EP2805539A1

EP2805539A1 - Network listen mode control

Info

Publication number: EP2805539A1
Application number: EP12700963.7A
Authority: EP
Inventors: Klaus Ingemann Pedersen; Troels Emil Kolding
Original assignee: Nokia Solutions and Networks Oy
Current assignee: Nokia Solutions and Networks Oy
Priority date: 2012-01-16
Filing date: 2012-01-16
Publication date: 2014-11-26
Also published as: WO2013107494A1

Abstract

There are provided measures for network listen mode control. Such measures exemplarily comprise a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, a network listen mode measurement in accordance with the properties of the requested network listen mode measurement at the second base station, a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the network listen mode measurement, and network control and/or management on the basis of the result of the network listen mode measurement at the first base station. Such measures are exemplarily, but not exclusively, applicable in heterogeneous network deployments.

Description

Title

Network listen mode control

Field

The present invention relates to network listen mode control. More specifically, the present invention exemplarily relates to measures (including methods, apparatuses and computer program products) for network listen mode control, specifically but not exclusively in heterogeneous network deployments.

Background

The present specification basically relates to an effective control of a network listen mode (NLM) at a base station of a communication network. Such network listen mode (NLM) is generally applicable in any (cellular) communication system and/or network deployment, i.e. at any kind of base station in such (cellular) communication system and/or network deployment .

The network listen mode (NLM) refers to a mechanism in which a base station stops transmitting and utilizes an integrated UE receiver functionality to measure on downlink signals transmitted from other base stations. Conventionally, NLM mechanisms are known e.g. in the context of femto cells, which are controlled by a centralized network entity (such as an O&M system, e.g. a H(e)NB-GW entity), wherein NLM measurements are used locally at the femto cells for auto-configuration purposes and/or centrally at the centralized network entity for centralized network optimization purposes.

A timely availability of a NLM measurement result of the base station at other network elements is considered to have several promising applications in terms of network control and/or management. In this regard, inter-cell interference control, power control settings, inter-cell time synchronization, neighbor cell relations, handover and/or mobility settings, and energy management could be mentioned as non-limiting examples.

Despite such applications and benefits of having timely availability of a NLM measurement result of a base station at other network elements, there is also a cost or drawback of performing such NLM measurement at the base station. On the one hand, in order to be capable of perform NLM measurement, the base station needs to have NLM-capable UE receiver functionality. On the other hand, in order to actually perform NLM measurement, the base station needs to stop its ordinary transmission (i.e. its functionality as network access entity for UEs) when performing NLM measurements. Accordingly, the base station is not able to schedule any users during the time period where NLM measurement is performed.

While the former cost or drawback is inevitable in the context of a NLM-capable base station, the latter cost or drawback could be mitigated by way of an effective NLM control .

Therefore, there is a need to provide for an effective network listen mode control, which is suitable for mitigating problems arising when a base station resides in network listen mode (namely, due to the mutual exclusion of base station functionality and NLM functionality in time) .

Summary

Various exemplary embodiments of the present invention aim at addressing at least part of the above issues and/or problems and drawbacks.

Various aspects of exemplary embodiments of the present invention are set out in the appended claims.

According to an exemplary aspect of the present invention, there is provided a method comprising making a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, acquiring a network listen mode report from the second base station at the first base station, said network listen mode report comprising a result of the requested network listen mode measurement, and utilizing the acquired result of the requested network listen mode measurement for at least one of network control and management at the first base station .

According to an exemplary aspect of the present invention, there is provided a method comprising acquiring a network listen mode request from a first base station at a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, performing the requested network listen mode measurement in accordance with the acquired properties of the requested network listen mode measurement at the second base station, and making a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the performed network listen mode measurement.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising an interface configured to communicate with at least another apparatus, and a processor configured to cause the apparatus to perform: making a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, acquiring a network listen mode report from the second base station at the first base station, said network listen mode report comprising a result of the requested network listen mode measurement, and utilizing the acquired result of the requested network listen mode measurement for at least one of network control and management at the first base station. According to an exemplary aspect of the present invention, there is provided an apparatus comprising an interface configured to communicate with at least another apparatus, and a processor configured to cause the apparatus to perform: acquiring a network listen mode request from a first base station at a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, performing the requested network listen mode measurement in accordance with the acquired properties of the requested network listen mode measurement at the second base station, and making a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the performed network listen mode measurement.

According to an exemplary aspect of the present invention, there is provided a computer program product comprising computer-executable computer program code which, when the program is run on a computer (e.g. a computer of an apparatus according to any one of the aforementioned apparatus-related exemplary aspects of the present invention) , is configured to cause the computer to carry out the method according to any one of the aforementioned method-related exemplary aspects of the present invention.

Such computer program product may comprise or be embodied as a (tangible) computer-readable (storage) medium or the like on which the computer-executable computer program code is stored, and/or the program may be directly loadable into an internal memory of the computer or a processor thereof. Advantageous further developments or modifications of the aforementioned exemplary aspects of the present invention are set out in the following.

By way of exemplary embodiments of the present invention, there is provided network listen mode control. More specifically, by way of exemplary embodiments of the present invention, there are provided measures and mechanisms for network listen mode control (in/for any (cellular) communication system and/or network deployment) .

Thus, improvement is achieved by methods, apparatuses and computer program products enabling/realizing network listen mode control (in/for any (cellular) communication system and/or network deployment) .

Brief description of the drawings

In the following, the present invention will be described in greater detail by way of non-limiting examples with reference to the accompanying drawings, in which

Figure 1 shows a schematic diagram of a heterogeneous network deployment, for which exemplary embodiments of the present invention are applicable, Figure 2 shows a schematic diagram of logical network layers of a heterogeneous network deployment, for which exemplary embodiments of the present invention are applicable,

Figure 3 shows a schematic diagram of an exemplary procedure according to exemplary embodiments of the present invention,

Figure 4 shows a schematic diagram of another exemplary procedure according to exemplary embodiments of the present invention, and

Figure 5 shows a schematic diagram of exemplary apparatuses of according to exemplary embodiments of the present invention .

Detailed description of drawings and embodiments of the present invention

The present invention is described herein with reference to particular non-limiting examples and to what are presently considered to be conceivable embodiments of the present invention. A person skilled in the art will appreciate that the invention is by no means limited to these examples, and may be more broadly applied. It is to be noted that the following description of the present invention and its embodiments mainly refers to specifications being used as non-limiting examples for certain exemplary network configurations and deployments. Namely, the present invention and its embodiments are mainly described in relation to 3GPP specifications being used as non-limiting examples for certain exemplary network configurations and deployments. In particular, a LTE/LTE- Advanced communication system is used as a non-limiting example for the applicability of thus described exemplary embodiments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples, and does naturally not limit the invention in any way. Rather, any other network configuration or system deployment, etc. may also be utilized as long as compliant with the features described herein.

In particular, the present invention and its embodiments may be applicable in any (cellular) communication system and/or network deployment with a NLM-capable base station. In this regard, LTE/LTE-A, UMTS, WCDMA and HSPA could be mentioned as non-limiting examples.

Hereinafter, various embodiments and implementations of the present invention and its aspects or embodiments are described using several variants and/or alternatives. It is generally noted that, according to certain needs and constraints, all of the described variants and/or alternatives may be provided alone or in any conceivable combination (also including combinations of individual features of the various variants and/or alternatives) .

According to exemplary embodiments of the present invention, in general terms, there are provided measures and mechanisms for (enabling/realizing) network listen mode control (in/for any (cellular) communication system and/or network deployment) .

In the following, the present invention and its aspects or embodiments are exemplarily described for a non-limiting use case of a LTE/LTE-A-based heterogeneous network deployment .

Generally, heterogeneous network deployments, also referred to as multi-layer cellular network systems, comprise a combination of macro cells and micro cells (also referred to as pico cells or femto cells or the like) . Thereby, the macro cells (having high transmission power) typically provide for a large geographical coverage, while the micro cells (having low transmission power) typically provide for additional capacity of low geographical coverage in areas with a high user deployment. In the context of LTE or LTE- Advanced, the macro cells are typically deployed by base stations denoted as eNBs, while micro cells are typically deployed by remote radio heads (RRH) , herein denoted as pico/micro eNB, such as mobile or fixed relay nodes, home base stations, or the like. Examples of heterogeneous network deployments exemplarily include relay-enhanced access networks, and the like. Figure 1 shows a schematic diagram of a heterogeneous network deployment, for which exemplary embodiments of the present invention are applicable. In Figure 1, macro cells are illustrated by hexagonal blocks, while micro cells are illustrated by rectangular blocks (wherein it is noted that the shape of thus illustrating forms does not limit applicability but is just illustrative; e.g. the rectangular blocks of the micro cells encompasses both indoor and outdoor scenarios) . In the dashed circle, an enlarged view of a micro cell including a micro cell base station and a user equipment (UE) is illustrated.

Such heterogeneous network deployment may be considered to be composed at least of two (logical) network layers, i.e. an overlay (macro cell) network layer and an underlay (micro cell) network layer. The two network layers of a heterogeneous network deployment, i.e. the base stations and/or cells of the two network layers, may be implemented by the same or different radio access technologies. For example, a heterogeneous network deployment, for which exemplary embodiments of the present invention are applicable, may be composed of a LTE-based overlay (macro cell) network layer and a LTE-based underlay (micro cell) network layer.

Figure 2 shows a schematic diagram of logical network layers of a heterogeneous network deployment, for which exemplary embodiments of the present invention are applicable . In Figure 2, an exemplary scenario of two macro base stations located in the overlay (macro cell) network layer and two pico/micro base stations in the underlay (micro cell) network layer is assumed, which are mutually connected by way of X2 interfaces. Generally, exemplary embodiments of the present invention are applicable to such heterogeneous network deployment irrespective of the number of base stations in each network layer and the type and number/relation of their mutual connections (e.g. the type of interface) .

Hereinafter, procedures according to exemplary embodiments of the present invention are exemplified between a first base station BS#1 and a second base station BS#2.

According to exemplary embodiments of the present invention, referring to Figure 2, the first base station BS#1 may for example be any one of the two macro base stations located in the overlay (macro cell) network layer, and the second base station BS#2 may for example be any one of the two pico/micro base stations in the underlay (micro cell) network layer. Further, the first and second base stations BS#1 and BS#2 may also be base stations of the same overlay/underlay network layer, respectively.

According to exemplary embodiments of the present invention, when assuming a LTE/LTE-A communication system, any one of the first and second base stations may be an eNB, e.g. a LTE/LTE-A macro eNB or a LTE/LTE-A pico/micro eNB or any other kind of LTE/LTE-A base station. Otherwise, when assuming another communication system, any one of the first and second base stations may be any kind of base station in such system, e.g. any kind of UMTS base station, any kind of WCDMA base station, any kind of HSPA base station, or the like.

According to exemplary embodiments of the present invention, the first and second base stations BS#1 and BS#2 (i.e. the base stations in the same or different network layers) may be connected by way of any kind of logical (point-to-point) interface. As an example for a standardized interface, a X2 interface may be used, which is a logical interface for the interconnection of two E- UTRAN NodeB (eNB) components within the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) architecture. Also, any proprietary interface solution may also be used, which may for example be implemented by way of direct connectivity between the respective base stations or shared baseband techniques.

Figure 3 shows a schematic diagram of an exemplary procedure according to exemplary embodiments of the present invention .

As shown in Figure 3, a procedure according to exemplary embodiments of the present invention comprises the following operations/ functions . The first base station BS#1 makes a network listen mode (NLM) request to the second base station BS#2, wherein the NLM request comprises (at least) properties of a requested NLM measurement. This may be accomplished e.g. by transmitting a corresponding NLM request (message) over the e.g. X2 interface. Then, the second base station BS#2 acquires the NLM request from the first base station BS#1, e.g. by receiving the corresponding NLM request (message) over the X2 interface, and performs the requested NLM measurement in accordance with the properties of the requested NLM measurement, which are included in the NLM request from the first base station BS#1. After completion of the NLM measurement, the second base station BS#2 makes a NLM report to the first base station BS#1, wherein the NLM report comprises (at least) a result of the performed NLM measurement. This may be accomplished e.g. by transmitting a corresponding NLM report (message) over the e.g. X2 interface. Then, the first base station BS#1 acquires the NLM report from the second base station BS#2, e.g. by receiving the corresponding NLM report (message) over the X2 interface, and utilizes (or applies) the result of the requested NLM measurement, which is included in the NLM report from the second base station BS#2, for at least one of network control and management at the first base station.

According to exemplary embodiments of the present invention, the NLM request may also comprise properties and/or instructions for reporting the NLM measurement result from the second base station BS#1 back to the first base station BS#1. If so, the second base station BS#2 makes the NLM report in accordance with these properties and/or instructions of the NLM measurement reporting. Such properties and/or instructions may for example relate to a timing of the reporting, e.g. relative to the NLM measurement, certain triggers for the reporting, e.g. relating to a status at the second base station BS#2 and/or the interface/connection between the two base stations, a channel for the reporting, e.g. relating to the interface/connection to be used, a destination for the reporting e.g. relating to certain network elements in addition to the first base station BS#1, or the like.

According to exemplary embodiments of the present invention, the properties of the requested NLM measurement may comprise one or more of a time or time period for the network listen mode measurement, at least one condition for the network listen mode measurement, and at least one type of the network listen mode measurement.

In terms of properties relating to measurement time, the first base station BS#1 may specify an exact time or a time period (or interval) when the second base station BS#2 shall perform the requested NLM measurement.

In terms of properties relating to measurement type, the first base station BS#1 may specify the type of one or more NLM measurements, which the second base station BS#2 shall perform. The request may comprise a plurality (e.g. a list/set) of (types of) requested NLM measurements. The thus requested NLM measurements may be of any type, in particular of any type which may be useful in terms network control and/or management, possibly depending e.g. on the underlying (cellular) communication system and/or network deployment and/or operation mode.

For example, the requested NLM measurement may be an intra- carrier pathloss measurement from one or more of neighboring base stations being measurable by the second base station BS#2, i.e. base stations operating on the same carrier or frequency as the second base station BS#2. Further, the requested NLM measurement may for example be an inter-carrier pathloss measurement from one or more of neighboring base stations being measurable by the second base station BS#2, i.e. base stations operating on a carrier or frequency different from that of the second base station BS#2. The aforementioned pathloss measurements may for example be accomplished by way of measurements of RSRP and/or RSRQ from the one or more of neighboring base stations. Still further, the requested NLM measurement may for example be a timing measurement for one or more of neighboring base stations.

In the aforementioned measurement types, the referenced one or more of neighboring base stations may be all or a selected part of surrounding base stations (on the same or a different network layer) , respectively. Specifically, the first base station BS#1 may select those neighboring base stations for the respective measurement type or types, which are (particularly) useful in this regard. In the case of the aforementioned pathloss measurements, the relevant base station/s may be selected to be limited to cells with a specific PCI or other identifier. When selection is based on the PCI or another identifier, neighboring base stations within a specific range, e.g. base stations of specific types, could be selected for pathloss measurement purposes. In the case of the aforementioned timing measurement, the relevant base station/s may be selected to be limited to that/those which e.g. are useful for establishing an inter- BS time synchronization.

In terms of properties relating to measurement condition, the first base station BS#1 may specify the condition/s (or event/s) of one or more NLM measurements, under which the second base station BS#2 shall perform the NLM measurement. Such condition/s (or event/s) may for example comprise a load condition at the second base station BS#2, and/or a temporal condition of at least one of minimum and maximum periodicity of the requested NLM measurement.

For example, in terms of a load condition, the first base station BS#1 may specify that the second base station BS#2 shall perform the requested NLM measurement (followed by signaling of results of those measurements back to the first base station BS#1), when its load is below a predetermined load threshold, e.g. when it is not serving any connected mode UEs or it is serving only a limited number of connected mode UEs. Such load threshold may be implemented at the requesting base station, where information load information of the requested base station may be available via interface signaling (e.g. standard X2 signaling) . When an excessive load of the requested base station is identified at the requesting base station (i.e. a load higher than the load threshold) , a time window for the requested measurement may be defined, thereby providing some freedom to the requested base station to allow to empty a buffer, HARQ cycles or the like. Also, such load threshold may be implemented at the requested base station in that the requested base station is instructed to perform its requested measurement as soon as its load drops below the predetermined load threshold (which could be transmitted as part of the request) .

For example, in terms of a temporal condition, the first base station BS#1 may specify that the second base station BS#2 shall perform the requested NLM measurement (followed by signaling of results of those measurements back to the first base station BS#1) at most every X seconds and/or at least every Y seconds (wherein X and Y are freely selectable configuration parameters) .

Also, the aforementioned load and temporal conditions may be combined such that the second base station BS#2 shall perform the requested NLM measurement (followed by signaling of results of those measurements back to the first base station BS#1) in an event-triggered manner, yet with the periodicity-related limitations.

According to exemplary embodiments of the present invention, in order to ensure performing the requested NLM measurement in accordance with the defined properties thereof, the second base station BS#2 may monitor (satisfaction of) the individual properties. The requested NLM measurement may then only be performed when a respective property or respective properties are fulfilled. For example, any defined properties relating to measurement time may be monitored by time surveillance, e.g. by way of a timer, clock or the like. For example, any properties relating to measurement condition may be monitored by corresponding surveillance, e.g. by way of load monitoring, a timer/clock/etc. or the like. Such monitoring may be accomplished prior to or within the NLM measurement operation/ function illustrated in Figure 3.

According to exemplary embodiments of the present invention, utilizing the acquired result of the requested NLM measurement for a NLM-based network control/management at the first base station BS#1 may comprise any conceivable process, measure, procedure or the like, which is effective for improving network operation. For example, such NLM- based network control/management may comprise improving/optimizing one or more of inter-cell interference control, power control settings, inter-cell time synchronization, neighbor cell relations, and handover and/or mobility settings. Such NLM-based network control/management may be accomplished locally at the first base station BS#1 as such, at any other base station to which the first base station BS#1 provides the one or more NLM measurement results locally available, or in cooperation between the first base station BS#1 and any other base station.

In terms of inter-cell interference control, the NLM measurement result of a pathloss towards another base station (e.g. pathloss from a micro base station to the strongest macro base station/s) may be used to improve/ optimize interference management operation (e.g. optimization of (enhanced) inter-cell interference coordination e-/ICIC) . This may be specifically effective in co-channel scenarios (e.g. when micro and macro base station operate in a co-channel manner), and the like.

In terms of power control settings, the NLM measurement result of a pathloss towards another base station (e.g. pathloss from a micro base station to the strongest macro base station/s) may be used improve/ optimize setting of uplink power control parameters, deciding on the best settings for connected UEs (e.g. UE connected to macro and/or micro base station), and the like.

In terms of inter-cell time synchronization, the NLM measurement result of a timing (e.g. a macro base station timing) may be used to establish an improved/optimized time-synchronization between different base stations (e.g. between macro and micro base stations) .

In terms of neighbor cell relations and handover and/or mobility settings, the NLM measurement result of a pathloss towards another base station (e.g. pathloss from a micro base station to the strongest neighboring macro base station/s) may be used to build improved/optimized neighbor cell relations and for various handover performance improvements/ optimizations (e.g. relating to mobility parameters and triggers) . Figure 4 shows a schematic diagram of another exemplary procedure according to exemplary embodiments of the present invention .

As shown in Figure 4, a procedure according to exemplary embodiments of the present invention comprises the operations/ functions of the procedure according to Figure 3. In addition thereto, the procedure according to Figure 4 comprises at least one of the following operations/ functions (both of which are illustrated for the sake of simplicity in Figure 4) .

On the one hand, the first base station BS#1 may perform a NLM request control. In such NLM request control, the first base station BS#1 may control the NLM request in terms of at least one of frequency, timing and contents thereof. Such control may for example be based on one or more of a timing control at the first base station BS#1, a status control at the first base station BS#1, NLM measurements from entities other than the second base station BS#2, and any report or message relating to the second base station BS#2.

For example, the timing and/or frequency of NLM requests may be controlled/optimized based on timing, NLM measurements received from other sites, as well as by way of re-use of existing reports as triggers (e.g. standardized X2-carried reports) . As one example, the existing X2 Load Measure can be used as a dynamic trigger such that an eNB as the second base station BS#2 is only requested to perform NLM measurement when it has (very) low load (i.e. is not serving any or only few users) . Generally, any other measures, reports, messages or the like may also be used (additionally or alternatively) in this regard, particularly those being (directly or indirectly) indicative of an appropriateness/suitability of or available capacity/resources/etc. for performing NLM measurements at the second base station BS#2.

On the other hand, additionally or alternatively (and independent of the above-outlined NLM request control operation/ function, the second base station BS#2 may not only perform NLM measurement on its own, but may (additionally or alternatively) apply/utilize a result of a NLM measurement at another entity. Namely, when being requested accordingly (i.e. when the requested NLM measurement comprises at least one of a pathloss and a timing measurement at an entity other than the second base station BS#2), the second base station BS#2 may instruct another entity to perform such requested NLM measurement and/or to report a result of such requested NLM measurement back to the second base station BS#2.

Such requested NLM measurement may be (similar to) any one of the aforementioned measurement types, only that such requested NLM measurement is to be performed at another entity or in cooperation between the second base station BS#2 and another entity instead of at the second base station BS#2 as such. By way of such NLM measurements, the local NLM measurements at the second base station BS#2 may for example be supplemented in order to improve accuracy, reliability, etc. thereof. For example, such non-local NLM measurement may comprise a pathloss measurement (e.g. on the basis of RSRP and/or RSRQ) conducted by a UE connected the second base station BS#2 at a certain time or time period as specified in the NLM request, if any.

In view of the above, exemplary embodiments of the present invention provide for an effective network listen mode control, which may be specifically but not exclusively applied in heterogeneous network deployments.

By way of the effective network listen mode control according to exemplary embodiments of the present invention, as outlined above, aforementioned problems arising when a base station resides in network listen mode (namely, due to the mutual exclusion of base station functionality and NLM functionality in time) may be at least mitigated.

Specifically, the effective network listen mode control according to exemplary embodiments of the present invention involves a mechanisms in which NLM-related operations/ functions are accomplished (i.e. NLM measurement and NLM measurement result are requested/reported) between base stations, e.g. between base stations of the same or different network layers of a heterogeneous network deployment (without involving a centralized entity) , and in which a NLM measurement result is utilized/applied for network control/management at the requesting base stations (e.g. at a macro base station requesting NLM measurement from a micro base station in heterogeneous network deployment) .

An inter-base station mechanism in terms of NLM control according to exemplary embodiments of the present invention may involve control for when a requested base station shall perform a NLM measurement, and/or which NLM measurement/s requested base station shall perform, and/or how a NLM measurement result is made available for other base station nodes for their own benefit and/or for the mutual benefit of overall network performance optimization.

Specifically, aforementioned problems may thus be mitigated or solved by way of the following properties of the inter- base station NLM mechanism. By way of the request transmission as such, it may be ensured that measurements are only carried out by selected (i.e. requested) base stations when needed by the requesting base station. Further, by way of a measurement configuration in the request - it may be ensured that only relevant/useful measurements are carried out and/or (relevant/useful) measurements are only carried at a relevant/useful/appropriate time. Still further, by way of specific triggering conditions, it may be ensured that measurements are only performed when a selected (i.e. requested) base station, after receiving the request, can afford to carry out the requested measurements (without potentially compromising its ordinary transmission, i.e. its functionality as network access entity for UEs), wherein such triggering conditions may relate to load conditions at the selected (i.e. requested) base station and/or temporal conditions, as outlined above.

Stated in more general terms, NLM measuring overhead could be reduced by the inter-base station NLM mechanism according to exemplary embodiments of the present invention .

An inter-base station mechanism in terms of NLM control according to exemplary embodiments of the present invention may be advantageously accomplished over a standardized interface such as the X2 interface. In this regard, existing standards of such interface may be modified accordingly to allow for the above-outlined operations/ functions . For example, the X2 application protocol may be modified so as to capture the inter-base station mechanism in terms of NLM control according to exemplary embodiments of the present invention, as outlined above. Having a standardized inter-base station mechanism in terms of NLM control according to exemplary embodiments of the present invention may be considered to be beneficial for multi-vendor scenarios where e.g. macro and pico/micro base stations could be provided from different vendors.

Overall, an inter-base station mechanism in terms of NLM control according to exemplary embodiments of the present invention facilitates a more effective implementation of HetNet deployments or the like, where e.g. an underlay of LTE pico/micro cells are more tightly coupled to an overlay of LTE macro cells. This allows for a more efficient implementation of LTE/ LTE-A features as well as to reduce overall costs for semi-static/dynamic O&M/SON mechanisms for tuning network performance according to the current user distribution and load.

The above-described procedures and functions may be implemented by respective functional elements, processors, or the like, as described below. While in the foregoing exemplary embodiments of the present invention are described mainly with reference to methods, procedures and functions, corresponding exemplary embodiments of the present invention also cover respective apparatuses, network nodes and systems, including both software and/or hardware thereof.

Respective exemplary embodiments of the present invention are described below referring to Figure 5, while for the sake of brevity reference is made to the detailed description of respective corresponding schemes, methods and functionality, principles and operations according to Figures 1 to 4.

In Figure 5 below, the solid line blocks are basically configured to perform respective operations as described above. The entirety of solid line blocks are basically configured to perform the methods and operations as described above, respectively. With respect to Figure 5, it is to be noted that the individual blocks are meant to illustrate respective functional blocks implementing a respective function, process or procedure, respectively. Such functional blocks are implementation-independent, i.e. may be implemented by means of any kind of hardware or software, respectively. The arrows and lines interconnecting individual blocks are meant to illustrate an operational coupling there-between, which may be a physical and/or logical coupling, which on the one hand is implementation-independent (e.g. wired or wireless) and on the other hand may also comprise an arbitrary number of intermediary functional entities not shown. The direction of arrow is meant to illustrate the direction in which certain operations are performed and/or the direction in which certain data is transferred.

Further, in Figure 5, only those functional blocks are illustrated, which relate to any one of the above-described methods, procedures and functions. A skilled person will acknowledge the presence of any other conventional functional blocks required for an operation of respective structural arrangements, such as e.g. a power supply, a central processing unit, respective memories or the like. Among others, memories are provided for storing programs or program instructions for controlling the individual functional entities to operate as described herein.

In view of the above, the thus described apparatuses 10 and 20 are suitable for use in practicing the exemplary embodiments of the present invention, as described herein. The thus described apparatus 10 may represent a (part of a) network element such as a base station (e.g. a macro base station) , and may be configured to perform a procedure and/or exhibit a functionality as evident from the BS#1 side of any one of Figures 3 and 4. The thus described apparatus 20 may represent a (part of a) base station (e.g. a pico/micro base station) , and may be configured to perform a procedure and/or exhibit a functionality as evident from the BS#2 side of any one of Figures 3 and 4.

As indicated in Figure 5, according to exemplary embodiments of the present invention, each of the apparatuses comprises a processor 11/21, a memory 12/22 and an interface 13/23, which are connected by a bus 14/24 or the like, and the apparatuses may be connected via link A, respectively .

The processor 11/21 and/or the interface 13/23 may also include a modem or the like to facilitate communication over a (hardwire or wireless) link, respectively. The interface 13/23 may include a suitable transceiver coupled to one or more antennas or communication means for (hardwire or wireless) communications with the linked or connected device (s), respectively. The interface 13/23 is generally configured to communicate with at least one other apparatus, i.e. the interface thereof.

The memory 12/22 may store respective programs assumed to include program instructions or computer program code that, when executed by the respective processor, enables the respective electronic device or apparatus to operate in accordance with the exemplary embodiments of the present invention .

In general terms, the respective devices/apparatuses (and/or parts thereof) may represent means for performing respective operations and/or exhibiting respective functionalities, and/or the respective devices (and/or parts thereof) may have functions for performing respective operations and/or exhibiting respective functionalities.

When in the subsequent description it is stated that the processor (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that a (i.e. at least one) processor or corresponding circuitry, potentially in cooperation with computer program code stored in the memory of the respective apparatus, is configured to cause the apparatus to perform at least the thus mentioned function. Also, such function is to be construed to be equivalently implementable by specifically configured circuitry or means for performing the respective function (i.e. the expression "processor configured to [cause the apparatus to] perform xxx-ing" is construed to be equivalent to an expression such as "means for xxx-ing") .

In its most basic form, according to exemplary embodiments of the present invention, the apparatus 10 or its processor 11 is configured to perform making a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, acquiring a network listen mode report from the second base station at the first base station, said network listen mode report comprising a result of the requested network listen mode measurement, and utilizing the acquired result of the requested network listen mode measurement for at least one of network control and management at the first base station .

In its most basic form, according to exemplary embodiments of the present invention, the apparatus 20 or its processor 21 is configured to perform acquiring a network listen mode request from a first base station at a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, performing the requested network listen mode measurement in accordance with the acquired properties of the requested network listen mode measurement at the second base station, and making a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the performed network listen mode measurement.

According to exemplary embodiments of the present invention, the properties of the requested network listen mode measurement may comprise one or more of a time or time period for the network listen mode measurement, at least one condition for the network listen mode measurement, and at least one type of the network listen mode measurement. For further details regarding the operability/ functionality of the individual apparatuses, reference is made to the abode description in connection with any one of Figures 3 and 4, respectively.

According to exemplarily embodiments of the present invention, the processor 11/21, the memory 12/22 and the interface 13/23 may be implemented as individual modules, chips, chipsets, circuitries or the like, or one or more of them can be implemented as a common module, chip, chipset, circuitry or the like, respectively.

According to exemplarily embodiments of the present invention, a system may comprise any conceivable combination of the thus depicted devices/apparatuses and other network elements, which are configured to cooperate as described above.

In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts.

The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device. Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention. Such software may be software code independent and can be specified using any known or future developed programming language, such as e.g. Java, C++, C, and Assembler, as long as the functionality defined by the method steps is preserved. Such hardware may be hardware type independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor) , CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor- Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components. A device/apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device/apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor. A device may be regarded as a device/apparatus or as an assembly of more than one device/apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

Apparatuses and/or means or parts thereof can be implemented as individual devices, but this does not exclude that they may be implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof.

The present invention also covers any conceivable combination of method steps and operations described above, and any conceivable combination of nodes, apparatuses, modules or elements described above, as long as the above- described concepts of methodology and structural arrangement are applicable.

In view of the above, there are provided measures for network listen mode control. Such measures exemplarily comprise a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, a network listen mode measurement in accordance with the properties of the requested network listen mode measurement at the second base station, a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the network listen mode measurement, and network control and/or management on the basis of the result of the network listen mode measurement at the first base station. Such measures are exemplarily, but not exclusively, applicable in heterogeneous network deployments .

The measures according to exemplary embodiments of the present invention may be applied for any kind of network environment, such as for example for communication systems in accordance with 3GPP RAN1/RAN2/RAN3 standards and/or LTE standards of release 10/11/12/... (including LTE-Advanced and its evolutions) and/or UMTS standards and/or WCDMA standards and/or HSPA standards.

Even though the invention is described above with reference to the examples according to the accompanying drawings, it is to be understood that the invention is not restricted thereto. Rather, it is apparent to those skilled in the art that the present invention can be modified in many ways without departing from the scope of the inventive idea as disclosed herein.

List of acronyms and abbreviations

3GPP Third Generation Partnership Project BS Base Station elCIC enhanced ICIC eNB evolved NodeB (base station)

E-UTRAN Evolved UTRAN HARQ Hybrid Automatic Repeat Request

HSPA High Speed Packet Access

ICIC Inter-Cell Interference Coordination

LTE Long Term Evolution

NLM Network Listen Mode O&M Operation and Maintenance

PCI Physical Cell ID

RSRP Reference Signal Received Power

RSRQ Reference Signal Received Quality

SON Self Organizing Network UE User Equipment

UMTS Universal Mobile Telecommunications System

UTRAN Universal Terrestrial Radio Access Network

WCDMA Wideband Code Division Multiple Access

Claims

1. A method comprising making a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, acquiring a network listen mode report from the second base station at the first base station, said network listen mode report comprising a result of the requested network listen mode measurement, and utilizing the acquired result of the requested network listen mode measurement for at least one of network control and management at the first base station.

2. The method according to claim 1, wherein the properties of the requested network listen mode measurement comprise one or more of a time or time period for the network listen mode measurement, and at least one condition for the network listen mode measurement, and at least one type of the network listen mode measurement .

3. The method according to claim 2, wherein the at least one type of the network listen mode measurement comprises one or more of an intra-carrier pathloss measurement from one or more of neighboring base stations at the second base station, an inter-carrier pathloss measurement from one or more of neighboring base stations at the second base station, a timing measurement for one or more of neighboring base stations at the second base station, and at least one of a pathloss and a timing measurement at an entity other than the second base station.

4. The method according to claim 2 or 3, wherein the at least one condition for the network listen mode measurement comprises one or more of a load condition at the second base station, and a temporal condition of at least one of minimum and maximum periodicity of the requested network listen mode measurement .

5. The method according to any one of claims 1 to 4, wherein utilizing the acquired result of the requested network listen mode measurement comprises optimizing one or more of inter- cell interference control, power control settings, inter-cell time synchronization, neighbor cell relations, and handover and/or mobility settings.

6. The method according to any one of claims 1 to 5, further comprising controlling the network listen mode request in terms of at least one of frequency, timing and contents on the basis of one or more of a timing control at the first base station, status control at the first base station, network listen mode measurements from entities other than the second base station, and any report or message relating to the second base station.

7. The method according to any one of claims 1 to 6, wherein the method is operable at or by the first base station, and/or the first and second base stations are connected by a standardized logical interface such as a X2 interface, and/or the first and second base stations are located in a network of a heterogeneous network deployment, and/or the first base station comprises a base station of an overlay network layer, and the second base station comprises a base station of an underlay network layer.

8. A method comprising acquiring a network listen mode request from a first base station at a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, performing the requested network listen mode measurement in accordance with the acquired properties of the requested network listen mode measurement at the second base station, and making a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the performed network listen mode measurement.

9. The method according to claim 8, wherein the requested network listen mode measurement is performed in accordance with a time or time period for the network listen mode measurement .

10. The method according to claim 8 or 9, wherein the requested network listen mode measurement is performed in accordance with at least one type of the network listen mode measurement, said at least one type of the network listen mode measurement comprising one or more of an intra-carrier pathloss measurement from one or more of neighboring base stations at the second base station, an inter-carrier pathloss measurement from one or more of neighboring base stations at the second base station, a timing measurement for one or more of neighboring base stations at the second base station, and at least one of a pathloss and a timing measurement at an entity other than the second base station.

11. The method according to any one of claims 8 to 10, wherein the requested network listen mode measurement is performed in accordance with at least one condition for the network listen mode measurement, said at least one condition for the network listen mode measurement comprising one or more of a load condition at the second base station, and a temporal condition of at least one of minimum and maximum periodicity of the requested network listen mode measurement .

12. The method according to any one of claims 8 to 11, wherein the method is operable at or by the second base station, and/or the first and second base stations are connected by a standardized logical interface such as a X2 interface, and/or the first and second base stations are located in a network of a heterogeneous network deployment, and/or the first base station comprises a base station of an overlay network layer, and the second base station comprises a base station of an underlay network layer.

13. An apparatus comprising an interface configured to communicate with at least another apparatus, and a processor configured to cause the apparatus to perform: making a network listen mode request from a first base station to a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, acquiring a network listen mode report from the second base station at the first base station, said network listen mode report comprising a result of the requested network listen mode measurement, and utilizing the acquired result of the requested network listen mode measurement for at least one of network control and management at the first base station.

14. The apparatus according to claim 13, wherein the properties of the requested network listen mode measurement comprise one or more of a time or time period for the network listen mode measurement, and at least one condition for the network listen mode measurement, and at least one type of the network listen mode measurement .

15. The apparatus according to claim 14, wherein the at least one type of the network listen mode measurement comprises one or more of an intra-carrier pathloss measurement from one or more of neighboring base stations at the second base station, an inter-carrier pathloss measurement from one or more of neighboring base stations at the second base station, a timing measurement for one or more of neighboring base stations at the second base station, and at least one of a pathloss and a timing measurement at an entity other than the second base station.

16. The apparatus according to claim 14 or 15, wherein the at least one condition for the network listen mode measurement comprises one or more of a load condition at the second base station, and a temporal condition of at least one of minimum and maximum periodicity of the requested network listen mode measurement .

17. The apparatus according to any one of claims 13 to 16, wherein utilizing the acquired result of the requested network listen mode measurement comprises optimizing one or more of inter-cell interference control, power control settings, inter-cell time synchronization, neighbor cell relations, and handover and/or mobility settings.

18. The apparatus according to any one of claims 13 to 17, wherein the processor is further configured to cause the apparatus to perform: controlling the network listen mode request in terms of at least one of frequency, timing and contents on the basis of one or more of a timing control at the first base station, status control at the first base station, network listen mode measurements from entities other than the second base station, and any report or message relating to the second base station.

19. The apparatus according to any one of claims 13 to 18, wherein the apparatus is operable as or at the first base station, and/or the first and second base stations are connected by a standardized logical interface such as a X2 interface, and/or the first and second base stations are located in a network of a heterogeneous network deployment, and/or the first base station comprises a base station of an overlay network layer, and the second base station comprises a base station of an underlay network layer.

20. An apparatus comprising an interface configured to communicate with at least another apparatus, and a processor configured to cause the apparatus to perform: acquiring a network listen mode request from a first base station at a second base station, said network listen mode request comprising properties of a requested network listen mode measurement, performing the requested network listen mode measurement in accordance with the acquired properties of the requested network listen mode measurement at the second base station, and making a network listen mode report from the second base station to the first base station, said network listen mode report comprising a result of the performed network listen mode measurement.

21. The apparatus according to claim 20, wherein the processor is configured to cause the apparatus to perform the requested network listen mode measurement in accordance with a time or time period for the network listen mode measurement .

22. The apparatus according to claim 20 or 21, wherein the processor is configured to cause the apparatus to perform the requested network listen mode measurement in accordance with at least one type of the network listen mode measurement, said at least one type of the network listen mode measurement comprising one or more of an intra-carrier pathloss measurement from one or more of neighboring base stations at the second base station, an inter-carrier pathloss measurement from one or more of neighboring base stations at the second base station, a timing measurement for one or more of neighboring base stations at the second base station, and at least one of a pathloss and a timing measurement at an entity other than the second base station.

23. The apparatus according to any one of claims 20 to 22, wherein the processor is configured to cause the apparatus to perform the requested network listen mode measurement in accordance with at least one condition for the network listen mode measurement, said at least one condition for the network listen mode measurement comprising one or more of a load condition at the second base station, and a temporal condition of at least one of minimum and maximum periodicity of the requested network listen mode measurement .

24. The apparatus according to any one of claims 20 to 23, wherein the apparatus is operable as or at the second base station, and/or the first and second base stations are connected by a standardized logical interface such as a X2 interface, and/or the first and second base stations are located in a network of a heterogeneous network deployment, and/or the first base station comprises a base station of an overlay network layer, and the second base station comprises a base station of an underlay network layer.

25. A computer program product comprising computer-executable computer program code which, when the program is run on a computer, is configured to cause the computer to carry out the method according to any one of claims 1 to 12.

26. The computer program product according to claim 25, wherein the computer program product comprises a computer- readable medium on which the computer-executable computer program code is stored, and/or wherein the program is directly loadable into an internal memory of the processor.