TECHNICAL FIELD

Embodiments herein relate to a user equipment (UE), a radio network node and methods performed therein regarding wireless communication. In particular, embodiments herein relate to handling communication, such as handling, controlling and/or managing access, in a wireless communication network.

BACKGROUND

In a typical wireless communication network, user equipment (UE), also known as wireless communication devices, mobile stations, stations (STA) and/or wireless devices, communicate via a Radio Access Network (RAN) with one or more core networks (CN). The RAN covers a geographical area which is divided into service areas or cell areas, with each service area or cell area being served by a radio network node such as an access node e.g. a Wi-Fi access point or a radio base station (RBS), which in some networks may also be called, for example, a NodeB, a gNodeB, or an eNodeB. The service area or cell area is a geographical area where radio coverage is provided by the radio network node. The radio network node operates on radio frequencies to

communicate over an air interface with the UEs within range of the radio network node. The radio network node communicates over a downlink (DL) to the UE and the UE communicates over an uplink (UL) to the radio network node.

A Universal Mobile Telecommunications System (UMTS) is a third generation telecommunication network, which evolved from the second generation (2G) Global System for Mobile Communications (GSM). The UMTS terrestrial radio access network (UTRAN) is essentially a RAN using wideband code division multiple access (WCDMA) and/or High-Speed Packet Access (HSPA) for communication with user equipment. In a forum known as the Third Generation Partnership Project (3GPP), telecommunications suppliers propose and agree upon standards for present and future generation networks and UTRAN specifically, and investigate enhanced data rate and radio capacity. In some RANs, e.g. as in UMTS, several radio network nodes may be connected, e.g., by landlines or microwave, to a controller node, such as a radio network controller (RNC) or a base station controller (BSC), which supervises and coordinates various activities of the plural radio network nodes connected thereto. The RNCs are typically connected to one or more core networks.

Specifications for the Evolved Packet System (EPS) have been completed within the 3GPP and this work continues in the coming 3GPP releases, such as 4G and 5G networks such as New Radio (NR). The EPS comprises the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Long-Term Evolution (LTE) radio access network, and the Evolved Packet Core (EPC), also known as System Architecture Evolution (SAE) core network. E-UTRAN/LTE is a 3GPP radio access technology wherein the radio network nodes are directly connected to the EPC core network. As such, the Radio Access Network (RAN) of an EPS has an essentially“flat” architecture comprising radio network nodes connected directly to one or more core networks.

With the emerging 5G technologies such as new radio (NR), the use of very many transmit- and receive-antenna elements is of great interest as it makes it possible to utilize beamforming, such as transmit-side and receive-side beamforming. Transmit-side beamforming means that the transmitter can amplify the transmitted signals in a selected direction or directions, while suppressing the transmitted signals in other directions.

Similarly, on the receive-side, a receiver can amplify signals from a selected direction or directions, while suppressing unwanted signals from other directions.

In future versions of 5G, the radio interface will need to offer support for massive machine type communication (MTC) access, with potentially tens of thousands of terminals per cell, of which most are dormant and only a few are active at a given point in time. A basic physical constraint is that when there are large numbers of devices, it is impossible to allocate each one an orthogonal random-access sequence such as a pilot signal.

Three challenges for the physical-layer design with massive MTC (mMTC) are: reliable and fast user activity detection, i.e. the radio network node determines who is transmitting; decoding of small information blocks with low latency since UEs may send only a few bits; resilience against spoofing attacks since the presence of adversaries who “steal” random access or pilot sequences in order to inject false information into the network or steal access credentials may increase.

Prior art has addressed the device activity problem through the use of

sophisticated sparsity-based signal processing algorithms, see“Sparse Signal Processing for Grant-Free Massive Connectivity: A Future Paradigm for Random Access Protocols in the Internet of Things” Liang Liu et al. IEEE Signal Processing Magazine Volume: 35 , Issue: 5 , Sept. 2018. These techniques can allow large numbers of terminals to contend for access, and the base station with high probability determine which terminals that were active in a given slot, even when the number of contending terminals is so large that assignment of mutually orthogonal pilot/random access sequences is physically impossible.

Prior art has also developed methods for the embedding of short information blocks within the random-access sequences. This can be done by expanding the space of sequences, such that a random-access sequence carries both information about the user identity and a few information bits, see“Grant-Free Massive MTC-Enabled Massive MIMO: A Compressive Sensing Approach” Kamil Senel et al. IEEE Transactions on Communications Volume: 66 , Issue: 12 , Dec. 2018 . It can also, advantageously, be done by using so-called unsourced coding techniques, see“Massive MIMO Unsourced Random Access” Alexander Fengler et al. CoRR abs/1901.00828 2019. These methods enable grant-free random access on uplink, and function even in scenarios where there is no reliable downlink (or no time for conventional acknowledgement or connection establishment procedures that require downlink transmission).

Concurrently, anti-spoofing and integrated authenticated methods for mMTC have been developed. Reference“Massive machine-type communication (mMTC) access with integrated authentication” Nuno K. Pratas et al. 2017 IEEE International Conference on Communications (ICC) ISSN: 1938-1883 discloses a scheme in which the devices use random access sequences that embed authentication information (using a shared secret with the base station). The base station can then discern from uplink received data alone with high probability whether a contending user is legitimate or not, before initiating a conventional authentication scheme that involves interaction with the terminal on downlink. However, this technique addresses only the connection establishment problem, not the data transmission per se.

Methods for joint random access and short data packet transmission, as mentioned above, are highly vulnerable to spoofing attacks, where an adversary steals random access sequences that belong to legitimate terminals and transmit these sequences with high power. These sequences in turn are publicly known, which in turn enables the injection of false information into the network. Integrated authentication schemes such as document“Massive machine-type communication (mMTC) access with integrated authentication” Nuno K. Pratas et al. 2017 IEEE International Conference on Communications (ICC) ISSN: 1938-1883 do not solve this basic problem.

Another existing solution is to schedule the UE for data transmission and ask it to explicitly send a unique long user ID, -100 bit, which is nearly impossible to guess, to protect against spoofing. If this is sent along with the data bits and the number of data bits is small, compared to the length of the user ID length, most of the transmission will contain ID bits which is an inefficient solution.

SUMMARY

An object herein is to provide a mechanism to enable communication, e.g. handle or manage access to a wireless communication network, in a secure and efficient manner in the wireless communications network.

According to an aspect the object is achieved, according to embodiments herein, by providing a method performed by a UE for handling communication in a wireless communication network. The UE selects a pilot hopping sequence based on an identity of the UE and further based on an algorithm known to the radio network node and/or a time stamp of the selection, wherein selecting comprises mapping the identity, and the algorithm known to the radio network node and/or the time stamp, onto a sequence of integers; and mapping the sequence of integers onto a sequence of pilot waveforms using a pre-determined mapping. The UE then transmits the selected pilot hopping sequence to a radio network node.

According to another aspect the object is achieved, according to embodiments herein, by providing a method performed by a radio network node for handling

communication in a wireless communication network. The radio network node receives a pilot hopping sequence from a UE for access and authentication of the UE. The radio network node authenticates the UE by identifying the UE based on the received pilot hopping sequence, and wherein the pilot hopping sequence comprises a sequence of pilot waveforms mapped to a sequence of integers according to a predetermined mapping and the sequence of integers is mapped to an identity of the UE, and an algorithm known to the radio network node and/or a time stamp.

According to a further aspect the object is achieved, according to embodiments herein, by providing a UE for handling communication in a wireless communication network. The UE is configured to select pilot hopping sequence based on an identity of the UE and further based on an algorithm known to a radio network node and/or a time stamp of the selection, by being configured to map the identity, and the algorithm known to the radio network node and/or the time stamp, onto a sequence of integers, and to further map the sequence of integers onto a sequence of pilot waveforms using a pre determined mapping. The UE is further configured to transmit the selected pilot hopping sequence to the radio network node. According to yet a further aspect the object is achieved, according to embodiments herein, by providing a radio network node for handling communication in a wireless communication network. The radio network node is configured to receive a pilot hopping sequence from a UE for access and authentication of the UE. The radio network node is further configured to authenticate the UE by identifying the UE based on the received pilot hopping sequence. The pilot hopping sequence comprises a sequence of pilot waveforms mapped to a sequence of integers according to a predetermined mapping and the sequence of integers is mapped to an identity of the UE, and an algorithm known to the radio network node and/or a time stamp.

It is furthermore provided herein a computer program product comprising instructions, which, when executed on at least one processor, cause the at least one processor to carry out the method above, as performed by the UE and the radio network node, respectively. It is additionally provided herein a computer-readable storage medium, having stored thereon a computer program product comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to the method above, as performed by the UE or the radio network node, respectively.

The proposed solution comprises access and the authentication procedures and carries out these procedures at the physical layer, to achieve low delays and low overhead. The UE and the radio network node have a shared secret, i.e. the algorithm, that is utilized to select the pilot hopping sequence between pilot waveforms e.g.

reference signals such as sounding signals or random-access pre-ambles or uplink pilot sequences, etc. The UE transmits this pilot hopping sequence over a multitude of physical resources, e.g. resource blocks and/or transmission time intervals that are separated in time and frequency. The radio network node receives the pilot hopping sequence and uses it to identify the UE.

Embodiments herein provide an efficient way for activity detection of pilot sequences, which in turn facilitates“non-coherent” detection, i.e. without prior channel estimation, of many colliding orthogonal or non-orthogonal sequences enabling

communication in a secure and efficient manner in the wireless communications network.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described in more detail in relation to the enclosed drawings, in which: Fig. 1 is a schematic overview depicting a wireless communications network according to embodiments herein;

Fig. 2 is a combined signaling scheme and flowchart according to embodiments herein;

Fig. 3 is a combined signaling scheme and flowchart according to embodiments herein;

Fig. 4 is a schematic flowchart depicting a method performed by a UE according to embodiments herein;

Fig. 5 is a schematic flowchart depicting a method performed by a radio network node according to embodiments herein;

Fig. 6 is a diagram depicting probability of miss-authentication;

Fig. 7 is a flowchart depicting detection of an illegitimate UE;

Fig. 8 is a block diagram depicting a UE according to embodiments herein;

Fig. 9 is a block diagram depicting a radio network node according to

embodiments herein;

Fig. 10 is a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments;

Fig. 11 is a host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments;

Fig. 12 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments;

Fig. 13 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments;

Fig. 14 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments; and

Fig. 15 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments. DETAILED DESCRIPTION

Embodiments herein relate to wireless communication networks in general. Fig. 1 is a schematic overview depicting a wireless communication network 1. The wireless communications network 1 comprises one or more RANs and one or more CNs. The wireless communications network 1 may use one or a number of different technologies. Embodiments herein relate to recent technology trends that are of particular interest in a New Radio (NR) context, however, embodiments are also applicable in further

development of existing wireless communications systems such as e.g. LTE or Wideband Code Division Multiple Access (WCDMA).

In the wireless communications network 1 , a user equipment (UE) 10 exemplified herein as a wireless device such as a mobile station, a non-access point (non-AP) station (STA), an STA and/or a wireless terminal, is comprised communicating via e.g. one or more Access Networks (AN), e.g. radio access network (RAN), to one or more core networks (CN). It should be understood by those skilled in the art that“UE” is a non limiting term which means any terminal, wireless communications terminal, user equipment, narrowband internet of things (NB-loT) device, Machine Type Communication (MTC) device, Device to Device (D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablet or even a small base station capable of

communicating using radio communication with a radio network node within an area served by the radio network node.

The wireless communications network 1 comprises a radio network node 12 providing radio coverage over a geographical area, a first service area, of a first radio access technology (RAT), such as NR, LTE, or similar. The radio network node 12 may be a transmission and reception point such as an access node, an access controller, a base station, e.g. a radio base station such as a gNodeB (gNB), an evolved Node B (eNB, eNode B), a NodeB, a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a Wireless Local Area Network (WLAN) access point or an Access Point Station (AP STA), a transmission arrangement of a radio base station, a stand-alone access point or any other network unit or node capable of communicating with a wireless device within the area served by the radio network node depending e.g. on the first radio access technology and terminology used. The radio network node may be referred to as a serving radio network node wherein the service area may be referred to as a serving cell, and the serving network node communicates with the wireless device in the form of DL transmissions to the wireless device and UL transmissions from the wireless device. It should be noted that a service area may be denoted as cell, beam, beam group or similar to define an area of radio coverage.

The radio network node 12 may configure the UE 10 to perform methods disclosed herein for enabling secure access to a channel of the wireless communication network 1. Embodiments herein merge an access phase and an authentication phase and carry out these procedures at the physical layer, to achieve low delays and low overhead. The UE and the radio network node 12 have a shared secret, i.e. an algorithm, which is utilized to select a pilot hopping sequence between different pilot hopping sequences. The UE 10 transmits this pilot hopping sequence over a multitude of physical resources that are separated in time and frequency. The radio network node 12 identifies the pilot hopping sequence and uses the pilot hopping sequence to identify the UE 10 and/or to decode a message from said UE 10.

By having multiple pilot hopping sequences to choose between and selecting one of them based on the ID, and the known algorithm and/or time stamp, the total number of pilot hopping sequence instances can be reduced. In some cases, this transaction might be all the data the UE 10 needs to transmit at that time, hence eliminating the need for further establishment of a more expensive connection protocol.

Embodiments herein enable authentication at the physical layer since the UE is identified and authenticated based on the received pilot hopping sequence, instead of the application layer, which can greatly reduce the latency and protocol overhead. In some embodiments, the proposed solution does not require any additional signaling for authentication since existing uplink reference signals can be utilized. Embodiments further enable rapid reconnection for UEs that have e.g. entered a dormant mode in NR.

Fig. 2 is a combined signaling scheme and flowchart according to embodiments herein.

Action 201. The UE 10 may be configured by the radio network node 12 or be pre-configured manually with a configuration defining, e.g., the algorithm. Each legitimate UE may thus have a shared secret with the radio network node 12, which in some embodiments is integrated into the SIM card and in some embodiments is generated by a public-key mechanism or by some other method.

Action 202. The UE 10 selects the pilot hopping sequence based on an identity of the UE 10 and further based on an algorithm known to the radio network node 12 and/or a time stamp of the selection. The UE 10 maps the identity, and the algorithm known to the radio network node 12 and/or the time stamp, onto a sequence of integers; and then maps the sequence of integers onto a sequence of pilot waveforms using a pre determined mapping. E.g. when the UE 10 is accessing the network, it generates one realization of the pilot hopping sequence by using a deterministic pseudo-random generator function, which pseudo-random generator function takes at least the algorithm, and the current time stamp as inputs. In some embodiments said deterministic pseudo random generator function also takes the identity of the UE 10 as input, and in some embodiments the identity of the UE 10 is implicitly included (or derived from) the algorithm. The time stamp makes sure that after one has observed the realization of the pilot hopping sequence, it is practically impossible to predict future realizations of the hopping sequence, for other time stamps i.e. the time stamp prevents playback attacks. The pilot hopping sequence may be of length n, which is a pre-determined integer, e.g. configured using dedicated radio resource control (RRC) signaling of system information (SI) broadcast.

Action 203. The UE 10 transmits the selected pilot hopping sequence to the radio network node 12. Thus, the UE 10 may transmit the corresponding pilots over a number n of physical resources, e.g. resource blocks or time instances, which number of physical resources are distributed over the time-frequency grid in a pre-determined way i.e. the predetermined mapping. Thus, the UE 10 is not only transmitting pseudo-random pilots on a deterministically selected set of subcarriers, but also hopping between subcarriers in a pseudo-random fashion. This can be viewed as a two-dimensional pilot hopping that can be utilized in a similar way for authentication.

Action 204. The radio network node 12 receives the pilot hopping sequence and authenticates the UE 10 by identifying the UE 10 based on the received pilot hopping sequence. Thus, the radio network node 12 may receive the signal from the UE 10, generally superimposed with pilot hopping sequences of other signals from other UEs.

The radio network node 12 detects which sequences were transmitted and uses the detection to identify and authenticate the accessing UE 10. The UE 10, since it knows the associated algorithm and the associated User ID, selects a legitimate pilot hopping sequence at the right time instant. The detection of the pilot hopping sequences may, for example, be done by correlating the received signal in each block with each possible pilot hopping sequence of a number of possible pilot hopping sequences and determining which ones are most likely to have been transmitted. This can, for example, be formulated as a maximum likelihood estimation problem see“Massive MIMO Unsourced Random Access” Alexander Fengler et al. CoRR abs/1901.00828 2019, or solved using approximate message passing algorithms see“Grant-Free Massive MTC-Enabled Massive MIMO: A Compressive Sensing Approach” Kamil Senel et al. IEEE Transactions on Communications Volume: 66 , Issue: 12 , Dec. 2018.

In some embodiments, when the UE 10 has been identified and authenticated, the radio network node 12 may compare the result with a list of legitimate UEs to determine if the transmitting UE is legitimate or not. In some embodiments, the list of legitimate UEs is very large and, therefore, each radio network node 12 keeps a local list of legitimate UEs that is smaller i.e. reduced in numbers. This local list may be created by letting UEs that enter a cell go through an initial higher-layer authentication step in order to be placed on the local list. In some embodiments, a UE is added to the local list when entering dormant mode.

If the radio network node 12 is equipped with multiple antennas and uses them for spatial processing and/or if the signal-to-noise ratio is high, the estimation errors can be made small.

Let t be the number of orthogonal pilots that can be transmitted in each transmission block and let n be the length of the pilot hopping sequence. There are then t ^h different pilot hopping sequences, which is a number that grows polynomially with t and exponentially with n. For a given number of pilot hopping sequences, the

computational complexity of the proposed solution may be made small by having a small number of orthogonal pilots, below a set threshold value, and a large length of the pilot hopping sequence n, above another set threshold value.

In some embodiments, pilots used in the pilot-hopping sequences are orthogonal transmission sequences while in other embodiments the pilots are non-orthogonal transmission sequences.

In some embodiments, the pilot hopping sequence is also a function of other parameters, such as the cell index. These parameters can be openly provided by the radio network node 12.

It is herein disclosed a way for authentication in the physical layer of wireless networks, where the user device transmits uplink reference signals (also called pilots). A conventional purpose of these pilots can be to perform uplink channel estimation or random access, but it is also possible to define a special set of reference signals (pilots) for this purpose. The authentication solution may be implemented without defining a new set of signals for this purpose.

Fig. 3 is a combined signaling scheme and flowchart according to some embodiments herein. Action 301. The UE 10 may perform a random access (RA) process with the radio network node 12 for gaining access to the radio network node 12.

Action 302. The UE 10 may be configured by the radio network node 12 with a configuration defining, e.g., the algorithm. The configuration may be for joint

authentication and access and may be confirmed by the UE 10.

Action 303. The UE 10 may then select the pilot hopping sequence based on the identity of the UE 10, the algorithm known to the radio network node 12 and the time stamp of the selection. This is an example of action 202 above.

Action 304. The UE 10 transmits the selected pilot hopping sequence(s) over a number of configured physical resources. This is an example of action 203 above.

Action 305. The radio network node 12 may detect received pilots in the number of physical resources configured for joint access and authentication.

Action 306. The radio network node 12 may detect the pilot hopping sequence(s) from the detected pilots over said number of physical resources.

Action 307. The radio network node 12 may identify and authenticate the UE 10. Actions 305-307 are an example of action 204 above.

Action 308. The radio network node 12 may then confirm reception and

authentication by transmitting an acknowledgement (ACK) back to the UE 10.

Embodiments herein enable authentication at the physical layer, instead of the application layer, which can greatly reduce the latency and protocol overhead. In some embodiments, the proposed solution does not require any additional signaling for authentication since existing uplink reference signals can be utilized. The solution enables rapid reconnection for UEs that have entered dormant mode in e.g. NR.

Small amounts of data can be embedded during the authentication process, which removes the need for an additional data transmission phase, particularly for users that only access the network to send a small data package. This further reduces latency and increases the energy efficiency since the overhead for authentication is reduced.

The network side complexity of the identification is low since the number of signals to detect in each block is small, while the number of hopping sequences can be large.

Fast algorithms are available that can resolve collisions between multiple colliding non- orthogonal sequences, see see“Grant-Free Massive MTC-Enabled Massive MIMO: A Compressive Sensing Approach” Kamil Senel et al. IEEE Transactions on

Communications Volume: 66 , Issue: 12 , Dec. 2018, and“Massive MIMO Unsourced Random Access” Alexander Fengler et al. CoRR abs/1901.00828 2019. Another advantage is the resilience against spoofing and jamming. If an illegitimate UE attempts to steal the identity of another user, it must try to mimic its hopping sequence. Due to the pseudo-random hopping sequences, the chance of success goes exponentially towards zero as the length of the hopping sequences increases. If a rogue terminal (e.g. a jammer) interferes with the transmission, it needs to spread its power over all possible hopping sequences, which limits the effective interference per sequence.

Embodiments herein may either replace existing solutions to increase the efficiency or be combined with existing solutions for increased security. Embodiments may be used only for small data transmissions while existing solutions (e.g. explicitly embedding a long user identifier in the data message) is used for large data transmissions (e.g. the selection may be based on a threshold of the data size to transmit).

In some embodiments this physical layer access and authentication procedure disclosed herein is used as a first authentication step (e.g. gatekeeper) that must be successfully passed before allowing a UE to communicate with another authentication node, e.g. in the core network. This way some rogue authentication requests can be terminated directly in the RAN (in the radio network node e.g. eNB, gNB, access point, etc.) and this reduces the amount of backhaul signaling that is required for authentication purposes.

The method actions performed by the UE 10 for handling communication in the wireless communication network according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 4. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes.

Action 401. The UE 10 may obtain the algorithm from the radio network node 12 or from within the UE 10.

Action 402. The UE 10 selects the pilot hopping sequence based on the identity of the UE 10 and further based on the algorithm known to the radio network node 12 and/or the time stamp of the selection. The UE 10 selects the pilot hopping sequence by mapping the identity, and the algorithm known to the radio network node 12 and/or the time stamp, onto a sequence of integers and mapping the sequence of integers onto a sequence of pilot waveforms using a pre-determined mapping. The UE 10 may select the pilot hopping sequence further based on a cell index of a cell serving the UE 10. E.g. the UE 10 may take the cell index into account when mapping onto the sequence of integers. Action 403. The UE 10 then transmits the selected pilot hopping sequence to the radio network node 12. The UE 10 may transmit the selected pilot hopping sequence over a number of resource blocks and the number of resource blocks may be selected as a function of the time stamp and the identity of the UE 10.

The method actions performed by the radio network node 12 for handling communication in a wireless communication network according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 5. The actions do not have to be taken in the order stated below, but may be taken in any suitable order.

Actions performed in some embodiments are marked with dashed boxes.

Action 501. The radio network node may configure the UE with the algorithm.

Action 502. The radio network node 12 receives a pilot hopping sequence from a UE 10 for access and authentication of the UE 10. The pilot hopping sequence may be received over a number of resource blocks. The number of resource blocks may be based on a function of the time stamp and the identity of the UE 10.

Action 503. The radio network node 12 then authenticates the UE 10 by identifying the UE 10 based on the received pilot hopping sequence. The pilot hopping sequence comprises a sequence of pilot waveforms mapped to a sequence of integers according to a predetermined mapping and the sequence of integers is mapped to an identity of the UE 10, and an algorithm known to the radio network node 12 and/or a time stamp. The radio network node 12 may then authenticate the UE 10 by detecting the pilot hopping sequence based on the identity of the UE 10, and the algorithm known to the radio network node 12 and/or the time stamp, and/or a cell index of a cell serving the UE 10.

Embodiments herein protect against spoofing. If an illegitimate UE tries to access the radio network node 12, the illegitimate UE does not know the algorithm and therefore the illegitimate UE cannot generate a legitimate pilot hopping sequence by using the pseudo-random generator function. An illegitimate UE can, however, attempt to disguise itself as a legitimate UE by generating a random pilot-hopping sequence. The chance of succeeding with this can be quantified as follows:

Let t be the number of orthogonal pilots that can be transmitted in each transmission block and let n be the length of the hopping sequence. There are then t ^h different hopping sequences, which is a number that grows polynomial^ with t and exponentially with n. Hence, the chance that a randomly selected hopping sequence matches a particular UE’s pilot hopping sequence is 1/t ^h . Suppose the list of legitimate UEs contains K users (with K £ t ^h ) and each of them has a unique pilot hopping sequence. In this case, the chance that a randomly selected hopping sequence matches one of the K users’ pilot hopping sequence is K/t ^h . Hence, even if K is large, the probability of miss-authentication can be made small by increasing n.

A jammer that targets the access procedure will have a limited amount of transmission power. When there are many pilot hopping sequences and the selection is unknown, the jammer can either target a few of them, with the risk of missing the right one, or spread its power over all of them. In any of these cases, the jammer will be less effective than when jamming a data channel that the UE has been scheduled at.

In some embodiments, a data message is embedded into the selection of the pilot hopping sequence. Let m be the number of bits to be transmitted by the UE 10, then the device generates 2 ^m unique pilot sequences, as described above, each representing one of the m-bit messages, and transmits the one corresponding to the data to be transmitted. The receiving radio network node 12 identifies the pilot hopping sequence, as described above and the radio network node 12 may then jointly detect the identity of the sending UE 10, authenticate the UE 10, and detect the embedded data. This embodiment is particularly useful in massive machine-type communication setups, where the data traffic is uplink-driven, and each UE 10 sporadically transmits a small amount of data. Another application is for the control plane, e.g. for transmission of buffer status reports, small amounts of channel state feedback, ack/nack bits and/or scheduling request.

The probability of miss-authentication, K/t ^h , is illustrated in Fig 6 for r = 10 and three different values of K: 1 , 100, and 10000 users. In each case, the probability goes exponentially towards zero as n increases. Even for a massive number of users, e.g. UE 10, such as K=10000, the probability of miss-authentication is only 10 ^-6 for n=10 and it reduces to 10 ^-16 for n=20, where n is length of the hopping sequence.

The detection of an illegitimate UE 10 is shown in the flowchart in Fig. 7. When there is embedded data in the pilot-hopping sequences, there is a tradeoff between the number of bits that are conveyed and the protection against illegitimate UEs, since a larger number of potentially used pilot sequences make it easier to randomly guess one of them.

Fig. 8 is a block diagram depicting the UE 10 for handling communication in a wireless communication network 1 according to embodiments herein. The UE 10 may comprise processing circuitry 801 , e.g. one or more processors, configured to perform the methods herein.

The UE 10 may comprise a selecting unit 802. The UE 10, the processing circuitry 801 , and/or the selecting unit 802 is configured to select pilot hopping sequence based on an identity of the UE 10 and further based on an algorithm known to a radio network node 12 and/or a time stamp of the selection, by being further configured to map the identity, and the algorithm known to the radio network node 12 and/or the time stamp, onto a sequence of integers, and to further map the sequence of integers onto a sequence of pilot waveforms using a pre-determined mapping.

The UE 10 may select the pilot hopping sequence based on a cell index of a cell serving the UE 10 by further taking the cell index into account when mapping onto the sequence of integers.

The UE 10 may comprise a transmitting unit 803. The UE 10, the processing circuitry 801 , and/or the transmitting unit 803 is configured to transmit the selected pilot hopping sequence to the radio network node 12.

The UE may be configured to transmit the selected pilot hopping sequence over a number of resource blocks. The number of resource blocks may be selected as a function of the time stamp and the identity of the UE 10.

The UE 10 may comprise an obtaining unit 804. The UE 10, the processing circuitry 801 , and/or the obtaining unit 804 may be configured to obtain the algorithm from the radio network node 12 or from within the UE 10.

The UE 10 further comprises a memory 805. The memory 805 comprises one or more units to be used to store data on, such as data packets, events and applications to perform the methods disclosed herein when being executed, and similar. Furthermore, the UE 10 may comprise a communication interface such as comprising a transmitter, a receiver and/or a transceiver.

The methods according to the embodiments described herein for the UE 10 are respectively implemented by means of e.g. a computer program product 806 or a computer program, comprising instructions, i.e. , software code portions, which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the UE 10. The computer program product 806 may be stored on a computer-readable storage medium 807, e.g. a disc, a universal serial bus (USB) stick or similar. The computer-readable storage medium 807, having stored thereon the computer program product, may comprise the instructions which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the UE 10. In some embodiments, the computer-readable storage medium may be a transitory or a non-transitory computer- readable storage medium. Thus, embodiments herein may disclose a UE for handling communication in a wireless communications network, wherein the UE comprises processing circuitry and a memory, said memory comprising instructions executable by said processing circuitry whereby said UE is operative to perform any of the methods herein.

Fig. 9 is a block diagram depicting the radio network node 12 for handling data packets or handling communication in a wireless communications network 1 according to embodiments herein.

The radio network node 12 may comprise processing circuitry 901 , e.g. one or more processors, configured to perform the methods herein.

The radio network node 12 may comprise a receiving unit 902. The radio network node 12, the processing circuitry 901 and/or the receiving unit 902 is configured to receive a pilot hopping sequence from the UE 10 for access and authentication of the UE 10.

The radio network node 12 may be configured to receive the pilot hopping sequence over a number of resource blocks. The number of resource blocks may be selected as a function of the time stamp and the identity of the UE 10.

The radio network node 12 may comprise an authenticating unit 903. The radio network node 12, the processing circuitry 901 and/or the authenticating unit 903 is configured to authenticate the UE 10 by identifying the UE 10 based on the received pilot hopping sequence, and wherein the pilot hopping sequence comprises a sequence of pilot waveforms mapped to a sequence of integers according to a predetermined mapping and the sequence of integers is mapped to an identity of the UE 10, and an algorithm known to the radio network node 12 and/or a time stamp.

The radio network node 12 may comprise a detecting unit 904. The radio network node 12, the processing circuitry 901 and/or the detecting unit 904 may be configured to detect the pilot hopping sequence based on a cell index of a cell serving the UE 10.

The radio network node 12 may comprise a configuring unit 905. The radio network node 12, the processing circuitry 901 , and/or the configuring unit 905 may be configured to configure the UE 10 with the algorithm.

The radio network node 12 further comprises a memory 906. The memory 906 comprises one or more units to be used to store data on, such as data packets, events and applications to perform the methods disclosed herein when being executed, and similar. Furthermore, the radio network node 12 may comprise a communication interface such as comprising a transmitter, a receiver and/or a transceiver.

The methods according to the embodiments described herein for the radio network node 12 are respectively implemented by means of e.g. a computer program product 907 or a computer program, comprising instructions, i.e. , software code portions, which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the radio network node 12. The computer program product 907 may be stored on a computer-readable storage medium 908, e g. a disc, a universal serial bus (USB) stick or similar. The computer-readable storage medium 908, having stored thereon the computer program product, may comprise the instructions which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the radio network node 12. In some embodiments, the computer-readable storage medium may be a transitory or a non-transitory computer-readable storage medium. Thus, embodiments herein may disclose a radio network node for handling communication in a wireless communications network, wherein the radio network node comprises processing circuitry and a memory, said memory comprising instructions executable by said processing circuitry whereby said radio network node is operative to perform any of the methods herein.

In some embodiments a more general term“radio network node” is used and it can correspond to any type of radio-network node or any network node, which

communicates with a wireless device and/or with another network node. Examples of network nodes are NodeB, MeNB, SeNB, a network node belonging to Master cell group (MCG) or Secondary cell group (SCG), base station (BS), multi-standard radio (MSR) radio node such as MSR BS, eNodeB, network controller, radio-network controller (RNC), base station controller (BSC), relay, donor node controlling relay, base transceiver station (BTS), access point (AP), transmission points, transmission nodes, Remote radio Unit (RRU), Remote Radio Head (RRH), nodes in distributed antenna system (DAS), etc.

In some embodiments the non-limiting term wireless device or user equipment (UE) is used and it refers to any type of wireless device communicating with a network node and/or with another wireless device in a cellular or mobile communication system. Examples of UE are target device, device to device (D2D) UE, proximity capable UE (aka ProSe UE), machine type UE or UE capable of machine to machine (M2M) communication, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles etc.

Embodiments are applicable to any RAT or multi-RAT systems, where the wireless device receives and/or transmit signals (e.g. data) e.g. New Radio (NR), Wi-Fi, Long Term Evolution (LTE), LTE-Advanced, Wideband Code Division Multiple Access (WCDMA), Global System for Mobile communications/enhanced Data rate for GSM Evolution

(GSM/EDGE), Worldwide Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB), just to mention a few possible implementations.

As will be readily understood by those familiar with communications design, that functions means or circuits may be implemented using digital logic and/or one or more microcontrollers, microprocessors, or other digital hardware. In some embodiments, several or all of the various functions may be implemented together, such as in a single application-specific integrated circuit (ASIC), or in two or more separate devices with appropriate hardware and/or software interfaces between them. Several of the

functions may be implemented on a processor shared with other functional

components of a wireless device or network node, for example.

Alternatively, several of the functional elements of the processing means discussed may be provided through the use of dedicated hardware, while others are provided with hardware for executing software, in association with the appropriate software or firmware. Thus, the term“processor” or“controller” as used herein does not exclusively refer to hardware capable of executing software and may implicitly include, without limitation, digital signal processor (DSP) hardware and/or program or

application data. Other hardware, conventional and/or custom, may also be included. Designers of communications devices will appreciate the cost, performance, and maintenance trade-offs inherent in these design choices.

Fig. 10 shows a Telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. With reference to Fig. 10, in accordance with an embodiment, a communication system includes

telecommunication network 3210, such as a 3GPP-type cellular network, which comprises access network 3211 , such as a radio access network, and core network 3214. Access network 3211 comprises a plurality of base stations 3212a, 3212b, 3212c, such as NBs, eNBs, gNBs or other types of wireless access points being examples of the radio network node 12 above, each defining a corresponding coverage area 3213a, 3213b, 3213c. Each base station 3212a, 3212b, 3212c is connectable to core network 3214 over a wired or wireless connection 3215. A first UE 3291 located in coverage area 3213c is configured to wirelessly connect to, or be paged by, the corresponding base station 3212c. A second UE 3292 in coverage area 3213a is wirelessly connectable to the corresponding base station 3212a. While a plurality of UEs 3291 , 3292 are illustrated in this example being examples of the UE 10 above, 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 3212.

Telecommunication network 3210 is itself connected to host computer 3230, 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 3230 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 3221 and 3222 between telecommunication network 3210 and host computer 3230 may extend directly from core network 3214 to host computer 3230 or may go via an optional intermediate network 3220. Intermediate network 3220 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 3220, if any, may be a backbone network or the Internet; in particular, intermediate network 3220 may comprise two or more sub-networks (not shown).

The communication system of Fig. 10 as a whole enables connectivity between the connected UEs 3291 , 3292 and host computer 3230. The connectivity may be described as an over-the-top (OTT) connection 3250. Host computer 3230 and the connected UEs 3291 , 3292 are configured to communicate data and/or signaling via OTT connection 3250, using access network 3211 , core network 3214, any intermediate network 3220 and possible further infrastructure (not shown) as intermediaries. OTT connection 3250 may be transparent in the sense that the participating communication devices through which OTT connection 3250 passes are unaware of routing of uplink and downlink communications. For example, base station 3212 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 3230 to be forwarded (e.g., handed over) to a connected UE 3291. Similarly, base station 3212 need not be aware of the future routing of an outgoing uplink communication originating from the UE 3291 towards the host computer 3230.

Fig. 11 shows a host computer communicating via a base station and with a user equipment over a partially wireless connection in accordance with some embodiments

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Fig 11. In communication system 3300, host computer 3310 comprises hardware 3315 including communication interface 3316 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 3300. Host computer 3310 further comprises processing circuitry 3318, which may have storage and/or processing capabilities. In particular, processing circuitry 3318 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 3310 further comprises software 3311 , which is stored in or accessible by host computer 3310 and executable by processing circuitry 3318. Software 3311 includes host application 3312. Host application 3312 may be operable to provide a service to a remote user, such as UE 3330 connecting via OTT connection 3350 terminating at UE 3330 and host computer 3310. In providing the service to the remote user, host application 3312 may provide user data which is transmitted using OTT connection 3350.

Communication system 3300 further includes base station 3320 provided in a telecommunication system and comprising hardware 3325 enabling it to communicate with host computer 3310 and with UE 3330. Hardware 3325 may include communication interface 3326 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 3300, as well as radio interface 3327 for setting up and maintaining at least wireless connection 3370 with UE 3330 located in a coverage area (not shown in Fig. 11) served by base station 3320. Communication interface 3326 may be configured to facilitate connection 3360 to host computer 3310. Connection 3360 may be direct or it may pass through a core network (not shown in Fig. 11) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 3325 of base station 3320 further includes processing circuitry 3328, 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 3320 further has software 3321 stored internally or accessible via an external connection.

Communication system 3300 further includes UE 3330 already referred to. Its hardware 3333 may include radio interface 3337 configured to set up and maintain wireless connection 3370 with a base station serving a coverage area in which UE 3330 is currently located. Hardware 3333 of UE 3330 further includes processing circuitry 3338, 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 3330 further comprises software 3331 , which is stored in or accessible by UE 3330 and executable by processing circuitry 3338.

Software 3331 includes client application 3332. Client application 3332 may be operable to provide a service to a human or non-human user via UE 3330, with the support of host computer 3310. In host computer 3310, an executing host application 3312 may communicate with the executing client application 3332 via OTT connection 3350 terminating at UE 3330 and host computer 3310. In providing the service to the user, client application 3332 may receive request data from host application 3312 and provide user data in response to the request data. OTT connection 3350 may transfer both the request data and the user data. Client application 3332 may interact with the user to generate the user data that it provides.

It is noted that host computer 3310, base station 3320 and UE 3330 illustrated in Fig. 11 may be similar or identical to host computer 3230, one of base stations 3212a, 3212b, 3212c and one of UEs 3291 , 3292 of Fig. 10, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 11 and independently, the surrounding network topology may be that of Fig. 10.

In Fig. 11 , OTT connection 3350 has been drawn abstractly to illustrate the communication between host computer 3310 and UE 3330 via base station 3320, 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 3330 or from the service provider operating host computer 3310, or both. While OTT connection 3350 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 3370 between UE 3330 and base station 3320 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 3330 using OTT connection 3350, in which wireless connection 3370 forms the last segment. More precisely, the teachings of these embodiments make it possible to enhance the CWS maintenance scheme for PUCCH transmission and/or a better fairness of channel accesses may be achieved. Embodiments herein may e.g. enable the radio network node to more efficiently control the performance of the UEs by configuring the UEs according to embodiments herein for authentication, and to more efficiently detect pilot sequences. 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 3350 between host computer 3310 and UE 3330, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 3350 may be implemented in software 3311 and hardware 3315 of host computer 3310 or in software 3331 and hardware 3333 of UE 3330, or both. In embodiments, sensors (not shown) may be deployed in or in association with

communication devices through which OTT connection 3350 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 3311 , 3331 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 3350 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 3320, and it may be unknown or imperceptible to base station 3320. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 3310’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 3311 and 3331 causes messages to be transmitted, in particular empty or‘dummy’ messages, using OTT connection 3350 while it monitors propagation times, errors etc.

Fig. 12 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments.

Fig. 12 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 Fig. 10 and Fig. 11. For simplicity of the present disclosure, only drawing references to Fig. 12 will be included in this section. In step 3410, the host computer provides user data. In substep 3411 (which may be optional) of step 3410, the host computer provides the user data by executing a host application. In step 3420, the host computer initiates a transmission carrying the user data to the UE. In step 3430 (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 3440 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer. Fig. 13 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments.

Fig. 13 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 Fig.

10 and Fig. 11. For simplicity of the present disclosure, only drawing references to Fig. 13 will be included in this section. In step 3510 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 3520, 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 3530 (which may be optional), the UE receives the user data carried in the transmission.

Fig. 14 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments.

Fig. 14 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 Fig.

10 and Fig. 11. For simplicity of the present disclosure, only drawing references to Fig. 14 will be included in this section. In step 3610 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 3620, the UE provides user data. In substep 3621 (which may be optional) of step 3620, the UE provides the user data by executing a client application. In substep 3611 (which may be optional) of step 3610, 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 3630 (which may be optional), transmission of the user data to the host computer. In step 3640 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. 15 show methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments.

Fig. 15 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 Fig. 10 and Fig. 11. For simplicity of the present disclosure, only drawing references to Fig. 15 will be included in this section. In step 3710 (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 3720 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 3730 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

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.

It will be appreciated that the foregoing description and the accompanying drawings represent non-limiting examples of the methods and apparatus taught herein.

As such, the apparatus and techniques taught herein are not limited by the foregoing description and accompanying drawings. Instead, the embodiments herein are limited only by the following claims and their legal equivalents. Abbreviation Explanation

ACK (positive) Acknowledgment

AUL Autonomous uplink

BLER Block error rate

BWP Bandwidth Part

CAPC Channel access priority class CBG Code block group

CCA Clear channel assessment

CO Channel occupancy

COT Channel occupancy time

CWS Contention window size

DL Downlink

ED Energy detection

eNB 4G base station

gNB 5G base station

HARQ Hybrid automatic repeat request

IS In synch

LAA Licensed assisted access

LBT Listen before talk

MAC Medium access control

MCOT Maximum channel occupancy time

NACK Negative acknowledgment

NDI New data indicator

NR 3GPP defined 5G radio access technology NR-U NR unlicensed

OOS out of synch

PCell Primary cell

PCI Physical cell identity

PDCCH A downlink control channel

PDU Protocol data unit

PHICH Physical channel Hybrid ARQ Indicator Channel PLMN Public land mobile network

PSCell Primary SCG cell

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

QCI QoS class identifier

QoS Quality of service

RAT Radio access technology

RLF Radio link failure

RLM Radio link monitoring

RLC Radio link control RRC Radio resource control

RS Reference signal

SCG Secondary cell group

SDU Service data unit

SMTC SSB— based measurement timing configuration SpCell Special cell (PCell or PSCell)

SPS Semi persistent scheduling

TTI Transmission time interval

UCI Uplink Control Information

UE User equipment

UL Uplink