JPH09284862A - Mobile station for cordless telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a communication information amount by utilizing incoming slots after an incoming slot in a prescribed time after the reception of a logic control channel signal from a base station for communication channels to use physical slots used for logic control channels as communication channels. SOLUTION: A physical slot controller is provided with a function to switch a logic control channel and a communication channel till a succeeding time slot comes and a function generating a logic control channel missing transmission timing. When the controller is instructed by notice channel information as to 'an incoming logic control channel timing' from the base station 12 such that 'the base station 12 can receive incoming logic control channel signals only by an incoming slot in 2.5ms after an outgoing logic control channel used at present on the carrier used at present', the controller controls it that additional control channel information is not sent through the incoming slot in 2.5ms after the outgoing logic control channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless telephone mobile station, and more particularly to a PHS (Personal Handyphone Syst).
and a public base station in a simple mobile phone system called "em)".

[0002]

2. Description of the Related Art This type of telephone system is standardized as "second generation cordless telephone system" in "RCR STD-28" issued by the Radio Industry Association of Japan. The configuration of this system is "PS"
A mobile station such as a mobile phone and a base station called "CS", the mobile station performs land mobile radio communication with the base station or between mobile stations, and serves as a communication terminal device of a subscriber. Is also used, and the base station performs land mobile radio communication with the mobile station.

A radio access method of such a telephone system is based on TDMA / TDD (Time Domain Multiple Access / T).
It is a time division multiple access system called "ime Domain Duplex", and the number of multiplex is 4 when the full rate codec is applied.
The carrier frequency interval is 300 KHz and the transmission speed is 3
It is 84 Kbit / sec.

The channel structure of this system is roughly divided into a control channel (CCH) and an information channel (TCH). The control channel is a broadcast channel (BCCH), a paging channel (PCH), and an individual cell channel ( A common control channel (CCCH) having a CCCH) is provided, and an associated control channel (ACCH) is further provided. The broadcast channel is a downlink unidirectional channel for broadcasting control information from the base station to the mobile station. The associated control channel is a bidirectional channel associated with the information channel and transfers control information and user packet data necessary for call connection. An associated control channel that is always attached to an information channel is defined as a low-speed associated control channel (SACCH), and a channel that steals a temporary information channel and performs high-speed data transfer is defined as a high-speed associated control channel (FACCH).

In the TDMA system, a set of bit strings corresponding to physical channels multiplexed on the time axis is called a slot. The length of one slot is 0.625 ms. The control physical slot is commonly used by each user,
It is a slot in which a functional channel required for control such as setting of a physical slot for communication is set, and enables constant intermittent transmission only when it is on a control carrier. The communication physical slot is a slot used by each user exclusively for communication and in which a control channel and an information channel required for individual call setting control are set.

Referring to FIG. 4 which shows the structure of the communication slots of the radio channel of this telephone system, slots 5, 1, 6, are designated as "downlink" from the base station 12 to the mobile station 11.
A total of four slot rows of seven are transmitted intermittently. On the contrary, as the "uplink" from the mobile station 11 to the base station 12, a total of four slot rows of slots 8, 3, 9, and 10 are intermittently transmitted. Both slot sequences are collectively referred to as one time slot, and here, the case of eight time slots is shown. The eight time slots are when the logical control channel (LCCH) interval value n is eight.

The first slot 1 is used as a logical control channel for notifying the mobile station 11 of information for synchronization and control. This logical control channel has a fixed frequency so that any mobile station 11 can receive it.
Since the frequency is fixed, intermittent transmission is performed by using a plurality of time slots as a set so that a plurality of base stations can use it, and the frequency is effectively used. Here, the first
Slot 1 is transmitting only once in the 8 time slots and nothing is transmitting in each of the second slots 2 of the remaining 7 time slots.

On the other hand, the third slot 3 is received by the base station 12 as a logical control channel every 8 time slots. The logical control channel is a general term for channels used in a link channel establishment phase such as a broadcast channel, a paging channel and a dedicated cell channel.

Referring to FIG. 5, which shows a controller in such a conventional telephone system, one logical control channel controller 24 and one communication control channel
The controller 25 is provided, and one physical slot is used as a logical control channel, and one of the remaining three physical slots is used as a communication channel. One of the physical slots used as a logical control channel can be made variable. The logical control channel controller 24 has the ability to create the discontinuous reception timing of the logical control channel. The communication channel controller 25 does not correspond to the first physical slot controller 26, but corresponds only to the second physical slot controller 27.

In such a configuration, the physical slot transmitting the logical control channel is dedicated for control and cannot be used as a communication channel. Therefore,
Physical slot transmitting the logical control channel (first,
When a part of the second and third slots 1, 2, 3, etc.) is allocated for communication, it is possible to communicate in slots other than the slot transmitting the logical control channel (LCCH),
It has been found that the same speech quality deterioration as that in which one frame error occurs in n slots is sufficient.

[0011]

In view of the above problems and findings, the present invention provides a mobile station for a cordless telephone that achieves the following objects. (1) The physical slot transmitting the logical control channel is used as a communication channel to ensure the amount of communication information. (2) To prevent loss of control information of the communication channel. (3) Call quality should not be substantially degraded.

[0012]

The mobile station of the cordless telephone according to the present invention uses the upstream slots after the upstream slot after a predetermined time from the reception of the logical control channel signal from the base station as the communication channel. Particularly, control means for cutting the associated control channel signal is provided in the uplink slots after the uplink slot.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, which shows a communication slot configuration of an embodiment of the present invention, a third slot 3 is used as an "uplink" slot from a mobile station 11 to a base station 12.
Only the physical slot which is received as the logical control channel, and the fourth slot 4 in the seven time slots thereafter is a physical slot which is not newly received as the logical control channel. Since other configurations are common to those in FIG. 3, description thereof will be omitted.

In this embodiment, the base station 12 uses the "broadcast channel (BCCH) radio channel information broadcast" to
"Uplink Logical Control Channel (LCCH) Timing"
“The base station specifies that it is possible to receive the currently used downlink logical control channel on the currently used carrier.

As a result, the base station 12 can receive the upstream slot 4 after the upstream slot 3 2.5 ms after the downstream logical control channel as a communication channel. A so-called associated control channel (ACCH) that carries control information of the mobile station 11 using the communication channel can be transmitted even if the transmission timing of the logical control channel is removed by the base station 12 in the case of downlink, but In this case, since this channel is a random access, it is unknown whether the mobile station 11 will transmit the data for the time. Therefore, there is a concern that the base station 12 receives the logical control channel and cannot receive the associated control channel from the mobile station 11. The associated control channel is provided with a procedure for re-transmission so that communication can be performed, but in order to use the channel more efficiently, the following associated control channel is transmitted.

In the "broadcast channel radio channel information broadcast" from the base station 12, the "uplink logical control channel timing" is "the base station is on the carrier currently in use, and the downlink currently in use. 2.5 of the logical control channel
It is possible to receive the uplink logical control channel only in uplink slot 3 after ms ”and 2LCC
Even when H is used, the content of the "broadcast channel information broadcast" from the base station indicates that "the uplink logical control channel can be received only in the uplink slot 2.5 ms after the downlink logical control channel". The control is performed such that the associated control channel (the above FACCH, SACCH and similar communication channel control signals) information is not carried in the uplink slot 2.5 ms after the downlink logical control channel.

By using such a mobile station, it is possible to prevent the base station from transmitting the associated control channel signal of the communication channel at the timing of receiving and receiving the logical control channel, and there is no need to use a retransmission means. .

FIG. 2 showing the controller of this embodiment.
, One logical control channel controller 20 and one communication channel controller 21 are used, one physical slot is used for the logical control channel, and one of all four physical slots including this slot is used. Will also be used as a communication channel. One of the physical slots used as a logical control channel is variable. Physical slot controllers 22, 23
Has a function of switching the logical control channel and the communication channel by the next time slot and a function of creating the intermittent transmission timing of the logical control channel. In the broadcast channel information from the base station, "uplink logical control channel timing" , "The base station is on the currently used carrier, and is 2.5 of the currently used downlink logical control channel.
If it is specified that the uplink logical control channel can be received only in the uplink slot after ms, the control is performed so that the associated control channel information is not placed in the uplink slot 2.5 ms after the downlink logical control channel. .

That is, when the physical slot transmitting the logical control channel is used as the communication channel in a time division manner, the control information of the communication channel is not transmitted at the timing of the logical control channel.

On the base station side, the first slot 1 transmits the logical control channel signal only once in the eight time slots shown in FIG. 1, so that the subsequent seven slots do not transmit anything. , In the case of full rate (32 Kbits / name), the physical slot transmitting the logical control channel signal,
Not available for communication channel.

In order to solve this problem, there are a configuration in which the transmission of the logical control channel signal is stopped and used as a communication channel, and a configuration in which the transmission of the logical control channel signal is restarted when the use as the communication channel is finished. explain.

Regarding the allocation of the communication channel and the stop of the logical control channel, first, the logical control channel is transmitted in one physical slot, and the remaining three physical slots are further moved to the base station which is using the communication channel. When a new “link channel establishment request” is received from the station, the base station allocates the physical slot currently transmitting the logical control channel signal on the downlink dedicated cell channel (SCCH) to the mobile station in the “link channel allocation”. Is transmitted, the transmission of the logical control channel signal is stopped, a synchronous burst is transmitted and received as a communication channel in the physical slot, and a normal communication channel establishing procedure is executed. In this state, all four physical slots of the base station are used as communication channels.

Next, regarding the restart of the transmission of the logical control channel signal when the use of the communication channel is finished, the transmission of the logical control channel signal is stopped and all four physical slots of the base station are used as the communication channel. When the use of one or more physical slots as a communication channel is finished in the state where the base station is in the open state, the base station restarts transmission of the logical control channel signal.

At this time, if the physical slot that has finished being used as a communication channel is the physical slot that stopped the logical control channel signal at the time of assigning the communication channel, a normal transmission procedure such as checking the RSSI level is executed in this physical slot. After that, the transmission of the logical control channel signal is restarted.

However, in any case, when it is determined that the logical control channel signal is not suitable for transmission in the above-described normal transmission procedure, the same processing is performed in another physical slot. Also in this case, when the physical slot that is a candidate for the transmission slot of the logical control channel signal is used as the communication channel, the information channel (T
After the movement, the procedure for sending is executed using a procedure such as (CH) switching.

Referring to FIG. 3 showing the controller in this embodiment, one logical control channel controller 30 and four communication channel controllers 31, 3 are provided.
2, 33, 34 and four physical slot controllers 35, 36, 37, 38.

One physical slot can be used as a logical control channel, and four physical slots are used as communication channels. The position of the physical slot can be changed appropriately.

As described above, all the slots of the base station can be used as a communication channel without using a special mobile station.

Although the case where there are four physical slots is shown here, the present invention is not limited to this, and the communication channels can be similarly used in more than four physical slots.

[0030]

As described above, the mobile station of the cordless telephone of the present invention uses the uplink slots after the uplink slot after a predetermined time from the reception of the logical control channel signal from the base station as the communication channel. Therefore, particularly when all the slots of the base station are used as communication channels, there is an effect that loss of control information of the communication channels can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a communication slot according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a controller used in the mobile station of the embodiment.

FIG. 3 is a block diagram illustrating a controller used in a base station according to an embodiment.

FIG. 4 is an explanatory diagram showing communication slots of a conventional second-generation cordless telephone.

FIG. 5 is a block diagram showing a controller of a conventional mobile station.

[Explanation of symbols]

1-10 slot 11 mobile station 12 base station 20, 24, 30 logical control channel controller 21, 25, 31-34 communication channel controller 22, 23, 26, 27, 35-38 physical slot
controller

Claims (2)

[Claims] 1. A mobile station of a cordless telephone, characterized in that an up slot after an up slot after a predetermined time has elapsed from the reception of a logical control channel signal from a base station is used as a communication channel. 2. The mobile station of a cordless telephone according to claim 1, wherein a control means for cutting the associated control channel signal is provided in the uplink slot after the uplink slot.