JPH1032579A - Private radio transmission method for radio atm-lan and system therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system in which a master set efficiently and dynamically assigns a resource with respect to a service request of a wide range over a speed from a low to a high speed from a node in the private radio transmission system in a radio ATM-LAN of the code division multiple access(CDMA)/FDD access system. SOLUTION: Each of master sets 100-102 being a radio base station is provided with an equipment that uses a combination of a plurality of spread codes and a plurality of tip rates in the CDMA so as to conduct resource management in its own service area, radio terminal equipment in the service area or an equipment conducting resource distribution based on combination of a spread code and a tip rate in response to the service request from an ATM terminal equipment at the side of an ATM-LAN 600. When the radio terminal equipment receives designation of a plurality of spread codes and a plurality of tip rates from the master sets 100-102, the radio terminal equipment has a transmitter and a receiver which set a spread code and a tip rate corresponding to the designation to revise the transmission speed optimizingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a local wireless transmission system, and more particularly to a local wireless transmission method and system for dynamically allocating resources in a network in a wireless ATM-LAN.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No. Hei 7-46248 discloses a conventional wireless communication system capable of coping with the movement of a wireless terminal communicating by transmitting and receiving ATM cells and performing ATM meta-signaling via a wireless line. Is disclosed. According to the publication, this system comprises a wireless relay device 701 and first wireless terminals 731 to 73 that perform communication by transmitting and receiving ATM cells to and from the wireless relay device.
3 and a second wireless terminal 734 that communicates with the wireless relay device by transmitting and receiving ATM cells and that communicates with the backbone communication network 705. The wireless relay device 701 has a service area. , A plurality of spot beam areas A1 to A3, antennas 711 to 718 for providing a wireless channel by a wide area beam area A0, transmitters 721 to 724, receivers 725 to 728, and receivers 725 to 728. For switching ATM cells output from the transmitter to desired transmitters 721 to 724
A switching device 729 is provided. The spot beam area is used for high-speed communication such as image communication, and the wireless communication for the wide-area beam area is performed for low-speed communication such as voice communication. Therefore, mobile communication is easily performed and multimedia communication is performed. It is done.

[0003] Further, the above-mentioned invention uses a CD as shown in FIG.
A variable transmission rate is made possible by associating a code resource in a multi-access technique for an MA (Code Division Multi-Access) system with VPI and VCI, which are ATM cell identifiers.

However, this system has the following problems.

[0005] The means using the spot beam system and the wide area beam wireless line complicate the control of both, and the spot beam system causes line-of-sight communication and is limited by the installation conditions between the master station and the wireless terminal. There is also.
In addition, a specific configuration of a variable factor corresponding to a variable factor in CDMA, which is a large factor, is not specified.

Here, in the case of CDMA, a method is generally considered in which one code is assigned and its chip rate is changed according to the transmission rate. For example, when the primary modulation before performing the spread spectrum processing is QPSK (Quadrary Phase Shift Keying) and the spread spectrum rate is 32, voice (32 Kbps), character data (64 Kbps to 128 Kbps), and image (about 2 Mbps) In the above case, the chip rates are 512 Kcps (voice) and 1.024 M
~ 2.048 Mcps (data) and 32 Mcps
s (image), which is a value that can be sufficiently covered by future advances in LSI technology. In contrast, about 6 Mbp
s MPEG2 (moving picture expert group 2) for communication, the chip rate is 96 Mc
ps, which is difficult to realize in terms of power consumption and usable LSI.

[0007]

As described above, the conventional wireless ATM LANs adopt a connectionless architecture based on CSMA, which is carrier sense multiple access, as an access method. For this reason, for real-time services such as audio and video, IEEE 802.11 (TIME
BOUNDEDSERVICE), a mixed system of the polling system and the CSMA system is considered. However, in a conventional wireless LAN, it is not possible to dynamically allocate a transmission band to each terminal in response to a multimedia service request such as voice, data, and image, as in ATM-LAN, and to guarantee communication quality by priority. Have difficulty.

[0008] The wireless communication system disclosed in Japanese Patent Application Laid-Open No. 7-46248 has the following problems.

[0009] The means using the spot beam system and the wide area beam system wireless circuit complicate the control of both, and the spot beam system requires line-of-sight communication, which limits the installation conditions between the master station and the wireless terminal. There are also problems. In addition, a specific configuration of a variable factor corresponding to a variable factor in CDMA, which is a large factor, is not specified.

Here, in the case of CDMA, a method is generally considered in which codes are assigned and the chip rate is changed according to the transmission rate. For example, if the primary modulation before performing the spread spectrum processing is QPSK and the spread spectrum rate is 32, the above-mentioned case is assumed for voice (32 Kbps), character data (64 Kbps to 128 Kbps), and image (about 2 Mbps). Under the conditions, the chip rate is 512 Kcps (voice) 1.02 each
4M to 2.048 Mcps (data) and 32M
cps (image), which is a value that can be sufficiently covered by future advances in LSI technology. In contrast, about 6M
In the case of communication of MPEG2 of bps, the chip rate becomes 96 Mcps, and in terms of power consumption and available LSI
It is difficult to realize in terms of

[0011] It is an object of the present invention to provide a wireless communication system using a CDMA / FDD access method, in which a master unit manages resources in a wireless section in a unified manner using a combination of a spreading code and a plurality of chip rates, and responds to a service request from a wireless node. Thus, a means for dynamically assigning resources corresponds to a variable transmission rate. Furthermore, a wireless ATM-LAN private wireless transmission method and system that enables efficient use of a source by transmitting and receiving a spreading code and a chip rate on a wireless node side in response to a resource assignment from a base unit. To provide.

[0012]

SUMMARY OF THE INVENTION A wireless ATM-L according to the present invention.
A local area wireless transmission method in an AN is a wireless ATM-LAN local area wireless system in which a CDMA / FDD method is adopted as an access method of a wireless node in a service area managed by a base station, which is a base station connected to an ATM-SW. In the transmission method, the master unit classifies resources of a transmission medium in the service area using a combination of at least one spreading code and a chip rate in CDMA, and manages a use state; Call request from a wireless node and ATM-L
Performing a resource allocation to the wireless terminal by a combination of a spreading code and a chip rate in response to a connection request from the ATM terminal on the AN side to the wireless node, wherein the wireless terminal transmits at least Upon receiving designation of one spread code and chip rate, the method includes a step of setting the spread code and chip rate corresponding to the designation.

Further, the private wireless transmission system in the wireless ATM LAN of the present invention employs a CDMA / FDD method as an access method of a wireless node in a service area managed by a base unit which is a base station connected to the ATMSW. Means for performing resource management of transmission media in the service area by using a combination of at least one spreading code and a chip rate in CDMA, Means for allocating resources to the wireless node by a combination of a spreading code and a chip rate in response to a call request from a wireless node in the area and a connection request from the ATM terminal on the ATM-LAN side to the wireless node. And wherein said wireless node communicates with at least one spreading code from said master unit. When a chip rate is specified, a spreading code corresponding to the designation and a transmitting means and a receiving means for setting the chip rate are provided.

As described above, since the present invention transmits and receives resources using a combination of a set of a chip rate and a spreading code, efficient wireless transmission is possible for each of voice, data, image, and image services. It is.

[0015]

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

FIG. 1A is a block diagram of an embodiment of a system to which the wireless ATM-LAN private wireless transmission method of the present invention is applied, and FIG. 1B is a schematic diagram of a transmitting device and a receiving device of a wireless node 1. It is a block diagram. L of this wireless ATM-LAN
The premises wireless transmission system includes base stations 100 and 1 serving as base stations.
01 to 10n and the wireless nodes 201, 202, to 20
m, service areas 400, 401, to 40n of master stations 100, 101, to 10n, a wireless ATM-SW 300 as a mobile switching center of the master station, and ATM nodes 500, 501, to 50p in the ATM-LAN 600. , Consisting of

FIG. 2 shows the correspondence between ATM VPs and VC bandwidth requests in a wireless section according to the present invention.

Table 1 shows one embodiment of the resource management using the spreading code and the chip rate on the master station side according to the present invention.

FIG. 3 shows an example of a configuration of a multi-rate transmitting apparatus using a chip rate and a spreading code set on the transmitting side of a wireless node in the present invention.

Table 2 shows one embodiment of how the chip rate and spreading code set are associated with voice, data, image, and image services in the present invention.

[0021]

[Table 1]

[0022]

[Table 2] FIG. 4 shows an example of the configuration of a multi-rate receiving apparatus on the receiving side of the wireless node according to the present invention.

The transmitter of the wireless node shown in FIG. 3 is a wireless ATM-MAC (media access control) 10
, Serial / parallel converter 20 and primary modulator 3
0, 31, 32, phase shifters 40, 41, 42, chip rate switching unit 60, spreading code generation unit 50, spectrum spreaders 70, 71, 72, addition times 80, D
An A / A converter 91, a radio section 92, and an antenna 93 are provided.

The receiver of the wireless node shown in FIG. 4 includes a wireless ATM-MAC 15 and a parallel / serial converter 25.
, A primary demodulator 35, and phase shifters 45, 46, 47
, A spreading code generator 50 and a chip rate switcher 60
, Despreaders 85, 86, 87 and A / D converter 9
7, a radio unit 96, and an antenna 95.

Next, the operation of this embodiment will be described.

The wireless node 1 can communicate not only with the other wireless nodes 2 and 3 but also with the ATM nodes 500, 501 and 502 in the ATM-LAN. Communication between the wireless nodes is performed via the base unit 100, and the ATM
Communication between nodes 500, 501, and 502 is based on master unit and ATM.
-Via SW. Communication in the wireless section is not connectionless but connection-type. That is, when a transmission request occurs in the wireless node, ATM-based signaling is performed with the master unit, and resources are assigned from the master unit to shift to the communication mode. Wireless nodes 1-3 and A
When performing communication between the TM nodes 500 to 502, the QoS on the ATM-LAN side in the signaling mode.
(Quality of service) parameters of parent device 100
Is converted to the resource assignment of the wireless section. Here, the wireless ATM-LAN is required to be able to handle voice, data, image information such as still images and graphics, and multimedia information such as MPEG1 and MPEG2 image signals. However, since resources in a wireless section are generally limited in a wireless ATM-LAN compared to an ATM-LAN, a means for efficiently assigning limited resources in a wireless section is essential. FIG. 2 and Table 2 show resource assignment means in the present invention.

FIG. 2 shows a CD as an access method according to the present invention.
The configuration of VPI and VC when MA / FDD is adopted is shown. As for correspondence with ATM, VP corresponds to uplink and downlink frequencies, and VC corresponds to the chip rate and the number of spreading codes in CDMA. Each parent device 100, 101, 1
02 centrally manages and distributes the chip rate and the number of spreading codes. More specifically, as shown in Table 2, the chip rate and the number of spreading codes are made to correspond to service requests categorized into four types: voice, data, image information, and image information. Voice, character data, and
The image has one spreading code, and the chip rates are T1 (voice), T2 (data and T3), respectively.
The three types of (image) chip rates are made to correspond. For example, the primary modulation before performing the spread spectrum processing is QP
SK, 32Kb when the spread spectrum is 32
ps voice, 128 Kbps data, 2 Mbps
, The chip rate is T1 =
512Kcps, T2 = 2Mcps, T3 = 32Mcp
s, and the chip rate is T3 = 3 for the image signal.
At 2 Mcps, three spreading codes are assigned.

By this means, 6 Mbps MPEG2
Signal switching becomes possible. As described above, according to the present invention, resources in a wireless section can be dynamically assigned according to various multimedia services requested by a node. Table 1 shows an embodiment of the resource management table of the master unit. In Table 1, wireless node 1 uses C1 as the spreading code, T1 uses the chip rate, and wireless node 2 uses C2 as the spreading code.
, T2 as the chip rate, C3, C4, C5 as the spreading code by the wireless node 3 and T3 as the chip rate.
Is assigned.

Next, the operation of the transmitting apparatus and the receiving apparatus in which the wireless node receives the resource assignment from the master and transmits / receives the data at a multi-rate in response to the resource assignment will be described with reference to FIGS.

First, with reference to FIG.
In the case (image signal service), the operation of the transmission device will be described. In the signaling mode, the resource assignment (chip rate and spreading code) from the master station is transmitted to the wireless ATM-M
The AC 10 receives and outputs the mode setting signals T _i and C _j to the chip rate setting unit 60 and the spreading code generation unit 50. The chip rate switching section 60 switches to a clock corresponding to the chip rate specified by the mode setting signal T _i and supplies the clock to the spreading code generator 50. The spreading code provided by the spreading code generator 50 in the mode setting signal C _j generated in accordance with the clock from the chip rate switching unit 60. In the case of the wireless node 3 shown in Table 1, the spreading code generator outputs C3,
Three spreading codes C4 and C5 are generated at a chip rate T3. In the communication mode, the image signal (6
Mbps) is received by the wireless ATM-MAC 10, packetized into a frame format in a wireless section, and passed to the serial / parallel converter 20. The serial / parallel converter 20 converts a 6 Mbps signal into a 2 Mbps parallel signal. The 2 Mbps signal is transmitted to the primary converters 30, 3
Multi-level modulation is performed at 1, 32. When QPSK is performed by the primary modulator, the symbol rate of the output signal of each primary modulator is 1 Ms
ps.

Next, each modulation signal is converted into a phase shifter 40,
1 and 42 are changed by a predetermined phase amount. In the present invention, a scheme is adopted in which three modulated signals are combined after spread spectrum, and despread at the receiving side to separate the three modulated signals.
In this case, it is necessary to perform mapping so that the S / N after the combination becomes the most advantageous.

The processing by the phase shifter performs this mapping. The output of each phase shifter is spread in spectrum spreaders 70, 71, 72. Here, as described above, spectrum spreading is performed at the chip rate T3 using the three spreading codes C3, C4, and C5 set at the time of signaling. At this time, the chip rate T3
Is T, where the code length of the spreading codes C3,.
3 = 1Mspsx32 = 32Mcps. The signal subjected to spectrum spreading by each spectrum spreader is added to the next adder 8.
The signal is added by 0, converted into an analog signal by a D / A converter 91, and transmitted to a radio unit 92 including a quadrature modulator. The above is the operation of the transmission device.

Next, the operation of the receiving apparatus will be described with reference to FIG. At the time of signaling in the receiving device as well as the transmitting device,
The wireless ATM-MAC 15 receives the chip rate T _i and the spreading code C _j specified by the master station,
And a setting signal to the spreading code generator 50. In the communication mode, the signal received by the antenna 95 is
, And is converted into a digital signal by the A / D converter 97.

This digital signal is supplied to correlators 85, 86,
It is despread at 87. At this time, it is assumed that the same code set C _j as the code set for despreading is set in the spreading code generator 50 in the transmitting apparatus, and the chip clock is timing-controlled and synchronized with the transmitting apparatus. The despread signal is corrected by the phase shifters 45, 46, and 47 by the amount of phase shift applied by the transmitting device.

Next, the signals are demodulated by the one-time demodulators 35, 36, and 37, and are converted into serial signals by the parallel / serial converter 25. This serial signal is A
Decomposed into TM cells and passed to the upper layer.

[0036]

As described above, the present invention has a multi-rate transmission / reception means by centrally managing resources on the radio base station side and combining chip rates and spreading code sets on the radio node side. , Wireless AT requiring transmission speed from low speed to high speed ranging from voice to image
There is an effect that efficient resource assignment can be performed in the M-LAN.

Also, due to the signaling, all the nodes in the service area cannot transmit until after the channel assignment from the master station is performed, and after the channel assignment is performed, the nodes are independent on the uplink and the downlink. Since communication is performed using a logical channel, there is an effect that hidden terminals can be prevented.

[Brief description of the drawings]

FIG. 1A is a configuration diagram of an embodiment of a wireless ATM LAN according to the present invention, and FIG. 1B is a schematic block diagram of a transmission device and a reception device of a wireless node.

FIG. 2 is an explanatory diagram showing correspondence between VPs and VCs on the ATM side and radio resources according to the present invention.

FIG. 3 is a block diagram of a transmission unit of the wireless node shown in FIG. 1;

FIG. 4 is a block diagram of a receiving unit of the wireless node shown in FIG. 1;

[Explanation of symbols]

 1 to 3 wireless node 10, 15 wireless ATM MAC 20 serial / parallel converter 25 parallel / serial converter 30 primary modulator 35 primary demodulator 40, 45 phase shifter 50 spreading code generator 60 chip rate switching unit 70 spectrum spreader Reference Signs List 80 adder 85 despreader 91 digital / analog converter 92, 96 wireless unit 93, 95 antenna

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location 9744-5K H04L 11/20 D

Claims (2)

[Claims] 1. A private ATM wireless LAN-LAN transmission method using a CDMA / FDD method as an access method of a wireless node in a service area managed by a base station as a base station connected to an ATM-SW. A step in which the master unit classifies resources of transmission media in the service area by using a combination of at least one spreading code and a chip rate in CDMA and manages a use state; and from a wireless terminal in the service area, Performing a resource allocation by a combination of a spreading code and a chip rate to the wireless terminal in response to a call request of the wireless terminal and a connection request from the ATM terminal on the ATM-LAN side to the wireless terminal. When the terminal receives designation of at least one spreading code and a chip rate from the master unit, it responds to the designation. Setting the transmission rate and the chip rate to the spread code and the chip rate. 2. A wireless ATM-LAN premises wireless transmission system in which a CDMA / FDD system is adopted as an access system of a wireless node in a service area managed by a base unit, which is a base station connected to an ATM-SW. A means for performing resource management of transmission media in the service area by using a combination of at least one spreading code and a chip rate in CDMA, and a call request from a wireless terminal in the service area; And means for allocating resources to the wireless node by a combination of a spreading code and a chip rate in response to a connection request from the ATM terminal on the ATM-LAN side to the wireless terminal, wherein the wireless node comprises: Receive at least one spreading code and chip rate from the corresponding spreading code and chip A private wireless transmission system in a wireless ATM-LAN, comprising: a transmission unit and a reception unit that optimize a transmission rate by setting a rate.