Handover of MEC application

Field of the invention The present invention relates to an apparatus, a method, and a computer program product related to MEC. In particular, the present invention may be related to handover of a MEC application.

Abbreviations

2G/3G/4G/5G 2 ^nd /3 ^rd /4 ^th /5 ^th Generation

3GPP 3 ^rd Generation Partnership Project

ANR Automatic Neighbor Relationship

BSC Base Station Controller

BTS Base Transceiver Station, Base Station

C-plane Control Plane

eNB evolved NodeB

ETSI European Telecommunications Standards Institute

HO Handover

LTE Long Term Evolution

MEC Mobile Edge Computing

MME Mobility Management Entity

NB NodeB

QoS Quality of Service

RIM Radio Information Management

RNC Radio Network Controller

RNIS Radio Network Information Service

SIM Subscriber Identity Module

TS Technical Specification

UE User Equipment

UICC Universal Integrated Circuit Card

UMTS Universal Mobile Telecommunication System

USIM Universal Subscriber Identity Module

UTRAN UMTS Terrestrial Radio Access Network

WLAN Wireless Local Area Network Background of the invention

Cellular mobile networks provide voice and data connections for the mobile user equipment ("UE"). The cellular network comprises many base stations ("BTS", e.g. eNB in LTE). Each of these base stations is able to maintain connections to the UE in a limited coverage area defined by the "cells" of the base station. Once a UE moves out of the coverage area of one cell (source cell) into the coverage area of another cell (target cell), the mobile network and the UE are applying well-defined, standardized procedures to handover the UE from the source cell to the target cell, while maintaining any ongoing voice call and data traffic. This applies for handovers between cells of the same BTS as well as for cells between different BTS.

Although the detailed mechanisms of handover are different in the different radio access technologies, such mechanisms are available in all mobile networks, irrespective of the specific radio technology (e.g. 2G/3G/4G/5G networks of 3GPP).

For various reasons, some of the base stations may be associated with one or more Mobile Edge Computing platforms ("MEC") to provide computing resources closer to the UE. This enables local services that are processed locally at site. It avoids the need to transfer all data through the core network in order to reach the service provider. This can be used e.g. to reduce the latency of data transmissions, to cache content locally that shall be transmitted to the UE in a specific area, or to perform calculations that are relevant for specific UE at the location of the base station. Currently the mobility of UE with respect to voice calls and data transmissions has been well- defined in the various standards for mobile networks. If the UE moves from one cell to the other, the mobility management procedures of the cellular mobile network are ensuring seamless handover of voice calls and data transmissions. For example, as shown in Fig. 1 , in LTE, handover from a source BTS (eNB) to a target BTS (eNB) is controlled by the X2 interface or by the S1 interface via MME.

In contrast, the services that are provided locally by the MEC applications of the MEC platform associated with a specific BTS do not move with the moving UE through the cellular network. If the UE moves to another base station and gets connected to cells of the target base station, then it loses the services provided by the application running in the MEC platform. If the MEC platform associated with the target BTS also runs this service, then the UE has to re-register for this service. If the MEC platform associated with the target BTS does not run this specific service in its MEC platform, then the UE is not able to use this service. For certain services provided by the mobile edge platform this behaviour is reasonable and desirable, e.g. if the service intentionally is provided to a certain area only. E.g. a service to provide video sequences to a sports event might be restricted to the cells that are covering the stadium. If the UE moves out from the stadium then it shall not receive the video anymore.

However, if the mobile edge computing resources shall be used to provide services for use cases like autonomous driving, low latency remote control, or data collection for moving platforms, then it is required that, from UE point of view, the serving MEC application running in the MEC platform associated with the source BTS is able to move together with the moving UE to the target BTS, as shown in Fig. 1 .

If the corresponding application already is available at the target BTS, then it would be sufficient to move the application context from source to target. If the application is not available at the target, then the application must be instantiated at the target first. This means that mobile edge computing requires a mobility concept, in a similar way as it exists for the mobility of voice and data services.

In current 3G and 4G networks the mobile edge computing is not yet widely deployed and serves only very limited use cases, therefore the problem is not too serious. However, in future 5G networks it is expected that mobile edge computing will be used to enable mission critical, low-latency use cases.

Several documents analyse the mobility of MEC applications. So far all assume a central approach and an approach that builds a mobility system for MEC by its own, nearly independent from the regular mobility management of the cellular network.

Some approaches ("Poster: Migrating running applications across mobile edge clouds", Andrew Machen, Shiqiang Wang, Kin K. Leung, Bong Jun Ko, and Theodoros Salonidis in Proceedings of the 22nd Annual International Conference on Mobile Computing and Networking, Pages 435-436, New York City, New York— October 03 - 07, 2016, ACM New York, NY, USA ©2016, ISBN: 978-1 -4503-4226-1 ) are proposing to use a hierarchical architecture to store the state of the application at the source cell into a virtual machine image or container image, move this image (several GB) to the target and instantiate it there.

For a network with many 10.000 cells any central approach does not scale well. Further it is unreasonable to move image files of several GB in size per each moving UE.

3GPP

Standardization of MEC in 3GPP mentions "mobility of MEC applications" as open and "to be done".

ETSI MEC

A corresponding work items of ETSI is still ongoing. Some results are disclosed in ETSI MEC-0018 E2E Mobility v2.4:

ETSI MEC-0018 E2E Mobility v2.4: introduces a ,,/WE Orchestrator" as central entity to find the neighboring target MEC platforms. This approach has two disadvantages:

^■ => Central entities do not scale well. The target for pervasive networking as envisaged for 5G should be a distributed architeture.

■=> It is a kind of anachronism to base the concept of distributed computing on a central entity.

ETSI MEC-0018 E2E Mobility v2.4: "ETSI MEC foresees that the application can react to such handover events" and "ETSI MEC foresees that the application can react to such handover events by application-specific means, or, if the optional SmartRelocation feature is supported, that the mobile edge system relocates the application instance serving the UE to the target host'. This approach has several potential issues:

■=> Mobility of MEC is mainly reactive, MEC follows the radio

^■ => ETSI "SmartRelocation" might try to predict the target, to be able to follow the radio better.

^■ => MEC builds a mainly independent mobility management, although mobility of UE and mobility of MEC services are tightly related to each other.

■=> Radio does not consider MEC for its decision on handover. In worst case the BTS might perform a handover to a BTS that does not support MEC at all. MEC would have no possibilities to react on this ETSI MEC-0018 E2E Mobility v2.4 states: "...it may be appropriate to preconfigure a set of ME hosts, where the ME application is allowed to run as the user moves. This set of ME hosts may be called a "relocation group". The group may be created based on the topological or physical location of ME hosts with regards to the application end users."

Summary of the invention

It is an object of the present invention to improve the prior art. According to a first aspect of the invention, there is provided an apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform inquiring, from a source mobile edge computing platform, a usage information for a terminal indicating a mobile edge computing application of the source mobile edge computing platform used by the terminal; requesting, from a target base station, a support information indicating if the mobile edge computing application is supported at the target base station; deciding on a handover of the terminal to the target base station based on the usage information and the support information. According to a second aspect of the invention, there is provided an apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform monitoring if a request to provide a usage information for a terminal indicating a mobile edge computing application of a source mobile edge computing platform used by the terminal is received from a source base station; determining if the terminal uses the mobile edge computing application; preparing the usage information based on a result of the determining; providing the usage information to the source base station in response to the received request. According to a third aspect of the invention, there is provided an apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform monitoring if a request to provide a support information is received from a source base station, wherein the support information indicates if a mobile edge computing application is supported at a target base station; requesting to provide a capability information from a target mobile edge computing platform, wherein the capability information indicates if the target mobile edge computing platform supports the mobile edge computing application; preparing the support information based on the capability information; providing the support information to the source base station in response to the received request.

According to a fourth aspect of the invention, there is provided an apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform monitoring if a request to provide a capability information is received from a target base station, wherein the capability information indicates if a target mobile edge computing platform supports a first mobile edge computing application; determining if the target mobile edge computing platform supports the first mobile edge computing application; preparing the capability information based on a result of the determining; providing the capability information to the target base station in response to the received request.

According to a fifth aspect of the invention, there is provided an apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform providing a list of one or more target base stations from a source base station to a mobile edge computing platform, wherein a terminal connected to the source base station may handover to each of the one or more target base stations with a probability larger than a predefined threshold. According to a sixth aspect of the invention, there is provided an apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform monitoring if a list of one or more target base stations is received by a source mobile edge computing platform; determining one or more target mobile edge computing platforms, wherein each of the target mobile edge computing platforms corresponds to respective at least one of the one or more target base stations if the list is received; checking, if the list is received, if a terminal uses a mobile edge computing application of the source mobile edge computing platform; providing at least one of an application context and a user context of the application used by the terminal to each of the target mobile edge computing platforms if the terminal uses the mobile edge computing application. According to a seventh aspect of the invention, there is provided a method, comprising inquiring, from a source mobile edge computing platform, a usage information for a terminal indicating a mobile edge computing application of the source mobile edge computing platform used by the terminal; requesting, from a target base station, a support information indicating if the mobile edge computing application is supported at the target base station; deciding on a handover of the terminal to the target base station based on the usage information and the support information. According to an eighth aspect of the invention, there is provided a method, comprising monitoring if a request to provide a usage information for a terminal indicating a mobile edge computing application of a source mobile edge computing platform used by the terminal is received from a source base station; determining if the terminal uses the mobile edge computing application; preparing the usage information based on a result of the determining; providing the usage information to the source base station in response to the received request.

According to a ninth aspect of the invention, there is provided a method, comprising monitoring if a request to provide a support information is received from a source base station, wherein the support information indicates if a mobile edge computing application is supported at a target base station; requesting to provide a capability information from a target mobile edge computing platform, wherein the capability information indicates if the target mobile edge computing platform supports the mobile edge computing application; preparing the support information based on the capability information; providing the support information to the source base station in response to the received request.

According to a tenth aspect of the invention, there is provided a method, comprising monitoring if a request to provide a capability information is received from a target base station, wherein the capability information indicates if a target mobile edge computing platform supports a first mobile edge computing application; determining if the target mobile edge computing platform supports the first mobile edge computing application; preparing the capability information based on a result of the determining; providing the capability information to the target base station in response to the received request. According to an eleventh aspect of the invention, there is provided a method, comprising providing a list of one or more target base stations from a source base station to a mobile edge computing platform, wherein a terminal connected to the source base station may handover to each of the one or more target base stations with a probability larger than a predefined threshold. According to a twelfth aspect of the invention, there is provided a method, comprising monitoring if a list of one or more target base stations is received by a source mobile edge computing platform; determining one or more target mobile edge computing platforms, wherein each of the target mobile edge computing platforms corresponds to respective at least one of the one or more target base stations if the list is received; checking, if the list is received, if a terminal uses a mobile edge computing application of the source mobile edge computing platform; providing at least one of an application context and a user context of the application used by the terminal to each of the target mobile edge computing platforms if the terminal uses the mobile edge computing application. Each of the methods of the seventh to twelfth aspect may be a method of mobile edge computing.

According to a thirteenth aspect of the invention, there is provided a computer program product comprising a set of instructions which, when executed on an apparatus, is configured to cause the apparatus to carry out the method any of the seventh to twelfth aspects. The computer program product may be embodied as a computer-readable medium or directly loadable into a computer.

Further details are set out in the dependent claims.

According to some embodiments of the invention, at least one of the following advantages may be achieved:

• Service drops at handover are minimized;

• Robustness of MEC handovers is improved;

· Operability of the overall system including radio network and MEC platforms is improved;

• Mission critical use cases may be supported; and

• Quality of MEC relocation groups may be improved. It is to be understood that any of the above modifications can be applied singly or in combination to the respective aspects to which they refer, unless they are explicitly stated as excluding alternatives. Brief description of the drawings

Further details, features, objects, and advantages are apparent from the following detailed description of the preferred embodiments of the present invention which is to be taken in conjunction with the appended drawings, wherein:

Fig. 1 shows a principle of handover of a UE from a source BTS with an associated MEC platform running a MEC application to a target BTS with its associated MEC platform running the MEC application;

Fig. 2 shows a method to evaluate the status of the MEC system (according to some embodiments of the invention;

Fig. 3 shows a method to prepare the handover of the MEC application according to some embodiments of the invention;

Fig. 4 shows a situation where a handover of the MEC application fails;

Fig. 5 shows a method to prepare the handover of the MEC application including pre-emption according to some embodiments of the invention;

Fig. 6 comprising Figs. 6a and 6b shows a method to execute the handover of the MEC application according to some embodiments of the invention;

Fig. 7 shows an apparatus according to an embodiment of the invention;

Fig. 8 shows a method according to an embodiment of the invention;

Fig. 9 shows an apparatus according to an embodiment of the invention;

Fig. 10 shows a method according to an embodiment of the invention;

Fig. 1 1 shows an apparatus according to an embodiment of the invention;

Fig. 12 shows a method according to an embodiment of the invention;

Fig. 13 shows an apparatus according to an embodiment of the invention;

Fig. 14 shows a method according to an embodiment of the invention;

Fig. 15 shows an apparatus according to an embodiment of the invention;

Fig. 16 shows a method according to an embodiment of the invention;

Fig. 17 shows an apparatus according to an embodiment of the invention;

Fig. 18 shows a method according to an embodiment of the invention; and

Fig. 19 shows an apparatus according to an embodiment of the invention. Detailed description of certain embodiments

Herein below, certain embodiments of the present invention are described in detail with reference to the accompanying drawings, wherein the features of the embodiments can be freely combined with each other unless otherwise described. However, it is to be expressly understood that the description of certain embodiments is given by way of example only, and that it is by no way intended to be understood as limiting the invention to the disclosed details. Moreover, it is to be understood that the apparatus is configured to perform the corresponding method, although in some cases only the apparatus or only the method are described.

According to some embodiments of the invention, the handover of the UE from the instance of the MEC application running on the MEC platform associated with the source BTS to the instance of the MEC application running on the MEC platform associated with the target BTS may be handled transparently by the same, distributed, de-central mechanisms as the handover of voice calls and data traffic. That is, the mobility management of the MEC applications is integrated in the mobility management of the mobile network.

In the present patent application, these handovers are distinguished as "handover of the UE (terminal)" related to the conventional 3GPP handover of a terminal from a source cell to a target cell, typically reacting on radio conditions, and "handover of the MEC application" related to handing over the context (user context and/or application context) of the application for the terminal from one MEC platform to another MEC platform.

Evaluation of status of MEC system

According to some embodiments of the invention, the source BTS may collect for each UE the status of the associated MEC Platform and MEC Applications from each potential target BTS to consider the status of the potential target MEC Platform and MEC Applications for the decision on target and time of handover. For example, the source BTS may decide not to handover the UE to a specific target BTS not supporting the MEC application used by the UE on the source BTS, even though the radio conditions for the UE on the specific target BTS may be better than those on other target BTSs. In the context of the present application, the terms "base station" or "BTS" may not include the "pure" base station but may include some control portion, too. For example, in 2G and 3G, the terms "base station" or "BTS" may include not only the BTS and NodeB (or the radio control portion thereof), respectively, but also a portion of or the entire associated BSC and RNC, respectively. The portion may be in particular the portion responsible for handover control. On the other hand, in 4G and 5G, the terms "base station" or "BTS" may comprise an entire eNB or a portion thereof (in particular: radio control portion and handover control portion).

Fig. 2 shows a method to evaluate the status of the MEC system (MEC platform and MEC application) according to some embodiments of the invention. This method may be performed while the UE is still attached to the source BTS (before handover). The following steps are performed:

1 . ) The source BTS interrogates from its associated MEC platform the MEC applications (services), that a given UE uses ("usage information").

2. ) The MEC Platform replies the services that the UE uses

3. ) The source BTS interrogates from its neighbouring BTSs, whether their associated MEC platforms are able to run the requested MEC applications (i.e. the MEC applications used by the UE). For example, the source BTS may interrogate the neighbouring BTS via X2 interface or via S1 interface.

4. ) The neighbouring BTSs query their associated MEC platforms whether they are able to run the requested MEC application (in other words: whether or not they support the requested MEC applications).

5. ) The MEC platforms deliver the information ("capability information") to their associated BTSs

6. ) The neighbouring BTSs deliver the information ("support information") to the source

BTS. Typically, the content of the support information is the same as that of the capability information. However, for example, the pieces of information may be differently formatted or provided according to a different protocol. In some embodiments, the neighbouring BTS may filter the capability information from the MEC platform such that the support information to the source BTS indicates a smaller capability than the capability information. In some embodiments, the neighbouring BTS may combine capability information from plural MEC platforms to which the neighbouring BTS is associated into the support information.

7.) Additionally to the currently available information the source BTS evaluates the status of the MEC system to determine target and time of a handover. For example, the source BTS may exclude a BTS not supporting a MEC application used by the

UE as a handover candidate for the UE. As another example, the source BTS may decide that UEs not using a certain MEC application preferably handover to a target BTS not supporting this MEC application, thus leaving capacity on MEC platforms providing this MEC application for UEs using this MEC application.

8.) Optionally: The source BTS informs its associated MEC Platform about the handover. The currently proposed ETSI MEC RNIS interface supports this step.

Hence, according to some embodiments of the invention, the interface between BTS and associated MEC platform (RNIS) and the interface between source and target BTS may be enhanced the following way:

Enhancement of the interface BTS C-Plane - MEC (MEC RNIS)

ETSI MEC already has proposed an interface between the control plane of the BTS and the MEC platform (Radio Network Information Service, RNIS). According to ETSI MEC the MEC platform shall be enabled to collect from the BTS information regarding handovers. The MEC platform and MEC applications shall use this information to manage the mobility of MEC applications. This is sufficient for the concept of "MEC follows radio". In order to integrate the mobility of MEC into the mobility management of the radio network according to some embodiments of the invention, the interface may provide information in the opposite direction. I.e. BTS collects information about the status and availability of the MEC platform and its applications. By using this enhanced interface

• A source BTS requests information from its associated MEC platform about the applications that a given UE is using from the MEC platform. • A potential target BTS requests information about the capabilities of its associated MEC platform ("target MEC platform) and the status of requested applications. For example:

o Does the MEC platform support a given application?

o Is the application already running?

o Within which timeframe would the MEC platform be able to instantiate a requested application?

o How loaded is the MEC platform and the requested application? o Would the MEC platform accept the additional UE for the service?

Enhancement of the interfaces between source and target BTS

Before performing the handover the source BTS collects various information from each potential target BTS to evaluate potential targets and to plan the handover. According to some embodiments of the invention, these interfaces may be enhanced to enable the source BTS to interrogate information about the MEC platform associated with the neighbouring BTS via standardized interfaces.

E.g., in current LTE, the eNB are using the X2 interface (3GPP TS 36.423) and S1 interface (3GPP TS 36.413) to control the handover. The eNB may use these interfaces to query information about the capabilities and status of the target, e.g. to perform inter-eNB load balancing or inter-eNB coordinated Power Saving.

To enable the source BTS to evaluate the status of the MEC platform associated with a potential target BTS, according to some embodiments of the invention, the interfaces between the BTSs may be enhanced. For example:

• The source eNB interrogates from the potential target eNBs certain information about the status of these MEC application(s) that UEs in the source cells are using

• The target eNB must be able to send information about the capabilities of the associated MEC platform and its status. E.g.:

o Does the MEC platform support a given application?

o Is the application already running? o Within which timeframe would the MEC platform be able to instantiate a requested application?

o How loaded is the MEC platform and the requested application? Would the target accept additional UE for the service?

According to some embodiments, source and target BTS may query the information case by case for each UE that shall perform handover. According to some embodiments, the BTS may maintain a map about the status of the MEC platforms of neighbouring BTS. BTS might embed this status transfer in the regular messages about the cell state and cell configurations. BTS might collect this information as part of the "automatic neighbour relationship" establishment.

In the same manner, the interfaces between different radio technologies may be enhanced, e.g. the interface for "Radio Information Management" (RIM) between LTE and UTRAN. Newly defined interfaces between the BTS as e.g. for 5G may be designed to offer the corresponding functions right from the start

According to some embodiments, the source BTS considers the status of the MEC system associated with the target BTS for its handover decision. That is, the algorithms in the BTS that evaluate the environment of the UE, that determine the target cells, and that decide on the handover may consider the status of the MEC computing system for its decisions on handover. I.e., the source BTS may consider which services the UE uses in the MEC platform associated with the source BTS, and whether these services are available at the target. In addition, it may consider which QoS the target offers for this service, etc. These algorithms intentionally are not standardized by 3GPP.

Currently, the source BTS evaluates the measurements reports from the UE, the availability of the links to the target cells, the load of the target cells, capabilities of the UE, and/or several other quantities to select the best target and time for a handover. Currently the source BTS has no access to any status of the MEC system and thus is not able to consider the status of MEC for the handover decision.

According to some current approaches, the MEC system defines its own mobility management, where the mobility of MEC is planned (and according to the architecture has to) follow the decision of the BTS. In worst case the BTS initiates a handover towards a target that is not associated to any MEC Platform at all. In this case, MEC is not able to do any corrective action and the UE will be dropped from service. By introduction of an architecture that enables the BTS to take the status of the MEC system into account for its HO decision, the BTS may optimize the handover to guarantee a seamless service by MEC Applications across handovers. This will improve the robustness of handovers within the MEC system, because the BTS might avoid handovers to BTS that are not able to provide the requested MEC Application with the requested level of service.

This also might improve the mechanisms of finding neighbour relations automatically ("ANR"), because ANR also would consider the status of MEC Applications. Therefore the handovers within the MEC system would benefit from the already available ANR mechanisms of the mobile network.

Preparation of MEC handover

According to some embodiments of the invention, the preparation of the handover within the MEC system may be part of the regular preparation of the handover in the mobile network. Thus, the handover of the MEC application may be controlled by the BTS. In some embodiments, it may be handled via the existing inter-BTS connections within the mobile network (e.g. in LTE: S1 or X2 interface).

Fig. 3 shows a method to prepare the handover of the MEC application according to some embodiments of the invention. This method may be performed while the UE is still attached to the source BTS (before handover). The following steps are performed:

1 . ) The source BTS defines a proper target for handover for a given UE. The target

MEC platform is able to instantiate these MEC applications, that the UE requires. This step may be performed as described in section "Evaluation of status of MEC system" hereinabove.

2. ) The source BTS may inform the target BTS about a planned handover of an UE that is using a specific MEC application. 3. ) The target BTS may request its associated MEC platform ("target MEC platform") to prepare the requested application.

4. ) The target MEC platform may prepare the requested MEC applications. For example:

a. If the application is not already running, then the MEC platform may instantiate it;

b. If the application is not available at the target MEC platform, then the MEC platform may load it from a repository.

5. ) Target MEC platform may inform the associated BTS about the result of preparation ("provision success information").

6. ) The target BTS may inform the source BTS about the result of the preparation

("preparation success information"). Typically, the preparation success information may be the same as the provision success information. However, for example, the target BTS may filter some positive results from the provision success information such that the preparation success information has less positive results. As another example, the target BTS may combine provision success information from plural associated MEC platforms into a single preparation success information.

7. ) If the preparation has succeeded, the source BTS may optionally inform its associated MEC Platform about the successful preparation of a handover.

In case the preparation has failed, the source BTS might consider a different target for the handover in order to guarantee to the UE a seamless service by the MEC applications. The final result of this decision depends on the details of the handover algorithms. In some embodiments, source BTS may also inform its associated MEC Platform ("source MEC platform") on the planned handover in order to prepare the source MEC platform on the handover. E.g. such information may be provided in step 2. In some embodiments, target MEC platform may inform the source MEC platform accordingly, e.g. in step 5. For example, target MEC platform may inform MEC platform on handover preparation via a link through the MEC system (not via the base stations).

In some embodiments, step 5 and/or step 6 (providing provision/preparation success information) may be omitted. For example, they may be omitted if the target BTS and/or source BTS trust that the preparation will be successful. In some embodiments, step 1 (defining a proper target for handover able to instantiate these MEC applications required by the UE) may be omitted. For example, it may be omitted if all MEC platforms of the network provide the same MEC applications and surely have sufficient capacity. As another example, step 1 may be omitted if a certain rate of service drops at handover is acceptable.

If step 1 is omitted, some embodiments of the invention provide: Source eNB or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

inquiring, from a source mobile edge computing platform, a usage information indicating if a terminal uses a mobile edge computing application of the source mobile edge computing platform;

providing a preparation request to a target base station if it is decided that the terminal is handed over to the target base station and the usage information indicates that the terminal uses the mobile edge computing application, wherein the preparation request informs the target base station that it is decided that the terminal is handed over to the target base station and that the terminal uses the mobile edge computing application.

Target BTS or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a preparation request is received from a source base station, wherein the preparation request informs that a terminal is to be handed over to a target base station and that the terminal uses a mobile edge computing application;

requesting a target mobile edge computing platform associated to the target base station to prepare for providing the mobile edge computing application to the terminal.

Target MEC platform or component thereof: Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a request to provide a capability information is received from a target base station, wherein the capability information indicates if the target mobile edge computing platform supports a first mobile edge computing application;

monitoring if a target mobile edge computing platform receives a request to prepare for providing a mobile edge computing application to a terminal;

preparing the providing of the mobile edge computing application to the terminal by the target mobile edge computing platform if the request to prepare is received.

In some embodiments, the preparation of the handover of the MEC application may be closely linked to the handover of the UE. For example, the target BTS may prepare radio resources for the terminal upon receipt of the preparation request from the source BTS. If the provision success information is not received from the MEC platform, it may dismantle the radio resources for the terminal. Alternatively, the target BTS may not prepare the radio resources for the terminal until the provision success information is received from the MEC platform. Hence, according to some embodiments of the invention, the interface between BTS and MEC platform (RNIS) as well as the interface between the BTS (in LTE: X2 and/or S1 ) is enhanced.

Enhancement of the interface between BTS control plane and MEC (MEC RNIS)

According to some embodiments of the invention, the enhanced interface allows the (target) BTS to request from the associated MEC platform to instantiate a set of requested MEC applications. As reply the MEC platform may inform the BTS about the result of the instantiation.

By using this enhanced interface

• The BTS may request from the associated MEC platform to instantiate a set of MEC applications. • The MEC platform may inform the BTS about the result of the instantiation of MEC applications.

Enhancement of the interfaces between source and target BTS

In some embodiments of the invention, the interfaces that source BTS and target BTS are using to prepare and control the handover (e.g. LTE: X2 or S1 ) may be enhanced to enable the target BTS to prepare its associated MEC platform via standardized interfaces and procedures as follows:

· The source BTS requests from the target BTS to instantiate a set of MEC applications in its associated MEC platform.

• The target BTS informs to the source BTS about the result of the instantiation of MEC applications in the associated MEC platform. Currently the source BTS prepares the handover to a target BTS without considering the status and capabilities of the related MEC system. The BTS might prepare a handover which from radio and core perspective would be fine, but that from MEC perspective would fail. By introduction of an architecture that enables the BTS to control the preparation of the overall handover, including the handover within the MEC system, the robustness of handovers within the MEC system will be improved.

By using the already available and established inter-BTS links the robustness of the handover preparation will be further increased, especially because these links usually are closely monitored. In addition, the operability of the overall system would be improved, because the mobility within the MEC system would be based on the same planned, managed, and secured links as the mobility within the mobile network.

Pre-emption

If the MEC Platform associated to the target BTS is not able to instantiate the requested MEC Application because the resources of the target MEC Platform are exhausted by already running applications, then the mobile network may handover the UE into the target cell, but the UE will not be able to use the service by the corresponding MEC Application. This might cause severe problems for mission critical applications like semi-autonomous (remote-controlled) driving, tele-medicine, or any other mission-critical communication.

Such a situation is depicted in Fig. 4 as an example, where the UE uses MEC application 1 at the source BTS. However, the target MEC platform at the target BTS is exhausted by other MEC applications such that the UE, if handed over to the target BTS, cannot use the MEC application 1 (at least not with a required QoS).

According to some embodiments of the invention, the preparation of the handover of a high priority MEC application may pre-empt low priority MEC applications running on the target MEC platform. Thus, a continuous service with a sufficient QoS may be guaranteed for the high priority application at handover. An example of a typical high priority application is a Tsunami or Earthquake warning application.

Fig. 5 shows a method to prepare the handover of the MEC application including preemption according to some embodiments of the invention. This method may be performed while the UE is still attached to the source BTS (before handover). The following steps are performed:

1 . ) Source MEC Platform informs the target MEC Platform that the UE requires a high- priority MEC Application.

2. ) The target MEC Platform instantiates the high-priority MEC Application. To do so, the MEC Platform might drop lower-priority MEC Applications, if necessary.

3. ) The target MEC Platform informs the source MEC Platform about the result of the pre-emption request. This step may be omitted, e.g. if the source MEC platform trusts on the success of the pre-emption at the target MEC platform.

If the target MEC Platform is nevertheless not able to instantiate the high-priority MEC Application, it may inform the source MEC platform and/or the source BTS thereon. Thus, in some embodiments of the invention, the source BTS may consider if another target BTS able to provide, with its associated MEC platform, the high-priority MEC application is available for the handover. In some embodiments, the source MEC platform may determine the priority of each application according to a predetermined table. The priority may depend not only on the application but also on the UE (e.g. the type of terminal). In these embodiments, the Source MEC platform has to inform target MEC platform on the priority, preferably via the source BTS and the target BTS.

In some embodiments, the target MEC platform may determine the priority of each ME application, e.g. based on a predefined table. In these cases, the priority need not to be transmitted from the source MEC platform to the target MEC platform. Instead, the target MEC platform determines the priority when a request to prepare for a handover of the MEC application is received. In these embodiments, pre-emption may always be active, or it may be activated based on a request e.g. from the source MEC platform or the source BTS. In some embodiments, the priority may be determined at both the source MEC platform and the target MEC platform. The predefined tables in the source MEC platform and the target MEC platform may be the same or different from each other. In case of a conflict, a prevalence may be decided based on a predefined rule. For example, the table at the target MEC platform may have prevalence over the table at the source MEC platform; or, if the priorities for a MEC application are different according to the two tables, the higher priority has prevalence; etc.

According to some embodiments, the interfaces between MEC Platforms may be enhanced such that the source MEC Platform is able to inform the target MEC Platform about the priority of the MEC Application which is subject of the handover. The target MEC Platform may react in a well-defined manner and either accept or reject the request. If the target MEC Platform accepts the request, it means that the target is able to instantiate the requested MEC Application within a given time frame with a given level of service (QoS). In order to provide the priority information, interfaces of the MEC system between MEC Platforms as well as the inter-BTS interfaces of regular mobility management in the mobile network may be used. The providing of the priority information may be considered as a request for pre-emption. If the priority information is provided via interfaces of the MEC system, the source MEC platform has to be informed on the target MEC platform. For example, information on the target MEC platform may be provided by step 7 of the preparation of MEC handover described hereinabove.

The request for pre-emption might be part of the handover preparation. For example, the handover preparation may be performed as described hereinabove. However, in some embodiments, the source MEC platform may request pre-emption if it is informed that a handover of the UE to a target BTS is planned. For example, the handover may be planned based on conventional handover preparation without taking into account that the UE uses a MEC application.

In such cases, embodiments of the invention provide, for example: Source MEC platform or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a handover information is received, wherein the handover information informs that a terminal is planned to be handed over to a target base station;

checking if the terminal uses a mobile edge computing application;

determining a priority of the mobile edge computing application;

determining a target mobile edge computing platform associated to the target base station;

providing an indication of the priority to the target mobile edge computing platform if the handover information is received and the terminal uses the mobile edge computing application.

Target MEC platform or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a target mobile edge computing platform receives a handover request to prepare for providing a first mobile edge computing application to a terminal;

monitoring if the target mobile edge computing platform receives a pre-emption request to apply pre-emption with respect to the providing of the first mobile edge computing application to the terminal; checking if a first priority of the first mobile edge computing application is higher than a second priority of a second mobile edge computing application used on the target mobile edge computing platform,

stopping the usage of the second mobile edge computing application on the target mobile edge computing platform if the first priority is higher than the second priority, the handover request is received, and the pre-emption request is received.

In some embodiments of the invention, the target BTS may provide an identification of the target MEC platform to the source BTS. For example, the target BTS may provide the identification while evaluating the status of the MEC system and/or at preparation of handover. Source BTS may then inform source MEC platform on the identification of the target MEC platform. Thus, source MEC platform is aware of the identification of the target MEC platform and may provide the priority information to the target MEC platform. In some embodiments, the source MEC platform may determine the target mobile edge computing platform based on an association table available to the source MEC platform. The association table indicates which MEC platform(s) are associated to which base station(s). It may be stored in one, some, or all of the MEC platforms of the network or separately therefrom.

Pre-emption of MEC Applications at the target MEC Platform based on the priority of MEC Applications enables to use MEC applications for mission critical use cases. Otherwise the coverage by the MEC Application cannot be predicted, which might lead to service interruption with serious consequences.

Execution of MEC handover

According to some embodiments of the invention, the execution of the handover within the MEC system may be part of the regular execution of the handover in the mobile network. Thus, the execution may be controlled by the BTS. It may be handled via the existing inter- BTS connections within the mobile network (e.g. in LTE: S1 and X2).

Fig. 6 comprising Figs. 6a and 6b shows a method to execute the handover of the MEC application according to some embodiments of the invention. This steps of Fig. 6a may be performed while the UE is still attached to the source BTS (before handover). The following steps are performed:

1 . ) Precondition: The BTS has defined a proper target for handover for a given UE and successfully prepared the MEC application at the MEC platform associated with the target BTS. For example, the precondition may be fulfilled by the Evaluation of status and Preparation of the MEC handover described hereinabove. As a further typical precondition, the source MEC platform may be informed about the handover, too.

2. ) The source BTS may inform its associated MEC platform and the selected target

BTS about the execution of the handover.

3. ) The target BTS may request its associated MEC platform ("target MEC platform") to execute the handover.

4. ) The source MEC platform and target MEC platform create a connection to each other using the same logical interface that the source BTS and target BTS are using for controlling the handover (in LTE: X2 or S1 ).

5. ) Source and target MEC platform and MEC application instances exchange all information that is necessary for the specific applications to transfer the application context and/or user context ("context") and to execute a handover for the specific UE. The details of such communication are specific for the specific applications.

6. ) UE has performed handover in mobile network and in MEC system

In case any part of the execution fails, the source BTS may consider a different target for the handover to guarantee to the UE a seamless service by the MEC applications. The final result of this decision depends on the details of the handover algorithms.

Hence, according to some embodiments of the invention, the interface between BTS and MEC platform (RNIS) as well as the interface between the BTSs (in LTE: X2 and/or S1 ) is enhanced.

Enhancement of the interface between BTS control plane and MEC (MEC RNIS)

To enable the BTS to execute handover of MEC applications, the interface between BTS and MEC platform may be enhanced as follows: • The source BTS may request from its associated MEC platform to execute the handover to the target MEC application instance(s).

• The source BTS may offer to its associated MEC platform a generic tunnelling connection via the regular mobility management interfaces towards the target MEC platform.

o Alternative: The MEC platform at source BTS may request from source BTS a generic tunnelling connection via the regular mobility management interfaces towards the target MEC platform.

• The target BTS may request from its associated MEC platform to execute the handover of the UE from the source MEC application instances.

• The target BTS may offer to its associated MEC platform a generic tunnelling connection via the regular mobility management interfaces towards the source MEC platform.

o Alternative: The MEC platform at target BTS may request from target BTS a generic tunnelling connection via the regular mobility management interfaces towards the source MEC platform.

Enhancement of the interfaces between source BTS and target BTS Source BTS and target BTS may use standardized interfaces (in LTE: X2 and S1 ) to execute the handover of voice calls and data transfers.

To enable the source BTS to execute the handover of the MEC applications towards the target MEC platform at the potential target BTS, the interfaces between the BTS may be enhanced.

• The source BTS may request the selected target BTS to execute the handover of the MEC application.

• The source BTS may open a generic tunnelling interface towards the target BTS via the standardized mobility management interfaces. The detailed content and format of the data is defined by the applications; from BTS point of view it is just "data".

o Alternative: The target BTS may open a generic tunnelling interface towards the source BTS via the standardized mobility management interfaces In the source BTS, the tunnel between source BTS and source MEC platform and the tunnel between source BTS and target BTS may be connected. In the target BTS, the tunnel between target BTS and target MEC platform and the tunnel between target BTS and source BTS may be connected. Thus, a tunnel between source MEC platform and target MEC platform is created such that the handover of the MEC application is transparent to the source BTS and the target BTS.

In some embodiments of the invention, step 1 (deciding on a proper target BTS, and/or preparing the handover, both in view of the MEC application the UE is using, and/or informing the source MEC platform on the planned handover) may be omitted. That is, the source BTS may decide on the target BTS and/or prepare the handover thereto without considering that the UE uses a MEC application of the source MEC application platform, which should be handed over to the target MEC application, too. For example, such embodiments may be employed if a certain rate of service drops is acceptable.

In some embodiments of the invention, the source MEC platform may handover the context of the used MEC application not via the base stations (through the tunnel) but within the MEC system. In such embodiments, the handover of the MEC application context is controlled via the link between the base stations, but the handover of the context is performed by a different interface between the MEC platforms. In such embodiments, the tunnel between source MEC platform and target MEC platform via the base stations is not needed and may not be set up.

If step 1 is omitted, some embodiments of the invention provide for example (several alternatives for each of the source BTS, source MEC platform, target BTS, and target MEC platform):

Source BTS or component thereof: Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if it is decided that a terminal is handed over from a source base station to a target base station; requesting a source mobile edge computing platform to handover a context of a mobile edge computing application used by the terminal to a target mobile edge computing platform associated to the target base station if it is decided that the terminal is handed over from the source base station to the target base station.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

controlling the handover of the terminal from the source base station to the target base station via a handover control interface;

opening a base station tunnel from the source base station via the handover control interface to the target base station,

opening a source tunnel from the source base station to the source mobile edge computing platform;

connecting the source tunnel and the base station tunnel in the source base station.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

controlling the handover of the terminal from the source base station to the target base station via a handover control interface;

opening a base station tunnel from the source base station via the handover control interface to the target base station,

accepting a source tunnel from the source mobile edge computing platform to the source base station;

connecting the source tunnel and the base station tunnel in the source base station.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

controlling the handover of the terminal from the source base station to the target base station via a handover control interface;

accepting a base station tunnel from the target base station via the handover control interface to the source base station;

opening a source tunnel from the source base station to the source mobile edge computing platform;

connecting the source tunnel and the base station tunnel in the source base station. The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

controlling the handover of the terminal from the source base station to the target base station via a handover control interface;

accepting a base station tunnel from the target base station via the handover control interface to the source base station;

accepting a source tunnel from the source mobile edge computing platform to the source base station;

connecting the source tunnel and the base station tunnel in the source base station.

Source MEC platform or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a source mobile edge computing platform receives, from a source base station, a request to provide a context of a mobile edge computing application for a terminal to a target mobile edge computing platform ;

providing the context of the mobile edge computing application for the terminal to the target mobile edge computing platform if the request is received.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

opening a source tunnel from the source mobile edge computing platform to the source base station if the request to handover the mobile edge computing application is received; wherein

the context is provided to the target mobile edge computing platform via the source tunnel.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

accepting a source tunnel from the source base station to the source mobile edge computing platform if the request to provide the context is received; wherein

the context is provided to the target mobile edge computing platform via the source tunnel. Target BTS or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a target base station receives, from a source base station, a request to handover a context of a mobile edge computing application for a terminal;

requesting a target mobile edge computing platform to provide the mobile edge computing application to the terminal using the context for the terminal if the request to handover the mobile edge computing application is received.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

monitoring if a handover of the terminal from the source base station to the target base station is controlled via a handover control interface;

opening a base station tunnel from the target base station via the handover control interface to the source base station if the request to handover the context of the mobile edge computing application is received;

opening a target tunnel from the target base station to the target mobile edge computing platform if the request to handover the context of the mobile edge computing application is received;

connecting the target tunnel and the base station tunnel in the target base station.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

monitoring if a handover of the terminal from the source base station to the target base station is controlled via a handover control interface;

accepting a base station tunnel from the source base station via the handover control interface to the target base station if the request to handover the context of the mobile edge computing application is received;

opening a target tunnel from the target base station to the target mobile edge computing platform if the request to handover the context of the mobile edge computing application is received;

connecting the target tunnel and the base station tunnel in the target base station. The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

monitoring if a handover of the terminal from the source base station to the target base station is controlled via a handover control interface;

opening a base station tunnel from the target base station via the handover control interface to the source base station if the request to handover the context of the mobile edge computing application is received;

accepting a target tunnel from the target mobile edge computing platform to the target base station if the request to handover the context of the mobile edge computing application is received;

connecting the target tunnel and the base station tunnel in the target base station.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

monitoring if a handover of the terminal from the source base station to the target base station is controlled via a handover control interface;

accepting a base station tunnel from the source base station via the handover control interface to the target base station if the request to handover the context of the mobile edge computing application is received;

accepting a target tunnel from the target mobile edge computing platform to the target base station if the request to handover the context of the mobile edge computing application is received;

connecting the target tunnel and the base station tunnel in the target base station.

Target MEC platform or component thereof:

Apparatus, comprising at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform

monitoring if a target mobile edge computing platform receives, from a target base station, a request to provide a mobile edge computing application to a terminal;

obtaining a context of the mobile edge computing application for the terminal from a source mobile edge computing platform; providing the mobile edge computing application to the terminal based on the obtained context.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

opening a target tunnel from the target mobile edge computing platform to the target base station if the request is received; wherein

the context of the mobile edge computing application for the terminal is obtained through the target tunnel.

The at least one processor, with the at least one memory and the computer program code, may be arranged to cause the apparatus to further perform

accepting a target tunnel from the target base station to the target mobile edge computing platform if the request is received; wherein

the context of the mobile edge computing application for the terminal is obtained through the target tunnel.

In principle, the MEC applications might use a different, private, MEC-specific connection that circumvents the standardized mobility interfaces. But the usage of the standardized interfaces offers the advantage, that MEC would be able to rely on the management, supervision, and security of this already existing connection. In addition, the operability of the overall system would be improved, because the mobility within the MEC system would be based on the same planned, managed, and secured links as the mobility within the mobile network.

Currently the source BTS executes the handover to a target BTS without considering the status of the related MEC system. The BTS might execute a handover which from radio and core perspective would be fine, but that from MEC perspective fails. However, the BTS would not be aware of this and would not be able to react. By introduction of an architecture that enables the BTS to control the execution of the overall handover, including the handover within the MEC system, the robustness of handovers within the MEC system will be improved.

Proposing MEC relocation group According to the plans of ETSI MEC, the MEC system shall maintain a list of potential targets for MEC handover ("Relocation Group") in order to improve the mobility within the overall MEC system. According to ETSI GR MEC-018, VO.2.4, all MEc platforms of the relocation group may be provided with user and application information ("context"), so that a handover of the MEC application from one MEC platform to another MEC platform of the relocation group may be performed quickly.

However, the MEC system only has very limited knowledge about the radio conditions, which in the end will determine the actual handover time and target.

On the other hand, the BTS of the various radio technologies have very sophisticated mechanisms for the mobility management. Before performing the handover of a UE, the source BTS collects and evaluates various information from the UE and from the potential target BTS to determine the best handover target and best time for a handover. The mobility management of current mobile networks are offering mechanisms to find the neighbour relations automatically ("ANR"). In addition the BTS maintains statistics on the performance of the executed or failed handovers. As a consequence the BTS has the best knowledge about the overall performance and probabilities of handovers to all targets, that from radio point of view might be accessible.

Therefore, according to some embodiments of the invention, the source BTS may compile a list of target cells and/or target BTS and pass this list as proposed "Relocation Group" to the MEC Platform. The list may comprise a ranking of the cells and/or target BTS. The list may comprise only those cells and/or target BTS, for which a probability of a handover of a UE handing over from the source BTS to the respective cell and/or target BTS is higher than a predefined threshold. For example, such probability may be evaluated from handover statistics of the past. The MEC system (e.g. source MEC platform associated to the source BTS) may consider the proposal of the source BTS and build the MEC relocation group based on the list received from the source BTS. For example, the MEC relocation group may be the same as the MEC platforms corresponding to the cells and/or target BTS of the received list. The source MEC platform may add further MEC platforms or remove some of the MEC platforms of the list, e.g. the MEC platforms associated to lower ranked cells/target BTS. The source MEC platform may determine the mobile edge computing platform(s) corresponding to the cells/target BTS of the list based on an association table available to the source MEC platform. The association table indicates which MEC platform(s) are associated to which base station(s). It may be stored in one, some, or all of the MEC platforms of the network or separately therefrom. Alternatively, the list from the source base station may comprise an identification of the target MEC platform instead of or in addition to the identification of the cells/target BTS. The list of BTS may comprise further information for some or all of the BTS such as number of HO per time window, quality of HO, failure rate of handover etc.

Enhancement of ETSI MEC RNIS interface to transfer "Relocation Groups" To enable the BTS to propose a "Relocation Group" to the MEC Platform, the ETSI MEC RNIS interface may be enhanced in the following way:

The BTS may be able to send a list of potential target cells and target BTS as "Proposed Relocation Group" to the MEC Platform. The BTS may include quality criteria for each potential target cell and target BTS of the "Proposed Relocation Group". The list may be ranked. Instead of or in addition to the identifiers of the cells / target BTS, the list may comprise identifiers of the MEC platforms associated to the respective cells/BTS.

In some embodiments, the MEC Platform may request the list (proposed relocation group(s)) from the BTS. In some embodiments, the BTS may initiate the transfer of the list to the MEC platform.

Compared to the MEC Platform, the BTS has a much more detailed knowledge on the potential target cells and the corresponding quality and performance of handovers, because the BTS in detail evaluates many properties of the UE, the air interface, the neighbour cells and neighbour BTS. Due to ANR mechanisms the mobile network is able to automatically detect this neighbour information in a very early phase of the lifetime of the BTS without manual intervention. Therefore, the quality of "Relocation Groups" will be much better if the BTS would assist in generating them and would offer proposals. Likewise the robustness and quality of handovers in the MEC system would be improved. Some embodiments of the invention provide any arbitrary combination of two or more of the Evaluation of status of MEC system, Preparation of MEC handover, Pre-emption, Execution of MEC handover, and Proposing MEC relocation group, as described hereinabove. Fig. 7 shows an apparatus according to an embodiment of the invention. The apparatus may be a base station such as a source base station (NodeB, eNB, etc.) or an element thereof. Fig. 8 shows a method according to an embodiment of the invention. The apparatus according to Fig. 7 may perform the method of Fig. 8 but is not limited to this method. The method of Fig. 8 may be performed by the apparatus of Fig. 7 but is not limited to being performed by this apparatus.

The apparatus comprises inquiring means 10, requesting means 20, and deciding means 30. Each of the inquiring means 10, requesting means 20, and deciding means 30 may be a inquiring processor, requesting processor, and deciding processor, respectively.

The inquiring means 10 inquires, from a source mobile edge computing platform, a usage information (S10). The usage information indicates if a terminal uses a mobile edge computing application of the source mobile edge computing platform. The requesting means 20 requests, from a target base station, a support information (S20). The support information indicates if the mobile edge computing application is supported at the target base station.

S10 and S20 may be performed in an arbitrary sequence. They may be performed fully or partly in parallel.

The deciding means 30 decides on a handover of the terminal to the target base station based on the usage information and the support information (S30). That is, the deciding means decides, based on the usage information and the support information, whether or not the terminal is handed over to the target base station. Fig. 9 shows an apparatus according to an embodiment of the invention. The apparatus may be a MEC platform such as a source MEC platform or an element thereof. Fig. 10 shows a method according to an embodiment of the invention. The apparatus according to Fig. 9 may perform the method of Fig. 10 but is not limited to this method. The method of Fig. 10 may be performed by the apparatus of Fig. 9 but is not limited to being performed by this apparatus.

The apparatus comprises monitoring means 1 10, determining means 120, preparing means 130, and providing means 140. Each of the monitoring means 1 10, determining means 120, preparing means 130, and providing means 140 may be a monitoring processor, determining processor, preparing processor, and providing processor, respectively.

The monitoring means 1 10 monitors if a request to provide a usage information is received from a source base station (S1 10). The usage information indicates if a terminal uses a mobile edge computing application of a source mobile edge computing platform. The request may comprise an identification of the terminal. Typically, it may not comprise an identification of the mobile edge computing application.

The determining means 120 determines if the terminal uses the mobile edge computing application (S120). Based on a result of the determining by the determining means 120, the preparing means 130 prepares the usage information (S130).

Each of S120 and S130 may be performed only if the request is received or independent from such a request. The providing means 140 provides the usage information to the source base station in response to the received request (S140).

Fig. 1 1 shows an apparatus according to an embodiment of the invention. The apparatus may be a MEC platform such as a target MEC platform or an element thereof. Fig. 12 shows a method according to an embodiment of the invention. The apparatus according to Fig. 1 1 may perform the method of Fig. 12 but is not limited to this method. The method of Fig. 12 may be performed by the apparatus of Fig. 1 1 but is not limited to being performed by this apparatus. The apparatus comprises monitoring means 210, requesting means 220, preparing means 230, and providing means 240. Each of the monitoring means 210, determining means 220, preparing means 230, and providing means 240 may be a monitoring processor, determining processor, preparing processor, and providing processor, respectively.

The monitoring means 210 monitors if a request to provide a support information is received from a source base station (S210). The support information indicates if a mobile edge computing application is supported at a target base station.

The requesting means 220 requests to provide a capability information from a target mobile edge computing platform (S220). The capability information indicates if the target mobile edge computing platform supports the mobile edge computing application. Based on the capability information, the preparing means 230 prepares the usage information (S230).

Each of S120 and S130 may be performed only if the request for the support information is received or independent from such a request.

The providing means 140 provides the support information to the source base station in response to the received request for the support information (S140).

Fig. 13 shows an apparatus according to an embodiment of the invention. The apparatus may be a MEC platform such as a target MEC platform or an element thereof. Fig. 14 shows a method according to an embodiment of the invention. The apparatus according to Fig. 13 may perform the method of Fig. 14 but is not limited to this method. The method of Fig. 14 may be performed by the apparatus of Fig. 13 but is not limited to being performed by this apparatus.

The apparatus comprises monitoring means 310, determining means 320, preparing means 330, and providing means 340. Each of the monitoring means 310, determining means 320, preparing means 330, and providing means 340 may be a monitoring processor, determining processor, preparing processor, and providing processor, respectively.

The monitoring means 310 monitors if a request to provide a capability information is received from a target base station (S310). The capability information indicates if a target mobile edge computing platform supports a mobile edge computing application. The request may comprise an indication of the mobile edge computing application. The determining means 320 determines if the mobile edge computing application supports the mobile edge computing application (S320). Based on a result of the determining by the determining means 320, the preparing means 330 prepares the capability information (S330).

Each of S320 and S330 may be performed only if the request is received or independent from such a request.

The providing means 340 provides the capability information to the target base station in response to the received request (S340).

Fig. 15 shows an apparatus according to an embodiment of the invention. The apparatus may be a base station such as a source base station (NodeB, eNB) or an element thereof. Fig. 16 shows a method according to an embodiment of the invention. The apparatus according to Fig. 15 may perform the method of Fig. 16 but is not limited to this method. The method of Fig. 16 may be performed by the apparatus of Fig. 15 but is not limited to being performed by this apparatus.

The apparatus comprises providing means 410. The providing means 410 may be a providing processor.

The providing means 410 provides a list of one or more target base stations from a source base station to a mobile edge computing platform (S410). The list comprises those target base station(s), wherein a terminal connected to the source base station may handover to each of the target base station(s) with a probability larger than a predefined threshold.

Fig. 17 shows an apparatus according to an embodiment of the invention. The apparatus may be a MEC platform such as a source MEC platform or an element thereof. Fig. 18 shows a method according to an embodiment of the invention. The apparatus according to Fig. 17 may perform the method of Fig. 18 but is not limited to this method. The method of Fig. 18 may be performed by the apparatus of Fig. 17 but is not limited to being performed by this apparatus.

The apparatus comprises monitoring means 510, determining means 520, checking means 530, and providing means 540. Each of the monitoring means 510, determining means 520, checking means 530, and providing means 540 may be a monitoring processor, determining processor, checking processor, and providing processor, respectively.

The monitoring means 510 monitors if a list of one or more target base stations is received by a source mobile edge computing platform (S510).

If the list is received (S510 = "yes"), the determining means 520 determines one or more target mobile edge computing platforms (S520). The target mobile edge computing platforms are determined such that each of the target mobile edge computing platforms corresponds to respective at least one of the one or more target base stations comprised in the list.

If the list is received (S510 = "yes"), the checking means 530 checks if a terminal uses a mobile edge computing application of the source mobile edge computing platform (S530). S520 and S530 may be performed in an arbitrary sequence. They may be performed fully or partly in parallel.

If the terminal uses the mobile edge computing application (S530 = "yes"), the providing means 540 provides at least one of an application context and a user context of the application used by the terminal to each of the target mobile edge computing platforms determined by the determining means 520 (S540).

Fig. 19 shows an apparatus according to an embodiment of the invention. The apparatus comprises at least one processor 610, at least one memory 620 including computer program code, and the at least one processor 610, with the at least one memory 620 and the computer program code, being arranged to cause the apparatus to at least perform at least one of the methods according to Figs. 8, 10, 12, 14, 16, and 18.

One piece of information may be transmitted in one or plural messages from one entity to another entity. Each of these messages may comprise further (different) pieces of information.

Names of network elements, protocols, and methods are based on current 3GPP standards, in particular those for LTE. In other versions or other technologies, the names of these network elements and/or protocols and/or methods may be different, as long as they provide a corresponding functionality. For example, embodiments of the invention may be deployed in 2G/3G/4G/5G networks and further generations of 3GPP or a WLAN network.

Some embodiments were described related to a terminal. A terminal is a subscription device. It may be e.g. a UE, a UICC, a eUICC, a MTC device, a mobile station, or a SIM card, a USIM card, etc, or any other device related to a subscription in a mobile communication network.

Some embodiments of the invention were described related to an eNB. An eNB is an example of a base station. Other embodiments of the invention may use e.g. a BTS (e.g. in 2G networks) or a NodeB (e.g. in 3G networks) instead of the eNB.

If not otherwise stated or otherwise made clear from the context, the statement that two entities are different means that they perform different functions. It does not necessarily mean that they are based on different hardware. That is, each of the entities described in the present description may be based on a different hardware, or some or all of the entities may be based on the same hardware. It does not necessarily mean that they are based on different software. That is, each of the entities described in the present description may be based on different software, or some or all of the entities may be based on the same software. Each of the entities described in the present description may be embodied in the cloud.

According to the above description, it should thus be apparent that example embodiments of the present invention provide, for example, a computing platform such as a MEC platform, or a component thereof, an apparatus embodying the same, a method for controlling and/or operating the same, and computer program(s) controlling and/or operating the same as well as mediums carrying such computer program(s) and forming computer program product(s). According to the above description, it should thus be apparent that example embodiments of the present invention provide, for example, a base station such as a eNodeB or NodeB, or a component thereof, an apparatus embodying the same, a method for controlling and/or operating the same, and computer program(s) controlling and/or operating the same as well as mediums carrying such computer program(s) and forming computer program product(s).

Implementations of any of the above described blocks, apparatuses, systems, techniques or methods include, as non-limiting examples, implementations as hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. Some embodiments of the invention may be implemented in the cloud.

It is to be understood that what is described above is what is presently considered the preferred embodiments of the present invention. However, it should be noted that the description of the preferred embodiments is given by way of example only and that various modifications may be made without departing from the scope of the invention as defined by the appended claims.