WO2014161149A1

WO2014161149A1 - Mechanism for identifying a communication cell

Info

Publication number: WO2014161149A1
Application number: PCT/CN2013/073630
Authority: WO
Inventors: Pengfei Sun; Erlin Zeng; Haiming Wang; Wei Bai; Jing HAN
Original assignee: Broadcom Corporation
Priority date: 2013-04-02
Filing date: 2013-04-02
Publication date: 2014-10-09

Abstract

There is proposed a mechanism for cell identification or discovery. The cell transmits a control signal for identification which is received and processed by a UE. Depending on the operation state of the cell, which is one of an active state and a dormant state, the control signal is configured according to a first type of identification signaling for the active state and a second type of identification signaling for the dormant state, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling. Thus, a dormant cell state or an active cell state can be identified, wherein a communication quality measurement mode is adapted according to the detected cell state.

Description

MECHANI SM FOR I DENTI FY I NG A CO MM UN I CAT I ON CELL

DESCRIPTION

BACKGROUND OF THE INVENTION

Field of the invention The present invention relates to a mechanism for identifying communication cells in a communication network. In particular, the present invention is directed to apparatuses, methods and computer program products by means of which a cell discovery or identification procedure can be conducted wherein also a current operation state such as an active state or a dormant state of the cell (i.e. of the communication network control element of the cell) is considered.

Related background Art Prior art which is related to this technical field can e.g. be found in technical specifications according to 3GPP TS 36.211 (e.g. version 10.1.0).

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

BS: base station

CPU: central processing unit

CRS common reference signal

DL: downlink

DTX: discontinuous transmission

eNB: evolved node B

ID: identification

LTE: Long Term Evolution

LTE-A: LTE Advanced

Ml B: master information block NCT: new carrier type

PDCCH: physical downlink control channel

PDCH: physical discovery channel

PRB: physical resource block

PSS: primary synchronization signal

RB: resource blocks

RF: radio frequency

RS: reference signal

SSS: secondary synchronization signal

UE: user equipment

UL: uplink

In the last years, an increasing extension of communication networks, e.g. of wire based communication networks, such as the Integrated Services Digital Network (ISDN), DSL, or wireless communication networks, such as the cdma2000 (code division multiple access) system, cellular 3rd generation (3G) communication networks like the Universal Mobile Telecommunications System (UMTS), enhanced communication networks based e.g. on LTE, cellular 2nd generation (2G) communication networks like the Global System for Mobile communications (GSM), the General

Packet Radio System (GPRS), the Enhanced Data Rates for Global Evolutions (EDGE), or other wireless communication system, such as the Wireless Local Area Network (WLAN), Bluetooth or Worldwide Interoperability for Microwave Access (WiMAX), took place all over the world. Various organizations, such as the 3rd Generation Partnership Project

(3GPP), Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN), the International Telecommunication Union (ITU), 3rd Generation Partnership Project 2 (3GPP2), Internet Engineering Task Force (IETF), the IEEE (Institute of Electrical and Electronics Engineers), the WiMAX Forum and the like are working on standards for telecommunication network and access environments.

A new approach for further developing wireless communication networks is the introduction of a so-called new carrier type (NCT) for LTE based networks. NCT allows it to enhance system spectrum efficiency and to reduce network energy consumption, wherein improvement in both small cells (e.g. in a heterogeneous network architecture) and macro cells is achievable. In other words, some of the main motivations for NCT implementation are to reduce energy consumption and to reduce interference e.g. due to common reference signal transmission by partially loaded or unloaded cells.

For implementation of NCT, also the behaviour of the cells, e.g. of corresponding communication network control elements such as eNBs is to be adapted. For example, the operation state of an eNB can be switched between an active state where full communication performance is available and a dormant state where only a limited communication performance is provided but power consumption can be reduced (also referred to as dual dormant/active state). That is, it is contemplated to allow a dual dormant/active state of the cell (e.g. of the eNB thereof) which means a DTX like eNB behaviour (e.g. with long DTX cycles). As a matter of course, a communication element such as a UE communicating with the cell is to be adapted accordingly.

That is, in a network implementing NCT, the cell is configured to be either in an active state or in a dormant state. That is to say, the NCT can adopt an active state or a dormant state in which the transmission activity is reduced and RF can be turned off, in order to save power.

Fig. 2 shows examples for possible dormant state behaviour in a corresponding cell (i.e. of the NCT used in the corresponding cell).

Specifically, Fig. 2 shows three options 1 to 3 for a signalling of radio frames over the time, where signal transmission in unloaded cells can be turned off.

In option 1, a so-called reduced CRS NCT is shown. CRS are used by a communication element, for example, for determining parameters necessary for establishing a connection, such as a phase reference for demodulation of DL control channels and for conducting communication quality level measurements, e.g. for generating channel state information feedback.

As shown by corresponding lines in the illustration of option 1 in Fig illustrating a CRS transmission phase, the carrier transmits the CRS non-continuous manner instead of using a continuous transmission (which is the usual way in a legacy carrier scenario, for example). Consequently, the cell (i.e. the communication network control element like an eNB) is able to turn off the RF during the CRS free periods (of course provided that no DL transmission is scheduled, i.e. when the cell is unloaded).

In option 2, a dormant mode of unloaded cells is shown. The upper graph illustrates a radio frame structure in an active state (corresponding to a fully loaded cell in a common case, i.e. backward compatibility is given). However, instead of defining a rigid CRS reduction pattern (like in option 1), the cell (e.g. the eNB) can enter a dormant state (lower graph). During this period of the dormant state, the eNB transmits only a discovery signal or cell identification signal (indicated by double-lined boxes). The cell identification signal (cell ID) is transmitted periodically and allows a receiving UE to detect the (dormant) cell. It is to be noted that the eNB can transmit the cell identification signal also during the active state.

In option 3, the dormant mode of unloaded cells according to option 2 and the reduced CRS scheme according to option 1 are combined. That is, in the active state illustrated again in the upper graph, the active state is depicted, while the lower graph illustrates the dormant state. As can be seen in comparison to option 2, in option 3, the CRS transmission in the active state is reduced so that less energy is consumed, while in the dormant phase only the cell ID is transmitted, as in option 2.

SUMMARY OF THE INVENTION

Examples of embodiments of the invention provide an apparatus, method and computer program product by means of which a discovery or identification of a cell is possible, wherein an operation state of the cell (i.e. dormant state or active state) can be considered for the further processing, such as for conducting a communication quality level measurement.

This is achieved by the measures defined in the appended claims. According to an example of an embodiment of the proposed solution, there is provided, for example, an apparatus comprising at least one processor; and at least one memory including computer program code; wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to perform an identification signaling configuration function arranged to configure a first type of identification signaling for an active operation state of a communication network control element and a second type of identification signaling for a dormant operation state of a communication network control element, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling, and a control signal transmission function configured to cause a transmission of a control signal for identification of a communication cell according to the first type of identification signaling or the second type of identification signaling, depending on an operation state of the communication network control element.

Furthermore, according to an example of an embodiment of the proposed solution, there is provided, for example, a method comprising configuring a first type of identification signaling for an active operation state of a communication network control element and a second type of identification signaling for a dormant operation state of a communication network control element, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling, and causing a transmission of a control signal for identification of a communication cell according to the first type of identification signaling or the second type of identification signaling, depending on an operation state of the communication network control element.

In addition, according to a further example of an embodiment of the proposed solution, there is provided, for example, an apparatus comprising at least one processor; and at least one memory including computer program code; wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to perform a control signal receiving and processing function configured to receive and process a control signal for identification of a communication cell, a cell identification function configured to identify a communication cell on the basis of the control signal, and a cell state determining function configured to determine an operation state of the communication cell as being one of an active operation state and a dormant operation state on the basis of a type of identification signaling used for the control signal, wherein a first type of the identification signaling is configured for the active operation state of the communication network control element and a second type of the identification signaling is configured for the dormant operation state of the communication network control element, at least one of communication settings and parameters of the first type of the identification signaling being different to the second type of identification signaling.

Furthermore, according to a further example of an embodiment of the proposed solution, there is provided, for example, a method comprising receiving and processing a control signal for identification of a communication cell, identifying a communication cell on the basis of the control signal, and determining an operation state of the communication cell as being one of an active operation state and a dormant operation state on the basis of a type of identification signaling used for the control signal, wherein a first type of the identification signaling is configured for the active operation state of the communication network control element and a second type of the identification signaling is configured for the dormant operation state of the communication network control element, at least one of communication settings and parameters of the first type of the identification signaling being different to the second type of identification signaling.

In addition, according to some examples of embodiments, there is provided, for example, a computer program product for a computer, comprising software code portions for performing the steps of the above defined methods, when said product is run on the computer. The computer program product may comprise a computer-readable medium on which said software code portions are stored. Furthermore, 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 some example embodiments of the invention, it is possible to provide an improved mechanism for identifying a communication cell, wherein an apparatus, a method and computer program product can be provided by means of which a discovery or identification of a cell is possible while an operation state of the cell (i.e. dormant state or active state) is considered, for example for a further processing, such as for conducting a communication quality level measurement in a suitable manner. For example, according to some examples of embodiments of the invention, a cell (i.e. a communication network control element such as an eNB thereof) is able to change between an active and a dormant state while it is ensured that a communication element such as a UE can efficiently carry out a cell identification or discovery, a determination of the current eNB state and a corresponding adaptation of a measurement mode for a communication quality level (adapted according to the respective operation state). Furthermore, an improved energy efficiency of the communication network control element such as of the eNB can be achieved while the UE is not impacted.

The above and still further objects, features and advantages of the some embodiments of the invention will become more apparent upon referring to the description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows an example signaling diagram illustrating a cell identification process in a communication network structure according to some examples of embodiments of the invention.

Fig. 2 shows diagrams illustrating radio frame examples in active/dormant operation states. Fig. 3 shows diagrams illustrating antenna port configurations used in a cell identification process according to some examples of embodiments of the invention.

Figs. 4a and 4b show diagrams illustrating radio frame examples in a dormant operation state according to some examples of embodiments of the invention.

Figs. 5a and 5b show diagrams illustrating radio frame examples in a dormant operation state according to some examples of embodiments of the invention.

Fig. 6 shows a diagram illustrating a radio frame example in active and dormant operation states according to some examples of embodiments of the invention.

Fig. 7 shows a flowchart illustrating a cell identification procedure conducted by a communication network control element according to some examples of embodiments of the invention.

Fig. 8 shows a flowchart illustrating a cell identification procedure conducted by a communication element according to some examples of embodiments of the invention.

Fig. 9 shows a block circuit diagram of a communication network control element including processing portions conducting functions according to some examples of embodiments of the invention.

Fig. 10 shows a block circuit diagram of a communication element including processing portions conducting functions according to some examples of embodiments of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS In the following, some examples and some embodiments of the present invention are described with reference to the drawings. For illustrating the present invention, some examples and embodiments will be described in connection with a cellular communication network based on a 3GPP LTE or LTE-A system comprising one or more communication cells controlled by a

(respective) communication network control element, such as an eNB, with which a communication element such as a UE is able to communicate. However, it is to be noted that the present invention is not limited to an application using such a type of a communication system, but is also applicable in other types of communication systems, such as a 3GPP based

UMTS communication system, a WCDMA system etc..

A basic system architecture of a communication network where some examples of embodiments of the invention are applicable may comprise a commonly known architecture of one or more communication systems comprising a wired or wireless access network subsystem and a core network. Such an architecture may comprise one or more access network control elements, radio access network elements, access service network gateways or base transceiver stations, such as a base station or eNB, which control a coverage area also referred to as a cell and with which a communication element or terminal device such as a UE or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a UE or attached as a separate element to a UE, or the like, is capable to communicate via one or more carriers and channels for transmitting several types of data. Furthermore, core network elements such as gateway network elements, policy and charging control network elements, mobility management entities and the like may be comprised.

The general functions and interconnections of the described elements, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof is omitted herein. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from a communication element like a UE or a communication network control element like an eNB etc., besides those described in detail herein below.

Furthermore, the described network elements, such as communication elements like UEs, communication network control elements like base stations, access nodes, eNBs, and the like, as well as corresponding functions as described herein may be implemented by software, e.g. by a computer program product for a computer, and/or by hardware. In any case, for executing their respective functions and/or algorithms, correspondingly used devices, nodes or network elements may comprise several means and components (not shown) which are required for control, processing and communication/signaling functionality. Such means may comprise, for example, one or more processor units including one or more processing portions for executing instructions, programs and for processing data, memory means for storing instructions, programs and data, for serving as a work area of the processor or processing portion and the like (e.g. ROM, RAM, EEPROM, and the like), input means for inputting data and instructions by software (e.g. floppy disc, CD-ROM, EEPROM, and the like), user interface means for providing monitor and manipulation possibilities to a user (e.g. a screen, a keyboard and the like), interface means for establishing links and/or connections under the control of the processor unit or portion (e.g. wired and wireless interface means, an antenna, etc.) and the like. It is to be noted that in the present specification processing portions should not be only considered to represent physical portions of one or more processors, but may also be considered as a logical division of the referred processing tasks performed by one or more processors.

As described above, in a network implementing NCT, the cell can be configured to be in an active state or in a dormant state, wherein Fig. 2 shows examples for possible dormant state behaviour in a corresponding cell, i.e. that a signal transmission in unloaded cells can be turned off.

A possible way in the options as shown in Fig. 2 to introduce the cell identification signal is to re-use specific signalings on legacy channels, such as synchronization signals used for enabling a time and frequency synchronization between the cell and a UE in a cell search or discovery phase, such as the PSS/SSS, reference signals such as the CRS etc.. The eNB could transmit these legacy signals during the cell identification period in the dormant state and turns off the RF during the remaining time.

However, in such a case, the UE is not able to distinguish whether the cell is in active or dormant state since the same cell identification signals are transmitted in both the active and the dormant state in the same manner (see e.g. option 2 or 3, where the cell ID is sent in both states in the same way). That is, it is not possible for the UE to identify whether the cell in question is active or not. Moreover, also the measurement of the communication quality level of the cell is impacted. For example, when a dormant cell is listened to by the UE, the UE conducts a measurement in a phase where the cell is again in the dormant state. Hence, in case the UE does not notice the end of the cell identification period and hence the beginning of the dormant state, the measurement result is tampered.

Therefore, according to some examples of embodiments of the invention, a cell identification procedure is proposed in which the cell identification signaling is adapted so as to enhance the applicability of the dormant state of a cell. That is, according to some examples of embodiments of the invention, signaling configuration and transmission procedures, e.g. physical layer signal patterns as well as associated procedures and controls are provided which are usable for a cell identification procedure wherein requirements for a processing in case of a dormant state of the cell are considered. By means of these procedures, an enhanced identification and measurement performance is achievable, while also an active/dormant state indication can be provided. With regard to Fig. 1 , a signaling diagram illustrating a general configuration of a communication network is shown where some examples of embodiments of the invention are applicable. It is to be noted that the structure indicated in Fig. 1 shows only those devices, network elements and parts which are useful for understanding principles underlying some examples of embodiments of the invention. As also known by those skilled in the art there may be several other network elements or devices involved in a connection between the communication element (UE) and the network (i.e. the communication network control element or eNB) which are omitted here for the sake of simplicity.

In Fig. 1, reference sign 10 denotes a communication element or terminal device such as a UE or the like which is capable of communicating with the communication network.

Reference sign 20 denotes a communication network control element such as a base station or eNB controlling a communication area or cell. The UE 10 communicates with the eNB 20 via one or more communication or data paths.

According to some examples of embodiments of the invention, an improved mechanism for identifying the cell (i.e. the eNB 20) at the side of the UE 10 is provided where the operation state of the cell (active or dormant) is also considered.

As indicated in Fig. 1 , as a first stage or step, the eNB 20 transmits (e.g. broadcasts) a control signal which is usable for identifying the cell, e.g. in a discovery process or the like. The control signal is provided with suitable information for indicating whether the eNB 20 is in an active operation state or in a dormant state. That is, for example, the control signal is based on e.g. a first type of identification signaling used for an active cell state or a second type of identification signaling used for a dormant cell state.

In step S20, the UE 10 processes a received control signal for conducting an identification or discovery process for identifying the cell of eNB 20.

In step S30, a determination is made in the UE 10 as to whether the cell from which the cell identification is received is in an active state or in a dormant state. Depending on this determination, a further processing in the UE 10 is controlled which is executed in step S40. For example, a procedure for measuring a communication quality level based on CRS comprised in the signaling from the eNB 20 is conducted in step S40. Alternatively or additionally, according to some examples of embodiments of the invention, the UE 10 reports the detected state change to other network elements. For example, the detected state of a cell is reported to a serving cell (serving eNB) to which the UE 10 is currently connected, e.g. in case the detected cell is a neighboring cell of the serving cell. Furthermore, according to some further examples of embodiments of the invention, a detected change of the state of a cell is reported from the UE 10 to other cells, such as the serving cell. The reporting may be triggered, for example, by an initial detection of a cell (and hence of a corresponding cell state), upon request from another cell (when a serving cell instructs the UE 10 to inform about known cell state of neighboring cells, for example), in predetermined intervals, or triggered by other events.

In the following, a description is provided for explaining further details of a cell identification procedure according to some examples of embodiments of the invention.

According to some examples of embodiments of the invention, the identification signaling used in the control signal in step S10 is based on control channels or signals already used for cell ID purposes, i.e. legacy channels or the like. For example, according to some examples of embodiments of the invention, cell identification signals transmitted by the eNB in dormant state are based on legacy channels and signals which are also used in the active state. For example, according to some examples of embodiments of the invention, synchronization signals such as PSS/SSS are used. According to some further examples of embodiments of the invention, reference signals such as CRS etc. are used.

According to some examples of embodiments of the invention, for providing an indication of the operation state, i.e. for differentiating between an active state and a dormant state, the correspondingly used legacy channels apply in the dormant state different configurations, sequences, or patterns. Furthermore, according to some examples of embodiments of the invention, when transiting to the dormant state, the (different) configurations, sequences, or patterns are adapted in such a manner that a higher signal density is achieved.

For example, according to some examples of embodiments of the invention, as indicated in Fig. 3, an antenna port configuration used for transmitting the control signal can be adapted according to the operation state, i.e. an identification signaling can be configured correspondingly.

Fig. 3 shows diagrams illustrating antenna port configurations used in a cell identification process according to some examples of embodiments of the invention. In detail, a cell specific reference symbol arrangement for respective antenna ports is shown. Boxes indicating an "R" parameter are assumed to be resource elements used for reference symbols on the respective antenna port

For example, the antenna port configuration for the CRS is e.g. 1, 2 and 4 ports (antenna ports 0 to 3) as in conventional LTE systems (based on the eNB capability and traffic needs). The number of antenna ports being available may be different to that numbers. In the upper half of Fig. 3, an antenna port configuration with 2 antenna ports is assumed for transmission in the active state.

According to some examples of embodiments of the invention, when the cell (i.e. the eNB 20) is in the dormant state, the antenna port configuration is such that always the maximum number of antenna ports is selected. That is, in the LTE case as shown in lower half of Fig. 3, the CRS are always configured to use all 4 antenna ports irrespective of the CRS port configuration used in the active state (i.e. 2, as indicated in the upper half of Fig.3). Since in the dormant state no traffic is served, all available antenna ports can be used. Thus, according to some examples of embodiments of the invention, the eNB 20 is able to configure all (4) antenna ports which increases the CRS density.

According to some further examples of embodiments of the invention, as will be explained in connection with Fig. 4, a transmission duration of a component used for identifying the cell is set to a different amount than a transmission duration of a component used for quality level measurement. For example, as indicated in Figs. 4a/b, which show diagrams illustrating radio frame examples in a dormant operation state according to some examples of embodiments of the invention, when synchronization signals such as PSS and SSS (wherein the SSS may be split in two different SSS, i.e. SSS1 and SSS2, for example) are used as a signal component used for identification of the cell, and a reference signal such as CRS is used for communication quality level measurement, the transmission duration of the CRS to the PSS/SSS duration is set such that it is possible for the UE to measure the quality level after the PSS/SSS detection, i.e. to provide sufficient time therefore. That is, a duration offset of a cell identification or discovery signal and the CRS is adjusted.

Fig. 4a shows a first alternative of such a configuration using a duration offset. During a cell ID signal duration (i.e. during the control signal), CRS containing reference symbols (indicated by the shaded area) are transmitted. Furthermore, synchronization signals (here PSS and SSS) for cell identification are transmitted, wherein the above described duration offset can be seen. Fig. 4b shows a further alternative similar to that of Fig. 4a wherein the time of the PSS/SSS signal is shifted. In any of the alternatives shown in Figs. 4a/b, the CRS duration is different from the duration of the cell discovery signal based on the PSS/SSS. The offset is set such that irrespective of when the UE 10 detects the cell discovery signals (here the PSS/SSS), there is sufficient time to perform quality level measurement based on the CRS. According to some examples of embodiments of the invention, when the eNB 20 configures the duration offset between the CRS duration and the duration of the cell discovery signal based on the PSS/SSS, it sends corresponding configuration information to the UE 10 so as to enable the UE

10 to conduct e.g. the communication quality level measurement under consideration of the duration of the CRS portion (which is derived from the duration offset information). That is, according to some examples of embodiments of the invention, the eNB 20 transmits configuration information related to the cell discovery/identification at the UE side wherein the configuration information indicate the duration offset and also other information, such as related cell identification cycle information, etc. The configuration information is transmitted according to some examples of embodiments of the invention with the control signal, or according to some other examples of embodiments of the invention by a separate signaling.

According to some examples of embodiments of the invention, during the dormant state, the (legacy) signals or channels used for the cell identification, such as the PSS/SSS/CRS, use empty resources of a transmission subframe. By means of this, a signal density is increased.

It is to be noted that according to some further examples of embodiments of the invention, instead of using the above described PSS/SSS, also other legacy signals or channels are usable as a component for the cell identification (cell discovery) signal, for example CRS, MIB, and the like. In this connection according to some further examples of embodiments of the invention, it is to be noted that for indicating the respective operation state, a special pattern of the signal is used to indicate the active/dormant states. Alternatively or additionally, special information bits are included in the signal to indicate the active/dormant states. For example, according to some examples of embodiments of the invention, when being in the dormant state, the PSS/SSS/ CRS/ Ml B used for the cell ID information provision has the special pattern or contains the special information bits (in contrast to an active state where this special pattern or information is not used, for example).

According to some further examples of embodiments of the invention, the identification signaling used in the control signal in step S10 is based on a dedicated cell discovery channel, such as PDCH. That is, the eNB 20 configures the cell identification signal of the basis of a new dedicated cell discovery signals, such as PDCH, in combination with CRS. According to some examples of embodiments of the invention, the PDCH and CRS pattern is designed to be transmitted during the active state while dormant/active state indication is possible and quality level measurement are enabled. For example, according to some examples of embodiments of the invention, there is a coordination between the cell ID and resources used for legacy channels. For example, the cell identification signal is punctured by the legacy channels, such as CRS, PDCCH, PSS/SSS, MIBs. Hence, a transmission of the cell ID also during the active state is possible.

According to some examples of embodiments of the invention, for providing an indication of the operation state, i.e. for differentiating between an active state and a dormant state, the correspondingly used dedicated cell discovery channel applies in the dormant state different configurations, sequences, or patterns. That is, during the dormant state, the cell discovery signal adopts different sequences, patterns etc. than that during the active state so that the active/dormant state can be indicated via the identification signal.

According to some examples of embodiments of the invention, as described in connection with Fig. 5, the length of the cell discovery signals (i.e. a component used for identifying the cell) is set to a different amount than a transmission duration of a component used for quality level measurement (e.g. CRS) to allow a communication quality level measurement after e.g. a PDCH detection. For example, as indicated in Figs. 5a/b, which show diagrams illustrating radio frame examples in a dormant operation state according to some examples of embodiments of the invention, when a PDCH is used as a signal component used for identification of the cell, and a reference signal such as CRS is used for communication quality level measurement, the transmission duration of the CRS to the PDCH duration is set such that it is possible for the UE to measure the quality level after the PDCH detection, i.e. to provide sufficient time therefore. That is, a duration offset of a cell identification or discovery signal and the CRS is adjusted.

Fig. 5a shows a first alternative of such a configuration using a duration offset. During a cell ID signal duration (i.e. during the control signal), CRS containing reference symbols (indicated by the shaded area) are transmitted. Furthermore, a PDCH for cell identification is transmitted, wherein the above described duration offset can be seen. Fig. 5b shows a further alternative similar to that of Fig. 5a wherein the time of the PDCH transmission is shifted.

In any of the alternatives shown in Figs. 5a/b, the CRS duration is different from the duration of the cell discovery signal based on the PDCH. The offset is set such that irrespective of when the UE 10 detects the PDCH, there is sufficient time to perform quality level measurement based on the CRS.

Furthermore, according to some examples of embodiments of the invention, when the eNB 20 configures the duration offset between the CRS duration and the duration of the cell discovery signal based on the PDCH, it sends corresponding configuration information to the UE 10 so as to enable the UE 10 to conduct e.g. the communication quality level measurement under consideration of the duration of the CRS portion (which is derived from the duration offset information). That is, according to some examples of embodiments of the invention, the eNB 20 transmits configuration information related to the cell discovery/identification at the UE side wherein the configuration information indicate the duration offset and also other information, such as related cell identification cycle information, etc. The configuration information is transmitted according to some examples of embodiments of the invention with the control signal, or according to some other examples of embodiments of the invention by a separate signaling. In the above description, examples of embodiments of the invention are described which are mainly directed to the control signal configuration. In the following, examples of embodiments of the invention are described which are related to a processing of the signalings on the UE side, i.e. to a behavior of the UE 10 when receiving a control signal. Furthermore, a processing related to a cell discovery and active/dormant state indication as well as a quality measurement in case of a dormant state cell is described.

According to some examples of embodiments of the invention, as indicated in Fig. 1 at step S20, when the UE 10 receives the control signal which includes a cell identification cycle, it identifies the corresponding cell.

In case the control signal is generated with regard to the above described offset of the discovery signal duration and the CRS duration, i.e. in case the duration offset is applied, according to some examples of embodiments of the invention, the UE 10 performs a communication quality level measurement for an indicated duration upon the detection of the cell discovery signals. According to some examples of embodiments of the invention, the information contained in the configuration information transmitted from the eNB 20, such as an indication of the duration offset cell identification cycle information, etc., is used by the UE 10 for the communication quality level measurement. That is, for example, in case a dormant state cell is discovered, the communication quality level measurement is conducted for the duration where the CRS is provided, while the remaining time where e.g. no transmission is done by the dormant cell (and hence no CRS is provided) is not considered for the measurement.

According to some further examples of embodiments of the invention, once the UE 10 is configured, the UE 10 searches for both dormant and active cells based on corresponding cell identification signals. In case the UE 10 detects a dormant cell, the UE 10 performs a communication quality level measurement in CRS duration (i.e. when CRS are actually transmitted). Otherwise, in case an active cell is detected, the UE 10 performs the measurement permanently, i.e. for every CRS symbol.

According to some further examples of embodiments of the invention, the UE 10 continuously checks the active/dormant state indication of a discovered cell. That is, the operation state indication provided e.g. via PSS/SSS/CRS/MIB/PDCH is monitored so as to detect a possible operation state change, i.e. a change from active to dormant state or vice versa. When the operation state change is detected, the UE 10 may adapt the measurement mode correspondingly, i.e. it changes the measurement behavior for the communication quality level, on the basis of the now detected active/dormant state. Furthermore, according to some examples of embodiments of the invention, the UE 10 reports the detected state change to other network elements. For example, the detected change of a state of a cell is reported to a serving cell (serving eNB) to which the UE 10 is currently connected, e.g. in case the detected cell is a neighboring cell of the serving cell.

Furthermore, according to some further examples of embodiments of the invention, the detected state of a cell is reported from the UE 10 to other cells, such as the serving cell, also when the state is initially detected, upon request from another cell, in predetermined intervals or triggered by other events.

Fig. 6 shows a diagram illustrating a radio frame example in active and dormant operation states according to some examples of embodiments of the invention. Specifically, Fig. 6 is used for illustrating the UE processing depending on the respectively received control signal, in particular when the operation state of the eNB 20 changes (here from dormant state to active state). It is to be noted that the control signal configuration can be any of the configurations described in the above examples of embodiments of the invention, for example. At the beginning, when the eNB 20 is in the dormant state, a cell identification signal configured for indicating the dormant state is transmitted. That is, in a cell identification cycle, during a first period, a control signal comprising a cell ID component (black part) and a component for quality level measurement (hatched part) is sent periodically, wherein in phases between those control signals no transmission is received (RF is turned off, for example). That is, as indicated in Fig. 6, for the first two control signals, the UE 10 detects a cell being in a dormant state and conducts a communication quality level measurement for the CRS duration, i.e. on the basis of the incoming CRS symbols.

Now it is assumed that in the second cell identification cycle an operation state change of the eNB 20 into the active state happens. The UE 10 detects at the end of the second cell identification cycle (or the beginning of a third cycle), i.e. after a corresponding duty cycle, on the basis of the cell discovery signal that the eNB 20 is now in the active state. Consequently, the communication quality level measurement is switched to the mode used for the active state, i.e. the UE 10 assumes the CRS is continuously transmitted and thus performs the communication quality level measurement on the basis of a normal CRS pattern.

Fig. 7 shows a flowchart illustrating a processing for conducting a cell identification procedure according to some examples of embodiments of the invention. The method in Fig. 7 is executed, according to some examples of embodiments of the invention, in a communication network control element like the eNB 20.

In step S100, for generating a control signal, in order to provide information for cell identification/discovery, a first type of identification signaling is configured for an active operation state of the cell (i.e. of a communication network control element thereof, like the eNB 20), and a second type of identification signaling is configured for a dormant operation state of the cell (i.e. of the communication network control element). For differentiating the first and second types of identification signaling, at least one of communication settings and parameters thereof is set in a different manner.

In step S110, the cell's operation state, i.e. an active operation state or an inactive operation state, is determined.

In step 120, a decision regarding the further processing is made dependent on the operation state of the cell (i.e. of the eNB 20). When the operation state is the active state, step S130 follows. Otherwise, in case it is determined in step S120 that the operation state is the dormant state, step

S140 follows.

In step S130, a transmission of a control signal for identification of the communication cell according to the first type of identification signaling is caused. Otherwise, in step S140, a transmission of a control signal for identification of the communication cell according to the second type of identification signaling is caused.

According to some examples of embodiments of the invention, the control signal transmitted in step S130 and S140, respectively, comprises a first signal component usable for identifying the communication cell (e.g. a cell ID component) and a second signal component usable for conducting a communication quality level measurement (e.g. a CRS portion). For example, according to some examples of embodiments of the invention, the first and second types of identification signaling are configured on the basis of at least one of a synchronization signal (e.g. PSS/SSS), a reference signal (e.g. CRS), a dedicated cell discovery signal (e.g. PDCH), and a master information block signal (e.g. MIB), wherein the cell ID component is based on them.

Furthermore, according to some examples of embodiments of the invention, when configuring in step S100 the second type of identification signaling (i.e. the one used in the dormant state), a duration for a first signal component usable for identifying the communication cell to an amount is set to being different to a duration of a second signal component usable for conducting a communication quality level measurement, wherein the duration of the second signal component is adjusted to provide a sufficient time for conducting a communication quality level measurement. In other words, according to some examples of embodiments of the invention, the durations of the first and second signal components of the control signal are adjusted correspondingly.

Moreover, according to some examples of embodiments of the invention, for indicating the operation state of the communication network control element (i.e. the active operation state or the dormant operation state), at least one of a configuration, sequence and pattern of a signal component usable for identifying the communication cell is set differently in a control signal according to the second type of identification signaling (in comparison to the corresponding configuration, sequence and pattern of the signal component usable for identifying the communication cell according to the first type of identification signaling). Alternatively or additionally, for indicating the operation state of the communication network control element (i.e. the active operation state or the dormant operation state), a predetermined information element is included in a signal component usable for identifying the communication cell of a control signal according to the second type of identification signaling (in comparison to the corresponding signal component usable for identifying the communication cell according to the first type of identification signaling). In addition, according to some examples of embodiments of the invention, when the operation state of the communication network control element is the dormant state, the control signal is transmitted by using a maximum number of available antenna ports (see e.g. Fig. 3), which is configured, for example, in the second type of identification signaling.

Furthermore, according to some examples of embodiments of the invention, in step S100, when configuring the first and second types of identification signaling, resources used for transmitting a signal component usable for identifying the communication cell (in the dormant state) are coordinated with resources used for legacy channels transmitted in an active operation state of the communication network control element (i.e. the cell identification signal is punctured by legacy channels, for example).

According to some examples of embodiments of the invention, in step S140, i.e. when the communication network control element is in the dormant operation state, the control signal for identification of the communication cell is periodically transmitted according to the second type of identification signaling during a first period of a preset communication cycle, while during the remaining time of the preset communication cycle a transmission of signals is deactivated (see e.g. first and second cell identification cycles in

Fig. 6). Otherwise, in step S130, i.e. when the communication network control element is in the active operation state, the control signal for identification of the communication cell is periodically transmitted according to the first type of identification signaling, while data can be transmitted during the complete communication cycle (see Fig.6).

According to some examples of embodiments of the invention, the eNB 20 provides configuration information assisting the cell identification/discovery procedure. That is, the eNB 20 sends (by broadcasting or dedicated transmission to one or more UEs) an information related to a cell identification cycle in which the control signal (i.e. the cell ID signals) is transmitted. Alternatively or additionally, the eNB 20 sends as the configuration information an offset information indicating a duration offset related to a difference between a duration of a signal component usable for identifying the communication cell (such as PSS/SSS/MI B/PDCH) and a duration of a signal component usable for conducting a communication quality level measurement (such as CRS) in the control signal (i.e. an indication of a duration offset according to the examples of embodiments of the invention described in connection with Figs. 4a/b, 5a/b, for example). The configuration information is transmitted according to some examples of embodiments of the invention with the control signal (in steps S130, S140), or according to some other examples of embodiments of the invention by a separate signaling (not shown in Fig. 7).

Fig. 8 shows a flowchart illustrating a processing for conducting a cell identification procedure according to some examples of embodiments of the invention. The method in Fig. 8 is executed, according to some examples of embodiments of the invention, in a communication element like the UE 10.

In step S200, a control signal for identification of a communication cell is received and processed by the receiving UE 10.

In step S210, an identification or discovery processing for the cell from which the control signal is received is conducted. That is, the UE 10 identifies e.g. the communication network control element of the communication cell sending the control signal by using information delivered by the control signal.

In step S220, an operation state of the communication cell is determined on the basis of information contained in the control signal. That is, the UE 10 determines on the basis of information in the control signal the operation state of the eNB 20 as one of an active operation state and a dormant operation state. For this purpose, a type of identification signaling used for the control signal is evaluated, wherein a first type of the identification signaling is configured for the active state and a second type of the identification signaling is configured for the dormant state, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling. Depending on the result of the determination of the operation state in step

S220, the processing proceeds to step S230 in case of an active operation state of the eNB 20, or to step S240 in case of a dormant operation state of the eNB 20. In step S230, a further processing is conducted with regard to the determination result that the eNB 20 is in the active state. In particular, according to some examples of embodiments of the invention, a communication quality level measurement is executed in accordance with the determined active operation state of the cell (see e.g. right half of Fig. 6). Otherwise, in step S240, a further processing is conducted with regard to the determination result that the eNB 20 is in the dormant state. In particular, according to some examples of embodiments of the invention, a communication quality level measurement is executed in accordance with the determined dormant operation state of the cell (see e.g. left half of Fig.

6).

According to some examples of embodiments of the invention, the control signal received in step S200 comprises a first signal component usable for identifying the communication cell (e.g. a cell ID component) and a second signal component usable for conducting a communication quality level measurement (e.g. a CRS portion).

For example, according to some examples of embodiments of the invention, the first and second types of identification signaling are configured on the basis of at least one of a synchronization signal (e.g. PSS/SSS), a reference signal (e.g. CRS), a dedicated cell discovery signal (e.g. PDCH), and a master information block signal (e.g. MIB), wherein the cell ID component is based on them.

According to some examples of embodiments of the invention, a communication quality level measurement is conducted, when a communication cell is identified on the basis of the control signal, wherein the duration of a signal component usable for identifying the communication cell is different to a duration of a signal component of the control signal being usable for conducting the communication quality level measurement. The communication quality level measurement considers the duration of the signal component of the control signal being usable for conducting the communication quality level measurement. That is, according to some examples of embodiments of the invention, when the operation state of the eNB 20 is determined to be the dormant operation state, the measurement of the communication quality level is conducted in a predetermined time according to a periodic receipt of the control signal for identification of the communication cell (see e.g. first and second cell identification cycles in Fig. 6). Otherwise, when the operation state of the communication network control element is determined to be the active operation state, the measurement of the communication quality level is conducted for each reference signal symbol received (see right half of Fig. 6, for example). As described above, according to some examples of embodiments of the invention, the eNB 20 provides configuration information assisting the cell identification/discovery procedure. That is, according to some examples of embodiments of the invention, the UE 10 receives and processes the configuration information and obtains, for example, an information related to a cell identification cycle in which the control signal (i.e. the cell ID signals) is transmitted. Alternatively or additionally, the UE 10 obtains by the configuration information an offset information indicating a duration offset related to a difference between a duration of a signal component usable for identifying the communication cell (such as PSS/SSS/MI B/PDCH) and a duration of a signal component usable for conducting a communication quality level measurement (such as CRS) in the control signal (i.e. an indication of a duration offset according to the examples of embodiments of the invention described in connection with Figs. 4a/b, 5a/b, for example). The information contained in the configuration information are used, for example, for the cell identification in step S220 or the communication quality level measurement conducted in step S240.

According to some examples of embodiments of the invention, in step S220, the determination of the operation state of the communication cell as one of the active state and the dormant state is based on at least one of a configuration, sequence and pattern of a signal component usable for identifying the communication cell according to the second type of identification signaling which is set differently in a control signal according to the second type of identification signaling (in comparison to the corresponding configuration, sequence and pattern of the signal component usable for identifying the communication cell according to the first type of identification signaling). Alternatively or additionally, the operation state of the communication network control element (i.e. the active operation state or the dormant operation state) is determined on the basis of a predetermined information element included in a signal component usable for identifying the communication cell of a control signal according to the second type of identification signaling (in comparison to the corresponding signal component usable for identifying the communication cell according to the first type of identification signaling). According to some examples of embodiments of the invention, in step S220, a change of the operation state of the communication network control element (i.e. the eNB 20) is detected on the basis of a control signal received, for example, from a cell being already discovered or identified. On the basis of the change detection, a switch of a communication quality level measurement mode is caused. That is, for example, in case the preceding communication quality level measurement mode was set for the dormant state (i.e. step S240 follows step S220), when the operation mode change to the active state is detected, the next communication quality level measurement mode is set for the active state (i.e. step S230 follows step S220).

It is to be noted that according to some examples of embodiments of the invention, step S220 is conducted in predetermined cycles. That is, the detection for a change of the operation state of the communication network control element is conducted periodically in predetermined communication cycles.

Furthermore, according to some examples of embodiments of the invention, in case in step S220 the change of the operation state is detected, a corresponding report is sent by the UE 10 to other network elements. For example, the detected state of a cell is reported to a serving cell (serving eNB) to which the UE 10 is currently connected, e.g. in case the detected cell is a neighboring cell of the serving cell. The reporting is triggered, according to some examples of embodiments of the invention, by at least one of an initial detection of a cell (and hence of a corresponding cell state), when receiving a request from another cell (e.g. instruction from the serving cell), in predetermined intervals, or triggered by other events, such as a change in the detected cell state (e.g. change from dormant to active state, as indicated in Fig. 6). In Fig. 9, a block circuit diagram illustrating a circuitry indicating a configuration of a communication network control element, such as the eNB 20, is shown which is configured to implement the processing for conducting the cell identification mechanism as described in connection with the some examples of embodiments of the invention. That is, a circuitry is shown which comprises at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the eNB 20 to perform functions described below, for example by executing a corresponding algorithm. It is to be noted that the communication network control element or eNB 20 shown in Fig. 9 may comprise several further elements or functions besides those described herein below, which are omitted for the sake of simplicity as they are not essential for understanding the invention. Furthermore, even though reference is made to an eNB, the communication network control element may be also another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a base station or eNB or attached as a separate element to a base station or eNB, or the like. The communication network control element or eNB 20 may comprise a processing function or processor 21, such as a CPU or the like, which executes instructions given by programs or the like related to the cell identification mechanism. The processor 21 may comprise one or more processing portions dedicated to specific processing as described below, or the processing may be run in a single processor. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors or processing portions, such as in one physical processor like a CPU or in several physical entities, for example. Reference signs 22 denote transceiver or input/output (I/O) units connected to the processor 21. The I/O units 22 may be used for communicating with a communication element like UE 10. The I/O units 22 may be a combined unit comprising communication equipment towards several network elements, or may comprise a distributed structure with a plurality of different interfaces for different network elements. Reference sign 23 denotes a memory usable, for example, for storing data and programs to be executed by the processor 21 and/or as a working storage of the processor 21.

The processor 21 is configured to execute processing related to the above described cell identification mechanism. In particular, the processor 21 comprises a sub-portion 211 as a processing portion which is usable for configuring a cell identification signaling. The portion 211 may be configured to perform a processing according to step S100 of Fig. 7, for example. Furthermore, the processor 21 comprises a sub-portion 212 usable as a portion for controlling a control signal transmission. The portion 212 may be configured to perform processing according to steps S120 to S140 of Fig. 6, for example. In addition, the processor 21 comprises a sub-portion 213 usable as a portion for providing configuration information (e.g. cell identification cycle information, offset duration information), i.e. for causing a transmission of configuration information towards UEs, for example.

In Fig. 10, a block circuit diagram illustrating a circuitry indicating a configuration of a communication element, such as the UE 10, is shown which is configured to implement the cell identification mechanism as described in connection with the examples of some embodiment the invention. That is, a circuitry is shown which comprises at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the UE 10 to perform functions described below, for example by executing a corresponding algorithm. It is to be noted that the communication element or UE 10 shown in Fig. 10 may comprise several further elements or functions besides those described herein below, which are omitted for the sake of simplicity as they are not essential for understanding the invention. Furthermore, even though reference is made to an UE, the communication element may be also another terminal device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of an UE or attached as a separate element to a UE, or the like. The communication element or UE 10 may comprise a processing function or processor 11, such as a CPU or the like, which executes instructions given by programs or the like related to the cell identification mechanism. The processor 11 may comprise one or more processing portions dedicated to specific processing as described below, or the processing may be run in a single processor. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors or processing portions, such as in one physical processor like a CPU or in several physical entities, for example. Reference sign 12 denotes transceiver or in put/ out put (I/O) units connected to the processor 11. The I/O units 12 may be used for communicating with a communication network control element like the eNB 20. The I/O units 12 may be a combined unit comprising communication equipment towards several network elements, or may comprise a distributed structure with a plurality of different interfaces for different network elements. Reference sign 13 denotes a memory usable, for example, for storing data and programs to be executed by the processor 11 and/or as a working storage of the processor 11.

The processor 11 is configured to execute processing related to the above described cell identification mechanism. In particular, the processor 11 comprises a sub-portion 111 usable as a processing portion for receiving and processing a control signal. The portion 111 may be configured to perform a processing according to step S200 of Fig. 8, for example. Furthermore, the processor 11 comprises a sub-portion 112 usable as a portion for conducting a cell identification or discovery. The portion 112 may be configured to perform a processing according to step S210 of Fig. 8, for example. In addition, the processor 11 comprises a sub-portion 113 usable as a processing portion for determining a cell operation state. The portion

113 may be configured to perform a processing according to step S220 of Fig. 8, for example. Moreover, the processor 11 comprises a sub-portion

114 usable as a processing portion for conducting a communication quality level measurement. The portion 114 may be configured to perform a processing according to step S230 or step S240 of Fig. 8, for example. In addition, the processor 11 comprises a sub-portion 115 usable as a processing portion for detecting a cell state change (related to step S220 of Fig. 8, for example). In addition, the processor 11 comprises a sub-portion 116 usable as a processing portion for reporting a determined cell state to other network elements. Furthermore, the processor 11 comprises a sub- portion 117 usable as a processing portion for providing configuration information towards UEs.

According to some examples of embodiments of the invention, there is provided an apparatus comprising identification signaling configuration means for configuring a first type of identification signaling for an active operation state of a communication network control element and a second type of identification signaling for a dormant operation state of a communication network control element, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling, and control signal transmission means for causing a transmission of a control signal for identification of a communication cell according to the first type of identification signaling or the second type of identification signaling, depending on an operation state of the communication network control element.

In addition, according to some further examples of embodiments of the invention, there is provided an apparatus comprising control signal receiving and processing means for receiving and processing a control signal for identification of a communication cell, a cell identification means for identifying a communication cell on the basis of the control signal, and cell state determining means for determining an operation state of the communication cell as being one of an active operation state and a dormant operation state on the basis of a type of identification signaling used for the control signal, wherein a first type of the identification signaling is configured for the active operation state of the communication network control element and a second type of the identification signaling is configured for the dormant operation state of the communication network control element, at least one of communication settings and parameters of the first type of the identification signaling being different to the second type of identification signaling. For the purpose of the some embodiments of the present invention as described herein above, it should be noted that

- an access technology via which signaling is transferred to and from a network element may be any technology by means of which a network element or sensor node can access another network element or node (e.g. via a base station or generally an access node). Any present or future technology, such as WLAN (Wireless Local Access Network), WiMAX (Worldwide Interoperability for Microwave Access), LTE, LTE-A, Bluetooth, Infrared, and the like may be used; although the above technologies are mostly wireless access technologies, e.g. in different radio spectra, access technology in the sense of the present invention implies also wired technologies, e.g. IP based access technologies like cable networks or fixed lines but also circuit switched access technologies; access technologies may be distinguishable in at least two categories or access domains such as packet switched and circuit switched, but the existence of more than two access domains does not impede the invention being applied thereto,

- usable communication networks and transmission nodes may be or comprise any device, apparatus, unit or means by which a station, entity or other user equipment may connect to and/or utilize services offered by the access network; such services include, among others, data and/or (audio-) visual communication, data download etc.;

- a user equipment or communication network element may be any device, apparatus, unit or means which is usable as a user communication device and by which a system user or subscriber may experience services from an access network, such as a mobile phone, a wireless mobile terminal, a personal digital assistant PDA, a smart phone, a personal computer (PC), a laptop computer, a desktop computer or a device having a corresponding functionality, such as a modem chipset, a chip, a module etc., which can also be part of a UE or attached as a separate element to a UE, or the like, wherein corresponding devices or terminals may be, for example, an LTE, an LTE-A, a TETRA (Terrestrial Trunked Radio), an UMTS, a GSM/EDGE etc. smart mobile terminal or the like;

- method steps likely to be implemented as software code portions and being run using a processor at a network element or terminal (as examples of devices, apparatuses and/or modules thereof, or as examples of entities including apparatuses and/or modules for it), are software code independent and can be specified using any known or future developed programming language as long as the functionality defined by the method steps is preserved;

- generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the invention in terms of the functionality implemented;

- method steps and/or devices, apparatuses, units or means likely to be implemented as hardware components at a terminal or network element, or any module(s) thereof, are hardware independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as a microprocessor or CPU (Central Processing Unit), 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; in addition, any method steps and/or devices, units or means likely to be implemented as software components may for example be based on any security architecture capable e.g. of authentication, authorization, keying and/or traffic protection;

- devices, apparatuses, units or means can be implemented as individual devices, apparatuses, units or means, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device, apparatus, unit or means is preserved; for example, for executing operations and functions according to examples of embodiments of the invention, one or more processors may be used or shared in the processing, or one or more processing sections or processing portions may be used and shared in the processing, wherein one physical processor or more than one physical processor may be used for implementing one or more processing portions dedicated to specific processing as described,

- an 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 an 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 an apparatus or as an assembly of more than one apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

Furthermore, as used in this application, the terms .device' or .circuitry' refer to all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) combinations of circuits and software (and/or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s)/software (including digital signal processor(s)) , software, and memory(or memories) working together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) circuits, such as a microprocessor (or plural microprocessors) or a portion of a microprocessor (or plural microprocessors), that requires/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. As described above, there is proposed a mechanism for cell identification or discovery. The cell transmits a control signal for identification which is received and processed by a UE. Depending on the operation state of the cell, which is one of an active state and a dormant state, the control signal is configured according to a first type of identification signaling for the active state and a second type of identification signaling for the dormant state, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling. Thus, a dormant cell state or an active cell state can be identified, wherein a communication quality measurement mode is adapted according to the detected cell state.

Although the present invention has been described herein before with reference to particular embodiments thereof, the present invention is not limited thereto and various modifications can be made thereto.

Claims

WHAT I S CLAI MED I S:

1. An apparatus comprising

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to perform

an identification signaling configuration function arranged to configure a first type of identification signaling for an active operation state of a communication network control element and a second type of identification signaling for a dormant operation state of a communication network control element, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling, and

a control signal transmission function configured to cause a transmission of a control signal for identification of a communication cell according to the first type of identification signaling or the second type of identification signaling, depending on an operation state of the communication network control element.

2. The apparatus according to claim 1, wherein the control signal comprises a first signal component usable for identifying the communication cell and a second signal component usable for conducting a communication quality level measurement.

3. The apparatus according to claim 1 or 2, wherein the identification signaling configuration function is further arranged to configure the first and second types of identification signaling on the basis of at least one of a synchronization signal, a reference signal, a dedicated cell discovery signal, and a master information block signal.

4. The apparatus according to any of claims 1 to 3, wherein the identification signaling configuration function is further arranged, when configuring the second type of identification signaling, to set a duration for a first signal component usable for identifying the communication cell to an amount being different to a duration of a second signal component usable for conducting a communication quality level measurement, wherein the duration of the second signal component is adjusted to provide a sufficient time for conducting a communication quality level measurement.

5. The apparatus according to any of claims 1 to 4, wherein the identification signaling configuration function is further arranged, for indicating the operation state of the communication network control element being the active operation state or the dormant operation state, to change at least one of a configuration, sequence and pattern of a signal component usable for identifying the communication cell according to the second type of identification signaling in comparison to the corresponding configuration, sequence and pattern of the signal component usable for identifying the communication cell according to the first type of identification signaling.

6. The apparatus according to any of claims 1 to 5, wherein the identification signaling configuration function is further arranged, for indicating the operation state of the communication network control element being the active operation state or the dormant operation state, to introduce a predetermined information element in a signal component usable for identifying the communication cell according to the second type of identification signaling in comparison to the corresponding signal component usable for identifying the communication cell according to the first type of identification signaling.

7. The apparatus according to any of claims 1 to 6, wherein the control signal transmission function is further configured to cause, when the operation state of the communication network control element is the dormant state, a transmission of the control signal by using a maximum number of available antenna ports, wherein the identification signaling configuration function is further arranged to configure the second type of identification signaling for a transmission using the maximum number of available antenna ports.

8. The apparatus according to any of claims 1 to 7, wherein the identification signaling configuration function is further arranged, when configuring the first and second types of identification signaling, to coordinate resources used for transmitting a signal component usable for identifying the communication cell with regard to resources used for legacy channels transmitted in an active operation state of the communication network control element.

9. The apparatus according to any of claims 1 to 9, wherein the control signal transmission function is further configured,

when the communication network control element is in the dormant operation state, to cause a periodic transmission of the control signal for identification of the communication cell according to the second type of identification signaling during a first period of a preset communication cycle and to cause a deactivation of a transmission of signals during the remaining time of the preset communication cycle, and

when the communication network control element is in the active operation state, to cause a periodic transmission of the control signal for identification of the communication cell according to the first type of identification signaling and a transmission of data during a complete communication cycle.

10. The apparatus according to any of claims 1 to 9, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to perform

a configuration information providing function configured to provide configuration information indicating at least one of

a cell identification cycle in which the control signal is transmitted, and

an offset information indicating a duration offset related to a difference between a duration of a signal component usable for identifying the communication cell and a duration of a signal component usable for conducting a communication quality level measurement in the control signal.

11. The apparatus according to any of claims 1 to 10, wherein the apparatus is included in a communication network control element comprising at least one of a base station of a cellular network, an evolved node B of a Long Term Evolution or Long Term Evolution Advanced communication network, and an access node, wherein the control signal is transmitted towards a communication element comprising at least one of a terminal device or user equipment communicating with the communication network control element.

12. A method comprising

configuring a first type of identification signaling for an active operation state of a communication network control element and a second type of identification signaling for a dormant operation state of a communication network control element, wherein at least one of communication settings and parameters of the first type of the identification signaling is different to the second type of identification signaling, and

causing a transmission of a control signal for identification of a communication cell according to the first type of identification signaling or the second type of identification signaling, depending on an operation state of the communication network control element.

13. The method according to claim 12, wherein the control signal comprises a first signal component usable for identifying the communication cell and a second signal component usable for conducting a communication quality level measurement.

14. The method according to claim 12 or 13, further comprising configuring the first and second types of identification signaling on the basis of at least one of a synchronization signal, a reference signal, a dedicated cell discovery signal, and a master information block signal.

15. The method according to any of claims 12 to 14, further comprising, when configuring the second type of identification signaling, setting a duration for a first signal component usable for identifying the communication cell to an amount being different to a duration of a second signal component usable for conducting a communication quality level measurement, wherein the duration of the second signal component is adjusted to provide a sufficient time for conducting a communication quality level measurement.

16. The method according to any of claims 12 to 16, further comprising, for indicating the operation state of the communication network control element being the active operation state or the dormant operation state, changing at least one of a configuration, sequence and pattern of a signal component usable for identifying the communication cell according to the second type of identification signaling in comparison to the corresponding configuration, sequence and pattern of the signal component usable for identifying the communication cell according to the first type of identification signaling.

17. The method according to any of claims 12 to 17, further comprising, for indicating the operation state of the communication network control element being the active operation state or the dormant operation state, introducing a predetermined information element in a signal component usable for identifying the communication cell according to the second type of identification signaling in comparison to the corresponding signal component usable for identifying the communication cell according to the first type of identification signaling.

18. The method according to any of claims 12 to 17, further comprising causing, when the operation state of the communication network control element is the dormant state, a transmission of the control signal by using a maximum number of available antenna ports, wherein the second type of identification signaling is configured for a transmission using the maximum number of available antenna ports.

19. The method according to any of claims 12 to 18, further comprising, when configuring the first and second types of identification signaling, coordinating resources used for transmitting a signal component usable for identifying the communication cell with regard to resources used for legacy channels transmitted in an active operation state of the communication network control element.

20. The method according to any of claims 12 to 19, further comprising: when the communication network control element is in the dormant operation state, causing a periodic transmission of the control signal for identification of the communication cell according to the second type of identification signaling during a first period of a preset communication cycle and to cause a deactivation of a transmission of signals during the remaining time of the preset communication cycle, and

when the communication network control element is in the active operation state, causing a periodic transmission of the control signal for identification of the communication cell according to the first type of identification signaling and a transmission of data during a complete communication cycle.

21. The method according to any of claims 12 to 20, further comprising providing configuration information indicating at least one of

a cell identification cycle in which the control signal is transmitted, and

22. The method according to any of claims 12 to 21, wherein the method is implemented in a communication network control element comprising at least one of a base station of a cellular network, an evolved node B of a Long Term Evolution or Long Term Evolution Advanced communication network, and an access node, wherein the control signal is transmitted towards a communication element comprising at least one of a terminal device or user equipment communicating with the communication network control element.

23. An apparatus comprising

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to perform a control signal receiving and processing function configured to receive and process a control signal for identification of a communication cell,

a cell identification function configured to identify a communication cell on the basis of the control signal, and

a cell state determining function configured to determine an operation state of the communication cell as being one of an active operation state and a dormant operation state on the basis of a type of identification signaling used for the control signal, wherein a first type of the identification signaling is configured for the active operation state of the communication network control element and a second type of the identification signaling is configured for the dormant operation state of the communication network control element, at least one of communication settings and parameters of the first type of the identification signaling being different to the second type of identification signaling.

24. The apparatus according to claim 23, wherein the control signal comprises a first signal component usable for identifying the communication cell and a second signal component usable for conducting a communication quality level measurement.

25. The apparatus according to claim 23 or 24, wherein the first and second types of identification signaling are based on at least one of a synchronization signal, a reference signal, a dedicated cell discovery signal, and a master information block signal.

26. The apparatus according to any of claims 23 to 25, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to perform

a communication quality level measurement function configured to conduct a measurement of a communication quality level with regard to the communication cell identified by the control signal by using a signal component of the control signal being usable for conducting the communication quality level measurement.

27. The apparatus according to claim 26, wherein the communication quality level measurement function is further configured to conduct the measurement of the communication quality level when the cell identification function has identified a communication cell on the basis of the control signal,

wherein a duration of a first signal component of the control signal being usable for identifying the communication cell is different to a duration of a second signal component of the control signal being usable for conducting the communication quality level measurement.

28. The apparatus according to any of claims 26 and 27, wherein the communication quality level measurement function is further configured, when the operation state of the communication network control element is determined to be the dormant operation state, to conduct the measurement of the communication quality level in a predetermined time according to a periodic receipt of the control signal for identification of the communication cell, and

when the operation state of the communication network control element is determined to be the active operation state, to conduct the measurement of the communication quality level for each reference signal symbol received.

29. The apparatus according to any of claims 23 to 28, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to perform

a configuration information receiving and processing function configured to receive and process configuration information indicating at least one of

a cell identification cycle in which the control signal is received, and

an offset information indicating a duration offset related to a difference between a duration of a signal component usable for identifying the communication cell and a duration of a signal component usable for conducting a communication quality level measurement in the control signal, wherein the offset information is usable for conducting a measurement of a communication level quality level.

30. The apparatus according to any of claims 23 to 29, wherein the cell state determining function is further configured to determine the operation state of the communication cell as being one of the active operation state and the dormant operation state on the basis of at least one of a configuration, sequence and pattern of a signal component usable for identifying the communication cell according to the second type of identification signaling which is different in comparison to the corresponding configuration, sequence and pattern of the signal component usable for identifying the communication cell according to the first type of identification signaling.

31. The apparatus according to any of claims 23 to 30, wherein the cell state determining function is further configured to determine the operation state of the communication cell as being one of the active operation state and the dormant operation state on the basis of a predetermined information element introduced in a signal component usable for identifying the communication cell according to the second type of identification signaling, in comparison to the corresponding signal component usable for identifying the communication cell according to the first type of identification signaling.

32. The apparatus according to any of claims 23 to 31, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to perform

a cell state change detecting function configured to detect, on the basis of the control signal, a change of the operation state of the communication network control element, wherein the cell state change detecting function is further configured to cause a switch of a communication quality level measurement mode according to the changed operation state of the communication network control element.

33. The apparatus according to any of claims 23 32, wherein the cell state change detecting function is further configured to detect for a change of the operation state of the communication network control element periodically in predetermined communication cycles.

34. The apparatus according to any of claims 23 to 33, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to perform

a reporting function configured to cause a report of a determined operation state of the communication network control element.

35. The apparatus according to any of claims 23 to 34, wherein the apparatus is included in a communication element comprising at least one of a terminal device, user equipment or mobile phone communicating with the communication network control element.

36. The apparatus according to any of claims 23 to 35, wherein the communication network control element comprises at least one of a base station of a cellular network, an evolved node B of a Long Term Evolution or Long Term Evolution Advanced communication network, and an access node, wherein the control signal is received from the communication network control element.

37. A method comprising

receiving and processing a control signal for identification of a communication cell,

identifying a communication cell on the basis of the control signal, and

determining an operation state of the communication cell as being one of an active operation state and a dormant operation state on the basis of a type of identification signaling used for the control signal, wherein a first type of the identification signaling is configured for the active operation state of the communication network control element and a second type of the identification signaling is configured for the dormant operation state of the communication network control element, at least one of communication settings and parameters of the first type of the identification signaling being different to the second type of identification signaling.

38. The method according to claim 37, wherein the control signal comprises a first signal component usable for identifying the communication cell and a second signal component usable for conducting a communication quality level measurement.

39. The method according to claim 37 or 38, wherein the first and second types of identification signaling are based on at least one of a synchronization signal, a reference signal, a dedicated cell discovery signal, and a master information block signal.

40. The method according to any of claims 37 to 39, further comprising conducting a measurement of a communication quality level with regard to the communication cell identified by the control signal by using a signal component of the control signal being usable for conducting the communication quality level measurement.

41. The method according to claim 40, wherein the measurement of the communication quality level is conducted when a communication cell is identified on the basis of the control signal,

42. The method according to any of claims 40 and 41 , further comprising when the operation state of the communication network control element is determined to be the dormant operation state, conducting the measurement of the communication quality level in a predetermined time according to a periodic receipt of the control signal for identification of the communication cell, and

when the operation state of the communication network control element is determined to be the active operation state, conducting the measurement of the communication quality level for each reference signal symbol received.

43. The method according to any of claims 37 to 42, further comprising receiving and processing configuration information indicating at least one of

a cell identification cycle in which the control signal is received, and

44. The method according to any of claims 37 to 43, further comprising determining the operation state of the communication cell as being one of the active operation state and the dormant operation state on the basis of at least one of a configuration, sequence and pattern of a signal component usable for identifying the communication cell according to the second type of identification signaling which is different in comparison to the corresponding configuration, sequence and pattern of the signal component usable for identifying the communication cell according to the first type of identification signaling.

45. The method according to any of claims 37 to 44, further comprising determining the operation state of the communication cell as being one of the active operation state and the dormant operation state on the basis of a predetermined information element introduced in a signal component usable for identifying the communication cell according to the second type of identification signaling, in comparison to the corresponding signal component usable for identifying the communication cell according to the first type of identification signaling.

46. The method according to any of claims 37 to 45, further comprising

detecting, on the basis of the control signal, a change of the operation state of the communication network control element, and causing a switch of a communication quality level measurement mode according to the changed operation state of the communication network control element.

47. The method according to claim 46, wherein the detection for a change of the operation state of the communication network control element is conducted periodically in predetermined communication cycles.

48. The method according to any of claims 37 to 47, further comprising reporting the detection of a determined operation state of the communication network control element.

49. The method according to any of claims 37 to 48, wherein the method is implemented in a communication element comprising at least one of a terminal device, user equipment or mobile phone communicating with the communication network control element.

50. The method according to any of claims 37 to 49,, wherein the communication network control element comprises at least one of a base station of a cellular network, an evolved node B of a Long Term Evolution or Long Term Evolution Advanced communication network, and an access node, wherein the control signal is received from the communication network control element.

51. A computer program product for a computer, comprising software code portions for performing the steps of any of claims 12 to 22, or of claims 37 to 50, when said product is run on the computer.

52. The computer program product according to claim 51, further comprising a computer-readable medium on which said software code portions are stored.

53. The computer program product according to claim 51, wherein 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.