JPH10308752A - Communication device and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform allocation of radio resources taking a media attribute into consideration/release of connections and to efficiently operate radio resources. SOLUTION: A resources allocation controlling means 3 performs allocation control of radio resources based on a connection service attribute, etc., when a radio terminal 41 which is subordinate to a base station 21 moves and makes requests of new/addition/change of a communication connection or when a resource management cell performs congestion notification. This makes possible to appropriately (re) allocate radio resources, taking a media attribute into consideration and therefore, to efficiently operate radio resources.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication device and a communication system for providing, for example, multimedia services.

[0002]

2. Description of the Related Art In a radio base station, when setting a communication path with a subordinate radio terminal, each radio base station assigns radio resources such as a spread code in a CDMA system and a time division slot in a TDMA system. The radio resources that can be allocated vary depending on the capacity of the terminal (or communication connection) of the radio base station, the amount allocated to the accommodation terminal at each time, and the like. Therefore, for example, when the wireless base station to be used is switched by the wireless terminal moving between the wireless base stations, the wireless resources allocated in the base station before the movement are not necessarily allocated in the base station of the movement destination. It is not always possible. For example, by using a plurality of spreading codes at the same time (multi-code transmission) in the CDMA system, a terminal that has performed communication while securing a certain band can be assigned the same number of spreading codes even at a destination base station. Is not always possible,
A fixed band used in the base station before the movement cannot be secured. The effect of this on the communication connection depends on the constraints on the connection delay and discard, ie, the service attributes. For example, there are large restrictions on the available bandwidth for connections used for continuous media such as voice and video, which have large restrictions on delay time or fluctuations, but use them for connections used for data communication. The constraints on the band are not necessarily large.

[0003] However, in the prior art, when the base station allocates radio resources to a communication connection, the media attribute of the connection as described above is not considered. Therefore, in the case where a certain band is used by the above-mentioned multi-code transmission, for example, the same number of spreading codes cannot be allocated by switching the base station, and the band used before moving cannot be secured. in case of,
Regardless of the attribute of the media of the connection, there is no choice but to make a call loss or to continuously maintain the bandwidth with a small bandwidth. The allocation of radio resources to such a connection is performed in each case of a connection addition / new setting request, a handover between base stations, and a band change request from a terminal. No assignment has been made in consideration of

For example, in an ATM network, an RM (Resource M) depends on a media attribute.
An in-network resource management information called an "analysis" cell is defined, and there is a mechanism for restricting transmission or promoting transmission to a terminal. The terminal reduces or increases the information transmission rate according to the in-network resource management information, but even in this case, the information is not reflected in the method of allocating the radio resources to the connection.

[0005]

As described above, in the conventional radio system, the radio resources for the connection performed in the case of a connection addition / new setting request from a terminal, a handover between base stations, a band change request, and the like. At the time of the assignment, no assignment was made in consideration of the media attribute. The following problems have been caused by allocating radio resources / releasing connections without considering such media attributes.

[0006] Even if a connection is set. In some cases, the minimum quality required by the media used in the connection cannot be provided.

[0007] Even when the minimum quality required by the media can be provided, connection setting may not be performed.

[0008] The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to provide a radio communication system for allocating radio resources in consideration of media attributes.

Another object of the present invention is to provide a radio communication system for preventing the radio resource from being unnecessarily allocated by not changing the radio resource allocation when the information transmission rate from the terminal is reduced due to the congestion notification from the network or the input restriction. It is to provide a system.

[0010]

According to one aspect of the present invention, there is provided a communication apparatus for performing communication with a wireless terminal via a wireless transmission path, wherein the communication apparatus communicates with the wireless terminal. Means for allocating wireless resources for each communication connection used by the wireless terminal based on a service attribute of the communication connection and assignable wireless resources.

According to a second aspect of the present invention, there is provided a communication apparatus for performing communication with a wireless terminal via a wireless transmission path, wherein the communication apparatus receives a request for adding a communication connection from the wireless terminal using the transmission path. Means for allocating radio resources based on the service attribute of the additional connection and the allocable radio resources.

According to a third aspect of the present invention, there is provided a communication apparatus for performing communication with a wireless terminal via a wireless transmission path, wherein the wireless terminal requests a change of a bandwidth of a connection in use using the transmission path. A means for allocating a radio resource based on a service attribute of the connection and an allocatable radio resource. According to a fourth aspect of the present invention, there is provided a communication apparatus which is connected to a network and communicates with a wireless terminal via a wireless transmission path, and performs at least congestion notification information or information loss for a specific communication connection from the network. When receiving the information, the information processing apparatus further comprises means for changing the assignment of radio resources to the communication connection.

According to a fifth aspect of the present invention, there is provided a communication apparatus for performing communication with a wireless terminal via a wireless transmission path, wherein when a wireless resource allocated to a communication connection used by the wireless terminal increases or decreases. Means for re-allocating radio resources according to the service attribute of the communication connection.

According to a sixth aspect of the present invention, there is provided the communication apparatus according to the first or second aspect, wherein the radio resource uses a code division multiple access system using a spreading code.

According to a seventh aspect of the present invention, in the communication apparatus according to the first or second aspect, the radio resource uses a time division multiple access method using a time division slot.

The present invention according to claim 8 is a communication system having a wireless terminal and a wireless base station for communicating with the wireless terminal via a wireless transmission path, wherein the wireless base station comprises:
When communicating with the wireless terminal, the wireless terminal has means for notifying the wireless terminal of information generated based on assignable wireless resources and requesting permission or regulation of data transmission, the wireless terminal comprising: It is characterized by having means for transmitting or regulating information based on the notification received from the base station.

According to a ninth aspect of the present invention, there is provided a communication system having a wireless terminal and a wireless base station communicating with the wireless terminal via a wireless transmission path, wherein the wireless base station comprises:
Having means for setting the number of times of retransmission control based on a service attribute for each communication connection used by the wireless terminal,
The wireless terminal has means for setting the number of times of retransmission control based on a service attribute for each communication connection to be used. The present invention according to claim 10 is a communication system having a wireless terminal and a wireless base station that communicates with the wireless terminal via a wireless transmission path, wherein the wireless base station is used by the wireless terminal. The wireless terminal has means for setting a code length of an error correction code based on a service attribute of each communication connection, and the wireless terminal has means for setting a code length of the error correction code based on a service attribute of each communication connection to be used. It is characterized by having.

In the communication apparatus according to the first, sixth, and seventh aspects of the present invention, when the radio base station allocates radio resources to the radio terminals under its control, the radio base station performs the radio communication based on the service attribute of the connection. Since the resource allocation is controlled, the radio resources can be allocated appropriately, and therefore, a handover that provides a connection suitable for the medium can be performed.

In the communication apparatus according to the second, sixth, and seventh aspects of the present invention, when a wireless terminal under the control of the wireless base station requests an additional allocation of wireless resources, the wireless terminal is based on the service attribute of the connection. Since the allocation control of the wireless resources is performed by using the wireless resources, it is possible to appropriately perform the additional allocation of the wireless resources, and therefore, it is possible to provide a connection suitable for the medium.

In the communication apparatus according to the third aspect of the present invention, when a wireless terminal under the control of the wireless base station requests a change of the bandwidth of the connection being used, the requested bandwidth change request is issued. Since the allocation of the radio resources is controlled based on the service attribute of the connection whose band is to be changed, the radio resources can be appropriately allocated, and therefore, a connection suitable for the medium can be provided.

In the communication apparatus according to the present invention, when a congestion notification is given to the connection from the network, the transmission rate is reduced in the radio terminal in consideration of the service attribute of the notified connection. Therefore, by reallocation of the radio resources, it is possible to efficiently allocate the radio resources. At the same time, even when the radio terminal itself does not have a function corresponding to the notification, the radio base station allocates the radio resources. By controlling, the wireless base station can control the transmission rate instead of the terminal.

In the communication apparatus according to the fifth aspect of the present invention, if the radio resources that can be allocated increase or decrease after the radio resources are once allocated to the radio terminals under the control of the radio base station, the radio resources are increased or decreased. Accordingly, even for a communication connection that has already been allocated, radio resource allocation control is performed again based on the service attribute of the connection and the original report parameters, so that radio resources can be allocated appropriately, and It is possible to provide a suitable connection.

In the communication system according to the present invention, when the radio base station communicates with the radio terminal, the radio base station transmits information requesting permission or restriction of transmission of data generated based on allocatable radio resources. Notify the wireless terminal,
Since the wireless terminal sends or regulates information based on the notification, even during communication, it can respond to the connection addition request / band change request, and at the same time, the requested connection / band change target connection Since the radio resource allocation control is performed again based on the service attribute, the radio resources can be appropriately allocated, and
It is possible to provide a connection suitable for media.

In the communication system according to the ninth aspect of the present invention, when the radio base station communicates with the radio terminal, the radio base station determines the number of retransmissions according to the required quality of service, and performs the retransmission process for the number of retransmissions. Therefore, while it is possible to provide the required service quality, it is possible to select an error recovery capability by retransmission control, and as a result, efficient operation of radio resources becomes possible.

In the communication system according to the present invention, when the radio base station communicates with the radio terminal, the radio base station determines a redundant bit length according to a required quality of service, and according to the redundant bit length. Since the error control is performed, the required service quality can be provided.On the other hand, even when retransmission control is not suitable due to a round trip time of information transmission or the like, the error recovery capability by the error correction control can be effectively selected, As a result, efficient operation of radio resources is enabled.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram showing a configuration of a wireless communication system according to one embodiment of the present invention. As shown in the figure, ATM (Asynchronous Transf)
erMode) wireless base stations 21 and 22 having wireless transmission / reception means are connected via a network 1. The radio base stations 21 and 22 have resource allocation control means 31 and 32, respectively. In each service area of the wireless base stations 21 and 22, a wireless terminal 41 is provided.
And 42 are present. A wired terminal 5 is connected to the ATM network 1. The wireless terminals 41 and 42 and the wireless base stations 21 and 22 are, for example, CDMA (Code Division Multi) via wireless transmission paths.
ple Access) system or TDMA (Tim
e Division Multiple Accesses
s) Communication can be performed with each other in a system. Furthermore, since both the wireless base stations 21 and 22 are connected to the ATM network 1, the wireless terminals 41 and 42
Can communicate with each other via the wireless base station 21, the ATM network 1, and the wireless base station 22. Also,
The wired terminal 5 directly connected to the ATM network 1 can also communicate with the wireless terminals 41 and 42.

FIG. 2 is a conceptual diagram showing the configuration of the resource allocation control means 31 provided in the radio base station 21.

As shown in the figure, the resource allocation control means 31 has the following three tables, and has a function of performing resource management and resource allocation control using these tables.

Code allocation management table 310 Code number-bandwidth correspondence table 311 Code allocation rule table 312 for each service attribute The code allocation management table 310 communicates with each base station via a wireless transmission path under the jurisdiction of each base station. Is a table for managing all the terminals that are communicating with each other and the status of the communication resources allocated to the terminals, and is expressed as information in a table format corresponding to these data. Specifically, a terminal i which is an identifier of all terminals to which codes for communication have been assigned from the radio base station.
d (identifier) is enumerated, and for each connection connecting the terminal and the radio base station, a connection id which is an identifier of the connection, a service attribute which is a constraint condition regarding delay and discard of the connection, and One line is configured in such a manner that the number of allocated codes corresponds to each other, and the last line has the number of codes that can be newly allocated, that is, the number of available code resources as information. Each radio base station has 31
It has a code assignment management table such as 0. FIG. 3 is a configuration diagram illustrating an example of a code assignment management table of a certain wireless base station. As shown in the figure,
A plurality of terminals including the wireless terminals 41 and 42 communicate with the wireless base station while securing a communication band. The terminal 41 has two connections A1 and B1 as this communication band, and the connection A1 has "UB" as a service attribute.
R (Unspecified Bit Rate) "is defined, and one code is assigned. The connection B1 has a service attribute “ABR (Avail
Able Bit Rate) "and two codes are assigned. Similarly, the terminal 42 has two connections A2 and B2, and the connection A2 has "ABR (Available B
it Rate) ", two codes are allocated, and connection B2 has" CB "as a service attribute.
R (Constant Bit Rate) "is defined, and three codes are assigned. Note that "UB
Each of "R", "ABR" and "CBR" represents a service class defined in the ATM communication system. The data in the code allocation management table 310 is rewritten each time the communication band is allocated, additional allocated, the band is changed, or the allocation is changed based on the congestion notification information.

The number-of-codes / bandwidth correspondence table 311 indicates that the maximum value of the number of codes that can be allocated in each radio base station (equal to the above-mentioned “number of codes that can be newly allocated”) is given. 9 is a table in which the number of codes used at the same time (“the number of allocated codes”) is associated with a usable band in the multicode system. That is, if the maximum value of the number of codes that can be allocated is specified, which band to use for communication in the multi-code system is uniquely determined for each number of simultaneously used codes. It is stored in the band correspondence table 311. Each wireless base station has a code number-band correspondence table such as 311. FIG. 4 is a conceptual diagram showing an example of a code number-band correspondence table in a certain radio base station. As shown in the drawing, when the maximum value of the number of codes that can be allocated, that is, the number of codes that can be newly allocated is Tn1, and the number of simultaneously used codes, that is, the number of allocated codes is 1, BW
11 indicates that the band BW21 can be used if the number of simultaneously used codes is 2, and the band BW31 can be used if the number of simultaneously used codes is 3. Similarly, the maximum number of assignable codes is Tn
If the number of simultaneously used codes is 1, the band BW12 is used, and if the number of simultaneously used codes is 2, the band BW22 is used.
However, if the number of simultaneously used codes is 3, the band BW32 can be used. This code number-band correspondence table 31
The data of No. 1 is rewritten as necessary according to the allocation of the communication band, the additional allocation, the change of the band, the change of the allocation by the congestion notification information, and the like.

The service attribute-based code assignment rule table 312 is information common to one communication network as a whole, and refers to information in which, when a communication resource is assigned, a code assignment rule is associated with each media attribute related to the communication. . Specifically, when assigning a code as a communication resource, CBR which is a service class (service attribute) defined in the ATM communication system of the code is used.
(ConstantBit Rate), VBT (Va
removable Bit Rate), ABR (Avai
label Bit Rate), UBR (Unspe
certifiedBitRate),
6 is a table in which a condition for assigning codes and a number of codes to be assigned are associated with each other in a table format. The assignment condition and the number of assigned codes together constitute a code assignment rule. Each wireless base station has a service attribute-based code assignment rule table such as 312. FIG. 5 is a conceptual diagram showing an example of a code assignment rule table for each service attribute in a certain radio base station. In the example shown in FIG.
The assignment rule when the service attribute has a service attribute of “BR (Constant Bit Rate)” is that the assignment condition for the code is “providable band ≧ PCR”, and the number of assigned codes is the Is defined as the smallest of these. The media to be communicated is "VBT (Variable Bit)
Rate) ”, the assignment rule for the code is“ providable bandwidth ≧
PCR ", and the number of allocated codes is defined as the minimum number of codes satisfying the" providable band≥PCR ". The media to be communicated is "ABR (Avai
The allocation rule when the service attribute has a service attribute of “table Bit Rate)” is such that the allocation condition for the code is “PCR ≧ available band ≧ MCR”, and the number of allocated codes is a code that satisfies the “PCR ≧ available band ≧ MCR”. Is defined as the maximum number of The media to be communicated is "UBR (Unspecified)
BitRate) ”, the assignment rule for the code is that the allocation condition for the code is“ providable band> 0 ”, and the number of allocated codes is the maximum number of codes that satisfy the“ providable band> 0 ”. Is defined as This service attribute-specific code assignment rule table 3
Twelve data are predetermined, but can be rewritten as needed.

Next, the operation according to the first embodiment of the present invention will be described.

As shown in FIG. 1, it is assumed that a wireless terminal 41 that has been communicating using two connections under the wireless base station 21 moves from under the control of the base station 21 to under the control of the base station 22. I do. The radio base stations 21 and 22 have resource allocation units 31 and 32, respectively. As described above, the resource allocating unit 31 stores the code allocation management table 310, the code number-band correspondence table 311 and the code allocation rule table 312 for each service attribute.
The resource allocation unit 32 includes a code allocation management table 320 (not shown), a code number-bandwidth correspondence table 321.
And a service attribute-based code assignment rule table 322. It is assumed that the service attribute-based code assignment rule tables 312 and 322 have the same data as that shown in FIG. 5 as data common to the entire communication network.

First, the wireless terminal 41 communicates with the wireless base station 21 by securing a band by simultaneously using a plurality of CDMA spreading codes (multi-code system). The number of connections used for communication is two, and has the following configuration.

Connection A: The service class (service attribute) is ABR (Available Bit R).
ate), the declaration parameter at the time of call setup is PCR (Pe
akCell Rate) is a PCR-A (Cells /
sec. ), MCR (Minimum Cell Ra)
te) uses an MCR-A (Cells / sec.) multi-code transmission system using two spreading codes at the same time.

Connection B: The service class (service attribute) is CBR (Constant Bit Ra).
te), the declaration parameter at the time of call setup is PCR
-B (Cells / sec.), A multi-code transmission system using three spreading codes at the same time is used.

When the radio terminal 41 moves under the control of the base station 22 while continuing the communication using the connections A and B, the base station 22 refers to the code assignment management table 320 and finds that the Assume that the resource has only one code. Further, the code number-band correspondence table 32
1, as a result, the available bandwidth is RATE2 (RA
It is assumed that TE2> MCR-A and RATE2 <PCR-B). Here, according to the service attribute code assignment rule table 322, the service class ABR to which the connection A to which the wireless terminal 41 was originally assigned belongs.
Indicates that the code assignment condition is “PCR ≧ suppliable band ≧
MCR ". On the other hand, the service class CBR to which the connection B to which the wireless terminal 41 was originally assigned belongs.
Indicates that the code assignment condition is “providable band ≧ PC
R ". Therefore, of the two connections A and B used by the wireless terminal 41 under the control of the base station 21,
The connection A satisfies the report parameters and the service attributes, but the connection B cannot satisfy the report parameters. Therefore, it can be determined that even if the connection is established, the quality satisfactory by the user cannot be provided. Therefore, the resource allocation control means 32 of the base station 22
Assigns one code that can be assigned to connection A, and releases connection B.

As described above, according to the present embodiment, even when a wireless terminal that has been communicating using a connection under a certain base station moves to another base station, the service attribute of the connection is not changed. By performing the radio resource allocation control based on the radio base station, the radio resources can be appropriately allocated even under the control of the another base station. Therefore, according to the present invention, it is possible to perform a handover that provides a connection suitable for a medium transmitted by the connection.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the technical idea of the present invention.

For example, in the above embodiment, the CDMA
Although the case where the bandwidth is secured by the multi-code transmission method described above, the multi-slot method of securing the bandwidth by using a plurality of time-division slots may be used in, for example, TDMA.

Next, the operation according to the second embodiment of the present invention will be described.

The configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, the wireless terminal 41 uses a plurality of CDMA spreading codes simultaneously under the And secure communication. At this time, it is assumed that the wireless terminal 41 makes a new connection setting request under the base station 21. The wireless base station 21 has a resource allocating unit 31. As described above, the resource allocation unit 31 includes the code allocation management table 310, the code number-bandwidth correspondence table 311 and the code allocation rule table 312 for each service attribute. Here, it is assumed that the wireless terminal 41 requests to newly set two connections. The breakdown of the requested connection is as follows.

Connection A: service class is AB
In R (Available Bit Rate), the declaration parameter at the time of call setup is PCR (Peak Cell).
Rate) is PCR-A (Cells / sec.), M
CR (Minimum Cell Rate) is MCR
-A (Cells / sec.), A multi-code transmission method using two spreading codes at the same time is used.

Connection B: service class is CB
In R (Constant Bit Rate), the report parameter at the time of call setup is PCR-B (Cells
/ Sec. ), A multi-code transmission system using three spreading codes at the same time is used.

Radio base station 21 accommodating radio terminal 41
It is assumed that as a result of referring to the code assignment management table 310 of the own station, the assignable code resources are two codes. Also, as a result of referring to the code number-band correspondence table 311, the band that can be provided by the codes that can be allocated is RATE1 (RATE1> MCR-A and RATE1 <
PCR-B). Here, according to the service attribute-based code assignment rule table 312, the wireless terminal 41
Of the service class ABR to which the connection A for which the communication allocation request is made belongs to “PC
R ≧ suppliable band ≧ MCR ”. On the other hand, the wireless terminal 4
Service class CBR to which connection B, which is another connection requesting communication allocation 1 belongs, belongs
Indicates that the code assignment condition is “providable band ≧ PC
R ". Accordingly, among the connections for which a setting request has been made, connection A satisfies the report parameters and service attributes, but connection B does not satisfy the report parameters. Cannot be provided. Therefore, the resource allocation control means 31 of the base station 21 refers to the service attribute-based code allocation rule table 312, allocates two codes that can be allocated to the connection A, and does not allocate the connection B (therefore, no connection is set). It shall be.

As described above, according to the present embodiment, when a wireless terminal makes a new connection setting request under a certain base station, the wireless resource allocation control is performed based on the service attribute of the requested connection. , Radio resources can be more appropriately allocated. Therefore, according to the present invention, it is possible to provide a connection suitable for the medium transmitted by the connection.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical concept of the present invention.

For example, in the above embodiment, the CDMA
Although the case where the bandwidth is secured by the multi-code transmission method described above, the multi-slot method of securing the bandwidth by using a plurality of time-division slots may be used in, for example, TDMA.

Next, the operation according to the third embodiment of the present invention will be described.

The overall configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, the radio terminal 41 uses a plurality of CDMA spreading codes at the same time under the radio base station 21. It is assumed that communication can be performed while securing a band. At the same time, it is assumed that information transmitted through the communication connection set in the first embodiment is divided into fields for storing user information and control information, respectively. That is, if a communication connection is set, it is assumed that an associated control channel capable of transmitting and receiving control information between the wireless terminal and the wireless base station is provided for each communication connection. The associated control channel can be provided, for example, by the following method.

In the CDMA system, information transmitted / received with the same spreading code is divided into fields and provided.

In the CDMA system, a spreading code different from user information is allocated and provided.

In the TDMA system, a time division slot different from user information is allocated and provided. At this time, it is assumed that the wireless terminal 41 communicating with the base station 21 issues a connection additional setting request. The wireless base station 21 has a resource allocating unit 31. As described above, the resource allocating unit 31 includes the code allocation management table 310, the code number-bandwidth correspondence table 311
And a service attribute-based code assignment rule table 312.

As a result of the operation in the second embodiment,
It is assumed that the terminal 41 that has been communicating with one connection (connection A) set later requests further connection setting. Such a connection addition setting request during communication is made using the associated control channel. The details of the connection for which the additional setting request has been made are as follows.

Connection B: service class is CB
In R, the report parameter PCR is PCR-B (Cells /
sec. ).

At the time of this connection addition request,
The wireless base station 21 can allocate three CDMA spread codes as a result of referring to the code assignment management table 310 of the own station, and can provide the CDMA spread code with an assignable code as a result of referring to the code number-band correspondence table 311. It is assumed that the band is RATE2 (> PCR-B). Here, according to the service attribute-based code assignment rule table 312, the service assignment CBR to which the connection B to which the wireless terminal 41 has made an additional setting request belongs has a code assignment condition of “providable bandwidth ≧ PCR”. Therefore, it means that the report parameter can be satisfied for the connection B for which an additional setting request has been issued from the wireless terminal 41. Therefore, the resource allocation control means 31 of the base station 21 uses the service attribute-based code allocation rule table 31.
Referring to FIG. 2, three assignable codes are assigned to connection B.

As described above, according to the present embodiment, a connection addition request from a wireless terminal can be accepted even during communication, and the connection addition request can be accepted based on the service attribute of the requested connection. By performing radio resource allocation control, appropriate radio resource allocation can be performed. Therefore, according to the present invention, it is possible to additionally provide a connection suitable for the media. Note that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical idea of the present invention.

For example, in the above-described embodiment, the CDMA
The method realized by code assignment in the scheme has been described. For example, in the TDMA scheme, time division slot assignment may be used.

Next, an operation according to the fourth embodiment of the present invention will be described.

The overall configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, the radio terminal 41 uses a plurality of CDMA spreading codes at the same time under the radio base station 21. It is assumed that communication can be performed while securing a band. At the same time, it is assumed that information transmitted through the communication connection set in the first embodiment is divided into fields for storing user information and control information, respectively. That is, if a communication connection is set, it is assumed that an associated control channel capable of transmitting and receiving control information between the wireless terminal and the wireless base station is provided for each communication connection.

At this time, it is assumed that the wireless terminal 41 communicating with the base station 21 changes the band of the connection being used. The wireless base station 21 has a resource allocating unit 31. Resource allocation means 3
1 is the code assignment management table 31 as described above.
0, a code number-bandwidth correspondence table 311 and a code assignment rule table 312 for each service attribute.

As a result of the operation in the third embodiment,
A state where communication is performed in a state where two connections (connection A and connection B) are set is defined as an initial state. In this state, it is assumed that the terminal 41 later makes a request to increase the bandwidth of the connection B in use to RATE3 (> RATE2). Such a bandwidth change request during communication is made using the above-mentioned associated control channel. At the time of this band change request, the radio base station 21 refers to its own code allocation management table 310, and as a result, the code that can be additionally allocated by the base station 21 is 1
If there is a code and the code is allocated and the multi-code transmission is performed together with the code currently allocated to the connection B, the RATE3 can be satisfied as a result of referring to the code number-bandwidth correspondence table 311. Therefore, the resource allocation control means 31 of the base station 21 refers to the service attribute-based code allocation rule table 312 and allocates one more code to the connection B in response to the bandwidth change request.

As described above, according to the present embodiment, it is possible to receive a band change request for a connection during communication even during communication, and
By performing radio resource allocation control based on the requested band and the service attribute of the connection whose band is to be changed, radio resources can be allocated appropriately. Therefore, according to the present invention, it is possible to provide a connection suitable for media.

Next, the operation according to the fifth embodiment of the present invention will be described.

The overall configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, the radio terminal 41 uses a plurality of CDMA spreading codes at the same time under the radio base station 21. It is assumed that communication can be performed while securing a band. At the same time, it is assumed that information transmitted through the communication connection set in the first embodiment is divided into fields for storing user information and control information, respectively. That is, if a communication connection is set, it is assumed that an associated control channel capable of transmitting and receiving control information between the wireless terminal and the wireless base station is provided for each communication connection.

At this time, it is assumed that radio resources are allocated corresponding to resource management cells (RM cells) in service class ABR. The wireless base station 21 has a resource allocating unit 31. The resource allocation means 31
As described above, the code assignment management table 310, the code number-band correspondence table 311 and the service attribute-based code assignment rule table 312 are provided.

Under the wireless base station 21, the wireless terminal 41
It is assumed that the following ABR service class communication is performed by the multi-code scheme using two spreading codes in the DMA scheme.

Connection A: ABR, report parameter PCR is PCR-A, and MCR is MCR-A.

In this state, it is assumed that the congestion notification by the RM cell is made from the ATM network 1 to the connection A.

The congestion notification is also interpreted by the resource allocation control means 31 in the base station 21. Even if the code assigned to connection A is one, the MCR value MCR of the report parameter of connection A
-It is assumed that a band equal to or higher than A can be provided. At this time, according to the service attribute-based code allocation rule table 312, the code allocation condition of the service class ABR to which the connection A related to the congestion notification by the RM cell belongs is “PCR ≧ available bandwidth ≧ MCR”. Therefore, the resource allocation control means 31 in the base station 21 allocates only one code to the connection A.

As described above, according to the present embodiment, even when congestion notification is made by an RM cell for an connection from the ATM network, the service class of the connection for which the RM cell notification has been made is taken into consideration, and In the wireless terminal, in order to reduce the transmission rate, the wireless resources can be efficiently allocated by reallocating the wireless resources. Further, according to the present invention, even when the wireless terminal itself does not have a function corresponding to the RM cell, the wireless base station controls the transmission rate on behalf of the terminal by controlling the wireless resource allocation in the wireless base station. It is also possible.

In the above operation example, the case where the congestion notification is made from the ATM network 1 is taken up. However, when the congestion ends, the RM of the type which prompts the increase of the transmission rate is used.
In some cases, cells are sent from the ATM network 1.
In such a case as well, the resource allocation control means 31 in the base station 21 performs control for efficiently allocating the radio resources by changing (in this case, increasing) the number of codes allocated to the radio terminals 41 in the same manner as described above. In addition, it is possible to improve communication quality.

The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the technical concept of the present invention.

For example, in the above embodiment, the CDMA
The example of realization by multi-code transmission in the system was shown.
For example, even when the TDMA scheme is used, similar resource (in this case, time-division slot) allocation control may be performed for multi-slot transmission.

Next, the operation according to the sixth embodiment of the present invention will be described.

The overall configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, the radio terminal 41 uses a plurality of CDMA spreading codes at the same time under the radio base station 21. It is assumed that communication can be performed while securing a band.

At this time, the service class UBR (Uns
Communication using guaranteed bit rate (QoS) and other QOS (Quality Of Service)
Suppose a case where radio resources are allocated to both connections whose quality is strict.

It is assumed that the radio base station 21 accommodates one or more connections that are strict in QOS quality. In this situation, it is assumed that the wireless terminal 41 requests communication using the service class UBR under the wireless base station 21.

In general, when the number of codes assigned to a base station increases, there is a possibility that the communication quality that can be provided in a connection to which a code has been assigned may decrease as a whole. QO
If a large number of codes are assigned to UBR communication in a situation where codes are assigned to connections strict in S, quality required for connections strict in QOS may not be provided. Therefore, a code cannot be assigned to UBR communication without limit. Therefore, in the present embodiment, the radio base station 21 uses the UBR with the following probability, for example.
Communication shall be allowed.

(Number of codes that can be assigned by base station 21)
-Number of codes currently allocated) / Number of terminals under the control of base station 21 In the example of this probability value, it is assumed that there is a possibility that a UBR communication request with one code per terminal may occur, and this calculated value is If it exceeds 1, it is treated as a value of 1 (a UBR communication request is allowed). According to the formula for calculating the probability, no change is made to the already assigned connection strict in the QOS quality accommodated in the radio base station 21, and the connection for newly requested communication is limited. You.

Therefore, according to the present embodiment, the service class UBR (Unspecified Bit Rat)
e) and other QOS (Quality Of
Service) When allocating radio resources to both connections with severe quality, restrict radio resources to be allocated to UBR communication so that the radio base station has a small influence on communication to which code resources have already been allocated. Is statistically possible, and efficient radio resource allocation can be performed.

Next, a seventh embodiment of the present invention will be described.

The overall configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, a radio terminal 41 uses a plurality of CDMA spreading codes at the same time under a radio base station 21. It is assumed that communication can be performed while securing a band.

FIG. 6 is a conceptual diagram showing respective configurations of a radio terminal and a radio base station in the radio communication system according to the seventh embodiment of the present invention. As shown in the figure, the radio base station 21 has a resource allocation unit 31 and a retransmission control unit 61. The wireless terminal 41 has a retransmission control unit 62
have.

FIG. 7 is a conceptual diagram showing the configuration of the retransmission control means.

As shown in the figure, the retransmission control means 6 has the following tables and means. The service quality-retransmission number correspondence table 7 The retransmission processing unit 8 The retransmission control unit 61 of the radio base station 21 includes a service quality-retransmission number correspondence table 71 (not shown) and a retransmission processing unit 81. The retransmission control unit 62 of the wireless terminal 41 includes a service quality-retransmission number correspondence table 72 (not shown) and a retransmission processing unit 82.

Service Quality-Retransmission Number Correspondence Table 7
Is a table showing the correspondence between the requested service quality and the number of retransmissions, and is expressed as information in a table format in which these data are associated with each other. Specifically, all possible levels of required quality of service are listed,
One line is composed of the number of retransmissions corresponding to the service quality level.

FIG. 8 is a configuration diagram showing an example of such a service quality-retransmission count correspondence table 7. As shown in FIG. As shown in the figure, the requested quality of service is BE in this example.
It is represented by being converted into a numerical value as R (Bit Error Rate), and the number of retransmissions corresponding to each BER value is defined. In this example, BER value 1
The number of retransmissions corresponding to 0 ^-3 , 10 ^-4 and 10 ^-5 is RT1, RT2 and RT3, respectively.

The retransmission processing unit 8 performs retransmission processing for the number of retransmissions determined by the service quality-retransmission number correspondence table 7.

At this time, the required BER (Bit
It is assumed that retransmission control is performed in accordance with Error Rate.

It is assumed that under the control of the radio base station 21, the radio terminal 41 performs communication requesting that the BER value, which is the quality of service, be BER1. Here, BER1 is given as one of the report parameters. Radio base station 21
The retransmission control means 61 in the above refers to the service quality-retransmission number correspondence table 71, and sets the value of the number of retransmissions corresponding to BER1, which is the service quality requested by the wireless terminal 41, as the maximum number of retransmissions. Similarly, the retransmission control unit 62 in the wireless terminal 41 determines the maximum number of retransmissions by referring to the service quality-retransmission number correspondence table 72. Then, the retransmission control means 61 in the radio base station 21
Is the maximum number of retransmissions determined above,
Communication is performed while performing retransmission control according to 1. Similarly, the retransmission control means 62 in the wireless terminal 41 performs communication for the determined maximum number of retransmissions while performing retransmission control by the retransmission processing unit 82.

As described above, according to the present embodiment, the number of retransmissions is determined according to the required service quality (here, BER), and the retransmission process is performed for the number of retransmissions. On the other hand, error recovery capability by retransmission control can be selected, and as a result, efficient operation of radio resources can be achieved.

Next, an eighth embodiment of the present invention will be described.

The overall configuration of the system is the same as that of the first embodiment. As shown in FIG. 1, the wireless terminal 41 uses a plurality of CDMA spreading codes at the same time under the wireless base station 21. It is assumed that communication can be performed while securing a band. The wireless base station 21 has a resource allocation unit 31 and an error control unit 91 (not shown). The wireless terminal 41 has an error control unit 92.
The error control means 91 of the radio base station 21 includes a service quality-error control code length correspondence table 1 (not shown).
01 and an error processing unit 111. The error control means 92 of the wireless terminal 41 includes a service quality-error control code length correspondence table 102 (not shown) and an error processing unit 112.

The service quality-error control code length correspondence table 10 is a table showing the correspondence between the required service quality and the error control code length, and is expressed as information in a table format in which these data are associated with each other. You. Specifically, all possible levels of the requested service quality are listed, and one line is composed of the error control code length corresponding to the service quality level.

FIG. 8 is a diagram showing an example of such a service quality-error control code length correspondence table 10. As shown in FIG. As shown in the figure, the requested quality of service is expressed as a BER (Bit Error Rate) converted into a numerical value in this example, and the number of retransmissions corresponding to each BER value is defined. In this example, BE
Error control code lengths corresponding to the R values 10 ⁻³ , 10 ⁻⁴ and 10 ⁻⁵ are EC1, EC2 and EC3, respectively.

The error processing section 11 performs error processing according to the error control code length determined by the service quality-error control code length correspondence table 10.

At this time, the required BER (Bit
It is assumed that error control is performed in accordance with (Error Rate).

As in the case of the retransmission control in the seventh embodiment, it is assumed that the radio terminal 41 performs communication under the radio base station 21 requesting that the BER value, which is the service quality, be BER1. . Here, BER1 is given as one of the report parameters. The error control means 91 in the wireless base station 21 refers to the service quality-error control code length correspondence table 101, and sets the value of the error control code length corresponding to BER1, which is the service quality requested by the wireless terminal 41, as the redundant bit length. I do. Similarly, the error control means 92 in the wireless terminal 41 performs the service quality-
By referring to the error control code length correspondence table 102, the redundant bit length is determined. The error control means 91 in the wireless base station 21 performs error control according to the determined redundant bit length by the error processing unit 11.
The communication is performed while the communication is performed by 1. Similarly, the error control unit 92 in the wireless terminal 41 performs error control according to the determined redundant bit length by the error processing unit 11.
The communication is performed while the communication is performed by 1.

As described above, according to the present embodiment, the redundant bit length is determined according to the required quality of service (here, BER), and error control is performed according to the redundant bit length. While providing service quality, you can select error recovery capability by error correction control,
As a result, efficient operation of radio resources is enabled. Further, since the error correction control is used, even when retransmission control is not suitable due to a round trip time of information transmission or the like, an error recovery capability can be effectively selected, and efficient operation of radio resources can be performed.

[0102]

As described in detail above, according to the first, sixth and seventh aspects of the present invention, when a radio base station allocates radio resources to radio terminals under its control, Since radio resource allocation control is performed based on the service attribute of the connection, radio resource allocation can be performed appropriately, and therefore, handover that provides a connection suitable for media can be performed.

According to the second, sixth, and seventh aspects of the present invention, when a wireless terminal under the control of a wireless base station requests additional allocation of wireless resources, the wireless terminal is determined based on the service attribute of the connection. Since the allocation control of the radio resources is performed, the radio resources can be additionally allocated appropriately, so that a connection suitable for the medium can be provided.

According to the third aspect of the present invention, when a wireless terminal under the control of a wireless base station requests a change in the bandwidth of a connection being used, the requested bandwidth change request is issued in response to the bandwidth change request. Since the radio resource allocation is controlled based on the service attribute of the connection whose band is to be changed, the radio resource can be appropriately allocated, and therefore, a connection suitable for the medium can be provided.

According to the present invention, when a congestion notification for a connection is made from the network, the transmission rate is reduced in the radio terminal in consideration of the service attribute of the notified connection. By reallocating the radio resources, the radio resources can be efficiently allocated, and the radio base station controls the radio resource allocation even when the radio terminal itself does not have a function corresponding to the notification. This allows the wireless base station to control the transmission rate on behalf of the terminal. In addition, when a notification that prompts an increase in the transmission rate is sent from the network when congestion has ended, for example, by reallocation of radio resources, control is performed to efficiently allocate radio resources while improving communication quality. It is possible to do.

According to the fifth aspect of the present invention, when the radio resources which can be allocated increase or decrease after the radio resources are once allocated to the radio terminals under the control of the radio base station, the radio resources are changed according to the increase or decrease of the radio resources. Service attributes of a connection already assigned to
Since the radio resource allocation control is performed again based on the original report parameters, it is possible to appropriately allocate the radio resources, and therefore, it is possible to provide a connection suitable for the medium.

According to the present invention, when the radio base station communicates with the radio terminal, the radio base station transmits, to the radio base station, information for requesting permission or restriction of transmission of data generated based on allocatable radio resources. The terminal notifies the terminal, and the wireless terminal sends or regulates information based on the notification. Therefore, even during communication, it is possible to respond to the connection addition request / bandwidth change request, and at the same time, to the requested connection / bandwidth. Since radio resource allocation control is performed again based on the service attribute of the connection to be changed,
Radio resources can be appropriately allocated, and a connection suitable for media can be provided.

According to the ninth aspect of the present invention, when communicating with a wireless terminal, the radio base station determines the number of retransmissions according to the required quality of service, and performs retransmission processing for the number of retransmissions. While the required service quality can be provided, the error recovery capability by retransmission control can be selected, resulting in efficient operation of radio resources.

According to the tenth aspect of the present invention, when a radio base station communicates with a radio terminal, a redundant bit length is determined according to a required service quality, and an error corresponding to the redundant bit length is determined. Since control is performed, the required service quality can be provided, but even if retransmission control is not suitable due to round trip time of information transmission, etc.
An error recovery capability by error correction control can be effectively selected, and as a result, efficient operation of radio resources can be performed.

Further, according to the present invention, since the radio base station introduces a report parameter indicating traffic characteristics as a service attribute of a connection allocated when communicating with a radio terminal, the connection setting is not fixed. Even if the media attribute or user request changes, a connection can be set in response to the attribute or request, and a user-friendly and advanced communication environment can be realized.

Further, according to the present invention, the network resource management cell (R) in the ABR service class in the ATM system is used.
Wireless resources can be reallocated according to the M cell), and efficient operation of the wireless resources becomes possible.

Furthermore, according to the present invention, the UB is transmitted while avoiding the influence on the communication to which the radio resource has already been allocated.
It is possible to appropriately limit the code resources allocated to the R communication, and it is possible to perform efficient radio resource allocation.

Also, according to the present invention, the required BER
, Error recovery capability by retransmission control or error correction control can be selected, and as a result, efficient operation of radio resources becomes possible.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a wireless communication system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a configuration of a resource allocation control unit according to one embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a configuration of a code assignment management table according to an embodiment of the present invention.

FIG. 4 is a conceptual diagram showing a configuration of a code-band correspondence table according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of a service attribute-based code assignment rule table according to an embodiment of the present invention.

FIG. 6 is a conceptual diagram showing a configuration of a wireless communication system according to another embodiment of the present invention.

FIG. 7 is a conceptual diagram showing a configuration of a retransmission control unit according to another embodiment of the present invention.

FIG. 8 shows quality of service according to another embodiment of the present invention.
It is a figure showing an example of a retransmission number correspondence table.

FIG. 9 is a diagram illustrating an example of a service quality-error control code length correspondence table according to yet another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ATM network 2 wireless base station 3 resource allocation control means 4 wireless terminal 5 wired terminal 6 retransmission control means 7 service quality-retransmission number correspondence table 8 retransmission processing unit 21 wireless base station 22 wireless base station 31 resource allocation control means 32 resource allocation Control means 41 Wireless terminal 42 Wireless terminal 61 Retransmission control means 62 Retransmission control means 310 Code allocation management table 311 Code number-band correspondence table 312 Code allocation rule table by service attribute

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Iguchi 1 Tokoba, Komukai Toshiba-cho, Saisaki-ku, Kawasaki-shi, Kanagawa Inside the Toshiba R & D Center

Claims (10)

[Claims] 1. A communication device for communicating with a wireless terminal via a wireless transmission path, wherein, when allocating a communication connection for communication with the wireless terminal, the communication device uses, for each communication connection used by the wireless terminal, A communication apparatus, comprising: means for allocating a radio resource based on a service attribute of a communication connection and an allocatable radio resource. 2. A communication device for performing communication with a wireless terminal via a wireless transmission path, wherein a service attribute of the additional connection and a service attribute of the additional connection are provided in response to an additional request for a communication connection made from the wireless terminal using the transmission path. A communication device comprising: means for allocating wireless resources based on allocable wireless resources. 3. A communication device for performing communication with a wireless terminal via a wireless transmission path, wherein the communication apparatus receives a request to change a bandwidth of a connection in use using the transmission path from the wireless terminal. A communication device, comprising: means for allocating wireless resources based on service attributes and allocatable wireless resources. 4. A communication device connected to a network and communicating with a wireless terminal via a wireless transmission path, wherein the communication device receives at least congestion notification information or information for performing information loss for a specific communication connection from the network. In this case, the communication device comprises means for changing the assignment of the radio resource to the communication connection. 5. A communication device for communicating with a wireless terminal via a wireless transmission path, wherein when a wireless resource allocated to a communication connection used by the wireless terminal increases or decreases, a service attribute of the communication connection is changed. A communication device comprising means for allocating a radio resource again according to 6. The communication device according to claim 1, wherein the radio resource uses a code division multiple access method using a spreading code. 7. The communication device according to claim 1, wherein the radio resource uses a time division multiple access method using a time division slot. 8. A communication system having a wireless terminal and a wireless base station communicating with the wireless terminal via a wireless transmission path, wherein the wireless base station communicates with the wireless terminal.
Generated based on assignable radio resources, has means for notifying the radio terminal of information requesting permission or regulation of data transmission, the radio terminal, based on the notification received from the radio base station A communication system comprising means for transmitting or regulating information. 9. A communication system comprising a wireless terminal and a wireless base station communicating with the wireless terminal via a wireless transmission path, wherein the wireless base station is provided for each communication connection used by the wireless terminal. A communication system comprising: means for setting the number of retransmission controls based on a service attribute; and wherein the wireless terminal includes means for setting the number of retransmission controls based on a service attribute for each communication connection to be used. . 10. A communication system comprising: a wireless terminal; and a wireless base station that communicates with the wireless terminal via a wireless transmission path, wherein the wireless base station is provided for each communication connection used by the wireless terminal. The wireless terminal has means for setting a code length of an error correction code based on a service attribute, and the wireless terminal has means for setting a code length of the error correction code based on a service attribute for each communication connection to be used. Communication system.