FR2863133A1 - Dual mode mobile telephone system uses selected technology according to user preference and signal availability in current mobile location - Google Patents

Abstract

The mobile telephone (10) may be connected to a network via one of two technology systems (T1,T2). This is dependent on preferences held in memory, and the coverage zone of the respective systems. This provides access the network by the best technology available at a particular time. The mobile telephone (10) may be connected to a first technology system (T1) if the mobile is located within the coverage zone (B1, 20) for this technology. This provides connection to the network (40). If the mobile moves, it may leave this coverage zone, but enter another coverage zone (B2, 30) corresponding to a second technology system (T2). This also provides access to the same network (40), albeit by a different route. The phone uses one or the other technology, but must not use both at once. The user may classify these technologies in order of decreasing preference within a memory, enabling a program to access the network by the best technology available at a particular time according to the criteria provided by the user.

Description

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  The invention generally relates to the field of communication systems, and relates more particularly to a method, a device and a program for performing a permutation between several heterogeneous wireless technologies.

  STATE OF THE PRIOR ART The introduction of mobility in networks has necessitated the definition of new rules in relation to conventional fixed networks. The principles of localization update and handover have thus appeared with cellular networks.

  In these systems, the same network is divided into zones. The system must know at any time the position of a given mobile to be able to reach it. This is made possible by the location update: the address of the area where the subscriber is located is called the location pointer and is updated by combining a periodic refresh and a refresh on a zone change.

  Each base station periodically broadcasts on a beacon channel the number of the location area to which it belongs. For its part, the mobile periodically listens to the beacon channel and stores the number of the location area in which it is located. If the mobile realizes that the number received is different from the one previously stored, it indicates its new position to the network. There is also a periodic location update where the terminal transmits messages at regular intervals to the network to indicate its current position.

  In these systems, the purpose of the location update is to manage roaming, allowing to know the position of a given mobile in a large network. It is therefore the update of the location of a mobile when moving within the same network.

  On the other hand, if the mobile passes from the coverage area of a first wireless network to the coverage area of a second wireless network of a different nature from the first, there is currently no possibility of guaranteeing a certain continuity of service, if not by deploying costly physical infrastructure.

  There are several categories of wireless networks: WPANs, which, in return for a limited coverage area, offer good speeds and an optimal level of security; WLANs, for which the coverage area is wider. The speeds offered by WLAN technologies are higher than what is conventionally available in other wireless technologies, and their cost of use is lower than that of these other technologies. However, the security level of WLAN networks is not optimal. There are also mobile networks (2G, 2.5G, 3G and 4G) that offer much larger coverage areas than WPANs or WLANs, with a good level of security in transfers, but for which data rates are more or less low and above all the costs of use are high. Satellite networks are another type of wireless network, whose range is very large, but their bit rates are relatively low (compared for example with those obtained in WLAN), and the costs of using these networks are relatively high.

  There is also a whole range of equipment that can access a given network (Internet, Intranet ...) by using several of these wireless technologies. If the user is in an area that is not covered by any of the above technologies, they will not be able to access the desired network.

  If only one of the technologies makes it possible to have access to this same network, the user will have to use this technology. On the other hand, when the equipment is in an area covered by several network access technologies, the user can use any of these technologies to access the network. Most often, the user has a preferred technology (for questions of cost, level of security, flow ...). He will therefore choose to use, wherever possible, this preferred technology. But if it leaves the coverage area of this technology, it is disconnected from its network and must reconnect using one of the other technologies that allow coverage to the network.

  Throughout its journey, the user must constantly monitor the levels of signals received for each technology so as to predict when he will be disconnected from the network because he leaves the coverage area of his favorite technology, and he will have to choose one of the other available technologies which allow him to have access to the network.

  There is therefore a need to create a handover protocol between two wireless technologies that will allow a user who travels in a non-uniformly covered area by each of these technologies to use a preferred technology to access the network each time. that it is possible, then a second favorite technology when the first technology is not enough ...

  The user will thus specify a ranking of available access technologies in order of preference according to several criteria that he can determine.

  Disclosure of the Invention The present invention relates to a method, a device and a program for performing a switch between several heterogeneous wireless technologies (i.e. different technologies).

  We have a mobile equipment (for example a PDA, a mobile phone, a laptop ...) which integrates n distinct wireless technologies, n being an integer greater than or equal to 2. All these technologies allow the mobile equipment to have access to the same network. This mobile equipment is the device that makes it possible to implement the method.

  The method will be implemented by means of a program installed in memory of the device. The program makes it possible to carry out the events described in FIGS. 2 and 3.

  In this document, we refer to wireless technology as any technology that provides access to a network, equipment, and / or system through the transfer of data by air, that is, without a wired connection between the mobile equipment and the network, equipment or system concerned. These technologies can for example be: Bluetooth (VI or V2), 802.11a, 802.11b, 802.11g, Hiperlan 1, Hiperlan 2, HomeRF, UWB, GSM, GPRS, UMTS, BLR, LMDA, TETRA, satellite, ... but also all wireless technologies that will appear in future years.

  The technologies are ranked in order of decreasing preference: we will call the preferred technology in the rest of this document (this may be the technology offering the best quality of service, the best bit rate, or a lower connection cost). T2 technology is the second preferred technology, T3 technology is the third preferred technology, and so on for all technologies.

  The ranking is defined by the user according to criteria that he considers more or less important. The user may want to use a so-called reliable technology and offering a bit rate of at least 1 month, it may for example choose between Bluetooth V2 or satellite, rather than 802.1 lb (deemed unsecure) or GPRS (2863133 4 insufficient flow) ). The ranking of the user according to these criteria will then be, for the four previously mentioned technologies: T1: Bluetooth V2, T2: satellite, T3: GPRS and T4: 802.11b. This user will use Bluetooth whenever possible, then the satellite, then the GPRS then as a last resort WiFi. Another user, who will not have the same criteria (cost criteria, range ...), will obtain a different ranking for the four technologies given as examples.

  T1 technology covers a BI area. When the mobile equipment is in the BI zone, it will have access to the network using T1 technology. If the mobile equipment moves, it can move out of T1's coverage area. It will then have to use T2 technology to continue to have access to the same network, provided that it is in the coverage area of T2 technology, which we will call B2. If the mobile device can not access the network using T2 technology, it tries to access it with T3 technology, and cyclically tests the received signal level for each technology until one of the technologies agrees. If the mobile device returns to the BI zone, it will use T1 technology again to gain access to the network.

  If, possibly, the mobile equipment is not in BI, B2, or any other coverage area of other technologies, then it can no longer access the network.

  The invention describes a method for allowing the passage of one technology to another without the intervention of the user of the mobile equipment. The method can also be used with user intervention.

  The method is based on a program making measurements of the received signal level of the different technologies present: regularly (at a frequency determined by the PM timer), the mobile equipment makes measurements of the signal levels received from the different technologies and compares them at threshold values. These measures will allow mobile equipment to identify and use the highest-ranked accessible technology at the time of measurement to access the network.

  The procedure of switching from one technology to another is therefore done on the initiative of the mobile equipment (device on which the program is installed), which will decide when to use one technology rather than another to have access to the network.

  Presentation of the Different Figures Figure 1 shows a case of use of the invention with only two technologies Ti and T2, which respectively generate a coverage area BI and B2.

  Figure 2 illustrates the transition from one technology to another depending on the measurement of the level received from the T1 technology, again in the case where there are only 2 technologies.

  Figure 3 is a block diagram showing the various steps corresponding to the invention that are performed by the mobile equipment of Figure 1.

  Detailed presentation of an embodiment of the invention In the presentation, we will take the case (illustrated by Figures 1, 2 and 3) where there are only 2 technologies (T1 and T2, T1 being the technology preferred).

  Figure 1 explains the principle of the invention. Mobile equipment 10 is connected to a network 40 by means of T1 technology. In Figure 1, the mobile equipment 10 is in the BI coverage area 20 of T1 technology. By moving, the mobile equipment 10 can leave the BI coverage area 20 of T1 technology. He can then enter the coverage area B2 of T2 technology. When the mobile equipment 10 is in the coverage area B2 30, it still has access to the network 40. If the mobile equipment 10 is in both the coverage zone BI 20 of the technology T1 and in the zone B2 30 coverage of T2 technology, it will use T1 technology (which is the preferred technology) to access the network. It may also happen that the mobile equipment 10 is not in the coverage area BI 20 nor in the coverage area B2 30, it can not then have access to the network 40. The mobile equipment 10 will use either the technology T1, T2 technology to access the network 40, but must not use the two technologies jointly to access the network 40.

  Figure 2 describes how mobile equipment 10 decides to move from one coverage area to another (from coverage area BI 20 to coverage area B2 in Figure 1, or vice versa). . All measurements and actions are performed by the program installed in memory of the device.

  The axis 200 represents the signal level received from the T1 technology by the mobile equipment 10. Suppose that at a given moment the mobile equipment 10 is in the coverage area BI 20 of the T1 technology. It performs regular measurements of the received signal level. If this received signal level drops below the threshold 1 210, the mobile device abandons the T1 technology in favor of the T2 technology to access the network 40. The mobile equipment 10 continues to perform regular measurements to determine the signal level received from T1 technology. These measurements are made at a periodicity defined by a timer called PM timer (for PerMutation). When, after a measurement of the signal level received from the T1 technology, the mobile equipment 10 detects that the signal level is greater than or equal to the threshold 2220, it switches back under T1 technology to access the network 40. The use of the two thresholds 210 and 220 makes it possible to prevent the mobile equipment 10 from switching too often between the two technologies Ti and T2.

  Thresholds 210 and 220 will depend on T1 technology but also on the sensitivity of the mobile equipment antenna 10.

  Figure 3 explains the sequence of tasks performed by the mobile equipment 10. All measurements and actions are performed by the program installed in memory of the device. Step 300 corresponds to the powering up of the mobile equipment 10. Once powered up, the mobile equipment 10 performs a measurement of the signal level received in the Ti technology (step 302). In step 304, the mobile equipment 10 makes a decision: it compares the signal level it has measured with the value of the threshold 210 of FIG. 2. If the measured signal level is greater than this threshold value , the task then performed by the mobile equipment 10 is the task 306: it uses the T1 technology, then in the step 308, it accesses the network 40 using the Ti technology. Frequently, according to the frequency defined by the PM timer, the mobile equipment 10 remeasures the received signal level of the T1 technology. If, during one of these measurements, the level obtained is less than or equal to the threshold 1 210, then step 304 of FIG. 3 continues with step 310: the mobile equipment 10 this time carries out a measurement of signal level received from T2 technology. In step 312, the mobile equipment 10 estimates whether this level is sufficient. If so, it uses the T2 technology (step 314) to connect to the network (step 316), and continues to measure the received signal level of the T1 technology (step 318), again according to the frequency defined by the timer PM. He then compares this new value with the value of the threshold 2 220 (step 320). As long as the received signal level of the Ti technology is less than or equal to the threshold 230 (No output of step 320), the mobile equipment 10 continues to use the T2 technology to access the network 40. a measurement, the mobile equipment 10 detects that the received signal level of the technology 2863133 7 Ti becomes greater than or equal to the threshold 2 230 of Figure 2, so it no longer uses the T2 technology, but again the T1 technology to access the network 40 (Yes output of step 320).

  Finally, if after following the No output in step 304, the mobile equipment 10 detects that the received signal level of the T2 technology is insufficient (output No of step 312), it will consider that it is not in the BI coverage area 20 of the T1 technology, nor in the B2 coverage area T2 of the T2 technology of Figure 1, and therefore it can not access the network 40. The mobile equipment 10 then performs after a period defined by the timer PM, a new measurement of the received level of the Ti technology (No output of step 312) and is found in step 302.

  An output Yes after step 304 or step 320 indicates that the mobile equipment 10 is in the coverage area B1 of the T1 technology; likewise, a Yes output after step 312 indicates that the mobile equipment 10 is within the B2 coverage area of the T2 technology (see Figure 1).

  The method described in the block diagram of FIG. 3 thus allows the mobile equipment 10 of FIG. 1 to determine, by means of the program stored in the device, whether it is in a coverage area that allows it to access to the network 40, and in this case, to be able to choose the preferred technology to access this network.

  Industrial Applications of the Invention The industrial applications of the invention are very numerous.

  The invention allows the automatic selection of a preferred wireless technology to access a given network, without user intervention.

  For example, take the case of a user who has a computer with access to GPRS technology and 802.11b technology. At home, the user has access to the Internet through 802.11b technology. He may also gain access to the Internet using GPRS, but prefers to use 802.11b because it is less expensive to use. When he leaves home with his laptop, this user moves away from his 802.11b access point, and at a certain point, the received signal level becomes insufficient. The method will allow the computer to automatically switch to GPRS technology so that the user can continue to have access to the internet. During its journey, the user 2863133 8 can go on the Internet via GPRS. Upon arriving at the user's workplace, the laptop detects the presence of 802.11b technology at a sufficient level. It will therefore relocate under this technology, less expensive than GPRS, so that the user can continue to have access to the Internet.

  We will present a second application of the invention in a second example. Take the case of a company that uses 802.11b technology to connect its computers to the corporate network. This company then decides to use a more efficient technology (for example 802.11 g). Computers connect to the corporate network using this new technology. In the event of a problem, technical or otherwise, the process can be used to instantly roll back all of the company's IT fleet under 802.11b technology, which becomes a support technology until the problem is solved. At this point, the computer park will rebasculate again under the preferred technology (802.11g).

  We can still imagine many other examples of industrial applications of the invention: the method, the device and the program described in this document can indeed be applied to many cases. 25

Claims (7)

claims   A method for performing a switchover between two heterogeneous wireless technologies, characterized in that it performs measurements of the received signal level for each of the technologies concerned at a frequency defined by a PM timer and compares the received signal level. with the two predefined threshold values, specific to each technology and determined by the sensitivity in own reception of the mobile equipment.   2. A method for performing a switch between two heterogeneous wireless technologies as claimed in 1, characterized in that it identifies the highest ranked accessible technology at the time of measurement to access the network when the device is put energized and in that it performs, at its initiative, the automatic switching device for this technology.   3. A method for performing a permutation between two heterogeneous wireless technologies according to any one of claims 1 or 2, characterized by its automatic triggering, without human intervention; its manual trigger or the choice it allows between these two types of triggers.   4. A method for performing a permutation between two heterogeneous wireless technologies according to any one of claims 1, 2 or 3, characterized in that one of the two thresholds specific to each present technology corresponds to the perception of the zone. cover in which it is located by the mobile equipment.   5. A method for performing a permutation between two heterogeneous wireless technologies according to any one of claims 1, 2, 3 or 4, characterized in that one of the two thresholds specific to each present technology corresponds to the perception the coverage area by the mobile equipment while it is outside this area and uses other technologies to access the network.   6. A method for performing a permutation between two heterogeneous wireless technologies according to any one of claims 1, 2, 3, 4 or 5, characterized in that one of the two thresholds specific to each present technology corresponds to the perception of the coverage area by the mobile equipment while it is outside this area and does not have access to the network.   7. A device for carrying out the method according to any one of claims 1, 2, 3, 4, 5 or 6, characterized by the presence of a mobile equipment incorporating at least two different wireless technologies, classified according to a sequence preferably decreasing, each generating a coverage area and giving access to the same network, ie access to a server, a computer or any other equipment that can make accessible data available to mobile equipment in read, write, execute, download or to which the mobile equipment can send data by download. 30 35