Mobile device and reconnection processing method

The present invention relates to a mobile device that performs a communication reconnection process and a method for reconnecting a communication performed by the mobile device.

Conventionally, the mobile device performs the reconnection process when the handover fails or the synchronization is lost. Since the reconnection process puts a load on the network side, it is controlled so that it is not executed to the limit of the permissible limit. That is, the mobile device sets a predetermined timer value when it detects a handover failure or out of synchronization, starts the timer, and sends a reconnection request to the connection destination when the timer expires to execute the reconnection process. To do. At this time, since the set timer value is fixed, a certain non-communication period occurs under any circumstances. If the synchronization is lost during the user's call, the silence time continues, so that the user performs the disconnection process and calls again. In addition, the call may continue even during the silent time, and a charge may be incurred. Further, since the cell search is continued during the reconnection process, there is a problem that the battery of the mobile device is consumed and the frequency band is occupied.

In Patent Document 1, in order to prevent resource conflict during reconnection processing, a mobile device or base station collects data that affects reconnection collision or resource conflict, and a reconnection timer is based on the collected data. It is stated that the value of is determined. The data collected includes the amount and distribution of connection requests, the number of resources available, the expected duration of one connection, the expected duration of the current connection, a measure of the priority of the connection request, and the expected duration of the new connection request. There are numbers and so on.<patcit num="1"><text>Special Table 2003-518852 Gazette</text></patcit>

<p> However, Patent Document 1 does not specifically show how to calculate the value of the reconnection timer based on the collected data. Since the data collected in Patent Document 1 is data having different dimensions such as number and time, it is difficult to determine an appropriate value of the reconnection timer based on the data having different dimensions. The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to minimize a non-communication period during a communication reconnection process by determining an appropriate reconnection timer value. The purpose is to provide a mobile device that suppresses the load on the communication network and the own device while improving the convenience of the user.</p>

<p> In order to solve the above problem, the invention according to claim 1 sets a reconnection timer value at the time of communication reconnection processing, activates the timer, and transmits a reconnection request to the connection destination when the timer expires. The timer value change trigger storage means for storing a plurality of timer value change triggers and the individual timer value determination rule for each of the timer value change triggers stored in the timer value change trigger storage means are stored. Two or more timer value change triggers are selected from the individual timer value determination rule storage means and the timer value change triggers stored in the timer value change trigger storage means, and the individual timer value for each of the selected timer value change triggers is selected. Based on the individual timer value determining means that determines based on the determination rule stored in the individual timer value determining rule storage means, and two or more individual timer values determined by the individual timer value determining means. Provided is a mobile device provided with a reconnection timer value calculating means for calculating a connection timer value.</p><p> According to the present invention, the mobile device selects two or more timer value change triggers from a plurality of timer value change triggers, and determines an individual timer value for each of the selected timer value change triggers based on a determination rule. Since the reconnection timer value is calculated based on the determined two or more individual timer values, it is possible to easily calculate an appropriate reconnection timer value using two or more individual timer values having a unified dimension. It will be possible. Therefore, during the communication reconnection process, it is possible to minimize the non-communication period, improve the convenience of the user, and reduce the load on the communication network and the own device.</p><p> According to the second aspect of the present invention, in the mobile device according to the first aspect, the reconnection timer value calculating means obtains an average value of two or more individual timer values determined by the individual timer value determining means. It is characterized in that it is calculated as a reconnection timer value. According to the present invention, an appropriate reconnection timer value can be easily calculated by taking the average value of the individual timer values for two or more timer value change triggers.</p><p> According to the third aspect of the present invention, in the mobile device according to the first or second aspect, the reconnection timer value calculating means weights two or more individual timer values determined by the individual timer value determining means. The average value calculated after the calculation is used as the reconnection timer value. According to the present invention, an appropriate reconnection timer value can be easily calculated by weighting individual timer values for two or more timer value change triggers and taking an average value.</p><p> The invention according to claim 4 is the mobile device according to any one of claims 1 to 3, wherein the timer value change trigger stored in the timer value change trigger storage means is QoS (Quality of Service). Class, bearer to which the machine is connected, amount of data stored in the buffer memory of the machine, data retransmission frequency, throughput, amount of communication error, presence / absence of radio interference, number of peripheral cells, straddling tracking area It is characterized in that at least one of the movement speed of the own machine and the number of cell straddles is included. According to the present invention, the optimum reconnection timer value can be calculated by using the timer value change trigger that affects the determination of whether or not the load of the network or the mobile device and the reconnection request should be made immediately.</p><p> The invention according to claim 5 defines a timer value change trigger storage means for storing a plurality of timer value change triggers and a rule for determining an individual timer value for each of the timer value change triggers stored in the timer value change trigger storage means. A timer value stored in the timer value change trigger storage means, which is a reconnection processing method executed by a mobile device provided with an individual timer value determination rule storage means to be stored when a trigger for reconnection of communication occurs. Two or more timer value change triggers are selected from the change triggers, and the individual timer value for each of the selected timer value change triggers is determined based on the determination rule stored in the individual timer value determination rule storage means. Based on the timer value determination step and the two or more individual timer values determined in the individual timer value determination step, the reconnection timer value for calculating the reconnection timer value used for counting the time until the reconnection request is transmitted is calculated. A calculation step, a timer start step in which the reconnection timer value calculated in the reconnection timer value calculation step is set and the timer is started, and a reconnection request is sent to the connection destination when the timer started in the timer start step expires. Provided is a reconnection processing method including a reconnection request transmission step for transmission.</p>

<p> According to the present invention, the mobile device selects two or more timer value change triggers from a plurality of timer value change triggers, and determines an individual timer value for each of the selected timer value change triggers based on a determination rule. Since the reconnection timer value is calculated based on the determined two or more individual timer values, it is possible to easily calculate an appropriate reconnection timer value using two or more individual timer values having a unified dimension. It becomes. Therefore, during the communication reconnection process, it is possible to minimize the non-communication period, improve the convenience of the user, and reduce the load on the communication network and the own device.</p>

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In each of the figures referred to in the following description, the same parts as those of the other figures are indicated by the same reference numerals. (Constitution) FIG. 1 is an overall configuration diagram of a communication system according to an embodiment of the present invention. As shown in the figure, the communication system is composed of a base station 1 and a mobile device 2. Although only one base station 1 is shown in the figure, there are actually a plurality of base stations 1. Each base station 1 relays the wireless communication of the mobile device 2 existing in the area (hereinafter referred to as "cell") in which the own station 1 covers the communication.

The mobile device 2 is configured to be able to communicate with the base station 1 that covers the cell in which the own device 2 exists (hereinafter referred to as attributable cell). The mobile device 2 includes a CPU (Central Processing Unit) (not shown), an internal clock that measures time, a non-volatile memory that stores software such as programs and data, and a volatile memory that is used as a temporary storage memory such as a buffer memory. It has a wireless communication interface, etc. By operating these hardware and software in cooperation, the functional configuration of the mobile device 2 shown in FIG. 1 is realized. The mobile device 2 includes a wireless communication unit 3, a synchronization loss detection unit 4, a timer switching control unit 5, and a timer management unit 6 as functional configurations.

The out-of-synchronization detection unit 4 detects the out-of-synchronization when it does not receive a response (ACK) to the data transmitted to the base station 1 of the cell to which it belongs. When the out-of-synchronization detection unit 4 detects the out-of-synchronization, the timer switching control unit 5 calculates the reconnection timer value, which is the time until the reconnection request is transmitted, which should be timed by the timer, and determines the predetermined reconnection. Set the reconnection timer value in the timer storage area.

The timer management unit 6 activates the timer to manage the time. That is, the timer management unit 6 measures the time from the time when the timer is started, and determines that the timer has expired when the time is measured to the set timer value. In the present embodiment, the timer value to be set includes the reconnection timer value and the retransmission timer value that clocks the time until retransmission is performed. Hereinafter, a timer that measures the time based on the reconnection timer value is referred to as a "reconnection timer", and a timer that measures the time based on the retransmission timer value is referred to as a "retransmission timer".

The wireless communication unit 3 performs wireless access control and performs communication by cell search, circuit switching, and packet switching. For example, the wireless communication unit 3 transmits a reconnection request to the base station 1 of another cell when the reconnection timer started due to the out-of-synchronization has expired. Further, when the synchronization is lost, the wireless communication unit 3 retransmits to the base station 1 of the cell to which it belongs, up to the upper limit of the number of retransmissions, every time the retransmission timer expires. The trigger for starting the reconnection timer is when a reconnection request is sent to base station 1 in another cell due to out-of-synchronization with base station 1 in the cell to which it belongs, and when a handover is made to base station 1 in another cell. There is a case where a reconnection request is transmitted to the base station 1 of the cell to which the cell belongs due to the failure, but in the present embodiment, only the case where the synchronization is lost as a trigger for starting the reconnection timer will be described.

Next, the functional configuration of the timer switching control unit 5 will be described in more detail. FIG. 2 is a block diagram showing a functional configuration of the timer switching control unit 5. As shown in the figure, the timer switching control unit 5 includes a timer value change trigger storage unit 51, an individual timer value determination rule storage unit 52, an individual timer value determination unit 53, and a reconnection timer value calculation unit 54. I have. The timer value change trigger storage unit 51 stores a plurality of timer value change triggers. The timer value change trigger includes the QoS (Quality of Service) class of the communication of the mobile device 2, the bearer to which the mobile device 2 is connected, the amount of data temporarily stored in the buffer memory of the mobile device 2, and the mobile device 2. Data retransmission frequency from, communication throughput of mobile device 2, amount of communication error, presence / absence of radio interference, number of cells existing around the cell to which mobile device 2 belongs, tracking area with 2 mobile devices 2 (TA) ; Tracking Whether or not it straddles the tracking area, which is located at the boundary of Area) and indicates the state of trying to move to another tracking area, the moving speed of mobile device 2, and the number of overlapping cells in the place where mobile device 2 exists. There is a number of cell straddles and the like indicating. The TA is a position management area composed of a plurality of cells, which is a unit for registering the position of the mobile device 2.

The individual timer value determination rule storage unit 52 stores the individual timer value determination rule for each timer value change trigger stored in the timer value change trigger storage unit 51. FIG. 3 is a diagram showing an example of a rule for determining an individual timer value for each timer value change trigger. As shown in the figure, for example, when the timer value change trigger is "QoS class" and the priority of the QoS class is high, there is a rule to shorten the timer length, that is, to reduce the individual timer value. It is set.

FIG. 4 is a diagram showing an example of a rule for determining an individual timer value for each QoS class when the bearer to which the mobile device 2 is connected is LTE (Long Term Evolution). In LTE, QoS is divided into 9 classes, and individual timer value determination rules can be set for each class. The class with "Name of QCI Characteristic" of "1" has the highest priority, and the higher the number of "Name of QCI Characteristic", the lower the priority. Has a rule to shorten the length of the timer so that the reconnection process can be performed immediately.

Returning to Fig. 3, when the timer value change trigger is "Connected bearer", if the connected bearer is LTE, it is possible to connect in a short time, so shorten the timer length. The rules are set. On the other hand, when the connected bearer is UMTS (Universal Mobile Telecommunications System), it takes time to connect, so a rule to increase the length of the timer is set. In addition, when the timer value change trigger is "Buffer accumulation condition" and the amount of data accumulated in the buffer provided by the mobile device 2 is large, the data is reconnected early and the accumulated data is transmitted. Since it is more efficient, rules are set to shorten the length of the timer.

In addition, when the timer value change trigger is "retransmission condition", if there are many data retransmissions, it is more efficient to reconnect earlier than repeating retransmissions, so a rule to shorten the timer length. Is set. In addition, when the timer value change trigger is "throughput", if the communication throughput of the mobile device 2 is high, it is considered that the processing capacity is high and the processing load is not applied even if reconnection is performed, so the length of the timer. There is a rule to shorten and reconnect early. Also, when the timer value change trigger is "quality gradient", if there are many communication errors in the mobile device 2, it is more efficient to reconnect earlier than to resend the data, so the length of the timer A rule is set to shorten the error.

Further, when the timer value change trigger is "presence or absence of interference from another base station", it is determined that there is interference with the base station 1 of another cell based on the desired wave to interference wave ratio measured by the mobile device 2, for example. In this case, since a communication error is likely to occur, it is more efficient to reconnect the data earlier than to retransmit the data, so a rule for shortening the length of the timer is set. Further, when the timer value change trigger is "the number of peripheral cells", if there are many cells around the cell in which the mobile device 2 exists, interference becomes large and a communication error is likely to occur. Similarly, a rule for shortening the length of the timer is set.

In addition, when the timer value change trigger is "whether or not the TA (Tracking Area) is straddled", if the mobile device 2 is in the state of straddling the TA trying to move to another TA, the position registration, etc. is performed. Since processing with a high load occurs, it is better not to perform other processing such as reconnection processing as much as possible, so a rule for increasing the length of the timer is set. Also, when the timer value change trigger is "moving speed", if the moving speed of mobile device 2 is fast, the cell or tracking area to which mobile device 2 belongs will switch in a short time, so those who reconnect. Is efficient, so rules are set to shorten the length of the timer.

Further, when the timer value change trigger is the "number of cell straddles", if the number of cell straddles is large, there is a high possibility that the cell to which the mobile device 2 belongs will switch, and it is efficient to reconnect. , The rule to shorten the length of the timer is set. If the timer value change trigger is "specify the timer length from the network" and the timer length is specified from a predetermined server in the communication network, the timer length is set as the specified value. Rules are set. The types of timer value change triggers and individual timer value determination rules described above are merely examples. For example, individual timer value determination rules may be provided for each connected bearer.

The individual timer value determination unit 53 selects two or more timer value change triggers from the plurality of timer value change triggers stored in the timer value change trigger storage unit 51, and the individual timer for each of the selected timer value change triggers. The value is determined based on the determination rule stored in the individual timer value determination rule storage unit 52. Here, as a method of selecting two or more timer value change triggers, all of a plurality of timer value change triggers stored in the timer value change trigger storage unit 51 may be selected, or the QoS class is connected. A timer value change trigger that has a large effect on the communication environment such as a bearer may be selected with priority, or a timer value change trigger that is important for shortening the non-communication period and reducing the network load in the communication environment at that time may be selected. You may choose.

The reconnection timer value calculation unit 54 calculates the reconnection timer value based on two or more individual timer values determined by the individual timer value determination unit 53. As a method of calculating the reconnection timer value, for example, the average value of two or more individual timer values determined by the individual timer value determination unit 53 is calculated as the reconnection timer value. Alternatively, each of the two or more individual timer values determined by the individual timer value determination unit 53 is weighted, and the average value of the weighted individual timer values is calculated as the reconnection timer value. As a weighting method, for example, weighting is performed by multiplying an individual timer value for an important timer value change trigger such as a QoS class by a large weighting coefficient.

Further, the method of calculating the reconnection timer value is not limited to the average value of the individual timer values, and for example, the standard deviation, the median value, or the sum of the above two or more individual timer values may be used as the reconnection timer value. When calculating the sum of the individual timer values, the individual timer values may be simply added together, or the weighted individual timer values may be added together. Further, the individual timer values may be weighted on the assumption that they are added together.

(motion) Next, as shown in FIG. 5, the operation when reconnecting to the base station 1B of another cell due to the out-of-synchronization with the base station 1A of the cell to which the mobile device 2 belongs is shown in FIG. This will be described with reference to the flowchart shown in 6. Here, since the upper limit of the number of times that the mobile device 2 retransmits to the base station 1A when the out-of-synchronization is detected is 10 times, and 3 seconds is set in advance as the retransmission timer value. It shall take about 30 seconds or more to resend 10 times. When the wireless communication unit 3 does not receive an ACK for the data transmitted to the base station 1A during the communication of the mobile device 2 (step S1), the out-of-synchronization detection unit 4 detects the out-of-synchronization (step). S2).

When the out-of-synchronization is detected, the individual timer value determination unit 53 selects two or more timer value change triggers from the timer value change triggers stored in the timer value change trigger storage unit 51, and changes the selected timer value. The individual timer value for each trigger is determined based on the determination rule stored in the individual timer value determination rule storage unit 52 (step S3). The reconnection timer value calculation unit 54 calculates the reconnection timer value based on two or more individual timer values determined by the individual timer value determination unit 53 (step S4). Here, it is assumed that 30 seconds is calculated as the reconnection timer value. The timer switching control unit 5 sets the calculated reconnection timer value (step S5), the timer management unit 6 activates the reconnection timer (step S6), and further activates the retransmission timer (step S7).

The timer management unit 6 determines whether or not the reconnection timer has expired (step S8). If it is determined that the reconnection timer has not expired (step S8; NO), the wireless communication unit 3 of the mobile device 2 retransmits to the base station 1A to which it originally belonged after the retransmission timer expires (step S8; NO). Step S9). On the other hand, when it is determined that the reconnection timer has expired (step S8; YES), the wireless communication unit 3 executes the reconnection process by transmitting a reconnection request to the base station 1B of another cell (step S8; YES). S10).

When the retransmitted data or the ACK for the reconnection request is received and the communication can be continued (step S11; YES), the mobile device 2 succeeds in reassignment and transitions to the communication (step S13). On the other hand, if no ACK is received for both the retransmitted data and the reconnection request (step S11; NO), the mobile device 2 determines whether or not the number of retransmissions is equal to or greater than the upper limit. (Step S12). If the upper limit of the number of retransmissions has not been reached (step S12; NO), the timer management unit 6 starts the retransmission timer again (step S7), and repeats the processes after step S8.

When the number of retransmissions is 10 or more, which is the upper limit, after about 30 seconds have passed since the out-of-sync detection was detected without success even if the retransmission process was performed several times during that time (step S12; YES). , It is determined that there is no base station 1 that can be connected in the vicinity, and the wireless communication unit 3 of the mobile device 2 disconnects the communication and enters the standby state (step S14). If the reconnection process fails, the determination in step S12 can be omitted and the communication can be disconnected immediately.

As described above, the mobile device 2 selects two or more timer value change triggers from the plurality of timer value change triggers, and determines the individual timer value for each of the selected timer value change triggers based on the determination rule. To do. Since the dimensions of the two or more determined individual timer values are unified, operations such as taking an average value can be performed immediately, and an appropriate reconnection timer value can be easily calculated. .. Therefore, during the communication reconnection process, the non-communication period is minimized to improve user convenience, and the number of reconnection processes and cell search are suppressed to reduce the load on the communication network and mobile device 2. It is also possible to prevent the battery consumption of the mobile device 2 from being consumed.

In the above-described embodiment, the case where the reconnection request is transmitted to the base station 1 of another cell due to the out-of-synchronization with the base station 1 of the cell to which the mobile device 2 belongs has been described. It is also applicable to the case where a reconnection request is transmitted to the base station 1 of the cell to which the device belongs due to the failure of the handover to the base station 1. Further, in the above-described embodiment, the reconnection process during communication has been described, but it can also be applied to the connection process before the start of communication.

<figref num="1">It is an overall block diagram of the communication system which concerns on embodiment of this invention .</figref><figref num="2">It is a block diagram which shows the functional structure of the timer switching control part of the mobile machine which concerns on this embodiment.</figref><figref num="3">It is a figure which shows an example of the determination rule of the individual timer value for each timer value change trigger which concerns on the same embodiment.</figref><figref num="4">It is a figure which shows an example of the determination rule of the individual timer value for each QoS class when the bearer to which the mobile device which concerns on this embodiment is connected is LTE.</figref><figref num="5">It is a figure which shows the state of performing the reconnection processing to the base station of another cell by the out-of-synchronization with the base station of the cell to which the mobile device which concerns on this embodiment belongs.</figref><figref num="6">It is a flowchart which shows the flow of the reconnection processing which concerns on the embodiment.</figref>

Code description

1,1A, 1B base station 2 mobile 3 Wireless communication unit 4 Out of sync detector 5 Timer switching control unit 6 Timer management unit 51 Timer value change trigger storage 52 Individual timer value determination rule storage 53 Individual timer value determination unit 54 Reconnection timer value calculation unit