Patent Publication Number: US-2012044865-A1

Title: Apparatus And Method For Coupling An M2M Device To A Wireless Network

Description:
RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from U.S. Provisional Patent Application No. 61/375,506, filed Aug. 20, 2010, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to apparatus and method for coupling a machine-to-machine (M2M) device to a wireless network operating in accordance with a communication standard. 
     BACKGROUND 
     A machine-to-machine (M2M) system, also known as a machine-type-communication (MTC) system, is a communication system that enables a flow of data, e.g., monitored data, from machine to machine and/or from machine to human with minimal human interaction. An example of the M2M system is a security system or a surveillance system. 
       FIG. 1  illustrates a block diagram of a conventional M2M system  100 . Referring to  FIG. 1 , the system  100  includes one or more M2M devices  102 , an M2M server  104 , and a wireless network  106  provided by a service provider that may cover a large number of M2M devices. The M2M devices  102  may be used in different applications including, e.g., electricity, water, or gas consumption monitoring, remote health monitoring, etc. The M2M devices  102  are configured to send monitored data through the wireless network  106  to the M2M server  104  for further processing or analysis. 
     Typically, the wireless network  106  operates in accordance with a wireless communication standard, such as a 3rd Generation Partnership Project (3GPP) standard. Currently, however, the wireless network  106  configured to operate in accordance with the 3GPP standard may communicate with those M2M devices that are directly connected using a 3GPP interface. 
     SUMMARY 
     According to a first aspect of the present disclosure, there is provided apparatus for coupling one or more machine-to-machine (M2M) devices to a wireless network, comprising: a first network interface controller (NIC) module configured to communicate with the M2M devices; an M2M controller unit coupled to the first NIC module, the M2M controller unit including a database and a controller, the controller being configured to store information regarding the M2M devices in the database and to retrieve information regarding the M2M devices from the database; and a second NIC module coupled to the M2M controller unit, the second NIC module including an M2M enable unit configured to send the information retrieved by the controller to the wireless network. 
     According to a second aspect of the present disclosure, there is provided a method for a gateway to couple one or more machine-to-machine (M2M) devices to a wireless network, comprising: communicating with the M2M devices; storing information regarding the M2M devices in a database and retrieving information regarding the M2M devices from the database; and sending the retrieved information to the wireless network. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  illustrates a block diagram of a conventional machine-to-machine (M2M) system. 
         FIG. 2A  illustrates a block diagram of an M2M system, according to an exemplary embodiment. 
         FIG. 2B  illustrates a block diagram of an M2M gateway, according to an exemplary embodiment. 
         FIG. 3  illustrates a process for an M2M gateway to send initial information regarding M2M devices to a 3GPP network, according to an exemplary embodiment. 
         FIG. 4  shows a flowchart of a method for an M2M controller unit to provide updated information regarding M2M devices to a 3GPP network interface controller module in an M2M gateway, according to an exemplary embodiment. 
         FIG. 5  shows a flowchart of a decision making process performed by an M2M enable unit in an M2M gateway, according to an exemplary embodiment. 
         FIG. 6  illustrates a process for an M2M gateway to decide on sending updated information regarding M2M devices to a 3GPP network, according to an exemplary embodiment. 
         FIG. 7  illustrates a process for an M2M gateway to decide on sending updated information regarding M2M devices to a 3GPP network, according to an exemplary embodiment. 
         FIG. 8  illustrates a process for an M2M gateway to decide on sending updated information regarding M2M devices to a 3GPP network, according to an exemplary embodiment. 
         FIG. 9  illustrates a process for an M2M gateway to send updated information regarding M2M devices to a 3GPP network, according to an exemplary embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the invention. Instead, they are merely examples of systems and methods consistent with aspects related to the invention as recited in the appended claims. 
       FIG. 2A  illustrates a block diagram of a machine-to-machine (M2M) system  200 , according to an exemplary embodiment. Referring to  FIG. 2A , the system  200  includes one or more M2M devices  202 , an M2M gateway  204 , a wireless network  206  operating in accordance with a communication standard, and at least one M2M server  208 . For illustrative purposes, it is assumed that the wireless network  206  operates in accordance with the 3rd Generation Partnership Project (3GPP) standard, and is therefore a 3GPP network. 
     In exemplary embodiments, the M2M devices  202  may each be a monitoring device for monitoring data to be sent to the M2M server  208  for further processing or analysis. The M2M devices  202  may be used in different applications including, e.g., electricity, water, or gas consumption monitoring, remote health monitoring, etc. In addition, the M2M devices  202  may be grouped as one or more groups of M2M devices based on common features, locations, etc., which may allow the M2M devices  202  to share common subscription with the 3GPP network  206 . The M2M devices  202  may each be connected to the M2M gateway  204  through a wired interface, or a wireless interface, such as a WiFi interface, a Bluetooth interface, a Zigbee interface, a radio-frequency identification (RFID) interface, etc. 
     In exemplary embodiments, the M2M gateway  204  is configured to couple the M2M devices  202  to the 3GPP network  206 . The M2M gateway  204  may include one or more of the following components: a processor configured to execute computer program instructions to perform various processes and methods disclosed herein, random access memory (RAM) and read only memory (ROM) configured to access and store information and computer program instructions, storage to store data and information, databases to store tables, lists, or other data structures, I/O devices, network interfaces, antennas, etc. Further detail of the M2M gateway  204  will be described below. 
     In exemplary embodiments, the 3GPP network  206  is a wireless communication network provided by a service provider that operates in accordance with the 3GPP standard. For example, the 3GPP network  206  includes at least one base station (BS)  206 - 1 , also known as the eNodeB. When the M2M gateway  204  is located within a coverage area of the base station  206 - 1 , the base station  206 - 1  may communicate with the M2M gateway  204 . In addition, the base station  206 - 1  may also communicate with user terminals (not shown) located in the 3GPP network  206 . 
     In exemplary embodiments, the 3GPP network  206  may also include the following components (not shown): a new mobility management entity (MME) that the M2M gateway  204  is to communicate with, an old MME or serving GPRS Support Node (SGSN) that the M2M gateway  204  previously communicated with, a serving gateway (GW), a packet data network (PDN) GW, a policy and charging rules function (PCRF), and a home subscriber server (HSS). Each of these components is defined in the 3GPP standard and will not be explained further. 
     In exemplary embodiments, the M2M server  208  is configured to communicate with the 3GPP network  206 . For example, the M2M server  208  may receive monitored data from the M2M devices  202  through the 3GPP network  206 . Also for example, the M2M server  208  may send control information to the M2M devices  202  through the 3GPP network  206 . 
       FIG. 2B  illustrates a block diagram of the M2M gateway  204  ( FIG. 2A ), according to an exemplary embodiment. Referring to  FIGS. 2A and 2B , the M2M gateway  204  includes a non-3GPP network interface controller (NIC) module  210  for communicating with the M2M devices  202 , a 3GPP NIC module  212  for communicating with the 3GPP network  206 , and a core module  214  coupled to the non-3GPP NIC module  210  and the 3GPP NIC module  212 . Each of the non-3GPP NIC module  210 , the 3GPP NIC module  212 , and the core module  214  may be implemented with hardware and/or software. 
     In exemplary embodiments, the non-3GPP NIC module  210  is configured to communicate with the M2M devices  202  using one or more non-3GPP interfaces, such as a WiFi interface, a Bluetooth interface, a Zigbee interface, and an RFID interface. 
     In exemplary embodiments, the core module  214  includes an M2M controller unit  221 , which further includes a database  222  and a controller  224 . The controller  224  stores information regarding the M2M devices  202  in the database  222  and retrieves information regarding the M2M devices  202  from the database  222 . The core module  214  also includes a memory manager  226  to manage memory usage by the database  222 , and a communication scheduler  228  to schedule communications between the M2M gateway  204  and the M2M devices  202  and communications between the M2M gateway  204  and the 3GPP network  206 . 
     In exemplary embodiments, the 3GPP NIC module  212  includes, apart from a standard 3GPP protocol stack, an M2M enable unit  220  configured to enable control and monitoring of the M2M devices  202  through the 3GPP network  206 . For example, the M2M enable unit  220  may send initial information regarding the M2M devices  202  to the 3GPP network  206  based on, e.g., as part of, an initial attach process provided in the 3GPP standard. Also for example, the M2M enable unit  220  may send, periodically or non-periodically, updated information regarding the M2M devices  202  to the 3GPP network  206  based on a Tracking Area Update (TAU) process provided in the 3GPP standard. As a result, the M2M gateway  204  enables the 3GPP network  206  to manage and monitor non-3GPP M2M devices and to update an MME database of the 3GPP network  206  with the initial or updated information regarding the M2M devices  202 , as described in detail below. 
       FIG. 3  illustrates a process  300  for the M2M gateway  204  ( FIG. 2A ) to send initial information regarding the M2M devices  202  ( FIG. 2A ) to the 3GPP network  206  ( FIG. 2A ), according to an exemplary embodiment. Referring to  FIGS. 2A and 3 , during the process  300 , the M2M gateway  204  registers with the 3GPP network  206 . In the exemplary embodiment, the process  300  is based on an initial attach process provided in the 3GPP standard. 
     As described above, the 3GPP network  206  may include the base station (BS)  206 - 1 , the new MME, the old MME/SGSN, the serving GW, the PDN GW, the PCRF, and the HSS. The M2M enable unit  220  ( FIG. 2B ) in the M2M gateway  204  initiates the process  300  by sending an attach request to the base station  206 - 1  ( 302 ). The attach request includes initial information regarding the M2M devices  202 , e.g., one or more group identifications for the M2M devices  202  as one or more groups, respectively, a number of the M2M devices  202  in each of the groups and/or connected to the M2M gateway  204 , a list of individual identifications of the respective M2M devices  202 , and/or M2M features. For example, the M2M features may be low volume data transmission or low mobility M2M monitoring. 
     Next, the new MME performs authentication of the M2M gateway  204  ( 304 ), and sends a delete-session request to the serving GW, to terminate any previous communication session between the M2M gateway  204  and the old MME/SGSN ( 306 ). As a result, the previous communication session is terminated, and the PDN GW indicates to the PCRF that resources for the previous communication session have been released ( 308 ). 
     The new MME further sends a create-session request to the serving GW ( 310 ). In response, the serving GW creates a new communication session for the M2M gateway  204 , working together with the PDN GW, the PCRF, and/or the HSS ( 312 ). The serving GW also sends a create-session response to the new MME to indicate the creation of the new communication session ( 314 ). 
     The new MME then updates its database to include the initial information regarding the M2M devices  202  ( 316 ), and sends an attach-accept message to the base station  206 - 1  ( 318 ). The base station  206 - 1  then reconfigures the M2M gateway  204  by sending a radio resource control (RRC) connection reconfiguration message, which includes the attach-accept message, to the M2M gateway  204  ( 320 ). When the reconfiguration is finished, the M2M gateway  204  sends a direct-transfer message to the base station  206 - 1 , to indicate that the attach process is completed ( 322 ). The base station  206 - 1  further sends an attach-complete message to notify the new MME ( 324 ). As a result, the M2M gateway  204  enables the 3GPP network  206  to update its MME database with the initial information regarding the M2M devices  202 , and establishes communications with the 3GPP network  206 . 
     Referring to  FIG. 2A , in exemplary embodiments, a status of the M2M devices  202  may change. For example, the status change may include a new M2M device being added into the M2M devices  202 , or an existing M2M device being removed from the M2M devices  202 . Also for example, the status change may include any one of the M2M devices  202  changing its operation mode, e.g., changing from an idle mode to a power saving mode. 
     In exemplary embodiments, the M2M gateway  204  may obtain updated information regarding the M2M devices  202  through the non-3GPP network interfaces of the M2M devices  202 . The M2M gateway  204  may further send the updated information regarding the M2M devices  202  to the 3GPP network  206 . 
       FIG. 4  shows a flowchart of a method  400  for the M2M controller unit  221  ( FIG. 2B ) to provide updated information regarding the M2M devices  202  ( FIG. 2A ) to the 3GPP NIC module  212  ( FIG. 2B ) in the M2M gateway  204  ( FIG. 2A ), according to an exemplary embodiment. Referring to  FIGS. 2A ,  2 B, and  4 , the controller  224  in the M2M controller unit  221  determines an event classification for a status change in the M2M devices  202 , e.g., a join event indicating that a new M2M device joins the M2M devices  202 , a leave event indicating that an existing M2M device leaves the M2M devices  202 , or an update event indicating that the operation mode of any one of the M2M devices  202  changes ( 402 ). 
     If the controller  224  determines that a new M2M device joins the M2M devices  202  ( 402 —Join), the controller  224  updates the database  222  by adding a new entry in the database  222 , the new entry including information regarding the new M2M device, e.g., an individual identification of the new M2M device ( 404 ). If the controller  224  determines that an existing M2M device leaves the M2M devices  202  ( 402 —Leave), the controller  224  updates the database  222  by deleting an entry corresponding to the leaving device from the database  222  ( 406 ). If the controller  224  determines that the operation mode of any one of the M2M devices  202  changes ( 402 —Update), the controller  224  updates the database  222  by updating the entry corresponding to that device ( 408 ). 
     The controller  224  further increases an update counter by one ( 410 ), and determines if the update counter reaches a predetermined threshold ( 412 ), i.e., determines if a predetermined number of updates have been made to the database  222 . If the controller  224  determines that the update counter has not reached the predetermined threshold ( 412 —No), the process is complete. Otherwise ( 412 —Yes), the controller  224  sends an M2M devices status update request to the 3GPP NIC module  212  ( 414 ), and resets the update counter ( 416 ). 
     The M2M enable unit  220  in the 3GPP NIC module  212  receives the M2M devices status update request from the controller  224 . In addition, the M2M enable unit  220  may receive an M2M devices status update request from the 3GPP network  206 . Further, the M2M gateway  204  itself may periodically send updated information regarding the M2M devices  202  to the 3GPP network  206 . 
     In exemplary embodiments, the M2M enable unit  220  may decide to send updated information regarding the M2M devices  202  to the 3GPP network  206  based on the above situations.  FIG. 5  shows a flowchart of a decision making process  500  performed by the M2M enable unit  220 , according to an exemplary embodiment. 
     Referring to  FIGS. 2A ,  2 B, and  5 , the M2M enable unit  220  determines if it has received an M2M devices status update request from the M2M controller unit  221  ( 502 ). If the M2M enable unit  220  determines that it receives an M2M devices status update request from the M2M controller unit  221  ( 502 —Yes), the M2M enable unit  220  retrieves current information regarding the M2M devices  202  from the database  222  ( 504 ). 
     If the M2M enable unit  220  determines that it has not received an M2M devices status update request from the M2M controller unit  221  ( 502 —No), the M2M enable unit  220  further determines if a timer used by the gateway  204  to periodically send updated information to the 3GPP network  206  has expired ( 506 ). For example, the 3GPP standard provides a Tracking Area Update (TAU) process in which a terminal in a 3GPP network may periodically update its information with the 3GPP network according to a timer. When the timer runs for a predetermined time period, the terminal initiates the TAU process to update its information with the 3GPP network. 
     If the M2M enable unit  220  determines that the timer has expired ( 506 —Yes), the M2M enable unit  220  retrieves current information regarding the M2M devices  202  from the database  222  ( 504 ). Otherwise ( 506 —No), the M2M enable unit  220  further determines if it has received an M2M devices status update request from the 3GPP network  206  ( 508 ). If the M2M enable unit  220  determines that it has received an M2M devices status update request from the 3GPP network  206  ( 508 —Yes), the M2M enable unit  220  also retrieves current information regarding the M2M devices  202  from the database  222  ( 504 ). The M2M enable unit  220  further configures a message, referred to herein as a TAU request, including the updated information regarding the M2M devices  202 , and sends the TAU request to the 3GPP network  206  ( 510 ). The M2M enable unit  220  then resets the timer ( 512 ). If the M2M enable unit  220  determines that it has not received an M2M devices status update request from the 3GPP network  206  ( 508 —No), the M2M enable unit  220  performs a normal TAU decision process defined in the 3GPP standard ( 514 ). 
       FIG. 6  illustrates a process  600  for the M2M gateway  204  ( FIG. 2A ) to decide on sending updated information regarding the M2M devices  202  ( FIG. 2A ) to the 3GPP network  206  ( FIG. 2A ), according to an exemplary embodiment. Referring to  FIGS. 2A ,  2 B, and  6 , the non-3GPP NIC module  210  reports to the controller  224  a status change in the M2M devices  202 , e.g., a new M2M device joining the M2M devices  202 , an existing M2M device leaving the M2M devices  202 , or a change in the operation mode of any one of the M2M devices  202  ( 602 ). Accordingly, the controller  224  updates the database  222  ( 604 ), and increases the update counter by one, as described above. This process may be repeated until the update counter reaches the predetermined threshold ( 606 ). 
     The controller  224  then sends an M2M devices status update request to the M2M enable unit  220  in the 3GPP NIC module  212  ( 608 ). In response, the M2M enable unit  220  sends an M2M devices status update trigger to the controller  224  ( 610 ), and the controller  224  retrieves current information regarding the M2M devices  202  from the database  222  in response to the M2M devices status update trigger ( 612 ). The controller  224  then sends an M2M devices status update report including the current information regarding the M2M devices  202  to the M2M enable unit  220  ( 614 ). The M2M enable unit  220  further processes the M2M devices status update request by sending updated information regarding the M2M devices  202  to the 3GPP network  206  ( 616 ), and sends an M2M devices status update acknowledgement to the controller  224  ( 618 ). 
       FIG. 7  illustrates a process  700  for the M2M gateway  204  ( FIG. 2A ) to decide on sending updated information regarding the M2M devices  202  ( FIG. 2A ) to the 3GPP network  206  ( FIG. 2A ), according to an exemplary embodiment. Referring to  FIGS. 2A ,  2 B, and  7 , when the timer used by the gateway  204  to periodically send updated information to the 3GPP network  206  expires ( 702 ), the M2M enable unit  220  sends an M2M devices status update trigger to the controller  224  ( 704 ), and the controller  224  retrieves current information regarding the M2M devices  202  from the database  222  in response to the M2M deices status update trigger ( 706 ). The controller  224  then sends an M2M devices status update report including the current information regarding the M2M devices  202  to the M2M enable unit  220  ( 708 ). The M2M enable unit  220  further processes the M2M devices status update request by sending updated information regarding the M2M devices  202  to the 3GPP network  206  ( 710 ), and sends an M2M devices status update acknowledgement to the controller  224  ( 712 ). 
       FIG. 8  illustrates a process  800  for the M2M gateway  204  ( FIG. 2A ) to decide on sending updated information regarding the M2M devices  202  ( FIG. 2A ) to the 3GPP network  206  ( FIG. 2A ), according to an exemplary embodiment. Referring to  FIGS. 2A ,  2 B, and  8 , when the M2M enable unit  220  receives an M2M devices status request from the 3GPP network  206  ( 802 ), the M2M enable unit  220  sends an M2M devices status update trigger to the controller  224  ( 804 ), and the controller  224  retrieves current information regarding the M2M devices  202  from the database  222  in response to the M2M devices status update trigger ( 806 ). The controller  224  then sends an M2M devices status update report including the updated information regarding the M2M devices  202  to the M2M enable unit  220  ( 808 ). The M2M enable unit  220  further processes the M2M devices status update request by sending updated information regarding the M2M devices  202  to the 3GPP network  206  ( 810 ), and sends an M2M devices status update acknowledgement to the controller  224  ( 812 ). 
     As a result, the M2M gateway  204  may periodically, or non-periodically such as based on a condition which may not occur at periodic intervals, send updated information regarding the M2M devices  202  to the 3GPP network  206 . As described above, the 3GPP standard provides a Tracking Area Update (TAU) process in which a terminal in a 3GPP network periodically updates its information with the 3GPP network according to a timer and defined conditions. In the exemplary embodiment, the M2M gateway  204  periodically or non-periodically sends updated information regarding the M2M devices  202  to the 3GPP network  206  based on the TAU process provided in the 3GPP standard. 
       FIG. 9  illustrates a process  900  for the M2M gateway  204  ( FIG. 2A ) to send updated information regarding the M2M devices  202  ( FIG. 2A ) to the 3GPP network  206  ( FIG. 2A ) based on the TAU process, according to an exemplary embodiment. Referring to  FIGS. 2A and 9 , the M2M gateway  204  is triggered, or decides, to start the process  900  as described in  FIG. 6 ,  7 , or  8  ( 902 ). The M2M gateway  204  sends a TAU request to the new MME through the base station ( 904 ). The TAU request includes updated information regarding the M2M devices  202 , e.g., one or more group identifications for the M2M devices  202  as one or more groups, respectively, a number of the M2M devices  202  in each of the groups and/or connected to the M2M gateway  204 , a list of individual identifications of the respective M2M devices  202 , or M2M features. 
     Next, the new MME sends a context request to the old MME/SGSN, to request context information regarding the M2M gateway  204  ( 906 ), and further sends a modify-bearer request to the serving GW to modify evolved packet system (EPS) bearers ( 908 ). An EPS bearer is a transmission channel through an EPS packet network which may have a defined set of data transmission characteristics such as quality of service data rate and flow control. Accordingly, the EPS bearers and, hence, the current communication session are modified ( 910 ), and the HSS sends a cancel-location message to the old MME ( 912 ), to ask the old MME to delete all bearer resources of the M2M gateway  204  ( 912 ). 
     Next, the new MME updates its database to include the updated information regarding the M2M devices  202  ( 914 ). The new MME further sends a TAU-accept message to the M2M gateway  204  to indicate an acceptance of the TAU request ( 916 ), and the M2M gateway  204  responds to indicate completion of the information update for the M2M devices  202  ( 918 ). 
     While embodiments have been described based on the 3GPP network, the invention is not so limited. It may be practiced with equal effectiveness with other wireless networks operating in accordance with a communication standard, such as a wireless network operating in accordance with a Worldwide Interoperability for Microwave Access (WiMAX) standard. 
     Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. The scope of the invention is intended to cover any variations, uses, or adaptations of the invention following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. 
     It will be appreciated that the present invention is not limited to the exact construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. It is intended that the scope of the invention only be limited by the appended claims.