WO2014127801A1

WO2014127801A1 - Switching over from a sectorization pattern to another

Info

Publication number: WO2014127801A1
Application number: PCT/EP2013/053252
Authority: WO
Inventors: Jarmo Tapani MÄKINEN; Jacek KUTROWSKI
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2013-02-19
Filing date: 2013-02-19
Publication date: 2014-08-28

Abstract

To provide automatic switching over from a sectorization pattern to another sectorization pattern, at least one value indicating a load in a cell is compared with a threshold; and based at least on the comparison result, it is determined, whether or not to switch over from the sectorization pattern to the other sectorization pattern.

Description

SWITCHING OVER FROM A SECTORIZATION PATTERN TO ANOTHER

FIELD

The present invention relates to a cell site, and especially to a cell site supporting splitting of a cell. BACKGROUND ART

The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with dis-closures not known to the relevant art prior to the present invention but provided by the invention. Some such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context .

In recent years, the phenomenal growth of mobile

Internet services and proliferation of smart phones and tablets has increased a demand for mobile broadband

services. Development of antenna technology from an omnidirectional antenna to antenna solutions providing horizontal splitting of a cell to cell sectors, or even horizontal and vertical splitting of a cell to cell sectors has increased coverage and a capacity of a radio network. Splitting a cell to sectors is called sectorization. Commonly used one-level sectorization pattern, or classic sectorization pattern, is to have a site with 3 or 6 horizontal sectors, often referred as 3x1, 6x1 sectorization pattern, and corresponding two- level sectorization pattern is obtained by further splitting the horizontal sectors to two vertical sectors, the

sectorization pattern being referred to 3x2, 6x2

sectorization pattern, respectively. If there are very many users distributed rather evenly, the higher order

sectorization pattern should increase the capacity, but if there are a small amount of users, due to the increased level of inter-cell interference, the higher order sectorization pattern may decrease the capacity and/or cause deterioration of some other radio network guality parameters. SUMMARY

A general aspect of the invention provides an automatic switching over between two sectorization patterns . Various aspects of the invention comprise methods, an apparatus and a computer program product as defined in the independent claims. Further embodiments of the invention are disclosed in the dependent claims .

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, embodiments will be described in greater detail with reference to accompanying drawings, in which

Figure 1 depicts a cell site arrangement;

Figures 2, 3 and 4 are flow charts illustrating exemplary functionalities; and

Figure 5 is a schematic block diagram of the exemplary apparatus .

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The following embodiments are exemplary. Although the specification may refer to "an", "one", or "some"

embodiment ( s ) in several locations, this does not necessarily mean that each such reference is to the same embodiment ( s ) , or that the feature only applies to a single embodiment.

Single features of different embodiments may also be combined to provide other embodiments.

The present invention is applicable to any base station, or corresponding eguipment, that provides one or more cells or cell sectors for wireless communication between a user eguipment and a network/system and that supports at least two different sectorization patterns. The base station may be for a wireless system or for a system utilizing both fixed connections and wireless connections, and the base station may be configured to support one or more wireless access. Examples of such systems/networks include LTE/SAE (Long Term Evolution/System Architecture Evolution) radio system,

Worldwide Interoperability for Microwave Access (WiMAX) , Global System for Mobile communications (GSM, 2G) , GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W- CDMA), high-speed packet access (HSPA), advanced LTE (LTE-A) , and/or beyond LTE-A. The specifications of different systems and networks, especially in wireless communication, develop rapidly. Such development may reguire extra changes to an embodiment. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment.

Figure 1 illustrates a cellular arrangement in an exemplary system 100, the cellular arrangement showing a base station 200 providing a cell that is split to sectors: horizontally to three sectors 210, 220, 230 and then two of them further vertically to sectors 211, 221. In other words, a lower order sectorization pattern, which in the examples herein is the classic sectorization pattern 3x1, is used to obtain sector 230, and the higher order sectorization pattern is used to obtain a sector comprising an outer sector 210 and an inner sector 211 and a sector comprising the outer sector 220 and the inner sector 221. One can say that a higher order sectorization pattern further splits at least one sector obtained by a lower order sectorization pattern. For example, if only two sectorization patterns are used and the lower order sectorization pattern is 3x1, a higher order

sectorization pattern may be one of the following 6x1, 3x2, 3x3, 6x2, 6x3, etc. Another example includes that if more than two sectorization patterns are used, and the lower order sectorization pattern 3x1 is switched over to "next" order sectorization pattern 3x2, a higher order sectorization pattern for the next may be selected amongst the following patterns: 3x3, 6x2, 6x3, etc.

The base station may be an evolved Node B (eNB) based on an active antenna system, for example. It should be appreciated that the base station may be configured to split a cell to any number of horizontal sectors, each of which may then undergo a vertical sectorization. The vertical sectorization may be performed for each horizontal sector separately (i.e. independently on other horizontal sectors), or horizontal sectors may form a cluster and horizontal sectors belonging to the same cluster will undergo the vertical sectorization together, or all horizontal sectors will undergo the vertical sectorization together, and vice versa when vertical

sectorization is switched off. A sector corresponds to a cell, and hence the outer sector may correspond to a macro cell and the inner sector to a micro cell.

To maximise the site and radio network capacity, a mechanism for automatic switching over between different sectorization patterns is introduced, and described in more detail with Figures 2 and 3 with the classic sectorization pattern

(vertical sectorization off) and the two-level sectorization pattern (vertical sectorization on) , without restricting the invention to such a solution. It should be appreciated that switching over automatically from one sectorization pattern to another sectorization pattern may be performed for any number of sectorization patterns and between any type of sectorization patterns. For example, the a lower order classic sectorization pattern 3x1 may be automatically switched over to a higher order sectorization pattern 6x1, which may switched over to a higher order sectorization pattern 6x2, and vice versa. Below it is assumed that configurable (programmable), pre-set threshold levels are used, as well as a configurable (programmable), pre-set count value for indicating a time that has passed and a configurable (programmable), pre-set scaling factor. However, it bears no significance to the invention the way how the levels and/or times, or corresponding values/information is provided; any other known or future way to provide

corresponding values may be used.

Figure 2 illustrates one example on how measurement reports may be used for determining whether or not to switched over from one sectorization pattern to another. In the example the vertical sectorization is switched on or off, or vice versa, without limiting the solution to such a switching over. In other words, Figure 2 illustrates an example in which the number of sectors in the vertical plane is different for each horizontal sector, based on the present load in the

particular horizontal sector. Further, in the example it is assumed that an antenna beam tilt is adjusted. However, it should be appreciated that in other implementations both the antenna beam tilt and an antenna beam width is adjusted, or only the antenna beam width is adjusted, or neither of them is adjusted. Further, some other adjustment may take place.

When the vertical sectorization is switched on in step 201, i.e. the classic sectorization pattern is switched over to the higher order sectorization pattern, the transmit power for the inner sector is ramped up and the transmit power for the outer sector is reduced in step 202 by 3dB, for example. It should be appreciated that if the total transmit power is limited, the transmit power for the outer sector may be reduced more or ramped down, preferably gradually, so that there will be time to handover a user eguipment (UE) to the inner sector if a signal to interference plus noise ratio (SINR), for example, drops to be too low. It is also possible not to reduce the transmit power for the outer sector.

Further, the antenna beam tilt that previously provided coverage to the "whole" sector is adjusted in step 204 to provide optimized coverage to the outer sector. In other words, the antenna beam tilt is adapted to the changed situation. Now the higher order sectorization pattern is in use .

When a measurement report comprising separate

reports/measurement results for uplink (UL) load in the inner sector, downlink (DL) load in the inner sector, uplink (UL) load in the outer sector and downlink (DL) load in the outer sector is received in step 204, it is checked in step 205, whether or not both the uplink load in the inner sector (i- UL) is below a first threshold level thl and the downlink load in the inner sector (i-DL) is below a second threshold level th2, both threshold levels being a low load level that in a way indicates a level above which the higher order sectorization pattern is expected to provide the capacity gain. It should be appreciated that the second threshold level for the downlink load may be the same as the first threshold level for the uplink load, or the levels may be different . If the uplink load in the inner sector is below the first threshold level and the downlink load in the inner sector is below the second threshold level (step 205), it is checked in step 206, whether or not the situation was the same in x previous reports, "x" is a count value ensuring that

temporary decreases in the uplink or in the downlink load in the inner sector are filtered away, the time after which the decrease is determined not to be temporary being defined by the count value (this is based on an assumption that

measurement reports are received in short intervals) . It should be appreciated that a timer, for example, may be used instead of the count value x. Further, there may be different reguirements for uplink and downlink.

If the decrease in the uplink load and in the downlink load in the inner sector is not a temporary one, it is checked, in step 207, whether or not both the uplink load in the inner sector and the downlink load in the inner sector are zero and have been zero in the x previous reports, i.e. whether or not If there has been no traffic in the inner cell for a certain period., If there has been some traffic (with load under the threshold levels) during the period, it is checked in step 208, using the latest received uplink load in the outer sector (o-UL) and the latest received downlink load in the outer sector (o-DL), whether or not both the uplink load in the outer sector is below a third threshold level th3 and the downlink load in the outer sector is below a fourth threshold level th4 , the third threshold level indicating a level above which the uplink load is excessive in the outer cell and the fourth threshold level indicating a level above which the downlink load is excessive . It should be appreciated that the fourth threshold level for the downlink load may be the same as the third threshold level for the uplink load, or the levels may be different.

If the downlink load in the outer sector is above the fourth threshold level (step 208), and/or the uplink load in the outer sector is above the third threshold level (step 208), the vertical sectorization is maintained in use, and the process proceeds to step 204 to receive measurement reports.

If the uplink load in the inner sector is not below the first threshold level and/or the downlink load in the inner sector is not below the second threshold level (step 205), the process proceeds to step 204 to receive measurement reports.

If the situation was not the same in x previous reports (step 206), i.e. the decrease is still considered as temporary, the process proceeds to step 204 to receive measurement reports.

If there has been no load in the inner cell for the certain period (step 207), or if both the uplink load in the outer sector and the downlink load in the outer sector (o-DL) is below the respective threshold level th3, th4 (step 208), the vertical sectorization is switched off in step 209, i.e. the higher order sectorization pattern is switched over to the classic sectorization pattern. Therefore the transmit power for the inner sector is ramped down and the transmit power for the outer sector is ramped up in step 210. The ramping is performed preferably gradually, for example by 3 dB, so that there will be time to handover each user eguipment (UE) from the inner sector before the inner sector is "vanished".

Alternatively, a network initiated handover of user

eguipments in the inner sector may be performed before the ramping down of the inner sector starts. Further, the antenna beam tilt that previously provided the outer sector is readjusted in step 211 to provide the whole sector. In other words, the antenna beam tilt is adapted to the changed situation. Now the classic sectorization pattern is in use.

When a measurement report comprising separate reports/measurement results for uplink (UL) and downlink (DL) load caused by user eguipments locating close to the base station, and for uplink (UL) and downlink (DL) load caused by the user eguipments locating not close to the base station is received in step 212, it is checked in step 213, whether or not both the total uplink load in the cell (t-UL) is above a fifth threshold level and the uplink load caused by user eguipments locating close to the base station (c-UL) is above a result obtained by multiplying the uplink load caused by user eguipments not locating close to the base station (d-UL) by a scaling factor k. The fifth threshold level is an uplink high load limit..

If the uplink load is not above the fifth threshold level and/or the "close" uplink load is not above the result (step 213), a similar check is performed in step 214 to downlink load, In other words, it is checked in step 214, whether or not both the total downlink load in the cell (t-DL) is above a sixth threshold level and the downlink load caused by user eguipments locating close to the base station (c-DL) is above a result obtained by multiplying the downlink load caused by user eguipments not locating close to the base station (d-DL) by the scaling factor k. The sixth threshold level is a downlink high load limit. It should be appreciated that the sixth threshold level for the downlink load may be the same as the fifth threshold level for the uplink load, or the levels may be different. If the total downlink load is not above the sixth threshold level (step 214) and/or the "close" downlink load is not above the result, the vertical sectorization is maintained switched off, and the process proceeds to step 218 to receive measurement reports . If both the total uplink load is above the fifth threshold level and the "close" uplink load is above the result (step

213) , it is checked in step 215, whether or not the situation was the same in x previous reports to filter temporary load increases away. If the increase is not a temporary (step 215) the process proceeds to step 201 to switch on the vertical sectorization, i.e. the classic sectorization pattern is switched over to the higher order sectorization pattern. If the situation was not the same in x previous reports (step 215), i.e. the decrease is still considered as temporary, the process proceeds to step 212 to receive measurement reports.

If both the total downlink load is above the sixth threshold level and the "close" downlink load is above the result (step

214) , it is checked in step 216, whether or not the situation was the same in x previous reports to filter temporary load increases away. If the increase is not a temporary one, the process proceeds to step 201 to switch on the vertical sectorization, i.e. the classic sectorization pattern is switched over to the higher order sectorization pattern. If the situation was not the same in x previous reports (step 216), i.e. the decrease is still considered as temporary, the process proceeds to step 212 to receive measurement reports.

Although in the above the same count value x was used, it should be appreciated that different count values, and hence different time periods, may be deployed in step 206 and/or in step 207 and/or in step 215 and/or in step 216.

In a further implementation temporary changes are not filtered away (steps 206, 215 and 216 are omitted, and in step 207 only the latest results are taken into account) .

An algorithm illustrating a similar functionality as

described above with Figure 2 may be expressed as follows, VS stands for vertical sectorization:

IF VS is off (only outer cell is operational) • IF the total DL load in the cell is more than <DL high load limit> AND

• IF A_DL > kx B_DL (kx = scaling factor), switch on VS

• IF the total UL load in the cell is more than <UL high load limit> AND

• IF A_UL > k_t B_UL (k_t = scaling factor), switch on VS (A refers to load in UEs close to BS, B refers to load in other UEs)

IF VS is on (both cells are operational) AND load in outer cell is not ecessive

• IF the DL load in inner cell is less than <DL low load limit> over a predefined time AND

• IF the UL load in inner cell is less than <UL low load limit> over a predefined time , switch off VS

Instead of ki B_DL and k i B_DL a fixed value may used, in which implementation there is no need to report loads caused by user equipments not close to the base station. In another implementation of the above algorithm B refers to the total traffic of the cell.

Another example for additional rules:

If VS switched off, and if "not close BS load"=0 (no load) and "close BS load">th5 or >th6, stay. If ["close BS

load">th5 or >th6] AND ["not close BS load">0] , switch VS on.

Still another example for a decision algorithm is following:

When vertical sectorization is on, and the load (both in downlink and uplink) in the inner cell is constant ly below a threshold value and the load in the outer cell (neither downlink nor uplink) is not excessive, the vertical

sectorizat ion will be switched off.

When vertical sectorization is off, and the estimated load (in downlink or uplink) close to the base station exceeds a threshold value (separate for DL and UL) , the vertical sectorization will be switched on.

Figure 3 is a flow chart illustrating an enhancement to the functionality described above with Figure 2. The steps 301- 316 correspond to steps 201-216, and are not repeated in vain therein. To provide more flexibility to switch vertical configuration off in case there is no load, or almost no load in the outer sector although there is load the inner sector. In other words, in the example of Figure 3, if the uplink load in the inner sector is not below the first threshold level and/or the downlink load in the inner sector is not below the second threshold level (step 305), the process proceeds to step 317 to check whether or not the uplink load in the outer sector is below a seventh threshold level and/or the downlink load in the outer sector is below the eighth threshold level, both threshold levels being in the example "near zero" levels having a very small value, but different than zero, for example 0.00001. It should be appreciated that the seventh threshold level for the downlink load may be the same as the eight threshold level for the uplink load, or the levels may be different.

If there is no load or almost no load (step 317), i.e. the uplink load in the outer sector is below the seventh

threshold level and the downlink load in the outer sector is below the eight threshold level, it is checked in step 318, whether or not the situation was the same in y previous reports, y being a count value also ensuring that temporary decreases in the uplink or in the downlink load in the outer sector are filtered away but having a different value, preferably a bigger one, than the count value x. It should be appreciated that the count values used may be the same. If the decrease in the uplink load and in the downlink load in the outer sector is not a temporary one (step 318), the process proceeds to step 309 to switch off the vertical sectorization. If the situation was not the same in y previous reports (step 318), i.e. the "almost no load or no load" is still

considered as temporary, the process proceeds to step 304 to receive measurement reports .

If the uplink load in the outer sector is above the seventh threshold level and/or the downlink load in the outer sector is above the eight threshold level, the process proceeds to step 304 to receive measurement reports.

Alternatively to implementing only steps 317 and 318, a process similar to the process described with steps 305 to 308 (described in detail with steps 205 to 208) may be implemented to the outer sector.

Figure 4 is a flow chart illustrating one example on how measurement reports having loads classified to two different areas (inner sector/outer sector and close/not close) are obtained. It should be appreciated that the same principles are usable in implementations in which loads are classified to more than two different areas. Further, it is apparent to one skilled in the art how to implement the procedure when deciding between different sectorization patterns reguire different number of areas per a sectorization pattern, like inner sector/outer sector when vertical sectorization is on and close/middle/remote when vertical sectorization is off.

If the vertical sectorization is on (step 401), downlink traffic in the inner sector is measured in step 402 to determine the corresponding load, uplink traffic in the inner sector is measured in step 403 to determine the corresponding load, downlink traffic in the outer sector is measured in step 404 to determine the corresponding load, and uplink traffic in the outer sector is measured in step 405 to determine the corresponding load. It should be appreciated that instead of using traffic, load may be derived from utilisation of freguency spectrum and SNIR, for example.

The measurement of the downlink/uplink traffic in a sector may be based on any capacity counter/indicator, or any combination of them. Examples of the capacity counters/indicators include the number of occupied

transmission time intervals (TTIs) and "average number of user eguipments with buffered data in downlink/uplink", "(number of downlink occupied TTIs )/ (average number of user eguipments with buffered data in downlink)", and "(number of uplink occupied TTIs )/ (average number of user eguipments with buffered data in uplink)".

The above measurements are collected to a measurement report comprising separate reports/measurement results for uplink (UL) load in the inner sector, downlink (DL) load in the inner sector, uplink (UL) load in the outer sector and downlink (DL) load in the outer sector, and at certain short intervals a report is provided (step 406) to processes needing it, like the process described above with Figure 2. Hence, the decision whether or not to switch over a

sectorization pattern is made in almost real-time and reflects the real-time situation.

Steps 402 to 406 are repeated as long as the vertical sectorization is on, and steps 407 to 414 as long as the vertical sectorization is off.

When the vertical sectorization is switched off (step 401), the distribution of user eguipments within a sector needs to be taken into account somehow to measure traffic with user eguipments near the base station and traffic with user eguipments more away from the base station separately. For that a maximum distance which is deemed to be close to the base station may be a configurable (programmable), pre-set parameter. Therefore a served user eguipment, i.e. a user eguipment in the sector, is taken in step 407 to be

processed. It is determined in step 408 how far away from the base station the user eguipment is while the uplink and downlink traffic of the user eguipment is being measured (step 409) . For example, a timing advance corresponding to the length of time a signal takes to reach the base station from the user eguipment may be used for indicating a distance between the base station and the user equipment without restricting the example to such an implementation. Any other corresponding mechanism may be used. For example, information about location of a user equipment may be obtained from special Localisation Services platforms providing real time, or quasi-real time, location information. The traffic measurement may be performed by means of any capacity counter/indicator, or any combination of them, like the number of transmission time interval (TTIs) occupied by the user equipment and whether or not the user equipment is a user equipment with buffered data.

If the user equipment is determined not to be close to the base station (step 410), the traffic measurements are added in step 411 to corresponding traffic measurements of other user equipments that are determined not to be close to the base station. Then the process proceeds to step 413 to check, whether or not measurements are performed to all served user equipments. If not, the process proceeds to step 407 to take a served user equipment to be processed.

If the user equipment is determined to be close to the base station (step 410), the traffic measurements are added in step 412 to corresponding traffic measurements of other user equipments that are determined to be close to the base station. Then the process proceeds to step 413 to check, whether or not measurements are performed to all served user equipments .

To determine whether a user equipment is close or not close, the timing advance may be compared to a pre-set timing advance limit, for example.

During the adding in step 412 or 413, the measurement of the close/not close traffic in a sector may be performed based on any capacity counter/indicator, or any combination of them. Examples of the capacity counters/indicators include the number of transmission time intervals (TTIs) occupied by these user equipments and "average number of these user equipments with buffered data in downlink/uplink", "(number of downlink TTIs occupied by these user equipments )/( average number of these user equipments with buffered data in downlink)", and "(number of uplink TTIs occupied by these user equipments)/ (average number of these user equipments with buffered data in uplink)".

The above measurements addings are collected to a measurement report comprising separate reports/measurement results for uplink (UL) load caused by user equipments close to the base station, downlink (DL) load caused by user equipments close to the base station, uplink (UL) load caused by user

equipments not close to the base station and downlink (DL) load caused by user equipments not close to the base station, and at certain short intervals, after all served user equipments are processed (step 413) a report is provided (step 414) to processes needing it, like the process

described above with Figure 2.

In other examples relating to examples in Figures 2, 3 and 4, uplink and downlink loads are not treated separately when the vertical sectorization is switched off, and/or uplink and downlink loads in the inner sector are not treated separately when the vertical sectorization is switched on, and/or uplink and downlink loads in the outer sector are not treated separately when the vertical sectorization is switched on. Although in the above the examples are based on sector- specific procedures it should be appreciated that the procedures may be performed cell-specifically or for two or more sectors at a time.

Figure 5 is a simplified block diagram illustrating some units for an apparatus 500 configured to function as a base station, or as a corresponding apparatus providing a cell site. In the illustrated example the apparatus comprises a sectorization switching unit 501 for the functionality described above with Figure 2 or 3, and a measurement unit 502 for the functionality described above with Figure 4. In other words, the sectorization switching unit 501 is configured to automatically decide on whether or not to switch over from a sectorization pattern currently in use to another sectorization pattern based on the information received from the measurement unit 502, and the measurement unit 502 is configured to provide measurement reports whose content depend on the used sectorization pattern and provide information needed by the sectorization switching unit 501.

In other words, the apparatus 500 configured to provide a cell for wireless access, is a computing device that may be any apparatus or device or eguipment or network node configured to perform one or more of corresponding apparatus functionalities described with an

embodiment/example/implementation, and it may be configured to perform functionalities from different

embodiments/examples/implementations. The sectorization switching unit 501 and the measurement unit 502 described with the apparatus may be separate units, even locate in another physical apparatus, the physical apparatuses forming one logical apparatus providing the base station

functionality, or integrated to each other and/or to another unit in the same apparatus .

More precisely, the sectorization switching unit 501 and/or the measurement unit 502 may be software and/or software- hardware and/or firmware component (recorded indelibly on a medium such as read-only-memory or embodied in hard-wired computer circuitry) . The technigues described herein may be implemented by various means so that an apparatus

implementing one or more functions of a corresponding apparatus/entity described with an

embodiment/example/implementation comprises not only prior art means, but also means for implementing the one or more functions of a corresponding procedure described with an embodiment/example/implementation and it may comprise separate means for each separate function, or means may be configured to perform two or more functions . For a firmware or software, implementation can be through modules (e.g., procedures, functions, and so on) that perform the functions described herein. Software codes may be stored in any suitable, processor/computer-readable data storage medium(s) or memory unit(s) or article (s) of manufacture and executed by one or more processors/computers.

An apparatus implementing functionality or some functionality according to an embodiment/example/implementation may generally include a processor, controller, control unit, micro-controller, or the like connected to a memory and to various interfaces of the apparatus. Generally the processor is a central processing unit, but the processor may be an additional operation processor. The sectorization switching unit 501 and/or the measurement unit 502 may be configured as a computer or a processor, or a microprocessor, such as a single-chip computer element, or as a chipset, including at least a memory for providing storage area used for arithmetic operation and an operation processor for executing the arithmetic operation. The sectorization switching unit 501 and/or the measurement unit 502 may comprise one or more computer processors, application-specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field-programmable gate arrays (FPGA) , and/or other hardware components that have been programmed in such a way to carry out one or more functions of one or more embodiments. In other words, the sectorization switching unit 501 and/or the measurement unit 502 may be an element that comprises one or more arithmetic logic units, a number of special registers and control circuits .

An apparatus implementing functionality or some functionality according to an embodiment/example/implementation may generally include volatile and/or non- volatile memory (not illustrated in Figure 5), for example EEPROM, ROM, PROM, RAM, DRAM, SRAM, double floating-gate field effect transistor, firmware, programmable logic, etc. and typically store content, data, or the like. The memory or memories may be of any type (different from each other), have any possible storage structure and, if reguired, being managed by any database management system. The memory may also store computer program code such as software applications (for example, for the sectorization switching unit 501 and/or the measurement unit 502) or operating systems, information, data, content, or the like for the processor to perform steps associated with operation of the apparatus in accordance with embodiments. The memory, or part of it, may be, for example, random access memory, a hard drive, or other fixed data memory or storage device implemented within the

processor/apparatus or external to the proces sor/apparatus in which case it can be communicatively coupled to the

processor/network node via various means as is known in the art. Examples of an external memory include a removable memory detachably connected to the apparatus, a distributed database and a cloud server.

An apparatus implementing functionality or some functionality according to an embodiment/example/implementation of a base station, generally comprise different antenna

units/components/elements (not illustrated in Figure 5), the number of which is not limited to any particular number, and the type or types of antenna unit ( s ) /component ( s ) /element ( s ) not being limited to any particular wireless access

mechanism .

Further, an apparatus implementing functionality or some functionality according to an

embodiment/example/implementation of a base station, may comprise other units, like a network management interface unit and a radio controller unit .

The steps and related functions described above in Figures 2, 3 and 4 are in no absolute chronological order, and some of the steps may be performed simultaneously or in an order differing from the given one. Examples of such steps are steps 213-214, steps 313-314, steps 402-405 and steps 407- 413. Other functions can also be executed between the steps or within the steps. Some of the steps or part of the steps can also be left out or replaced by a corresponding step or part of the step. Examples of such steps include 203, 207, 211, 303, 307, 311 and 318.

Although in the above it is assumed that the same

sectorization pattern is used for uplink and downlink.

However, if user eguipments support different cells in uplink and downlink, different sectorization patterns may be used for uplink and downlink, and hence also the switching over from on sectorization pattern to another sectorization pattern happens independently for downlink and for uplink; the only change for the above described algorithms is that for uplink switching over decision all tests related to downlink are removed and for downlink switching over decision all test related to uplink are removed.

Although in the above it is assumed that a cell site

comprises more than one horizontal sector, it should be appreciated that the above described switching over between the classic and higher order sectorization patterns is implementable between one horizontal sector pattern and a pattern resulting to the one horizontal sector pattern being split by the vertical sectorization .

It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways . The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A method comprising: deploying a sectorization pattern in a cell; comparing at least one value indicating a load in the cell with a threshold; and

determining, based at least on the comparison result, whether or not to switch over from the used sectorization pattern to another sectorization pattern.

2. A method as claimed in claim 1, further comprising:

performing the comparing separately for a downlink and for an uplink .

3. A method as claimed in claim 1 or 2, further comprising: deploying the sectorization pattern cell sector-specifically; and

performing the comparing and determining cell sector- specifically .

4. A method as claimed in claim 1, 2 or 3, further

comprising : switching over between a lower order sectorization pattern and a higher order sectorization pattern in a cell sector; when the lower order sectorization pattern is deployed, comparing a load created by user equipments close to a base station providing the cell, the user equipments locating in the cell sector, to a first threshold value, and if the load is above the first threshold value, switching over to deploy the higher order sectorization pattern; and when the higher order sectorization pattern is deployed, comparing a load in an inner sector to a second threshold value and a load in an outer sector to a third threshold value, and if each comparison result indicate that the classic order sectorization value provides better capacity, switching over to deploy the lower order sectorization pattern .

5. A method comprising: measuring traffic in a cell; and classifying the measured traffic so that a measurement report indicates a load in a first area of the cell and a load in a second area of the cell.

6. A method as claimed in claim 5, further comprising performing the measuring and classifying separately for downlink and uplink.

7. A method as claimed in claim 5 or 6, further comprising performing the classifying according to a deployed

sectorization pattern so that when a higher order

sectorization pattern is deployed, the first area is an inner sector and the second area is an outer sector.

8. A method as claimed in claim 5, 6 or 7, further comprising performing the classifying according to a deployed

sectorization pattern so that when a lower order

sectorization pattern is deployed a load created by user eguipments in a cell sector and close to a base station providing the cell is the load in the first area, and a load created by other user eguipments in the cell sector is the load in the second area.

9. An apparatus comprising means for implementing a method as claimed in any of claims 1 to 8.

10. An apparatus as claimed in claim 9, the apparatus comprising at least one processor; and one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, provide the means for implementing.

11. A computer program product comprising program instructions adapted to perform any of the steps of a method as claimed in any one of claims 1 to 8 when the computer program is run.