Radio LAN system implementing simultaneous communication with different types of information and communication method for the same

• US 20020165989A1
• Filed: 04/25/2002
• Published: 11/07/2002
• Est. Priority Date: 05/02/2001
• Status: Active Grant

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Etoh, Hiroshi
• Granted Patent: US 7,058,113 B2
• Time in Patent Office: Days
• US Class Current: 709/248
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 47/24 Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/02 Data link layer protocols
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A radio LAN (Local Area Network) system includes an access point and a mobile or a fixed station each having a physical layer implemented by a direct spread spectrum system. The LAN system uses different spread codes, maintains transmission power semi-fixed, and selects a frequency and a frequency band in accordance with the kind and amount of information. A data link layer above each physical layer includes an LLC (Logical Link Control) sublayer and an MAC (Media Access Control) sublayer. The MAC sublayer uses a CDMA (Code Division Multiple Access) system as an access system for thereby implementing a data structure in accordance with the kind and amount of information.

Claims

1. A radio LAN (Local Area Network) system comprising an access point forming a limited service area and a station present in the limited service area for transmitting by radio an information signal between the access point and the station within the service area:

each of said access point and said station comprising;

a transmitter for spreading the information signal with a direct spread spectrum system, which spreads a frequency band width of the information signal, and transmitting a spread information signal; and

a receiver for receiving the spread information signal and inversely spreading said spread information signal;

said transmitter comprising;

a plurality of information transmitting circuits each for multiplying, in a direct spread spectrum system, the information signal and particular one of a plurality of spread codes; and

a transmission controller for selecting, in accordance with at least one of a kind and an amount of the information signal, one of frequency bands and frequencies respectively assigned to said plurality of information transmitting circuits and one of packets to use for transmission of the information signal, and maintaining transmission power of the spread information signal semi-fixed;

said receiver comprising;

a plurality of information receiving circuits each for detecting synchronization of the information signal received, multiplying the information signal detected by particular one of a plurality of codes for inverse spreading, said plurality of information receiving circuits determining a correlation between resulting multiplied information signals to restore the information signal originally sent from said transmitter; and

a receipt controller for maintaining received power of each spread information signal output from each of said plurality of information receiving circuits semi-fixed, and guaranteeing a level of the spread information signal;

said access point further comprising a first interface for connecting said access point to a wired LAN;

said station further comprising a second interfacing circuit for connecting said station to either one of a public switched telephone network and a terminal configured to process the information signal.

2. The system in accordance with claim 1, wherein the kind of the information signal is any one of a first control packet sent from said access point to said station, a second control packet sent from said station to said access point, and a channel packet for data and a channel packet for voice used by both of said access point and said station.

3. The system in accordance with claim 2, wherein said first packet comprises a field storing frame synchronization information of the first packet, an information field identifying said access point, a voice channel information field indicative of a channel number available for voice, a data channel information field indicative of a channel number available for data, a control information field indicative of various kinds of request control, and a control data field storing error control data of the first control packet,

the control information field storing location confirmation request information for requesting confirmation of a location of said station present in the service area, registration request information for requesting registration of said station newly entering the service area, call information for requesting communication from said access point to said station, and report information indicative of channel release.

4. The system in accordance with claim 2, wherein the second control packet comprises a field storing frame synchronization information of the second control packet, an information field identifying said station, a field storing error control data of the second control packet, and a control information field indicative of various kinds of request control,

said control information field storing location confirmation acknowledgement information for answering the location confirmation request information, registration acknowledgement information for answering the registration request information when said station newly enters the service area, call acknowledgement information for answering the call request information, communication request information for requesting communication with said access point, and report information indicative of channel release.

5. The system in accordance with claim 2, wherein the channel packet for data comprises a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source having sent the information signal, a storage information field indicative of an amount of data of the information signal stored, a field storing the information signal, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field, the storage information field and the storage field being variable in size.

6. The system in accordance with claim 2, wherein the channel packet for voice comprises a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage field storing the information field, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field and the storage fields being fixed in size.

7. The system in accordance with claim 2, wherein the first packet comprises a field storing frame synchronization information of the first packet, an information field identifying said access point, a voice channel information field indicative of a channel number available for voice, a data channel information field indicative of a channel number available for data, a control information field indicative of various kinds of request control, and a control data field storing error control data of the first control packet,

the control information field storing location confirmation request information for requesting confirmation of a location of the station present in the service area, registration request information for requesting registration of said station newly entering the service area, call information for requesting communication from said access point to said station, and report information indicative of channel release,

the second control packet comprising a field storing frame synchronization information of the second control packet, an information field identifying said station, a field storing error control data of the second control packet, and a control information field indicative of various kinds of request control,

the control information field of the second control packet storing location confirmation acknowledgement information for answering the location confirmation request information, registration acknowledgement information for answering the registration request information when said station newly enters the service area, call acknowledgement information for answering the call request information, communication request information for requesting communication with said access point, and report information indicative of channel release,

the channel packet for data comprising a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage information field indicative of an amount of data of the information signal stored, a field storing said information signal, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field, the storage information field and the storage field of the channel packet for data being variable in size,

the channel packet for voice comprising a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage field storing the information field, and a storage field storing error control data of the channel packet, and

each of the destination information field, the source information field and the storage fields of the channel packet for voice being fixed in size.

8. The system in accordance with claim 7, wherein said access point further comprises a connecting circuit for connecting said access point to a radio access apparatus.

9. The system in accordance with claim 7, wherein said access point and said station each are operable in a TDD (Time Division Duplex) mode particular to an IMT-2000 system.

10. A method of transmitting an information signal by radio between an access point and a station present in a limited service area in a radio LAN system, comprising the steps of:

setting up, as an access system between the access point and the station, a CDMA (Code Division Multiple Access) system using a plurality of spread codes for spreading the information signal;

maintaining transmission power of the information signal spread semi-fixed;

selecting, in accordance with a kind and an amount of the information signal, a frequency band and a frequency to be assigned to the information signal and a structure of a packet for transmitting the information signal; and

transmitting the information signal in accordance with a transmission procedure.

11. The method in accordance with claim 10, wherein said transmission procedure comprises:

a first step of causing the access point to transmit preselected control information to the station present in the service area;

a second step of causing the station to monitor a radio wave being sent from the access point and containing the preselected control information, and transmit to the access point an acknowledgement signal showing that the station has selected the greatest electric field strength of the radio wave;

a third step of causing the access point to determine, on receiving the acknowledgement signal from the station, whether or not the station is present in the service area;

a fourth step of causing the access point to transmit to the station a new registration request for newly requesting registration of the station present in the service area;

a fifth step of causing the station to transmit, on receiving the new registration request, an acknowledgement of receipt of the new registration request to the access point;

a sixth step of causing the access point to show, while determining whether or not the station registered is present in the service area, channel information representative of an idle channel when an access request is transmitted from the access point to the station or from the station to the access point, update the channel information, and send out updated channel information;

a seventh step of causing, when a transmission request is transmitted from an apparatus connected to the station to the station, the station to select a channel in accordance with the updated channel information, send a transmission request to the access point, and transmitting an information signal with a preselected format to the access point in response to an acknowledgement signal that is received from the access point within a preselected period of time;

an eighth step of causing, when an existing LAN connected to the access point sends a call request to the access point, the access point to determine whether or not the station designated by destination information included in an information signal is present in the service area, assign the channel information to the station if the station is present in the service area to thereby call the station, and transmit an information signal with a preselected format to the station in response to an acknowledgement signal that is received from the station within a preselected period of time;

a ninth step of causing, when the preselected period of time expires before receipt of the acknowledgement signal from the access point or when a terminal connected to the station transmits end-of-communication information to the station, the station to transmit information indicative of a releases of the channel to the access point or the terminal, respectively; and

a tenth step of causing, when the preselected period of time expires before receipt of the answer signal from the station or when the existing LAN transmits end-of-communication information to the access point, the access point to transmit information indicative of a release of the channel to the station or the existing LAN, respectively.

12. The method in accordance with claim 11, wherein the preselected control information comprises a first control packet to be transmitted from the access point to the station and a second control packet to be transmitted from the station to the access point,

the first packet comprising a field storing frame synchronization information of the first packet, an information field identifying the access point, a voice channel information field indicative of a channel number available for voice, a data channel information field indicative of a channelnumber available for data, a control information field indicative of various kinds of request control, and a control data field storing error control data of the first control packet,

the control information field storing location confirmation request information for requesting confirmation of a location of the station present in the service area, registration request information for requesting registration of the station newly entered the service area, call information for requesting communication from the access point to the station, and report information indicative of channel release,

the second control packet comprising a field storing frame synchronization information of the second control packet, an information field identifying the station, a field storing error control data of the second control packet, and a control information field indicative of various kinds of request control,

the control information field of the second control packet storing location acknowledgement information for answering the location registration request information, registration acknowledgement information for answering the registration request information when the station newly enters the service area, call acknowledge information for answering the call information, communication request information for requesting communication with the access point, and report information indicative of channel release.

13. The method in accordance with claim 11, wherein the information signal with the preselected format comprises a channel packet for data and a channel packet for voice used by both of the access point and the station,

the channel packet for data comprising a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage information field indicative of an amount of data of the information signal stored, a field storing the information signal, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field, the storage information field and the storage field of the channel packet for data being variable in size,

the channel packet for voice comprising a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage field storing the information field, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field and the storage fields of the channel packet for voice being fixed in size.

14. The method in accordance with claim 11, wherein the station belongs to a first class if mobile or to a second class if fixed, as determined by the access point by location confirmation,

the preselected control information being repeatedly transmitted to the first class at a period several hundred thousand times as long as a period at which the preselected control information is repeatedly transmitted to the second class.

15. The method in accordance with claim 13, wherein the station belongs to a first class if mobile or to a second class if fixed, as determined by the base station by location confirmation,

the preselected control information being repeatedly transmitted to the first class at a period several hundred thousand times as long as a period at which the preselected control information is repeatedly transmitted to the second class.

16. The method in accordance with claim 11, wherein the preselected control information comprises a first control packet to be transmitted from the access point to the station and a second control packet to be transmitted from the station to the access point,

the first packet comprising a field storing frame synchronization information of the first packet, an information field identifying the access point, a voice channel information field indicative of a channel number available for voice, a data channel information field indicative of a channel number available for data, a control information field indicative of various kinds of request control, and a control data field storing error control data of the first control packet,

the control information field storing location request information for requesting confirmation of a location of the station present in the service area, registration request information for requesting registration of the station newly entering the service area, call information for requesting communication from the access point to the station, and report information indicative of channel release,

the second control packet comprising a field storing frame synchronization information of the second control packet, an information field identifying the station, a field storing error control data of the second control packet, and a control information field indicative of various kinds of request control,

the control information field storing location confirmation acknowledgement information for answering the location confirmation request information, registration acknowledge information for answering the registration request information when the station newly enters the service area, call acknowledgement information for answering the call information, communication request information for requesting communication with the access point, and report information indicative of channel release,

the information signal with the preselected format comprising a channel packet for data and a channel packet for voice used by both of the access point and the station,

the channel packet for data comprising a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage information field indicative of an amount of data of the information signal stored, a field storing the information signal, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field, the storage information field and the storage field of the channel packet for data being variable in size,

the channel packet for voice comprising a field storing frame synchronization information of the channel packet, a destination information field identifying a destination of the information signal, a source information field identifying a source sent the information signal, a storage field storing the information field, and a storage field storing error control data of the channel packet,

each of the destination information field, the source information field and the storage fields of the channel packet for voice being fixed in size.

17. The method in accordance with claim 16, wherein the station belongs to a first class if mobile or to a second class if fixed, as determined by the base station by location confirmation,

the preselected control information being repeatedly transmitted to the first class at a period several hundred thousand times as long as a period at which the preselected control information is repeatedly transmitted to the second class.