temporary Deactivation state. 
     In some embodiments, the indication may be configured to be the third indication. In some of such embodiments, the receiving device  102  may be configured to perform the receiving of Action  1002 , e.g. by means of the receiving circuit  1201  within the receiving device  102 , configured to, receive the second indication from the transmitting device  101  configured to operate in the communications network  100 . The second indication is configured to be comprised in a control PDU. The second indication is configured to indicate one of: a) the uplink data compression feature is enabled in the transmitting device  101  and the header comprising information about the enabled uplink data compression feature of one or more data PDUs is to be present in the one or more data PDUs configured to be received from the transmitting device  101  after receiving the second indication, and b) the uplink data compression feature is disabled in the transmitting device  101  and the header comprising information about the enabled uplink data compression feature of one or more data PDUs is to be absent in the one or more data PDUs configured to be received from the transmitting device  101  after receiving the second indication. The receiving circuit  1201  may be a processor  1204  of the receiving device  102 , or an application running on such processor. 
     In some embodiments, the second indication may be configured to be one of: a) the third value in the third field  802  of the control PDU, the third field  802  being configured to indicate the type of PDU, and b) the fourth value in the fourth field  803  of the control PDU. The fourth field  803  may be configured to indicate the Enabled/Disabled (E/D) state. 
     In some embodiments, the second indication may be further configured to indicate one of: a) the sequence number of the last packet configured to be sent by the transmitting device  101  before the enabled or disabled state of the transmitting device  101  is configured to be switched; and b) the sequence number of the first packet configured to be sent by the transmitting device  101  after the enabled or disabled state of the transmitting device  101  is configured to be switched. 
     In some embodiments, the indication may be configured to be the third indication. In some of such embodiments, the receiving device  102  may be further configured to perform the receiving of Action  1004 , e.g. by means of a receiving circuit  1202  within the receiving device  102 , configured to, receive the fourth indication from the transmitting device  101 . The fourth indication may be configured to indicate that the buffer reset has been performed. The receiving circuit  1202  may be the processor  1204  of the receiving device  102 , or an application running on such processor. 
     Other circuits  1203  may be comprised in the receiving device  102 . 
     The embodiments herein in the receiving device  102  may be implemented through one or more processors, such as a processor  1204  in the receiving device  102  depicted in  FIG. 12 a   , together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the receiving device  102 . One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the receiving device  102 . 
     The receiving device  102  may further comprise a memory  1205  comprising one or more memory units. The memory  1205  is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the receiving device  102 . 
     In some embodiments, the receiving device  102  may receive information from, e.g., the transmitting device  101 , through a receiving port  1206 . In some embodiments, the receiving port  1206  may be, for example, connected to one or more antennas in receiving device  102 . In other embodiments, the receiving device  102  may receive information from another structure in the communications network  100  through the receiving port  1206 . Since the receiving port  1206  may be in communication with the processor  1204 , the receiving port  1206  may then send the received information to the processor  1204 . The receiving port  1206  may also be configured to receive other information. 
     The processor  1204  in the receiving device  102  may be further configured to transmit or send information to e.g., the transmitting device  101 , or another structure in the communications network  100 , through a sending port  1207 , which may be in communication with the processor  1204 , and the memory  1205 . 
     Those skilled in the art will also appreciate that the sending circuit  1201 , the receiving circuit  1202 , and the other circuits  1203  described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor  1204 , perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC). 
     Also, in some embodiments, the different circuits  1201 - 1203  described above may be implemented as one or more applications running on one or more processors such as the processor  1204 . 
     Thus, the methods according to the embodiments described herein for the receiving device  102  may be respectively implemented by means of a computer program  1208  product, comprising instructions, i.e., software code portions, which, when executed on at least one processor  1204 , cause the at least one processor  1204  to carry out the actions described herein, as performed by the receiving device  102 . The computer program  1208  product may be stored on a computer-readable storage medium  1209 . The computer-readable storage medium  1209 , having stored thereon the computer program  1208 , may comprise instructions which, when executed on at least one processor  1204 , cause the at least one processor  1204  to carry out the actions described herein, as performed by the receiving device  102 . In some embodiments, the computer-readable storage medium  1209  may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program  1208  product may be stored on a carrier containing the computer program  1208  just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium  1209 , as described above. 
     The receiving device  102  may comprise a communication interface configured to facilitate communications between the receiving device  102  and other nodes or devices, e.g., the transmitting device  101 . The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard. 
     In other embodiments, the receiving device  102  may comprise the following arrangement depicted in  FIG. 12 b   . The receiving device  102  may comprise a processing circuitry  1204 , e.g., one or more processors such as the processor  1204 , in the receiving device  102  and the memory  1205 . The receiving device  102  may also comprise a radio circuitry  1210 , which may comprise e.g., the receiving port  1206  and the sending port  1207 . The processing circuitry  1210  may be configured to, or operable to, perform the method actions according to  FIG. 10 , and/or  FIG. 16-20 , in a similar manner as that described in relation to  FIG. 12 a   . The radio circuitry  1210  may be configured to set up and maintain at least a wireless connection with the transmitting device  101 . Circuitry may be understood herein as a hardware component. 
     Hence, embodiments herein also relate to the receiving device  102  operative to operate in the communications network  100 . The receiving device  102  may comprise the processing circuitry  1204  and the memory  1205 , said memory  1205  containing instructions executable by said processing circuitry  1204 , whereby the receiving device  102  is further operative to perform the actions described herein in relation to the receiving device  102 , e.g., in  FIG. 10 , and/or  FIG. 16-20 . 
     As used herein, the expression “at least one of:” followed by a list of alternatives separated by commas, and wherein the last alternative is preceded by the “and” term, may be understood to mean that only one of the list of alternatives may apply, more than one of the list of alternatives may apply or all of the list of alternatives may apply. This expression may be understood to be equivalent to the expression “at least one of:” followed by a list of alternatives separated by commas, and wherein the last alternative is preceded by the “or” term. 
     Further Examples Related to Embodiments Herein 
     In examples related to embodiments herein, the method, performed by the transmitting device  101  may comprise one or more of the actions described in relation to  FIG. 5 . In some examples, all the actions may be performed. In some examples, one or more actions may be performed. One or more examples may be combined, where applicable. All possible combinations are not described to simplify the description.  FIG. 13 , for example, depicts an example of a method related to embodiments herein, wherein the transmitting device  101  may perform Action  502 , alone, or in combination with one or more of Action  501 , Action  503 , Action  504 , and/or Action  505 . In  FIG. 13 , optional actions are indicated with dashed lines. Some actions may be performed in a different order than that shown in  FIG. 13 . The method of the example of  FIG. 13  related to embodiments herein, may also be performed by the transmitting device  101 , similarly to how it was described in  FIG. 11 . 
     In other examples related to embodiments herein, the method, performed by the receiving device  102  may comprise one or more of the actions described in relation to  FIG. 10 . In some examples, all the actions may be performed. In some examples, one or more actions may be performed. One or more examples may be combined, where applicable. All possible combinations are not described to simplify the description.  FIG. 14 , for example, depicts an example of a method related to embodiments herein, wherein the receiving device  102  may perform Action  1002  alone, or in combination with one or more of Action  1001 , Action  1003 , and/or Action  1004 . In  FIG. 14 , optional actions are indicated with dashed lines. Some actions may be performed in a different order than that shown in  FIG. 14 . The method of the example of  FIG. 14  related to embodiments herein, may also be performed by the receiving device  102 , similarly to how it was described in  FIG. 12 . 
     Further Extensions And Variations 
       FIG. 15 : Telecommunication Network Connected Via an Intermediate Network to a Host Computer in Accordance with Some Embodiments 
     With reference to  FIG. 15 , in accordance with an embodiment, a communication system includes telecommunication network  1510  such as the communications network  100 , for example, a 3GPP-type cellular network, which comprises access network  1511 , such as a radio access network, and core network  1514 . Access network  1511  comprises a plurality of network nodes such as the network node  110 . For example, base stations  1512   a ,  1512   b ,  1512   c , such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area  1513   a ,  1513   b ,  1513   c . Each base station  1512   a ,  1512   b ,  1512   c  is connectable to core network  1514  over a wired or wireless connection  1515 . A plurality of wireless devices, such as the wireless device  120  are comprised in the communications network  100 . In  FIG. 15 , a first UE  1591  located in coverage area  1513   c  is configured to wirelessly connect to, or be paged by, the corresponding base station  1512   c . A second UE  1592  in coverage area  1513   a  is wirelessly connectable to the corresponding base station  1512   a . While a plurality of UEs  1591 ,  1592  are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station  1512 . Any of the UEs  1591 ,  1592  are examples of the wireless device  120 . 
     Telecommunication network  1510  is itself connected to host computer  1530 , which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer  1530  may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections  1521  and  1522  between telecommunication network  1510  and host computer  1530  may extend directly from core network  1514  to host computer  1530  or may go via an optional intermediate network  1520 . Intermediate network  1520  may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network  1520 , if any, may be a backbone network or the Internet; in particular, intermediate network  1520  may comprise two or more sub-networks (not shown). 
     The communication system of  FIG. 15  as a whole enables connectivity between the connected UEs  1591 ,  1592  and host computer  1530 . The connectivity may be described as an over-the-top (OTT) connection  1550 . Host computer  1530  and the connected UEs  1591 ,  1592  are configured to communicate data and/or signaling via OTT connection  1550 , using access network  1511 , core network  1514 , any intermediate network  1520  and possible further infrastructure (not shown) as intermediaries. OTT connection  1550  may be transparent in the sense that the participating communication devices through which OTT connection  1550  passes are unaware of routing of uplink and downlink communications. For example, base station  1512  may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer  1530  to be forwarded (e.g., handed over) to a connected UE  1591 . Similarly, base station  1512  need not be aware of the future routing of an outgoing uplink communication originating from the UE  1591  towards the host computer  1530 . 
     In relation to  FIGS. 16, 17, 18, 19, and 20 , which are described next, it may be understood that a UE is an example of the transmitting device  101 , and that any description provided for the UE equally applies to the transmitting device  101 . It may be also understood that the base station is an example of the receiving device  102 , and that any description provided for the base station equally applies to the receiving device  102 . 
       FIG. 16 : Host Computer Communicating Via a Base Station with a User Equipment Over a Partially Wireless Connection in Accordance with Some Embodiments 
     Example implementations, in accordance with an embodiment, of the transmitting device  101 , e.g., a UE, the receiving device  102 , e.g., a base station and host computer discussed in the preceding paragraphs will now be described with reference to  FIG. 16 . In communication system  1600 , such as the communications network  100 , host computer  1610  comprises hardware  1615  including communication interface  1616  configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system  1600 . Host computer  1610  further comprises processing circuitry  1618 , which may have storage and/or processing capabilities. In particular, processing circuitry  1618  may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer  1610  further comprises software  1611 , which is stored in or accessible by host computer  1610  and executable by processing circuitry  1618 . Software  1611  includes host application  1612 . Host application  1612  may be operable to provide a service to a remote user, such as UE  1630  connecting via OTT connection  1650  terminating at UE  1630  and host computer  1610 . In providing the service to the remote user, host application  1612  may provide user data which is transmitted using OTT connection  1650 . 
     Communication system  1600  further includes the receiving device  102 , exemplified in  FIG. 16  as a base station  1620  provided in a telecommunication system and comprising hardware  1625  enabling it to communicate with host computer  1610  and with UE  1630 . Hardware  1625  may include communication interface  1626  for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system  1600 , as well as radio interface  1627  for setting up and maintaining at least wireless connection  1670  with the transmitting device  101 , exemplified in  FIG. 16  as a UE  1630  located in a coverage area (not shown in  FIG. 16 ) served by base station  1620 . Communication interface  1626  may be configured to facilitate connection  1660  to host computer  1610 . Connection  1660  may be direct or it may pass through a core network (not shown in  FIG. 16 ) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware  1625  of base station  1620  further includes processing circuitry  1628 , which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station  1620  further has software  1621  stored internally or accessible via an external connection. 
     Communication system  1600  further includes UE  1630  already referred to. Its hardware  1635  may include radio interface  1637  configured to set up and maintain wireless connection  1670  with a base station serving a coverage area in which UE  1630  is currently located. Hardware  1635  of UE  1630  further includes processing circuitry  1638 , which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE  1630  further comprises software  1631 , which is stored in or accessible by UE  1630  and executable by processing circuitry  1638 . Software  1631  includes client application  1632 . Client application  1632  may be operable to provide a service to a human or non-human user via UE  1630 , with the support of host computer  1610 . In host computer  1610 , an executing host application  1612  may communicate with the executing client application  1632  via OTT connection  1650  terminating at UE  1630  and host computer  1610 . In providing the service to the user, client application  1632  may receive request data from host application  1612  and provide user data in response to the request data. OTT connection  1650  may transfer both the request data and the user data. Client application  1632  may interact with the user to generate the user data that it provides. 
     It is noted that host computer  1610 , base station  1620  and UE  1630  illustrated in  FIG. 16  may be similar or identical to host computer  1530 , one of base stations  1512   a ,  1512   b ,  1512   c  and one of UEs  1591 ,  1592  of  FIG. 15 , respectively. This is to say, the inner workings of these entities may be as shown in  FIG. 16  and independently, the surrounding network topology may be that of  FIG. 15 . 
     In  FIG. 16 , OTT connection  1650  has been drawn abstractly to illustrate the communication between host computer  1610  and UE  1630  via base station  1620 , without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE  1630  or from the service provider operating host computer  1610 , or both. While OTT connection  1650  is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network). 
     Wireless connection  1670  between UE  1630  and base station  1620  is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE  1630  using OTT connection  1650 , in which wireless connection  1670  forms the last segment. More precisely, the teachings of these embodiments may improve the latency, signalling overhead, and service interruption and thereby provide benefits such as reduced user waiting time, better responsiveness and extended battery lifetime. 
     A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection  1650  between host computer  1610  and UE  1630 , in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection  1650  may be implemented in software  1611  and hardware  1615  of host computer  1610  or in software  1631  and hardware  1635  of UE  1630 , or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection  1650  passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software  1611 ,  1631  may compute or estimate the monitored quantities. The reconfiguring of OTT connection  1650  may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station  1620 , and it may be unknown or imperceptible to base station  1620 . Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer  1610 &#39;s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software  1611  and  1631  causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection  1650  while it monitors propagation times, errors etc. 
     The transmitting device  101  may comprise an arrangement as shown in  FIG. 11  or in  FIG. 16 . 
     The transmitting device  101  may also comprise a client application  1632  or a client application circuit, which may be configured to communicate user data with a host application circuit in a host computer  1610 , e.g., via another link such as  1650 . 
     The transmitting device  101  may comprise an interface unit to facilitate communications between the transmitting device  101  and other nodes or devices, e.g., the receiving device  102 , the host computer  1610 , or any of the other nodes. In some particular examples, the interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard. 
     The receiving device  102  may comprise an arrangement as shown in  FIG. 12  or in  FIG. 16 . 
     The receiving device  102  may also comprise a communication interface  1626  and/or a radio interface  1627 , which may be configured to communicate user data with a host application circuit in a host computer  1610 , e.g., via another link such as  1650 . 
     The receiving device  102  may comprise an interface unit to facilitate communications between the receiving device  102  and other nodes or devices, e.g., the receiving device  102 , the host computer  1610 , or any of the other nodes. In some particular examples, the interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard. 
       FIG. 17 : Methods Implemented in a Communication System Including a Host Computer, a Base Station and a User Equipment in Accordance with Some Embodiments 
       FIG. 17  is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS. 15 and 16 . For simplicity of the present disclosure, only drawing references to  FIG. 17  will be included in this section. In step  1710 , the host computer provides user data. In substep  1711  (which may be optional) of step  1710 , the host computer provides the user data by executing a host application. In step  1720 , the host computer initiates a transmission carrying the user data to the UE. In step  1730  (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step  1740  (which may also be optional), the UE executes a client application associated with the host application executed by the host computer. 
       FIG. 18 : Methods Implemented in a Communication System Including a Host Computer, a Base Station and a User Equipment in Accordance with Some Embodiments 
       FIG. 18  is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS. 15 and 16 . For simplicity of the present disclosure, only drawing references to  FIG. 18  will be included in this section. In step  1810  of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step  1820 , the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step  1830  (which may be optional), the UE receives the user data carried in the transmission. 
       FIG. 19 : Methods Implemented in a Communication System Including a Host Computer, a Base Station and a User Equipment in Accordance with Some Embodiments 
       FIG. 19  is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS. 15 and 16 . For simplicity of the present disclosure, only drawing references to  FIG. 19  will be included in this section. In step  1910  (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step  1920 , the UE provides user data. In substep  1921  (which may be optional) of step  1920 , the UE provides the user data by executing a client application. In substep  1911  (which may be optional) of step  1910 , the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep  1930  (which may be optional), transmission of the user data to the host computer. In step  1940  of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure. 
       FIG. 20 : Methods Implemented in a Communication System Including a Host Computer, a Base Station and a User Equipment in Accordance with Some Embodiments 
       FIG. 20  is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS. 15 and 16 . For simplicity of the present disclosure, only drawing references to  FIG. 20  will be included in this section. In step  2010  (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step  2020  (which may be optional), the base station initiates transmission of the received user data to the host computer. In step  2030  (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. 
     The transmitting device  101  embodiments relate to  FIG. 5 ,  FIG. 6 ,  FIG. 7 ,  FIG. 8 ,  FIG. 9 ,  FIG. 11 , and  FIGS. 16-20 . 
     The receiving device  102  embodiments relate to  FIG. 6 ,  FIG. 7 ,  FIG. 8 ,  FIG. 9 ,  FIG. 10 ,  FIG. 12 , and  FIGS. 16-20 . 
     Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure. 
     The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein. 
     Further Numbered Embodiments 
     The communications system embodiments relate to  FIGS. 15-20 . 
     The communications system  1600  may comprise the host computer  1611 , and at least one of the receiving device  102 , and the transmitting device  101 .
     1. A base station configured to communicate with a user equipment (UE), the base station comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the receiving device  102 .   5. A communication system including a host computer comprising:
       processing circuitry configured to provide user data; and   a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE),   wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the receiving device  102 .   
       6. The communication system of embodiment 5, further including the base station.   7. The communication system of embodiment 6, further including the UE, wherein the UE is configured to communicate with the base station.   8. The communication system of embodiment 7, wherein:
       the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and   the UE comprises processing circuitry configured to execute a client application associated with the host application.   
       11. A method implemented in a base station, comprising one or more of the actions described herein as performed by the receiving device  102 .   15. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:
       at the host computer, providing user data; and   at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs one or more of the actions described herein as performed by the receiving device  102 .   
       16. The method of embodiment 15, further comprising:
       at the base station, transmitting the user data.   
       17. The method of embodiment 16, wherein the user data is provided at the host computer by executing a host application, the method further comprising:
       at the UE, executing a client application associated with the host application.   
       21. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the transmitting device  101 .   25. A communication system including a host computer comprising:
       processing circuitry configured to provide user data; and   a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE),   wherein the UE comprises a radio interface and processing circuitry, the UE&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the transmitting device  101 .   
       26. The communication system of embodiment 25, further including the UE.   27. The communication system of embodiment 26, wherein the cellular network further includes a base station configured to communicate with the UE.   28. The communication system of embodiment 26 or 27, wherein:
       the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and   the UE&#39;s processing circuitry is configured to execute a client application associated with the host application.   
       31. A method implemented in a user equipment (UE), comprising one or more of the actions described herein as performed by the transmitting device  101 .   35. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:
       at the host computer, providing user data; and   at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs one or more of the actions described herein as performed by the transmitting device  101 .   
       36. The method of embodiment 35, further comprising:
       at the UE, receiving the user data from the base station.   
       41. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the transmitting device  101 .   45. A communication system including a host computer comprising:
       a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station,   wherein the UE comprises a radio interface and processing circuitry, the UE&#39;s processing circuitry configured to: perform one or more of the actions described herein as performed by the transmitting device  101 .   
       46. The communication system of embodiment 45, further including the UE.   47. The communication system of embodiment 46, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.   48. The communication system of embodiment 46 or 47, wherein:
       the processing circuitry of the host computer is configured to execute a host application; and   the UE&#39;s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.   
       49. The communication system of embodiment 46 or 47, wherein:
       the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and   the UE&#39;s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.   
       51. A method implemented in a user equipment (UE), comprising one or more of the actions described herein as performed by the transmitting device  101 .   52. The method of embodiment 51, further comprising:
       providing user data; and   forwarding the user data to a host computer via the transmission to the base station.   
       55. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:
       at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs one or more of the actions described herein as performed by the transmitting device  101 .   
       56. The method of embodiment 55, further comprising:
       at the UE, providing the user data to the base station.   
       57. The method of embodiment 56, further comprising:
       at the UE, executing a client application, thereby providing the user data to be transmitted; and   at the host computer, executing a host application associated with the client application.   
       58. The method of embodiment 56, further comprising:
       at the UE, executing a client application; and   at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application,   wherein the user data to be transmitted is provided by the client application in response to the input data.   
       61. A base station configured to communicate with a user equipment (UE), the base station comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the receiving device  102 .   65. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the receiving device  102 .   66. The communication system of embodiment 65, further including the base station.   67. The communication system of embodiment 66, further including the UE, wherein the UE is configured to communicate with the base station.   68. The communication system of embodiment 67, wherein:
       the processing circuitry of the host computer is configured to execute a host application;   the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.   
       71. A method implemented in a base station, comprising one or more of the actions described herein as performed by the receiving device  102 .   75. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:
       at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs one or more of the actions described herein as performed by the transmitting device  101 .   
       76. The method of embodiment 75, further comprising:
       at the base station, receiving the user data from the UE.   
       77. The method of embodiment 76, further comprising:
       at the base station, initiating a transmission of the received user data to the host computer.   
       

     REFERENCES 
     
         
         [1] IETF RFC 1951, “DEFLATE Compressed Data Format Specification version 1.3” 
         [2] 3gpp TS 36.323, “Evolved Universal Terrestrial Radio Access (E-UTRA); Packet Data Convergence Protocol (PDCP) specification”. 
         [3] 3gpp TR 36.754 v.0.0.2, “Study on UL data compression for E-UTRA (Release 15)” 
         [4] R2-1712070, “Running 36.323 CR for Introduction of UDC” 
         [5] RP-172076, “UL data compression in LTE” UDC WI 
       
    
     ABBREVIATIONS 
     At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).
     3GPP 3rd Generation Partnership Project   5G 5th Generation   DL Downlink   eNB E-UTRAN NodeB   E-UTRA Evolved UTRA   E-UTRAN Evolved UTRAN   GERAN GSM EDGE Radio Access Network   gNB Base station in NR   GSM Global System for Mobile communication   HSPA High Speed Packet Access   LTE Long-Term Evolution   OFDM Orthogonal Frequency Division Multiplexing   PDCP Packet Data Convergence Protocol   UE User Equipment   UL Uplink   UMTS Universal Mobile Telecommunication System   UTRA Universal Terrestrial Radio Access   UTRAN Universal Terrestrial Radio Access Network   WCDMA Wide CDMA   WLAN Wide Local Area Network   UDC Uplink Data Compression