JP2003264872A - Base station and wireless communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base station wherein no delay in data packets is caused as the length of data is longer and to provide a wireless communication apparatus. <P>SOLUTION: The base station 404 including: a communication control section 402 for transmitting a downlink control channel to a plurality of wireless communication apparatuses; a control means control section 402 for receiving an uplink control channel from a plurality of wireless communication apparatuses; a communication control section 402 for acquiring a communication channel with the wireless communication apparatuses; and a control information transmission section 404 having a channel selection section for assigning a communication channel to the wireless communication apparatus through the downlink control channel, is provided with a communication quantity measurement section 403 for counting the number of packets processed within a prescribed time to calculate a degree of congestion of the base station 400; and the control information transmission section 404 informs the wireless communication apparatus about a degree of congestion of the base station 400 calculated in the communication quantity measurement section 403 through the downlink control channel in the case of performing wireless packet communication. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device and a base station for carrying out wireless packet communication.

[0002]

2. Description of the Related Art One of general wireless telephone systems,
There is a cellular radio telephone system. In order to realize a cellular radio telephone system, a wide area is subdivided. The subdivided area is called a cell, and a fixed station that covers the cell in a radio wave manner is installed. In addition, an exchange station is installed that connects the fixed stations to manage them in an integrated manner. By setting a plurality of cells in this way, it is possible to cover a wide range. Further, the exchange is connected to an existing telephone line network, internet network or the like, and communication with a telephone or communication with a data server becomes possible. Such a system is also used in PHS and the like. It is also used to deploy fixed stations and exchanges on the floor of an office to build a wireless LAN. A data communication service is provided to the wireless communication device via the fixed station and the exchange. Hereinafter, the wireless communication device will be described as a mobile station, and the fixed station will be described as a base station. Due to the nature of packet communication, there is no physical line blockage. That is, the greatest feature of packet communication is that the line can be shared. But,
Inversely, as the number of users sharing a line increases, the communication speed available to users for each line also decreases.

When a mobile station conducts packet communication using a wireless line, when it is extremely delayed that a data packet transmitted through a line having a low communication speed due to congestion arrives at the base station from the mobile station, Retransmission processing will be activated for those that do not arrive within a certain period of time, which has the same effect as if the data packet was lost due to some wireless line failure. In this case, the longer the overall length of the data to be transmitted / received, the larger the retransmission overhead caused by the data packet loss due to the delay.

[0004]

As described above, in the conventional base station and mobile station (radio communication device), the longer the total length of the data to be transmitted and received, the more the retransmission caused by the data packet loss due to the delay. It has a problem that the overhead becomes large.

In this base station and wireless communication device, it is required that the delay of the data packet does not occur as much as when transmitting long data.

It is an object of the present invention to provide a base station in which a data packet delay does not occur as much as when transmitting long data and a wireless communication device in which a data packet delay does not occur as much as when transmitting long data.

[0007]

In order to solve the above problems, a base station of the present invention includes a transmitter for transmitting downlink control channels to a plurality of radio communication devices and an uplink control channel from a plurality of radio communication devices. In a base station having a receiving unit, a communication unit that captures a communication channel with the wireless communication device, and a control information transmitting unit that has a channel selection unit that allocates the communication channel to the wireless communication device through the downlink control channel, It is equipped with a communication amount measurement unit that counts the number of packets processed in time and calculates the degree of congestion of the base station.The control information transmission unit uses the downlink control channel to perform communication when performing wireless packet communication. The wireless communication device is provided with a configuration for notifying the congestion degree of the base station calculated by the measurement unit.

As a result, it is possible to obtain a base station in which a data packet is not delayed as much as when transmitting long data.

In order to solve the above-mentioned problems, a radio communication device of the present invention comprises a transmitting section for transmitting an uplink control channel to a base station, and a receiving section for receiving a downlink control channel from the base station.
In a wireless communication device having a communication unit that captures a communication channel, a packet communication unit that performs packet communication with a base station, and a data length determination unit that determines the length of data to be transmitted / received, a base that performs communication A base station selecting unit that automatically selects a station is provided, and when performing wireless packet communication, the receiving unit receives the congestion degree of the base station notified from the base station on the downlink control channel, The station selection unit has a configuration for automatically selecting a base station to perform communication based on the degree of congestion of the received base station.

As a result, it is possible to obtain a wireless communication device in which the delay of data packets does not occur as much as when transmitting long data.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A base station according to claim 1 of the present invention is a transmitting unit for transmitting downlink control channels to a plurality of wireless communication devices, and a receiving unit for receiving upstream control channels from a plurality of wireless communication devices. A base station having a communication unit that captures a communication channel with the wireless communication device and a control information transmission unit that has a channel selection unit that allocates the communication channel to the wireless communication device through the downlink control channel, within a fixed time. The communication amount measuring unit that counts the number of processed packets and calculates the congestion degree of the base station, and the control information transmitting unit, when performing wireless packet communication, through the downlink control channel, in the communication amount measuring unit The calculated degree of congestion of the base station is notified to the wireless communication device.

With this configuration, it is possible to count the number of packets processed within a fixed time, determine the congestion degree of wireless packet communication, and notify the wireless communication device of the congestion degree via the control channel. Therefore, when the wireless communication device receives the congestion degree information notified via the control channel, it is possible to automatically select the base station that can obtain the optimum communication speed and to transmit the data packet. This has the effect of preventing a decrease in communication speed caused by a retransmission process due to delay.

According to another aspect of the present invention, there is provided a radio communication device, wherein a transmission section for transmitting an uplink control channel to a base station, a reception section for receiving a downlink control channel from the base station, a communication section for capturing the communication channel, and a base station. In a wireless communication device having a packet communication unit that performs packet communication with a station and a data length determination unit that determines the length of data to be transmitted / received, base station selection for automatically selecting a base station to perform communication When the wireless packet communication is performed, the receiving unit receives the congestion degree of the base station notified from the base station on the downlink control channel, and the base station selecting unit receives the received base station. This is to select a base station whose congestion level is lower than a plurality of preset threshold values.

With this configuration, the wireless communication device can receive the congestion degree of the wireless packet communication notified from the base station via the control channel, and the base station is automatically selected by using the congestion degree. Since it is possible to establish a wireless line by doing so, it is possible to automatically select a base station that can obtain the optimum communication speed, and at the time of transmitting a data packet, a decrease in communication speed caused by a retransmission process due to a delay. Has the effect of being able to prevent In addition, since data packets are mainly transmitted to a wireless line that is not congested, the data packets are distributed to the entire base station system, and it is possible to prevent a decrease in communication speed due to congestion. . Also,
By adding a simple configuration (base station selection unit) to the wireless communication device, it is possible to automatically select the base station that provides the optimum communication speed.

A wireless communication device according to a third aspect is the second aspect.
In the wireless communication device described in [1], the plurality of preset threshold values are determined by the data length to be transmitted / received.

With this configuration, not only the congestion degree of the base station but also the situation of the total length of the data to be transmitted / received can be taken into consideration, so that the base station that can obtain the optimum communication speed is automatically selected. In addition to the above, there is an effect that when transmitting a data packet, it is possible to more effectively prevent a decrease in communication speed caused by a retransmission process due to a delay.

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates using FIG.

(Embodiment 1) FIG. 1 is a block diagram showing a base station according to Embodiment 1 of the present invention, and FIG. 2 is a block showing a mobile station (radio communication device) according to Embodiment 1 of the present invention. It is a figure.

In FIG. 1, reference numeral 400 is a base station, 401 is a base station antenna used for transmitting / receiving radio signals to / from a mobile station 500, which will be described later, and 402 is an uplink for establishing a communication channel on the mobile station 500 side. With respect to the control channel, the base station communication control unit that performs processing of capturing and releasing the communication channel with the mobile station 500 side, 403 is a base station communication control unit, The amount of communication that counts whether the number of packets has been processed, digitizes the count result as a congestion degree according to a threshold level defined in advance in the base station, and outputs the digitized congestion degree to the control information transmitting unit 404 described later. A measurement unit, 404 is a control information transmission unit for transmitting the congestion degree received from the communication amount measurement unit 403 to the mobile station 500 on the downlink control channel, and 405 is for the network 600. A line control unit which exchanges of data between the communication control unit 402 and control information transmitting section 404 performs transmission and reception processing of packet data. Here, the communication control unit 402 is a transmission unit that transmits downlink control channels to a plurality of mobile stations, a reception unit that receives uplink control channels from a plurality of mobile stations, and a communication unit that captures communication channels with mobile stations. And the control information transmitting section 404 has a channel selecting section that allocates a communication channel to the mobile station through the downlink control channel.

In FIG. 2, reference numeral 500 is a mobile station, 501 is a mobile station antenna used for transmitting and receiving radio signals to and from the base station 400, and 502 is a control information receiving section 5 described later.
A base station selection unit that performs a process of selecting a communication destination base station 400 using control information including the congestion degree received from 03, and capturing or releasing a communication channel with the selection destination base station 400. And a control information receiving unit 503 that receives control information including a congestion degree from the downlink control channel, digitizes the control information, and outputs the digitalized control information to the communication control unit 502.
An input / output control unit 504 controls input / output of data,
Reference numeral 5 is a data interface unit for inputting / outputting data to / from the outside, and 506 is a data length determining unit for determining the data length to be transmitted / received using the information received from the control information receiving unit 503 or the data interface unit 505. . Here, the communication control unit 502 includes a transmission unit that transmits the uplink control channel to the base station 400, a reception unit that receives the downlink control channel from the base station 400, a communication unit that captures the communication channel, and the base station 400. The control information receiving unit 503 has a base station selecting unit that automatically selects a base station that performs communication.

With respect to the base station configured as described above,
The operation will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of notifying the congestion degree by the base station.

In FIG. 3, the communication amount measuring unit 403 initializes the count of the number of packets, activates a measurement monitoring timer (S1, S2), and counts the number of packets that have passed through the base station in a certain time ( S3, S4, S5). After a certain period of time has passed, the communication amount measuring unit 403 determines the number of packets counted by the threshold A
(S6). When the number of passing packets is large compared to the threshold value A, the congestion level is set to A, and it is determined that the packet is "very crowded" (S7). If the number of passed packets is smaller than the threshold value A, a value smaller than A is compared with the set threshold value B (S8). If it is larger than the threshold value B, the congestion level B is set, and it is determined that it is "slightly congested" (S9). Also, the threshold B
If it is smaller than that, the congestion level is set to C, and it is determined that it is not crowded (S10). The congestion level calculated in this way is reflected in the control channel information (S1
1) The mobile station 500 is notified via the downlink control channel. In this way, the current congestion degree of the base station 400 is reported on the downlink control channel.

Since each base station has a different degree of congestion depending on the line status on the wired side, it is desirable to set the thresholds A and B according to the base station, respectively. When the communication path is congested due to the relationship between stations and the like, the number of packets that can be actually processed may change. In this case, the thresholds A and B can be set according to the number of packets that can be actually processed. desirable.

Next, a procedure for selecting a base station with which the mobile station 500 communicates by using the notified congestion degree is shown in FIG.
This will be described with reference to FIG. FIG. 4 is a flowchart showing a conventional base station selection operation, and FIG. 5 is a flowchart showing a base station selection operation in the first embodiment of the present invention.

Under the conditions of (Table 1), the base stations α, β,
Both γ can accommodate a new packet communication call.

[0026]

[Table 1]

Here, in order to compare with the base station selection method according to the present embodiment, a conventional method in which the total length of transmitted / received data is not considered as a base station selection condition will be described with reference to FIG.

Since packet communication can be performed in a non-congested situation, it is sufficient if it is not very congested. Therefore, after the user calls, the control information receiving unit 503
Sets a congestion level B as a base station selection threshold (S21), and determines whether or not a sufficient speed can be obtained for packet communication (S22, S23, S2).
4). That is, the target base station is selected from the base station candidates (S22), and the congestion degree of the target base station is received (S22).
23), it is determined whether the congestion degree of the target base station is equal to or more than a threshold value (S24). When it is determined in step S24 that the congestion degree is higher than the set threshold value and sufficient speed cannot be obtained, the control information receiving unit 503 removes the congested base station α from the communication destination candidates ( S25), reselecting the base station β from the communicable base stations (S22),
As the temporary communication destination base station, the determination regarding the communication speed is performed again (S23, S24). From (Table 1), the base station β can determine that the congestion level B is less crowded than the threshold value set in step S21. Therefore, the communication control unit 502 of the mobile station 500 , A communication channel establishment request is transmitted using the uplink control channel (S26), the communication channel establishment process is started with the base station β, and the communication channel can be established (S27). Base station β
Since the accommodated packet communication amount is smaller than that of the base station α, even if new packet communication is accommodated, the communication speed provided to each mobile station is higher than that of the mobile station accommodated in the base station α. It is possible to provide a high communication speed. The mobile station can perform data communication more advantageously by selecting the base station β with which the obtained communication speed is relatively high in order to newly perform communication.

The above is the conventional base station selection method.

However, when transmitting / receiving data of a long data length, it is more advantageous to carry out data communication by selecting a base station with less congestion. Therefore, a method of selecting a base station in consideration of the length of data to be transmitted and received will be described with reference to FIG.

In FIG. 5, the data length determination unit 506 is
After the user calls, the length of data to be transmitted / received (data length) is determined (S31). There are various methods for determining the data length, such as a method for directly determining the data length and a method for indirectly determining the data length. Here are some examples:

The first method is a method of describing a series of data lengths in the head data packet, and the data lengths to be transmitted / received can be grasped in advance in the upstream and downstream control channels. The second method is to judge the length of data to be sent / received by clinging to an application. For example, when sending / receiving a short message, the data length is short, when using an internet browser, the data length is long, and when using a videophone. The data length is long when the data is downloaded, and the data length is long when the image / music data is downloaded. Third
The above method is a method of determining the length of the data to be transmitted / received by attaching it to the interface. The data length is short when data is transmitted and received from an interface unit such as a keypad of the wireless telephone body, and is long when data is transmitted and received through an external interface unit. The fourth method is a method in which the user operates the wireless telephone and declares that long data is transmitted and received. For example, the data length is short when the user does not press the "turbo button", and the data length is long when the user presses the "turbo button".

Of course, the present invention is not limited to the above example, and there are other methods for determining the data length to be transmitted / received. Therefore, the data length is determined by using an optimum method alone or by combining a plurality of methods. When it is determined that the data length to be transmitted / received is long as a result of the determination, a stricter level of congestion of the required base station is required to prevent data packet retransmission due to delay. Therefore, the base station selection unit of the control information reception unit 503 sets the base station selection threshold to the strictest congestion level C (S32, S33, S34), and determines the base station γ from the condition of (Table 1). select. In this way, when transmitting and receiving long data, by making the conditions for selecting the base station strict, it is possible to prevent the occurrence of retransmission due to the delay of the data packet. Note that steps S35 to S40 are steps S22 to S27 of FIG.
Therefore, the description thereof will be omitted.

As described above, according to the present embodiment, the communication amount measuring unit 403 for counting the number of packets processed within a fixed time and calculating the congestion degree of the base station 400 is provided, and the control information transmitting unit is provided. 404 is a packet processed within a certain time by notifying the wireless communication device of the congestion degree of the base station 400 calculated by the communication amount measuring unit 403 through the downlink control channel when performing wireless packet communication. By counting the number, the congestion degree of wireless packet communication can be determined, and the congestion degree can be notified to the wireless communication device via the control channel. Therefore, the congestion degree information notified via the control channel can be transmitted to the wireless communication device. The receiver can automatically select the base station that can obtain the optimum communication speed, and when transmitting data packets. It is possible to prevent a decrease in communication speed retransmission process by the delay results.

In addition, a base station selecting unit 503 for automatically selecting a base station to perform communication is provided, and when performing wireless packet communication, the receiving unit 502 notifies from the base station 400 on the downlink control channel. The base station selecting unit 503 receives the congestion degree of the base station 400 that has been set, and the base station selecting unit 503 selects a base station whose congestion degree of the received base station 400 is lower than a plurality of preset thresholds. The communication device can receive the congestion degree of the wireless packet communication notified from the base station 400 via the control channel, and by using the congestion degree, the base station is automatically selected to establish the wireless line. As a result, it is possible to automatically select the base station that can obtain the optimum communication speed, and at the time of transmitting the data packet, there is a retransmission process due to delay. It is possible to prevent a decrease in to the communication speed. Further, since the data packets are transmitted mainly to the wireless line which is not congested, the data packets are distributed to the entire base station system and the decrease of the communication speed due to the congestion can be prevented. Further, by simply adding a simple configuration (base station selection unit) to the wireless communication device, it is possible to automatically select the base station that provides the optimum communication speed.

Further, since the plurality of preset thresholds are determined by the data length to be transmitted / received, not only the congestion degree of the base station 400 but also the total length of the data to be transmitted / received. Can also be taken into account, so that it is possible to automatically select the base station that can obtain the optimum communication speed, and it is more effective to reduce the communication speed caused by retransmission processing due to delay when transmitting data packets. Can be prevented.

[0037]

As described above, according to the base station of the first aspect of the present invention, the transmitter for transmitting the downlink control channel to the plurality of wireless communication devices, and the uplink control channel from the plurality of wireless communication devices. In a base station having a receiving unit for receiving a communication channel, a communication unit for capturing a communication channel with a wireless communication device, and a control information transmitting unit having a channel selection unit for allocating the communication channel to the wireless communication device through a downlink control channel. , Counting the number of packets processed in a fixed time, equipped with a communication amount measuring unit for calculating the congestion degree of the base station, the control information transmitting unit, when performing wireless packet communication, through the downlink control channel, By notifying the wireless communication device of the congestion degree of the base station calculated by the communication amount measuring unit, the number of packets processed within a fixed time is counted, and To determine the congestion degree of Tsu door communication,
Since the degree of congestion can be notified to the wireless communication device via the control channel, the wireless communication device receives the congestion degree information notified via the control channel, so that the base station can obtain the optimum communication speed. It is possible to obtain the advantageous effect that the selection can be automatically performed, and at the time of transmitting the data packet, the reduction of the communication speed caused by the retransmission processing due to the delay can be prevented.

According to the second aspect of the present invention, there is provided a radio communication device, a transmission unit for transmitting the uplink control channel to the base station, a reception unit for receiving the downlink control channel from the base station, and a communication unit for capturing the communication channel. A wireless communication device having a packet communication unit that performs packet communication with a base station, and a data length determination unit that determines the length of data to be transmitted and received,
A base station selecting unit that automatically selects a base station that performs communication is provided, and when performing wireless packet communication, the receiving unit uses the degree of congestion of the base station notified from the base station on the downlink control channel. The base station selecting unit selects a base station whose congestion degree of the received base station is lower than a plurality of preset thresholds, so that the wireless communication device transmits the base station via the control channel. It is possible to receive the notified degree of congestion of wireless packet communication, and by using the degree of congestion, it is possible to automatically select a base station and establish a wireless line, thus obtaining an optimum communication speed. The advantageous effect that the base station can be automatically selected and, at the time of transmitting a data packet, a decrease in communication speed caused by a retransmission process due to a delay can be prevented is obtained. . Further, since the data packets are transmitted mainly to the wireless line that is not congested, the data packets are distributed to the entire base station system, and it is possible to prevent a decrease in communication speed due to congestion. Is obtained. In addition, an advantageous effect that the base station that can obtain the optimum communication speed can be automatically selected can be obtained simply by adding a simple configuration (base station selection unit) to the wireless communication device.

According to the wireless communication device of the third aspect, in the wireless communication device of the second aspect, the plurality of preset threshold values are determined by the data length to be transmitted and received. , Not only the congestion level of base stations,
Since it is possible to consider the situation of the total length of the data to be transmitted and received, it is possible to automatically select the base station that can obtain the optimum communication speed, and at the time of transmitting the data packet, the retransmission process due to the delay. It is possible to obtain an advantageous effect that it is possible to more effectively prevent a decrease in communication speed caused by.

[Brief description of drawings]

FIG. 1 is a block diagram showing a base station according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a mobile station (wireless communication device) according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a congestion degree notification operation by a base station.

FIG. 4 is a flowchart showing a conventional base station selection operation.

FIG. 5 is a flowchart showing a base station selection operation according to the first embodiment of the present invention.

[Explanation of symbols]

400 base stations 401, 501 antenna 402, 502 communication control unit 403 Communication amount measurement unit 404 Control information transmitter 405 Line control unit 500 mobile stations 503 Control information receiver 504 Input / output control unit 505 Data interface section 506 Data length judgment unit 600 circuit network

Claims (3)

[Claims] 1. A transmission unit for transmitting a downlink control channel to a plurality of wireless communication devices, a reception unit for receiving an upstream control channel from the plurality of wireless communication devices, and a communication unit for capturing a communication channel with the wireless communication device. , A base station having a control information transmission unit having a channel selection unit for allocating a communication channel to a wireless communication device through the downlink control channel, counting the number of packets processed within a fixed time, and congesting the base station. A communication amount measuring unit that calculates a degree, the control information transmitting unit, when performing wireless packet communication, through the downlink control channel, the congestion degree of the base station calculated in the communication amount measuring unit, the wireless communication A base station characterized by notifying the aircraft. 2. A transmission section for transmitting an uplink control channel to a base station, a reception section for receiving a downlink control channel from the base station, a communication section for capturing a communication channel, and packet communication with the base station as a partner. A wireless communication device having a packet communication unit and a data length determination unit that determines the length of data to be transmitted / received is provided with a base station selection unit that automatically selects a base station to perform communication, and performs wireless packet communication. In that case, the receiving unit receives the congestion degree of the base station notified from the base station on the downlink control channel, and the base station selecting unit sets the congestion degree of the received base station in advance. A radio communication device characterized by selecting a base station lower than a plurality of threshold values. 3. The wireless communication device according to claim 2, wherein the preset plurality of threshold values are determined by a data length to be transmitted / received.