JP3902197B2 - Wireless terminal - Google Patents

Description

  The present invention relates to a radio terminal used in a code division multiple access (CDMA) communication system.

  There is a next-generation mobile communication system as a communication system capable of increasing user capacity and improving communication quality. In this next-generation mobile communication system, a code division multiple access (Code Division Multiple Access) is used as a radio transmission method. (Hereinafter abbreviated as CDMA).

  In this CDMA system, a specific code is assigned to each radio channel, and a modulated wave having the same carrier frequency is spread by the code and transmitted. On the receiving side, code synchronization is performed to identify a desired radio channel. This is the multiple access method.

  This CDMA method is different from the method adopted in PHS, that is, time division multiple access (hereinafter referred to as TDMA), in which a code for a radio base station to identify a radio terminal is determined. As long as the wireless terminal wants to access, there is an advantage that it can always access and communicate with the wireless base station, that is, it can communicate directly for each call, and it also has an advantage of excellent secrecy and interference resistance.

  As a form of realization of the wireless communication system using this CDMA system, for example, a form as shown in FIG.

  That is, this is a case where a large number of wireless terminals such as mobile terminals MS1, MS4 and fixed terminals MS2, MS3 exist within a service area managed by one wireless base station BS. The radio terminals called mobile terminals MS1 and MS4 are usually portable radio telephones that are carried around mainly by humans, and the fixed terminals MS2 and MS3 are those in which a radio adapter for data communication is attached to a personal computer. In many cases, data communication is mainly performed. A wireless telephone is generally a communication mode with call setting, that is, connection-oriented communication (CO type communication), and a personal computer is a communication mode without the above-mentioned CO type communication or call setting, connectionless type communication (CL type communication). ) Is also possible, and in this case, different communication qualities are mixed. When a plurality of wireless terminals performing multimedia communication in which different communication qualities such as CO type communication and CL type communication are mixed are accommodated in one wireless base station as shown in FIG. Even if all communication channels (codes) are assigned, if the number of code multiplexes increases, all communication quality gradually deteriorates, and if the number of code multiplexes exceeds a certain level, all communication becomes impossible. There is.

  Therefore, in order to accommodate a plurality of wireless terminals performing multimedia communication with different communication qualities in one wireless base station, the number of code multiplexes is adjusted to the limit multiplex number of traffic with the highest communication quality requirement. There is a need.

  However, if this is done, the radio base station side must set a threshold value with a considerable margin in advance, and the user capacity may not increase as expected.

  As described above, the conventional CDMA communication system can efficiently accommodate users when accommodating traffic with uniform communication quality, but in a multimedia communication environment where different communication qualities are mixed, There is a problem that the communication efficiency is reduced in multimedia communication because the number of multiplexing needs to be matched with the limit multiplexing number of traffic with the most demanding communication quality, so that the user capacity does not increase as expected. .

  The present invention has been made to solve such a problem, and one radio base station reliably manages the number of code multiplexes below a threshold value without causing communication failure, and among them, It is an object to provide a wireless terminal that can accommodate as many wireless terminals as possible.

In order to solve the above-described problem, a wireless terminal of the present invention is a wireless terminal that transmits and receives data with a wireless base station by a code division multiple access method , and a common channel that is commonly accessed from one or more wireless terminals, A wireless line having a physical channel divided into dedicated channels for one wireless terminal to access is established, management of the number of code multiplexing that the wireless terminal accesses the dedicated channel, and the wireless terminal accesses the common channel The transmission permission for each service class notified from the wireless base station that generates and notifies information on the transmission permission probability for each service class of the transmission information of the wireless terminal that wants to start communication means for receiving information of the probability, accession to the radio base station based on the information of the transmission permission probability for each service class are received It is characterized by comprising a means for scan.

A communication system is a CDMA communication system having at least one wireless terminal and a wireless base station that transmits and receives data to and from the wireless terminal by a code division multiple access method, and is transmitted and received between the wireless terminal and the wireless base station. The number of code multiplexes is divided and managed in terms of time or frequency according to the data communication quality.
In a CDMA communication system having at least one wireless terminal and a wireless base station that transmits and receives data to and from the wireless terminal by a code division multiple access method, a physical channel of a wireless line for transmitting and receiving the data Is divided into a common channel that is commonly accessed from the one or more wireless terminals and an individual channel that is dedicatedly accessed by one wireless terminal, and management of the number of code multiplexes that are accessed by the individual channel; Management of the number of multiplexed codes accessed to the common channel is performed separately.
The radio base station is a radio base station that transmits / receives data to / from one or more radio terminals by a code division multiple access method, and a common channel that is commonly accessed from the one or more radio terminals, and one radio terminal A radio channel having a physical channel divided into dedicated channels to be accessed exclusively is provided, management of the number of code multiplexes for the wireless terminal to access the dedicated channel, and the number of code multiplexes for the wireless terminal to access the common channel Perform management separately.

  In the case of the present invention, since the radio terminal accesses the radio base station based on the transmission permission probability information for each service class received from the radio base station, one radio base station cannot communicate the code multiplexing number. It is possible to reliably manage the threshold value below the threshold value and accommodate as many wireless terminals as possible.

In addition, the CDMA communication system maintains the desired communication quality by dividing and managing the code multiplexing number according to the communication quality of data transmitted and received between the wireless terminal and the wireless base station. However, efficient operation of the system can be realized while maintaining high throughput.
Furthermore, by managing separately the code multiplexing number of the individual channel and the code multiplexing number of the common channel on the system side, it is possible to efficiently perform multimedia communication with different communication quality in wireless communication by the CDMA method. It can be carried out.
In addition, the radio base station separately performs management of the number of code multiplexes for the wireless terminal to access the individual channel and management of the number of code multiplexes for the wireless terminal to access the common channel. Thus, multimedia communication with different communication quality can be performed efficiently.

  As described above, according to the present invention, one radio base station reliably manages the number of code multiplexes below a threshold value without causing communication failure, and as many radio terminals as possible among them. Can be accommodated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a CDMA communication system according to a first embodiment of the present invention.

  As shown in FIG. 1, the CDMA communication system according to the first embodiment includes at least one radio terminal 1, 2 (hereinafter referred to as MS1, 2) and a radio base station 3 (hereinafter referred to as BS3). It has been done. The BS 3 and the MSs 1 and 2 existing in the service area perform data transmission / reception via a code division multiple access radio channel (hereinafter referred to as a CDMA radio channel).

  MS1 and MS2 are terminals that transmit and receive data using a code channel via BS3 and a CDMA wireless line. These MSs 1 and 2 are terminals capable of at least connectionless communication such as IP packets (hereinafter referred to as CL communication) and connection oriented communication such as voice data (hereinafter referred to as CO communication). .

  The BS 3 is an apparatus that accommodates at least one MS 1 and 2 and transmits / receives data using a code channel via a CDMA radio line. Between the BS 3 and the MSs 1 and 2, CL-type communication such as IP packets is performed and CO-type communication such as voice is also performed.

  The radio interface between the BS 3 and the MSs 1 and 2 is shown in FIGS. 3 to 6 in which the logical channel as shown in FIG. 2 and each code are divided in time into the number of communication qualities (number of different service classes). Such physical channels are defined.

  The logical channel shown in FIG. 2 includes a control channel (CCH: Control Channel) used for transmitting / receiving control information and a communication channel (TCH: Traffic Channel) used for transmitting / receiving user information. The TCH is a bidirectional or downlink / uplink unidirectional channel for carrying user information, and is a communication channel (DTCH: Dedicated Traffic) used for communicating real-time user information (centered on CO-type communication data) such as voice. Channel) and a user packet channel (UPCH: User Specific Packet Channel) for transmitting and receiving packet data information in a bidirectional or uplink / downlink unidirectional channel for carrying user information. The packet data information is usually centered on CO-type communication data, but may include data information on CL-type communication, and may include control information defined by the user.

  The CCH is a point-multipoint control channel (CCCH) that carries connectionless messages, and a dedicated control channel (DCCH) that is a point-to-point bidirectional control channel. It is composed of

  CCCH is a channel used to broadcast information to the wireless terminal, and is received before the wireless terminal accesses the network. The network number, the wireless base station number, the sector number, the location registration area number, the number of perch channels, the stop Broadcast channel (BCCH), which is a point-multipoint downlink unidirectional common control channel for acquiring system information such as tree channel number, restriction information, control channel structure information, and extended information elements, and call establishment A random access channel (RACH: Random Access Channel), which is a unidirectional common control channel that carries messages such as requests and responses to inquiries from the network, and messages such as inquiries to radio terminals and radio-related resource allocation ( The packet data information may also be carried). And a general access channel (PCH: Paging Channel) that is a downlink unidirectional common control channel used for wireless terminal simultaneous paging (paging) when a wireless terminal is connected. ing.

  The DCCH is assigned together with a dedicated control channel (SDCCH: Stand alone Dedicated Control Channel), which is a point-to-point dedicated control channel used for TCH allocation, etc. (along with UPCH if necessary) Point-to-point bi-directional dedicated control channel (Associated Control Channel).

  The physical channel shown in FIGS. 3 and 4 has a configuration of a downlink common control channel (BCCH, PCH, FACH). In the example of FIG. 3, one superframe is composed of a plurality of radio frames (frame # 1 to frame # (L + M + N)). One radio frame includes a plurality of time slots # 1 to # (l + m + n). In this example, BCCH, PCH, and FACH are multiplexed (mixed) for each time slot.

  In the example of FIG. 4, one super frame is composed of a plurality of radio frames (frame # 1 to frame # (L + M + N)). One radio frame includes a plurality of time slots # 1 to # (l + m + n). In this example, BCCH, PCH, and FACH are multiplexed (mixed) for each radio frame, and BCCH, PCH, and FACH are multiplexed (mixed) for each time slot.

  In addition to the above, the physical channel may have a configuration in which BCCH, PCH, and FACH are multiplexed (mixed) at the time slot level or the radio frame level, for example. Although not shown, this physical channel may have a configuration in which BCCH, PCH, and FACH are multiplexed at a superframe level (a configuration in which BCCH, PCH, and FACH can always be transmitted).

  The physical channels shown in FIGS. 5 and 6 are divided into three different service classes such as service class 1, service class 2 and service class 3 in terms of time or carrier (frequency). Service class 1 is a service class for high reliability / high communication quality assurance type CL communication such as communication of control information by random access. Service class 2 is a service class for performing CO-type communication for guaranteeing communication quality such as delay such as voice communication. Service class 3 is a service class for performing Best Effort type CL communication such as packet communication.

  FIG. 5 shows an example in which the physical channel is divided into a plurality of service classes at the time slot level, and FIG. 6 shows an example in which the physical channel is divided into a plurality of service classes at the radio frame level. Each RACH is mapped to service class 1. SDCCH, ACCH, DTCH, and some UPCHs are mapped to service class 2. A part of UPCH is mapped to service class 3.

  In this CDMA communication system, when MS 1 and 2 perform CO-type communication such as voice with BS 3, BS 3 assigns a code to MS 1 and 2 individually, and each MS 1 and 2 uses a code assigned from BS 3. Send data.

  In BS3, the multiplex number is managed separately for each of the service classes 1, 2, and 3, and when the MS1 and 2 perform CL-type communication such as a packet, the MS1 and 2 do not transmit an unlimited number of packets. As described above, the transmission permission probability information for each service class 1, 2, 3 is notified from the BS 3 to the MS 1, 2.

  The MSs 1 and 2 transmit data using codes (codes) to which the MSs 1 and 2 are commonly assigned based on the transmission permission probability information broadcast from the BS 3.

  On the other hand, for example, when performing CL type communication, the MSs 1 and 2 transmit packets based on the transmission permission probability information for each of the service classes 1, 2, and 3.

  Thereby, on the BS 3 side, the number of multiplexing for each service class 1, 2, 3 can be managed so as to be kept below a set threshold value.

  Hereinafter, the operation when performing voice communication such as telephone and data communication such as packet communication and the multiplexing management method at that time will be described more specifically. Note that the operation when performing packet communication includes the operation of communication of control information by random access.

  The MSs 1 and 2 first receive system-related information such as a channel structure periodically broadcast from the BS 3 using the BCCH, and operate based on the received broadcast information.

  Here, first, an operation during voice transmission will be described as an operation during voice communication.

  When the MS 1 and 2 perform voice transmission, the service class 2 dedicated channel (DTCH) is allocated from the BS 3 by performing call setting using the service class 1 RACH and FACH and the service class 2 SDCCH. Data communication between each other.

  At this time, when the MSs 1 and 2 perform random access using the RACH, packets are transmitted based on the transmission permission probability information of the service class 1 periodically broadcast from the BS 3 using BCCH or the like. Thereby, in BS3, the multiplexing number can be managed so as to satisfy the communication quality of service class 1.

  On the other hand, when MS1 and MS2 receive voice, if there is a call from BS3 to MS1 and MS2 based on PCH, MS1 and MS2 make an incoming call response to BS3 using the service class 1 RACH. Then, the dedicated channel (DTCH) of the service class 2 is assigned by the BS 3 using the SDCCH or the like of the service class 2, and data communication can be performed between them.

  At this time, when the MS 1 and 2 perform random access using the RACH, the packet is transmitted based on the transmission permission probability information of the service class 1 as in the case of voice transmission. Next, an operation during packet transmission will be described as an operation during packet communication. When the MSs 1 and 2 perform packet transmission, the service class 2 or the service class 3 UPCH is selected according to the communication quality required for packet communication, and the selected service class is selected in advance. A packet is selected by randomly selecting a code from the assigned code group.

  At this time, when MS 1 and 2 perform random access using UPCH, MS 1 and 2 are based on the transmission permission probability information of service class 2 or service class 3 periodically broadcast from BS 3 using BCCH or the like. Send the packet.

  Here, the service class 2 UPCH performs call setup using the service class 1 RACH and FACH and, if necessary, the service class 2 SDCCH as in the case of voice transmission. Then, the UPCH is assigned by the BS 3 as an individual channel of the service class 2, and communication becomes possible.

  On the other hand, when MS1 and MS2 receive a packet, when there is a call from BS3 to MS1 and MS2 based on PCH, MS1 and MS2 respond to the incoming call with the service class 1 RACH. Then, BS 3 is assigned a service class 2 UPCH (dedicated channel) or a service class 3 UPCH (shared channel) using FACH. As a result, the MSs 1 and 2 receive a packet based on the assigned UPCH.

  Here, UPCH allocation at the time of packet reception may be performed using RACH and FACH as described above, or UPCH (code) for packet reception may be allocated by PCH.

  By adopting such a configuration, there is an advantage that random access necessary for channel allocation for packet reception can be reduced.

  Also, instead of calling by PCH, a call channel dedicated for packet communication is defined as one of UPCHs, and UPCH for calling or / and receiving packets is assigned using UPCH for calling during packet communication. Also good.

  In the following, a method for managing the number of code multiplexes when RACH and UPCH at the time of CL-type communication packet transmission are mixed in an upstream communication packet of CO-type communication will be described.

  From BS3, transmission permission probability information for each service class is periodically notified to MS1 and MS2.

  When there is CL-type communication information to be transmitted, the MSs 1 and 2 transmit a packet based on the transmission permission probability PAi of the service class i of the information to be transmitted received at that time.

  In BS3, the transmission permission probability for each service class i is calculated by the next notification timing (during Δt) based on the following calculation formula, and the updated transmission permission probability is assigned to MS1 and MS2. Operates to inform.

Transmission permission probability PBi = calculated value of transmission permission probability PAi> = 1 → 1
Calculated value of transmission permission probability PAi <1 → calculated value ○ Calculated value of transmission permission probability PAi = number of empty channels by service class NEi
/ Estimated number of calls NDi by service class
(Predicted number of new code multiplex numbers)
● Number of free channels NEi by service class
= Multiple threshold code THi by service class
-Code multiplexing number Ci by service class
-Γ (margin)
NEi = THi−Ci (t + Δt) −γ
★ Cable multiplexing number Ci (t + Δt) by service class
= Number of multiplexed codes Ci (t) for each service class
+ Number of new calling codes by service class CAi (Δt)
-Number of new call loads CBi (Δt) by service class
Ci (t + Δt) = Ci (t) + CAi (Δt) −CBi (Δt)
● Estimated number of calls NDi by service class
= Number of non-communication terminals in base station NB × number of codes Mi
× Call rate QBi by service class
× Packet generation rate (occupation rate) α
+ Number of terminals in communication in base station NA x number of codes Mi
× Call rate QCi by service class
× Packet generation rate (occupation rate)
NDi = NB × Mi × QBi × α + NA × Mi × QCi × α
★ Number of terminals communicating in base station NA
= Sum of the number of terminals communicating in the base station by service class ΣNAiNA
= ΣNAi (t + Δt)
☆ In-station communication terminal NAi (t + Δt) by service class
= Number of terminals in communication in base station by service class NAi (t)
+ Number of calling terminals MAi (Δt) by service class
-Number of terminal calls by service class MBi (Δt)
NAi (t + Δt) = NAi (t) + MAi (Δt) −MBi (Δt)
★ Number of uncommitted terminals in base station NB
= Total number of terminals in base station N-Number of terminals in communication in base station NA
NB = N-NA
In this way, the transmission permission probability for each service class i in BS3 is recalculated by the next timing, and the updated transmission permission probability is notified to MS1 and MS2.

  That is, the physical channel configuration of the radio interface between MS1, 2 and BS3 is transmitted and received between MS1,2 and BS3 in a configuration in which the physical channel configuration is divided into a plurality of service classes in time slot level or radio frame level. In this case, since it is mapped to a desired service class according to the communication quality, if the MS 1 and 2 operate based on the transmission permission probability information for each service class broadcast from the BS 3, the amount of data transmitted and received at this time The (number of multiplexed codes) can be managed on the BS 3 side.

  As described above, according to the CDMA communication system of the first embodiment, the code multiplexing number is divided and managed in accordance with the communication quality of data transmitted and received between the MS 1 and 2 and the BS 3, so that the channel with the strictest required quality is provided. Thus, the number of multiplexing is not limited. This is because the number of code multiplexes for service class channels with a low requirement quality is increased compared to the number of code multiplexes for service class channels with a strict requirement quality. As a result, the number of terminals accommodated in one BS 3 can be increased. In particular, if the number of multiplexed user packets for the best effort CL type communication such as packet communication is increased, the terminals can be accommodated efficiently.

  In addition, by dividing and managing the number of code multiplexes according to the data communication quality, when access is concentrated on the shared channel used to transfer user packets of Best Effort CL type communication such as packet communication However, it is possible to maintain the communication quality of the individual channel mainly used for the control shared channel and the CO-type communication at a desired value or higher. As a result, a CDMA communication system with high channel utilization efficiency can be realized.

  Next, a second embodiment of the CDMA communication system according to the present invention will be described with reference to FIG. FIG. 7 is a diagram showing the configuration of the second embodiment of the CDMA communication system according to the present invention.

  As shown in FIG. 7, this CDMA communication system includes radio terminals 10-12 (hereinafter referred to as MS10-12), radio base stations 20-2N, 30-3N (hereinafter referred to as BS20-2N, BS30-3N), Radio base station control stations 40 and 41 (hereinafter referred to as BSCs 40 and 41), mobile switching centers 50 and 51 (hereinafter referred to as MSCs 50 and 51), a backbone network 60, a fixed terminal 70, a telephone terminal 71, and the like.

  A fixed terminal 70, MSCs 50, 51, and the like are connected to the backbone network 60. A BSC 40 is connected to the MSC 50. BSs 20 to 2N are connected to the BSC 40. The BSC 41 is connected to the MSC 51. BSs 30 to 3N are connected to the BSC 41. Each BS 20-2N, 30-3N establishes a radio link with the MSs 10-12 existing in the service area of the own station, and transmits and receives data between the fixed terminal 70 and the MSs 10-12. In this case, a logical channel as shown in FIG. 3 described above is defined in the interface of the wireless line. The MSs 10 to 12 are terminals that transmit and receive data by establishing a wireless line with any of the BSs 20 to 2N and 30 to 3N. These MSs 10 to 12 are terminals capable of at least CL-type communication such as IP packets and CO-type communication such as voice.

  For example, as shown in FIG. 8, the BS 20 transmits and receives RF signals using the plurality of antennas 100 and these antennas 100, and separates and multiplexes RF transmission signals and RF reception signals and connects to the plurality of antennas 100. The transmission / reception amplification unit (AMP) 101 and the RF reception signal output from the reception amplifier of the transmission / reception amplification unit (AMP) 101 are detected and further A / D converted to the baseband signal processing unit (BB) 103. A radio unit (TR) 102 for transmitting and D / A converting the transmission signal baseband spread by the baseband signal processing unit (BB) 103 and converting it to an RF transmission signal by orthogonal modulation, and error correction of transmission data Encoding, framing, data modulation, spread modulation and received signal despreading, chip synchronization, error decoding, data demultiplexing, inter-sector handover Baseband signal processing unit 103 that performs baseband signal processing such as maximum ratio synthesis at the time, and base station control unit that performs transmission / reception of control signals to / from BSC 40 and MSC 50, and performs radio channel management, radio channel setting, release, etc. (Communication interface between BTC-CNT104 and external BSC40, including asynchronous transfer mode processing function (ATM processing function), ATM Adaptation Layer type2 function (AAL2 function), ATM Adaptation Layer type5 function (AAL5 function), etc. And a transmission path interface unit (BS-IF) 105 that generates its own operation clock based on information obtained from the transmission path, and a transmission amplifier that amplifies a transmission RF signal. A receiving amplifier that amplifies the received RF signal, and an antenna that separates or multiplexes the RF transmission signal and the RF reception signal 00 function to connect is provided in. In addition, BS other than the BS20, is the same configuration, such as for example BS2N and BS30～3N.

  The processing shown in FIG. 9 is performed inside each BS 20-2N and 30-3N. Note that the process differs between when data is received and when data is transmitted.

  For example, when the BS 20 or the like receives data of a plurality of time slots # 1 to #n on the reception physical channel, the data of each time slot is assembled to generate a radio unit. Subsequently, bit deinterleaving is performed on the radio unit, Viterbi decoding is performed to generate a radio packet including a radio packet header, data, CRC, TA, and the like, and error correction is performed by CRC. Thereafter, the data portion is subjected to inner coding and divided into inner coding units to obtain variable length packets including data, PAD, trailer, and the like.

  On the other hand, when the BS 20 transmits data, the data in the variable-length packet is combined with the inner coding unit to generate a radio packet including a radio packet header, data, CRC, TA, and the like.

  Subsequently, the wireless packet is convolutionally encoded and bit-interleaved to generate a wireless unit.

  Thereafter, the wireless unit is disassembled into a plurality of time slots, and the data is transmitted in the plurality of time slots # 1 to #n of the transmission physical channel.

  As shown in FIG. 10, the BSC 40 or the like is a communication interface with external BSs 20 to 2n, and includes a transmission path interface unit (BSC-IF) 201 having an ATM processing function, an AAL2 function, an AAL5 function, and the like. A function of selectively combining user data and control signals from BSs 20 to 2n and a function of distributing user data and control signals to a plurality of BSs 20 to 2n. A diversity handover processing unit (DHO) 202 that performs diversity handover processing, a codec unit (CODEC) 203 that performs encoding / decoding and conversion of voice data, mainly a radio channel control, a control function for DHO 202, and a control for CODEC 203 Base station control station control unit (BSC-C T) 204 and a radio base control station switch unit that performs switching of user information and control information transmitted / received between the above-described units, that is, BSC-IF 201, DHO 202, CODEC 203, and BSC-CNT 204, in accordance with instructions from BSC-CNT 204 (BSC-SW) 205. The configuration of the BSC 41 is the same as that of the BSC 40 except for the connection destination.

  As shown in FIG. 11, the MSC 50 has a codec unit (CODEC) 301 that performs encoding / decoding of audio data and conversion thereof, and a signal processing function of user data, and includes packet processing, modem retransmission processing, etc. Adapter unit (ADP) 302 that performs a conversion function, an external interface unit (EX-IF) 303 that has a function of converting a voice analog signal and a PCM signal and has an interface function with the backbone network 60, an exchange control function, and call control The mobile switching center control unit (MSC one CNT) 304 having a function and a control function for the ADP 302 and the function of switching between the ADP 302 and the EX-IF 303 in accordance with a command from the MSC-CNT 304, user data and control Mobile switching center switch unit (MSC-SW) 3 for switching information And a 5. The configuration of the MSC 51 is the same as that of the MSC 50 except for the connection destination.

  The backbone network 60 is an ATM exchange network, ISDN, Internet, or the like having switching and routing functions for mutually connecting MSCs 50 and 51, a fixed terminal 70, a telephone terminal 71 and the like to realize communication such as data and voice.

  The fixed terminal 70 is a terminal connected to the backbone network 60 and capable of performing data communication with at least the MSs 10 to 12 using IP packets.

  The IP packet transmission between the fixed terminal 70 and the MSs 10 to 12 is performed via the MSCs 50 and 51, the BSCs 40 and 41, and the BSs 20 to 2N and 30 to 3N. Even if it moves within the area, it is possible to continue communication.

  The telephone terminal 71 is connected to the backbone network 71 and is a terminal that can perform voice communication with at least the MSs 10 to 12. The voice transmission between the telephone terminal 71 and the MSs 10 to 12 is performed via the MSCs 50 and 51, the BSCs 40 and 41, and the BSs 20 to 2N and 30 to 3N. Communication can be continued even when moving within a service area of 30 to 3N.

  In the CDMA communication system of the second embodiment, the physical channel of the radio interface is configured as shown in FIGS. 12 and 13, and is mapped to the logical channel as follows.

  That is, the physical channel shown in FIG. 12 includes a plurality of continuous superframes. Each super frame is composed of a plurality of radio frames. Each radio frame is composed of a plurality of time slots.

  The configuration of each radio frame is such that there is at least one of the three slots of slot configuration 1, slot configuration 2, and slot configuration 3.

  As the slot configuration 1, the slot configuration in the radio frame is temporally divided into m dedicated channel slots and n shared channel slots.

  As the slot configuration 2, all slot configurations in the radio frame are defined as dedicated channel slots (m + n).

  As the slot configuration 3, all slot configurations in the radio frame are defined as shared channel slots (m + n).

  BCCH, FACH, PCH, and RACH are mapped to slot configuration 3. SDCCH, ACCH, DTCH, and some UPCHs are mapped to slot configuration 2. A part of UPCH is mapped to slot configuration 1. Furthermore, BCCH, FACH, PCH, and RACH are mapped to service class 1. (SDCCH, ACCH, DTCH) Some UPCHs are mapped to service class 2. A part of UPCFI is mapped to service class 3.

  Further, the physical channel shown in FIG. 13 is composed of a plurality of continuous superframes. Each super frame is composed of a plurality of radio frames. Each super frame has a configuration in which there are both or one of the two frames, frame configuration 1 and frame configuration 2. Frame configuration 1 is a frame in which p dedicated channel frames and q shared channel frames are separately defined, that is, temporally divided. Frame configuration 2 is a frame in which either a dedicated channel frame or a shared channel frame is defined for each radio frame, and each frame is arbitrarily divided and mixed.

  That is, each super frame has a physical channel configuration in which a dedicated channel frame and a shared channel frame are mixed, in which one or both of the frame configuration 1 and the frame configuration 2 are provided.

  A part of BCCH, FACH, PCH, RACH, and UPCH is mapped to a frame for shared channel of frame configuration 1 or frame configuration 2.

  SDCCH, ACCH, DTCH, and some UPCHs are mapped to dedicated channel frames of frame configuration 1 or frame configuration 2.

  BCCH, FACH, PCH, and RACH are mapped to service class 1. SDCCH, ACCH, DTCH, and some UPCHs are mapped to service class 2. A part of UPCH is mapped to service class 3.

  Here, more specific mapping between physical channels and logical channels will be described with reference to FIGS.

  As shown in FIG. 14, the mapping between the uplink physical channel and the logical channel is as follows. In the radio interfaces of the BSs 20 to 2N and 30 to 3N, the frame numbers 1 to 8 of the code # A1 of the carrier 2a allocated to the RACH are All are common control channels. Frame numbers 1 to 8 of codes # B1 to Bn of the carrier 2a assigned to the SDCCH are all dedicated control channels. The frame numbers 1 to 8 of the codes # 51 to 5m of the carrier 2b and the frame numbers 1 to 4 of the codes # 61 to 6m of the carrier 2c assigned to the DTCH are all dedicated communication channels for CO type communication. Frame numbers 1-8 of codes # 51-5m of carrier 2b allocated to UPCH are all dedicated communication channels for CL communication, and frame numbers 5-8 of codes # 61-6m of carrier 2c are all common for CL communication. It is a communication channel.

  Further, as shown in FIG. 15, the mapping between the downlink physical channel and the logical channel is performed in the frame numbers 1 to 11 of the code # 11 of the carrier 1a allocated to the BCCH in the radio interfaces of the BSs 20 to 2N and 30 to 3N. 8 is a common control channel. Further, the frame numbers 1 to 8 of code # 21 of the carrier 1a assigned to the PCH are all common control channels. Frame numbers 1 to 8 of code # 31 of carrier 1a assigned to FACH are all common control channels. Frame numbers 1 to 8 of codes 41 to 4m of the carrier 1a assigned to the SDCCH are all dedicated control channels. The frame numbers 1 to 8 of the codes # 41 to 4m of the carrier 1b assigned to the DTCH are all the individual communication channels of the CO type communication, and the frame numbers 1 to 4 of the codes # 51 to 5m of the carrier 1c. Frame numbers 1-8 of codes # 41-4m of carrier 1b assigned to UPCH are all dedicated communication channels for CL communication, and frame numbers 5-8 of codes # 51-5m of carrier 1c are all CL type. A common communication channel for communication.

  The example of the physical channel shown in FIGS. 12 and 13 has a configuration in which the individual channel and the common channel are divided in terms of time or frequency at the slot level or the frame level, and the first embodiment described above. The same effect as in the first embodiment can be obtained by separately managing the number of code multiplexes according to the communication quality of data transmitted / received between the MS 10-12 and the BS 20-2N, 30-3N by the same method. be able to.

  In the first and second embodiments, the code multiplexing number is completely divided in time or / and frequency according to the communication quality of data transmitted / received between the MS and the BS (for each service class). Although the configuration of the physical channel is shown, it need not be completely separated.

  For example, it may be configured such that it overlaps with different service classes in terms of time or carrier. In this case, by managing the number of code multiplexes for each service class, the same effects as those of the above embodiments can be obtained. In this case, the physical channel of the service class is used in combination with interleaving as shown in FIG. 7, so that the communication quality that is non-uniform in time within the same service class is uniform. Can be

  In addition, for example, when allocating channels, channel allocation is performed in order from the lowest multiplexed frames and slots, and slots and frames in which common channels and dedicated channels overlap in time are allocated to dedicated channels as much as possible. May be used for assignment when the communication quality may be slightly degraded when the channel is insufficient such as during handoff. Furthermore, it is conceivable to separately manage the number of multiplexed uplink / downlink channels.

As described above, a code division multiple access communication system can be achieved by managing the number of code multiplexes in time or frequency according to the communication quality of data transmitted and received between the wireless terminal and the wireless base station. While maintaining the desired communication quality, it is possible to maintain a high throughput and realize an efficient operation of the system.
In addition, by separately managing the number of code multiplexes accessed to the individual channel and the number of code multiplexes accessed to the common channel, the communication quality differs in performing wireless communication by the code division multiple access method. Multimedia communication can be performed efficiently.

The figure which shows the structure of 1st Embodiment of the CDMA communication system of this invention. 1 is a diagram showing a logical channel configuration of a radio line in a CDMA communication system according to a first embodiment. The figure which shows the 1st structure of the physical channel of the radio | wireless line of the CDMA communication system of 1st Embodiment. The figure which shows the 2nd structure of the physical channel of the radio | wireless line of the CDMA communication system of 1st Embodiment. The figure which shows the example by which the service class is divided | segmented at the time slot level. The figure which shows the example by which the service class is divided | segmented by the radio | wireless frame level. The figure which shows the structure of 2nd Embodiment of the CDMA communication system of this invention. The figure which shows the structure of BS of the CDMA communication system of 2nd Embodiment. The figure which shows the internal process of BS of the CDMA communication system of 2nd Embodiment. The figure which shows the structure of BSC of the CDMA communication system of 2nd Embodiment. The figure which shows the structure of MSC of the CDMA communication system of 2nd Embodiment. The figure which shows the physical channel defined for every time slot in the CDMA communication system of 2nd Embodiment. The figure which shows the physical channel defined for every flame | frame in the CDMA communication system of 2nd Embodiment. The figure which shows the example of a mapping of the uplink physical channel and logical channel of the CDMA communication system of 2nd Embodiment. The figure which shows the example of a mapping of the downlink physical channel and logical channel of the CDMA communication system of 2nd Embodiment. The figure which shows a mode that the uplink transmission packet concentrates on BS in the conventional CDMA communication system. The figure which shows the mode of the management of the multiplexing number in the conventional CDMA communication system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Wireless terminal (MS), 3 ... Wireless base station (BS), 10-12 ... Wireless terminal (MS), 20-2N, 30-3N ... Wireless base station (BS), 40, 41 ... Wireless base Station control station (BSC), 50, 51 ... Mobile switching center (MSC), 60 ... Backbone network, 70 ... Fixed terminal, 71 ... Telephone terminal.

Claims (1)

In a wireless terminal that transmits and receives data using a code division multiple access method with a wireless base station,
A wireless channel having a physical channel divided into a common channel that is commonly accessed by one or more wireless terminals and a dedicated channel that is dedicatedly accessed by one wireless terminal is provided, and the wireless terminal accesses the dedicated channel. Separately manages the number of code multiplexes and the number of code multiplexes that the wireless terminal accesses to the common channel, and generates transmission permission probability information for each service class of transmission information of the wireless terminal that wants to start communication. Means for receiving transmission permission probability information for each service class broadcast from the radio base station to broadcast;
A wireless terminal comprising: means for accessing the wireless base station based on the received transmission permission probability information for each service class.

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