[0001] The present application relates generally to managing connections between wireless communication devices.

BACKGROUND

[0002] Cellular communication networks may comprise radio-access networks, RANs, configured to offer connectivity to user terminals via radio links, and core networks, CNs, configured to provide services related to running and managing the cellular communication network. Core network functions may comprise, for example, authenticating users seeking access to the network, providing interfaces to further networks, customer billing, subscriber database functions, network configuration and enforcing rules applied to data flows.

[0003] Core network functions may comprise user terminal mobility management, wherein a core network entity may participate in tracking mobile user terminals. When a user terminal moves to a new cell, it may initiate a tracking area update to maintain in the core network up-to-date reachability information, so the core network is enabled to route incoming communications, such as phone calls, to the correct cells.

[0004] RANs may be connected to CNs via interfaces configured to operate according to public specifications, wherein the public interface specifications enable a network operator to purchace a RAN from a first supplier and a CN from a second supplier to build his network, achieving interoperability between the network sections. User terminals may be provided by further suppliers, since radio interfaces between the user terminals and the RAN may also be specified in public industry specifications.

[0005] RANs may comprise base stations and, optionally, base station controller nodes.

Base station controller nodes may be known as base station controllers, BSC, as in global system for mobile communications, GSM, RANs, or radio network controllers, RNC, as in wideband code division multiple access, WCDMA, RANs. CNs for their part may comprise switches, database nodes, application functions, serving GPRS support nodes, wherein GPRS stands for general packet radio service, gateway GPRS support nodes and policy enforcement functions, for example, depending on the type of network. [0006] To connect a call between two user terminals, a cellular communication network may establish a data path that traverses, from the calling terminal, a base station comprised in a RAN, at least one CN entity, another base station comprised in a RAN and finally the called terminal. To connect a call to another network, the data path may traverse core networks of both of the respective networks, which may be connected to each other by gateway nodes comprised in the respective core networks.

SUMMARY

[0007] Various aspects of examples of the invention are set out in the claims.

[0008] According to a first aspect of the present invention, there is provided an apparatus, comprising a receiver configured to receive a handover request involving a first user equipment from a first base station, the handover request comprising an identity of a second base station, a transmitter configured to transmit a handover response to the first base station, wherein the apparatus is comprised in a third base station distinct from the first base station and the second base station.

[0009] According to a second aspect of the present invention, there is provided a method, comprising receiving in an apparatus a handover request involving a first user equipment from a first base station, the handover request comprising an identity of a second base station, and transmitting from the apparatus a handover response to the first base station, wherein the apparatus is comprised in a third base station distinct from the first base station and the second base station.

[0010] According to a third aspect of the present invention, there is provided an apparatus, comprising means for receiving a handover request involving a first user equipment from a first base station, the handover request comprising an identity of a second base station, and means for transmitting a handover response to the first base station, wherein the apparatus is comprised in a third base station distinct from the first base station and the second base station.

[0011] According to a fourth aspect of the present invention, there is provided a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code comprising code for receiving a handover request involving a first user equipment from a first base station, the handover request comprising an identity of a second base station, code for transmitting a handover response to the first base station, wherein the apparatus is comprised in a third base station distinct from the first base station and the second base station.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] For a more complete understanding of example embodiments of the present invention, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

[0013] FIGURE 1 illustrates an example system capable of supporting at least some embodiments of the present invention;

[0014] FIGURE 2 illustrates a block diagram of an apparatus in accordance with an example embodiment of the invention;

[0015] FIGURE 3 is a signaling diagram illustrating a method in accordance with at least some embodiments of the invention; and

[0016] FIGURE 4 is a flowgraph of a method according to an example embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0017] An example embodiment of the present invention and its potential advantages are understood by referring to FIGURES 1 through 4 of the drawings.

[0018] FIGURE 1 illustrates an example system capable of supporting at least some embodiments of the present invention. Illustrated are base stations 110, 120 and 130. The base stations may be configured to perform in accordance with an industry standard, such as for example a cellular standard. Examples of cellular standards suitable for supporting embodiments of the present invention include WCDMA and long term evolution, LTE, as specified by the 3 rd generation partnership project, 3GPP. FIG. 1 employs LTE terminology, which will be used herein with the understanding that the invention is not limited to LTE technology. In LTE, base stations comprised in a radio access network are known as eNBs. eNBs may be interconnected by interfaces known as X2 interfaces. FIG. 1 illustrates base stations 120 and 130 as connected to each other via an X2 interface, and similarly base stations 120 and 110, as well as 110 and 130, as likewise connected via X2 interfaces. The X2 interface may be a wire-line interface or at least in part wireless. [0019] Base stations 110, 120 and 130 may be comprised in base station sites supporting several cellular interfaces, such that a single base station site may host base stations acting in accordance with more than one standard. In some embodiments, a single physical apparatus is configured to act as a LTE base station, eNB, and a WCDMA base station.

[0020] At least one of base stations 110, 120 and 130, and in some embodiments each one of them, is connected to a core network. The core network comprises core network nodes tasked with controlling the cellular communication system as a whole. Core network functions, performed in core network nodes, which are not illustrated in FIG. 1, may comprise, for example, authentication, billing, subscriber database, routing and policy enforcement functions. Some core network nodes may act as gateway nodes, enabling the network to exchange information with further networks. In some embodiments, when a base station lacks a direct connection to a core network, it may communicate with a core network via an X2 interface and another base station that does have a direct connection to a core network.

[0021] Illustrated in FIG. 1 are also mobiles 140 and 150. The mobiles may comprise user equipments, mobile terminals, cellular telephones, tablet computers, laptop computers or other devices with cellular communication capability. A mobile seeking to place a call, such as for example a voice or video call, to another mobile may transmit a connection initiation signal to a base station over a wireless interface, wherein the wireless interface may perform in accordance with the cellular standard that also the base station performs in accordance with. Responsively, the base station may signal to the core network to request authorization for the call. If the core network authorizes the call, it may locate the called mobile using registers stored in the core network, and subsequently under the direction of the core network the base station may participate in routing the call. Participating in routing the call may comprise forwarding data from the calling mobile toward the called mobile, such as for example to the core network for further forwarding to the called mobile. Participating in routing the call may also comprise delivering data originating from the called mobile to the calling mobile, wherein the base station may receive the data from the core network and transmit it to the calling mobile over the air interface interconnecting the base station and the calling mobile.

[0022] The calling mobile may be configured to choose the base station to transmit the initiation signal to based on an attachment, wherein when the calling mobile is within a coverage area of the cellular system, it may consider itself attached to a certain cell, controlled by a certain base station, at any given time.

[0023] Alternatively to involving a core network, the radio access network comprising base stations and, optionally, base station controllers, may be configured to route a call without involving a core network. In such networks, the radio access network may request a core network to authorize a call before routing it, or the radio access network may decide

autonomously, without involving a core network, to authorize and route a call between two mobiles. FIG. 1 illustrates a call routed internally in a radio access network with dashed arrows marked with reference sign 101. Call 101 interconnects mobiles 140 and 150, and in doing so traverses base stations 120 and 130, and an X2 interface disposed between these two base stations.

[0024] Mobiles may move within the coverage area of the cellular system. The coverage area of the cellular system is subdivided into cells, each cell having a cell coverage area. If a mobile moves from a cell coverage area of a first cell to a cell coverage area of a second cell, it may undergo a handover procedure to change attachment from the first cell to the second cell. In general the first and second cells may be controlled by the same base station or by two distinct base stations. FIG. 1 illustrates a case where the first and second cells are controlled by different base stations, namely base station 120 and base station 110. Mobile 150 is illustrated as changing attachment from a cell controlled by base station 120 to a cell controlled by base station 110, from a schematic position 150 A to 150 B. In position B, the call previously routed along route 101 is delivered to mobile 150 via route 102, which traverses base stations 110 and 130, as well as an X2 interface disposed between these two base stations.

[0025] When handover from a cell controlled by base station 120 to a cell controlled by base station 110 occurs during a call routed via path 101, the call needs to be re-routed to a new path, such as path 102, in connection with the handover to prevent the call from being dropped as a consequence of the handover. To trigger the handover, mobile 150 may perform measurements of beacon signals, or reference signals, transmitted by base station 120 and base station 110. Mobile 150 may be configured to transmit measurement reports comprising result information of these measurements to base station 120 during attachment to base station 120. Responsive to determining, for example based on the measurement reports, that mobile 150 would be better served in a cell controlled by base station 110, base station 120 may transmit to base station 110 a handover request message. When base station 120 is in a path of a call routed internally in a radio-access network, without the route comprising a core network node, when the handover request is sent, the handover request may comprise an identity of a base station to which base station 120 forwards data along the routing path of the call. In the illustrated example, base station 120 routes data along path 101 to base station 130, wherefore the handover request may comprise an identity of base station 130, or an identity of a cell controlled by base station 130.

[0026] Responsive to receiving the handover request, base station 110 may perform an admission decision concerning mobile 150. The admission decision may depend on information comprised in the handover request, such as an identity of mobile 150, or an identity of a subscription active in mobile 150, or an identity of a subscriber using mobile 150. The admission decision may depend on the identity of the base station in the routing path of the active call, the identity being comprised in the handover request. In the example illustrated in FIG. 1 , base station 110 may accept mobile 150 responsive to determining that base station 110 has a direct interface to base station 130, an identity of which is comprised in the handover request. Since the direct interface exists, base station 110 can complete routing path 102 to maintain the active call internally in the radio access network. In some embodiments, base station 110 is configured to reject the handover, in other words to take a negative admission decision, responsive to a lack of a direct interface to the base station identified in the handover request.

[0027] In some embodiments, base station 110 is configured to accept the handover, but responsive to not having a direct interface to the base station identified in the handover request, convert the ongoing call into a call routed via a core network. Converting may be accomplished by signaling to the core network, the signaling comprising at least one of the identity of the base station included in the handover request and a call identity of the ongoing call routed internally in a radio access network. The core network is thus enabled to signal with base station 130 to change the routing of the call. In some embodiments base station 110 is configured to, responsive to not having a direct interface to the base station identified in the handover request, include in a handover response message a request to extend data path 101 to base station 110 from base station 120, in other words to forward data indended for mobile 150 from base station 120 to base station 110. In this case, the ongoing call can continue after the handover with bidirectional data forwarding between base stations 120 and 110 and path 101 would traverse, starting from mobile 150, base station 110, base station 120 and base station 130. A direct interface may comprise an interface comprised in a radio-access network, such as for example an X2 interface.

[0028] To signal a positive acceptance decision to admit mobile 150, base station 110 may be configured to respond to the handover request by transmitting a handover accept message, such as for example a handover request acknowledge, to base station 120. Base station 120 may be configured to signal a handover command to mobile 150 upon receipt of the handover accept message from base station 110. As part of the handover procedure, base station 110, which is a target base station of the handover, may signal to the base station identified in the handover request to cause the call routing path to be changed from path 101 to path 102, in other words for the path to be diverted to the target base station. Such a message may be called a path switch request. Thus the handover procedure may be seen to comprise, from the point of view of base station 110, receiving from base station 120 a handover request that identifies base station 130, transmitting a handover accept to base station 120, and transmitting a path switch request to the base station identified in the handover request, in this example base station 130. Base station 130 may respond to the path switch request with a path switch acknowledge message to indicate agreement to route the ongoing call internally in the radio access network to base station 110 instead of base station 120.

[0029] In some embodiments, the handover is an X2 -based handover wherein the handover request comprises an identity of a base station, different from the target base station, to which the source base station routes, before the handover, an ongoing call internally in the radio access network. In some of these embodiments, the handover request does not comprise an identity of a core network mobility management entity, MME. In some of these embodiments, the handover request does not comprise an identity of any core network entity.

[0030] In general there is provided an apparatus, such as for example base station 110 or a control device for inclusion in base station 110, to control the functioning of base station 110. The apparatus may comprise a receiver configured to receive, from a first base station, a handover request involving a first user equipment, the handover request comprising an identity of a second base station. The first base station may be a source base station and the second base station may be a base station to which the source base station routes, before the handover, an ongoing call internally in the radio access network, for example. The apparatus may further comprise a transmitter configured to transmit a handover response to the first base station. The handover response may comprise a handover accept, for example. The apparatus may be comprised in or as a third base station, distinct from the first base station and the second base station. Being distinct may comprise being sited on a different base station site, separated geographically from the first and second base stations. Being distinct may comprise that the third base station is not comprised in the first base station and that the third base station is not comprised in the second base station, and that both the first and the second base stations are external to the third base station. The receiver and transmitter may be enabled to exchange information with the first base station via an interface, such as for example an X2 interface, which may be a wire-line or at least in part wireless interface.

[0031] In some embodiments, the transmitter is caused to transmit the handover response responsive to the apparatus deciding to admit the first user equipment to a cell controlled by the third base station. The decision to admit may be an admittance decision, which may be based on an identity, for example an identity of a user equipment, which identity may be comprised in the handover request. The admittance decision may additionally or alternatively be based at least in part on a load situation of at least one cell controlled by base station 110.

[0032] In some embodiments, the transmitter is further caused to transmit a path switch message, such as a path switch request, to the second base station. The path switch message may be caused to be transmitted responsive to the first user equipment attaching successfully to a cell controlled by the third base station, for example. The path switch message may comprise an implicit or explicit request for the second base station to start routing an ongoing call, such as for example an ongoing call of the first user equipment, to the third base station instead of the first base station. The apparatus may be further configured to receive from the second base station a path switch response message, wherein the path switch response message may indicate acceptance from the second base station to begin routing the ongoing call to the third base station.

[0033] In some embodiments, the apparatus is further configured to route user data traffic from the first user equipment toward the second base station, and to route user data from a correspondent user equipment, received from the second base station, to the first user equipment. In other words the apparatus may be configured to perform routing of the ongoing call of the first user equipment by functioning as a routing node in a routing path of the ongoing call. The correspondent user equipment may be attached to a cell controlled by the second base station, or alternatively the second base station may just function as a routing node in a routing path of the ongoing call, to forward data intended for the correspondent node, received from the third base station, toward a further base station that controls a cell the correspondent user equipment is attached to. The routing path of the ongoing call may be internal to the radio access network between the second base station and the further base station.

[0034] FIGURE 3 is a signaling diagram illustrating a method in accordance with at least some embodiments of the invention. The vertical axes correspond to elements from FIG. 1 , namely, from left to right, mobile 150, mobile 140, base station 120, base station 130 and finally base station 110. In illustrated phase 310, mobiles 140 and 150 are engaged in an ongoing call, which is routed entirely within a radio access network, via base stations 120 and 130, corresponding to path 101 in FIG. 1. The interfaces of path 101 are illustrated in FIG. 3 with arrows furnished with reference symbols UP. Mobile 150 has an interface to base station 120, base station 120 has an interface with base station 130, and base station 130 has an interface with mobile 140.

[0035] In phase 320 mobile 150 may measure signal strengths of base station 120 and base station 110, whereby it may be discovered that a handover to a cell controlled by base station 110 may be beneficial, for example due to mobility of mobile 150 into a cell coverage area of such as cell. In phase 330, mobile 150 may transmit a measurement report of the measurement results to base station 120. Based at least in part on information contained in the measurement report, base station 120 may be configured to, in phase 340, transmit a handover request to base station 110. The handover request of phase 340 may comprise an identity of base station 130, or an identity of a cell controlled by base station 130. In some embodiments, the handover request of phase 340 doesn't comprise an identity of an MME. In some embodiments, the handover request of phase 340 doesn't comprise an identity of any core network function. The handover request may enable the radio access network to process the handover of the ongoing call autonomously of the core network.

[0036] In phase 350, base station 110, acting as target base station for the handover, may transmit a handover response to base station 120, which acts as a source base station for the handover. The handover response may comprise a handover accept message. A handover accept message may comprise a handover request acknowledge message. Responsive to the handover response message, the source base station, that is base station 120, may transmit a handover command to mobile 150, which is illustrated as phase 360. Being in receipt of the handover command, mobile 150 may complete handover to a cell controlled by base station 110, which is illustrated as phase 370. Completing handover may comprise synchronization and/or transmitting an initial data packet to the target base station 110. In phase 380, target base station 110 may transmit a path switch request message to base station 130, in other words to the base station identified in the handover request. Responsively, in phase 390, the base station identified in the handover request, in this example base station 130, may transmit a path switch request acknowledge message and cause routing of the ongoing call involving mobiles 140 and 150 to be diverted to base station 110, to cause routing to change to route 102 as illustrated in FIG. 1.

Finally, in phase 3100, mobiles 140 and 150 continue their session, or call, via base stations 110 and 130, and an interface interconnecting these two base stations. Although illustrated in the foregoing order, in some embodiments phase 380 may precede phase 370. Where base station 110 waits for phase 370 to complete before transmitting the message of phase 380, an advantage may be gained whereby should the handover fail, the path switch won't need to be reversed. Where on the other hand phase 380 precedes phase 370, an advantage may be gained whereby the procedure completes faster.

[0037] FIGURE 4 is a flowgraph of a method according to an example embodiment of the invention. The illustrated method may be performed in an apparatus such as base station 110, for example. In phase 410, the method comprises receiving in the apparatus a handover request involving a first user equipment from a first base station, the handover request comprising an identity of a second base station. In phase 420 the method comprises transmitting from the apparatus a handover response to the first base station, and element 430 specifies further that the apparatus is comprised in a third base station distinct from the first base station and the second base station.

[0038] FIGURE 2 illustrates a block diagram of an apparatus 10 such as, for example, base station 110, in accordance with an example embodiment of the invention. While several features of the apparatus are illustrated and will be hereinafter described for purposes of example, other types of electronic devices may employ various embodiments of the invention.

[0039] As shown, the apparatus 10 may include at least one antenna 12 in

communication with a transmitter 14 and a receiver 16. Alternatively transmit and receive antennas may be separate. The apparatus 10 may also include a processor 20 configured to provide signals to and receive signals from the transmitter and receiver, respectively, and to control the functioning of the apparatus. Processor 20 may be configured to control the functioning of the transmitter and receiver by effecting control signaling via electrical leads to the transmitter and receiver. Likewise processor 20 may be configured to control other elements of apparatus 10 by effecting control signaling via electrical leads connecting processor 20 to the other elements, such as for example a display or a memory. The processor 20 may, for example, be embodied as various means including circuitry, at least one processing core, one or more microprocessors with accompanying digital signal processor(s), one or more processor(s) without an accompanying digital signal processor, one or more coprocessors, one or more multi- core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits such as, for example, an application specific integrated circuit, ASIC, or field programmable gate array, FPGA, or some combination thereof. Accordingly, although illustrated in FIG. 2 as a single processor, in some embodiments the processor 20 comprises a plurality of processors or processing cores. Signals sent and received by the processor 20 may include signaling information in accordance with an air interface standard of an applicable cellular system, and/or any number of different wireline or wireless networking techniques, comprising but not limited to Wi-Fi, wireless local access network, WLAN, techniques such as Institute of Electrical and Electronics Engineers, IEEE, 802.11, 802.16, and/or the like. In addition, these signals may include speech data, user generated data, user requested data, and/or the like. In this regard, the apparatus may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, and/or the like. More particularly, the apparatus may be capable of operating in accordance with various first generation, 1G, second generation, 2G, 2.5G, third-generation, 3G, communication protocols, fourth-generation, 4G, communication protocols, Internet

Protocol Multimedia Subsystem, IMS, communication protocols, for example, session initiation protocol, SIP, and/or the like. For example, the apparatus may be capable of operating in accordance with 2G wireless communication protocols IS- 136, Time Division Multiple Access TDMA, Global System for Mobile communications, GSM, IS-95, Code Division Multiple Access, CDMA, and/or the like. Also, for example, the mobile terminal may be capable of operating in accordance with 2.5G wireless communication protocols General Packet Radio Service. GPRS, Enhanced Data GSM Environment, EDGE, and/or the like. Further, for example, the apparatus may be capable of operating in accordance with 3G wireless communication protocols such as Universal Mobile Telecommunications System, UMTS, Code Division Multiple Access 2000, CDMA2000, Wideband Code Division Multiple Access, WCDMA, Time Division-Synchronous Code Division Multiple Access, TD-SCDMA, and/or the like. The apparatus may be additionally capable of operating in accordance with 3.9G wireless communication protocols such as Long Term Evolution, LTE, or Evolved Universal Terrestrial Radio Access Network, E-UTRAN, and/or the like. Additionally, for example, the apparatus may be capable of operating in accordance with fourth-generation, 4G, wireless communication protocols such as LTE Advanced and/or the like as well as similar wireless communication protocols that may be developed in the future.

[0040] Some Narrow-band Advanced Mobile Phone System, NAMPS, as well as Total

Access Communication System, TACS, mobile terminal apparatuses may also benefit from embodiments of this invention, as should dual or higher mode phone apparatuses, for example, digital/analog or TDMA/CDMA/analog phones. Additionally, apparatus 10 may be capable of operating according to Wi-Fi or Worldwide Interoperability for Microwave Access, WiMAX, protocols.

[0041] It is understood that the processor 20 may comprise circuitry for implementing audio/video and logic functions of apparatus 10. For example, the processor 20 may comprise a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital- to-analog converter, and/or the like. Control and signal processing functions of the mobile terminal may be allocated between these devices according to their respective capabilities. The processor may additionally comprise an internal voice coder, VC, 20a, an internal data modem, DM, 20b, and/or the like. Further, the processor may comprise functionality to operate one or more software programs, which may be stored in memory. In general, processor 20 and stored software instructions may be configured to cause apparatus 10 to perform actions. For example, processor 20 may be capable of operating a connectivity program, such as a web browser. The connectivity program may allow the mobile terminal 10 to transmit and receive web content, such as location-based content, according to a protocol, such as wireless application protocol, WAP, hypertext transfer protocol, HTTP, and/or the like

[0042] Apparatus 10 may also comprise a user interface including, for example, an earphone or speaker 24, a ringer 22, a microphone 26, a display 28, a user input interface, and/or the like, which may be operationally coupled to the processor 20. In this regard, the processor 20 may comprise user interface circuitry configured to control at least some functions of one or more elements of the user interface, such as, for example, the speaker 24, the ringer 22, the microphone 26, the display 28, and/or the like. The processor 20 and/or user interface circuitry comprising the processor 20 may be configured to control one or more functions of one or more elements of the user interface through computer program instructions, for example, software and/or firmware, stored on a memory accessible to the processor 20, for example, volatile memory 40, non-volatile memory 42, and/or the like. Although not shown, the apparatus may comprise a battery for powering various circuits related to the mobile terminal, for example, a circuit to provide mechanical vibration as a detectable output. The user input interface may comprise devices allowing the apparatus to receive data, such as a keypad 30, a touch display, which is not shown, a joystick, which is not shown, and/or at least one other input device. In embodiments including a keypad, the keypad may comprise numeric 0-9 and related keys, and/or other keys for operating the apparatus.

[0043] As shown in FIG. 2, apparatus 10 may also include one or more means for obtaining data. For example, the apparatus may comprise a short-range radio frequency, RF, transceiver and/or interrogator 64 so data may be shared with and/or obtained from electronic devices in accordance with RF techniques. The apparatus may comprise other short-range transceivers, such as, for example, an infrared, IR, transceiver 66, a Bluetooth™' BT, transceiver 68 operating using Bluetooth™ brand wireless technology developed by the Bluetooth™ Special Interest Group, a wireless universal serial bus, USB, transceiver 70 and/or the like. The

Bluetooth™ transceiver 68 may be capable of operating according to low power or ultra-low power Bluetooth™ technology, for example, Wibree™, radio standards. In this regard, the apparatus 10 and, in particular, the short-range transceiver may be capable of transmitting data to and/or receiving data from electronic devices within a proximity of the apparatus, such as within 10 meters, for example. Although not shown, the apparatus may be capable of transmitting and/or receiving data from electronic devices according to various wireless networking techniques, including 6LoWpan, Wi-Fi, Wi-Fi low power, WLAN techniques such as IEEE 802.11 techniques, IEEE 802.15 techniques, IEEE 802.16 techniques, and/or the like.

[0044] The apparatus 10 may comprise memory, such as removable and/or fixed memory. The apparatus 10 may include volatile memory 40 and/or non-volatile memory 42. For example, volatile memory 40 may include Random Access Memory, RAM, including dynamic and/or static RAM, on-chip or off-chip cache memory, and/or the like. Non-volatile memory 42, which may be embedded and/or removable, may include, for example, read-only memory, flash memory, magnetic storage devices, for example, hard disks, floppy disk drives, magnetic tape, etc., optical disc drives and/or media, non-volatile random access memory, NVRAM, and/or the like. Like volatile memory 40, non-volatile memory 42 may include a cache area for temporary storage of data. At least part of the volatile and/or non-volatile memory may be embedded in processor 20. The memories may store one or more software programs, instructions, pieces of information, data, and/or the like which may be used by the apparatus for performing functions of the mobile terminal.

[0045] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is that calls routed internally in a radio access network can be handed over without involving a core network. Another technical effect of one or more of the example embodiments disclosed herein is that routing paths of calls routed internally in radio access networks can be updated.

[0046] Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware may reside on memory 40, the control apparatus 20 or electronic components, for example. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer- readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted in FIGURE 2. A computer- readable medium may comprise a computer-readable non-transitory storage medium that may be any media or means that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. The scope of the invention comprises computer programs configured to cause methods according to embodiments of the invention to be performed. [0047] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

[0048] Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[0049] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.