JP5596584B2 - Wireless communication terminal, uplink information prediction method and uplink information prediction program using the same - Google Patents

Description

  The present invention relates to a wireless communication terminal that can use a plurality of wireless communication systems, an uplink information prediction method using the same, and an uplink information prediction program.

  In recent years, multi-mode terminals that can use a plurality of wireless communication systems have been developed. Such a multi-mode terminal measures or estimates the communication quality of a wireless system that can be used in advance, and selects an advantageous wireless system. That is, the wireless communication method is appropriately selected by grasping the performance in the uplink direction (multimode sensor terminal → wireless base station direction) in each method in advance.

  For example, the wireless communication device described in Patent Document 1 evaluates the quality of a communication link that changes from moment to moment, and selects an optimum communication method and transmission mode to achieve both improvement in transmission capacity and communication reliability. . Then, an estimated value of the received CNR (carrier power to noise power ratio) is used as communication quality information. The reception CNR is estimated by calculating the ratio between the power value of the average signal point vector of the signal point vectors obtained as a reception result and the variance value of each vector based on the average signal point vector. Alternatively, a maximum likelihood sequence estimation or maximum likelihood decoding is performed, and an equivalent received CNR value is estimated from a metric value at that time.

JP 2009-147906 A

  However, generally, the communication quality that can be estimated from the received CNR is only the downlink communication quality, and does not match the uplink communication quality transmitted from the terminal side. In addition, if a multimode sensor terminal is actually connected to a base station for a plurality of wireless systems in order to grasp the uplink communication quality on the terminal side, the load on the base station and the load on the multimode sensor terminal are enormous. Can be. In particular, when a large number of multi-mode sensor terminals are arranged or when the number of available wireless systems increases, the influence is significant.

  The present invention has been made in view of such circumstances, and enables wireless communication that enables estimation of uplink communication quality without connection to a base station, and can reduce the load on the base station and terminals required for quality estimation. It is an object to provide a terminal, an uplink information prediction method using the terminal, and an uplink information prediction program.

  (1) In order to achieve the above object, a wireless communication terminal of the present invention is a wireless communication terminal that can use a plurality of wireless communication schemes, including past peripheral environment information and past information including information in other terminals. A history database that stores uplink information for surrounding environment information, and an uplink information prediction unit that refers to the stored surrounding environment information and predicts current uplink information in the own device for each wireless communication method. It is characterized by that.

  Thus, since the uplink information is predicted with reference to the accumulated surrounding environment information, the uplink information can be predicted without establishing a connection with the radio access infrastructure. As a result, it is possible to prevent an increase in the load on the wireless access infrastructure and the wireless communication terminal required for uplink quality estimation.

  (2) In the wireless communication terminal of the present invention, the uplink information prediction unit compares the accumulated surrounding environment information with the current surrounding environment information in the own device, and each wireless communication based on the comparison result It is characterized by predicting uplink information for a scheme. As a result, it is possible to predict uplink information using information similar to the surrounding environment information, and to improve the accuracy of prediction.

  (3) Further, in the wireless communication terminal of the present invention, the history database stores at least downlink information as the surrounding environment information, and the uplink information prediction unit includes the stored downlink information and the own device. It is characterized by comparing with current downlink information. Thereby, uplink information can be predicted based on downlink information without establishing a connection with the radio access infrastructure.

  (4) In addition, the wireless communication terminal of the present invention is further characterized by further comprising an information collection unit that collects ambient environment information stored in the history database from another terminal using a multi-hop network. Thereby, it is possible to predict uplink information using a multi-hop network without connecting to a radio access infrastructure.

  (5) Further, the radio communication terminal of the present invention is characterized in that the uplink information prediction unit compares time information or position information as the surrounding environment information. For example, when the time when the surrounding environment information is acquired is near, the surrounding environment information can be predicted as information in a situation similar to the current own device. It can also be determined whether or not the situation is close whether the day of the week is the same or whether the time zone is the same. Further, it is possible to compare the position information of the past surrounding environment information and determine whether or not the current position is close to the own device.

  (6) In the wireless communication terminal of the present invention, the information collection unit determines whether the accumulated surrounding environment information satisfies a predetermined standard in quality or quantity, and does not satisfy the predetermined standard When it is determined that the ambient environment information is newly collected, the surrounding environment information is newly collected. Thereby, the uplink information of each wireless communication method can be accurately predicted based on sufficient information.

  (7) In addition, the wireless communication terminal of the present invention is further characterized by further comprising a wireless communication system selection unit that selects a wireless communication system based on the predicted uplink information. As a result, it is possible to select a radio communication scheme that is optimal for the own device based on the predicted uplink information.

  (8) Further, the uplink information prediction method of the present invention is an uplink information prediction method using a radio communication terminal that can use a plurality of radio communication schemes, and includes past peripheral environment information including information on other terminals. And storing the uplink information for the past surrounding environment information, and referring to the stored surrounding environment information and predicting the current uplink information in the own device for each wireless communication system. It is characterized by.

  As a result, the uplink communication quality can be estimated without establishing a connection between the wireless communication terminal and the wireless access infrastructure. As a result, it is possible to prevent an increase in load on the wireless access infrastructure and the wireless communication terminal required for quality estimation.

  (9) Further, the uplink information prediction program of the present invention is an uplink information prediction program to be executed by a wireless communication terminal that can use a plurality of wireless communication schemes, and includes past peripheral environment information including information on other terminals. And a process of storing uplink information for the past surrounding environment information, and a process of referring to the stored surrounding environment information and predicting current uplink information in its own apparatus for each wireless communication method. It is characterized by.

  As a result, the uplink communication quality can be estimated without establishing a connection between the wireless communication terminal and the wireless access infrastructure. As a result, it is possible to prevent an increase in load on the wireless access infrastructure and the wireless communication terminal required for quality estimation.

  According to the present invention, uplink communication quality can be estimated without connecting to a radio access infrastructure, and the load on the radio access infrastructure and terminals can be reduced in quality estimation.

It is a figure which shows an example of the radio | wireless communications system which comprises a multimode sensor network. 1 is a conceptual diagram of a wireless communication system. It is a functional block diagram of a radio | wireless communication terminal. It is a flowchart which shows operation | movement of a radio | wireless communication terminal. It is a table which shows the example of the data currently recorded on the history database. It is a flowchart which shows an example of the process of a situation similarity confirmation. It is a table which shows the example of surrounding environment information.

  Next, embodiments of the present invention will be described with reference to the drawings.

(Wireless communication system)
FIG. 1 is a diagram illustrating an example of a wireless communication system 10 that forms a multimode sensor network, and FIG. 2 is a conceptual diagram of the wireless communication system 10. The wireless communication system 10 includes a wireless communication terminal 100, other multimode sensor terminals 200, a wireless access infrastructure 300, and a sensing data management server group 400. The wireless communication terminal 100 is a multimode sensor terminal.

  The wireless communication terminal 100 can use a plurality of types of wireless access infrastructures 300 based on CDMA2000 1xEV-DO, W-CDMA, WiMAX, LTE, etc. deployed in the field. Can communicate with. Data sensed by the wireless communication terminal 100 is transmitted to the sensing data management server group 400 using any line of another multimode sensor network. Sensing data includes surrounding environment information. In addition, the wireless communication terminal 100 is battery-driven, and can secure installation flexibility. The sensing data management server group 400 collects and manages ambient environment information from the multi-mode sensor terminal 200.

(Wireless communication terminal)
FIG. 3 is a functional block diagram of the wireless communication terminal 100. The wireless communication terminal 100 is capable of multi-hop communication and can use a plurality of wireless communication methods. The wireless communication system is a communication system used with a radio access infrastructure such as CDMA2000 1xEV-DO, W-CDMA, WiMAX, LTE, or other terminals. The wireless communication terminal 100 includes a history database 110, an information collection unit 120, an own device information monitoring unit 140, an uplink information prediction unit 150, a wireless communication method selection unit 160, and a wireless communication unit 170.

  The history database 110 stores surrounding environment information for each of a plurality of wireless communication methods. Specifically, the history of the surrounding environment information obtained by communication with other multi-mode sensor terminals capable of multi-hop communication is accumulated. The surrounding environment information is downlink information, time information, position information, moving speed, etc. for each wireless communication method. The downlink information is information indicating the ease of receiving downlink communication, such as downlink communication quality information and attenuation. It should be noted that information that has passed for a certain period from the time of acquisition based on time information may be set to be deleted.

  The information collecting unit 120 collects ambient environment information to be accumulated in the history database 110 from the outside. Although it is preferable to collect ambient environment information from other multi-mode sensor terminals 200 via a multi-hop network, information may be collected from the sensing data management server group 400. In this way, necessary information can be collected without connecting to the radio access infrastructure 300 such as a base station.

  The information collecting unit 120 checks the history database 110 and determines whether the accumulated surrounding environment information satisfies a predetermined standard in quality or quantity. For example, whether or not the acquisition date and time of the accumulated information is before a predetermined period (information quality), whether or not the number of information acquired in each situation is a predetermined number or more, and data for the number of wireless communication methods It is determined whether or not there is (amount of information). The predetermined determination criterion is preferably set as a period or a number in which the surrounding environment information in a similar situation can be referred to.

  When it is determined that the accumulated surrounding environment information does not satisfy a predetermined standard in quality or quantity, the information collecting unit 120 newly collects the surrounding environment information using the multi-hop network. In such a case, the wireless communication terminal 100 collects ambient environment information from the multi-mode sensor terminal 200 that exists in the vicinity thereof. The ambient environment information may be collected from the sensing data management server group 400.

  The own device information monitoring unit 140 monitors the surrounding environment information of the own device. The surrounding environment information of the own device includes hardware information such as battery information and MIMO antenna configuration information, information on the current signal attenuation in the downstream direction, current time information, and own device position information.

  The uplink information prediction unit 150 refers to the accumulated surrounding environment information and predicts uplink information for each of a plurality of wireless communication schemes. Uplink information is information specific to uplink communication such as an uplink transmission rate and transmission power. The uplink information prediction unit 150 compares the surrounding environment information stored in the history database 110 with the surrounding environment information of the own device, and predicts uplink information for each of a plurality of wireless communication schemes based on the comparison result. In that case, the surrounding environment information close to the surrounding environment information of the own device is used. In particular, comparison of downlink information is important.

  It is also effective to compare the times when downlink information is detected. For example, a similar situation can be predicted when the time when the surrounding environment information is acquired is close. It can also be determined whether or not the situation is close whether the day of the week is the same or whether the time zone is the same. It is preferable to compare each item of the surrounding environment information by weighting. As a result, it is possible to compare the similarity of situations by weighting important items having a large influence on the uplink information, and to improve the prediction accuracy. At the time of comparison, for example, similarity can be determined based on whether the reference value is within a predetermined range.

  In this way, the uplink information prediction unit 150 compares the surrounding environment information of a plurality of radio communication schemes and predicts the uplink information of each radio communication scheme. In that case, it can be predicted that the uplink information when similar surrounding environment information is obtained is close to the uplink information when the own device is connected by the wireless communication method at that time. Uplink information indicates at least one of an uplink transmission rate and transmission power. For uplink information, information obtained at other terminals may be used as it is, or information obtained at other terminals may be corrected according to the situation of the own device. In the prediction, a value obtained by performing statistical processing such as averaging processing can be regarded as an expected value of the transmission rate and employed. Statistical processing includes the use of arithmetic mean, median, and the like.

  Thus, since the uplink information is predicted with reference to the accumulated surrounding environment information, the uplink information can be predicted without establishing a connection with the radio access infrastructure. As a result, it is possible to prevent an increase in load on the radio access infrastructure 300 and the radio communication terminal 100 in quality estimation.

  The wireless communication method selection unit 160 selects a wireless communication method based on the predicted uplink information. For example, referring to the transmission rate and transmission power for each wireless communication method, a wireless communication method with a large transmission rate or a wireless communication method with a small transmission power can be selected according to the remaining power of the own device. When the device's remaining power is small, the wireless communication method can be selected with emphasis on low transmission power, and when the device's remaining power is sufficiently large, the wireless communication method can be selected with an emphasis on the transmission rate. You can choose. As described above, the wireless communication method selection unit 160 appropriately selects an appropriate wireless method.

  The wireless communication unit 170 enables wireless communication connection by a plurality of wireless communication systems such as CDMA2000 1xEV-DO, W-CDMA, WiMAX, and LTE. The wireless communication unit 170 enables communication with another multimode terminal 200 or the wireless access infrastructure 300. As described above, the wireless communication terminal 100 uses the past history of peripheral multi-mode sensor terminals and the like, and uses the transmission rate obtained in a similar environment as information on the uplink transmission quality obtained from now on. To do.

(Operation of wireless communication terminal)
FIG. 4 is a flowchart showing the operation of the wireless communication terminal. When a transmission request for sensing data is generated (step S1), the wireless communication terminal 100 starts estimating uplink information for all communication methods (step S2).

  The wireless communication terminal 100 first searches the history database 110 to estimate uplink information (step S3). In the history database 110, the uplink transmission rate obtained in the past for each wireless communication method is recorded together with the surrounding environment information at that time. The history database 110 is formed in advance by exchanging information with the surrounding multi-mode sensor terminal 200 or the sensing data management server group 400. In addition, the past surrounding environment information of the own machine may be recorded.

  First, the wireless communication terminal 100 checks whether or not the quality and amount of data recorded in the history database 110 satisfy a predetermined standard (step S4). When it is determined that the quality or amount of data recorded in the history database 110 does not satisfy a predetermined standard, a request packet is broadcast again to the surrounding multi-mode sensor terminal 200 to collect information (step S5). . Then, the process proceeds to step S6.

  On the other hand, if it is determined that the quality or amount of data recorded in the history database 110 satisfies a predetermined standard, the process directly proceeds to step S6. Based on the data recorded in the history database 110, uplink information (such as a transmission rate obtained in the uplink direction) is predicted (step S7). In this way, the wireless communication terminal 100 searches the history database 110 to calculate and record uplink information obtained in an environment most similar to the current situation. This is repeated for all communication methods (step S8), compared between the methods, and a wireless communication method to be finally used is selected (step S9). Then, sensing data is transmitted (step S10), and the process ends. The above operation is performed by causing the wireless communication terminal to execute a program.

(Example)
Next, specific operations of the wireless communication terminal 100 will be described with reference to examples.

  There is an attenuation amount of a signal transmitted from the radio base station as a parameter for confirming the similarity between the current situation and the situation described in the history database. Since the similarity of the attenuation from the base station means the similarity of the environment between the base station and the mobile device, the closest result of the attenuation can be used as the evaluation value.

  FIG. 5 is a table showing an example of data recorded in the history database. In the example shown in FIG. 5, the attenuation amount from the base station is used as a search key. Accordingly, when the attenuation at the wireless communication terminal 100 is measured as 150 [dB], it is determined that the case of the attenuation of 145 [dB] in the table is most similar. When accessing the system, it is assumed that a transmission rate of 2,600 [kbps], which is a past history, is obtained. When a plurality of data having the same attenuation amount exist, a value obtained by averaging processing is regarded as an expected value of the transmission rate and adopted. The statistical processing here may be addition averaging, median adoption, or the like, but optimal statistical processing may be employed as appropriate. The same applies to the calculation of the attenuation amount as the search key, and it is possible to use values subjected to various statistical processes such as an average value, maximum value, minimum value, and median value in the time direction.

  There is time information registered in the history database as a parameter for confirming the similarity between the current situation and the situation described in the history database. Since the uplink transmission rate greatly depends on the number of simultaneously connected users and the like, if the data is in a closer time zone, the number of simultaneously connected users is likely to be similar, and the possibility of a closer situation is high. In addition, since the traffic volume generally depends on the day of the week and time of day, it is possible to recognize data on the same day of the week and time as similar situations.

  FIG. 6 is a flowchart illustrating an example of the situation similarity confirmation process. As shown in FIG. 6, first, search by time and similarity confirmation are performed (step T1). Next, search based on the attenuation amount and confirmation of similarity are performed (step T2). Based on the similarity obtained by these processes, data having high similarity is determined, and the transmission rate to be obtained is determined.

  FIG. 7 is a table showing an example of the surrounding environment information. An example when the above similarity confirmation and transmission rate determination processing is performed will be described using the example shown in FIG. First, data subsequent to the current time by a threshold T is referred to as the latest data. If the time is 2010-12-28 20:25:10 and T is 1 [h], the data of “2010-12-28 19:45:10” and “2010-12-28 19:12 : 30 ”is referred to as the latest data.

  Next, assuming that the attenuation amount is 138 [dB], it is assumed that the attenuation amount in the range within the threshold L [dB] is similar to this value. In this case, if L is 5 [dB], both of the two reference data are candidates for similar data.

  Then, for example, a transmission rate that can be expected when the method is used is predicted from the transmission rate. An addition average of the transmission rates obtained here may be adopted, and a maximum value, a minimum value, or a median value may be adopted.

  Further, when data on the same day of the week is also referred to, data within the threshold T is referred to among the data on the same day of the week in the above transmission rate prediction process. In addition to the items described in the embodiment, the availability of MIMO is also important for the situation similarity determination, and these items are registered in the history database 110 as shown in FIG. It is also possible to regard this as a similar environment.

  In this way, the present invention makes it possible to select an optimal wireless communication system while reducing the load on the wireless access infrastructure 300 and the power consumption. As a result, a wireless communication terminal capable of selecting an optimum method from various wireless methods can be realized.

10 wireless communication system 100 wireless communication terminal 110 history database 120 information collecting unit 140 own device information monitoring unit 150 uplink information prediction unit 160 wireless communication method selection unit 170 wireless communication unit 200 multimode sensor terminal 300 wireless access infrastructure 400 sensing data management Server group

Claims (7)

A wireless communication terminal that can use a plurality of wireless communication methods,
A history database that accumulates past peripheral environment information and uplink information for the past peripheral environment information, including information on other terminals;
An uplink information prediction unit that refers to the accumulated surrounding environment information and predicts current uplink information in the own device for each wireless communication method ,
The history database accumulates at least downlink information as the surrounding environment information,
The uplink information prediction unit compares the accumulated downlink information with current downlink information in the own device, and predicts uplink information for each wireless communication scheme based on a comparison result. Wireless communication terminal. The wireless communication terminal according to claim 1 , further comprising an information collection unit that collects surrounding environment information accumulated in the history database from another terminal using a multi-hop network. The wireless communication terminal according to claim 1 , wherein the uplink information prediction unit compares time information or position information as the surrounding environment information. The information collecting unit determines whether or not the accumulated surrounding environment information satisfies a predetermined criterion in quality or quantity, and newly determines the surrounding environment information when it is determined that the predetermined criterion is not satisfied The wireless communication terminal according to claim 2, wherein: The radio communication terminal according to any one of claims 1 to 4 , further comprising a radio communication scheme selection unit that selects a radio communication scheme based on the predicted uplink information. An uplink information prediction method using a wireless communication terminal that can use a plurality of wireless communication methods,
Accumulating past peripheral environment information and uplink information for the past peripheral environment information, including information on other terminals;
The reference to the stored environmental information, see contains a step of predicting a current uplink information, the in own apparatus for each wireless communication system,
In the step of accumulating the information, at least downlink information is accumulated as the surrounding environment information,
In the step of predicting the uplink information, the accumulated downlink information is compared with the current downlink information in the own device, and the uplink information for each wireless communication scheme is predicted based on the comparison result. And an uplink information prediction method. An uplink information prediction program to be executed by a wireless communication terminal that can use a plurality of wireless communication methods,
Processing for storing past peripheral environment information and uplink information for the past peripheral environment information, including information on other terminals;
A process of referring to the stored surrounding environment information and predicting current uplink information in the own device for each wireless communication method,
In the process of storing the information, at least downlink information is stored as the surrounding environment information,
In the process of predicting the uplink information, the accumulated downlink information is compared with the current downlink information in the own apparatus, and the uplink information for each wireless communication scheme is predicted based on the comparison result. And an uplink information prediction program.

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