JP4896667B2 - Wireless communication method and apparatus - Google Patents

Description

  The present invention relates to a wireless communication method and apparatus.

  In a wireless communication system, a modulation class used by a terminal (UT) varies depending on the wireless situation. In the current system, the modulation class that defines the modulation method used between the base station and the terminal in the wireless communication system is not determined by parameters other than the wireless condition, and is generally modulated in the wireless communication system. The class is determined by the reception level (power) of the received signal of the terminal. The determination of the modulation class based on the reception level does not take into account the application throughput, WAN, or communication status of the other party. If the modulation class is determined only by the radio conditions, the opposing system (that is, the partner terminal with which the terminal has a session, the upper line of the base station, the upper network, the relay system, etc.) cannot provide sufficient throughput. There is a risk of using a modulation class that is weak against noise and easy to cut using a high modulation class.

  In other words, for reasons other than the radio conditions between the terminal and the base station, i.e., the base system using a high modulation class, despite the fact that the opposing system is mainly a bottleneck and only low throughput is feasible. It is possible to establish access between the station and the terminal. For example, when the counterpart terminal of the opposing system is connected by wireless communication, there are various conditions such as the weather at the location where the counterpart terminal is located, the distance between the counterpart terminal and the base station, the shielding, the generation of the radio communication method, etc. Depending on the factors, the throughput of the countermeasure system varies greatly. Here, when the throughput of the countermeasure system decreases, only a low throughput can be realized even if the wireless communication status of the terminal itself is good.

Further, the throughput of the conventional wireless communication system is much lower than that of the wired communication system. However, the speed of wireless communication systems has been increasing, and communication lines (eg, 64 kbps ISDN, dial-up connection analog modems) of older wired communication systems have been remarkably slow. In particular, many ISDN communication lines are still in use, and when having a session with a partner terminal connected through the ISDN communication line, if the partner terminal is an ISDN communication line, the ISDN line becomes a bottleneck. The throughput of the countermeasure system is much slower than that of the wireless communication system. In such a case, even if a high-throughput modulation method is used on the wireless communication system side, the throughput is suppressed to be lower than the ISDN communication line speed of the counterpart terminal.
Special table 2006-501765 gazette, Special table 2006-501766 gazette

  As described above, in the current wireless communication system, the modulation class is determined only by the wireless state on the own system side (that is, the own terminal side). As for the modulation class of wireless communication, the higher the rate of the modulation class, the more errors with respect to noise and distortion caused by the wireless communication. As a result, the session of the wireless terminal is easily disconnected. In order to increase the throughput, it is necessary to establish a session with a high modulation class (mod class). However, if the throughput on the upper network side (including the countermeasure system) is low, use a higher modulation class. Sending and receiving data has no effect.

  Accordingly, an object of the present invention is to provide a technique (method and apparatus) for selecting a modulation class based on a throughput other than the radio state of the terminal itself (that is, the throughput of a host network or a countermeasure system).

In order to solve the above-described problems, the wireless communication method according to the first invention is:
A wireless communication method in a system including a terminal, a wireless communication device that wirelessly communicates with the terminal, and a higher-level network connected to the wireless communication device,
A modulation class selection step of selecting a modulation class to be used in the wireless communication based on a throughput of a session established by the terminal via the host network .

The wireless communication method according to the second invention is
In the wireless communication method according to the first invention,
In the modulation class selection step, a modulation class is selected based on the maximum throughput among the throughputs calculated during a predetermined time interval.
It is characterized by that.

A wireless communication method according to a third invention is
In the wireless communication method according to the second invention,
In the modulation class selection step, a modulation class is selected based on the maximum throughput obtained every predetermined time interval.
It is characterized by that.

  As described above, the solution of the present invention has been described as a method. However, the present invention can be realized as a device, a program, and a storage medium storing the program substantially corresponding to these, and the scope of the present invention. It should be understood that these are also included.

For example, a wireless communication device (base station device, PDSN, etc.) according to the fourth aspect of the present invention that realizes the present invention as a wireless communication device
A wireless communication device that wirelessly communicates with a terminal,
The wireless communication device is connected to an upper network,
A modulation class selection unit that selects a modulation class used in the wireless communication based on a throughput of a session established by the terminal via the upper network is provided .
The modulation class selection unit may be configured as a modulation class control unit that controls the wireless communication unit so as to select a modulation class to be used for wireless communication with the certain terminal based on the acquired throughput.

  According to the present invention, it is more stable by appropriately selecting and using an appropriate modulation class according to the throughput (that is, the communication status on the counter system side) other than the radio status between the terminal and the base station. Wireless communication can be performed. By stabilizing wireless communication, for example, session disconnection due to wireless noise can be prevented. Also, it is possible to limit the modulation class to a slower and more stable one according to the communication status on the counter system side, and the change of the modulation class is reduced, and the negotiation between the base station and the terminal is also reduced. That is, processing can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a network configuration diagram showing a network configuration according to an embodiment of the present invention. As shown in the figure, a base station (BS) 100 is connected to a terminal (UT) UT 10 by wireless communication. The base station 100 is connected to a PDSN (packet data switching node) 200 via a local server (local site: router) LS. The terminal UT10, the base station (BS) 100, the local server LS, and the PDSN 200 are referred to as the own system for convenience.

  The PDSN 200 is connected to the core network (upper network) CNET of the countermeasure system 300. The opposing system 300 is connected to the core network CNET, the server TSV, the ISDN network ISNET connected to the server TSV, the counterpart terminal T10 connected to the ISDN network ISNET by wire communication, the opposing system side base station TBS, and wirelessly connected thereto. The other party terminal T20 is configured. The terminal UT10 on the own system side establishes a session with the counterpart terminals T10 and T20 on the opposing system side via various lines, networks, servers and the like interposed therebetween. At this time, when a session is established between the terminal UT10 and the counterpart terminal T10, the wired connection between the counterpart terminal T10 and the ISDN network ISNET can only provide a throughput of 64 kbps per channel. Therefore, the throughput of the wired connection on the counter system side is very small compared to the throughput of the wireless connection on the own system side, which becomes a bottleneck. Similarly, when the communication status of the wireless connection between the base station TBS on the opposing system side and the counterpart terminal T20 is poor, it becomes a bottleneck. The present invention provides a technique for selecting the optimum wireless communication system on the own system side in consideration of such throughput on the opposing system side.

  FIG. 2 is a functional block diagram of base station 100 shown in FIG. As shown in the figure, the base station 100 includes a measurement value receiving unit 110, a modulation class control unit 120, a radio-network interface 130, a PDSN side protocol processing unit 140, and a radio protocol processing unit 150. The PDSN side protocol processing unit 140 performs protocol conversion processing of packets transmitted and received between the local server LS (that is, the PDSN 200) existing in the RP network (not shown) and the own device. Further, the wireless protocol processing unit 150 performs protocol conversion processing of data transmitted and received between the terminal UT10 and the own device. The wireless-network interface 130 controls the PDSN side protocol processing unit 140 and the wireless protocol processing unit 150. The measurement value receiving unit 110 transmits the traffic value measured by the PDSN 200, that is, the throughput (which will be described in detail later with reference to FIG. 3) via the local server LS, the PDSN side protocol processing unit 140, and the wireless-network interface 130. Receive. The received data is stored in a storage unit (memory, not shown). The modulation class control unit selects a modulation class based on the received traffic value (throughput). FIG. 4 is a characteristic diagram showing the relationship between the modulation class, data rate, and noise tolerance. The data rate and noise tolerance for the modulation class are in a trade-off relationship, and a modulation method with a higher data rate has a higher probability that a data error will occur with respect to noise. For example, when the traffic value received from the PDSN corresponds to the data rate of the modulation class 6 (modulation scheme 12QAM) in FIG. 4, the radio status of the own system at that time from a modulation class group consisting of classes equal to or less than the modulation class 6 The modulation class is selected according to. In other words, the “restricted modulation class group (m = 0, 1, 2... 8) excluding the high data rate modulation classes 7 and 8 from the normal modulation class group (n = 0, 1, 2,... 8). 2, ..., 6) ", the modulation class adapted to the radio status of the terminal is selected.

  FIG. 3 is a functional block diagram of the PDSN shown in FIG. As shown in the figure, the PDSN 200 includes an IP side protocol processing unit 210, a traffic measurement unit 220, a measured value transmission unit 230, and a BS side protocol processing unit 240. The IP-side protocol processing unit 210 performs protocol conversion processing for packets transmitted and received between the own device and the core network CNET. In addition, the BS side protocol processing unit 240 performs a protocol conversion process for packets transmitted and received between the own apparatus and the local server LS (ie, the base station 100). Then, the traffic measurement unit 220 measures the traffic value (that is, throughput) for each session from the flow rate of packets transmitted and received by the IP side protocol processing unit 210. The measured value transmission unit 230 transmits the measured traffic value to the base station 100 via the BS side protocol processing unit 240. Thus, in the present invention, after measuring the throughput on the core network side on the PDSN side, the information is transmitted to the base station using the interface between the PDSN and the PCF (corresponding to the PDSN side protocol processing unit in this specification). By transmitting to the side, it becomes possible to select a modulation class that can provide an appropriate throughput. As a result, it is possible to establish communication that is resistant to noise while ensuring a sufficient throughput.

  FIG. 5 is a sequence diagram showing throughput calculation and transmission timing in the present invention. As shown in the figure, the PDSN side measures the uplink and downlink throughput for each session. When the specified time has elapsed, the maximum throughput up to that time is transmitted to the base station side. Thereafter, every time the maximum value of the throughput is updated, the value is transmitted to the base station side. As a result, it is possible to sequentially measure the band used on the upper network (that is, the counter system side) and reflect it on the base station side. That is, the modulation class having the highest connectivity can be used.

  FIG. 6 is a diagram illustrating the relationship between the data rate for each modulation class and the throughput transmitted from the PDSN side. (A) in the figure shows the case where the downlink from the PDSN is 300 kbsp and (b) is the maximum throughput of 200 kbps in the uplink. In this case, sufficient throughput can be obtained by selecting modulation class 3 on the downlink and modulation class 5 on the uplink. By using only a modulation class equal to or lower than this modulation class on the base station side, it is not necessary to use an unnecessarily high modulation class, and it is possible to communicate using a modulation scheme with error resistance.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, functions included in each member, each means, each step, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, steps, etc. can be combined or divided into one. Is possible.

It is a network block diagram which shows the network structure by the embodiment of this invention. It is a functional block diagram of the base station 100 shown in FIG. It is a functional block diagram of PDSN shown in FIG. It is a characteristic view which shows the relationship between a modulation class, a data rate, and noise tolerance. It is a sequence diagram showing throughput calculation and transmission timing in the present invention. It is a figure which shows the relationship between the data rate for every modulation class, and the throughput transmitted from the PDSN side.

Explanation of symbols

100 Base station 110 Measurement value reception unit 120 Modulation class control unit 130 Radio-to-network interface 140 PDSN side protocol processing unit 150 Wireless protocol processing unit UT10 Terminal LS Local server 200 PDSN
210 IP side protocol processing unit 220 Traffic measurement unit 230 Measurement value transmission unit 240 BS side protocol processing unit 300 Counter system CNET Core network ISNET ISDN network T10, T20 Counterpart terminal TBS Counter system side base station TSV server

Claims (4)

A wireless communication method in a system including a terminal, a wireless communication device that wirelessly communicates with the terminal, and a higher-level network connected to the wireless communication device,
A radio communication method , comprising: a modulation class selection step of selecting a modulation class used in the radio communication based on a throughput of a session established by the terminal via the upper network . The wireless communication method according to claim 1,
In the modulation class selection step, a modulation class is selected based on the maximum throughput among the throughputs calculated during a predetermined time interval.
A wireless communication method. The wireless communication method according to claim 2,
In the modulation class selection step, a modulation class is selected based on the maximum throughput obtained every predetermined time interval.
A wireless communication method. A wireless communication device that wirelessly communicates with a terminal,
The wireless communication device is connected to an upper network,
A radio communication apparatus comprising: a modulation class selection unit that selects a modulation class used in the radio communication based on a throughput of a session established by the terminal via the upper network.

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