Patent Description:
In proposed future network infrastructures end-to-end service-based architecture (SBA) and/or cloud-native driven telecommunication infrastructure as well, end-devices will be part of a cloud-native environment. Such end-devices can be vehicles, drones, trains and/or user equipment like smartphones, tablets, computers. In the following, we will name all those devices for simplicity reasons user equipment (UE). The UE is configured to communicate at least over a mobile radio (<NUM>, <NUM>, Wi-Fi, Bluetooth, and future 3GPP and IEEE radio interfaces) communication link.

The idea behind a cloud-native infrastructure is that necessary data is being outsourced from an actual domain, an entity, a device, a network function and/or a UE (statelessness of entities) to a database connected through a communication network. The necessary data is the data of the respective network functions that is being processed to provide a service or to run an application. The network functions perform certain tasks relating to the execution of the application and/or providing the (communication) service. For example, this means that the UE stores its data within a state and parameter database within the communication network instead or in addition of storing it on its own memory.

Hence, the end-to-end architecture comprises different domains that fulfill different tasks within the communication network. The domains can be actual entities and/or can be implemented as virtual entities on servers. Those domains can be a central cloud, a transport, multi-access edge computing instances, different (radio) access networks, and end-device(s). Those domains comprise the typical hardware that is configured to provide connectivity, storage, and processing units. The network functions can be implemented on the processing units as algorithms.

Functional-wise, each domain will have network functions (NF) in the data plane (DP) for forwarding and manipulation of the user and application traffic and in the control plane (CP) for the setup and control of the data plane network functions (DP NFs). The database for the NFs is the network data layer (NDL). In 3GPP the data plane is called a user plane (UP).

Hence, the NFs will not keep the states and parameters after successful execution of the function but store them in the database. When processes start, each NF will request or pull its required states and/or parameters from that (external) database and after completing the execution of the function, each NF will send or push the new states and/or new parameters back into this database. The database can be a distributed element of the cloud.

Hence, the database is an elementary part of all the data traffic. As this provides many advantages, this can also cause problems in certain cases. If one of the domains and/or the UE suffers from a broken communication link to the database, its network functions cannot fulfill its tasks because they cannot pull and/or push the data into the database. These cases are likely to happen if the UE is being connected by means of a radio technology (<NUM>, <NUM>, Wi-Fi, Bluetooth, and future 3GPP and IEEE radio interfaces) to the rest of the communication network. Typically, all the other domains can be located within the core of the communication network that does not suffer from unstable communication links. The radio communication links can be interrupted according to certain connection conditions like if the line of sight cannot be provided anymore, a distance to the base station is too far, no hand-over to another base station is possible, the connection plug was pulled off, etc..

As a result of such a loss of communication due to a broken radio link, the UEs are not anymore part of the end-to-end system and the corresponding data traffic will be lost so that it can happen that the communication, service and/or application cannot run anymore.

<CIT> (TATA CONSULTANCY SERVICES LTD [IN]) <NUM> March <NUM>, considers the cases of loss of the UE or network loss or damaged UE with corrupted memory, etc. A virtual image of the UE is created in the (virtual) network. The virtual image also runs in the UE.

<CIT> (CITRIX SYSTEMS INC [US]) <NUM> July <NUM>, discloses a pseudo device being representative of a user device. The pseudo device may run in cloud environment.

In the view of above, it is an object of the present invention to provide techniques that enable running a communication, a service and/or application even if the communication link to an UE breaks at least temporarily.

According to a first aspect of the invention, a method for communication in a communication system is being provided. In particular, the communication is being related to running a certain communication service and/or application.

It is also possible that the setup of the UE-substitute-unit can be related to certain context information and/or machine learning algorithms and can depend on the likelihood that the radio communication link might be interrupted for a certain time. As already explained above, the UE-substitute-unit mimics the NF of the UE and can be synchronized with the UE to obtain the NF of the UE that shall be used next. This synchronization provides the advantage that the UE-network-function of the UE-substitute-unit is always up-to-date and can take over as soon as the connection to the UE is being lost. Typically, CP NFs will respond to requests, wherein DP NFs will reply with data traffic. In an embodiment, when the UE is being connected to the communication system again, the UE-substitute-unit can also synchronize its status and can go into an observer mode again. However, it is also possible that the observer mode is being done by a UE-substitute-controller - as will be explained in the following. The UE-substitute-controller and the UE-substitute-unit can be implemented as a single UE-substitute-entity.

In an embodiment, the communication link between the various domains is multicast and/or bus capable. In an embodiment, the address of the multicast message is defined in the multicast address range of the communication system and is the same for the UE and the UE-substitute-controller and/or the UE-substitute-unit. If the UE-substitute-controller sets up the UE-substitute-unit - as will be discussed in the following - the UE-substitute-controller can be configured to forward the data packet to the UE-substitute-unit.

This provides the advantage that the data packets can be sent to a certain domain, for example the UE, and that another domain and/or the UE-substitute-controller is aware that the data packet has been sent to the UE. Another advantage of the multicast capability is that more than one domain can be assigned to the data packet. Hence, if a first and the second domain are specified with their respective destination addresses within the data packet, the second domain could take over the processing of the data packet, if the first domain does not respond, for example because it suffers from a broken link. As an example, the UE-substitute-unit can take over the processing of the data packet if the UE does not respond. The communication between the domains and/or the respective NFs can be ensured by means of a service-based interface. This can work based on a producer-consumer principle. The SBI can be configured to be a bus or another communication architecture. Using a bus architecture provides the advantage that all the other domains are aware of all the data packets that are being sent over the communication link.

This enables that domains and/or NFs can listen in the background if the data packet is being processed by the domain and/or NFs that corresponds to its destination address. As an example: The UE-substitute-unit and/or the UE-substitute-controller know that the data packet is actually being sent to the UE because it can read the corresponding destination address of the UE. The UE-substitute-unit and/or the UE-substitute-controller can listen to the data traffic and can observe that the UE did not process the data packet because it did not send an appropriate answer. The answer can be a data packet to the state and parameter database. For that purpose, the UE-substitute-unit and/or the UE-substitute-controller has to also know the address of the state and parameter database. Hence, the UE-substitute-unit can take over the processing of the data packet intended for the UE if the UE does not send an answer and/or if the UE-substitute-unit determines that the communication link to the UE is broken.

In the latter case that the UE-substitute-unit needs not to wait for the appropriate answer this speeds up processing of the data packet and reduces latency.

In an embodiment, the UE and/or an application "App" running on the UE triggers an instantiation of the UE-substitute-unit. The trigger signal can be sent to the UE-substitute-controller, which sets up the UE-substitute-unit. Hence, the UE and/or the app can be provided with an address of the UE-substitute-unit and/are the UE-substitute-controller. It is possible, that this address is being exchanged during the handshake communication to set up the communication of the UE. The UE-substitute-controller can be implemented within the UE and/or within the core of the communication system.

This provides the advantage that the UE and/or an application running on the UE anyhow regularly check the quality of its radio link. Hence, the UE is a very efficient location and determining the quality of the communication link. Hence, the UE and/or the App can trigger the instantiation of the UE-substitute-unit. The instantiation can comprise synchronizing an already implemented UE-substitute-unit with the current network function of the UE and/or to actually set up the UE-substitute-unit as a virtual or cloudified entity on a server. Typically, one implementation of the UE-substitute-unit as hardware can serve for more than one UE. In this case, the UE-substitute-unit needs to be provided with an ID of the UE and/or the service so that it can assign the processing of the data packet accordingly. Initiating the UE-substitute-unit based on the trigger signal, provides the advantage that network resources can be spared if the communication links are stable, and the UE-substitute-unit will not be used or that it is highly unlikely to use the UE-substitute-unit. In an embodiment, a setting of the UE and/or a setting of an application "App" running on the UE triggers an instantiation of the UE-substitute-unit. This provides the advantage that it can be chosen if the UE and/or the app sends the triggers signal or not.

In an embodiment, an UE-substitute-controller, in particular the UE-substitute-controller mentioned above, and/or the UE monitors the quality of the radio link sends the trigger signal to instantiate the UE-substitute-unit.

This provides the advantage of having different criteria when to use the UE-substitute-unit. Those criteria can be based on the experience of multiple users and/or on the scale of single users of the UE.

The UE-substitute-controller implemented within the core of the communication system can monitor the quality of the radio link of multiple UEs. It is possible that the UE-substitute-controller monitors the quality of the radio link by analyzing data packets, the condition of network cells in which the UE is being located and/or by receiving the trigger signal mentioned above. The first option can be described as an active monitoring, wherein the second option can be described as passive monitoring.

In an embodiment, the application running on the UE and/or a user defines the first threshold and/or the second threshold.

This provides the advantage that the threshold can be set individually according to different use cases.

In an embodiment, the UE-substitute-unit and/or the UE-substitute-controller signals a communication address of the UE-substitute-unit to the other domain units.

This provides the advantage that the UE-substitute-unit and/or the UE-substitute-controller can be addressed by using multicast techniques when sending the data packet.

In an embodiment, UE-substitute-controller is implemented on the UE or within other parts of the communication system, in particular within the core of the communication system.

If the UE-substitute-controller is implemented on the UE this provides the advantage that can be used by different services and/or applications running on the UE and that the UE-substitute-controller is being implemented at the location, namely within the UE, that anyhow monitors the quality of the radio link regulatory. Implementing the UE-substitute-controller within the other parts of the communication system provides the advantage that the method even works with legacy UEs.

In an embodiment, the UE-substitute-unit is being implemented within the communication system, in particular within the core of the communication system or close to the location of the related application/service within the communication system. In particular, the communication link that connects the UE-substitute-unit with the bus architecture is a fixed line, e.g. xDSL or Ethernet.

This provides the advantage of having a very stable communication link for the communication with the UE-substitute-unit and/or that latency is being reduced if the location is being close to the location of the related application/service within the network.

In an embodiment, the UE-network-function of UE-substitute-unit is updated with the actual network-function of the UE or with all the network functions relating to a certain service or application of the UE. This update process can be facilitated by exchanging the actual network function with the UE as long as the communication link is not yet broken. It is possible that this exchange is being done if it gets likely that the broken link will occur soon. Another possibility is to exchange the network functions relating to the service and/or to the application at the start of the communication. In this case, the UE-substitute-unit and/or the UE-substitute-controller can monitor the data traffic between the UE and the application and/or the service within the communication network and determine which is the current network function that shall be used by the UE-substitute-unit (which is the network function the UE would use next).

This provides the advantage that it is not necessary to store a large number of network functions within the UE-substitute-unit that cover all possible services and/or applications. This also provides the advantage that the network functions are always up-to-date and/or that the UE-substitute-unit can be set up on demand.

In an embodiment, the UE-substitute-unit at least temporarily substitutes the UE if the UE does not execute its network functionality for a certain time-period. In an embodiment, the certain time-period depends on the currently implemented network function on the UE-substitute-unit, on the application running on the UE and/or on user preferences.

This provides the advantage that the UE-substitute-unit can monitor the activity of the UE in the background and only process data if the certain time-period has been elapsed. In particular, the certain time-period is set according to the service and/or the application running on the UE. This provides the advantage that different time-periods can be chosen that account that it might take different time-periods to execute different network functions. Hence, the certain time-period can be tailored the actual use case in order to reduce latency.

In an embodiment, the UE-substitute-unit is closed after executing of the UE-network-function and/or writing the data output into the database. In other words, if the UE-substitute-unit is implemented as a virtual or cloudified unit on a server, the corresponding memory is being freed again.

This provides the advantage that no memory is being blocked if it is not used, this provides the possibility of creating a very flexible and efficient network environment.

According to a second aspect of the invention, a UE-substitute-controller for communication in a communication system is disclosed, wherein the UE-substitute-controller comprises a communication interface that is configured to monitor a quality of a radio link that is used by an UE and/or to receive a trigger signal from the UE, wherein the UE-substitute-controller is configured to trigger an instantiation of an UE-substitute-unit by sending a trigger signal or that the UE-substitute-controller is configured to instantiate the UE-substitute-unit by itself if.

If the UE-substitute-controller send the trigger signal, another entity within the network will actually instantiate the UE-substitute-unit. This other entity can be a further UE-substitute-controller. For example: A first UE-substitute-controller can be implemented within the UE. This first UE-substitute-controller can send the trigger signal to a second UE-substitute-controller located at the core of the network, wherein the second UE-substitute-controller instantiates the UE-substitute-unit on receiving the trigger signal. The UE-substitute-controller can be implemented on the UE or within the communication network. The UE-substitute-controller can also be configured to execute the steps of the method described above, which are related to it. In particular, the UE-substitute-controller is configured to send the address of the UE-substitute-unit to the other domains so that the UE-substitute-unit can address the UE-substitute-unit. In an embodiment, the UE-substitute-unit is configured to substitute the UE without having explicitly being addressed within the data packet. This is because the UE-substitute-unit receives the data packet due to the bus architecture of the communication link anyhow and can take over if the UE is not being available based on the criteria explained above.

This provides advantages that are basically analog described within the context of the inventive method.

According to a third aspect of the invention, a UE-substitute-unit of a communication system is disclosed, wherein the UE-substitute-unit comprising at least one UE-network-function of a UE, wherein the UE-substitute-unit is configured to at least temporarily substitute the UE by retrieving data from a database and/or to write data output obtained by its at least UE-network-function into the database. The UE-substitute-unit can also be configured to execute the other steps of the method described above that are related to the UE-substitute-unit. The UE-network-function mirror the functionality of the UE. In particular, the UE-substitute-unit can be related to a certain UE so that only substitutes this certain UE. The UE-substitute-unit can be a standalone unit or can be implemented virtually or cloudified on the server of the communication system in particular, the UE-substitute-unit comprises a communication interface that is being configured to exchange data traffic with the communication link to which the domains are being connected to. In particular, this communication interface is based on a fixed line communication link to a provide stable communication environment. For that purpose, the UE-substitute-unit can be located within the core of the communication.

According to a fourth aspect of the invention, a communication system is disclosed that is being configured to execute the steps of the method described above. In particular, the communication system comprises the UE-substitute-controller and/or the UE-substitute-unit. The communication system can also be named network or communication network. Within the context of this invention, these terms do not result in any technical difference.

<FIG> shows an overview of an end-to-end service-based architecture of a (tele) communication system <NUM> according to the invention.

An upper part of the picture <NUM> shows a full cloud view of the communication system <NUM> that shows various network functions <NUM> connected by means of a service-based interface (SBI) <NUM>, wherein the SBI <NUM> serves as a communication link <NUM> to enable data traffic between the various network functions designed as a communication bus <NUM> architecture. It is shown that a first part of the network functions <NUM> operate on the control plane <NUM>, wherein a second part of the network functions <NUM> operate on the data plane <NUM>. The network functions <NUM> pull and/or push necessary data for processing a service and/or an application into a state and parameter database <NUM> that can also be connected via the communication link <NUM>. Hence, it is a prerequisite of executing the service and/or the application that all the network functions <NUM> have an active communication link <NUM> to the state and parameter database <NUM>.

A lower part of the picture shows the domain view <NUM>, wherein the network functions of the upper part of the picture <NUM> are related to the respective entities shown in the domain view <NUM>. Domains units <NUM> comprise an end device <NUM> that will be called a UE <NUM> in the following. The UE <NUM> communicates via a radio link 116a with the rest of the communication system <NUM> by sending its traffic to a radio access network <NUM> that is in data communication with multi access edge computing devices <NUM>, data transport means <NUM> and/or a core <NUM> of the communication system. It is also shown that the domains units <NUM> can comprise connection interfaces <NUM>, storage means <NUM> and processing power <NUM>. The communication link 116b behind the radio access network <NUM> in direction of the core <NUM> is in general more stable than the radio link 116b.

<FIG> shows the communication system of <FIG> with a broken radio link <NUM> connecting the UE <NUM> to the communication system. As no data traffic can be send over the broken radio link <NUM>, the UE <NUM> cannot push and/or pull data that is necessary to run its network functions <NUM> to the state and parameter database <NUM>. Hence, data traffic will get lost in this scenario and applications and/or services can at least temporarily not run.

<FIG> shows how data loss and/or termination of the service or application can be avoided by placing a UE-substitute unit <NUM> within the communication system <NUM>. In principle, the location of the UE-substitute unit <NUM> can be chosen arbitrarily with the exception that the UE-substitute unit <NUM> shall not exchange its data via the radio link 116a because in this case the UE-substitute unit <NUM> will not be able to substitute the UE <NUM> if the radio link 116a breaks. The full cloud view shows that the UE-substitute unit <NUM> comprises at least one UE-network function <NUM> that mirrors the corresponding network function of the UE <NUM> and that is connected by means of the SBI <NUM> with the other network functions and/or with the state and parameter database <NUM>. Hence, if the radio link 116a breaks the UE-substitute unit <NUM> can at least temporarily substitute the UE <NUM>. In this scenario, the at least one UE-network function <NUM> acts like the corresponding network function of the UE <NUM> so that all the other domain units <NUM> basically "see" no the difference because all the necessary data needed by them can be pulled from the state and parameter database <NUM>.

In addition, <FIG> shows an optional UE-substitute-controller <NUM> that can be implemented in the UE <NUM> and monitors the quality of the radio link 116a and calculates the likelihood that the radio link 116a will fail in the near future. In this case, the UE-substitute-controller <NUM> can send a trigger signal to instantiate the UE-substitute unit <NUM> within the communication system <NUM>. For example, the UE-substitute-controller <NUM> can send the trigger signal if the signal strength of the radio link 116a is below a first threshold, the bandwidth is below a second threshold and/or the latency is larger than the third threshold.

<FIG> shows a workflow of the communication of the communication system of <FIG> with an intact radio link 116a.

A network function of any of the domain units <NUM> sends a request <NUM> over the SBI interface <NUM>. The data package of the request can be designed to use multicast addressing. The address of the multicast message is defined in the multicast address range of the communication system and is the same for the UE <NUM> and the UE-substitute-unit <NUM>. When the UE-substitute unit <NUM> registers the request <NUM>, it can be configured to start <NUM> a timer. If the UE <NUM> executes the request <NUM> and provides the corresponding parameters into the state and parameter database <NUM> before the timer is stopped <NUM> and sends the corresponding reply <NUM>, the UE-substitute unit <NUM> can conclude that the UE <NUM> works properly and that the radio link 116a is active so that data transfer is possible.

<FIG> shows the workflow of <FIG> in greater detail.

In step <NUM>, the network function of the domain unit <NUM> sends a request to the UE <NUM>. Step <NUM>: Parallel to that, the UE-substitute unit <NUM> is listening the data traffic and starts <NUM> the timer. Step <NUM>: the UE <NUM> request the necessary data to execute its network function from the state and parameter database <NUM>. Step <NUM>: the UE <NUM> reads the data and in step <NUM>, the network function of the UE <NUM> processes the data. Step <NUM>: the UE <NUM> writes the data back into the state and parameter database <NUM>. Step <NUM>: the state and parameter database <NUM> confirms successful writing of the data into the state and parameter database <NUM> to the UE <NUM>. Step <NUM>: the UE <NUM> can send a reply to another domain unit <NUM> to continue the service. During all this time, the UE-substitute-unit <NUM> is listening to the data traffic. In step <NUM> the timer is stopped <NUM>.

<FIG> shows a workflow of the communication of the communication system <NUM> of <FIG> with a broken radio link 116a of the UE <NUM>.

The network function of any of the domain units <NUM> sends a request <NUM> over the SBI interface <NUM>. The data package of the request can be designed to use multicast addressing. The address of the multicast message is defined in the multicast address range of the communication system and is the same for the UE <NUM> and the UE-substitute-unit <NUM>. However due to the broken radio link 116a, the request cannot reach the UE <NUM>. When the UE-substitute unit <NUM> registers the request <NUM>, it can be configured to start <NUM> a timer. Since the UE-substitute unit <NUM> does not observe any data communication from the UE <NUM> until the timer is stopped <NUM> it can conclude that the radio link 116a is broken and that the UE <NUM> is not being able fulfill its tasks. In this case, the UE-network function that is implemented within the UE-substitute unit <NUM> takes over processing <NUM> the request <NUM> by exchanging the corresponding data with the state and parameter database <NUM>. Hence, as the UE-substitute unit <NUM> takes over, no data traffic will get lost.

In step <NUM>, the network function of the domain unit <NUM> sends a request <NUM> to the UE <NUM>. Step <NUM>: Parallel to that, the UE-substitute unit <NUM> is listening the data traffic and starts <NUM> the timer. Due to the interrupted radio link 116a, the request <NUM> cannot reach the UE <NUM> and cannot be processed accordingly. In step <NUM> the timer is stopped <NUM> and the UE-substitute unit <NUM> concludes that the UE <NUM> is disconnected from the communication system <NUM> because it did not observe any data traffic from the UE <NUM> while being in its listening modus. Hence, the UE-substitute-unit <NUM> takes over and substitutes the UE <NUM> at least temporarily. In step <NUM>, the UE-substitute-unit <NUM> requests the data from the state and parameter database <NUM> and reads the data in step <NUM> accordingly. In step <NUM>, the UE-substitute-unit <NUM> processes the data and write the data in step <NUM> back into the state and parameter database <NUM>. In step <NUM>, the state and parameter database <NUM> confirms that the data was successfully written within its database. In step <NUM>, the UE-substitute-unit <NUM> sends a reply message to one of the domain units <NUM> so that the service/application can continue.

The NFs of the UE <NUM> will serve and control a number of higher layer applications (not depicted in the figures).

The waiting time of the timer can be defined by context information (e.g. measurements) of previous request-reply processes or by input of a machine learning system. In the first case, it might be extended by a security factor, e.g. the double of the measured time or by a result of a machine learning process as well.

Following the SBA/cloud-native principles, the NFs of the UE <NUM> and the duplicated NF of the UE-substitute-unit <NUM> should not keep parameters and states. This information is stored in the state and parameter database <NUM>. It can make sense to add an additional field in the database <NUM> to indicate that the NF of the UE <NUM> might be represented by the corresponding NF of the UE-substitute-unit <NUM>. This enables the NF of the UE <NUM> in case of a connection loss and a reconnection to trigger higher layer UE applications for an update and refresh process. It is also possible that the higher layer UE <NUM> applications will follow the SBA/cloud-native principles and all states and parameters are stored in the state and parameter database <NUM>. In this case, the NFs of the UE <NUM> can trigger the higher layer UE applications to contact the state and parameter database <NUM> for refreshing and updating.

<FIG> shows a <NUM> core architecture communication system with a network function connected via a non-interrupt-free SBI connection;.

As an example: A current <NUM> Core is mainly but not completely implemented following the SBA/cloud-native principles. For adapting the invention to a <NUM> Core, a candidate for an end-device NF might be the Application Function (AF), which can run in a mobile device, e.g. a car, robot, handheld, etc..

<FIG> shows the communication system of <FIG> with the inventive UE-substitute-unit <NUM> that shows a copy of the application function so that it can mimic the functionality of the UE <NUM>.

Claim 1:
A method for communication in a communication system, comprising the following steps
• providing domain units of a service-based architecture of the communication system, wherein the domain units provide, by means of network functions, a functionality of the network; wherein at least one of the domain units is represented by a UE having at least one UE-network-function, wherein the UE communicates with the network by means of a radio link;
• providing a database within the network, wherein the domain units communicate via a communication link with the database, and wherein the domain units to execute their network functionality, each retrieve data from the database and/or write data output obtained by their network functions into the database;
• providing a UE-substitute-unit within the communication system having at least one of said UE-network-functions, said UE-substitute-unit at least temporarily substituting for said UE, wherein the UE-substitute-unit executes the at least UE-network-functions and retrieves data from said database and/or writes data output obtained by the UE-network-function into said database.