Abstract:
The invention relates to a method for establishing an at least partially wireless data transfer connection between a remote application and a controlling application. The wireless connection is implemented by a wireless terminal connected to the remote application. The wireless terminal can select from a group of allowable connection parameter settings a usable connection parameter setting for the wireless link, if a default connection parameter setting for the wireless link is not usable. The invention relates also to a wireless terminal using the method and a computer program implementing the method in the wireless terminal.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates to a method for using a backup in a telecommunication connection where a wireless data transfer connection between a remote application and a controlling application should be established, and where the wireless link from the remote application is implemented by a wireless terminal connected to the remote application.  
       BACKGROUND OF THE INVENTION  
       [0002]     Series of fundamental changes have happened in communication culture and technologies. Some twenty years ago mobile devises were introduced to customers for voice communication. Subsequently customers learned also to satisfy their other communication needs using data services on their mobile devices. Also a possibility to use the Internet by mobile devices was introduced.  
         [0003]     The next quite obvious step was to extend mobile connectivity beyond human beings. So individuals can nowadays communicate with wireless devices with other individuals, devices or systems. The next step forward was a solution where two or more machines or applications connected thereto are communicating with each other without a human touch by at least partly wireless methods. Those solutions are often called machine-to-machine solutions or shortly by an abbreviation M2M.  
         [0004]     Machine-to-machine applications combine features of both the information and telecommunication technology. Some examples of possible applications are: Telemetry: utility meter reading, parking meters; Public traffic services: traffic information, electronic tolling; Sales &amp; payment: vending machines, photocopiers; Service &amp; maintenance: elevators, industrial machines; and solutions in areas of: telematics in vehicles, security and surveillance, telemedicine, fleet management and home applications.  
         [0005]     As mentioned above M2M systems can be quite complicated.  FIG. 1  illustrates an example of a system according to the prior art. There is a remote application  15  to or from which all communication must be done trough a wireless terminal  14 . In the example of  FIG. 1  the terminal  14  is a GSM terminal (Global System for Communications). The GSM terminal  14  resides in a cell which belongs to a GSM network  10 . The GSM network  10  is connected to some INTRANET  12 , which can be for example a corporate data network, through a gateway  11 . Gateway  11  can comprise also a Gateway Access Software. INTRANET  12  includes also a controlling application  13 , which is used as a control means for the remote application  15  i.e. the control application is a host to the remote application. This controlling application  13  includes also all connection parameter settings  131  (CPS  1 , CPS  2 , and CPS n), which the controlling application  13  can utilize in its communication. Which one of the two mentioned applications starts a communication connection depends on a particular situation.  
         [0006]     Also the GSM terminal  14  includes its own connection parameter settings  141  (CPS  1 , CPS  2  and CPS m). There can be some differences between the connection parameter settings in the GSM terminal  14  and the controlling application  13  located in INTRANET  12 .  
         [0007]     Next will be illustrated an example how this prior art system functions in an exemplary situation where the controlling application  13  retrieves information from the remote application  15  by exploitation of one of the possible connection parameter settings  131 . For sending a command to the remote application  13  the controlling application  13  establishes at first a data transfer connection  111  to the gateway  11 . From there the command is routed via a further data connection  101  to the GSM network  10 . The command is further routed by a service bearer on a radio channel  103  to the wireless GSM terminal  14 . If possible, a default service bearer defined in the CPS settings is used in the data transfer in the radio channel  103  between the core GSM network  10  and GSM terminal  14 . Some examples of the possible service bearers are: GPRS (General Packet Radio Service), EGPRS (Edge GPRS), HSCSD (High Speed Circuit Switched Data), CSD (Circuit Switched Data) and SMS (Short message Service).  
         [0008]     From the GSM terminal  14  the command is sent for example via a fixed connection  151  or via a proximity connection utilizing Bluetooth or other proximity network technology to the remote application  15 . The remote application  15  follows the command it has received. A result of the command can be that the remote application  15  sends some data back to the controlling application  13 . This is depicted by an arrow  152 . The route back to the controlling application  13  can be the route depicted above in a reversed order. The process ends when the controlling application  13  receives the data sent by the remote application  15 .  
         [0009]     It is also possible that the remote application  15  is an initiator in a connection setup attempt. In that case the connection setup will be made using a default bearer, which is defined to the remote application  15 .  
         [0010]     The default connection parameter setting, or in other words the default service bearer, which the GSM terminal  14  uses, can be defined by a command  153  given by the remote application  15  or controlling application  13 . In both cases the decision to be made must be done either in the controlling application  13  or remote application  15  but not in the wireless terminal  14 , which only follows those orders it has received. This kind of function is possible if in the design phase the application designer has also the capability to implement to the remote application special features, which are connected to the possible service bearers.  
         [0011]     So in the prior art the wireless GSM terminal  14  is not allowed to change the bearer service independently. A problem can arise when the default bearer service is not usable for some reason. In that situation the wireless GSM terminal  14  makes useless connection setup attempts which can all fail in the worst case. If the application designer has no taken this situation into account, the data transfer cannot succeed at all. Often the application designer is not capable or willing to design also the communication features needed and that is why the remote application  15  works perfectly only in limited environmental conditions.  
       SUMMARY OF THE INVENTION  
       [0012]     An object of the invention is to provide a new kind of wireless communication establishment procedure to a remote application where the remote application needs not to know which kind of a service bearer is to be used in the supporting wireless link.  
         [0013]     The objects of the invention are achieved by connection establishment method where the selection of an appropriate service bearer is done fully in a wireless terminal connected to the remote application. The terminal has a list of preferred service bearers and it makes the decision about which one of them is the most appropriate and also available. In this decision the terminal avails knowledge about data which the remote application wants to transmit, available service bearers and their expenses.  
         [0014]     An advantage of the invention is that the remote application can be designed simpler because there is no need to implement parts or software elements which are needed in data transfer in a supporting wireless link.  
         [0015]     Another advantage of the invention is that if changes to connection parameter settings are needed, these can be made directly to the terminal configuration either by controlling application or remote application.  
         [0016]     Another advantage of the invention is that the data transfer is more reliable than by using a system of prior art because the terminal can use anyone of the existing service bearers in the cellular network if needed.  
         [0017]     A further advantage of the invention is that it enables usage of several operators.  
         [0018]     A further advantage of the invention is that the order of the service bearers or the default service bearer can be changed according to terminal configuration which means that the remote or controlling application do not need to manage bearer selection.  
         [0019]     Yet another advantage of the invention is that the default service bearer will be resumed when conditions put by the user of the application are fulfilled.  
         [0020]     The idea of the invention is basically as follows: A wireless terminal, which is connected to a remote application, includes a list of service bearers in a preferred order. It comprises for example all usable service bearers and their connection parameter settings. That is why there is no need in the remote application, which is connected to the GSM terminal according to the invention, to be included connection parameter settings, which are needed if a service bearer used in the wireless link between the GSM terminal and core GSM network must be changed for one reason or another. The GSM terminal uses the connection parameter settings in the list in a defined order. If the first one in the list cannot be used, the GSM terminal moves to next one on its list. If the second one is not possible either, the GSM terminal moves to the next one in order and so on. This procedure recurs every time when there is a need to establish a data transmission connection from or to the remote application. If for some reason the default service bearer was not used in a data transmission, which already has been disconnected, a returning mechanism included in the invention changes back to the original service bearer. The wireless terminal according to the invention can also comprise a list of allowed service operators.  
         [0021]     Some preferred embodiments of the present invention are disclosed in the depended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The invention is described in detail below. Reference is made to the accompanying drawings in which  
         [0023]      FIG. 1  shows an example of a telecommunication network of a prior art,  
         [0024]      FIG. 2   a  shows an embodiment of a wireless terminal according to the invention,  
         [0025]      FIG. 2   b  shows a second embodiment of a wireless terminal according to the invention,  
         [0026]      FIG. 3  shows, as an example, a flow chart including main stages of the method according to the invention, and  
         [0027]      FIG. 4  shows, as an example, the main components of a wireless terminal where the method according to the invention is used. 
     
    
     DETAILED DESCRIPTION  
       [0028]      FIG. 1  was discussed in conjunction with the description of the prior art.  
         [0029]      FIG. 2   a  illustrates an example of the present invention. A remote application  15  is fixedly or proximity connected to a wireless terminal  24   a  according to a first embodiment of the invention. With an arrow  151  is depicted information or commands, which the wireless terminal  24   a  has received from a controlling application  13  located in some INTRANET (shown in  FIG. 1 ) and which will be inputted to the remote application  15 . With a second arrow  152  is depicted data that will be transmitted from the remote application  15  to the controlling application  13 . In this example data is transmitted via a wireless link  103  to a serving GSM network and from there to the INTRANET  12 .  
         [0030]     The remote application  15  has only those features which are necessary for its basic purpose or function. It is not needed to implement parts or functions, which are needed in data transmission in a serving telecommunication network. The serving network in the examples of  FIGS. 1, 2   a  and  2   b  is a TDMA-network (Time Division Multiple Access) for example a basic GSM network or a GSM network supporting also a GPRS service. However, the inventive idea can be implemented also in other cellular networks technologies.  
         [0031]     A wireless terminal  24   a  according to the first embodiment of the invention comprises control logic  242  and a functional block  241  for connection parameter settings: CPS  1 , CPS  2  and CPS m. Each one of the parameter settings corresponds to one given service bearer for example: GPRS, EGPRS, HSCSD, CSD and SMS. The preferred order of use of these connection parameter settings is predetermined. One of them is always a default connection parameter setting. The control logic  242  tries to use the default connection parameter setting when a new connection must be established. If this is not possible for some reason at all or if it does not succeed, the control logic  242  tries the next appropriate connection parameter setting. If also this second connection parameter setting is impossible to use, the control logic  242  chooses the third preferred connection parameter setting if there are more than two configured. This process can continue until the last possible connection parameter setting has been tried and it has also failed. If this unwanted circumstance has arisen, some alternative courses of action are depicted in connection of  FIG. 3 . The order in which the control logic  242  makes the establishment tryouts is advantageously defined during the application installation. However, according to the invention it is possible to change the originally defined order with an order given by the controlling application  13  located in the INTRANET  12 .  
         [0032]     The control logic  242  has a fixed connection  240  to the functional block  241 . Through this connection the control logic  242  can utilize the connection parameter settings and arrange and change the order of the available connection parameter settings. So if the controlling application  13  gives an order to the wireless terminal  24   a  to change the preferred order of the connection parameter settings  241 , the control logic  242  makes the ordered changes without any additional commands from the remote application  15 .  
         [0033]      FIG. 2   b  illustrates a second embodiment of the present invention. A wireless terminal  24   b  comprises control logic  242   a , first functional block  241   a  for connection parameter settings: CPS  1 , CPS  2 , CPS  3  and CPS m and second functional block  241   b  for operator selection: operator  1 , operator  2 , operator  3  and operator q. The control logic  242   a  has a fixed connection  240   a  to the first functional block  241   a . Through this connection the control logic  242   a  can utilize the connection parameter settings and arrange and change the order of the connection parameter settings in the first functional block  241   b . The control logic  242   a  has also a fixed connection  240   b  to the second functional block  241   b  where the preferred operator settings are. Through this connection  240   b  the control logic  242   a  can utilize the preferred operator settings and arrange and change the order of the preferred service operators.  
         [0034]     There are several possibilities how control logic  242   a  can function in the example of  FIG. 2   b . The first option is to choose first one of the service operators  241   b , which are also arranged into preferred order. The first one of them is set as default operator. If the default operator is not available, the control logic  242   a  selects an operator preferred next. When the service operator has been selected and there is need for communication, the control logic  242   a  subsequently selects the default connection parameter setting from connection parameter settings  241   a , i.e. a preferred service bearer. If it is not available, the next suitable connection parameter setting will be tried. If none of the possible connection parameter settings are available or cannot be used for some reason, the connection establishment is failed.  
         [0035]     A second possible option is that the connection parameter setting, i.e. the service bearer, is selected first. After that the control logic  242   a  combs the operator list  241   b . If the default operator can support the wanted service bearer, it will be used. However, if the default operator is incapable to offer wanted service bearer, the control logic  240   a  moves to the next preferred service operator. This process continues until a service operator, which can offer the wanted service, is found. If none of the possible service operators can support the asked service bearer, the connection establishment is failed.  
         [0036]     A third possible option is to use the connection parameter settings  241   a  and service operator list  241   b  in an arbitrary combination. In this option for example the default connection parameter setting, i.e. service bearer, can be selected first. After that the default operator is selected from the operator list. If it can support the selected service bearer, this operator will be the serving one. However, if the default operator cannot support the wanted service bearer, the next appropriate operator will be tried. This process continues until a service operator, which can offer the asked service, is found. If none of the possible service operators can support the asked service bearer, the control logic  242   b  returns to the connection parameter settings  241   b . It selects the next appropriate connection parameter setting and returns again to the service operator list  241   b . The order, in which the operator list is now used, can be the same as in the first pass of the operator list or the order can also be changed.  
         [0037]     In this third option either one of the possible selections can be done first: a selection from the connection parameter settings  241   a  or a selection from the operator list  241   b . It is also possible that the order of the items in either one of the lists can depend on the preceding selection of the other list. Connection establishment tryout is failed only when the last possible selection has been failed.  
         [0038]     Which one of the above-mentioned alternatives is used can be based for example on the reliability of the service bearer, costs involved, capacity needed or time on hand.  
         [0039]      FIG. 3  illustrates in the form of an exemplary flow chart the main stages of the connection backup method of the present invention. In the beginning a wireless terminal  14  is in a standby mode or idle state. The connection establishment procedure starts in phase  310  where a need for connection is detected. In the next step, reference sign  311 , is checked which connection parameter settings, which correspond to available service bearers, have been implemented in the wireless modem. It is also checked which one of them at present is the default one.  
         [0040]     The connecting setup starts with the default connection parameter setting, phase  312 . Next in a first comparison phase  320  is checked if the attempt made in phase  312  was successful or not. If it was successful, the process ends in phase  390  where the actual data transfer between the remote application  15  and the controlling application  13  in the INTRANET  12  takes place.  
         [0041]     It is also possible that in the beginning of the above-mentioned connection attempt in phase  312  the serving network sends immediately a message, for example an error code, which ends immediately the attempt underway. In this situation the process goes directly to phase  370  where an indication is given that the connection attempt has been failed (not shown in  FIG. 3 ). After that the process moves to exit phase  385  and the process ends without any successful connection.  
         [0042]     After disconnection of the data transmission in phase  390  a default connection parameter setting will always be defined for the next connection establishment attempt. There are several alternatives: First the original default parameter setting can be restored if it has been changed. Second alternative is that the used connection parameter setting can be set as a new default one. A third alternative is that after a predetermined time the original connection parameter setting is restored. Until that, the last used connection parameter setting is used as a default one. Which of the above-mentioned options will be used depends on the configuration of the M2M terminal/module.  
         [0043]     If the first comparison in phase  320  gives a negative result, the process proceeds to a second comparison phase  330 . There it is checked, whether a new connection setup attempt with the same connection parameter setting is allowed or not. One of the decision criteria used in this phase  330  is the number of allowed tryouts for a certain connection parameter setting. If a new tryout is allowed, the process returns to phase  311  and the above described sequence recurs. In that case a new connection attempt starts again in phase  311  with the same connection parameter setting as earlier.  
         [0044]     If the comparison in second comparison phase  330  gives a negative result, which means that the default connection parameter setting cannot be used anymore, the process continues in a third comparison phase  340 . In the third comparison it is checked if there is a backup connection parameter setting according to the invention left. If the third comparison gives a negative answer it means that the intended connection cannot be established and the process proceeds via phase  370  to exit phase  385 .  
         [0045]     If the comparison in third comparison phase  340  gives a positive result, the process continues to a fourth comparison phase  350 . In fourth comparison phase  350  it is checked if the backup connection parameter setting can be used or not. Which one of the possible backup connection parameter settings is used in this phase can be defined for example by a counter, which is incremented every time when a transition from third comparison phase  340  to fourth comparison phase  350  occurs.  
         [0046]     If the comparison in fourth comparison phase  350  gives a positive result the process continues to phase  360 . In phase  360  the alternative backup connection parameter setting replaces the earlier one, which did not succeed to open wanted communication channel. After phase  360  a new attempt starts in phase  311  and the process continues in above described manner.  
         [0047]     If the comparison in fourth comparison phase  350  gives a negative result, which means that the alternative backup connection parameter setting cannot be used for some reason, the process branches via phase  370  to the exit phase  385 .  
         [0048]     In the exit phase  385  it is noticed that the connection establishment has been failed definitively. In that case the process ends in phase  385  without any successful data transfer, which then typically results in a notification to the remote application  15 .  
         [0049]     For example following reasons can result in the exit phase  385 . If the remote application  15  is embedded in a moving unit, for example in a container, the unit can end up in an area where no service operator, which the wireless terminal is aware of, provides a service. It is also possible that a moving unit ends up in place where it is surrounded by conducting materials as the case may be in a bay of a ship. A telecommunication connection is not possible in either case.  
         [0050]     The unwanted exit phase  385  can cause that a new connection establishment attempt is made after some predetermined time. This unwanted situation, i.e. no connection established after several connection attempts, can recur for a number of times. In this situation it is possible that the remote application  15  sets a time limit to the wireless terminal  24   a  or  24   b  when a new attempt will be allowed. This time limit can also be configured to the wireless terminal as a default during the implementation of the terminal.  
         [0051]     It is also possible that, if the connection establishment attempts do not end with a successful connection, the wireless terminal is allowed to reset its functions. The wireless terminal can do it at once or after a predetermined time. It is also possible that the remote application  15  gives a reset order. After the reset of the wireless terminal  24   a ,  24   b  a new connection establishment attempt can be made. If the connection attempt is not successful, a new reset is possible. However, advantageously the time after which a new reset is allowed is always longer than the time lapsed between last two preceding reset attempts.  
         [0052]     Above mentioned phases can be fulfilled by appropriate software means, i.e. a computer program, which is installed in the wireless terminal  24   a ,  24   b . The computer program can be implemented for example by Java language.  
         [0053]      FIG. 4  shows, as an example, main parts of a wireless terminal  40  employing the method according to the invention. The terminal  40  utilizes an antenna  41  in transmitting and receiving messages. Reference designator  42  represents the means constituting a receiver RX by which the wireless terminal  40  receives messages from the supporting cellular network. The receiver RX comprises the means according to the prior art for all received messages.  
         [0054]     Reference designator  43  represents the means that constitute a transmitter TX in the wireless terminal  40 . The transmitter  43  performs on the signal to be transmitted all the necessary signal processing measures required when communicating with the supporting cellular network.  
         [0055]     From the point of view of the invention the crucial functional unit in the terminal  40  is the control unit  44 , which controls the operation of the wireless terminal. The control logic  242  or  242   a , as depicted in  FIG. 2   a  or  2   b , can be part of the control unit  44  of the terminal  40 . In this arrangement according to the invention the control unit  44  determines after each connection establishment request which one of the possible connection parameter settings, i.e. the service bearers, will be used. The control unit  44  uses in the deduction process a computer program according to the invention, which carries out the steps depicted in  FIG. 3 . The computer program required by the control unit  44  in the operation according to the invention advantageously resides in a memory unit  45 . Also the connection parameter settings  241  or  241   a  and operator list  241   b  can be saved in the memory  45  of the terminal  40 .  
         [0056]     The control unit  44  is further used to control an application interface API  46  of the terminal  40 . The remote application  15  can be connected, reference signs  151 ,  152  and  153 , to the application interface  46 . Data can be transferred to or from the remote application  15  by fixed connections  151  and  152 . A third connection  153  illustrates a possibility to give commands to the wireless terminal  40 , for example a reset command.  
         [0057]     Some advantageous embodiments according to the invention were described above. The invention is not limited to the embodiments described. The inventional idea can be applied in numerous ways within the scope defined by the claims attached hereto.