GB2427796A

GB2427796A - Communication system, apparatus and method for simulating, designing or operating a communication system

Info

Publication number: GB2427796A
Application number: GB0616239A
Authority: GB
Inventors: Iain Marsden
Original assignee: Arieso Ltd
Current assignee: Arieso Ltd
Priority date: 2006-08-16
Filing date: 2006-08-16
Publication date: 2007-01-03
Also published as: GB0616239D0

Abstract

A method (500) of simulating or designing a wireless communication network supporting communication between a plurality of communication units across a plurality of communication cells, comprises performing a two-dimensional network simulation; extracting two-dimensional technical and geographical data from the two-dimensional network simulation and superimposing the two-dimensional technical and geographical data on a three-dimensional graphical representation.

Description

COMMUNICATION SYSTEM, APPARATUS AND METHOD FOR SIMULATING, DESIGNING OR

OPERATING A COMMUNICATION SYSTEM

Field of the Invention

This invention relates to wireless communication system, an apparatus and method for simulating, designing or operating a communication system. The invention is applicable to, but not limited to, a simulation tool and/or resource planning in a second or third generation wireless communication system.

Background of the Invention

Wireless communication systems, for example cellular telephony or private mobile radio communication systems, typically provide for radio telecommunication links to be arranged between a plurality of base transceiver stations (BTSs) and a plurality of subscriber units, often termed mobile stations (MSs) . Such telecommunication links are arranged to support digital and/or analogue communication signals.

Wireless communication systems are distinguished over fixed communication systems, such as the public switched telephone network (PSTN), principally in that subscriber units/mobile stations move between coverage areas, where communications in the different coverage areas are served by different BTS (and/or different service providers) In doing so, the subscriber units/mobile stations encounter a variable radio propagation environment.

Thus, in order for a system planner to ensure that there is acceptable communications across a wide geographical coverage area, which allows wireless communication signals to be transmitted to, and/or received from, the MSs at different geographical locations, a large number of communication parameters have to be determined.

Furthermore, the system planner/network provider needs to ensure that the communication network(s) are designed such that they meet peak usage demand, so that users can make calls as and when required.

In a wireless communication system, each BTS has associated with it a particular geographical coverage area (or cell) . Primarily, a particular ETS transmitter power level, together with the type, height and directionality of the antenna that is used, defines a coverage area where a ETS can maintain acceptable communications with MS5 operating within its serving cell. In addition, receiver sensitivity performance of receiving wireless communication units also affects a given coverage area. In large cellular communication systems, these cells are combined and often overlapped to produce an extensive and contiguous signal coverage area, whilst the subscriber units/mobile stations move between cells. The cell overlap region is deliberately designed into the system plan to ensure that subscriber units/mobile stations can successfully handover between cells.

A system design based on cells is typically based on an ideal cell pattern. However, an idealised cell pattern never occurs in practice, due to the nature of the terrain and the fact that cell sites and antennae are not ideally located on a regular grid pattern. Therefore, prior to system/network integration, a network designer uses radio-planning tools to estimate the radio propagation for each cell and consequently predict a corresponding coverage area. Based on these propagation models, the network designer is able to develop an initial plan for the network (prior to deployment of the network infrastructure) that is intended to minimise the expected interference. Once a specific infrastructure has been modelled, a simulation algorithm is run a large number of times, for a wide variety of subscriber distribution and parameters, i.e. location of MS5, activity status of MSs and transmit power employed by MSs operating in the network, in order to gain a statistical assessment of the network performance under the vast majority of operating conditions.

On the basis of the results of the software simulation, a variety of network parameter settings and site configurations (herein network parameter settings') are manually adjusted, such as a BTS antenna type, direction, power, height, location or radio resource management such as handover parameters, admission control, congestion control etc and other system parameters such as cell reselection, in order to improve the simulation results.

The software simulation algorithm is then re-run, re-run, and so on for further parameter alterations. Thus, the simulation phase is designed to converge to a set of parameter settings that allow the performance of the network to reach a predefined performance level, prior to network installation.

The simulation algorithms that are run are technology dependent. For example, different methods for assessing the network interference and quality are required for a Code Division Multiple Access (CIDMA) technology, as defined for implementing the third generation (30) mobile communication systems, as compared to the Time Division Multiple Access (TDMA) technique employed by the second generation (2G) global system for mobile communications (GSM) . An inherent feature of CDMA is that all mobile network users have access to the whole frequency bandwidth all of the time. Thus, a frequency reuse of the network is a well-known feature of CDMA based systems. This means that the power emitted by the subscriber units and the base stations, respectively termed user equipment (UF) and Node Bs in 30 parlance, must be tightly controlled.

In order to design, plan, investigate and develop CDMA based systems, a software-based simulation of the network is carried out to ascertain, in particular, the transmit power leve's employed by each Node B and each UE.

Part of a CDMA simulation involves solving certain mathematical formulations, for which there is no known closed-form' solution. For this reason a numerical technique is employed whereby an initial solution is guessed' and is iteratively modified until the true solution is obtained. In order to ascertain when the final solution is reached, a convergence criterion' is defined, and the solution is then said to have converged' A known iterative algorithm 100 used for power convergence in COMA-based simulation applications is illustrated in FIG. 1. The iterative algorithm 100 comprises two phases: (i) an initialisation phase 110, where all components of a network, such as communication cells and UEs etc., are executed as machine code; and (ii) an iteration phase 150.

In the initialisation phase 110, network information is read into computer memory, such as coverage information in step 115, Node B information in step 120, IJE information in step 125 and network parameters in step 130.

The iteration phase 150 comprises a series of computations. In this regard, for each UE and Node B in the network in step 155, the simulation computes a new transmit power in step 160. Once the transmit powers have been computed, the simulation is able to compute the levels of interference caused within each cell and to each of the UEs, as shown in step 165. At the end of the simulation's iteration, a determination is made as to whether the powers have converged, in step 170. If the powers have not converged, i.e. a definitive answer to the interference levels cannot be determined, the process loops 175 and one or more new transmit power level(s) for one or more UEs and/or Node Bs is/are used, as shown in step 155. However, if the powers have converged in step 170, the iterative power/interference level simulations end, as shown in step 180.

When simulating or designing a wireless communication system, or operating the communication system and adapting its performance in a reai- time manner, the system simulation revolves around two dimensional (2D) imagery of the technical performance indicators, which are often displayed geographically using typically a geographical information system (GIS) tool, as illustrated in the traditional 2D view of predicted radio signal in a cellular environment 200 of FIG. 2.

FIG. 2 illustrates the 2D radio propagation environment resulting from two base stations (node-Bs and sometimes referred to as cell-sites) 205, 210. The signal strength plots 215, 220 are illustrated with decreasing level as the prospective user equipment travels away from the base station. A region 225 indicates the boundary of the two sites where a user equipment may need to hand-over to the other site. As shown, known simulations use 2D information, and the network operators and system designers use these 2D simulation results to guess the rea-1ife causes for some of these effects. It is known that network operators and system designers may utilise camera pictures, taken from the respective prospective cell sites, in trying to determine the reasons for the 2D simulation effects.

Referring now to FIG. 3, a flowchart 300 describes the known mechanism for optimising a simulation that network operators and system designers have followed traditionally. The process involves two-dimensional troubleshooting of potential communication problems within the network. In this regard, System engineers or software simulation engineers need to observe the technical performance of the network in two dimensions in step 310 and, during the course of this, visually identify potential communication problem areas within the network in 2D imagery, as shown in step 315.

Based on the perceived communication performance, and one or more identified potential communication problems within the network, the System engineers or software simulation engineers then implement one or more changes to network parameters, as shown in step 320.

Based on 2D visualization of the network's technical performance, generally shown geographically as shown in FIG. 2, the effect of the one or more simulation/modelling change is re-assessed to identify whether the network performance has improved and/or the one or more potential communication problem is consequently resolved, as shown in step 325. One function of this re-visualisation' is to ensure that the performance of the network is not degraded as a result of the change(s). If the one or more potential communication problem(s) is/are resolved in step 325, then that part of the modelling/simulation is completed, in step 330. Otherwise, the process loops back to step 305, and further modelling changes are manually implemented and simulations re-run.

Thus, the current process is based around 2D imagery, is manually intensive and requires significant engineering experience in identifying potential problems and ensuring that the needs of the network can be satisfied by performing manual changes to network parameters. Thus, the process is prone to human error and inexperience.

Furthermore, sub-optimal changes to network parameters have a significant effect on the capital and operational budget expenditures, particularly when the cost of each site is of the order of lOOk-f,200k.

Therefore, in summary, the known processes can take an extremely long time to resolve unknown quantities, are inefficient and do not adequately address the requirements and needs of mobile operators who are focused on optimal spend for their capital and operational budgets. In addition, in cases where there is limited data presented inadequately in 2D, it is possible that a sub-optimal network design is achieved, where the network design merely meets rather than exceeds the network provider's minimum requirements.

Thus, there exists a need in the field of the present invention for an improved network-planning tool.

Furthermore, there exists a need to provide a cell-based communication system that can be continuously optimised through on-going simulations, wherein the aforementioned disadvantages may be alleviated.

Summary of the Invention

In accordance with one embodiment of the present invention there is provided an improved communication network, apparatus, network planning tool and method for continuously optimising a communication system's performance through more accurate on-going simulations, as claimed in the appended Claims.

In one embodiment of the present invention, a method of simulating or designing a wireless communication network supporting communication between a plurality of communication units across a plurality of communication cells, comprises performing a two-dimensional network simulation; extracting two-dimensional technical and geographical data from the two-dimensional network simulation; and superimposing the twodimensional technical and geographical data on a three-dimensional graphical representation.

By superimposing two-dimensional technical and geographical simulation data on a three-dimensional graphical representation, a Network Operator or System Designer is able to detect and thereafter reduce, minimise or eliminate communication problems within the Network and make better engineering decisions In one embodiment of the present invention, the method may further comprise displaying the three-dimensional graphical representation of superimposed two-dimensional simulated data. This may allow the Network Operator or System Designer to more readily visualise effects causing communication problems within the Network and thereafter determine one or more Network parameters to adapt to reduce, minimise or eliminate communication problems within the Network.

- 10 - In one embodiment of the present invention, the method may further comprise interpreting the three-dimensional graphical representation of superimposed two-dimensional simulated data and identifying one or more communication effects relating to one or more identified problem area(s) In one embodiment of the present invention, the method may further comprise modifying one or more network parameter(s) and re-performing a two-dimensional simulation using the one or more modified network parameter(s) In one embodiment of the present invention, the one or more network parameter(s) may comprise one or more of the following: site mast height, sector azimuth, sector tilt, antenna type, transmit power level, communication service, desired coverage range or radio resource management parameter, such as one or more handover parameters, admission control, congestion control or cell re-selection.

In one embodiment of the present invention, the three- dimensional graphical representation may comprise a Google EarthTM software application.

In one embodiment of the present invention, the method may be applied to a wireless W-CDMA, CDMA, TDNA, FDMA or CFDMA communication network.

In one embodiment of the present invention, the method may be applied to one or more of the following: a static - 11 - simulation of a wireless communication network; a dynamic simulation of a wireless communication network; an off- line optimisation of a wireless communication network; or an on-line (or substantially near-real-time) optimisation of a wireless communication network.

In one embodiment of the present invention, a communication unit, such as an Operations and Management Centre (ONC) of a 3G communication network, may be adapted to support the hereinbefore described method.

In one embodiment of the present invention, a storage medium may store processor-implementable instructions for controlling a processor to carry out the hereinbefore described method.

Typically the method may be applied as part of an automatic cell planning tool (ACP) or drive-test post- processing tool or performance management tool or capital planning tool or radio-planning tool and utilised in the selection of radio base station sites, tune transmitter parameters and/or select antenna settings, trouble shooting, decisions on capital and operational spend.

It is envisaged that data relating to the superimposing of 2D simulation data in a 3D graphical location form and associated analysis and results may be stored in a database and relate to any, or any combination, of the following: geographical area to be covered by the network, the number of handsets for which the simulation is to be generated, the status of the handsets i.e. whether moving or static, the power emissions from the - 12 - handsets and/or base stations, settings of the base stations themselves, and in general any data which can be treated as a predetermined parameter which will not in practice change or change with little or no impact on the network performance.

The 2D simulation data in a 3D graphical location form can be used to generate data results on a real-time basis. As an example, if the network geographical area includes a heavily used transport link, such as a motorway, commuter route or rail line, then the usage characteristics may vary largely during any given day as a result of rush hour traffic going in a first direction at the start of the day and the reverse direction at the end of the day with, in between those times, relatively less usage. Thus, the database may be configured to hold data to allow a simulation of the use of the network at each of these different usage instances.

In one embodiment of the present invention, a wireless communication network supports communication between a plurality of communication units across a plurality of communication cells. The wireless communication network comprises logic for performing a two-dimensional network simulation; logic for extracting two-dimensional technical and geographical data from the two-dimensional network simulation; and logic for superimposing the two- dimensional technical and geographical data on a three- dimensional graphical representation.

In one embodiment of the present invention, the logic for performing a simulation, logic for extracting and/or - 13 - logic for superimposing are located in an Operations and Management Centre of the wireless communication network.

In one embodiment of the present invention, a simulation tool for a wireless communication network comprises the aforementioned logic elements.

In one embodiment of the present invention, a computer program product comprises executable program code for simulating a wireless communication network, the computer program product comprising program code for performing a two-dimensional network simulation; extracting twodimensional technical and geographical data from the two- dimensional network simulation; and superimposing the two-dimensional technical and geographical data on a three-dimensional graphical representation.

In one embodiment of the present invention, an apparatus, comprises a memory; a processor coupled to the memory; and program code executable on the processor, the program code operable for: performing a twodimensional network simulation; extracting two-dimensional technical and geographical data from the two-dimensional network simulation; and superimposing the two-dimensional technical and geographical data on a three-dimensional graphical representation.

In summary, the inventive concept of the present

invention proposes an improvement to the known manual method by specifically proposing a process around using 3D graphical software applications, such as Google EarthTM, and automatically or otherwise using 3D - 14 - visualization data as well as underlying morphology satellite imagery data to best plan, optimize, spot errors in underlying data and expansion of the network.

Brief Description of the Drawings

FIG. 1 is a flow diagram outlining the conventional iterative algorithm used in modelling a wireless communication system.

FIG. 2 illustrates a schematic diagram of a 2D simulation.

FIG. 3 illustrates a known process for simulating a wireless communication system.

Exemplary embodiments of the present invention will now be described, with reference to the accompanying drawings, in which: FIG. 4 illustrates a block diagram of a cellular radio communications system adapted to support the various inventive concepts of a preferred embodiment of the present invention; FIG. 5 illustrates a flow diagram outlining the simulation algorithm employed in accordance with one embodiment of the present invention; and FIG. 6 is a schematic diagrammatic illustration of a 2D simulation overlay on 3D graphical software data according to embodiments of the present invention.

- 15 -

Description of Embodiments of the Invention

The simulation and modelling of a wireless communication system is highly complex, primarily due to the large number of wireless communication elements, such as base stations/ Node Es and subscriber units/ user equipment (UE) and the consequent and numerous performance capabilities of each element. The inventor of the present invention has recognised that traditional methods of basing simulation decisions on out-of-date morphology data, 2D imagery and the inherent problems associated with human experience and errors is impacting network designs in terms of inefficiency in resolving network problems.

One embodiment of the present invention is described with reference to a simulation of a 3rd generation cellular communication system, such as a ODNA based UMTS universal mobile telecommunication system as defined by the European Telecommunication Standards Institute (ETSI) However, the inventive concepts are equally applicable to any other wireless access technologies, such as GSM, frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), etc. Simulating a CDMA based network is primarily concerned with evaluating the powers transmitted by Node Bs and subscriber units. Severe interference exists between these entities. The level of interference is also dependent on their relative positions, which needs to be - 16 - evaluated within the simulation. In order to combat such levels of interference, both subscriber units (UEs) and the Node Bs must adopt appropriate power levels, in order to achieve the predefined quality of service (Q0S) for the end user.

It is envisaged that the inventive concepts can be applied in a real-time manner, say, by an Operations and Management Centre (OMC) of a 2G or 3G network, to simulate a real-time performance of the network. In this manner, the ONC is able to continuously optimise the performance of the network dependent upon the prevailing and variable conditions. Alternatively, it is envisaged that the simulation aspects of the present invention can be applied by a Network Operator in the initial design or expansion of a wireless cellular communication network.

Thus, the foregoing description details how the inventive concept can be applied to a practical UMTS network, and preferably to the adaptation of system parameters in a pseudo real-time manner as a result of the simulation.

Referring first to FIG. 4, a cellular-based telephone communication system 400 is shown in outline, in accordance with a preferred embodiment of the invention.

In the preferred embodiment of the invention, the cellular-based telephone communication system 400 is compliant with, and contains network elements capable of operating over, a universal mobile telecommunication system (UMTS) and/or a general packet radio system (GPRS) air-interface.

- 17 - Generally, the air-interface protocol is administered from base transceiver sites, referred to under UMTS terminology as Node-Bs, within the network architecture.

The Node Bs are geographically spaced apart - one Node B supporting a cell (or, for example, sectors of a cell) A plurality of subscriber terminals (or user equipment (UB) in UMTS nomenclature) 412, 414, 416 communicate over radio links 418, 419, 420 with a plurality of Node-Es 422, 424, 426, 428, 430, 432. The system comprises many other UEs and Node Bs, which for clarity purposes are not shown.

The wireless communication system, sometimes referred to as a Network Operator's Network Domain, is connected to an external network 434, for example the Internet. The Network Operator's Network Domain (described with reference to both a 3 generation UMTS and a 2r)d generation GSN system) includes: (1) A core network, namely at least one Gateway GPRS Support Node (GGSN) 444 and/or at least one Serving GPRS Support Nodes (SGSN); and (ii) An access network, namely: (ai) a GPRS (or UMTS) Radio network controller (RNC) 436-440; or (au) Base Site Controller (BSC) in a GSM system and/or (bi) a GPRS (or UNTS) Node B 422-432; or (bii) a Base Transceiver Station (BTS) in a GSM system.

- 18 - The GGSN/SGSN 444 is responsible for CPRS (or UNTS) interfacing with a Public Switched Data Network (PSDN) such as the Internet 434 or a Public Switched Telephone Network (PSTN) 434. A SGSN 444 performs a routing and tunnelling function for traffic within say, a GPRS core network, whilst a GGSN 444 links to external packet networks, in this case ones accessing the GPRS mode of the system The Node-Es 422-432 are connected to external networks, through base station controllers, referred to under UMTS terminology as Radio Network Controller stations (RNC), including the RNC5 436, 438, 440 and mobile switching centres (MSCs), such as MSC 442 (the others are, for clarity purposes, not shown) and SGSN 444 (the others are, for clarity purposes, not shown) Each Node-B 422-432 contains one or more transceiver units and communicates with the rest of the cell- based system infrastructure via an ub interface, as defined in

the UMTS specification.

Each RNC 436-440 may control one or more Node-Es 422-432.

Each MSC 442 provides a gateway to the external network 434. The Operations and Management Centre (OMC) 446 is operably connected to RNC5 436-440 and Node-Bs 422-432 (shown only with respect to Node-B 426 for clarity) . The OMC 446 administers and manages sections of the cellular telephone communication system 400, as is understood by those skilled in the art. A location registry function 480, comprising home location register and visitor - 19 - location register details, is shown at a high level in the system architecture, so that the location information is system-wide. A skilled artisan would appreciate that the location registry function 480 may, in alternative embodiments, be operably coupled to lower level elements such as the SGSN 442, 444, a GGSN (not shown) or the OMC 446.

In one embodiment of the present invention, the 0MG 446 has been adapted to perform a real-time simulation of the UMTS network. In this regard, the 0MG 446 has been adapted to automatically export and use the 2D simulation data into 3D graphical data, such as the Google-EarthTM 3D application, in order to generate a 3D graphical representation of 2D simulation data. This 3D graphical representation, for example, may be used to identify a real problem that exists with a particular simulation effect, such as buildings, forestry, a hilly region, etc. In one embodiment of the present invention, it is envisaged that, in addition to 3D location information, other data such as density of users and/or user profiles may be incorporated into the results.

Referring now to FIG. 5, a flow diagram 500 outlines the simulation algorithm employed in accordance with one embodiment of the present invention. The process commences in step 510 with the simulation tool performing an analysis. Once the simulation has been completed, the 2D data (together with any other additional information, such as user density or user profiles) is exported to a - 20 - 3D graphical software package, as defined by the Network Operator or System Designer, as shown in step 515.

Thereafter, the Network Operator or System Designer superimposes the 2D data on the area selected from the 3D graphical software package to provide a 3D representation of the 2D simulated data. The Network Operator or System Designer is then readily able to identify the true real- life nature of many simulation effects, as illustrated in step 520.

In one embodiment of the present invention, it is envisaged that the software tool may feed back pertinent information identified in the 3D representation to be stored, as shown in step 525.

In this regard it is envisaged that a system designer could identify high importance areas (from satellite photography), or perceived problem areas - i.e. challenging morphological features and feed these back to an ACP for further analysis.

In one embodiment of the present invention, the algorithm within thesimulation tool that uses the 3D graphical data (say from a 3D graphical software package) on which to overlay the 2D simulation results process, may be configured to resolve network issues or prioritize network expenditure. Notably, this is not a manual process - the ACP is configured to assess the cost of making a change to the network, and also the value that the change brings, i.e. X% improvement in coverage area.

On the basis of this information it will make a decision about a costbenefit trade-off.

- 21 - In one embodiment of the present invention, the process continues in step 530 with the Network Operator or System Designer utilising the visual 3D representation data of the 20 simulation results to determine one or more network parameters to be adapted to improve the communication performance of the network. The simulation may then be re-run with the one or more adapted parameters, as shown in the process loop of FIG. 5.

It is further envisaged that an algorithm to perform an automatic adjustment of parameters to overcome network problems or network expansion decisions may be used, with such an algorithm based on heuristic methods. In this manner, the automatic adjustment of parameters may provide an optimum combination of configuration for resolution of any identified potential communication problem.

Referring back to FIG. 4, in one embodiment of the present invention, it is envisaged that the inventive concept may be used in a dynamic simulation of a wireless communication network. In this regard, it is envisaged that a processor in the ONC 446 of FIG. 4 runs the simulation program. However, in alternative embodiments, it is envisaged that such a concept could be implemented in software in any element operably coupled to the ONC 446. Alternatively, the improved simulation algorithm may be located within any other element within the infrastructure, such as a separate analysis platform, or even distributed within a number of elements if appropriate. For example, the improved simulation - 22 algorithm could be implemented within the radio access network (RAN) of the cellular infrastructure equipment and/or it may be implemented as a stand-alone element/function on an adjunct platform.

In one embodiment of the present invention, it is envisaged that, following the 2D simulation being performed, the method comprises performing a simulation; directly, seamlessly or otherwise displaying the results geographically in Google EarthTM or similar 3D location software package. The results of the 3D presentation may then be observed by the Network Operator or System Designer, so that they are able to identify key aspects of the simulated data in a 3D manner.

It is envisaged that the 3D software application may comprise 3D morphology data, satellite imagery, and/or 3D building profiles. Furthermore, any automatic re- simulating with modified system parameter, antenna-type or height/erection may result in a decision to decommission an existing site to achieve the business goals and objectives of the Network Operator.

Thus, employing the inventive concept may lead to a higher quality radio system, better targeted network expansion and quality drive, and ultimately a better deployment of the Network Operator's capital and operational expenditure. Furthermore, the inventive concept may be equally applicable to automatic network optimisation techniques, network expansion planning, automatic cell planning tools, planning tools, drive- test - 23 - post-processing tools, performance management tools, capital planning tools, etc. In one embodiment of the present invention, the 3D graphical representation of the 2D simulated data may be used to discard quickly areas of bad performance in commercially and from marketing prospective unimportant areas providing very low revenues for the operator. In one embodiment of the present invention, the 3D graphical representation of the 2D simulated data may be used to direct investment into areas of high importance. In one embodiment of the present invention, it is also envisaged that the 3D graphical representation of the 2D simulated data may be used to identify errors made in underlying data displayed by the Network Operator.

More generally, the improved process of utilising a 3D graphical representation of 2D simulated data may be used, say, in the OMC 446 according to one embodiment of the present invention, in any suitable manner. For example, new apparatus may be added to a conventional communication unit. Alternatively existing parts of a conventional communication unit may be adapted, for example, by reprogramming one or more processors therein.

As such the required adaptation may be implemented in the form of processor-implementable instructions stored on a storage medium, such as a floppy disk, hard disk, programmable read only memory (PROM), random access memory (RAM) or any combination of these or other storage media.

- 24 - In an alternative embodiment of applying the aforementioned inventive concept in a preliminary network design simulation process, as compared to a real-time monitoring and adjustment of system parameters as described above, it is envisaged that the configuration of the hardware or software or firmware platform need not be static. In this regard, by arranging for the configuration of the network to vary in time, according to a pre-programmed sequence of events stored in the computer, the timevarying dynamic nature of the network can be precisely studied.

In this case, the Network Operator may define a dynamic scenario by specifying the manner in which one or more parameter(s) of the network changes with time, or alternatively the behaviour is predicted using location based information of the mobiles or is determined from network data logged as the network is operating. The sequence is then stored in computer memory.

Referring now to FIG. 6, a schematic representation of a 2D simulation with a 3D overlay process 600 is illustrated according to embodiments of the present invention. In particular, FIG. 6 illustrates a 3D view of simulation results over laid on terrain with land-use and building positions 615 displayed. Two base stations/cell sites 605, 610 are illustrated. 2D data relating to targeted coverage areas, in the form of high signal strength coverage area 620, medium signal strength coverage area 625 and low signal strength coverage area 630, is also superimposed on the 3D software package. In this manner, when 2D simulated data is placed on the 3D - 25 - representation, it is easy to see whether one or more buildings (or in alternative views, forestry or any other obstacj.e) may be affecting the performance of the network in particular areas.

In one embodiment of the present invention, the at least one antenna or system parameter that is modified in response to better identification of the problem areas, may comprise one or more of the following: BTS antenna type, direction, power, height, location or radio resource management such as one or more handover parameters, admission control, congestion control, etc. and other system parameters such as cell reselection, in order to eliminate any perceived problem.

One embodiment of the present inventive concept has been described with regard to a cellular telephony communication system, such as the universal mobile telecommunications standard (UMTS) . It is envisaged that the inventive concept is equally applicable to other wireless ODMA, TDMA, FDMA or OFDMA communication systems.

It is also within the contemplation of the invention that alternative radio communication architectures, such as private or public mobile radio communication systems could benefit from the inventive concept described herein.

It is also within the contemplation of the present invention that the inventive concepts are not limited to use in simulating a wideband CDMA network. It is envisaged that the inventive concepts are equally applicable to any scenario where there exists a need to - 26 - plan, troubleshoot and expand a network based on geographical data and morphology. In particular, it is envisaged that the inventive concepts can be applied to any radio network, such as: static simulation of radio networks, dynamic simulation of radio networks, off-line optimisation of radio networks, on-line (or near-real- time) optimisation of radio networks, etc. Clearly, a skilled artisan would appreciate that a vast array of applications and opportunities are made available to users through use of the inventive concept described herein. In this regard, the examples provided above highlight only a snapshot of these.

It will be understood that the wireless communication system, improved ONC and/or improved method for resource (re-)planning, as described above, may provide one or more of the following advantages that could not be reliably obtained using existing 2D simulation methods: (i) It significantly reduces the time it takes a Network Operator to detect and thereafter reduce, minimise or eliminate communication problems within the Network.

(ii) It enables Network Operators to more accurately prioritize their Capital and Operational spend. Hence, employing the inventive concept may lead to a higher quality, as well as a less-costly radio system.

(iii) The inventive concept may be equally applicable to automatic network optimisation techniques, to automate the whole process of radio network design for cellular operators. Furthermore, it may be applied to - 27 drive-test post-processing, performance management and any other tool that uses a graphical interface capability as part of its simulation tool's process.

(iv) The inventive concept is equally applicable to on-going and substantially real-time adjustment of a wireless communication network, a feature that cannot be envisaged in today's large wireless networks.

(v) It significantly reduces the time it takes a Network Designer to design and study the dynamic behaviour of the network.

It will be appreciated that any suitable distribution of functionality between different functional units or controllers or memory elements, may be used without detracting from the inventive concept herein described.

Hence, references to specific functional devices or elements are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

Aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these. The elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit or IC, in a plurality of units or ICs or as part of other functional units.

Although the present invention has been described in connection with some embodiments, it is not intended to - 28 - be limited to the specific form set forth herein.

Rather, the scope of the present invention is limited only by the accompanying claims. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention. In the claims, the term comprising' does not exclude the presence of other elements or steps.

Furthermore, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Also, the inclusion of a feature in one category of claims does not imply a limitation to this category, but rather indicates that the feature is equally applicable to other claim categories, as appropriate.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed and in particular the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. In addition, singular references do not exclude a plurality. Thus, references to "a", "an", "first", "second" etc. do not preclude a plurality.

Thus, an improved network planning tool, a cell-based communication system that can be continuously optimised - 29 - through on-going simulations, apparatus and methods of simulation therefor have been described wherein the aforementioned disadvantages associated with prior art arrangements have been substantially alleviated.

Claims

- 30 - Claims 1. A method (500) of simulating or designing a wireless

communication network supporting communication between a plurality of communication units across a plurality of communication cells, wherein the method comprises: performing a two-dimensional network simulation; extracting (515) two-dimensional technical and geographical data from the two- dimensional network simulation; wherein the method is characterised by: superimposing (515) the two-dimensional technical and geographical data on a three-dimensional graphical representation.
2. The method (500) of simulating or designing a wireless communication network of Claim 1 wherein the method is further characterised by displaying the three- dimensional graphical representation of superimposed two- dimensional simulated data.
3. The method (500) of simulating or designing a wireless communication network of Claim 1 or Claim 2 wherein the method is further characterised by interpreting (530) the three-dimensional graphical representation of superimposed two-dimensional simulated data and identifying one or more communication effects relating to one or more identified problem area(s) in response thereto.

- 31 -
4. The method (500) of simulating or designing a wireless communication network of any preceding Claim wherein the method is further characterised by modifying (530) one or more network parameter(s) and re-performing a two- dimensional simulation using the one or more modified network parameter(s)
5. The method (500) of simulating or designing a wireless communication network of Claim 4 wherein the one or more network parameter(s) comprises one or more of the following: site mast height, sector azimuth, sector tilt, antenna type, transmit power level, communication service, desired coverage range or radio resource management parameter, such as one or more handover parameters, admission control, congestion control or cell re-selection.
6. The method (500) of simulating or designing a wireless communication network of any preceding Claim wherein the three-dimensional graphical representation comprises a Google EarthTM software application.
7. The method (500) of simulating or designing a wireless communication network (400) of any of the preceding Claims, wherein the method is applied to a wireless CDMA, TDMA, FDMA or OFDMA communication network.
8. The method (500) of simulating or designing a wireless communication network (400) of any preceding Claim, wherein the method is applied to one or more of the following: - 32 - (i) A static simulation of a wireless communication network; (ii) A dynamic simulation of a wireless communication network; (iii) An off-line optimisation of a wireless communication network; or (iv) An on-line or substantially near-real-time optimisation of a wireless communication network.
9. A wireless communication network (200) adapted to support the method steps of any of preceding Claims 1 to 8.
10. A wireless communication unit, such as an Operations and Management Centre (OMC) of a third generation (3G) communication network, adapted to support the method steps of any of preceding Claims 1 to 8.
11. A storage medium storing processor-implementable instructions for controlling a processor to carry out the method steps of any of preceding Claims 1 to 8.
12. A simulation tool, adapted to support the method steps of any of preceding Claims 1 to 8.
13. A wireless communication network (400) supporting communication between a plurality of communication units across a plurality of communication cells, wherein the wireless communication network (400) comprises: logic for performing a two-dimensional network simulation; - 33 - logic for extracting two-dimensional technical and geographical data from the two-dimensional network simulation; wherein the wireless communication network (400) is characterised by: logic for superimposing the two-dimensional technical and geographical data on a threedimensional graphical representation.
14. The wireless communication network (400) of Claim 13 wherein the wireless communication network (400) is further characterised by logic for displaying the three- dimensional graphical representation of superimposed two- dimensional simulated data.
15. The wireless communication network (400) of Claim 13 or Claim 14 wherein the wireless communication network (400) is further characterised by logic for interpreting the three- dimensional graphical representation of superimposed two-dimensional simulated data and logic for identifying one or more communication effects relating to one or more identified problem area(s).
16. The wireless communication network (400) of any of preceding Claims 13 to 15 wherein the wireless communication network (400) is further characterised by logic for modifying one or more network parameter(s) and logic for re-performing a two-dimensional simulation using the one or more modified network parameter(s)
17. The wireless communication network (400) of Claim 16 wherein the one or more network parameter(s) comprises - 34 one or more of the following: site mast height, sector azimuth, sector tilt, antenna type, transmit power level, communication service, desired coverage range or radio resource management parameter, such as one or more handover parameters, admission control, congestion control or cell re-selection.
18. The wireless communication network (400) of any of preceding Claims 13 to 17 wherein the three- dimensional graphical representation comprises a Google Earth software application.
19. The wireless communication network (400) of any of preceding Claims 13 to 18, wherein the wireless communication network (400) supports CDMA, TDMA, FDMA or OFDMA communication.
20. The wireless communication network (400) of any of preceding Claims 13 to 19, wherein the logic for superimposing the two-dimensional technical and geographical data on a three-dimensional graphical representation is applied to one or more of the following: (j) A static simulation of the wireless communication network (400); (ii) A dynamic simulation of the wireless communication network (400); (iii) An off-line optimisation of the wireless communication network (400) ; or (iv) An on-line (or substantially near-real-time) optimisation of the wireless communication network (400) - 35 -
21. The wireless communication network (400) of any of preceding Claims 13 to 20, wherein the logic for performing a simulation, logic for extracting and/or logic for superimposing are located in an Operations and Management Centre (446) of the wireless communication network (400)
22. A simulation tool for a wireless communication network (400) supporting communication between a plurality of communication units across a plurality of communication cells, wherein the simulation tool comprises: logic for performing a two-dimensional network simulation; logic for extracting two-dimensional technical and geographical data from the two-dimensional network simulation; wherein the wireless communication network (400) is characterised by: logic for superimposing the two-dimensional technical and geographical data on a three- dimensional graphical representation.
23. The simulation tool of Claim 22 wherein the simulation tool is further characterised by logic for displaying the three-dimensional graphical representation of superimposed two-dimensional simulated data.
24. The simulation tool of Claim 22 or Claim 23 wherein the simulation tool is further characterised by logic for interpreting the threedimensional graphical representation of superimposed two-dimensional simulated - 36 - data and logic for identifying one or more communication effects relating to one or more identified problem area(s)
25. The simulation tool of any of preceding Claims 22 to 24 wherein the simulation tool is further characterised by logic for modifying one or more network parameter(s) and logic for re-performing a two- dimensional simulation using the one or more modified network parameter(s)
26. The simulation tool of Claim 25 wherein the one or more network parameter(s) comprises one or more of the following: site mast height, sector azimuth, sector tilt, antenna type, transmit power level, communication service, desired coverage range or radio resource management parameter, such as one or more handover parameters, admission control, congestion control or cell re-selection.
27. The simulation tool of any of preceding Claims 22 to 26 wherein the three-dimensional graphical representation comprises a Google EarthTM software application.
28. The simulation tool of any of preceding Claims 22 to 27, wherein the logic for simulating a performance of the communication network simulates CDMA, TDNA, FDNA or OFDMA communication.
29. The simulation tool of any of preceding Claims 22 to 28, wherein the logic for superimposing the two- - 37 - dimensional technical and geographical data on a three- dimensional graphical representation is applied to one or more of the following: (i) A static simulation of the wireless communication network (400) ; (ii) A dynamic simulation of the wireless corniriunication network (400); (iii) An off-line optimisation of the wireless communication network (400) ; or (iv) An on-line (or substantially near-real-time) optimisation of the wireless communication network (400)
30. The simulation tool of any of preceding Claims 22 to 29, wherein the simulation tool is located in an Operations and Management Centre (446) of the wireless communication network (400)
31. A cellular communication system (400) adapted to employ the simulation tool of any of preceding Claims 22 to 30.
32. Apparatus for use in a cellular communication system (400) adapted to employ the simulation tool of any of preceding Claims 22 to 30.
33. A computer program product comprising executable program code for simulating a wireless communication network, the computer program product comprising program code for: performing a two-dimensional network simulation; - 38 - extracting two-dimensional technical and geographical data from the two- dimensional network simulation; wherein the computer program product is characterised by: superimposing the two-dimensional technical and geographical data on a three-dimensional graphical representation.
34. An apparatus, comprising: a memory; a processor coupled to the memory; and program code executable on the processor, the program code operable for: performing a two-dimensional network simulation; and extracting twodimensional technical and geographical data from the two-dimensional network simulation; wherein the apparatus is characterised by: superimposing the two-dimensional technical and geographical data on a three-dimensional graphical representation.