FR2955449A1 - Assistance method for positioning e.g. communication device in home-cinema type domestic wireless personal area network, involves providing information relative to quality level of communication between given device and reference device - Google Patents

Abstract

The method involves associating an obtained position of a device to a favorable or unfavorable positioning state. Information relative to a quality level of communication between the given device and a reference device is obtained (1007) if the associated state is favorable. The information relative to the quality level of communication between the given device and the reference device is provided (1008). Information relative to another quality level of communication between the given device and a reference device is provided (1012) if the associated state is unfavorable. Independent claims are also included for the following: (1) a computer program product comprising a set of instructions for implementing a method for assistance in positioning of a given device in a wireless telecommunication network (2) a storage unit for storing the computer program (3) a device for assistance in positioning of a given device in a wireless telecommunication network.

Description

Method of assisting the positioning of a device in a wireless communication network, computer program product, storage means and corresponding device. FIELD OF THE INVENTION The field of the invention is that of wireless communication networks, such as, for example, home wireless communication networks using the 60 GHz radio band. More specifically, the invention relates to a technique for assisting the positioning of a communication device in a wireless network. 2. BACKGROUND TECHNOLOGY Personal networks or PANs (for "Personal Area Networks" in English) can be wired (as is the case for USB networks or IEEE 1394) but can also be used on the use of a wireless medium. This is called personal wireless network (or WPAN network for "Wireless Personal Area Networks" in English). The IEEE 802.15.1, UWB, ZigBee (IEEE 802.15.4), IEEE 802.11e or IEEE 802.15.3 Bluetooth standards are among the most used protocols for this type of network. Personal wireless networks currently use a wide range of transmission frequencies, typically between 2.4 GHz and 60 GHz. Personal wireless networks using the 60GHz frequency band are particularly well suited for high-speed data transmission in a limited radius, for example as a means of connectivity between the different elements of a home cinema-type communication network. . Such a system comprises for example different audio video sources (Blu-Ray player, high definition digital video camera, laptop, multimedia hard disk, satellite receiver / IP TV ...), several speakers and a high video display system. definition (video projection, flat screen, ...) including a second video display system such as the screen of a laptop. In a personal wireless network using the 60GHz frequency band, the use of transmit and receive antennas can also play a crucial role in the quality of communication.

An isotropic antenna is a radiating antenna with the same physical characteristics in all directions of space. A selective antenna is an antenna whose radiated energy is voluntarily distributed unequally in space. Certain directions are favored in order to obtain a better gain. This is called "radiation lobes". An antenna radiation pattern is used to visualize these radiation lobes in at least two of the three directions of space. The use of antenna array ("antenna array") associated with the beam forming technique ensures the quality of communication in a personal wireless network at 60GHz. The beamforming technique makes it possible to electronically control an antenna array in reception and / or transmission in order to obtain a beam (or set of beams) for reception and / or directional transmission and more or less narrow. Thus, when receiving a radio signal, this technique makes it possible to increase the sensitivity of the receiver device in at least one desired direction and to reduce the sensitivity of the antenna for interference or highly noisy areas. When transmitting a radio signal, this technique increases the power of the radio signal in one or more desired direction (s). In the remainder of this document, an array of antennas associated with the beamforming technique will be designated by programmable antenna. Networks using the 60GHz radio band have a high sensitivity to the phenomena of interference and masking of radio communication links. In the context of a static configuration of a home network, these phenomena can be caused by the presence of disturbing objects such as furniture, plants for example, or by the presence of living beings within the zone of coverage of the home network. At a given moment, the network is made up of a set of devices and a new device must be inserted into the existing network (for example when a new speaker or a digital video camera is turned on, or looking to connect a laptop).

Consequently, in order to be able to position a communication device within such a network under the best possible communication conditions, it is necessary to take account of these disruptive objects of network communications. Indeed, an object, such as a sofa or furniture, located on an axis of communication between this device and another device of the network would probably not allow them to communicate with a sufficient level of communication quality. Thus, for such a location within the network, the device to be positioned will not be able to benefit the network resources to the best advantage. Furthermore, when positioning a communication device, it is also important to take into account possible disturbances that this device could cause on network communications because of its presence in the network communication coverage area. It therefore appears particularly interesting to be able to propose to a user of a home network, a diagnosis relating to the quality of positioning of a communication device in this network, so that it can better adjust its location so that the The device optimizes network resources without disrupting their operation and allows them to transmit their application data with the best possible level of service. A known technique, disclosed in US patent application US 2009/0005061, provides a service level display system associated with the position of a mobile device in a wireless communication network. More particularly, after determining the position of the mobile device by means of a triangulation or GPS localization mechanism, the latter is compared to a set of predefined service areas in the network, each service area comprising applications that can to be allowed to him or not. If the mobile device is in a service area in which at least one application can be provided, a user interface then informs the user of the accessibility of that application. However, this known technique does not provide a solution for assisting the positioning of a communication device in a network so that it can improve its level of service. This known technique only makes it possible to provide an indication to the user on the availability or otherwise of application (s) in the area where the communication device is located. Thus, even if the device is in an area of the network allowing it to benefit from the availability of one or more applications, it is possible that the level of service is not optimal or even insufficient in the end. Indeed, this known technique provides no way to qualify the level of service, let alone means to improve when necessary. OBJECTIVES OF THE INVENTION The invention, in at least one embodiment, has the particular objective of overcoming these various disadvantages of the state of the art. More specifically, in at least one embodiment of the invention, an objective is to provide a technique for assisting the positioning of a communication device in a wireless communication network. At least one embodiment of the invention also aims to provide such a technique that can provide a network user with a diagnosis of positioning quality of the device to be positioned, so that it can judge the need to reposition it in an area of the network where: - accessibility to network resources is better; the presence of the device does not disturb the operation of the network in terms of communication. At least one embodiment of the invention also aims to provide such a technique that improves the communication quality level of the latter with at least one other network communication device. In other words, at least one embodiment of the invention aims to provide such a technique that makes it possible to inform the user of the level of communication quality of the device that he can expect at this position for a certain time. subsequent transmission of application data, so that it can possibly move the device if this level of communication quality is insufficient. A further object of at least one embodiment of the invention is to provide such a technique which relies solely on means conventionally used for data transmission in a wireless communication network, i.e. say a technique that is simple to implement and inexpensive. 4. DISCLOSURE OF THE INVENTION In a particular embodiment of the invention, there is provided a method of assisting the positioning of a given device in a wireless communication network comprising a plurality of communication devices, said method comprising steps of: - obtaining the position of the given device; associating the position obtained of the given device with a positioning state, favorable or unfavorable, according to a first predetermined rule; if the state associated with the position obtained from the given device is favorable: obtain information relating to a level of quality of communication between the given device and at least one reference device, each reference device being determined according to a second rule predetermined; * provide said information relating to a level of communication quality; - if the state associated with the obtained position of the given device is unfavorable: * provide predefined information relating to a first level of communication quality.

Thus, this particular embodiment of the invention is based on a completely new and inventive approach for providing the user (or a machine) with information enabling the user (or the latter) to decide whether or not to modify (and thus refine) the position of the given device within the network, this information being a function of a positioning state of the given device.

If the state associated with the obtained position of the given device is favorable, it is information relating to a level of quality of communication which is provided to the user so that the latter judges the need or not to move the given device. in the network. If the state associated with the obtained position of the given device is unfavorable, predefined information (by default) is provided to the user prompting him to move the given device in the network.

Thus, the communication quality level information provided to a user is not simply dependent on the actual communication quality level. It serves as an incentive for the user to move the given device. Advantageously, the step of associating the obtained position of the given device with a positioning state comprises a step of determining a geographical area in which the position obtained of the given device is located, the associated positioning state corresponding to a given position. positioning quality information associated with said geographical area. Thus, the association between the position of the given device and a positioning state is simplified. It should also be noted that this positioning quality information can be defined according to other criteria, such as, for example, as a function of a distance between the given device and one or more lines of sight between network equipment and / or according to a distance between the incoming device and one or more disturbing obstacles. Preferably, the method first comprises a step of obtaining a representation of a plurality of geographical zones each associated with said positioning quality information. It is therefore possible to determine the state associated with the position obtained from the given device using a map comprising a plurality of geographical areas, each being associated with information relating to the quality of positioning that the given device would have. assuming that it is positioned in this geographic area of the network. Thus, it is possible to predefine the association between zones and positioning quality information and thus define areas that for example a user can program. Such a user can for example define a zone with an unfavorable positioning state, without this being linked to a poor quality of reception of communication signals in this zone, but because this zone is a reputedly busy zone (many moving obstacles are considered in this area, which could cause disruption in communications with the given device). Another positioning of the given device is then desirable. Note that this representation space can for example be defined by a user of the communication network (such as a home network) by means of a human machine interface or by the communication network itself. According to an advantageous characteristic, according to said second predetermined rule, each reference device is a communication device such that no geographical zone, associated with positioning quality information corresponding to the unfavorable state, is situated between the reference device and the given device. In this way, the user is assured, when he has to move the incoming device to adjust its position in the network (following the communication quality level indications provided), that the given device does not fit into the network. a geographical zone whose associated positioning quality information corresponds to a state of unfavorable positioning. In other words, the present invention provides that there is no interference between a geographical area whose state associated with the position obtained from the given device in this area is unfavorable and a communication between the given device and one or several reference devices. In addition, this allows when the unfavorable area is for example a deemed busy area (as already mentioned above) to ensure that the communications between the given device and the reference device will not be subject to interference related to this unfavorable area. The user is then prompted to move the given device in a direction other than the said adverse zone. Advantageously, if the state associated with the position obtained from the given device is favorable, it comprises a step of providing predefined information relating to a second level of communication quality. If the state associated with the obtained position of the given device is favorable, the user can be informed by means of an indicator that can take the form of, for example, a green light emitting diode. Advantageously, the second level of communication quality is strictly superior to the first level of communication quality. Thus, the user is encouraged to keep the positioning of the given device in a zone defined as favorable, regardless of the level of effective communication quality in the favorable zone considered and that in the adverse zone considered. Advantageously, the first level of default communication quality is representative of a state where no communication is possible between the given device and the plurality of communication devices of the network (although in the present state of communications actually seem possible between the given device and network devices). If the state associated with the obtained position of the given device is unfavorable, the user can be informed by means of an indicator which can take the form, for example, of a red light emitting diode, thus prompting him to move the given device. According to a preferred characteristic, according to said first predetermined rule, the positioning state is favorable if, assuming that a communication device is placed in a geographical area in which the position of the given device would be obtained, the following two favorable criteria are respected: - a communication quality level, between the device placed in said zone and at least one of said other communication devices, is greater than a predetermined communication quality threshold; and a level of disturbance of said network by said device placed in said zone is less than a predetermined disturbance threshold; and, according to said first predetermined rule, the positioning state is unfavorable if, assuming that a communication device is placed in said zone, at least one of the two favorable criteria is not respected. Thus, for a geographical area to be associated with information of positioning quality having a favorable state, two criteria must be respected. The first criterion is based on the fact that the communication quality between a communication device (assuming that it is placed in this area) and other communication devices must be of a sufficiently high level. Indeed, the communication device placed in this geographical area must be able to communicate with other devices of the network with a sufficient level of quality, to be able to benefit from the resources of the network for example.

The second criterion is based on the fact that the communication device (assuming that the latter is placed in this zone), by its presence, must not cause any disturbance to the operation of the network beyond a certain level of disturbance.

If at least one of the two criteria is not met, the positioning quality information then has the unfavorable state. Information relating to a level of communication quality can not therefore be obtained if a geographical area associated with such information (unfavorable state) is placed between the given device and a reference device. Indeed, the present invention provides that there is no interference between a geographical area whose state is unfavorable and a communication between the given device and one or more reference devices. Advantageously, the method comprises a step of associating the obtained position of the given device with a neutral positioning state if said obtained position of the given device has been associated neither with the favorable positioning state nor with the unfavorable state. and the method comprises the same steps if the state associated with the obtained position of the given device is the favorable state or the neutral state. Thus, if the positioning quality information takes neither the favorable state nor the unfavorable state (in the case where a geographical zone is not associated with any favorable or unfavorable criterion for example), the steps of the method are nevertheless realized. In this case, it is considered that, even if none of the favorable and unfavorable criteria can be verified, it is possible for the device to be in a geographical area enabling it to communicate sufficiently with the devices of the network, and without disrupt the network. This forces the method to determine the information relating to the level of communication quality of the device which is then provided to the user so that it judges by itself if the given device deserves or not to be moved. According to an alternative embodiment, the method comprises a step of associating the obtained position of the given device with a neutral positioning state if said obtained position of the given device has been associated neither with the favorable positioning state nor with the unfavorable state, and the method comprises the same steps if the state associated with the obtained position of the given device is the unfavorable state or the neutral state.

Thus, if the positioning quality information takes neither the favorable state nor the unfavorable state, the steps of the method are not implemented. In this variant, considering that there is a non-zero risk that the device may be in a geographical area that does not allow it to communicate sufficiently with the network devices or a geographical area in which its presence causes (or may cause ) a high level of disturbances on the network (even if none of the favorable and unfavorable criteria can be verified), it is preferred to stop the process. According to an advantageous characteristic, said information relating to a communication quality level is explicit information corresponding to a signal power level received during said communication. Such information makes it possible to encourage the user to move the given device in the network in the case where the level of quality of communication provided does not seem to him sufficient for example.

Advantageously, said step of obtaining the position of the given device comprises the steps of: for at least two communication devices, determining a line of sight angle with respect to the given device, between a predetermined reference axis and an axis estimated line of sight between the communication device and the given device; determining the position of the given device according to said determined line of sight angles. By simple measurements of line of sight angles with respect to the given device, it is possible to estimate its position within the network. Line-of-sight angles can be estimated using measurements of the communication quality level between each of the communication devices involved in the location of the given device and the given device, for example by scanning the receiving antenna on the entire angular spectrum that it covers while the transmitting antenna is isotropically configured.

Advantageously, the communication network comprises a set of pairs consisting of a transmitting device and a receiving device, each of the devices having a determined communication coverage area, the coverage areas of each pair having a region of mutual intersection, at least one of the said favorable criteria is related to a given number of disturbed mutual intersection zone (s) for a considered geographical zone, a disturbed mutual intersection zone presenting a given disturbance state according to a criterion determined the communication quality between the devices of the pairs corresponding to said disturbed mutual intersection zone. The relevance of the criteria for determining the positioning status of the given device in the coverage area of the network is therefore improved. By way of nonlimiting example, it is possible to consider that an area associated with information of positioning quality corresponding to: the favorable state, is an area containing no disturbed mutual intersection zone of coverage for a pair of transmitter / receiver devices; the neutral state is an area containing a disturbed mutual intersection zone; - the unfavorable state, is an area containing two or more. In another embodiment of the invention there is provided a computer program product comprising program code instructions for carrying out the aforesaid method (in any one of its various embodiments), when said program is run on a computer. In another embodiment of the invention, there is provided a computer readable storage means storing a computer program comprising a set of computer executable instructions for carrying out the aforesaid method (in any one of of its different embodiments).

In another embodiment of the invention, there is provided a device for assisting the positioning of a given device in a wireless communication network comprising a plurality of communication devices, said positioning assistance device. comprising: - means for obtaining the position of the given device; means for associating the position obtained of the given device with a positioning state, favorable or unfavorable, according to a first predetermined rule; means, activated if the state associated with the position obtained from the given device is favorable: to obtain information relating to a level of quality of communication between the given device and at least one reference device, each reference device being determined according to a second predetermined rule; * to provide said information relating to a level of communication quality; - Means, activated if the state associated with the obtained position of the given device is unfavorable, to provide a predefined information relating to a first level of communication quality. Advantageously, the positioning assistance device comprises means for implementing the steps of the positioning assistance method as described above, in any one of its various embodiments. 5. LIST OF FIGURES Other features and advantages of the invention will appear on reading the following description, given by way of indicative and nonlimiting example, and the appended drawings, in which: FIG. example of access to a communication medium according to a time division multiple access protocol (TDMA); - Figure 2 shows the schematic structure of a communication device 25 implementing the positioning assistance method, according to a particular embodiment according to the invention; FIG. 3 presents a flow diagram of an algorithm for locating an incoming communication device according to a particular embodiment of the invention; FIG. 4 illustrates a communication scheme in which a method of locating an incoming device with respect to two other devices of the network is implemented, according to a particular embodiment of the invention. FIG. 5 presents a flow chart of an algorithm for determining, by an incoming device equipped with a programmable antenna, line-of-sight angles with respect to other devices of the network, according to a particular embodiment of FIG. invention; FIG. 6 illustrates an exemplary map of geographical zones of the network, according to a particular embodiment of the invention; FIG. 7 shows an example of a storage table of a map of geographical zones as illustrated in FIG. 6; FIG. 8 presents a flowchart of an algorithm for comparing the position of an incoming device with a map of geographical areas of the network, according to a particular embodiment of the invention; FIG. 9 presents a flowchart of a network device selection algorithm that can be used as a reference for testing the level of quality of communication with the incoming device, according to a particular embodiment of the invention; FIG. 10 presents a flowchart of an implementation algorithm of the positioning assistance method, according to a particular embodiment of the invention; FIG. 11a illustrates an exemplary structure of an insertion request, FIG. 11b, an exemplary structure of an acknowledgment message, and FIG. 11c, an exemplary structure of a location pattern message. ; FIG. 12 illustrates a schematic example of a coverage intersection zone for a pair of transmitter / receiver devices in a communication network, according to a particular embodiment of the invention; FIG. 13a illustrates a schematic example of a recovery zone in a wireless communication network according to a particular embodiment of the invention; FIG. 13b schematically illustrates a method for determining an overlap zone, based on a Weiler-Atherton polygon intersection algorithm; FIG. 14 illustrates the structure of a notification message of the state of disturbance of the intersection zone of covers; FIG. 15 presents a flow chart of an algorithm for locating disturbance zones according to a particular embodiment of the invention. DETAILED DESCRIPTION FIG. 1 illustrates an example of access to a communication medium according to a time division multiple access protocol or TDMA protocol (for "Time Division Medium Access"). This is a time multiplexing for the control of access to the medium wireless (or MAC for "Medium Access Control" in English) whose principle is based on a division of the time domain into a plurality of cycles transmission network (More commonly referred to as "superframe cycles" or "superframe cycles" in English), each superframe cycle being divided into a plurality of time slots (called "time slots" in English), which are allocated successively to different network devices. Each device of the network can therefore in turn transmit data on the same radio communication channel, the other devices then being either in an operating mode for receiving the data, or in another mode of operation that does not disturb the communication channel. radio, such as in standby mode. Conventionally, each superframe cycle comprises a first predefined transmission sequence 100, called the first superframe period or SFP1 period (for "first SuperFrame Period" in English), reserved for the transmission of data of a first type (c '). that is, low bit rate data such as control data, for example), and a second predefined transmission sequence 101, called the second super frame period or SFP2 period (for "second Super Frame Period"), reserved for the transmission of data of a second type (that is to say high or very high speed data, such as audio data, video, or more generally application data). For example, the SFP1 period corresponds to 15% of the duration of a superframe cycle, and the SFP2 period to 85% of the duration of a superframe cycle. During the SFP1 period in the superframe cycle, the devices each transmit a radio data frame 110, 111, 112, 113, 114, 115, in turn.

Each data frame comprises: a preamble 102, intended for the synchronization of the receiving devices of the network during the reception of a data frame; a MAC 103 header field for transmitting data relating to access control to the wireless medium. This field more precisely describes a given sequence of time intervals of the superframe cycle. Access to the network during a superframe cycle is therefore defined by this given sequence, the devices communicating according to this sequence, which in particular makes it possible to avoid collision problems; and a payload field 104 for low level data transmission if the data frame in question is transmitted during the SFP1 or high-level period if the data frame is transmitted during the SFP2 period. . A minimum guard interval is required between each data frame transmission 110, 111, 112, 113, 114, 115.

Each device sends a frame during each SFP1 period, even if it has no useful data to transmit (it then uses padding data in English) .This allows the information contained in the MAC header to be relayed, and to incoming devices equipped with a programmable antenna to determine line of sight angles (described below in connection with Figure 5).

During the SFP2 period in the superframe cycle, the data frames 120 to 121 are transmitted one after the other, these data frames 120 to 121 being able to have a format identical to that of the frames 110, 111, 112 , 113, 114, 115 transmitted during the SFP1 period. Between the transmission of the last data frame 115 of the SFP1 period and the transmission of the first data frame 120 of the SFP2 period, there is found a contention period 150 or CS period (for "contention slot" in English), followed by a period of custody. This period CS 150 is not used in transmission by the devices of the network, it allows a communication device entering the network, to transmit an insertion request (also called access request in French or "join request" in English) to register with other devices in the network. According to a particular embodiment, this insertion request, the structure of which is detailed below in relation to FIG. 1a, can be processed by a specific device of the network, such as a central device, which then takes care of allocate to the incoming device a transmission time slot within the network. This transmission time interval can be taken over the period CS 150, which then sees its duration decrease with the increase in the number of network devices inserted. According to an alternative embodiment, the processing of this insertion request can be performed in a distributed manner, that is to say by the different devices of the network.

The incoming device then takes cognizance of the position of the time slot assigned to it in the sequence of superframe cycle time slots, by analyzing the contents of the MAC header field 103 of the data frame (s). received from the network device (s). The schematic structure of a communication device 200 embodying the positioning assistance method according to a particular embodiment in accordance with the invention is now presented with reference to FIG. 2. The communication device 200 comprises: a random access memory (Random Access Memory) 202 operating as a main memory; a calculation block 201 (noted μc for "micro-controller" in English) or CPU (for "Control Process Unit" in English) whose capacity can be extended by an optional RAM connected to an expansion port ( not shown in Figure 2). The CPU 201 is able to execute instructions when the communication device 200 is turned on from the ROM 203. After the power is turned on, the CPU 201 is able to execute the RAM 202 relating to a computer program, once these instructions are loaded from the ROM 203 or from an external memory (not shown in FIG. 2). Such a computer program, if executed by the CPU 201, causes the execution of at least a part of the steps of the algorithms described below in relation to FIGS. 3, 5, 8, 9 and 10; a block 205 (denoted RF-FE for RF "Front-End" in English) responsible for the adaptation of the signal at the output of a baseband block 206 (noted BB for "Base-Band" in English) before its transmission by means of an antenna 204. By way of example, the adaptation can be carried out by frequency conversion and power amplification processes. Conversely, the block 205 also allows the adaptation of a signal received by the antenna 204 before its transmission to the baseband block 206. The baseband block 206 is responsible for modulating and demodulating the digital data exchanged with the baseband 206. block 205; an input / output interface block (denoted I / O If for "Input / Output Interface" in English) 211 connected to a communication network 212; a user interface block (noted U If for "User Interface" in English) 207 in charge of the interaction with the user using for example a series of light-emitting diodes. This interface block 207 makes it possible to provide the user with an indication of: * the general state of the device (stop, operation in progress); the state (or quality) of positioning of the incoming device, according to the principle described below in relation to FIG. 8; the level of quality of communication (or level of quality of service) between the incoming device and at least one other device of the network, according to the principle described below in connection with FIG. 9; a service interface block (denoted S If for "Service Interface" in English) 208, in the form of a communication interface of USB or Ethernet type. This interface block 208 is used to set up certain functions such as those making it possible to obtain a map of geographical areas of the network (if it is created or updated on an external computer for example) and the coordinates of the position of the network. device entering the network. An example of a map of geographical areas is illustrated below in relation with FIG. 6. FIG. 3 presents a flowchart of an algorithm for locating an incoming communication device provided with a simple antenna according to a particular embodiment of FIG. the invention. Upon initialization of the location algorithm in step 300, a number of network devices (hereinafter referred to as "locator devices") locate the incoming device. Knowing the position of the transmission time slot of the incoming device (information contained in the MAC header field 103 of the data frames), each locating device then proceeds to a scan of its antenna (programmable) in reception, for example in a predetermined angular sector, in order to detect a radio frame having a specific, predetermined format for performing a measurement of the relative position of the transmitter. This radio frame is called a "radio location frame" in step 301. The location radio frame (the structure of which is detailed below in connection with FIG. 11c) is a predetermined signal. known from the other devices of the network, which is transmitted by the incoming device to trigger a localization phase of the device entering by the devices of the network. Specifically, the transmission of a location radio frame can be performed successively in the course of several superframes, thereby defining the duration of the localization phase of the incoming device. For example, a location radio frame sent in the course of 20 consecutive superframes makes it possible to obtain, at a rate of lms per superframe, a localization phase duration equal to 20 ms. As an illustrative example, the receiving antenna scan is performed according to a set of antenna orientation angles that can take any angle value, in steps of 5 degrees, in an angular sector between 0 degrees. and 180 degrees. Thus, for each antenna orientation angle, the locator device measures the power level upon reception of the signal (i.e., the received location radio frame) during step 302.

If the predetermined angular sector of the receiving antenna of the locating device has not been fully traversed during the transmission time interval of the incoming device, it waits for the transmission time interval of the next superframe to continue. the scanning of its antenna and make new measurements of the power level in reception. When the predetermined angular sector of the receiving antenna of the locating device has been completely traversed, then only the antenna orientation angle, for which the highest estimated level of power reception (among the set of measurements realized power) is greater than a predetermined threshold, is retained for calculating the position of the device entering the network. This is called an estimated line of sight angle with respect to the incoming device, the latter allowing the establishment of direct line of sight of a communication link with the incoming device. In the remainder of the description, it is considered that a "line of sight angle" is an antenna orientation angle formed by, on the one hand, a predefined reference axis and, on the other hand, an axis an estimate of line of sight between the locating device and the incoming device making it possible to establish, with a sufficient level of communication quality, a communication link between these devices. Step 303 makes it possible to test whether the locator device involved in the locating phase is the central device (also called the management device) or not. If this is the case, the algorithm goes to step 304, otherwise it goes to step 307. Of course, this test 303 is not performed in the case where the role (central or not) of the device locator is predefined. In this case, steps 304 or 307 are executed directly. In step 304, the central device is responsible for centralizing all the line of sight angle values estimated by the different network locator devices involved in the localization phase of the incoming device. In the case where a locating device obtains no line of sight angle with respect to the incoming device (for example due to the presence of an obstacle situated between the two devices), or in the case where the angle found does not does not correspond to a power level higher than the predetermined threshold, it transmits to the central device a message containing the status "no valid angle".

Once the set of view line angle values received by the central device, the latter then takes charge of estimating in step 305 (detailed below in relation to FIG. 4) the position of the incoming device. in the coverage area of the network, then transmits this information to the device entering at step 306. In step 307, the locator device transmits, during its own transmission time interval, the value of the line of sight that he has estimated (or the message containing the status "no valid angle" if any) to the central device. According to a particular embodiment, if the incoming device is equipped with a programmable antenna (also called "agile antenna" in French or "smart antenna" in English), the latter can also transmit to the central device (via the request of insertion) values of estimated line-of-sight angles with respect to one or more devices in the network. After extracting these angle values from the request at step 308, the central device then advantageously has a larger number of data for computing the position of the incoming device performed at step 306 (particular detailed embodiment) hereinafter in relation to FIG. 5). FIG. 4 shows a communication scheme in which a method of locating an incoming device with respect to two other network devices is implemented, according to a particular embodiment of the invention. Next, the case of a wireless communication network, of the "home theater" type, for example, comprising a plurality of sending and receiving devices, each device being able to behave alternately as a transmitting device and a receiving device and having only one antenna for transmitting and receiving radio data signals. In the context of the present invention, it is considered that the topology of the network, that is to say the relative position of the network devices, is known and defined in an orthonormal frame. In the particular embodiment presented here, the position of the incoming device is determined in this trigonometrically orthonormal frame from the already established position of at least two other network devices.

In this figure, the two devices 400 and 402 are considered to be two communication devices, with programmable antennas, each responsible for determining the line of sight angle with respect to the incoming device 401 to be located. A communication link 406 and a communication link 410 may be established respectively between the devices 400 and 401, via the programmable antenna of the device 400 and between the devices 402 and 401, via the programmable antenna of the device 402. The parameters of FIG. antenna used here for the device 400 allow to obtain an antenna pattern adapted to establish a communication with the incoming device 401. More specifically, the antenna of the device 400 is configured in a narrow beam 404 (in this case directional or selective antenna configuration) and the orientation of the narrow beam 404 is represented at a line of sight angle 405 between, on the one hand, a predefined reference axis 403 passing through the device 400 and, on the other hand, the estimated line of sight line 406 between the devices 400 and 401 for which the power level measured by the device 400 is the highest compared to the incoming device 401 In this figure, the device 400 is considered to be the center of origin of the orthonormal coordinate system whose abscissa axis coincides with the predefined reference axis 403 of the device 400.

The antenna parameters used here for the device 402 make it possible to obtain a narrow beam 409 oriented at a line-of-sight angle between, on the one hand, a predefined reference axis 412 and, on the other hand, the estimated line of sight axis 410 between the devices 402 and 401 for which the power level measured by the device 402 is the highest compared to the incoming device 401.

Since the line of sight angle measurement is obtained relative to its predefined reference axis 412, the latter must determine the angle to be taken into account between its predefined reference axis 412 and the abscissa axis of the orthonormal frame ( axis 407). The following notations are considered: - A1, the angle 413 between the abscissa axis (403) for the device 400 and the line of sight line 417 between the two locating devices 400 and 402; A2, the angle 415 between the abscissa axis (407) for the device 402 and the line of sight axis between the two locating devices 400 and 402; B, the angle 416 between the predefined reference axis 412 of the device 402 and the line of sight axis between the two locating devices 400 and 402. From the relation A2 = 180 + A1, it can be deduced that the searched angel between the predefined reference axis 412 and the abscissa axis 407 is equal to: B-A2 = B-180-A1 Thus, all the locating devices have a common reference for the abscissa axis. The device 402 thus deduces its line of sight angle 408 with respect to the abscissa axis of the orthonormal frame considered. For the incoming device 401, the antenna applies antenna parameters to obtain an isotropic radiation pattern 411 (that is to say omnidirectional or quasi-omnidirectional). From the knowledge of each of the line of sight angles 405 and 408, as well as the coordinates of each of the locator devices 400 and 402 in the orthonormal coordinate system, the central device calculates the equations of straight lines (also hereinafter referred to as equations of line of sight) associated with the line of sight axes 406, 410 and between the locator devices 400, 402 and the incoming device 401 to be located, the intersection of these lines to determine the coordinates of the device entering the network. In general, if at least two devices in the network have been able to make a valid line of sight angle measurement with respect to the incoming device, the central device is thus able to determine the position of the incoming device. In addition, it should be noted that the greater the number of locator devices involved in the localization phase, the more precise and accurate the calculation of the position of the device entering the network. The following notations are considered: X1 and Y1, the coordinates of a locating device in the orthonormal frame considered; - A, the line of sight angle of the locator device (included between the abscissa axis and the estimated line of sight line with the incoming device 401).

We then obtain the following line of sight equation: y = px + b, with p = tan (A); b = Y1 -Xl * tan (A). Briefly below is the calculation of a point of intersection between two lines considered. We now consider two line segments of equations: y = pix + b1 and y = p2x + b2. The coordinates (u, v) of the point of intersection of these two segments then satisfy the following relation: y = pix + bi = pzx + b2, ie (pi - p2) x = b2 + b1.

Finally, we obtain the following relation: x = (b2 + bi) / (pi-P2) Thus, the coordinates of the point of intersection (u, v) are as follows: u = (bi-b2) / (p2 - pi) v = ((pi + p2) * u + bi + b2) / 2 The intersections of these lines make it possible to estimate several probable positions of the device to be located (in the case where more than two locating devices participate in the localization of the device). The position of the device to be located can be determined, for example, by taking the center of a scatter plot representative of all the intersections of the line of sight lines obtained (which amounts to averaging the points of intersection ). If some insertion points are considered to be far from the average of the points, these points can be deleted and the average of the coordinates of the remaining intersection points is calculated to obtain an estimate of the position of the incoming device. If a single line of sight equation, if any, can not be calculated by the central device, the central device is not able to estimate the position of the incoming device. In this case, the user must slightly move the incoming device to allow a new estimate of its position in the network. The user can be informed, via the interface block 207, by means of a light emitting diode for example whose color is representative of a bad positioning of the incoming device, which encourages him to move it.

FIG. 5 presents a flow diagram of an algorithm for determining, by an incoming device equipped with a programmable antenna, viewing line angles with respect to other devices of the network, according to a particular embodiment of the invention. .

This algorithm allows more precisely to obtain additional line of sight angle measurements to specify the calculation of the position of the incoming device, provided that it includes a programmable antenna. After reading the information contained in the MAC header field 103 of the data frames that it receives during the period SFP1, the incoming device is able, in step 500, to determine the position of the contention period. CS in the sequence of transmission time slots, as well as its duration, allowing it to transmit the insertion request in order to register with the other devices of the network. It is therefore also able to know the number of devices present in the communication network and the transmission time slot assigned to them in the sequence. In step 501, a device of the network is selected from the set of devices present in the network. In step 502, the incoming device performs a receive antenna scan in a directional antenna pattern in a predetermined antenna sector, to determine a line of sight angle with respect to the selected device (allowing establishing a communication with a sufficient level of communication quality). It should be noted that it is sufficient that the selected device transmits a radio signal so that the incoming device can perform a line of sight angle measurement with respect to the selected device. Each device transmitting a frame during each period SFP1 (according to the principle explained above in relation to Figure 1), this condition is validated. The next step 503 makes it possible to test whether all the devices of the network have been processed.

If so, then step 504 is taken where the incoming device inserts the view-line angle values estimated by it into the selected network devices, as well as the receive power level. associated with each line of sight angle value, in the insertion request that will be issued during the contention period CS. If this is not the case, then step 501 is used to select a new device of the network not yet processed. FIG. 6 illustrates an example of a map of geographical zones of a communication network, according to a particular embodiment of the invention. This card is a representation space of a communication network (of the "home cinema 7.1" type for example) comprising a plurality of geographical areas, each of these geographical areas being associated with information relating to the quality of positioning that would have a communication device assuming that it is positioned in this geographical area of the network. Each geographical area is identified in order to know if the positioning of a communication device (such as the incoming device) in this geographical area would allow it to communicate under sufficient conditions of communication with other devices of the network, without its presence interferes with the operation of the network. These geographical areas can be divided into three categories: "favorable zone", "unfavorable zone" and "neutral zone". A zone is said to be "favorable", If the following criteria are met (assuming that a communication device is placed in such a zone): - the device has sufficient communication conditions with one or more other devices (for example, the level of communication quality between the device in the area and at least one other device in the network is greater than a predetermined communication quality threshold, which predetermined quality threshold can be realized by a lower received power attenuation level; at 3dB with respect to a predefined nominal power); this is the case for example when many devices in the network can communicate with the device placed in the geographical area considered, because no obstacle is present between these devices of the network and said geographical area considered; and the device, by its presence, generates little, if any, disturbances in the operation of the network (for example, the level of disturbance of the network is below a predetermined disturbance threshold, the level of disturbance being be defined by the number of calls whose line of sight passes through the geographical area). It is said that the positioning quality information has a favorable positioning state if the two (favorable) criteria mentioned above are respected. - a zone is said to be "unfavorable", Si (assuming that a communication device is placed in such a zone): - the presence of the device creates a potential risk of significant masking for the other devices of the network (that is, ie disturbance of the network); and / or - the device is not able to communicate satisfactorily with the other devices in the network (insufficient potential communication quality level or excessive attenuation); this is the case, for example, if the incoming device is in a frequent passage zone or if numerous disturbing obstacles are present near this geographical zone; In this case, the positioning quality information has an unfavorable positioning state if at least one of the two (unfavorable) criteria mentioned above is respected, in other words if at least one of the two favorable criteria is not respected. An area is called "neutral" when it is neither favorable nor unfavorable. In other words, the neutral zones of the network include all the other geographical areas of the network. In this figure, the elements 610, 611, 650, 620, 630, 640 and 660 represent the devices of the network and the elements 673 and 672 represent furniture for example. The geographical areas 670 and 674 represent examples of unfavorable zones for the positioning of an incoming communication device, because of a significant potential risk of masking the communications (for example between the devices 630 and 660 for the geographic area 674, between devices 630 and 620, devices 660 and 610 and devices 660 and 611 for geographic area 670).

The geographical zone 600 represents an unfavorable zone example for the positioning of an incoming communication device, since it constitutes a zone of frequent passage of human being (s). A device positioned in this geographical area of the network is likely to be strongly disturbed by this frequent passage. Geographical area 671 represents an example of an unfavorable zone for the positioning of an incoming communication device, since a device positioned in this geographical zone would probably cause a masking of the radio transmissions from the devices 610 and 611 to the other devices 620, 640, 660, 630 of the network. The geographical areas 675, 671, 676 and 677 represent examples of favorable zones for the positioning of an incoming communication device, since they enable it to have good communication conditions with the other devices of the network (and thus to make it benefit the best resources of the network), without risk of disrupting the operation of it, nor being himself disturbed by frequent passage of human being (s) for example. It should be noted that the information constituting the geographical area map can be entered by a user of the home network by means of a computer program executed on a computer, or by any other type of human machine interface. This computer being connected for example to the central device of the network, via a service interface 208 (for example of the USB type), it can obtain from this device the coordinates of the positions of the different devices of the network. The computer program is then able to provide the user with a map representing the network, on which the user can add geographical areas (representative of furniture or frequent passage areas for example). All the information entered by the user is then transmitted to the incoming device, in the form of a storage table whose structure is detailed below in relation to FIG. 7, which can in turn share them with the devices of the network. . Some elements of the map of geographical areas can also be determined by the network itself. For example, when a network device observes a significant decrease in the quality level of reception of its communications with another device, it can be deduced that a source of disturbance has appeared between these two devices. It is likely that this same source of disturbance also affects the communications of other devices in the network. Thus, an incoming communication device placed in the immediate vicinity (for example at a distance less than a predefined threshold) of this identified source of disturbance may also see its communications greatly disturbed due to a masking problem, which makes it an unfavorable area for placement of the incoming device. A method for determining network disturbance zones is detailed below in relation to FIGS. 12 to 15.

The map of geographic areas contains more particularly the coordinates of the vertices of the different geographical zones identified in the network. In a first embodiment, the coordinates of the geographical zones (favorable and unfavorable zones) can be provided by the user according to the type of application targeted for the incoming device, as a function of the previously identified disturbance zones. In a second embodiment, the coordinates of each unfavorable geographical area can be automatically defined around the central point of a disturbance zone that has been previously identified (for example using the means described in relation to FIGS. 15). The coordinates (xc, yc) of the central point then correspond to the average of the coordinates of the different vertices of the identified disturbance zone, the coordinates of the vertices of the unfavorable zone being {(xc-u, yc-u), (xc- u, yc + u), (xc + u, yc-u), (xc + u, yc + u)}, with u a number of units used in the orthonormal coordinate system representing a minimal distance from the disturbance zone to from which placed the device is no longer considered in close proximity. In a third embodiment, the coordinates of each unfavorable geographical area can be automatically defined by searching for the overlapping areas (as defined in relation with FIG. 13a). It is then possible to consider that a favorable zone is a zone containing no coverage intersection zone (radio) for a pair of transmitter / receiver devices (as described with reference to FIG. 12); that a neutral zone contains such a coverage intersection zone and an unfavorable zone contains two or more thereof. Other transition thresholds between favorable, neutral and unfavorable zone definitions are of course applicable. In a fourth embodiment, all the areas not automatically classified as unfavorable by the above means can be classified favorable by default, pending additional information provided by the user. It should be noted that this figure presents a purely illustrative example of map of geographic areas of the network. It is clear, however, that any other policy of defining geographical areas of the network can also be used without departing from the scope of the present invention. FIG. 7 shows an example of a storage table of a map of geographical zones as illustrated in FIG. 6. Such a storage table more particularly comprises: a field Nb 700 zones containing the number of geographical zones included in the map (and thus in the storage table), - Zone fields #n 701, 702, 703 description of the geographical areas included in the map. Each description field 701, 702, 703 itself comprises a set of parameters structured in the following manner: a zone field id 704 containing the identifier of the geographical zone considered; a Coord 705 coordinates field containing all the coordinates of the vertices delimiting the geographical zone considered; a Level 706 field containing information relating to the level of positioning quality attributed to the geographical area in question. This field may for example take the value 0 if the geographical area is favorable, the value 1 if the geographical area is neutral, or the value 2 if the geographical area is unfavorable.

The field 705 more particularly comprises a field Nb vertices 708 containing the number of vertices, followed by as many vertex fields #n 709, 710 as vertices defined in the field 708 each containing the coordinates of the vertex considered. FIG. 8 shows a flowchart of an algorithm for comparing the position of an incoming device with a map of geographical areas of the network, according to a particular embodiment of the invention. By comparing the position of the incoming device, as determined in step 306 of FIG. 3, with the different geographical zones (favorable, unfavorable or neutral) identified in the network, this algorithm aims to determine the positioning quality information which must be associated with the incoming device according to the geographical area of the network in which it is located. This comparison algorithm is based on a method called "half-line algorithm" (or "half-line algorithm" in English). It should be noted that this algorithm of the half-line is well known to those skilled in the art, its elementary principles being recalled below, without attaching to possible optimizations, they are also well known to those skilled in the art. Consider a point P which one wishes to determine if it is inside a polygon Q (that is to say of a geographical zone of the network). The steps of the half-line algorithm are as follows: - from the point P, draw a half-line in any direction (here, we can consider, as an example, a horizontal half-line d 'increasing abscissa) such that none of the vertices of the polygon Q belong to this half-line. - initialize an intersection counter to zero; - for each side of the polygon Q, determine if it has an intersection with the half-line considered, and if so, increment the intersection counter; - Once all sides of the polygon Q have been considered, check the final value of the intersection counter, and if (and only if) the final value is odd, then the point P is inside the polygon Q. Thus, for each geographical area of the map, this half-line method is used to determine whether or not the position of the incoming device is included in the geographical area. To do this, in step 800, an identified geographic area of the geographical area map is selected and, in step 801, a comparison is made between the position of the determined incoming device and the selected area by applying the method of the half-right. In step 802, if the incoming device is included in the selected area, then step 804 is executed and the positioning quality information of the selected area is associated with the incoming device. The positioning quality information associated with the device is therefore that of the zone (whose state may be favorable, neutral or unfavorable), as specified in the field 706 corresponding to the selected zone. If the incoming device is not included in the selected area, then step 808 is executed to determine whether all the geographic areas identified in the map of geographical areas have been compared with the position of the incoming device. If this is not the case, then we return to step 800 to test a next geographical area contained in the map of the geographical areas.

If this is the case, then we go to step 809 where the positioning quality information that is associated with the incoming device has the neutral state, since all the geographical areas not classified as favorable or unfavorable are considered as being neutral by default. In another embodiment, the positioning quality information associated with the incoming device may not be determined with respect to a geographic area, but relative to: • a distance between the incoming device and the disturbance causing obstacle the closer (the obstacles are detected and located by the means described in relation to FIG. 12), and / or • at a distance between the incoming device and the line of sight between the equipment of the nearest network (or even the intersection of several lines of sight between equipment of the network, lines of sight determined as described in relation with Figure 4). The positioning quality information associated with the incoming device can take the favorable state if the previously determined distance is greater (or equal) to a first predetermined threshold value D1, unfavorable if the previously determined distance is less than (or equal to) a second predetermined threshold value D2, or neutral if this distance is between D1 and D2. It is recalled that the distance between a point of coordinates (Xl, Yl) and a segment whose equation is classically of the type y = ax + b (where a is the slope and b the intercept at the origin of the straight line coinciding with the segment) is given by: D = (Xl (Y l û b) * sin (tan-1 (a))) / a Similarly, the distance between a point of coordinates (Xl, Yl) and a point of coordinates (X2, Y2) is given by the relation: D2 = 1X2uX112 + 1Y2uY1l2 Figure 9 provides a flowchart of a network device selection algorithm that can be used as a reference for testing the level of communication quality with the incoming device. This algorithm makes it possible more particularly to determine a list of one or more network devices, referred to as reference devices, which can serve as a basis for bringing the incoming device closer to it (once positioned in a favorable zone) in order to improve the quality of its devices. radio communications with network devices. First, in step 900, a device is selected from among all the devices of the network that have been able to determine a valid line of sight angle with the incoming device (in other words, having been able to establish a line of sight communication with the incoming device) during the localization phase of the incoming device (according to the location method described above in relation to FIG. 3). Then, at step 901, a geographical zone is selected from among all the unfavorable zones included in the map of the geographical zones of the network. In the next step 902, it is determined whether the selected adverse area is between the selected device and the incoming device. It should be noted that this step can be performed on the basis of a method similar to that of the half-line (used previously in connection with Figure 8). Indeed, if the number of intersections between the polygon representing the unfavorable geographical area of the network and the line segment representing the line of sight axis between the incoming device and the selected device is greater than zero, then this means that this unfavorable area lies between the two devices. Thus, if the test of step 903 is positive (the selected adverse area is between the incoming device and the selected device), step 907 is taken and the selected device is not retained to test the level of the selected device. communication quality. It is therefore not considered to be a reference device.

Otherwise, if the test of step 903 is negative (the selected adverse area is not between the incoming device and the selected device), step 905 is taken and the selected device is retained to test the quality level. Communication. I1 is therefore chosen as a reference device. Then, we look if, for the same selected device, all the unfavorable zones were tested. If this is the case, we go to the next step 907, otherwise, we return to step 901 to select another unfavorable zone included in the map of the geographical areas of the network. Once all the unfavorable zones have been tested for the same device, step 907 is executed in order to test whether all the network devices meeting the above criterion (step 900) have been tested. If this is the case, we go on to the next step 908, otherwise, we return to step 900 to select another device of the network. In step 908, it is examined whether at least one reference device has been selected at the end of all of the above steps. If this is the case, proceed to a step 910; otherwise, go to step 909.

If all the devices of the network selected for the implementation of this algorithm have been rejected (no reference device selected), the one with the lowest bit error rate (BER) the power level in reception (RSSI level for example (for "Received Signal Strength Indication") the highest is then chosen, in step 909, as a reference device.

In step 910, if a single reference device has been selected, the radio communication quality level is defined by the bit error rate or the reception power level estimated by this reference device during the first phase. localization of the incoming device or during an update of the localization phase (according to the principle detailed below in relation to FIG. 10). If several reference devices have been selected, the device with the highest level of communication quality is selected at the end of this algorithm. Other policies for determining the level of communication quality can also be used without departing from the scope of the present invention.

In a first embodiment, the communication quality level may be defined by the sum of the receive power levels measured by a plurality of reference devices. In a second embodiment, a network device is retained as a reference device if there is no line of sight between this network device and the incoming device (that is, S the segment connecting the device). incoming and the considered network device, there is no intersection between the segment S and the segments representing the lines of views between network equipment). In a third embodiment, a network device is retained as a reference device if the distance between a given obstacle and the segment representing the line of sight between this network device and the incoming device (segment S) is greater than a predetermined threshold value. . The reference device may also be selected according to a selection criterion based on a combination of the first, second and third embodiments mentioned above.

A flow chart of an implementation algorithm of the positioning assistance method according to a particular embodiment of the invention is now presented in relation with FIG. This algorithm makes it possible to provide a user of a home network with a diagnosis on the positioning of a device entering this network, so that the latter can best adjust the location of this incoming device (if considers it necessary to do so) in order to allow the subsequent implementation of advanced communication functions under the best possible conditions of communication. The term "advanced communication functions" means all the data relating to the user application services (audio, video, image, home automation commands, file transfer, etc.) interacting with the network and provided by the incoming device. They do not include the control data that is related to the intrinsic operation of the network (connection, insertion request, information relating to the line of sight angle values, location signals, etc.). The initialization of the algorithm in step 1000 corresponds, for example, to the start-up of the incoming device that the user wishes to position within his home network. Once placed in the network, the incoming device performs in step 1001 a scan of its receiving antenna to see if it is capable of receiving one or more frames of data transmitted during the period SFP1 by the other devices of the network . In other words, step 1001 makes it possible to check whether the quality level of communication of the control data with the other devices of the network is sufficient and, where appropriate, determines the sequence of transmission intervals of the network allocated to the devices of the network. In step 1002, the incoming device informs the user, via the interface block 204, that it can connect to the network and thus declare itself to the other devices of the network. By way of example, this indication can be provided to the user by means of a green light emitting diode. In an embodiment corresponding to the case where the incoming device incorporates a programmable antenna, an additional step 1016 is executed between steps 1002 and 1003, according to the principle detailed in relation to FIG. 5 above. During this step, the incoming device determines line of sight angles with respect to all or part of the network devices. These line of sight angle measurements are then integrated into the insertion request for later use by the central device during the execution of step 1004.

By analyzing the information contained in the MAC header field 103 of the frames received by the incoming device, it determines the duration and the position of the contention period CS 150 provided in the period SFP1. At step 1003, it then transmits, during this contention period CS 150, an insertion request (the structure of which is detailed hereinafter with reference to FIG. 11a) making it possible to be detected near the devices of the network.

Thus, once detected, a transmission time interval in the transmission time slot sequence of the SFP1 period is allocated to the incoming device, allowing it to communicate with other devices in the network. Step 1004 consists of determining the position of the device entering the network. To do this, the incoming device uses the transmission time slot which has just been allocated to it to transmit a location radio frame (the principle of which is described above in relation to FIG. 3). During this step, each network device involved in the localization process (locator device) is responsible for estimating a line of sight angle with the incoming device (according to the principle described above in relation to Figure 3). The position of the device entering the network is then determined by selection and cross-checking of the lines of sight (according to the principle described above in relation to FIG. 4) and the coordinates of this position are then transmitted to the incoming device. During the step 1005, the incoming device determines the state of the area in which it is located, by matching the position coordinates with a map of the geographical areas of the network in which the coordinates of geographical areas are defined. of the network (according to the half-right method, the principle described above in relation to FIG. 8), each zone being associated with positioning quality information. It is recalled that this positioning quality information has either the favorable state, the unfavorable state or the neutral state (according to the principle described above in relation with FIG. 8). An exemplary map of geographical areas is illustrated in FIG. 6. In another embodiment, as described in alternative with reference to FIG. 8, the positioning quality information is defined with respect to a distance between the device incoming and one or more lines of sight between network equipment, and / or with respect to a distance between the incoming device and one or more disturbing obstacles.

In a first embodiment (illustrated in FIG. 10), it is considered that, if the positioning quality information has the unfavorable or neutral state, the positioning assistance method must be stopped. It is considered that it is a bad positioning.

In a second embodiment (not shown), it is considered that, if the positioning quality information has neither the favorable state nor the neutral state, the positioning assistance method must be stopped. It is considered that it is a bad positioning only for adverse states. If the positioning quality information has the unfavorable or neutral state, the user is informed, in step 1012, that the device (via the user interface 207) is incorrectly positioned by means of a first indicator, to induce him to move the incoming device. This indicator can take the form for example of a red light emitting diode or a digital frame displaying information relating to a degraded level of communication quality. In this case, the advanced communication functions are not implemented. The user can then restart the procedure from step 1002 after moving the device entering the network (it is necessary to again determine antenna orientation angles).

If the positioning quality information has the favorable status, the user is informed, at step 1006, of correct positioning (via the user interface 207) by means of a second indicator. This indicator can take the form for example of a green light emitting diode. In this case, a second phase is started in which an indication reflecting the actual level of communications quality in the position occupied by the incoming device is also provided to the user. This second indication may, for example, be related to a measurement of BER (or power) of communications between the incoming device and a device of the preferred network or to an average of BER (or power) measurements of communications between the device. incoming and a set of network devices with which it can communicate online in direct view.

Step 1007 consists in selecting one or more reference devices (among those which could obtain a line-of-sight angle with the device entering during the locating phase performed in step 1004) that can serve as a basis for bringing the incoming device to improve the quality of its radio communications with this or these reference devices. This selection is based on a particular criterion according to which no unfavorable zone must be situated between the incoming device and a reference device. It is considered indeed that it is harmful in terms of communication quality to bring an incoming device closer to a network device if an unfavorable geographical area is present between these two devices (according to the principle described in relation with FIG. 9). In another embodiment, as described in alternative in relation with FIG. 9, this selection is based on a criterion according to which there is no line of sight between network equipment between this network device considered and the incoming device and or the distance between an obstacle and the segment representing the line of sight between this network device and the incoming device is greater than a predetermined threshold value. The incoming device determines the level of communication quality that it has with the reference device (s), for example using the BER or reception power measurements previously obtained by these same devices during the localization phase. the incoming device (step 1004 and step 910 of Figure 9).

In a particular embodiment where the incoming device is equipped with a programmable antenna, the determination of the communication quality level can also take into account the measurements made by the incoming device, during the step 1016 described above, these measurements. to provide a better guarantee of accuracy of communication quality measurements.

The communication quality level thus determined is then provided to the user during step 1008 by means of a series of light-emitting diodes, for example, situated at the level of the user interface 207. According to a particular embodiment , the indication of the level of communication quality provided to the user is explicit information of the measured power level.

Thus, in view of the level of communication quality indicated for this position, the user may be encouraged to move the incoming device to adjust the position of the latter, if this level of quality is insufficient. A new measurement of the communication quality level is therefore implemented in step 1009 after a certain delay (of the order of 10 ms for example) in order to update the level of communication quality indicated to the user. (the algorithm returns to step 1008). In parallel with this step, at regular intervals, an update of the position information of the incoming device (coordinates of the device entering the orthonormal frame considered) is performed at step 1011. It consists more particularly in the transmission of a radio location frame during the transmission time slot allocated to the incoming device during multiple superframe cycles. Its main role being to launch a location phase, the location radio frame therefore causes a new position measurement of the device entering the other devices of the network (according to the same principle as step 2004). Upon receipt of updated position information, the incoming device checks whether it is still in a favorable geographical area of the network. If this is the case, the communication quality level is again determined with the information from this new location phase as described above and is then indicated to the user during step 1008 by means of a series of light emitting diodes located at the user interface 207. If this is not the case, the incoming device informs the user of its position in an unfavorable geographical area of the network, then disconnects from the network (back to the steps 1012 and 1013).

Thus, it is possible for the user to refine the positioning of the incoming device using communication quality level measurements, while ensuring that it does not fit into an unfavorable geographical area of the network. . It should be noted that when the incoming device is positioned satisfactorily in the network, that is to say it is positioned in a favorable area, the advanced communication functions can be implemented.

FIG. 11a illustrates an exemplary structure of an insertion request, such a request comprising the following fields: a UniqueNode field ID 1100, providing information on the unique identifier assigned by the manufacturer of the communication device issuing the request; insertion ; an antenna type field 1101, providing information on the type of antenna (simple antenna or programmable antenna) which is provided with the communication device transmitting the insertion request; an Info_angles_field 1103, comprising the line of sight angle values, as well as the reception power level associated with each angle (according to the principle described above in relation to FIG. 5) by the communication device transmitting the insertion request in the case where the latter has a programmable antenna; a miscellaneous field 1104, giving information on various information relating to the nature of the communication device transmitting the insertion request message for example (antenna parameters such as the transmission mode (transmission or reception), etc.), or the nature of the data that it can send or receive (audio data, video, ...), etc. In particular, the insertion request is transmitted by the incoming device and must be received by at least one of the devices of the network. FIG. 11b illustrates an exemplary structure of an acknowledgment message of an insertion request, such a message comprising the following fields: a UniqueNode field ID 1107, giving information on the unique identifier assigned by the manufacturer of the device communication that issued the insertion request; an ACK Status field 1106, providing information on the acknowledgment status (that is to say, positive or negative acknowledgment) associated with the insertion request; - A PHY field ID 1105, providing information on the unique identifier within the network allocated by the central device to the device that issued the insertion request. In particular, the acknowledgment message is transmitted by several devices of the network to ensure, at least once, its reception by the incoming device. FIG. 11c illustrates an exemplary structure of a location radio frame, such a message comprising the following fields: a PHY field ID 1108, giving information on the network identifier of the equipment for which the message is intended. In the case of the radio location frame, this field takes a particular value called "all recipient" (or broadcast in English) which means that the message must be interpreted by all network equipment. a field radio_de_location 1109, including information to trigger the localization phase of the incoming device (according to the principle described above in relation to Figure 3). This information must be known to other devices in the network. In particular, the location radio frame is transmitted by the incoming device to allow certain network devices to evaluate the line of sight angles with respect to the incoming device.

Referring now to FIG. 12, a schematic example of a coverage intersection zone 1205 for a pair of transmitter / receiver devices 630, 640 communicating in a communication network according to a particular embodiment of FIG. invention. More particularly, the communication network is a home cinema type wireless communication network such as that described in FIG. 6, comprising source devices 610 and 611, as well as a plurality of destination devices 620, 630, 640. , 650, 660. Each device in the network operates as a transmitter / receiver. The network device 630 is now considered as a transmitting device transmitting with a transmission angle of 180 ° to cover the entire network and the device 640 as an associated receiver device. Transmitting device 630 has a quasi-omnidirectional antenna (relative to the extent of the communication network), whose associated coverage area (not shown in the figure) is estimated to be that produced by an angle of 180 ° between axes. (x'o 1200, xi 1202) and (x'o 1200, x2 1203). The receiving device 640 has a directional antenna whose main selectivity lobe is represented by the coverage area 1205 of its receiving antenna, corresponding to the space between the axes (xo 1201, xi 1202) and (xo 1201, x2). 1203). The coordinates of the vertices xo 1201, xi 1202 and x2 1203 are defined in a predefined mark 1270, depending on the configuration of the communication network.

Thus, the receiving device 640 is responsive to any power loss of the signal transmitted by the transmitting device 630, detected in the receiving coverage area 1205. In sum, by detecting a power loss of the signal received from a transmitter device of the network, the power of the signal being measured and compared with a theoretical power "unladen", that is to say in ideal conditions of transmission (without obstacle or disturbance), a receiving device of the network is therefore able to detect the presence of an obstacle, or a disturbing object, in the intersection area of covers 1205 relative to the transmitting device. For the sake of clarity in the remainder of the description, a reception coverage area will be assimilated to an intersection area of covers for a pair of transmitter / receiver devices. In reality, an intersection zone is an intersection between a transmission coverage area and a reception coverage area. In the following, a coverage intersection area at which a power loss is detected will be designated as a disturbed area.

FIG. 13a illustrates an example of an overlap zone in a wireless communication network according to one particular embodiment of the invention. In a similar manner to FIGS. 6 and 12, it is considered that the communication system of FIG. 13a is a home-cinema wireless communication network comprising audio and / or video content source devices 610 and 611, as well as a plurality of recipient devices 620, 630, 440, 650, 660. Each network device operates as a transmitter / receiver. In this case, we also consider two intersection zones of covers 1341 and 1361 relating to the two pairs of transmitter / receiver devices respectively 630/640 and 620/660.

The central device of the network determines the coordinates of the vertices xi 1371, x2 1372, x3 1373 and x4 1374 of the overlap area 1375 (also hereinafter referred to as "lap polygon") of the intersection areas of covers 1341 and 1361. If the intersection areas of covers 1341 and 1361 each have a high level of disturbance, the cover polygon 1375 may then correspond to an area in which there is an object (or obstacle), the latter being disturbing for the communications of the two intersection areas of covers 1341 and 1361. It is therefore possible to refine the determination of the size of the covering polygon 1375 by considering the intersection of the cover polygon 1375 with at least one other disturbed area of the network, if such is the case. Such a method of determining overlap area 1375 can be based, for example, on Weiler-Atherton's polygon clipping algorithm, as illustrated hereinafter in connection with with Figure 13b. FIG. 13b schematically illustrates a method for determining an overlap zone 488, based on a Weiler-Atherton polygon intersection algorithm (also called "polygon clipping"). Two intersection areas of covers 1390 and 1391 relating to two pairs of transmitter / receiver devices, respectively 1382/1380 and 1383/1381, are considered, the intersection zones of covers 1390 and 1391 having a strong perturbation. The steps of the algorithm, performed at a central device 1392 of the network, are as follows: - choice of one of the two disturbed polygons 1390 and 1391 as a windowing polygon. In this example, the polygon 1390 is chosen as a window polygon; calculating the points of intersection 1384, 1385, 1386 and 1387 of the polygons 1390 and 1391, knowing the equations of the segments of each of the sides of the polygons 1390 and 1391 in a common coordinate system 1270; determining the entry and exit points of the polygon 1391 in the windowing polygon 1390. Since the polygon 1391 is convex, it should be noted that the entry points coincide with the intersection points 1384, 1385, 1386 and 1387 of the 1390 and 1391 polygons. It is important to note that by traversing the windowing polygon 1390 in a counterclockwise direction, a point of intersection is said to be input if the polygon 1391 enters the polygon 1390, a point of intersection being said of exit if the polygon 1391 leaves the polygon 1390; choice of an initialization point for the contour of the polygon of intersection of the polygons 1390 and 1391. The selected point here is the point of intersection of the polygons 1390 and 1391 having the smallest abscissa value in the reference 1270, point 1384; - traversing the edges of the intersection polygon by applying the following rules: o choose the starting point 1384 as the initial starting point; o traverse the windowing polygon 1390 counterclockwise to the following point of entry or exit: • if the starting point was an entry point and the arrival point as a point of entry. output, the two points are stored as vertices of the intersection polygon 1388 of the polygons 1390 and 1391. The border of the intersection polygon 1388 is then the border of the polygon 1391 joining the entry and exit points; • If the starting point was an exit point and the arrival point an entry point, the two points are memorized as vertices of the intersection polygon 1388 of the 1390 and 1391 polygons. The polygon border intersection 1388 is then the border of the windowing polygon 1390 joining the entry and exit points; • initialize the starting point as being the previously considered end point; • Repeat the previous steps until the end point is confused with the initial starting point 1384. At the end of this path of borders, we finally obtain the intersection polygon 1388 having at its vertices the points 1384 , 1385, 1386 and 1387 and for sides the segments [1384; 1385], [1385; 1386], [1386; 1387] and [1387; 1384]. Referring now to FIG. 14, the structure of a notification message of the covert intersection zone disturbance state is presented. Once a receiver device 640 has measured, for a transmitting device 630 of the communication network, the disturbance state (ie the abnormal loss of power of the transmission signal) relative to the zone d associated intersection of covers, the receiving device 640 transmits information relating to the state of disturbance of the intersection area of covers 1205, in the form of a notification message, on the communication network. More precisely, the notification message of the disturbance state comprises: a network device identifier field 1400 carrying information relating to the unique identifier of a device of the network; a disturbance status field 1401 providing information on the state of disturbance of a zone of intersection of covers, for a given couple of transmitter / receiver devices, the field 1401 itself comprising: a subfield 1402 of transmitter device identifier, providing information on the unique identifier of the network transmitter device relating to the coverage intersection zone considered for the field 1401; a sub-field 1403 of receiver device identifier, providing information on the unique identifier of the network receiver device relating to the coverage intersection zone considered for the field 1401. It could be the identifier of the device local (that is to say, information identical to that contained in the field 1400), or the identifier of a receiving device remote network (the field 1401 is then a field transmitted by a remote receiver device, relayed by the receiver device then acting as a relay device); a subfield 1404 perturbation status information on the state of disturbance of the intersection area covers, for the couple of transmitter / receiver devices identified by the subfields 1402 and 1403. In a particular embodiment , it may be a binary information that can take, for example, the value 0 when the intersection area of covers is considered disturbed and the value 1 when it is considered undisturbed. FIG. 15 presents a flowchart of an algorithm for locating zones of presence of disturbing objects (zones of disturbances) according to a particular embodiment of the invention. Once the information pertaining to the state of disturbance of the intersection zones of network covers collected, as transmitted on the network by the receiving devices, the central device can then determine the zones of presence of at least one obstacle of the network. network causing disturbances within the network. In such a case, the algorithm makes it possible to define the position, relative to the devices of the network, of a polygonal zone within which the disturbing obstacle is located. In a first step 1500, the central device of the network sorts all the intersection areas of coverage of the network according to their respective state of disturbance, as received from the network remote devices.

The central device then establishes, in a step 1501, a list comprising all the identified disturbed zones (called "disturbance list"), then a list comprising all the undisturbed zones identified (called "non-disturbance list"). In a step 1502 in a step 1503 of the algorithm, the central device of the network then performs, for each intersection area of covers present in the perturbation list, a polygonal intersection correlation with the set of other intersection area covers present in the disturbance list, according to mechanisms previously mentioned in relation to Figures 13a and 13b. The set of polygonal intersection overlap zones thus obtained is then stored in a list of overlapping zones, during a step 1504. The set of polygonal subtraction overlap zones thus obtained, corresponding to the zones of presence of disturbing objects, is then stored in a list of masking zones, in step 1505 of the present algorithm.

Each zone of presence of disturbing objects of the masking list thus updated corresponds to the relative positioning of disturbing objects of the network with respect to the transmitter and receiver devices of the network.

Claims (16)

REVENDICATIONS1. A method of assisting the positioning of a given device in a wireless communication network comprising a plurality of communication devices, characterized in that it comprises the steps of: - obtaining (1004) the position of the given device; associating the position obtained of the given device with a positioning state, favorable or unfavorable, according to a first predetermined rule; if the state associated with the position obtained from the given device is favorable: obtain (1007) information relating to a level of quality of communication between the given device and at least one reference device, each reference device being determined according to a second predetermined rule; * providing (1008) said information relating to a communication quality level; - If the state associated with the obtained position of the given device is unfavorable: * provide (1012) predefined information relating to a first level of communication quality. 2. Method according to claim 1, characterized in that the step of associating the obtained position of the given device with a positioning state comprises the step of: determining a geographical area in which the position obtained from the device is located given, and in that the associated positioning state corresponds to a positioning quality information associated with said geographical area. 25 3. Method according to claim 2, characterized in that it comprises in advance a step of: - obtaining a representation of a plurality of geographical areas each associated with said positioning quality information. 4. Method according to any one of claims 1 to 3, characterized in that, according to said second predetermined rule, each reference device is a communication device such as no geographical area, associated with a quality information of positioning corresponding to the unfavorable state, is located between the reference device and the given device. 5. Method according to any one of claims 1 to 4, characterized in that, if the state associated with the obtained position of the given device is favorable, it comprises a step of: - providing (1006) predefined relative information at a second level of communication quality. 6. Method according to claim 5, characterized in that the second level of communication quality is strictly higher than the first level of communication quality. 7. Method according to any one of claims 1 to 6, characterized in that the first default communication quality level is representative of a state where no communication is possible between the given device and the plurality of devices. network communication. 8. Method according to any one of claims 1 to 7, characterized in that, according to said first predetermined rule, the positioning state is favorable if, assuming that a communication device is placed in a geographical area in which the position of the given device would be obtained, the following two favorable criteria are met: a communication quality level, between the device placed in said zone and at least one other of said communication devices, is greater than a communication quality threshold. predetermined; and a level of disturbance of said network by said device placed in said zone is less than a predetermined disturbance threshold; in that, according to said first predetermined rule, the positioning state is unfavorable if, assuming that a communication device is placed in said zone, at least one of the two favorable criteria is not respected. 9. Method according to any one of claims 1 to 8, characterized in that it comprises a step of associating the obtained position of the given device to a neutral position state if said obtained position of the given device has been associated in the state of favorable positioning or in the unfavorable state, and in that the method comprises the same steps if the state associated with the position obtained from the given device is the favorable state or the neutral state. 10. Method according to any one of claims 1 to 8, characterized in that it comprises a step of associating the obtained position of the given device to a neutral position state if said obtained position of the given device has been associated in the state of favorable positioning or in the unfavorable state, and in that the method comprises the same steps if the state associated with the position obtained from the given device is the unfavorable state or the neutral state. The method of any one of claims 1 to 10, characterized in that said information relating to a communication quality level is explicit information corresponding to a signal power level received during said communication. The method according to any one of claims 1 to 11, characterized in that said step of obtaining (1004) the position of the given device comprises steps of: - for at least two communication devices, determining an angle of line of sight with respect to the given device, comprised between a predetermined reference axis and an estimated line of sight axis between the communication device and the given device; determining the position of the given device according to said determined line of sight angles. 13. Method according to any one of claims 8 to 12, characterized in that the communication network comprises a set of couples consisting of a transmitting device and a receiving device, each of the devices having a communication coverage area (1361, 1341) determined, the coverage areas of each pair having a zone of mutual intersection (1375), and in that at least one of said favorable criteria is related to a given number of intersection zone (s). disturbed mutual system (s) for a considered geographical area, a disturbed mutual intersection zone having a given perturbation state according to a determined criterion of communication quality between the devices of the pairs corresponding to said disturbed mutual intersection zone. 14. Computer program product, characterized in that it comprises program code instructions for the implementation of the method according to at least one of claims 1 to 13, when said program is executed on a computer. A computer readable storage medium storing a computer program comprising a set of computer executable instructions for carrying out the method according to at least one of claims 1 to 13. 16. Device for assisting the positioning of a given device in a wireless communication network comprising a plurality of communication devices, characterized in that it comprises: means for obtaining the position of the given device; means for associating the position obtained of the given device with a positioning state, favorable or unfavorable, according to a first predetermined rule; means, activated if the state associated with the position obtained from the given device is favorable: to obtain information relating to a level of quality of communication between the given device and at least one reference device, each reference device being determined according to a second predetermined rule; * to provide said information relating to a level of communication quality; - Means, activated if the state associated with the obtained position of the given device is unfavorable, to provide a predefined information relating to a first level of communication quality. 20