AU780972B2

AU780972B2 - Radio communication system and radio communication method and main phone for use therein

Info

Publication number: AU780972B2
Application number: AU65450/01A
Authority: AU
Inventors: Mikio Fukushi
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2000-08-30
Filing date: 2001-08-24
Publication date: 2005-04-28
Anticipated expiration: 2021-08-24
Also published as: JP2002078008A; JP3481569B2; AU6545001A

Description

S&F Ref: 567733

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant Actual Inventor(s): Address for Service: Invention Title: NEC Corporation 7-1, Shiba Minato-ku Tokyo Japan Mikio Fukushi Spruson Ferguson St Martins Tower,Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Radio Communication Syptem and Radio Communication Method and Main Phone for Use Therein r The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c 1 RADIO COMMUNICATION SYSTEM AND RADIO COMMUNICATION METHOD AND MAIN PHONE FOR USE THEREIN BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a radio communication system and a method thereof and a main phone for use therein and, more particularly, to a radio communication system in which a plurality of child phones conduct multi-channel access communication with a main phone connected to an ISDN line by using two radio channels.

DESCRIPTION OF THE RELATED ART In recent years, there is a wide spread of digital cordless data communication systems using personal handy phone systems (PHS). At home, at offices, I etc., in particular, realized between a main phone as a customer-owned base station and a child phone as a oO.* ""mobile station thereof is a system in which the child phone dials to connect to a common analog line or an ISDN and access the Internet via the main phone by using PIAFS (PHS Internet Access Forum Standard). Between child phones, data communication through extension is possible. In this case, as a radio transmission speed of 25 a radio line between a main phone and a child phone, 32 kbps and 64 kbps data communications are realized.

In conventional systems, however, design of a 2 radio unit and a channel CODEC allows a main phone to use only two channels at the same time as a data channel because of costs unlike common public base stations. In other words, when the main phone and a child phone execute 64 kbps communication, other child phones are not allowed to communicate with the main phone.

The first problem is as follows. In a case where a plurality of child phones are registered at a main phone and they are located in a communication area of the main phone, when a certain child phone and the main phone conduct 64 kbps communication, even if other child phone sends a link channel set-up request, the main phone refuses assignment because no channel is free.

However, the child phone receiving the refusal of assignment can not find which child phone is in use and why the child phone itself is not allowed to connect because as a reason for refusal, only such message as that all of CS (Cell Station: main phone in this example) slots are in use or that no CS free channel exists is defined based on personal handy phone communication standard (RCR STD -28 3.2 edition).

"'"The second problem is that when 64 kbps communication is conducted between a main phone and a certain child phone, other child phones are disabled to connect to the main phone, so that data communication from other child phones is not enabled until communication under way with the child phone in question is completed.

There is a need to provide a communication system which makes it possible with ease to find, when with two s radio channel (64 kbps) communication being executed between a main phone and a certain child phone, other child phone sends a link channel set-up request to the main phone, which child phone is in use and why the child phone itself is not connectable and a method thereof, and a main phone for use therein.

There is a further need to provide a communication system which enables, even when with two radio channel (64 kbps) communication being executed between a main phone and a certain child phone, other child phone sends a link 1s channel set-up request to the main phone, communication with the main phone upon a further request and a method thereof, and a main phone for use therein.

SUMMARY

According to the first aspect of the invention, a radio communication system having a plurality of child phones and a main phone connected to a communication line to conduct communication with the child phones using two radio channels, wherein while the main phone communicates with one of the child phones using the two channels, assignment refusal [R:\L11CC14611 .doc:fvIC 4 reason information including identification information of the child phone currently in communication and transmission speed information of the same is notified in response to a link channel assignment request from other child phone to display the assignment refusal reason information in question on the other child phone notified.

In the preferred construction, the main phone has means for notifying the assignment refusal reason information to the other child phone whose assignment is refused, and the child phone has display means for visually displaying the assignment refusal reason information from the main phone.

In another preferred construction, the main phone includes a control unit for providing control such that one of the two channels used for the child phone in communication is assigned to the communication with the other child phone in response to a link channel assignment request repeated by the other child phone.

20 In another preferred construction, the control 2C. unit of the main phone assigns one of the two channels used for the child phone in communication to the communication with the other child phone upon a second link channel assignment request from the other child phone.

In another preferred construction, the main phone includes a notification history storage unit for storing 5 a history of communication with the child phones and referring to the notification history in the notification history storage unit, determination is made whether a link channel assignment request from the other child phone is repeated or not.

According to the second aspect of the invention, a main phone connected to a communication line to conduct communication with a plurality of child phones using two radio channels, which while communicating with one of the child phones using the two channels, notifies assignment refusal reason information including identification information of the child phone currently in communication and transmission speed information of the same in response to a link channel assignment request from other child phone.

In the preferred construction, the main phone may include a control unit for providing control such that one of the two channels used for the child phone in communication is assigned to the communication with the other child phone in response to a link channel assignment request repeated by the other child phone.

In another preferred construction, the control unit of the main phone assigns one of the two channels used for the child phone in communication to the communication with the other child phone upon a second link channel assignment request from the other child 6 phone.

In another preferred construction, the main phone includes a notification history storage unit for storing a history of communication with the child phones and referring to the notification history in the notification history storage unit, determination is made whether a link channel assignment request from the other child phone is repeated or not.

According to a further aspect of the invention, a radio communication method in a radio communication system having a plurality of child phones and a main phone connected to a communication line to conduct communication with the child phones using two radio channels, wherein the main phone has a step of, while communicating with one of the child phones using the two channels, notifying assignment refusal ••go :.:":reason information including identification information of the child phone currently in communication and transmission speed information of the same in response to a link channel assignment request from other child phone, and *the child phone has a step of displaying the assignment refusal reason information notified by the main phone.

In the preferred construction, the main phone has an assignment control step of providing control such 7 that one of the two channels used for the child phone in communication is assigned to the communication with the other child phone in response to a link channel assignment request repeated by the other child phone.

In another preferred construction, at the control step of the main phone, one of the two channels used for the child phone in communication is assigned to the communication with the other child phone upon a second link channel assignment request from the other child phone.

In another preferred construction, the main phone has a step of determining whether a link channel assignment request from the other child phone is repeated or not with reference to the notification history in the •..-notification history storage unit for storing a history of communication with the child phones.

According to a still further aspect of the invention, a radio communication program for controlling radio communication having a plurality of child phones and a main phone connected to a communication line to conduct communication with the child phones using two Soradio channels, wherein the radio communication program for the main phone has a function, while communicating with one of the child phones using the two channels, notifying assignment refusal 8 reason information including identification information of the child phone currently in communication and transmission speed information of the same in response to a link channel assignment request from other child phone, and the radio communication program for the child phone has a function of displaying the assignment refusal reason information notified by the main phone.

Operations of the present invention will be described. During communication (64bkps communication) between a main phone and a certain child phone using two radio channels, when a link channel assignment request is made by other child phone, the main phone sends a link channel assignment refusal message with an extension number of the child phone in communication and a newly defined transmission speed attached as a reason for the refusal in the message to notify to the child phone. The child phone is structured to display the refusal reason on a display unit at the main body of the phone itself or on a data terminal such as a PC (personal computer) connected to the child phone.

In addition, during 64 kbps communication between the main phone and a certain child phone, when a further link channel assignment request is made by other child phone, the main phone disconnects a second radio channel (Tch) which is a communication channel with the child 9 phone in communication to maintain 32 kbps communication using a first radio channel (Tch) between the main phone and the child phone and sends a link channel assignment to other child phone to realize a 32 kbps communication line using the second radio channel (Tch) between the main phone and other child phone in question.

Other objects, features and advantages of the present invention will become clear from the detailed description given herebelow.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.

In the drawings: .Fig. 1 is a diagram showing a schematic system structure applied to an embodiment of the present invention; Fig. 2 is a block diagram showing a structure of a main phone; Fig. 3 is a block diagram showing a structure of a child phone; Fig. 4 is a sequence diagram showing part of operation of the embodiment of the present invention; 10 Fig. 5 is a sequence diagram showing part of operation of the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the present invention will be discussed hereinafter in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, wellknown structures are not shown in detail in order to unnecessary obscure the present invention.

Fig. 1 is a diagram showing a schematic structure of a communication system to which the embodiment of the present invention is applied. In fig. i, a main phone is connected to a PSTN (Public Switched Telephone Network) or an ISDN (Integrated Services Digital 20 Network) not shown through a cable 40 and child phones [[20a and 20b are connectable to an access point of the Internet and the like through a line wire via the main phone The main phone 10 is a simple customer-owned base station which conducts operation of a customer-owned base station and has two channels as a communication channel at the same time. The main phone 10 has a 64 11 kbps PIAFS communication control function for use in data communication of a personal handy phone other than a radio base station channel CODEC function. The child phones 20a and 20b are child phone terminals conformed to the customer-owned phone and registered at the system of the main phone 10 in advance. The child phones and 20b have the equivalent functions and have the radio channel CODEC and 64 kbps PIAFS communication control functions. The child phone is ordinarily connected to a PC not shown and is enabled to activate dialing and reception of call and transmit and receive data under the control of the PC.

Next, description will be made of an internal system block of the main phone 10 with reference to Fig.

2. A radio unit part 14 is a part having a function of too* converting a frequency to a 1.9 GHz band and too 0 transmitting and receiving data to and from a child 9:06 6% phone side through a radio line. A channel CODEC unit 13 conducts assignment of a communication channel to a time slot on a radio line and disassembly/assembly of a control channel and a communication channel.

too.

A PIAFS control unit 12 conducts generation and disassembly of a PIAFS frame and PIAFS control. PIAFS supports 32 kbps and 64 kbps PISAFS data communications.

A line interface unit 11 has a network control function for the connection to an external PSTN or an ISDN. In charge of control of these units as a whole is a control 12 unit Next, description will be made of an internal system block of the child phone with reference to Fig. 3.

While in this example, description will be made of the child phone 20a, it is clearly understood that the child phone 20b has completely the same structure. In Fig. 3, a radio unit part 24 transmits and receives data to and from the main phone 10 through a radio line. A channel CODEC unit 23 conducts assignment of a communication channel to a time slot on a radio line and disassembly/assembly of a control channel and a communication channel.

A PIAFS control unit 22 conducts generation and disassembly of a PIAFS frame and PIAFS control. As described in the foregoing, PIAFS supports 32 kbps and 64 kbps PIAFS data communications. A DTE interface unit i 21 has a PC connection interface function and has RS232C or PCMCIA card interface or the like. A display unit 26 is a part for displaying a state of a child phone, which is an LCD (liquid crystal display device), LED (lightse*e* emitting diode) or the like. In charge of control of @see.

these units as a whole is a control unit Next, radio communication operation according to the above-described present embodiment will be described 25 with reference to the sequence diagrams of Figs. 4 and

SOS

Fig. 4 is a sequence diagram of channels of the main phone 10, the child phone 20a and the child phone 13 Assume that Cch denotes a control channel, a first Tch denotes a 32 kbps communication channel 1 and a second Tch denotes a 32 kbps communication channel 2.

Assume that when the main phone 10 and the child phone 20a conduct 64 kbps data communication using the first Tch and the second Tch (Steps Sl and S2), the child phone 20b sends a link channel set-up request to the main phone 10 through the control channel Cch (Step S3).

In this case, assume that the main phone notifies the child phone 20b of refusal of link channel assignment (Step S4) because there is no free usable channel and that its frame has an 8-bit area for recording refusal reason information, in which the main 15 phone 10, the child phone 20a and the child phone define in advance an extension number of a child phone in communication and a transmission speed for connection with the main phone 10 according to bit coding of this 8-bit information. Define bit coding, for example, as follows.

[10000000]: extension number 10, 64 kbps communication coo.

[10000001]: extension number 11, 64 kbps communication Assume that the extension number (child phone identification information) 10 corresponds to the child phone 20a and the extension number (child phone identification information) 11 corresponds to the child phone 20b and that the respective extension numbers are 14numbers registered at the main phone The child phone 20b analyzes 8 bits of the refusal reason information of the received link channel assignment refusal. If the 8-bit refusal reason information is [10000000], information that the extension number 10 is conducting 64 kbps communication is displayed on the display unit 26 of the child phone The information that the extension number 10 is conducting 64 kbps communication may be displayed on a PC via the DTE interface unit 21.

Next, with reference to the sequence diagram of Fig. 5, even when a link channel set-up request from the child phone 20b is refused while 64 kbps data communication is conducted between the main phone 10 and 5 the child phone 20a, if a further link channel set-up request is received from the child phone 20b (Step S7) during communication with the child phone 20a (Steps and S6), a disconnection sequence for the second Tch of •the child phone 20a is activated by the main phone (Step S8) to release the second Tch. The main phone and the child phone 20a accordingly enter the state of the 32 kbps data communication using the first Tch (Step S9).

Recording all the histories of communication with the child phones 20a and 20b in a communication history storage unit 16 formed of a storage medium such as a memory shown in Fig. 2 enables the main phone 10 to find that after a link channel assignment was refused, the child phone 20b has made a further link channel set-up request.

Then, the main phone 10 notifies the child phone 20b of link channel assignment (Step 10). Thereafter, the main phone 10 and the child phone 20b execute a call setting sequence (Step SlI) to enter the state of 32 kbps data communication using the second Tch (Step S12).

Thus, when the main phone 10 receives a link channel assignment request from the child phone during 64 kbps data communication between the child phone 20a and the main phone 10, the main phone notifies a link channel assignment refusal because no free usable channel exists, while notifying the 15 extension number of the child phone 20a and a data transmission speed as a reason for the refusal, which enables the child phone 20b to determine which child phone in communication hinders its connection based on the received reason for the refusal. In addition, when the main phone 10 receives a further link channel set-up request from the child phone 20b during communication with the child phone 20a, the main phone 10 cuts off the second Tch with the child phone 20a to continue data .i communication with the child phone 20a by 32 kbps, while notifying the child phone 20b of link channel assignment, thereby enabling 32 kbps data communication with the child phone 16 By thus notifying a child phone which can not be connected of detailed reasons in the present invention, if a child phone at a 64 kbps connection state is not actually conducting transmission and reception of data but is simply at a connection idle state, an operator is enabled to advice the child phone 20a about disconnection, which makes efficient communication possible.

In addition, even when the child phone 20a is at a data transmission and reception state, if the child phone 20b gives notification of a further link channel assignment, the main phone is allowed to ensure a free channel by slowing down a connection line speed from 64 kbps to 32 kbps, so that the main phone can ensure 32 15 kbps data communication with the child phone simultaneously with the child phone While the number of child phones here is two, it is clearly understood that it may be three or more.

Although the foregoing description is made of a case where when a child phone whose request is once refused makes a second link channel assignment request, communication by one of the communication channels being connected is cut off to connect the child phone making the assignment request by the communication channel in question, the number of link channel assignment requests at which the assignment is allowed is not limited to the above-described second request. For example, it can be 17 appropriately changed according to the number of child phones of the radio communication system, communication frequency, etc. and it may be third request or more.

The above-described radio communication system can be realized not only as hardware but also as software by a control program for implementing each of the above-described functions which is recorded in a magnetic disc, a semiconductor memory or other recording medium of a computer system. The control program is read from the recording medium into data processing units (CPU) of a main phone and a child phone to control operation of the data processing units, thereby realizing the above-described function of each means.

As described in the foregoing, an embodiment of the present invention attains che following effects.

o* First, during 64 kbps data communication between a main phone and a child phone, upon reception of a channel assignment request from other child phone, the main phone notifies an extension number of the child 20 phone in communication and information about a speed of transmission to the main phone as a reason for refusal recorded in a channel assignment refusal frame, thereby making clear for what reason the refused child phone can not be connected and making a communication state of other child phone be found. As a result, if a child phone at a 64 kbps connection state conducts neither data transmission nor reception but is simply at a 18 connection idle state, an operator can advice the child phone in question about disconnection.

Secondly, upon receiving a further channel assignment request from a child phone whose assignment is refused, by changing the channel of a child phone in 64 kbps data communication to 32 kbps, the main phone is allowed to enter a state where data transmission and reception to and from two child phones simultaneously is enabled without waiting for the child phone in communication to be disconnected.

Although the invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and 15 additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodies within a scope encompassed and "equivalents thereof with respect to the feature set out in the appended claims.

Claims

2. The radio communication system as set forth in claim i, wherein said main phone has means for notifying said assignment refusal 5 reason information to said other child phone whose assignment is refused, and said child phone has oo• display means for visually displaying said assignment refusal reason information from said main phone. 20
3. The radio communication system as set forth in claim 1, wherein said main phone includes a control unit for providing control such that one of the two channels used for said child phone in communication is assigned to the communication with said other child phone in response to a link channel assignment request repeated by said other child phone.
4. The radio communication system as set forth in claim 3, wherein said control unit of said main phone assigns one of the two channels used for said child phone in communication to the communication with said other child phone upon a second link channel assignment request from said other child phone. The radio communication system as set forth in S•claim 3, wherein said main phone includes a notification history storage unit for storing a history of communication with said child phones and referring to the notification history in said notification history storage unit, S. determination is made whether a link channel assignment request from said other child phone is repeated or not. A main phone connected to a communication line to 21 conduct communication with a plurality of child phones using two radio channels, which while communicating with one of said child phones using said two channels, notifies assignment refusal reason information including identification information of the child phone currently in communication and transmission speed information of the same in response to a link channel assignment request from other child phone.
7. The main phone as set forth in claim 6, which includes a control unit for providing control such that one of the two channels used for said child phone in 5 communication is assigned to the communication with said other child phone in response to a link channel assignment request repeated by said other child phone.
8. The main phone as set forth in claim 7, wherein said control unit of said main phone assigns one of the two channels used for said child phone in communication to the communication with said other child 5 phone upon a second link channel assignment request from S. said other child phone.
9. The main phone as set forth in claim 7, wherein said main phone includes a notification history 22 storage unit for storing a history of communication with said child phones and referring to the notification history in said notification history storage unit, determination is made whether a link channel assignment request from said other child phone is repeated or not. A radio communication method in a radio communication system having a plurality of child phones and a main phone connected to a communication line to conduct communication with said child phones using two radio channels, wherein said main phone has a step of, while communicating with one of said child phones using said two channels, notifying assignment refusal reason information including identification information of the child phone currently in communication and transmission speed information of the same in response to a link channel assignment request from other child phone, and said child phone has a step of 15 displaying said assignment refusal reason information notified by said main phone.
11. The radio communication method as set forth in claim 10, wherein said main phone has an assignment control step of providing control such that one of the two channels used 23 for said child phone in communication is assigned to the communication with said other child phone in response to a link channel assignment request repeated by said other child phone.
12. The radio communication method as set forth in claim 11, wherein at said control step of said main phone, one of the two channels used for said child phone in communication is assigned to the communication with said other child phone upon a second link channel assignment request from said other child phone.
13. The radio communication method as set forth in claim 11, wherein said main phone has a step of determining whether a link channel assignment request from said other child phone is repeated or not S"with reference to said notification history in the notification history storage unit for storing a history ."of communication with said child phones. A radio communication program for controlling radio communication having a plurality of child phones and a main phone connected to a communication line to conduct communication with said child phones using two radio channels, wherein 24 said radio communication program for said main phone has a function, while communicating with one of said child phones using said two channels, notifying assignment refusal reason information including identification information of the child phone currently in communication and transmission speed information of the same in response to a link channel assignment request from other child phone, and said radio communication program for said child phone has a function of displaying said assignment refusal reason information notified by said main phone.
15. The radio communication program as set forth in claim 14, wherein said radio communication program for said main phone has an assignment control function of providing 5 control such that one of the two channels used for said child phone in communication is assigned to the communication with said other child phone in response to a link channel assignment request repeated by said other child phone.
16. The radio communication program as set forth in claim 15, wherein in said assignment control function of said main 25 phone, one of the two channels used for said child phone in communication is assigned to the communication with said other child phone upon a second link channel assignment request from said other child phone.
17. The radio communication program as set forth in claim 15, wherein said radio communication program for said main phone has a function of determining whether a link channel assignment request from said other child phone is repeated or not with reference to said notification history in the ,49r notification history storage unit for storing a history '0*SO of communication with said child phones. o
18. A radio communication system substantially as herein described with reference ~to an embodiment shown in Figs. I to 5 of the accompanying drawings. got**:
19. A main phone substantially as herein described with reference to an embodiment shown in Figs. 1 to 5 of the accompanying drawings. A radio communication method, said method substantially as herein described with reference to an embodiment shown in Figs. 1 to 5 of the accompanying drawings. 5555 DATED this Twenty-second Day of August, 2001 NEC Corporation Patent Attorneys for the Applicant SPRUSON FERGUSON