Packet data serving node to maintain an always-on wireless internet protocol communication and method thereof

ES 2 261 970 T3

DESCRIPTION

Radio communication by Internet protocol always active.

Technical field

The technology described in this patent document is generally related to the field of point-to-point communication techniques. More in particular, the patent document describes a system and a method for radio communication by Internet protocol (IP) with a mobile station, such as a 2-way paging device, a cell phone, a laptop, or else another type of device suitable for radio communication.

Art Background

Radio IP networks are known in this field. One of these radio networks is described in the “CDMA2000 Radio IP Networks Standard^tm", TIA / IS-835-BTIA / IS-835-B. The CDMA2000 ™ radio IP network uses a link control protocol (LCP) to establish and configure the point-to-point protocol (PPP), which is described in the Request for Comments (RFC) 1661 document. Document EP1148749-A2 discloses a radio network, in which a mobile station has a timer that is always active, which can be greater or less than a "change state" timer located both in the mobile station and in the network. .

Summary of the invention

In accordance with the descriptions set forth herein, a system and a method are defined by independent claims 1 and 29 that are provided for always-on radio IP communication.

Brief description of the drawings

Figure 1 shows an exemplary IP radio communication system, supporting always-on communication with a mobile station;

Figure 2 shows exemplary protocol stacks in different components of Figure 1;

Figure 3 shows a block diagram of an example of an always-on mobile station;

Figure 4 shows a block diagram of an example of an always-on PDSN;

Figure 5 shows a more detailed diagram of the exemplary always-on PDSN network of Figure 4;

Figures 6-8 are flowcharts showing exemplary operation of an always-on mobile station; and FIG. 9 is a flow chart illustrating the operation of an always-on PDSN by way of example. Optimal mode for carrying out the invention

Referring now to the figures of the drawings, Figure 1 shows by way of example a radioelectric IP communication system, which supports always-on communication with the mobile station 10. The communication system includes a provider network 12 (VAPN) an always-on target access network, an always-on serving VAPN 20, a backup network infrastructure 60, 70, 80, and a terminal server 40. Also included in the communication system discussed is an IP network 30, such as the Internet, and a broadband communication network 50, such as the SS7 network.

During operation, the always-on mobile station (MS) 10 communicates through the IP network 30 with the terminal server 40, through at least the always-on VAPN 12,20, cooperating with the standby infrastructure 60, 70, 80. Mobile station 10 is always active in the sense that a packet data session, such as a point-to-point protocol (PPP) session, may be maintained between mobile station 10 and an always-on access provider network ( APN) 12,20,60, while mobile station 10 is idle (for example, it has no data to send or receive). In addition, the PPP session can be maintained during periods when the mobile station 10 has drifted out of coverage, or is temporarily out of communication with the APN 12, 20, which can include periods when the mobile station 10 is served by a network that does not support data communications.

The always-on target VAPN 121 includes a target radio network (RN) 14, and an always-on target packet data service node (PDSN) 16. The always-on service VAPN system 20 includes a source radio network 22 (RN), an always-on service PDSN system 25, a mobile authentication dial-up service (RADIUS) server 24, and a mobile switching center 23 (MSC). Preferably, the

ES 2 261 970 T3 mobile station 10 communicates with the always-on target VAPN 12 system, and then being transferred to the always-on service VAPN 20, for communication with the backup infrastructure 60, 70, 80, and with the terminal server 40. Alternatively, however, the mobile station 10 could communicate with the backup infrastructure directly through the always-on service VAPN system 20.

The always-on target PDSN system 16 and / or the always-on service PDSN system 25 are configured to support always-on service for mobile station 10. The always-on service PDSN 25 cooperates with mobile station 10 through PDSN 16 target system always in service. Alternatively, however, only one of the target PDSN 16 or the serving PDSN 25 may be an always-on PDSN. A detailed description of the always-on service is provided below with reference to Figures 2-9, including the description of the always-on mobile station 10 and the always-on PDSN system 16, 25.

Radio network (RN) 14, 22 may include a base station (or stations) to provide RF communication with mobile station 10 and may also include a packet control function (PCF) to communicate with PDSN system 16 , 25 always active. The communication link between the RN 14, 22 and the PDSN 16, 25 may be an RP interface that uses a GRE tunnel to transport the user packet data and signaling messages between the PCF and the PDSN 16, 25 The communication link between the PDSN target 16 and the serving PDSN system 25, can be a PP interface to carry user data for a single service case, and can be used to support a fast transfer function.

The RADIUS servers 24, 74, 84 located in the service VAPN system 20, initial IP network 74 and the Stockbrokers network 84 are authentication, authorization and accounting (AAA) servers, such as those typically used in CDMA2000 ™ networks, to provide AAA functionality. The initial IP network 70 and the RADIUS server 74 provide IP-based data services to the user of the mobile station so that a network access identifier (NAI) is maintained for the mobile station 10. The network of agents Stockbroker 80 and Stockbroker RADIUS server 84 is an intermediate network / servers that can be used to securely transfer RADIUS messages (eg, AAA information) between VAPNRADIUS server 24 and initial RADIUS server 74. It will be understood that more than one broker RADIUS server 84 may be used to transfer data between the VAPN RADIUD server and the initial RADIUS server 74.

Mobile switching center (MSC) 23 connects source RN 22 to a home location register (HLR) 62 in an home access provider network (APN) 60. Home access provider network 60 is a radio network providing the service area for mobile station 10. It will be understood that the system illustrated in FIG. 1 shows an exemplary operation of the always active mobile station 12, while the mobile station 12 is outside the coverage area of ​​the initial access provider network 62. However, The access provider network 60 preferably includes components similar to the access provider network 12, 20, including a radio network (RN) and an always-on PDSN. Consequently, the always-on service may be always available between the always-on station 12 and the always-on PDSN on the APN 60.

The exemplary IP radio communication system shown in Figure 1 may, for example, be a CDMA2000 ™ radio IP network, which is configured to provide always-on service, as described herein. Additional details regarding the operation of a CDMA2000 ™ radio IP network can be found in the following standard documents (referred to herein as “standards”): TIA / IS-835-B (3GPP2 P.S0001-B), RFC 1661, RFC 2153, TIA / EIA / IS-2000-1 (3GPP2C-S0001-0), TIA / EIA / IS2000-2 (3GPP2 C. S0002-0), TIA / EIA / IS-2000-3 (3GPP2 C.S0003-0), TIA / EIA / IS-2000-4 (3GPP2 C.S20004-0), TIA / EIA / IS-2000-5 (3GPP2 C.S0005-0), TIA / EIA / IS-707 (3GPP2 C.S0017-0), 3GPP2 A.S0001, 3GPP2 A.S0011-0, 3GPP2 A.S0012-0, 3GPP2 A.S0013-0 , 3GPP2 A.S0014-0), 3GPP2 A.S0015-0, 3GPP2 A.S0016-0, 3GPP2 A.S00170, and their revisions.

Figure 2 shows exemplary protocol stacks 110, 122, 125, 140, in different components of the IP-based system of Figure 1. Four protocol stacks 110, 122, 125 are shown, each corresponding respectively to the always-on mobile station (MS) 10, a radio network (RN) 14, 22, an always-on PDSN 16, 25, and the terminal server 40. Protocol stacks 110 and 125 each include Always-On Point-to-Point Protocol (PPP) layers 115 and 130. Layers 115 and 130 of the always-on PPP system cooperate to maintain a PPP session, which enables IP communication between mobile station 10 and server 40 despite lack of coverage or similar situations at mobile station 10. The operation of the always-on PPP layer 115 on the always-on mobile station 10 is described below with reference to Figure 3, and the operation of the always-on PPP layer 135 on the always-on PDSN 16, 25 is described later. with reference to Figures 4 and 5. The operation of the remaining protocol layers shown in Figure 2 is within the knowledge of those skilled in the art, and is described in more detail in the Standards. The physical layer air link between the always-on mobile station and the RN is described in TIA / EIA / IS-2000-2. The MAC system between the always-on station and the RN is described in TIA / EIA / IS-2000-3. The LAC between the always-on mobile station and the RN is described in TIA / EIA / IS-2000-4. Layer 3 signaling messages used to control the physical layer are described in TIA / EIA / IS-2000-5. The Radio Link Protocol (RLP) between the always-on mobile station and the RN is described in TIA / EIA / IS-707. The RP protocol also known as A10 and A11 is described in 3GPP2 A.S0001, 3GPP2 A.S0011-0. 3GPP2 A.S0012-0, 3GPP2 AS0013-0, 3GPP2 A.S0014-0, 3GPP2 A.S0015-0, 3GPP2 A.S0016-0, 3GPP2 A.S0017-0.

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Figure 3 shows a block diagram of an example of an always-on mobile station 310, and Figures 4 and 5 show block diagrams of an example always-on PDSN 425. Also shown in Figures 3-5 are exemplary communications 350, 355, 370, 380, 390, 471, 472 between the always-on mobile station 310 and the always-on PDSN 425, which can be used to keep the PPP session always on. active.

Referring first to Figure 3, the exemplary mobile station (MS 310 includes an always-on MS module, a processor 320, a transceiver 322, an idle timer estimate 330, and the other modules of the mobile station 340. Processor 320 may be a microprocessor, digital processor, or some other type of processing device. Transceiver 322 is operable to transmit and receive RF signals, and may include a single transceiver circuit or separate transmitter and receiver circuits. The always-on MS module 315 may be a software module, a hardware module, or a combination of both, and be operative to configure and track the idle timer estimate 330. The idle timer estimate 330 may be a timing device, such as a backcounting computation counter, that is configured by the always-on 315 MS module, to estimate the value of the idle timer 430 in the always-on PDSN 425 (see figures 4 and 5). The other modules 340 may be software and / or hardware modules, typically included in mobile station 310, such as the display, keyboard, speaker, microphone, etc.

Operationally, when a PPP session 390 is initiated, between mobile station 310 and always-on PDSN 425, PDSN 425 transmits link control protocol (LOP) message to mobile station 310, which includes an estimate 355 of the value of start, which is generated by the PDSN as a function of the initialization value of the idle timer 430 in the PDSN 425. When the mobile station 310 receives the LCP message 350, the start value estimate 355 is used by the idle timer estimate module MS, and an LCP response message 360 ​​is transmitted from the mobile station 310 to the PDSN 425. Always active.

The value of the idle timer estimate 30 affects the operation of the always-on MS module 315, particularly in blackout situations. That is, the always-on connection to the PDSN 425 is maintained as long as the idle timer estimate 330 has not expired. During periods of inactivity, the always-on MS module 315 causes the inactivity timer to decrease its count from the estimate 355 of the start value. Each time the PPP frame is sent or received by mobile station 310, the idle timer estimate 330 is reset to the value of the start value estimate 355. To maintain an always-on connection during idle periods, the always-on 315 MS can send and receive LCP messages or other PPP session communications 350, 360, 370, 380, 390 to / from the always-on PDSN 425. Upon completion of the idle timer estimate 330, the mobile station 310 may initiate a new PPP session, or it may enter an idle state. If a new PPP session 390 is initiated by mobile station 310, then mobile station 310 may receive a new estimate 355 of the start value from PDSN 425, or it may reset the idle timer estimate 330, using estimate 355 of the Start value from the previous PPP session. The operation of mobile station 310 is further described below with reference to Figures 6-8.

Referring now to FIG. 4, the exemplary always-on PDSN 425 includes an always-on PDSN module 415, a processor 420, a transceiver 422, an inactivity timer 430, and other PDSN modules 440. Processor 420 can be a microprocessor, digital signal processor, or some other type of processing device. The transceiver 422 can be for example a network card that is configured to send and receive data over a radio link through a radio network (RN) 14, 22. The always active 415 PDSN module can be a software module , a hardware module, or a combination of both, and being operable to reset and track the idle timer 430. The idle timer 430 can be a timing device, such as a down-count counter, and can be used by the always-on PdSn 425 to monitor the amount of time since a PPP frame was sent or received from. mobile station 310 always active.

Optionally, upon entering the open state of the IP Control Protocol (PCP) in a PPP session, the PDSN 425 initializes the idle timer 430, and sends an LCP message 350 to the mobile station 310 that includes an estimate 355 generated as a function. of the start value of the inactivity timer 430. The estimate 355 of the start value is used by the mobile station 310 to estimate the value of the inactivity timer 430, as described above. Next, when the processor 420 in the always-on PDSN 425 detects PPP activity with an always-on MS 310, the always-on PDSN module 415 receives notification of the activity, and resets the idle timer 430 to its starting value. PPP activity that may cause the always-on PDSN 415 module to reset the inactivity timer 430 may, for example, include sending or receiving an LCP 350, 370 message, sending or receiving an LCP 360 reply message, receiving an initiating PPP session 390, or other PPP session communications with mobile station 310.

Figure 5 shows a more detailed block diagram of the always-on PDSN 425 example, showing an echo response time-out timer 460, and an echo request re-entry counter 470, in addition to the components shown in Figure 5. figure 4. The echo reply timeout timer 460 may be used by the PDSN 425, to track the amount of time since an LCP 350 request message or an echo request 471 message has been sent by the PDSN 425. no response from mobile station 310. The echo request reentry counter may record the number of times the PDSN 425

ES 2 261 970 T3 always-on forwards an LCP message 350 or echo request message 471 to mobile station 310 without receiving an LCP, response message 360, or echo response message 472 in response. It will be understood that the LCP 360 message may be a rejection, if for example the mobile station does not support LCP messages 350, as may be the case if the LCP 350 message were a vendor-specific LCP message, as specified in the RFC. 2153.

At the expiration of the idle timer 430, the PDSN 425 may send an echo request message to the mobile station 310 in an attempt to maintain the PPP session to elicit an echo reply message from the mobile station 310. Echo request is sent on PDSN 425, echo response timeout timer 470 is initialized. If the echo reply message is received from mobile station 310, then the always-on PDSN 425 may reset the idle timers 430, and the PPP session will be maintained. Otherwise, if the echo response timeout timer 460 expires, and the echo request reentry counter 470 has not reached a preselected cutoff value (for example, zero), then the always-on PDSN 425 can send another LCP echo request message to mobile station 310, decrease echo request reentry counter 470, and reset echo response time-out timer 460. This process may be repeated until the echo reply message or other PPP activity is received from mobile station 310 or until the value of the echo request reentry counter can reach the cutoff value, at which point the PDSN 425 always-on can close the PPP session. Operation of the always-on PDSN 425 is further described below with reference to FIG. 9.

In order to account for the sending and forwarding of the PDSN 425 of an echo request message at the end of the idle timer 430, the estimate 355 of the start value transmitted to the mobile station 310 can be calculated as following:

SVE = IT + ERT x (ERR + 1), where SVE is the 355 estimate of the start value, IT is the start value of the idle timer 430. ERT is the start value of the echo response timeout timer 430, and ERR is the start value of the echo request reentry counter.

It will be understood, however, that other techniques could be used to calculate the starting value estimate 355 to provide an accurate estimate.

Figures 6-8 are flowcharts illustrating exemplary operation of an always-on mobile station. Referring first to Figure 6, the method begins at step 500, which may take place, for example, when an always-on mobile station is powered. In step 505, the mobile station initiates a PPP session. For example, the mobile station may initiate a call using a packet data service option, such as service option 33. Additional details of the PPP session initiation procedure are available in TIA / EIA / IS-2000-1, TIA / EIA / IS-2000-2, TIA / EIA / IS-2000-3, TIA / EIA / IS -20004, TIA / EIA / IS-2000-5, and TIA / EIA / IS-707, which are incorporated herein by reference. The PDSN may open a PPP session for the mobile station, causing the mobile station to enter the open state of the IP control protocol in step 510.

In step 515, the mobile station determines whether it has received a message with a data field, such as an LCP message from the PDSN, that includes an estimate of the start value, as described above. It will be understood that, however, the mobile station may receive the estimate of the start value in other ways, such as via an A-interface message on a new version of A-interface sent from the PDSN to the RN, and then to the MS by means of a message defined in a new version of IS-707. In any case, if the expected message is not received by the mobile station within a predetermined time interval, then the method proceeds to Figure 8. Otherwise, if the message with the expected data field is received within a predetermined time interval, then the method advances to Figure 7.

Referring now to FIG. 7, the method continues from FIG. 6. In step 600, the estimation of the idle timer at the mobile station proceeds to be reset to zero. For example, if the mobile station has received an estimate of the start value of 60 seconds in Figure 6, then the estimate of the idle timer can be set to 60, and decreased once per second such that it ends at zero. In step 605, the mobile station monitors PPP activity. If PPP activity is detected, then the method returns to step 600. Otherwise, if no PPP activity is detected, then the method continues to step 610. PPP activity can for example be detected by sending or receiving of a PPP packet to / from the PDSN and / or sending or receiving an acknowledgment.

In decision step 610, the mobile station determines whether a condition exists to make the mobile device unreachable by the PDSN. The unreachable condition, for example, could be the result of losing the pager channel, making a voice telephone call, using a service option such as an EVRC, when the radio interface does not support common services, or by other reasons. If there is no condition that makes the mobile station unreachable, then the method returns to step 605. Otherwise, if there is a condition that makes the mobile station unreachable, then the method will continue to step 615.

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In decision step 615, the mobile station determines whether it has become reachable by the PDSN. This can occur, for example, if the mobile station has reacquired the Pager Channel after a loss of the pager channel, or terminated a voice phone using a service option such as the EVRC system, or for other reasons. . If the mobile station is not yet reachable, then the method remains at decision step 615. Otherwise, if the mobile station becomes reachable, then the method continues at decision step 620.

In decision step 620, the mobile station determines whether the inactivity timer estimation has ended. If the inactivity timer estimation at the mobile station has not finished, then the process continues at step 605. If the inactivity timer estimation has finished, however, then the method continues at step 625. At step 625, the mobile station sends an LCP request message to the PDSN and awaits the response. Once the mobile station receives an LCP response from the PDSN in step 630, the process continues in step 600.

Turning now to Figure 8, the method continues to Figure 6. In decision step 700, the mobile station determines whether a condition exists that makes the mobile station unreachable by the PDSN, as described above with reference to step 610 in FIG. 7. If there is no condition that makes the mobile station unreachable, then the method remains at step 700, and the mobile station continues normal operation. Otherwise, if there is a condition that makes the mobile station unreachable, then the process continues at step 705. At decision step 705, the mobile station determines whether it is reachable by the PDSN again. For example, the mobile station may become reachable if it requires the Paging Channel, terminates a voice telephone communication using a service option such as EVRC, or for other reasons. If the result of decision step 705 is that the mobile station is not yet reachable, then the process remains at decision step 705. If the result of decision step 705 is that the mobile station has become reachable, however, then the mobile station initiates a PPP session in step 710, and the method is repeated.

FIG. 9 is a flow chart showing an exemplary operation of the always-on PDNS system. The method begins in step 800 when the PDSN initiates a PPP session with a mobile station. At step 805, the PDSSN enters the IPCP Open state, and the process continues at step 810. In step 810, the PDSN sends an LCP message, such as an echo request message, including a data field of non-zero length, including the estimate of the start value, as discussed above. Next, in step 815, the PDSN begins (or resets) the inactivity timer. For example, if the value of 60 seconds is used for the idle timer start value, then the PDSN can set the idle timer to 60, and reduce the timer once per second, so that it ends at zero.

Once the idle timer has been set, the method monitors PPP activity at step 820. If PPP activity has been detected, then the method returns to step 815. Otherwise, if no PPP activity is detected, then the method continues at step 825. PPP activity can, for example, be detected by sending or receiving a PPP packet to / from the mobile station. In decision step 825, the PDSN determines whether the inactivity timer has expired. If the inactivity timer has not expired, then the method returns to step 820. Otherwise, the method continues to step 830.

In step 830, the PDSN sends an LCP message, such as an echo request message, to the mobile station. Next, in step 835, the PDSN starts an echo reply timeout timer, and reduces an echo request reentry counter by one. In step 840, the PDSN monitors a PCP echo reply message, an LCP echo request message, or any other PPP data from the mobile station. If a PPP message is received in step 840, then the echo reply timeout timer is stopped in step 845, and the method returns to step 815. Otherwise, if the PPP message is not received in the step 840, then the method continues to step 850.

In decision step 850, the PDSN determines whether the echo response timeout timer has expired. If not, then the method returns to step 840. If the echo response timeout timer has, however, expired, then the method continues to step 855. In decision step 855, the PDSN determines whether the echo request reentry counter is greater than zero. If the counter is greater than zero, then the method returns to step 830. Otherwise, if the echo request reentry counter is not greater than zero, then the PPP session is released in step 860, and the method terminates.

This written description uses examples to set forth the invention, including the best mode, and also to enable a person skilled in the art to make and use the invention. The patentable scope of the invention may include other examples that are made for those skilled in the art. For example, in one embodiment an always-on APN may include an always-on radio network (RN) that cooperates with the always-on PDSN, and the always-on mobile station, to treat voice communications as a PPP activity. The always-on PDSN can determine from the always-on RN that the always-on mobile station is in progress on a voice call, and thus that the mobile station is unreachable for the purpose of PPP communication. In this case, the always-on PDSN may treat the always-on mobile station as if it were active for PPP purposes.

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Industrial applicability

The invention relates to a system and method for always-on (IP) radio-electric Internet protocol communication with a mobile station, such as a two-way pager device, a cell phone, a laptop, or another. type of radio device.