WO2020015824A1

WO2020015824A1 - A method for a base station to indicate its overload status autonomously to the core network and its neighboring base stations to mitigate the overload condition

Info

Publication number: WO2020015824A1
Application number: PCT/EP2018/069426
Authority: WO
Inventors: Rajesh Babu NATARAJAN; Sumesh Parameswaran Nair
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2018-07-17
Filing date: 2018-07-17
Publication date: 2020-01-23

Abstract

A method and an apparatus are described, by which it is detected whether a first base station which comprises the apparatus is in an overload condition, and an overload start message indicating an overload condition of the first base station is sent to a peer network device via a dedicated interface defined for signaling between peer network devices, when it is detected that the base station is in an overload condition.

Description

A method for a base station to indicate its overload status autonomously to the core network and its neighboring base stations to mitigate the overload condition

Field of the Invention

The present invention relates to an apparatus, a method and a computer program product by a base station may indicate its overload status autonomously to the core network and its neighboring base stations to mitigate the overload condition.

Related background Art

The following meanings for the abbreviations used in this specification apply:

AMF Access and Mobility Function

ENB evolved Node B

MME Mobility Management Entity

N2 interface Interface between NG-RAN and AMF

NG-RAN Next generation radio access network

RRC Radio Resource Control

SGW Serving Gateway

X2 interface Interface between two ENB’s

Xn interface Interface between two NG-RANs

S1 interface Interface between an ENB and MME

UE User Equipment

UPF User Plane Function

Embodiments of the present invention, although not limited to this, relate to base stations such as ENB, and in particular to overload conditions thereof. In a mobile network, base stations are connected to the core network and provide the radio resources for the UE to connect them. In a dense area deployment, a base station might exhaust all its resources or reach over load condition due to various load factors.

When an ENB is overloaded, it cannot handle further new RRC connections or can experience degradation in the services that it offers to the existing UE’s, served by it. The overload condition can also result in handover failures if the overloaded ENB is chosen as the target ENB by its neighbor ENB. If the ENB is unable to normalize, the condition can further deteriorate and can lead to ENB restart resulting in service outage.

Summary of the Invention

Embodiments of the present invention address this situation and aim to provide measures for handling on overload condition of a base station.

According to a first aspect, an apparatus is provided which comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: detecting whether a first base station which comprises the apparatus is in an overload condition, and sending an overload start message indicating an overload condition of the first base station to a peer network device via a dedicated interface defined for signaling between peer network devices, when it is detected that the base station is in an overload condition.

According to a second aspect, a method is provided which comprises:

detecting whether a first base station which comprises the apparatus is in an overload condition, and

sending an overload start message indicating an overload condition of the first base station to a peer network device via a dedicated interface defined for signaling between peer network devices, when it is detected that the base station is in an overload condition.

The first and second aspects may be modified as follows:

For example, the peer network device may be a second base station and the dedicated interface may be a dedicated interface defined for signaling between base stations.

Alternatively, the peer network device may be a network control element and the dedicated interface may be a dedicated interface defined for signaling between a base station and a core network.

Moreover, it may be detected whether the first base station is returned from the overload condition to a non-overload condition, and an overload stop message indicating that the overload condition is terminated may be sent via the dedicated interface to the peer network device.

A resource status update message may be received from the peer network device via the dedicated interface, and load of the first base station may be handled based on the received resource status update message.

The resource status update message may be received via a dedicated interface defined for signaling between a base station and a core network from the network control element.

Information about measures to avoid further overloading of the first base station may be included into the overload start message.

According to a third aspect, an apparatus is provided which comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receiving an overload start message indicating an overload condition of a first base station via a dedicated interface defined for signaling between peer network devices, and performing control of signaling procedures concerning the first base station based on the received overload start message.

According to a fourth aspect, a method is provided which comprises:

receiving, in an apparatus, an overload start message indicating an overload condition of a first base station via a dedicated interface defined for signaling between peer network devices, and

performing control of signaling procedures concerning the first base station based on the received overload start message.

The third and fourth aspects may be modified as follows:

The overload start message may be received from the first base station.

The apparatus may be a second base station and the dedicated interface may be a dedicated interface defined for signaling between base stations. Alternatively, the apparatus may be or may be part of a network control element and the dedicated interface is a dedicated interface defined for signaling between a base station and a core network.

Moreover, when the apparatus is a network control element, the apparatus may inform a third base station about the overload condition of the first base station, for example when the third base station is not capable of communicating with the first base station via a dedicated interface defined for signaling between base stations.

In this case, the apparatus may forward the overload start message and/or an overload stop message received from the first base station to the third base station, and/or forward a resource status update message received from the third base station to the first base station.

Alternatively, the apparatus may be a third base station which is not capable of communicating with the first base station via a dedicated interface defined for signaling between base stations, and the third base station may receive the overload start message from a network control element.

Moreover, a resource status update message may be sent in response to receiving the overload start message to the peer network device via the dedicated interface.

The resource status update message may be sent via a dedicated interface defined for signaling between a base station and a core network to the network control element.

The overload start information may comprise information about measures to avoid further overloading.

An overload stop message indicating that the overload condition of the first base station is terminated may be received via the dedicated interface, and control of signaling procedures concerning the first base station may be performed based on the received overload stop message. That is, the normal operation may be resumed.

The dedicated interface defined for signaling between base stations may be an X2 interface or an Xn interface, and/or the dedicated interface defined for signaling between a base station and a core network may be an S1 interface or an N2 interface. According to a fifth aspect of the present invention a computer program product is provided which comprises code means for performing a method according to any one of the second, fourth, sixth and eighth aspects and/or their modifications when run on a processing means or module. The computer program product may be embodied on a computer-readable medium, and/or the computer program product may be directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.

According to a sixth aspect an apparatus is provided which comprises means for detecting whether a first base station which comprises the apparatus is in an overload condition, and means for sending an overload start message indicating an overload condition of the first base station to a peer network device via a dedicated interface defined for signaling between peer network devices, when it is detected that the base station is in an overload condition.

According to a seventh aspect, an apparatus is provided which comprises means for receiving an overload start message indicating an overload condition of a first base station via a dedicated interface defined for signaling between peer network devices, and means for performing control of signaling procedures concerning the first base station based on the received overload start message.

Brief Description of the Drawings

These and other objects, features, details and advantages will become more fully apparent from the following detailed description of embodiments of the present invention which is to be taken in conjunction with the appended drawings, in which:

Fig. 1 shows examples for ENBs and an MME according an embodiment,

Fig. 2A shows a flowchart of a procedure carried out by an overloaded ENB according to an embodiment,

Fig. 2B shows a flowchart of a procedure carried out by an MME or an ENB according to an embodiment, Fig. 3 shows a 4G network arrangement in which an ENB indicates an overload condition to peer network devices according to an embodiment,

Fig. 4 shows a network arrangement, in which the ENB indicates recovery from the overload condition to peer network devices according to an embodiment,

Fig. 5 shows a signaling flow in which an ENB indicates an overload condition to peer network devices according to an embodiment,

Fig. 6 shows a signaling flow in which the ENB indicates recovery from the overload condition to peer network devices according to an embodiment,

Fig. 7 shows a 5G network arrangement in which an NG-RAN indicates an overload condition to peer network devices according to an embodiment,

Fig. 8 shows a network arrangement, in which the NG-RAN indicates recovery from the overload condition to peer network devices according to an embodiment,

Fig. 9 shows a signaling flow in which an NG-RAN indicates an overload condition to peer network devices according to an embodiment, and

Fig. 10 shows a signaling flow in which the NG-RAN indicates recovery from the overload condition to peer network devices according to an embodiment.

Detailed Description of embodiments

In the following, description will be made to embodiments of the present invention. It is to be understood, however, that the description is given by way of example only, and that the described embodiments are by no means to be understood as limiting the present invention thereto.

Before describing embodiments in detail, the problem underlying the present application is described in some more detail.

As mentioned above, an overload condition of a base station such as an ENB may result to signaling failures and possibly service outage of the base station. As per the current 3GPP standard implementation, there is no method for an ENB to indicate its overload condition to its core network and its neighboring base stations by itself. The connecting nodes like MME and other ENB’s won’t be aware that the ENB is overloaded and will try to engage the ENB for several call processing procedures, causing it to load further.

Embodiments of the present invention aim to overcome this problem by allowing a base station to autonomously indicate an overload condition (overload status) to the core network and/or neighboring base stations. By doing so, the overload condition can be mitigated.

In the following, a general overview of some embodiments is described by referring to Figs. 1 , 2A and 2B.

In particular, Fig. 1 shows an ENB 1 as an example for a first apparatus according to the present embodiment. However, the invention is not limited to an ENB, but can be any kind of base station, which provides a radio connection to a user equipment. Moreover, the first apparatus may also be a part of the ENB only. Furthermore, Fig. 1 shows an MME 2 as an example for second apparatus. However, the invention is not limited to a MME, but can be any kind of network control device that provides a connection between base stations and a core network. Moreover, Fig. 1 shows an ENB 3 as an example for a third apparatus, which may have similar structure as the ENB 1. A connection between the ENB 1 and the MME 2 is provided via an S1 interface or any similar interface connecting a base station and the core network, and a connection between the ENB 1 and the ENB 3 is provided between an X2 interface or any similar interface connecting a base station with another base station. Although not shown, also the MME 2 and the ENB 3 may be connected via an S1 interface.

It is noted that the MME 2 and the ENB 3 are examples for peer network devices or peer nodes of the ENB 1. Fig. 2A illustrates a process carried out by the ENB 1 , and Fig. 2B illustrates a process carried out by the MME 2 and/or the ENB 3. In the following, it is assumed that the ENB 1 experiences an overload condition.

The ENB 1 comprises at least one processor 1 1 and at least one memory 12 including computer program code. The at least one processor 1 1 , with the at least one memory 12 and the computer program code, is configured to cause the apparatus to perform: detecting whether a first base station (e.g., the ENB 1 ) which comprises the apparatus is in an overload condition (as shown in ST1 1 in Fig. 2a), and sending an overload start message indicating an overload condition of the first base station to a peer network device (e.g., MME 2 or ENB 3) via a dedicated interface dedicated interface defined for signaling between peer network devices, when it is detected that the base station is in an overload condition (as shown in ST12 in Fig. 2a).

The MME 2 comprises at least one processor 21 and at least one memory 22 including computer program code. The at least one processor 21 , with the at least one memory 22 and the computer program code, is configured to cause the apparatus to perform: receiving an overload start message indicating an overload condition of a first base station (e.g., the ENB 1 ) via a dedicated interface defined for signaling between peer network devices (as shown in ST21 in Fig. 2b), and performing control of signaling procedures concerning the first base station based on the received overload start message (as shown in ST22 in Fig. 2b).

In this way, the ENB 1 , i.e., the overloaded base station, can easily autonomously indicate to peer network devices that it is in an overload condition, so that the peer network devices may correspondingly adapt signaling procedures with respect to the overloaded base station, so that the overload condition can be removed.

The peer network device described above may be a second base station (e.g., the ENB 3). In this case, the dedicated interface is an interface which is defined between two peer base stations, and may be an X2 interface. In this case, the procedures shown in Fig. 2b are carried out by the second base station (ENB 3).

Alternatively, peer network device described above may be a network control element (e.g., the MME 2). In this case, the dedicated interface is an interface that is defined between a base station and a network control element, and may be an S1 interface. In this case, the procedures shown in Fig. 2b are carried out by the network control element (MME).

It is noted that the ENBs 1 and 3 and the MME (or the corresponding apparatuses) may further comprise input/output (I/O) units or functions 13, 23, 33 connected to the processor 1 1 , 21 , 31 in order to provide connections to other elements.

In the following, the above embodiments are described in more detail.

In particular, according to some embodiments, an ENB overload condition is propagated to peer nodes (peer network devices) such as MME and neighboring ENBs. For this, several new messages are introduced, as listed in the following:

X2: overload start. This is sent by overloaded ENB (ENB 1 shown in Fig. 1 ) to indicate the overload condition to its neighbor ENB (ENB 3 shown in Fig. 1 ) through X2 interface.

S1 : overload start. This message is sent by the overloaded ENB (ENB 1 shown in Fig. 1 ) to indicate the Overload condition to MME (MME 2 shown in Fig. 1 ) through S1 interface.

S1 : neighbor ENB overload start. This is sent by the MME (MME 2 shown in Fig. 1 ), after receiving overload start from one of its ENBs to a neighbor ENB which does not have X2 interface with the overloaded ENB, to indicate overload condition.

X2: overload stop. This message is sent by the ENB to indicate the return to normal load to its neighbor ENB (ENB 3 shown in Fig. 1 ) through X2 interface.

S1 : overload stop. This message is sent by the ENB to indicate the return to normal load (non-overload condition) to the MME through S1 interface.

S1 : Neighbor ENB overload stop. This message is sent by the MME, after receiving overload stop from one of its ENBs to neighbor ENB which do not have X2 interface with ENB, to indicate return to normal load.

Overload action. That is, based on the overload start message, both the MME and neighboring ENBs decide to either include or exclude overloaded ENB for further signaling procedures. Once the overload stop message is received, both the MME and neighboring ENBs will resume normal operations.

Thus, according to embodiments of the present invention, a method is available for an ENB to indicate its overload status to the MME. Moreover, a method is provided for an ENB to indicate its overload status to neighboring ENBs via the X2 interface, and also to neighboring ENBs which are not connected to the ENB through the X2 interface.

Further detailed examples are described in the following by referring to Figs. 3 to 6.

As described above, according to some embodiments, a method for the ENB to inform the core network and neighboring ENBs about its overload condition and the actions the nodes need to take to mitigate its load condition is provided. These actions will be enforced until the condition of the ENB changes from overload to normal load depending on various load parameters at the ENB. Once the ENB returns to normal load condition, it updates the status to the core network and its neighboring ENBs, so that operations at the peers also could return to normal.

Fig. 3 shows an example comprising three ENBs, namely ENB1 , ENB2 and ENB3, two MMEs, namely MME1 and MME2 and an SGW. Moreover, a UE is illustrated as connected to ENB2. ENB1 and ENB2 are connected via the X2 interface, whereas ENB3 is not connected to ENB1 or ENB2 via the X2 interface. Moreover, ENB1 is connected to both MME1 and MME2 via the S1 interface (in more detail, S1 AP interface), ENB2 is connected to MME1 via the S1 AP interface, and ENB3 is connected to MME2 via the S1 AP interface. Furthermore, the SWG is connected to ENB1 to ENB3 via the S1 -U interface.

In the example shown in Fig. 3, it is assumed that ENB1 is in the overload condition. Since one ENB can be connected to multiple MMEs, for illustration purpose two MMEs - MME1 and MME2 are shown as connected to ENB1. Both ENB2 and ENB3 are neighbors to ENB1. The difference being that the X2 interface exists between ENB1 and ENB2, while it does not exist between ENB3 and ENB1. Neighbor ENB’s shown in the diagram are meant for illustration purpose to indicate different network deployment. As shown in Fig. 3, when ENB1 is in overload condition, it broadcasts the overload information (overload indication) to the MMEs and ENBs using the overload start message described above.

As illustrated, after having received the overload indication, the peer nodes (peer network devices) mark the ENB1 as overloaded. With the indication of the overload, peer nodes (MMEs and ENBs) take certain actions to mitigate the load condition, which are described in detail later.

Fig. 4 shows an example in which the ENB1 has moved out of overload condition and broadcasts this information to the MMEs and ENBs using the overload stop message described above.

That is, ENB1 informs MME1 , MME2, ENB2 and ENB3 about its condition returning to normal load for the peers to resume normal operations. That is, after having received the overload clear indication, the peer network devices (MME1 , MME2, ENB2, ENB3) unmark the ENB1 as overloaded. The above procedures are described in the following also by referring to signaling flow diagrams shown in Figs. 5 and 6. For ease of illustration, only one MME is assumed, wherein ENB1 , ENB2 and ENB3 are assumed to have a connection to the MME via the S1 interface (using S1 AP protocol). Moreover, as in the examples shown in Figs. 3 and 4, it is assumed that ENB3 does not have a connection via the X2 interface to ENB1 and ENB2.

Fig. 5 shows an example for an ENB overload indication to the core network (MME) and neighbor ENBs.

In A1 , ENB1 sends the X2: overload start message to ENB2 via the X2 interface. In A2, ENB1 sends the S1 : overload start message to MME via the X2 interface. In reaction to receiving the overload start message in A2, the MME sends the neighbor ENB overload start message to ENB3 in A3. In response to receiving the overload start message in A1 , ENB2 sends a X2: resource status update message to ENB1 in A4. Furthermore, ENB3 sends in response to receiving the neighbor ENB overload start message in A3 a resource status update message to the MME in A5. In A6, the MME sends a S1 : neighbor ENB resource status update message to ENB1 in A6.

In the resource status update message, the results of admitted measurements are reported. It is noted that in the present case this message is used in response to X2: Overload start (currently, this message is sent only in response to a successful Resource Status Reporting Initiation Procedure).

Thus, as shown in A7, at this point, all the peer nodes, i.e., ENB2, MME and ENB3 are informed about the overload condition of ENB1. Thus, these nodes will reduce signaling towards ENB1 based on certain overload action. By sharing its resource status update (from neighboring ENBs), it will help ENB1 to offload itself by handing over some of its serving UEs to neighboring ENBs. In other words, the peer base stations resource status message (in A4 and A6) sent to the overloaded base station (ENB1 ), will help the overloaded base station to offload some of its serving UEs to its neighboring base stations (ENB2 and ENB3).

In the following, some examples for the overload action are described. The overload action may be indicated by the overloaded ENB (e.g., ENB1 ) in the overload start message:

1 . Overload Action -“Allow only emergency/high priority sessions”

a. MME: Selects overloaded ENB to page only emergency/high priority sessions.

b. Neighbor ENB (ENB2 and ENB3): Selects overloaded ENB as target during handover of only emergency/high priority sessions.

2. Overload Action -“Reject All”

a. Overloaded ENB is not selected by MME/neighbor ENB for any signaling until Overload stop message is received indicating - return to normal operations.

Fig. 6 shows an example for ENB overload clear to the core network (MME) and the neighbor ENBs.

After the overload condition is terminated, ENB1 sends an X2: overload stop message via the X2 interface to ENB2 in B1. In B2, ENB2 sends an S1 overload stop message via the S1 interface to MME. In B3, the MME sends an S1 : Neighbor ENB overload stop message to ENB3.

Hence, as indicated in B4, at this points, all the peer nodes, ENB2, MME and ENB3, are informed about the overload clear status. Thus, all the nodes resume normal operations with ENB1 .

The embodiment described above with respect to Figs. 3 to 6 is applied in a 4G network. However, embodiments can also be applied to a 5G network. Such an embodiment is described in the following by referring to Figs. 7 to 10.

Figs. 7 to 10 correspond to Figs. 3 to 6, respectively, wherein the entities, functions and interfaces shown in Figs. 3 to 6 are replaced by the corresponding entities, functions and interfaces according to 5G.

That is, in general, the ENB in a 4G network corresponds to NG-RAN in a 5G network, MME corresponds to AMF, and the SGW corresponds to UPF in a 5G network. That is, in a 5G network, the base station is termed NG-RAN or gNB, and a network control device providing a connection between a base station and the core network is termed AMF. The interface between NG-RAN and AMF is termed as N2, and, hence, corresponds to the S1 interface in a 4G network. The interface between two NG RANs is termed as Xn and, hence, corresponds to the X2 interface in a 4G network.

Fig. 7 shows a similar example as Fig. 3, in which three NG-RANs, namely NG-RAN1 , NG- RAN2 and NG-RANs, two AMFs, namely AMF1 and AMF2 and an UPF are provided. NG- RAN 1 and NG-RAN2 are connected via the Xn interface, whereas NG-RAN3 is not connected to NG-RAN 1 or NG-RAN 2 via the Xn interface. NG-RAN 1 is connected to both AMF1 and AMF2 via the N2 interface (using NGAP protocol), NG-RAN2 is connected to AMF1 via the N2 interface, and NG-RAN3 is connected to AMF2 via the N2 interface. Furthermore, the UPF is connected to NG-RAN1 to NG-RAN3 via the N3 interface.

It is assumed that NG-RAN1 is in the overload condition. When NG-RAN1 is in overload condition, it broadcasts the overload information (overload indication) to the AMFs and NG- RANs using the overload start message described above.

As illustrated, after having received the overload indication, the peer nodes (peer network devices) mark the NG-RAN1 as overloaded. With the indication of the overload, peer nodes (AMFs and NG-RANs) take certain actions to mitigate the load condition, which are similar as those described above in connection with Figs. 3 to 6.

Fig. 8 shows an example in which NG-RAN1 has moved out of overload condition and broadcasts this information to the AMFs and NG-RANs using the overload stop message described above.

That is, NG-RAN1 informs AMF1 , AMF2, NG-RAN2 and NG-RAN3 about its condition returning to normal load for the peers to resume normal operations. That is, after having received the overload clear indication, the peer network devices (AMF1 , AMF2, NG-RAN2, NG-RAN3) unmark the NG-RAN1 as overloaded.

The above procedures are also illustrated in the signaling flow diagrams shown in Figs. 9 and 10. These fully correspond to the signaling flows shown in Figs. 5 and 6, with the exception that the messages are exchanged between NG-RAN1 , NG-RAN2, NG-RAN3 and AMF via the corresponding interfaces, i.e., Xn or N2 (using XnAP or NGAP protocol). That is, Fig. 9 illustrates a NG-RAN Overloaded Indication to core network (AMF) and neighbor NG-RANs, and Fig. 10 illustrates a NG-RAN Overloaded Clear to core network (AMF) and neighbor NG-RANs.

Thus, embodiments of the present invention provide a reliable way for a base station to autonomously indicate an overload condition to its peer nodes and to indicate recovery from the overload condition to its peer nodes.

Embodiments of the present invention are not limited to the examples as given before.

For example, according to some embodiments described above, the base stations are ENBs or NG-RANs. However, the embodiments are not limited to ENBs, and other kinds of base stations may be applied. Also the MME or AMF is only an example for a network control device, which provides a connection between base stations and a core network.

Names of network elements, protocols, and methods are based on current standards. 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.

In general, the example embodiments may be implemented by computer software stored in the memory (memory resources, memory circuitry) 12, 22, 32 and executable by the processor (processing resources, processing circuitry) 1 1 , 21 , 31 or by hardware, or by a combination of software and/or firmware and hardware.

As used in this application, the term "circuitry" refers to all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of "circuitry" applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device.

The terms "connected," "coupled," or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as non-limiting examples. The memory (memory resources, memory circuitry) 12, 22, 32 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, and non-transitory computer-readable media. The processor (processing resources, processing circuitry) 11 , 21 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi core processor architecture, as non-limiting examples. It is to be understood that the above description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

Claims

1 . An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: detecting whether a first base station which comprises the apparatus is in an overload condition, and

2. The apparatus according to claim 1 , wherein

the peer network device is a second base station and the dedicated interface is a dedicated interface defined for signaling between base stations, or

the peer network device is a network control element and the dedicated interface is a dedicated interface defined for signaling between a base station and a core network.

3. The apparatus according to claim 1 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

detecting whether the first base station is returned from the overload condition to a non-overload condition, and

sending an overload stop message indicating that the overload condition is terminated via the dedicated interface to the peer network device.

4. The apparatus according to any one of the claims 1 to 3, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

receiving a resource status update message from the peer network device via the dedicated interface, and

handling load of the first base station based on the received resource status update message.

5. The apparatus according to claim 4, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform: receiving the resource status update message via a dedicated interface defined for signaling between a base station and a core network from the network control element.

6. The apparatus according to any one of the claims 1 to 5, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

including information about measures to avoid further overloading of the first base station into the overload start message.

7. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receiving an overload start message indicating an overload condition of a first base station via a dedicated interface defined for signaling between peer network devices, and performing control of signaling procedures concerning the first base station based on the received overload start message.

8. The apparatus according to claim 7, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

receiving the overload start message from the first base station.

9. The apparatus according to claim 7 or 8, wherein

the apparatus is a second base station and the dedicated interface is a dedicated interface defined for signaling between base stations.

10. The apparatus according to claim 7 or 8, wherein

the apparatus is or is part of a network control element and the dedicated interface is a dedicated interface defined for signaling between a base station and a core network.

1 1 . The apparatus according to claim 10, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

informing a third base station about the overload condition of the first base station.

12. The apparatus according to claim 1 1 , wherein the third base station is not capable of communicating with the first base station via a dedicated interface defined for signaling between base stations.

13. The apparatus according to claim 1 1 or 12, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

forwarding the overload start message and/or an overload stop message received from the first base station to the third base station, and/or

forwarding a resource status update message received from the third base station to the first base station.

14. The apparatus according to claim 7, wherein

the apparatus is a third base station which is not capable of communicating with the first base station via a dedicated interface defined for signaling between base stations, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

receiving the overload start message from a network control element.

15. The apparatus according to any one of the claims 7 to 14, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

sending a resource status update message in response to receiving the overload start message to the peer network device via the dedicated interface.

16. The apparatus according to claim 15, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform:

sending the resource status update message via a dedicated interface defined for signaling between a base station and a core network to the network control element.

17. The apparatus according to any one of the claims 7 to 16, wherein the overload start information comprises information about measures to avoid further overloading.

18. The apparatus according to any one of the claim 7 to 17, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform: receiving an overload stop message indicating that the overload condition of the first base station is terminated via the dedicated interface, and

performing control of signaling procedures concerning the first base station based on the received overload stop message.

19. The apparatus according to any one of the claims 1 to 18, wherein

the dedicated interface defined for signaling between base stations is an X2 interface or an Xn interface, and/or

the dedicated interface defined for signaling between a base station and a core network is an S1 interface or an N2 interface.

20. A method comprising:

detecting, in a first base station, whether the first base station is in an overload condition, and

21 . The method to claim 20, wherein

22. A method comprising:

23. The method according to claim 22, wherein

the apparatus is a second base station and the dedicated interface is a dedicated interface defined for signaling between base stations, or

the apparatus is or is part of a network control element and the dedicated interface is a dedicated interface defined for signaling between a base station and a core network, or the apparatus is or is part of a network control element and the dedicated interface is a dedicated interface defined for signaling between a base station and a core network.

24. A computer program product comprising code means for performing a method according to any one of the claims 20 to 23 when run on a processing means or module.

25. The computer program product according to claim 24, wherein the computer program product is embodied on a computer-readable medium, and/or the computer program product is directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.