WO2008004955A2

WO2008004955A2 - Indoor radio planning

Info

Publication number: WO2008004955A2
Application number: PCT/SE2007/000666
Authority: WO
Inventors: Johan Zetterblad; Ralf Schuh
Original assignee: Teliasonera Ab
Priority date: 2006-07-07
Filing date: 2007-07-06
Publication date: 2008-01-10
Also published as: WO2008004955A3

Abstract

The invention relates to a method and a computer program product for indoor radio planning, specifically, for automatic planning of indoor radio using a user friendly interface. The invention solves the problem of the rather complex methods in the prior art by providing a tool that is simple and still produces a useful result with a minimum of input data. The method comprises the steps of; receiving customer data comprising at least one parameter; retrieving complementary default data from a database; generating at least one radio plan with a floor plan with deployed radio equipment. Preferably, the costumer data at least comprises the parameter number of subscribers.

Description

Indoor radio planning

FIELD OF THE INVENTION

The invention relates to a method and a computer program product for indoor radio planning, specifically, for automatic planning of indoor radio using a user friendly interface. BACKGROUND

Today, there are many different dedicated indoor radio solutions available which can supply speech and/or data services. There is large amount of different wireless communications system available for indoor use. Fig. 1 shows some of the most common dedicated indoor solutions. In the future there will be even more possibilities like e.g. with the arrival of mobile WiMAX.

When it comes to indoor planning as it is today, it has been observed:

- The pre-study and final planning of the indoor systems takes too long. The pre-study from the customer request to the first quote can take up to 6 weeks. - Detailed building information may not be available and the planner has to visit the building which costs time and money.

- No tool is available in order to know which radio system(s) from the point of performance and price is best suited for a certain building/customer.

-For the pre-study and final planning the planner has to do lots of individual and time consuming work like: placing each antenna individually in the floor plans, calculating the settings of tappers and splitters in a distributed antenna system, etc.

- Indoor guidelines may be available but are difficult to maintain and if an experienced planner is leaving the company valuable information about indoor planning may be lost.

- Currently indoor planning involves different programmes like e.g. Excel for the link budget, PowerPoint and/or AutoCAD and Word for the final report with total cost for deployment and planning.

From the bullets above it can be seen that indoor planning can be quite complex and there may be only a few specialists in a company able to do this work.

Indoor planning tools or coverage prediction tools where the user has to place, individually in the building maps, the antenna and/or BS position can be found in prior art. These planning/prediction tools require the user interaction / knowledge of antenna placement, feeder, tapper/splitter selection and settings, etc. Some of these planning tools, which can use ray tracing with accurate CAD floor plans, can be quite accurate in order to calculate the radio coverage, but as building walls, furniture location may change frequently, such accurate planning is often not necessary.

Document US, Al, 2004/0,180,665 discloses a method for planning mobile radio coverage inside buildings. The method comprises the following steps: positioning a virtual antenna with certain predefined transmitting parameters at any available location inside the building and determining the size of the coverage by means of prediction methods for determining the high frequency receiving level. The coverage is changed by changing antenna parameters or adding a number of antennas. The result of the method is a best position of an antenna/s .

Document US, Al, 2005/0,059,405 discloses a method of planning a wireless local area network. The method comprises the steps of receiving floor plan data about a building; receiving coverage data and capacity data of the building and determining quantity, placement and configuration of access points. The result of the method is placements and numbers of access points in a WLAN configuration.

Document WO, Al, 02025506 discloses a method for designing, deploying or optimising a communications network comprising the steps of: generating a computerised model of a space with objects therein that have impact on the performance of the communications network; establishing a desired performance metric; modelling performance attributes of a number of components; specifying components to be used; specifying locations within said space for components; predicting a performance metric based on components and locations; and comparing predicted performance metric with desired performance metric. The desired performance metric may be installation cost. The result of the method is a generated model with wireless components located in the model.

These radio planning methods are all rather complex and therefore it has been desired to develop a tool that is simple and still produces an accurate result.

SUMMARY OF THE INVENTION

The invention solves the above problem by a method according to the independent claim 1 and a computer program product according to claim 15. The invention concerns a method making it possible to plan indoor radio systems automatically. The invention is applicable to all radio systems like:

GSM/GPRS/EDGE, WCDMA/HSxPA, WLAN, repeater solutions, distributed antenna systems, etc for speech and data services. The invention shows how the planning can be automated following a defined workflow. Different functions are used for the individual planning steps but new functions may be used or included if e.g. new radio systems arrive. Each function follows some design rules and parameters which may be set through a user interface or read from a database such as from the operator specific indoor guidelines and requirements. From the minimum number of required input information like number of users in the building the tool will compute the base station, antenna plan, component list, backhaul requirements, cost estimation, etc. With the invention, operators and/or indoor coverage planning companies can respond faster to customer request on dedicated indoor solutions. The best suited indoor radio/antenna system can be selected for the given building. All the components needed, cable lengths, etc are obtained and orders can be taken faster in order to start with the installation. The tool can be used for the pre-study/cost forecast and for the final planning of the indoor system. The tool can be also used as a more easily maintainable indoor guideline for network planners giving them all the parameter and rules for the indoor planning.

In the present invention all the planning is done automatically which with some slightly over dimensioning, e.g. to have a few more antennas, is often cheaper and more practical than to do a very accurate planning as in existent methods. The invention will save time for the planner for the pre-study and the final planning of the indoor project. The planning tool is easy to use and does not need expert knowledge in order to get some pre-study of the best radio system for the building under request.

However, the inventive method of automatic planning does not exclude the use of detailed building/floor information in order to place automatically the antennas at the "best" location in order to give the requested coverage level. The automatic planning tool includes the planning and cost forecast for the backhaul, base station or access points and/or the distributed antennas with feeder design in the building(s). According to a first aspect the invention provides a method for automatically planning an indoor radio system in a building comprising the steps of;

- receiving customer data (16) comprising at least one parameter;

- retrieving complementary default data (11, 12, 13, 14, 15) from a database; generating at least one radio plan (18) with a floor plan with deployed radio equipment. Preferably, the costumer data at least comprises the parameter number of subscribers.

According to a second aspect the invention provides a computer program product that when executed in a computer performs the above method.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows typical dedicated indoor solutions for different radio systems and antenna systems;

Fig. 2 shows schematically a method of an Automatic Indoor Radio Planning (AIRP) software tool;

Fig. 3 shows a graphical user interface (GUI) with input parameters for an indoor GSM design;

Fig. 4 shows a flowchart for planning of a GSM macro base station with passive coax distributed antenna system design; Fig. 5 shows a front view and a top view of a floor plan example from the planning for GSM macro Base Station with distributed antenna system; Fig. 6 shows a graphical user interface with input parameters for an indoor WLAN design;

Fig. 7 shows a flowchart for planning with WLAN access points and LAN with CAT5/6 cabling design;

Fig. 8 shows a front view and a top view of a floor plan example from the planning for of WLAN design with LAN CAT5/6 cabling;

Fig. 9 shows a graphical user interface showing different building shapes a user may want to select; and Fig. 10 discloses a schematic overview of the present invention.

Fig. 11 shows a graphical user interface showing a snapshot from an internet based map service.

Fig. 12 shows a graphical user interface showing a picture of a building selected by a user by use of the snapshot showed in Fig. 11.

DETAILED DESCRIPTION

Definitions

AIRP Automatic Indoor Radio Planning tool according to the invention AP Access Points

BS Base station

CAD Computer aided design

DAS Distributed Antenna System Erlang A unit of measurement of traffic density in a telecommunications system. The erlang describes the total traffic volume of one hour.

GSM Global System for Mobile communications

GPRS General Packet Radio Service HSxPA High Speed Downlink Packet Access and/or High Speed Uplink Packet Access

IPsec IP Security

MCM Multicasting Matrix (combiner/splitter box)

TRX Transceiver unit UMA Unlicensed Mobile Access

UMTS Mobile Telecommunications System

VoIP Voice over IP

WCDMA Wideband Code Division Multiplex Access

WiMAX Worldwide Interoperability for Microwave Access

The invention relates to a method of automatic indoor radio planning for dedicated indoor system including the base station(s), antenna system and required backhaul.

Fig. 1 shows typical dedicated indoor solutions for indoor radio in a building 101 connected via an outdoor base station 102 and backhaul lines to a public network/radio access network 103. Different radio systems and antenna systems are shown inside the building having different technical solutions such as repeaters, passive coax, leaky feeder, acive coax, fibre readio, radio over

CAT5/6/X cabling, pico BS (CAT5/6/x cabling), and WLAN APs (CAT5/6/x cabling). Such a system may accommodate GSM/GPRS/EDGE/WCDMA/-

HSxPA with centralised BS LAN router switch for public access.

Fig. 2 shows a schematic of the planning tool with input parameters and information 201, automatic planning functions 202, and outputs 203. The input parameters and information include basic input parameters (1), radio requirements (2) and possibly more detailed information (3).

The building owner or user has to supply some minimum basic input parameters (1) like the expected number of users in the building. Radio requirements like e.g. minimum required coverage level or speech Erlang per user are stored in some database, i.e. set as default data. This database can be built up from the indoor guidelines of the operator specifying the indoor and the general radio requirements (2). Possible data include: minimum coverage level; number of erlangs per subscriber for CS, PS, VoIP; maximum number of carriers

/TRXs units per cell; component lists with price information; deployment costs; digital line costs. More detailed information from the user or operator (3) will give a more accurate planning and cost forecast for the indoor system. Possible detailed information includes: building length, building width, number of floors and elevators (customer information); preferred cables, antennas (operator information).

The core of the automatic planning tool (4) is the use of various functions (5) which follow some rules in order to do the individual planning steps. In the illustrated embodiment of Fig. 2 the following algorithms and functions are executed: - Construct/calculate building/floor space plan based on the number of people /subscriber using typical office building design info with e.g. min/max square meter per user per floor;

- Calculate the number of cells, transceiver units needed in order to supply the required capacity. Define combiner/splitter as a function of carriers and cells;

- Calculate the antenna and/or distributed base station placement based on coverage requirements, path loss model.

—Allocate the antennas and/or distributed base station into feeders/cells architecture, e.g. horizontal/vertical DAS or star architecture depending on the operator requirements;

-Place all the other components like tapper, splitter, centralised switch, base station etc.;

-Connect distributed antennas or base stations to centralised base station/switch via e.g. CAT5 cable, coax or fibre using also tappers, splitters, switches, hubs, amplifiers;

-Compute tapper, splitter, BS settings and calculate the loss to each antenna.; and

-Possibly other core functions needed for the various indoor designs. The core algorithms and functions are known individually per se as seen for example in the above mentioned documents.

The planning can be done fore some specific radio system with or without attached antenna system and various building floor environments. At (6) a design selection may be made as to what radio and antenna system is to be used, and if a specific path loss model is to be used, or if an office space is specified, or the automatic planning should be made for all path loss models. Following the workflow as indicated in the overall planning is obtained. However as e.g. new functions can be added, the invention is not limited to this workflow and function order. Furthermore the algorithm/function like for defining the cell and feeder architecture with optimisation may also follow different rules depending e.g. on the operator's preference, as we will see later in some more detailed examples.

After the calculation for the indoor system(s) is done the user/operator will get the feeder and antenna plan (two or three dimensional plan) with all the parameter settings and also cost forecast for the installation. Outputs (7) like drawings, reports with parameters and component list are generated. The outputs (7) may include: floor plan with antenna, tapper, splitter, cable, base station location; list of all used components; backhaul requirements; overall components costs; deployment and final planning costs.

The planning tool (algorithms) may also be calibrated with existing indoor installation. In the design selection (6) and/or at basic input parameters (1) the user and/or operator may also decide to restrict some of the design parameters like maximum output power per antenna, etc. Furthermore the backhaul requirements (capacity needed between BS or centralised switch and the public network) is calculated from the maximum/average radio capacity of the indoor radio system. This can also include the overhead of different backhaul technologies like e.g. El lines, xDSL, El /ATM lines, or Ethernet/IP, etc in order to transport the traffic. The tool can also design multi-radio indoor radio system like for GSM and

WCDMA when using e.g. the same passive coax distributed antenna system. The tool could also be applied to cases where more than one building (with e.g. a distributed antenna system) get connected in order to get indoor coverage from one centralized base station location (in any building or at any outdoor location). The tool input/output interface could be also interactive which means e.g. that after the automatic indoor design has performed the initial design the user could add or shift some components (e.g. antennas) individually and the tool could than again calculate/produce the final architecture with all its information.

Use of the invention

The invention applies to indoor radio planning including base station, antenna location, feeder design, backhaul requirements and cost forecast. The planning is done automatically using some core algorithm (workflow with functions) after the user and operator has given some basic user information and radio system information. Such an automatic indoor planning tool is feasible as the indoor is a confined environment and the number of different installations / variations in installations can be limited to a few major design criteria / planning rules. Furthermore normally also the floor shapes/interior from an indoor radio planning perspective are quite similar from floor to floor except for the garage, ground floor and top floor which can be considered separately in the tool.

Two examples using the tool for indoor GSM and WLAN planning at two different buildings are discussed below. Fig. 3 shows a graphical user interface of the current preferred planning tool for indoor GSM. A screen window 301 comprises input fields where an operator can input building and user information such as: number of users; number of floors, separated into top floor, office floor, and garage/ground floor; number of elevators, equipment room floor; floor length, floor width, floor height; the operator may select building shape for the respective top floor, office floor, and garage/ground floor. Preferably there is a button 302 for optionally loading general building information from a database.

Further, the screen window 301 comprises input fields for radio system and operator information, such that GSM/GPRS/EDGE, WCDMA/HSxPA, WLAN, or WIMAX or more may be selected, as well as antenna feeder (passive coax, active coax, fibre radio, CAT5/6 cabling or more), base station system (macro, micro, Pico/WLAN APs, repeater or more), path loss model (open area, dense area, plaster walls, free space or more), backhaul interface and costs (Xdsal,El lines, El/ATM, STM-1/ATM VC4/12, Ethernet/IP or more). Preferably there are buttons for optionally loading operator requirements 303, and operator settings 304 e.g. from databases.

Further, the screen window 301 comprises command buttons, such as at 305, for plotting and creating reports, e.g. for producing an antenna/feeder/floor plan, estimate the total costs, viewing backhaul requirements, viewing operator requirements, and viewing building information.

In the example of Fig. 3, the planning is for a building with 9 floors, 520 subscribers using a macro GSM base station with a passive coax distributed antenna system. This could be for a typical average size company/office building in Sweden /Europe (Building shape Type 1 in Fig. 9 is used). Passive coax distributed antenna systems count for about 95% of all dedicated GSM indoor installations in Europe. The planning tool will consider voice and data for the capacity requirements.

In the illustrated example the user would press the "Load operator requirements" button 303 and the tool loads from a database the radio requirements, such as; Erlang/user, blocking, and average data requirement per user, etc in order to calculate the number of cells and number of carriers needed per cell. The load buttons in general will set all parameters if the parameters are not set manually via the user interface beside the rninimum required information like the "number of users" in the building. From the number of base stations (TRX units) the backhaul requirements can be calculated. In this example the operator preferred backhaul technology is El lines.

Fig. 4 shows a flow chart of used functions in order to design a GSM indoor system like selected in Fig. 3. Building owner / customer information 401 , as well as radio requirements/operator information 402, such as described in connection with Fig. 3 may be input. It should be mentioned again that in general the number of users/subscribers in the building would be sufficient in order to calculate the indoor design as in the planning tool according to the invention some core algorithm exists for calculating some virtual buildings as a function of the number of people in a building (see Fig.2). The flow chart also shows some optimisation loops 403, 404 for the antenna system for the case where the feeder loss is too high. If the feeder losses after using coax cable with larger diameter or by adding additional feeders are still too high the user would get an error message 405 e.g. indicating "Change BS location as feeder loss is too high to get required coverage level". However, the programme would still output the best possible antenna design for the given input and design parameters, preferably with an indication where feeder loss is too high.

The following core functions of the illustrated example are executed in the illustrated embodiment of the invention;

- calculate the number of cells, transceiver units needed in order to supply the required capacity. Get the correct combiner/splitter box at the base station (MCM). Define combiner/splitter as a function of carriers and cells; - calculate antenna placement based on building info, coverage requirements and path loss model. Place antenna inside or outside close to the elevator if good coverage in the elevator is required;

- allocate the antennas into the correct cells; decide on horizontal, vertical or any mixture of these two feeder/cell architectures;

- calculate the position of the splitters, tappers, couplers for the antennas for each feeder and each cell. Place the base station and MCM. Start with one feeder per cell; - connect distributed antennas over tappers, splitters,

MCM, etc to centralised base station with passive coax. Start with lowest coax diameter; - compute the tapper, splitter, BS settings and calculate the loss to each antenna.

After the user has pressed the antenna/feeder/floor plan button (Fig. 3) the user will obtain a floor-plan 406, preferably including antenna, tapper, splitter, cable, base station location; all settings for the base station, tappers and splitters; list of all used components; backhaul requirements; overall components costs; deployment and final planning costs.

A floor-plan feeder plot as shown in Fig. 5 may be produced with a front view showing nine floors at different heights and a top view of a ground floor. The AIRP tool in this case designed for three cells with vertical feeder architecture in order to supply the required capacity. The tool could also calculate any mixture of horizontal and vertical cell/feeder architecture but in this case as designed for GSM the emphasis was to cause minimum interference per cell to the outdoor network and therefore the tool designed a vertical cell architecture. There is one feeder per cell with 1/2" and 7/8" coax cable in Cell 1 and two feeders in Cell 2 and 3 in order to fulfil the required coverage level (maximum feeder loss). Each cell/feeder has antennas in each floor in this example but in general there could also be e.g. one antenna every second floor for each cell if the required coverage is fulfilled. One antenna is placed in the elevator in order to give good coverage in the elevator as selected by the user in Fig. 3. The tool also calculated all the coax cable lengths, feeder losses to each antenna, tapper and splitter settings, base station location, etc which can be printed in a report. As all the components are known the cost for the installation can be calculated including installation cost together with the backhaul requirements and costs, as the traffic demands are known (number of TRXs). The tool used omni-antennas for the indoor design as this was the operator preferred/recommended antenna for GSM indoor installation (see button "Load operator requirements" in Fig. 3). There are fewer antennas in the ground and garage floors compared to the office floors as these floors in this example are assumed to have a more open environment (lower radio path loss) and therefore large cell radii per antenna are possible and still meeting the required coverage level. For this chosen building the front and top view (ground floor) are shown. Generally everything could be shown in a three dimensional plot which may be necessary for more complicated building shapes. Fig. 6 shows a screen window with buttons and fields identical with Fig. 3.

This example shows input parameters for a WLAN design (e.g.: IEEE 802.1 Ig at 2.4GHz) which could be in a hotel with seven floors but WLAN coverage needs only to be supplied at the ground floor and the first two floors above the ground floor. CAT5 cabling with Ethernet 100Base-T interface is used in order to connect the WLAN access points to the centralised switch/hub location, which in this case, is in a room in the garage. In such a typical WLAN design each access point is connected to the centralised switch/HUB location resembling a star architecture.

Fig. 7 shows the flowchart in order to do the automatic design. Building owner / customer information 701, as well as radio requirements/operator information 702, such as described in connection with Fig. 6 may be input. The structure of the flowchart is very similar to the one used for GSM in the example of Fig. 4 but the different functions like number of carriers required per cell and/or antenna/access point location will now use the WLAN design criteria (sub-functions). For example in WLAN the access points are distributed in the building but in general also a WLAN design could contain some smaller distributed antenna system attached to each access point in order to give a more uniform coverage in the building. The capacity in this example (number of TRXs per access point) considers the average data and VoIP (speech) usage per user in this building. For VoIP in this specific example it also considers the overheads in the case of UMA deployment with the protocol overhead due to IPsec when calculating the number of carriers needed per AP and the total capacity in the backhaul. The flow chart also shows some optimisation loops 703, 704 for the antenna system for the case where the CAT5 losses are too high. If the CAT5 losses after using better CAT5 or by adding additional switches are still too high the user would get an error message 705 e.g. indicating "Change centralised switch location as CAT5/6 cable length is too long or use optical fibre". The following core functions of the illustrated example are executed in the embodiment of the invention;

- calculate the number of carriers per access point needed in order to supply the required capacity. Considers also overheads like e.g. for VoIP in the case of UMA using IPsec. - calculate the antennas/WLAN APs placements based on the coverage requirements and path loss model;

- place additional switches if required. Start with no additional switch per feeder to the WLAN APs;

- connect WLAN APs to the centralised switch location. Start with lowest grade CAT5 or CAT6 cable; and

- compute length/loss from centralised switch/hub to each WLAN AP. A floor-plan feeder plot as shown in Fig. 8 may be produced similarly to Fig. 5. Fig. 8 shows the WLAN floor plan cabling and WLAN access point locations. As this building is more square than the other above, the top view shows that there are four antennas per floor. The architecture is a star architecture with each access point directly over a single cable connected to the centralised LAN Router/Switch room. The maximum cable length in this example is about 60 meter and no cable extender/amplifier is necessary. The tool can also calculate the maxim/average required backhaul capacity from the number of access points and TRX units in order not to limit the radio capacity.

As mentioned before, in these examples the "simplest" antenna floor plan is shown which, even if not used for the final installation, can be used to get some pre-study for the feeder/antenna/access point design with a cost forecast. In general a more "complex" antenna floor plan e.g. in three dimensions with the exact building /floor shapes can be generated using the planning tool according to the invention.

User information:

Regarding the required user/building information as input to the planning tool according to the invention the complexity ranges from just inputting the number of users to supplying an accurate CAD drawing of the various floors in the building. In the table below, Table 1, Option 1 in this sense has the lowest complexity from the point of required user information. The tool adapts to the amount of input supplied by the user of the tool by loading necessary default data from databases. The user may replace default data by providing detailed information.

Table 1

In indoor installations typically antennas get installed along the corridors (not e.g. in rooms, see also total floor length definition in Fig. 9). It is also often cheaper to have a slightly over dimensioned installation with respect to the number of antennas (assuming higher radio path loss) then to do a more accurate and time consuming coverage level simulation with exact floor plans and/or even doing coverage measurements with test transmitters in the building. Therefore from practical experience and as also floor plans with furniture and walls often get changed option (3) of the building/user information is sufficient for the final plan whereas option (1) is sufficient for the pre-study and more "simple" building shapes or smaller installations. In the examples above for GSM and WLAN indoor coverage Option 3 was taken.

In case the user only supplies the number of users in the building for the pre-study the tool can construct a virtual building (length/width/height/number of floors) based on typical buildings for offices or hotels, e.g. in Europe. Equations for efficient/typical/spacious office space requirements per user in these buildings can be found in the prior art. From these and also assuming a more pessimistic indoor radio environment (e.g. many small single rooms -> higher radio path losses) the tool can do the pre-study and give some cost forecast. The user may also calibrate the building function with typical building shapes in his country where indoor installations have been done hi order to get higher accuracy.

Fig. 9 shows a window screen with a number of typical building shapes 901 - 905 which the user may select. With this "option" in the tool the user can select the building shape and/or the different floors (office floor, ground floor, garage) for which the indoor planning should be done.

Referring to Fig. 9, a user may manually select a type of building shape relating to the shape of the building in question. The dashed lines indicate how these buildings shapes can be transformed into two dimensional antenna feeder plans. In the illustrated antenna plan the total floor length instead of the building length will be plotted. More generally, the user may also supply actual drawings or a building plan (building shapes of CAD drawings) of the buildings/floors for the planning tool by means of a load button 906.

In Fig. 10 an embodiment of the invention is schematically shown. Default or input parameters relative to backhaul 11, radio systems 12, radio stations 13, antenna systems/design 14 and other possibilities 15 are combined with at least the minimum of inputs/parameters 16 in the tool 17 as described above to produce at least one solution 18 which may be optimised with regard to technical or economical aspects. Fig . 11 shows a graphical user interface of an internet based map service.

A screen window 111 comprises input fields where an operator can input building address information 112. After the operator provides the address in the address input field 112, a picture of the building is obtained.

Fig. 12 shows a picture 121 of a building 122 obtained by use of the interface shown in fig 11. The shape, length, width, height and/or more detailed information, such as type of building, of the building may be obtained from the picture. It may also be possible to see different shapes of separate floors of the building. The internet based map service and the planning tool may be integrated within one internet based planning tool. After entering the address the internet based planning tool may automatically detect the shape, length, width, height and/or more detailed information of the building. It may also be possible to estimate the number of people inside the building by use of the parameters; type, length, width and height of the building.

The method of automatic planning allows "real tune" or parallel computing of all indoor radio and antenna solutions (all possible combination, e.g. GSM with passive coax or fibre radio or WCDMA together with WLAN and CAT5 cabling and passive coax) in conjunction with the prices for the individual design steps (by connecting to the cost/data base of the individual components or e.g. deployment work). Already during the design process the tool allows identification of the best technical/economical indoor solution and will suggest the best technical/economical solution which otherwise may have been never found. The combination of all possible radio system, radio station and antenna system solutions gives lots and lots of possible solutions (Number of Radio Systems * Number of Radio Stations * number of Antenna system designs), but as the present invention allows combinations such as (WCDMA & WLAN) + pico solution + (CAT5 & passive coax DAS) the number of possible solution goes exponential. In existent methods a designer would never find the best technical/economical solution but with the invention this can be done and is only a question about computer power and also how the algorithms are defined in order to select/combine different solutions during the design.

The invention can compute all different combinations with cost forecast but the present invention can also limit the number of combinations by excluding some solutions in some steps during the design based on the cost (or using e.g. some genetic algorithm (birth/death algorithm to find the best solution without computing all possibilities)) or predefining a smaller set of default input parameters from the default database. Of course the solution, depending on the input parameters (wishes), may be just a "simple" solution like e.g. macro GSM base station with passive coax solution.

In an embodiment of the invention a predefined set of default data are used. In this embodiment the computation only considers a limited number of predetermined alternatives, e.g. only two different antennas may be used or the like. These settings are made by an operator and may be done in order to simplify the computation. As a further example, the operator may set up a default setting that the computation only uses one type of pico base station in the calculation. Today pre-studies and final plans of indoor radio systems are very time consuming and expensive. In the design process detailed building information may not be available and today there is no tool available to know what wireless system would be optimal for a given building structure. Pre-study and planning involve laborious and time-consuming experiments and measurements at the location. The invention relates to a planning tool that automatically calculates a good enough planning of base station locations and directional profiles. A user only inputs basic data, such as number of people, desired coverage level, estimated Erlang/user, number of floors, floor size, basement, loft and so on. Backhaul requirements are calculated from the requested capacity. The resulting plan is plotted. The invention is suitably implemented in a computer program. The advantage of making a programme for planning of indoor radio systems that is performed automatically, with no detailed input data and no field measurements and for any kind of wireless system, is that the planning is automatically plotted and required equipment and its cost is automatically listed.

Claims

1. A method for automatically planning an indoor radio system in a building comprising the steps of;

- receiving customer data (16) comprising at least one parameter; - retrieving complementary default data (11, 12, 13, 14, 15) from a database;

- generating at least one radio plan (18) with a floor plan with deployed radio equipment.

2. A method according to claim I₅ wherein the method is optimised with respect to coverage/cost/capacity.

3. A method according to any of the preceding claims, wherein the costumer data at least comprises the parameter number of subscribers.

4. A method according to any of the preceding claims, wherein the customer data further comprises data representing; building length, number of floors (width and height), indoor environment, and/or number of elevators and position of elevators.

5. A method according to any of the preceding claims, wherein the costumer data further comprises data disclosing the shape of the building.

6. A method according to any of the preceding claims, wherein the costumer data further comprises a CAD-drawing of the building.

7. A method according to any of the preceding claims, wherein the step of generating the radio plan comprises calculating iteratively and determining configuration of a number of components in the system based on at least the number of subscribers.

8. A method according to any of the preceding claims, wherein the complementary default data comprises a floor plan.

9. A method according to claim 4, wherein the floor plan is selected by a user from a number of default floor plans.

10. A method according to any of the preceding claims, wherein the complementary default data includes; minimum coverage level, number of erlangs and/or data requirements per subscriber for CS, PS, VoIP; maximum number of caπiers/TRXs units per cell; prices of the components; deployment costs; and/or digital line costs.

11. A method according to any of the preceding claims, wherein the step of generating a radio plan further comprises selecting a path loss model if the customer data does not include a floor plan.

12. A method according to claim 1 , wherein the method further generates backhaul requirements.

13. A method according to claim I₅ wherein the customer data is provided by a user via a graphical user interface.

14. A method according to claim 1, further comprising the steps of:

- generating a picture ( 121 ) of a selected building ( 122) by use of an internet based map service (111); and

- retrieving data representing information of said building ( 121 ) by use of said picture (121.

15. A method according to claim 14, wherein said data representing building information comprises at least the length of the building, shape of building and width of building.

16. A method according to claim 14 or 15, wherein said data representing building information further comprises height of building and type of building

17. A method according to claim 14 to 16, wherein a number of subscribers inside said building is obtained by using said data representing building information.

18. A method according to any of the preceding claims, wherein the generating step comprises the following:

- Construct/calculate building/floor space plan based on the number of subscribers using typical office building design info with min/rnax square meter per user floor;

— Calculate the number of cells, transceiver units needed in order to supply the required capacity, and define combiner/splitter as a function of carriers and cells; - Calculate the antenna and/or distributed base station placement based on coverage requirements, path loss model;

- Allocate the antennas and/or distributed base station into feeders/cells architecture, e.g. horizontal/vertical DAS or star architecture depending on the operator requirements; - Place all the other components like tapper, splitter, centralised switch, base station;

— Connect distributed antennas or base stations to centralised base station/switch via e.g. CAT5 cable, coax or fibre using also tappers, splitters, switches, hubs, amplifiers; - Compute tapper, splitter, BS settings and calculate the loss to each antenna.

19. A computer program product that when executed in a computer performs the method according to claims 1-12.