Abstract:
A method of network-directed service status order at a mobile station, includes the steps of: (a) from the mobile station sending an origination message, over the network, requesting a service with the network; (b) in response to the origination message, at the mobile station receiving over the network a status message of a status of the requested service, the status message identifying one of a grant of the requested service and a denial of the requested service; and (c) operating the mobile station in an unambiguous state in accordance with the received status message.

Description:
CROSSREFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of International Patent Application PCT/CA2004/000738, entitled Apparatus and Method of Determining the Status of a Requested Service, filed May 14, 2004, and claims priority from European Patent Application 03252988.5, filed May 14, 2003, the contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This application relates to mobile communication techniques in general, and to an apparatus and method of network-directed service status in particular.  
       BACKGROUND OF THE INVENTION  
       [0003]     In known code division multiple access (CDMA) based networks, a base station (BS) may send a Release Order on Paging Channel (PCH) to a mobile station (MS) to indicate a variety of things. However, the MS can&#39;t unambiguously decide what the intention of Release Order really is, except perhaps for the Service Option Reject Release Order as specified in IS-2000.5. The Release on PCH is typically sent to save network resources e.g. when the network deems that there is no need to allocate traffic channel resources. If the intention of the release order is not clear enough to the MS, then it may not serve the intended purpose. In some cases, it may make things even worse e.g. MS may initiate retry efforts which defeats the purpose of the Release on PCH.  
         [0004]     Two examples of the problem described above may be observed on current CDMA-based networks.  
         [0005]     First, if mobile-originated (MO) short messaging service (SMS) is not allowed and the MS makes an origination attempt indicating SMS service option, then the BS sends release order on PCH without granting traffic channel. This would be the case when MS is not provisioned for MO SMS or when the MS moves to a foreign network that does not allow it to send SMS. However, the MS is unable to determine the actual cause of release from the received information and may even retry a number of times. In addition, MS may not be able to show the exact reason for the failure to the user.  
         [0006]     Second, a packet data capable MS is required to “reconnect” its dormant session whenever there is a change in System identifier (SID), Network Identifier (NID), or Packet zone Identifier (PID) as specified in IS-707. If the MS simply crosses the BS boundary, but is still within the scope of serving Packet Data Service Node (PDSN), then there is no need to renegotiate the point-to-point protocol (PPP) connectivity. When the MS sends packet data origination with (Data Ready To Send) DRS field set to 0 (i.e. MS has no real data to send), the BS, as per some implementations, may send Release Order on PCH while with other implementations, the BS will bring the MS all the way to traffic state just to indicate that the reconnect was successful. In the occasion when Release order is sent in PCH without any given reason, the MS cannot be certain that the release was meant as a positive indication that the reconnect was successful. The Network (e.g. a foreign one with no data roaming agreement) can also send release order to deny service. It is of utmost importance for an always-on always-connected MS to be able to unambiguously determine the intent of a release order. Otherwise, the MS will be forced to figure out the intention (which in turn triggers subsequent packet data origination) whether PPP connectivity is still there or not.  
         [0007]     When reconnects are brought all the way to traffic state, just to mean that the attempt was successful, this may waste traffic channel resources, and cause undesired battery drainage due to traffic state.  
       SUMMARY OF THE INVENTION  
       [0008]     According to a first aspect of the invention, there is provided a method of communicating over a communications network with a mobile station. The method involves the steps of: (a) from the mobile station sending an origination message, over the network, requesting a service with the network; (b) in response to the origination message, at the mobile station receiving over the network an indication of a status of the service request, the status indication being one of a grant of the requested service and a denial of the requested service ; and (c) operating the mobile station in an unambiguous state in accordance with the received service request indication.  
         [0009]     In one implementation, the service request indication receiving step involves receiving the service request indication over a control channel of the network, such as a paging channel. The origination message sending step involves sending the origination message from either a dormant state or an idle state of the mobile station. The origination message sending step may also involve at the mobile station detecting a change in a network parameter, and sending the origination message from the one state in response to the detected change.  
         [0010]     The service status indication may comprise a release order message having a service order qualifier code, such that the service status order qualifier identifies the service grant or the service denial. Further, the service status order qualifier may identify the service denial and a reason for the service denial.  
         [0011]     The requested service may be a circuit-switched service, or a packet data service.  
         [0012]     According to a second aspect of the invention, there is provided a mobile station for communicating over a CDMA network. The mobile station includes a service call state machine that is configured to perform the steps of: (a) facilitating transmission over the network of an origination message requesting a service with the network, by transitioning from an originating state from which the transmission is initiated to a service state associated with the requested service ; (b) in the service state, receiving over the network, in response to the origination message, an indication of a status of the service request, the status indication being one of a grant of the requested service and a denial of the requested service ; and(c)transitioning from the service state to one of the originating state and a null state in accordance with the received service request indication.  
         [0013]     Other aspects and features of the invention will become apparent to those ordinarily skilled in the art upon review of the following description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     Embodiments of the invention will now be described, by way of example only, with reference to the attached figures, wherein:  
         [0015]      FIG. 1  illustrates an embodiment of an apparatus provided in accordance with the invention;  
         [0016]      FIG. 2  illustrates a packet data service call control state machine provided in accordance with the invention;  
         [0017]      FIG. 3  illustrates a circuit-switched service call control state machine provided in accordance with the invention;  
         [0018]      FIG. 4  is an interaction diagram illustrating the operation of the invention; and  
         [0019]      FIG. 5  is a block diagram illustrating a mobile station according to the invention. 
     
    
       [0020]     Same reference numerals are used in different figures to denote similar elements.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     According to the invention there are provided techniques that may enable Release Order in Paging Channel with ‘meaningful ORDQ’ to unambiguously indicate whether the reconnect was successful or failed. These meaningful types of Release Orders are hereinafter referred to as Service Release orders so as to better differentiate them from known Release Orders.  
         [0022]     Additional order qualification codes (ORDQ) are provided to explicitly indicate the cause of the Service Release Order. The following new ORDQ values are proposed for Release order (ORDER=010101):  
         [0023]     ORDQ=00000100 (indicates that requested ‘service is denied’)  
         [0024]     ORDQ=00000101 (indicates that requested ‘service is granted’)  
         [0025]     The proposed values for the ORDQ parameter are illustrative only, and are not meant to limit the scope of the invention, but includes all alternate values for the ORDQ Release parameter that could be used in a Service Release Order, the selection of which would be apparent to a person of ordinary skill in the art to which this invention. Furthermore, it is envisaged that the actual number assigned to each ORDQ may vary with the version of the CDMA based network in which the invention are used.  
         [0026]     Advantageously, according to the invention, the network is enabled to send a release order with ORDQ=‘service is denied’ when an MS is to be told that the requested service is denied by the network. For successful reconnect in packet data service, the network sends a release order with ORDQ=‘service is granted’ on the paging channel when a MS is to be told that the requested ‘service is granted’.  
         [0027]     Referring to the drawings,  FIG. 1  illustrates an embodiment of an apparatus provided in accordance with the invention. A code division multiple access-based network  100  is provided with a Base Station/Home Location Register BS/HLR  110  adapted to communicate with a mobile station MS  120 . MS  120  includes a service call control state machine  130  having at least one state transition  140  which is triggered by a Service Status Order  150 , such as a Service Release Order which has an ORDQ value equal to one of ‘SERVICE DENIED’and ‘SERVICE GRANTED’.  
         [0028]     It is envisaged that in specific embodiments, the service call control state machine be adapted to the specific requirements of the CDMA based network and mobile stations in which the invention are used. For example, in IS-2000 CDMA based networks and mobile stations that use packet data services, the state machine of  FIG. 2  can be used at the mobile station, whereas in IS-2000 CDMA based networks and mobile stations that use circuit-switched services, the state machine of  FIG. 3  can be used at the mobile station, and in IS-2000 CDMA based networks and mobile stations that use both packet data and circuit-switched services, both the state machines of  FIG. 2  and  FIG. 3  can be provided at the mobile station.  
         [0029]     Turning now to  FIG. 2 ,  FIG. 2  illustrates a packet data service call control state machine provided in accordance with the invention. The state machine  200  includes a dormant state  210 , a reconnect state  220 , a null state  230 , an initialization state  240 , a connected state  250 , and two transitions  221 , 223  which are triggered by Service Status Orders, provided by Release Orders having a service status order qualification code.  
         [0030]     Consider a MS which is initially in dormant state  210 . Then, for example, the MS may need to reconnect when the serving SID, NID or PID has changed, but it may have no data to send. Advantageously, the MS transitions from dormant state  210  to reconnect state  220  via CONNECT NO SEND SERVICE  212  transition. In reconnect state  220 , the MS attempts to reconnect service even though MS has no data to send, for instance by sending an origination request and awaiting for a Service Release Order provided by the network in accordance to the invention.  
         [0031]     Further advantageously, while in reconnect  220  state, upon reception of a Service Release Order, either one of ‘SERVICE GRANTED’  221  or ‘SERVICE DENIED’  223  Service Release Orders on the paging channel, the state transitions from reconnect  220  to one of either dormant  210  or null  230  respectively.  
         [0032]     On one hand, by taking the ‘Service Granted’ transition to reach the dormant state, the MS is enabled to go dormant since the network sent a service release order on the paging channel indicating service is granted. There is no need for the network or the MS to go through the dedicated traffic, such as through transition  245 .  
         [0033]     On the other hand, by taking the ‘Service Denied’  223  transition to reach the null state, the MS is enabled to deactivate packet data since the network sent a service release order on the paging channel indicating service is not granted. If the MS desires to remain always connected, it transitions from the null state  230  to the initialization state  240  via the ESTABLISH DATA SESSION  234  transition, for instance when the serving SID, NID or PID changes. From the initialization state  240 , the state may transition back to null  230  via the SERVICE NOT CONNECTED  243  transition, for example if packet data service is deactivated when the service option is not connected. However, if the packet data service is activated, then the state transitions from initialization  240  to connected  250  via the DEDICATED CHANNEL ASSIGNED AND SERVICE CONNECTED  245  transition. While in the connected  250  state, the MS may go to the dormant  210  state via CALL RELEASED  251  transition, for example if the MS still has no data to send.  
         [0034]     Turning now to  FIG. 3 ,  FIG. 3  illustrates a circuit-switched service call control state machine provided in accordance with the invention. The state machine  300  includes an idle state  310 , a system access origination attempt state  320 , a null state  330 , a dedicated traffic channel conversation state  340 , and two transitions  321 , 323  which are triggered by Service Status Orders, provided by Release Orders having a service status order qualification code.  
         [0035]     Consider a MS which is initially in idle state  310 . Then, for example, the MS may need to originate when the user places a call. Advantageously, the MS transitions from idle state  310  to system access origination state  320  via CONNECT SERVICE  312  transition. In system access origination attempt state  320 , the MS attempts to originate service, for instance by sending an origination request and awaiting for a Service Status Order provided in a Release Order having a service status order qualification code in accordance with the invention.  
         [0036]     Further advantageously, while in system access origination attempt  320  state, upon reception of a Service Release Order, either one of ‘SERVICE GRANTED’  321  or ‘SERVICE DENIED’  323  Service Release Orders, the state transitions from system access origination attempt  320  to one of either idle  310  or null  330  respectively. However, the ‘SERVICE GRANTED’  321  transition will only be taken in the case of circuit-switched data service, whereas the ‘SERVICE DENIED’  323  transition can be taken for all manner of circuit switched service, including but not limited to circuit-switched data service, voice service, and short messaging service (SMS).  
         [0037]     On one hand, by taking the ‘Service Granted’ transition to reach the idle state, for example in the case of circuit-switched data, the MS is enabled to go idle since the network sent a service release order on the paging channel indicating service is granted. This can be advantageous when the MS had no data to send, as this enables the MS to avoid having to the dedicated transition to the traffic channel conversation state  330  prior to the idle state  310  via the channel assigned and service connected transition  324 .  
         [0038]     On the other hand, by taking the ‘Service Denied’ transition to reach the null state, the MS is enabled to deactivate circuit switched service since the network sent a service release order on the paging channel indicating service is not granted. If the MS desires to connect, it transitions from the null state  330  to the idle state  310  via the ACQUIRE A SYSTEM  331  transition, and then transitions to the system access origination state  320  via the CONNECT SERVICE  312  transition when it enters a new system. From the system access origination state  320 , if the circuit switched service is activated, then the state transitions from system access origination attempt state  320  to the dedicated traffic channel conversation state  340  via the CHANNEL ASSIGNED AND SERVICE CONNECTED  324  transition. While in the dedicated traffic channel conversation  340  state, the MS may go to the idle  310  state via CALL RELEASED  341  transition.  
         [0039]     Turning now to  FIG. 4 ,  FIG. 4  is an interaction diagram illustrating the operation of the invention. In the interaction diagram  400 , MS  420  begins in either dormant or idle state  430 . Then, at step  440 , the MS  420  needs to originate, for instance because the SID, NID or PID of the current system has changed, or the user wants to place a call such as using SMS. As a result, an origination message  444  having a service option  442  is sent from MS  420  towards BS/HLR  410 . Depending on the implementation, BS/HLR  410  may or may not send back a layer 2 ACK message  445  having an ACK order  447 , as this ACK may be piggy backed onto the next message. Regardless, at step  460  the BS/HLR verifies the PROTOCOL REVISION number of the MS  420 , for instance by obtaining the PROTOCOL REVISION NUMBER from the origination message  444 . If the PROTOCOL REVISION is greater or equal to a predetermined value, then MS  420  supports the Service Status Order provided according to the invention, and a Service Release Message  475  having a RELEASE SERVICE order  477  is sent  470  while the MS is accessing system  450 . Depending on the implementation, and whether or not layer 2 ACK message  445  was sent, service release message  475  may include piggy back ACK  478 . Upon reception of the service release message  475 , the MS  420  at step  480  determines the service status, i.e. whether the service was granted or released, after which the MS  420  transitions to an unambiguous state  490 , such as the null, idle, or dormant states for example.  
         [0040]     Turning now to  FIG. 5 ,  FIG. 5  is a block diagram illustrating a mobile station including preferred embodiments of the apparatus and method of the current invention. Mobile station  500  is preferably a two-way wireless communication device having at least voice and data communication capabilities. Mobile station  500  preferably has the capability to communicate with other computer systems on the Internet. Depending on the exact functionality provided, the wireless device may be referred to as a data messaging device, a two-way pager, a wireless e-mail device, a cellular telephone with data messaging capabilities, a wireless Internet appliance, or a data communication device, as examples.  
         [0041]     Where mobile station  500  is enabled for two-way communication, it will incorporate a communication subsystem  511 , including both a receiver  512  and a transmitter  514 , as well as associated components such as one or more, preferably embedded or internal, antenna elements  516  and  518 , local oscillators (LOs)  513 , and a processing module such as a digital signal processor (DSP)  520 . As will be apparent to those skilled in the field of communications, the particular design of the communication subsystem  511  will be dependent upon the communication network in which the device is intended to operate. For example, mobile station  500  may include a communication subsystem  511  designed to operate within the Mobitex mobile communication system, the DataTAC™ mobile communication system, GPRS network, UMTS network, EDGE network or CDMA network.  
         [0042]     Network access requirements will also vary depending upon the type of network  519 . For example, in the Mobitex and DataTAC networks, mobile station  500  is registered on the network using a unique identification number associated with each mobile station. In UMTS and GPRS networks, and in some CDMA networks, however, network access is associated with a subscriber or user of mobile station  500 . A GPRS mobile station therefore requires a subscriber identity module (SIM) card in order to operate on a GPRS network, and a RUIM in order to operate on some CDMA networks. Without a valid SIM/RUIM card, a GPRS/UMTS/CDMA mobile station may not be fully functional. Local or non-network communication functions, as well as legally required functions (if any) such as “911” emergency calling, may be available, but mobile station  500  will be unable to carry out any other functions involving communications over the network  500 . The SIM/RUIM interface  544  is normally similar to a card-slot into which a SIM/RUIM card can be inserted and ejected like a diskette or PCMCIA card. The SIM/RUIM card can have approximately 64K of memory and hold many key configuration  551 , and other information  553  such as identification, and subscriber related information.  
         [0043]     When required network registration or activation procedures have been completed, mobile station  500  may send and receive communication signals over the network  519 . Signals received by antenna  516  through communication network  519  are input to receiver  512 , which may perform such common receiver functions as signal amplification, frequency down conversion, filtering, channel selection and the like, and in the example system shown in  FIG. 5 , analog to digital (A/D) conversion. A/D conversion of a received signal allows more complex communication functions such as demodulation and decoding to be performed in the DSP  520 . In a similar manner, signals to be transmitted are processed, including modulation and encoding for example, by DSP  520  and input to transmitter  514  for digital to analog conversion, frequency up conversion, filtering, amplification and transmission over the communication network  519  via antenna  518 . DSP  520  not only processes communication signals, but also provides for receiver and transmitter control. For example, the gains applied to communication signals in receiver  512  and transmitter  514  may be adaptively controlled through automatic gain control algorithms implemented in DSP  520 .  
         [0044]     Mobile station  500  preferably includes a microprocessor  538  which controls the overall operation of the device. Communication functions, including at least data and voice communications, are performed through communication subsystem  511 . Microprocessor  538  also interacts with further device subsystems such as the display  522 , flash memory  524 , random access memory (RAM)  526 , auxiliary input/output(I/O) subsystems  528 , serial port  530 , keyboard  532 , speaker  534 , microphone  536 , a short-range communications subsystem  540  and any other device subsystems generally designated as  542 .  
         [0045]     Some of the subsystems shown in  FIG. 5  perform communication-related functions, whereas other subsystems may provide “resident” or on-device functions. Notably, some subsystems, such as keyboard  532  and display  522 , for example, may be used for both communication-related functions, such as entering a text message for transmission over a communication network, and device-resident functions such as a calculator or task list.  
         [0046]     Operating system software used by the microprocessor  538  is preferably stored in a persistent store such as flash memory  524 , which may instead be a read-only memory (ROM) or similar storage element (not shown). Those skilled in the art will appreciate that the operating system, specific device applications, or parts thereof, may be temporarily loaded into a volatile memory such as RAM  526 . Received communication signals may also be stored in RAM  526 .  
         [0047]     As shown, flash memory  524  can be segregated into different areas for both computer programs  558  and program data storage  550 ,  552 ,  554  and  556 . These different storage types indicate that each program can allocate a portion of flash memory  524  for their own data storage requirements. Microprocessor  538 , in addition to its operating system functions, preferably enables execution of software applications on the mobile station. A predetermined set of applications that control basic operations, including at least data and voice communication applications for example, will normally be installed on mobile station  500  during manufacturing. A preferred software application may be a personal information manager (PIM) application having the ability to organize and manage data items relating to the user of the mobile station such as, but not limited to, e-mail, calendar events, voice mails, appointments, and task items. Naturally, one or more memory stores would be available on the mobile station to facilitate storage of PIM data items. Such PIM application would preferably have the ability to send and receive data items, via the wireless network  519 . In a preferred embodiment, the PIM data items are seamlessly integrated, synchronized and updated, via the wireless network  519 , with the mobile station user&#39;s corresponding data items stored or associated with a host computer system. Further applications may also be loaded onto the mobile station  500  through the network  519 , an auxiliary I/O subsystem  528 , serial port  530 , short-range communications subsystem  540  or any other suitable subsystem  542 , and installed by a user in the RAM  526  or preferably a non-volatile store (not shown) for execution by the microprocessor  538 . Such flexibility in application installation increases the functionality of the device and may provide enhanced on-device functions, communication-related functions, or both. For example, secure communication applications may enable electronic commerce functions and other such financial transactions to be performed using the mobile station  500 .  
         [0048]     In a data communication mode, a received signal such as a text message or web page download will be processed by the communication subsystem  511  and input to the microprocessor  538 , which preferably further processes the received signal for output to the display  522 , or alternatively to an auxiliary I/O device  528 . A user of mobile station  500  may also compose data items such as email messages for example, using the keyboard  532 , which is preferably a complete alphanumeric keyboard or telephone-type keypad, in conjunction with the display  522  and possibly an auxiliary I/O device  528 . Such composed items may then be transmitted over a communication network through the communication subsystem  511 .  
         [0049]     For voice communications, overall operation of mobile station  500  is similar, except that received signals would preferably be output to a speaker  534  and signals for transmission would be generated by a microphone  536 . Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on mobile station  500 . Although voice or audio signal output is preferably accomplished primarily through the speaker  534 , display  522  may also be used to provide an indication of the identity of a calling party, the duration of a voice call, or other voice call related information for example.  
         [0050]     Serial port  530  in  FIG. 5 , would normally be implemented in a personal digital assistant (PDA)-type mobile station for which synchronization with a user&#39;s desktop computer (not shown) may be desirable, but is an optional device component. Such a port  530  would enable a user to set preferences through an external device or software application and would extend the capabilities of mobile station  500  by providing for information or software downloads to mobile station  500  other than through a wireless communication network. The alternate download path may for example be used to load an encryption key onto the device through a direct and thus reliable and trusted connection to thereby enable secure device communication.  
         [0051]     Other communications subsystems  540 , such as a short-range communications subsystem, is a further optional component which may provide for communication between mobile station  500  and different systems or devices, which need not necessarily be similar devices. For example, the subsystem  540  may include an infrared device and associated circuits and components or a Bluetooth communication module to provide for communication with similarly enabled systems and devices.  
         [0052]     When mobile station  500  is used in conjunction with the techniques of  FIGS. 1-4 , the other device subsystems  542  and other components of mobile station  500  embody an apparatus and method of network-directed service status.  
         [0053]     The above-described embodiments of the invention are intended to be examples only of the invention. Those of ordinary skill in the art may envisage alterations, modifications and variations to the described embodiments which do not depart from the scope of the invention, as defined by the appended claims.