The present invention relates to a method for setting up a small area radio base station, Femto RBS, in a wireless communications network. More particularly, the present invention relates to a method for selecting a location and power level for the installation of a small area radio base station.
Femto Radio Base Stations (Femto RBSs), also called small area/office Base Stations or Pico Base Stations, are being developed in order to provide GSM and/or WCDMA coverage for end-users in small coverage areas e.g. at home, office, restaurants etc. A Femto BTS is typically connected to a separate Base Station Controller (BSC) or Radio Network Controller (RNC) Femto BSC/RNC.
The Femto RBS is expected to be sold to end users and they can then freely select the location for the Femto RBS in e.g. an apartment. This end user installation procedure makes the base station more of a consumer product requiring some end user interaction.
Coverage is an important aspect of radio access networks. For a Femto RBS in e.g. an apartment the coverage depends on the location of the base station and output power. In a first release of the Femto RBS the output power is estimated to typically be fixed between 0-10 dBm. The fixed output power can be pre-configured in the Femto RBS or selected during an installation procedure wherein the Femto RBS performs a self configuration and setup procedure. This self configuration and setup procedure is controlled by a control node (BSC/RNC).
In patent application publication US2007097939, there are described methods and apparatuses for configuring a Femto RBS. A macro receiver of the Femto RBS is used to acquire detected coverage information of a radio access network (RAN). The detected coverage information is used to determine an operation parameter for use by the macro transceiver of the Femto RBS. In one embodiment, the detected coverage information is transmitted to a control node of the RAN. The control node (BSC/RNC) determines the operation parameter and communicates the operation parameter to the Femto RBS. The Femto RBS is configured accordingly using the operation parameter for further operation towards User Equipments (UEs) accessing the Femto RBS.
A Femto RBS is installed and managed by end users in a plug-and-play manner which creates special needs for such a system and giving operators restricted information and restricted access to Femto RBSs. Problems with existing solutions is when using fixed output power for Femto BTSs it is likely to cause problems in terms of insufficient coverage, too high energy consumption and unnecessary radio transmission. A fixed output power level for Femto BTSs will be too low in some situations (e.g. a large house) which will cause coverage holes and bad end-user experience. The power level can also be too high in other situations (e.g. a small apartment) and this causes unnecessary high energy consumption and transmission which in turn increases the Specific Absorption Rate (SAR) value and generated interference to other base stations. The SAR value indicates an amount of electromagnetic radiation generated from mobile communication terminals and absorbed by humans.
In addition the free selection of the Femto BTS in the house or apartment may not be suitable and cause both insufficient coverage and excessive output power in different parts of the home environment.
Thus, an object of the invention is to provide a solution to optimized location and coverage of Femto Radio Base Stations and a method for installing and selecting a suitable power level.
In an embodiment of the present invention a method is described during which an end user can assist in finding a suitable power level and an appropriate location for a Femto Radio Base Station.
Another embodiment of the present invention is to provide a method for installing an end user controllable radio base station in a wireless communications network. The radio base station is adapted to provide access for the end user of wireless user equipment in the wireless communications network. The radio base station further comprises a display and a power level adjusting equipment. The method is characterized by a first step of connecting the radio base station to the wireless communications network. A second step is to activate a self configuration procedure of the radio base station. As a third step the display on the radio base station further displays instructions to the end user as part of the installation procedure. These instructions comprise a request for wireless user equipment activity. The activity of the wireless equipment is monitored, and the power level is adjusted, if needed, as a following step as part of completing the installation.
In yet another embodiment of the present invention there is provided a radio base station (RBS) adapted to provide access to an end user of wireless user equipment (UE). The UE is within a requested coverage area of a wireless communications network. The radio base station comprises connection equipments that are used to connect the radio base station to the wireless communications network. Activation equipment is included in the radio base station for activating a self configuration procedure of the radio base station. Also, the radio base station comprises a display that is used to display instructions to the end user as part of an installation procedure. These instructions comprise a request for wireless user equipment activity. The radio base station further comprises a monitor that is used to monitor activity of the wireless user equipment. A power level adjusting equipment is used in the radio base station in order to adjust the power level, if needed, as to complete the installation.
It will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departure from the scope thereof, which is defined by the appended claims.
A purpose of the present invention is to enable optimized selection of location and power of a Femto RBS in a home environment, office or small coverage area.
A solution is to provide a procedure during which an end user can assist in finding a suitable power level and an appropriate location for setting up a Femto RBS by means of a display and power level adjusting equipment on the Femto RBS. The power level adjusting equipment may be software in the RBS and/or a regulator reachable for the end user. An example method for finding the suitable power level and the appropriate location of the Femto RBS is described by
As an example the invention details how an end user initiates an installation procedure by pressing a button on the Femto RBS. The procedure includes monitoring of packet switched (PS) or circuit switched (CS) calls and thereafter selecting an appropriate power level, automatically or manually executed power level regulation, or determining if a current location of the Femto RBS is appropriate. There is also the possibility of indicating a current coverage level on a display and how this coverage level could be improved by moving the Femto RBS to a new location within a home environment and following the instructions on the display. The instructions as for example: make one or more calls from the wireless user equipment while moving around in a requested coverage area; turn your laptop on and start downloading files while moving in a requested coverage area etc.
Mentioned above,
1. The end user typically places the Femto RBS over an entry door at a house or connects the Femto RBS directly to an IP network. If the Femto RBS is not directly connected to the IP network then it might be connect through another access point. The end user can therefore freely choose the location of the Femto RBS and set up a wireless connection to for example a wireless router.
2. A self configuration is automatically or manually activated. This procedure may or may not involve the BSC/RNC and/or the OSS participating in the self configuration. At this point a Femto RBS is functional and can be used to make phone calls, establish data connections etc. The output power level can e.g. be selected based on pre-configuration in the Femto RBS or by command from the control node (BSC/RNC).
3. The end user initiates an installation procedure by for example pressing a display button or making a call. The display on the Femto RBS starts displaying instructions to the end user as part of the installation procedure. These instructions to the end user comprise recommendation (order) for performing one or more calls from the wireless user equipment while moving between different locations in an intended coverage area. The instructions may also include manual regulations of the power level, if needed. Typically the power level adjustments are performed by the RBS without any interference from any other node. As an alternative the display on the Femto RBS may instruct the end user to perform a single phone call and to walk around in a requested coverage area where the Femto RBS is intended to provide coverage. During the installation procedure the Femto RBS would typically use highest possible power level as a default level.
4. The end user performs one or multiple phone calls using a wireless user equipment (UE) at different locations in a requested coverage area (home environment) where the Femto RBS shall or is intended to provide services.
5. The Femto RBS monitors the radio quality during the phone call(s). This can be e.g. received signal level (RxLev) on Down Link (DL) and/or Up Link (UL) and/or received quality (RxQual) on DL and UL. The DL measurements are typically obtained from Measurement Reports sent from the UE. Other types of measurements are also possible.
6. The Femto RBS concludes a most appropriate power level based on monitored radio quality during the phone calls. This would typically be a lowest possible power level while still providing full coverage. As an example, if a received signal level is 3 dB higher than required to provide full coverage then a concluded power level can be 3 dB lower than a power level used during the installation procedure. The concluded power level is then set by the Femto RBS. The end user might regulate the power level himself. Additionally, the power level may or may not be sufficient to provide full coverage at the home environment with the current location of the Femto RBS. Therefore, a new location for set up is recommended on the display, e.g. a recommendation to move the Femto RBS closer to a position where a specific phone call was made during the installation. The installation procedure is thereafter repeated at the new location.
In another preferred embodiment the Femto BTS determines the expected service level (e.g. % of coverage) with a current location of the Femto RBS. This is done as mentioned above, e.g. by monitoring received signal level (RxLev) on DL and UL and received quality (RxQual) on DL and UL. The expected service level can then be displayed to an end user and there can also be an indication to move the Femto RBS closer to a certain position identified by a specific phone call (e.g. “Femto RBS cannot provide full coverage at current location, please move closer to where phone call #3 was made.”). This step can also be performed even if the maximum power level is sufficient to provide full coverage with the current location of the Femto RBS and the benefit would then be the possibility to use lower power in the home environment.
In yet an embodiment of the present invention the RBS 600 might further comprise a regulator 606 making it possible for the end user to manually regulate the power level. The regulation can be based on displayed instructions and/or according to a preferred power level giving a requested radio quality in a requested coverage area. That is an acceptable power level, for the end user, in a requested coverage area e.g. his home or the main part of home, building etc. The end user might have own restriction for a SAR value and therefore is comfortable with low bandwidth or less coverage in order to decrease the power level.
In yet another embodiment of the present invention the method can be part of a program product distributed between control nodes 300 and core network nodes (100, 200) of a wireless communications network 1. The method can also be software stored on a disc downloaded to the RBS 600 as part of the self configuration procedure. The disc is then used by for example a wired or wireless station in the coverage area to execute the method of claims 1-9. The RBS can as well have an entry for a for example USB port wherein software can be initiated.
The invention is not limited to the examples of embodiments described above and shown in the drawings, but may be varied freely within the scope of the appended claims. For example, as has also been pointed out elsewhere in this text, the invention may be applied in a variety of systems which utilize the principle of information reporting between two nodes in the system.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/SE07/50549 | 8/14/2007 | WO | 00 | 2/11/2010 |