Title Automated Configuration of Base Stations Field of the Invention

The present invention relates to an apparatus, method, system and computer program product for the automated configuration of base stations. In particular, the present invention re ^¬ lates to an apparatus, method, system and computer program product for automated configuration of base stations such as Home evolved Node Bs of enterprise femtocells.

Related background Art

Prior art which is related to this technical field can e.g. be found by the technical specifications TS 36.300 (current version: 10.0.0), TS 36.401 (current version 9.2.0), TS

36.420 (current version 9.0.0), and TS 36.423 (current ver ^¬ sion: 9.3.0) of the 3GPP.

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

3G: 3 ^rd Generation

3GPP: 3 ^rd Generation Partnership Project

ANR: Automatic Neighborhood Relation

AP: Application Protocol

CN: Core Network

CSG: Closed Subscriber Group

DL: Downlink

DSR: Detected Set Reporting

eNB: evolved Node B (eNode B)

HeNB: Home eNB HII : High Interference Indication

HO: Hand-over

ID: Identifier

IOI : Interference Overload Indication

IP: Internet Protocol

IE: Information Element

LTE : Long Term Evolution

LTE-A: Long Term Evolution Advanced

MNO: Mobile Network Operator

NCL: Neighboring Cell List

NLM: Network Listening Mode

UE: User Equipment

UL: Uplink In the field of to LTE/LTE-A and femtocells the enterprise usage of HeNBs and in particular their auto-configuration like Automated Neighborhood Relation (ANR) has recently be ^¬ come the target of intense consideration. It is assumed that HeNBs in enterprises will generate a high portion of revenues related to the concept of femtocells. Hence, the 3GPP and the "Femtoforum" experience many activities towards enhancements in a dense femtocell deployment in an enterprise scenario.

However, one problem observed in enterprise femtocell deploy- ment relates to cases of a massive femtocell roll-out where each base station has to have a configuration of Neighbouring Cell List (NCL) for HO purposes. Nowadays this is done manu ^¬ ally and often tuned for better performance via e.g. drive- test over long and repetitive live network measurements and off-line processing. In this connection a rather high amount of tedious work, time and money is needed for proper NCL con ^¬ figuration in enterprise scenario especially taking into ac ^¬ count the foreseen number of HeNBs to be deployed. Hence, an automated, quick and reliable NCL population method is urgently needed. A possible solution to NCL population in 3G is to enable De ^¬ tected Set Reporting (DSR) . As studies have shown (see

"Neighbor Cell Relation List and Physical Cell Identity Self- Organization in LTE", M. Amirijoo, F. Gunnarsson, H. Kallin, J. Moe, K. Zetterberg, Ericsson Research, ICC 2008 workshop proceedings, 2008; and "Self-optimizing Neighbor Cell List for UTRA FDD Networks Using Detected Set Reporting", D.

Soldani, I. Ore, Nokia Networks, IEEE, 2007), this has sev ^¬ eral drawbacks like e.g. initial high number of measurements to be taken, high signaling load due to frequent measure ^¬ ments, lower UE battery life and several failed HO attempts before the actual configuration final set-up. The same prin ^¬ ciples may apply to LTE ANR which may be time and resources consuming, taking into account that femto overlapping areas are quite small. Hence, users may relatively quickly and of ^¬ ten move from one cell to another.

Summary of the Invention It is an object of the present invention to overcome at least some of the drawbacks of the prior art.

According to a first aspect of the present invention, this is accomplished by an apparatus, comprising interference deter- mination means configured to determine an interference pat ^¬ tern transmitted by a communication terminal based on a cel ^¬ lular communication network related configuration of the communication terminal, wherein the determined interference pat ^¬ tern includes information on a transmission schedule of the communication terminal; interference pattern distribution means configured to initiate a wire connection based broad ^¬ cast distribution of the determined interference pattern; in ^¬ terference pattern match means configured to compare an in ^¬ terference pattern observed on a radio interface with an in- terference pattern broadcast on wire connection, based on a transmission schedule of the interference pattern broadcast on wire connection; and neighbor listing means configured to mark as a neighbor an originator of an interference pattern broadcast on wire connection in case the interference pattern match means determines a match between the interference pat- tern broadcast on wire connection of this originator and an interference pattern observed on a radio interface.

Modifications of the first aspect may be as follows. The apparatus according to the first aspect may be configured to be suitable for the automated configuration of base sta ^¬ tions .

The interference pattern match means may be further config- ured to initiate sending acknowledgement of a match between an interference pattern observed on a radio interface and an interference pattern broadcast on wire connection to the originator thereof; and the neighbor listing means may be further configured to mark as a neighbor an originator of an acknowledgement of a match between an interference pattern observed on a radio interface and an interference pattern broadcast on wire connection.

The interference pattern distribution means may be further configured to initiate the wire connection based broadcast distribution of the determined interference pattern by in ^¬ cluding information on the determined interference pattern in a high interference indication information element; the interference pattern match means may be further configured to initiate sending acknowledgement on a match between an interference pattern observed on a radio interface and an inter ^¬ ference pattern broadcast on wire connection to the origina ^¬ tor thereof by including information on the match in an interference overload indication information element; and the neighbor listing means may be further configured to assess a physical distance in a communication network configuration to the originator of the acknowledgement of a match between an interference pattern observed on a radio interface and an in ^¬ terference pattern broadcast on wire connection based on an interference level indicated in the interference overload in- dication information element.

The apparatus may further comprise communication network detection means configured to detect communication network ele ^¬ ments based on a wire connected internet protocol connection and to classify detected communication network elements ac ^¬ cording to an assessed physical distance in a communication network configuration based on a communication time evaluation, wherein the interference pattern distribution means may be further configured to initiate the wire connection based broadcast distribution of the determined interference pattern only with respect to a group of detected communication net ^¬ work elements which are classified to have a closest assessed physical distance. The neighbor listing means may be further configured to in ^¬ form a neighbor marking to the concerned neighbor or another neighbor, and to mark as a neighbor an originator of a neighbor marking information or another communication network element indicated in the neighbor marking information, based on the information content, as well as to acknowledge receipt of a neighbor marking information.

According to a second aspect of the present invention, the object is accomplished by an apparatus, comprising an inter- ference determination processor configured to determine an interference pattern transmitted by a communication terminal based on a cellular communication network related configuration of the communication terminal, wherein the determined interference pattern includes information on a transmission schedule of the communication terminal; an interference pat ^¬ tern distributor configured to initiate a wire connection based broadcast distribution of the determined interference pattern; an interference pattern comparator configured to compare an interference pattern observed on a radio interface with an interference pattern broadcast on wire connection, based on a transmission schedule of the interference pattern broadcast on wire connection; and a neighbor listing control processor configured to mark as a neighbor an originator of an interference pattern broadcast on wire connection in case the interference pattern match means determines a match be- tween the interference pattern broadcast on wire connection of this originator and an interference pattern observed on a radio interface.

Modifications of the second aspect of the present invention may correspond to the modifications of the first aspect.

According to a third aspect of the present invention, the ob ^¬ ject is accomplished by a Home evolved Node B, comprising an apparatus according to the first or second aspect of the pre- sent invention or any one of their modifications.

According to a fourth aspect of the present invention, the object is accomplished by a method, comprising determining an interference pattern transmitted by a communication terminal based on a cellular communication network related configuration of the communication terminal, wherein the determined interference pattern includes information on a transmission schedule of the communication terminal; initiating a wire connection based broadcast distribution of the determined in- terference pattern; comparing an interference pattern ob ^¬ served on a radio interface with an interference pattern broadcast on wire connection, based on a transmission schedule of the interference pattern broadcast on wire connection; and marking as a neighbor an originator of an interference pattern broadcast on wire connection in case a match is determined between the interference pattern broadcast on wire connection of this originator and an interference pattern observed on a radio interface.

Modifications of the fourth aspect may be as follows.

The method according to the fourth aspect may be configured to be suitable for the automated configuration of base sta ^¬ tions . The method may further comprise initiating sending acknowledgement of a match between an interference pattern observed on a radio interface and an interference pattern broadcast on wire connection to the originator thereof; and marking as a neighbor an originator of an acknowledgement of a match be- tween an interference pattern observed on a radio interface and an interference pattern broadcast on wire connection.

The initiating the wire connection based broadcast distribu ^¬ tion of the determined interference pattern may comprise in- eluding information on the determined interference pattern in a high interference indication information element, and the initiating sending acknowledgement on a match between an interference pattern observed on a radio interface and an in ^¬ terference pattern broadcast on wire connection to the origi- nator thereof may comprise including information on the match in an interference overload indication information element, while the method may further comprise assessing a physical distance in a communication network configuration to the originator of the acknowledgement of a match between an in- terference pattern observed on a radio interface and an in ^¬ terference pattern broadcast on wire connection based on an interference level indicated in the interference overload in ^¬ dication information element. The method may further comprise detecting communication network elements based on a wire connected internet protocol connection; and classifying detected communication network elements according to an assessed physical distance in a com ^¬ munication network configuration based on a communication time evaluation, wherein initiating the wire connection based broadcast distribution of the determined interference pattern may be performed only with respect to a group of detected communication network elements which are classified to have a closest assessed physical distance. The method may further comprise informing a neighbor marking to the concerned neighbor or another neighbor; marking as a neighbor an originator of a neighbor marking information or another communication network element indicated in the neighbor marking information, based on the information con- tent; and acknowledging receipt of a neighbor marking information .

The method according to the fourth aspect or any of its modi ^¬ fications may be performed by the apparatus according to the first or second aspect or suitable ones of their modifica ^¬ tions .

According to a fifth aspect of the present invention, the ob ^¬ ject is accomplished by a computer program product comprising computer-executable components which perform, when the pro ^¬ gram is run on a computer, determining an interference pattern transmitted by a communication terminal based on a cel ^¬ lular communication network related configuration of the communication terminal, wherein the determined interference pat- tern includes information on a transmission schedule of the communication terminal; initiating a wire connection based broadcast distribution of the determined interference pat ^¬ tern; comparing an interference pattern observed on a radio interface with an interference pattern broadcast on wire con- nection, based on a transmission schedule of the interference pattern broadcast on wire connection; and marking as a neighbor an originator of an interference pattern broadcast on wire connection in case a match is determined between the interference pattern broadcast on wire connection of this originator and an interference pattern observed on a radio interface.

Modifications of the fifth aspect may be as follows.

The computer program product according to the fifth aspect may be suitable for the automated configuration of base sta ^¬ tions .

The computer program product according to the fifth aspect may be embodied as a computer-readable storage medium.

Otherwise, modifications of the fifth aspect may correspond to the modifications of the fourth aspect.

It is to be understood that any of the above modifications can be applied singly or in combination to the respective as ^¬ pects to which they refer, unless they are explicitly stated as excluding alternatives.

Brief Description of the Drawings

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

Fig. 1 shows an apparatus according to certain embodiments of the present invention;

Fig. 2 shows a flow chart illustrating a method according to certain embodiments of the present invention; Fig. 3 shows an interference situation caused by a permitted UE when connecting with a CSG cell according to certain embodiments of the present invention; Fig. 4 shows a correlation of interference occurrence pat ^¬ terns according to certain embodiments of the present inven ^¬ tion;

Fig. 5 shows a further step in the correlation of interfer- ence occurrence patterns according to certain embodiments of the present invention; and

Fig. 6 shows mutual information exchange for acknowledging neighborship according to certain embodiments of the present invention.

Detailed Description of the preferred Embodiments

In the following, description is made to what are presently considered to be preferred embodiments of the present inven ^¬ tion. It is to be understood, however, that the description is given by way of example only, and that the described em ^¬ bodiments are by no means to be understood as limiting the present invention thereto.

For example, for illustration purposes, in some of the fol ^¬ lowing exemplary embodiments, automated configuration of base stations such as e.g. based on LTE-Advanced is described. However, it should be appreciated that these exemplary em- bodiments are not limited for use among these particular types of wireless communication systems, and according to further exemplary embodiments, the present invention can be applied also to other types of communication systems and ac ^¬ cess networks in which the problem of automated configuration of base stations occurs. Thus, certain embodiments of the present invention relate to mobile wireless communication systems, such as 3GPP LTE and 3GPP LTE-Advanced . In more detail, certain embodiments of the present invention are related to the configuration of an LTE eNB/HeNB and components thereof, or the like.

However, as indicated above, the present invention is not limited to eNB/HeNB, but other embodiments of the present in ^¬ vention are related to general base station nodes and compo- nents thereof.

Fig. 1 shows a principle configuration of an example for an apparatus according to certain embodiments of the present in ^¬ vention. One option for implementing this example for an ap- paratus according to certain embodiments of the present in ^¬ vention would be a component in a Home evolved Node B accord ^¬ ing to LTE.

Specifically, as shown in Fig. 1, the example for an appara- tus comprises an interference determination processor 11 configured to determine an interference pattern transmitted by a communication terminal based on a cellular communication network related configuration of the communication terminal, wherein the determined interference pattern includes informa- tion on a transmission schedule of the communication terminal. Further, the example apparatus comprises an interference pattern distributor 12 configured to initiate a wire connec ^¬ tion based broadcast distribution of the determined interfer ^¬ ence pattern. In addition, the example apparatus comprises an interference pattern comparator 13 configured to compare an interference pattern observed on a radio interface with an interference pattern broadcast on wire connection, based on a transmission schedule of the interference pattern broadcast on wire connection, and a neighbor listing control processor 14 configured to mark as a neighbor an originator of an interference pattern broadcast on wire connection in case the interference pattern comparator 13 determines a match between the interference pattern broadcast on wire connection of this originator and an interference pattern observed on a radio interface .

Moreover, in Fig. 1 is indicated an example of an advanta ^¬ geous modification, wherein the example apparatus additionally comprises a communication network element detector 15 configured to detect communication network elements based on a wire connected internet protocol connection and to classify detected communication network elements according to an assessed physical distance in a communication network configu ^¬ ration based on a communication time evaluation. In this case, the interference pattern distributor 12 is further con- figured to initiate the wire connection based broadcast dis ^¬ tribution of the determined interference pattern only with respect to a group of detected communication network elements which are classified to have a closest assessed physical dis ^¬ tance .

Fig. 2 shows a principle flowchart of an example for a method according to certain embodiments of the present invention. That is, as shown in Fig. 2, this method comprises determin ^¬ ing (SI) an interference pattern transmitted by a communica- tion terminal based on a cellular communication network related configuration of the communication terminal, wherein the determined interference pattern includes information on a transmission schedule of the communication terminal; initiat ^¬ ing (S2) a wire connection based broadcast distribution of the determined interference pattern; comparing (S3) an inter ^¬ ference pattern observed on a radio interface with an inter ^¬ ference pattern broadcast on wire connection, based on a transmission schedule of the interference pattern broadcast on wire connection; and marking (S4) as a neighbor an origi- nator of an interference pattern broadcast on wire connection in case a match is determined between the interference pat- tern broadcast on wire connection of this originator and an interference pattern observed on a radio interface.

As further shown in Fig. 2, example modifications would be e.g. prior to the above steps of the example method, detect ^¬ ing (SO) communication network elements based on a wire connected internet protocol connection, and classifying (SO) de ^¬ tected communication network elements according to an assessed physical distance in a communication network configu- ration based on a communication time evaluation. In this case, the initiating (S2) the wire connection based broadcast distribution of the determined interference pattern is per ^¬ formed only with respect to a group of detected communication network elements which are classified to have a closest as- sessed physical distance. Another example modification con ^¬ cerns an acknowledgment (S5) of neighbor marking after the step of marking (S4) as a neighbor.

One option for performing the example of a method according to certain embodiments of the present invention would be to use the apparatus as described above or a modification thereof which becomes apparent from the embodiments as de ^¬ scribed herein below. According to certain embodiments of the present invention, a new method of NCL configuration is presented which takes ad ^¬ vantage of the fact that the HeNBs in enterprise scenario are located close to each other, and are interconnected over a same IP sub-network. This method is further based on an in- terconnection of the HeNBs which for example could be by us ^¬ ing the X2 interface. However, this is not mandatory. Addi ^¬ tionally, the instant method according to certain embodiments of the present invention could be also used to set-up the di ^¬ rect X2 connection between the HeNBs in the first pi3.CG _/ cL S suming that the HeNBs have knowledge about the transport layer (TNL) address to be used when setting up the direct X2 connection. This knowledge could either be provided by con ^¬ figuration or acquired more dynamically by exploiting the fact that in enterprise deployments the HeNBs could detect each other using appropriate IP messaging.

According to certain embodiments of the present invention, the instant method comprises the following steps:

In a first step, the HeNBs may learn using e.g. IP protocol about the presence of others HeNBs in the same enterprise IP sub-network. Based thereon, the HeNBs can build-up an IP HeNB neighbors table, where HeNBs could be classified by e.g. the amount of time needed for a ping request to be sent and re ^¬ ceived or the amount of hops to reach a distant HeNB. The HeNBs shall memorize this information for the usage in subse ^¬ quent states.

Though, the HeNBs may not be able to estimate based on the IP measurements mentioned above their adjacent neighbors. How- ever, a UE terminal can be used to narrow down the area of search. For this purpose, once a permitted (i.e. allowed to use the enterprise CSG ID) terminal establishes connection with a HeNB, this cell shall broadcast over the X2-AP inter ^¬ face the High Interference Indication (HII) IE with a special information telling the recipients of this message to listen on their radio interface for a interference pattern matching the HII IE. Since the HII IE contains information about scheduling of the connected UE, other cells can match the interference observed and received within this IE. In case they match, the receiving cell shall memorize the HII IE originat ^¬ ing cell as a possible direct neighbor.

All cells where the above described interference observed on the radio interface and the interference described in the HII IE matched shall respond with an Interference Overload Indi ^¬ cation (IOI) IE with additional information indicating the match of received interferences. Based thereon, the receiving HeNB shall store the responding HeNB as direct neighbors. In addition, based on the interference level indicated within the IOI IE, the receiving HeNB is able to assess which send- ing parties are most probably closer and which farther away. This information can be used for optimizing the NCL .

Finally, a mutual exchange of information confirming the ad ^¬ dition on cells to the NCLs is conducted.

In the following, further certain embodiments of the present invention are described with respect to Figs. 3 to 6 which demonstrate either alternative features or further detail features with respect to the above description.

At the beginning of the HeNB deployment it is assumed that the NCL are empty except neighbors that are discovered in Network Listening Mode (NLM) , i.e. overlaying macro cells and neighboring HeNBs which are close enough to be mutually heard.

The HeNBs can discover all other HeNBs in the same

sub-network over IP. The HeNBs could be classified e.g. by using the same CSG ID.

As depicted in Fig. 3, a permitted UE connects with a CSG cell of the enterprise (see Fig. 3, cell #1 - serving cell) . This connection causes interferences to other HeNBs (i.e. #2 and #4), since those cells are in direct vicinity to each other.

As illustrated in Fig. 4, the serving HeNB (#1) is scheduling the UE accordingly, and sends load information using the X2- AP interface with the IE High Interference Indication (HII) . According to certain embodiments of the present invention, however, this message is extended to indicate that its pur- pose in this case is to discover cell neighbors. Based on this information the interferences receiving party can corre ^¬ late the interferences occurrence pattern with the scheduling pattern received in the HII IE. If those interferences match, then they must come from the same UE . Hence, those cells must be close to each other.

Fig. 5 shows that the nodes receiving interferences over the radio interface (i.e. #2 and #4), after identifying as de- scribed above that they may be close to node #1, can answer with UL Interference Overload Indication (IOI) IE, which, ac ^¬ cording to certain embodiments of the present invention, can be modified according to needs. This IE contains the level of observed interferences. Hence, based thereon the receiving HeNB (#1) can estimate which HeNB might be closer or farther away. Other HeNBs which did not see interferences or where the interferences occurrence pattern did not match with the scheduling pattern received in HII IE are not responding with the IOI IE (like HeNB #3 of Fig. 5) .

Based thereon, and as indicated in Fig. 6, the HeNBs exchange mutual information in order to add their neighbors to their NCL, (i.e. for example HeNB #1 adds HeNB #2 and #4 to his NCL, HeNB #4 adds HeNB#2, and HeNB #2 adds HeNB #4 to his NCL) a new IE is exchanged to command HeNB #2 and #4 to add

HeNB #1 to NCL, and the neighbors are acknowledged based on a new information element.

A great advantage of the above described certain embodiments of the present invention is the potential speed of the solu ^¬ tion and the minimization of signaling. Since a femtocell roll-out and deployment in enterprise environment should be quick and represent an automated process without exhausting configuration processes, this solution helps to mitigate the process of automated neighbor list configuration. The method according to the above described certain embodiments of the present invention enables to configure neighbors quicker and without additional, time and battery life consuming, measure ^¬ ments done by UEs. This can be highly important in an envi ^¬ ronment where base station coverage overlapping areas are quite small, and which may thus result in many failed HOs .

What can be also important is that, since X2 signaling can be used for the discovery process, the signaling required by this process is fully hidden from the Mobile Network Operator (MNO) network, thus minimizing the Core Network (CN) signal- ing load. Accordingly, the above described certain embodi ^¬ ments of the present invention represent a valuable add-on to ANR neighbor discovery processes in LTE/LTE-A for enterprise environments . According to further certain embodiments of the present in ^¬ vention the above described methods and related implementa ^¬ tions in HeNBs could be used as an enterprise extension to existing ANR process e.g. according to 3GPP TS 36.300 with potential additional changes to specifications describing X2 messages (e.g. 3GPP TS 36.423) and HeNBs behavior upon recep ^¬ tion of this new message.

As indicated above, implementation examples for certain embodiments of the present invention include base station equipment capable of automated configuration such as LTE/LTE- Advanced HeNB, but are not limited thereto.

According to the above description, it should thus be apparent that exemplary embodiments of the present invention pro- vide, for example from the perspective of a network element such as an evolved Node B (eNB) /Home evolved Node B (HeNB) or a component thereof, an apparatus embodying the same, a method for controlling and/or operating the same, and computer program(s) controlling and/or operating the same as well as mediums carrying such computer program (s) and forming computer program product (s) . For example, described above are apparatuses, methods and computer program products capable of automated configuration of a base station.

Implementations of any of the above described blocks, appara ^¬ tuses, systems, techniques or methods include, as non limit ^¬ ing examples, implementations as hardware, software, for ex ^¬ ample in connection with a digital signal processor, firm- ware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

What is described above is what is presently considered to be preferred embodiments of the present invention. However, as is apparent to the skilled reader, these are provided for il ^¬ lustrative purposes only and are in no way intended that the present invention is restricted thereto. Rather, it is the intention that all variations and modifications be included which fall within the spirit and scope of the appended claims .