JP3475065B2 - Outgoing / incoming call system with superframe synchronization - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication method between a base station and a mobile terminal or a relay station, and more particularly to a method for making and receiving calls by superframe synchronization of a control channel. 2. Description of the Related Art At present, multiplexing by time division and two-way communication are adopted as communication methods of mobile terminals such as PHS, and FIG. 3 is a diagram showing a relationship between a base station and mobile terminals in a paging area. It is. As shown, a plurality of base stations 1, a base station 2, a base station 3, a base station 4,... Are installed in a paging area pg1, which is a paging area. Connected to the telephone network. Other paging area pg2
Are similarly configured. Each of the base stations 1, 2, 3, and 4 has its own service area 1-1, 2-1, 3-1 and 4-1. -1,
Communication is performed with the mobile terminals in 4-1 through a time-division multiplexing control channel to maintain constant communication. FIG. 2 is a diagram showing control channel signals of a conventional mobile terminal and a base station in a call waiting state. As shown in the figure, four consecutive slots (# 1 to # 4 slots, 1 slot width = 6.25 μs) are alternately used as a transmission slot and a reception slot as control slots of the base station (FIG. 2). (B)). The base station constantly and intermittently transmits control signals to mobile terminals using the transmission slots. FIG.
(A) shows a logical control channel. As shown in the figure, when the number of logical control channels is 8, the broadcast channel (BC channel) indicating the start of system information, eight incoming information channels (P1 to P8 channels), and three channel allocation controls A total of 12 channels (this is referred to as an LCCH superframe) of a dedicated channel (SC channel) are repeatedly and intermittently transmitted at a cycle of 1.2 seconds.
Between the base stations, transmission is performed at the timing of a 5 ms frame (6.25 μs × 8 slots) in the transmission and reception slots to improve the wireless use efficiency. [0005] Each mobile terminal calculates a paging group to which the mobile station belongs based on the structure of the superframe and its own terminal number (fixed), and a corresponding paging information channel P (P in the above figure).
1 to P8), the power consumption during standby can be saved (FIG. 2).
(C)). The operation of the system will be described with reference to FIG. The mobile terminal 12 has a paging area pg which is a paging area.
When it enters 1, it transmits its own number using the control channel (uplink), so that it transmits to the center 10 via the base station 1 (the station where the radio wave condition is good and connectable) and the exchange 11 with which it communicates. Your location is registered (this is registered automatically). The mobile terminal 12 always receives the incoming information channel P1 of the control channel of the base station 1 (its assigned channel).
Receiving and waiting for your incoming call. When there is a call from the telephone network or another mobile terminal to the mobile terminal 12, the center 10 checks the registered position and moves from the base stations in the paging area pg1 via the exchange 11 at once. It transmits incoming information to the terminal 12 through the control channel. Since the mobile terminal 12 has received the incoming information channel P1 of the base station 1, it can respond. When the mobile terminal 12 moves to another paging area pg2, the position is re-registered and the same operation is performed. [0008] However, in the conventional method, the mobile terminal receives a call from a certain base station (base station 1 in the above description) in the paging area in which location registration is performed for receiving a call. Control channel is being received. Therefore, when an error occurs in the received information due to a radio condition or the like, the incoming call processing may not be activated. Further, even if the incoming call can be recognized, the accessing base station may be rejected for connection due to no wireless or wired vacant line, and as a result, the incoming call may not be connected. [0009] Similarly, at the time of calling, if the accessed base station is busy (known from the incoming call information), another base station is searched and access is attempted again. All base stations may be busy and unable to make outgoing calls. [0010] In addition, there is a high possibility that a connection delay due to an access retry occurs even when the connection is lucky, and there is a problem that the connection is terminated when a certain delay time is exceeded. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide an incoming / outgoing call system based on superframe synchronization in which connection to an incoming call is made quickly and reliably and power consumption is low, in order to eliminate the above problems. Aim. [0012] In order to solve the above-mentioned problems, the present invention is directed to a paging area comprising a plurality of base stations, wherein the plurality of base stations synchronize the slot timing of a control channel, In an originating and terminating system based on superframe synchronization in which information on a superframe of a control channel is periodically intermittently transmitted to communicate with a mobile terminal or a relay station, each base station in an adjacent service area has a supermarket. shifting the slot timing of the frame, it is empty channel
In the incoming information channel on the superframe without
Means for transmitting a message including information indicating that the mobile terminal or the relay station is on the superframe of each base station.
A means for intermittently receiving an incoming information channel and waiting for an incoming call; and an incoming call when calling any of the base stations.
Make a call to a base station with an empty channel based on the information channel
And means for performing the operation. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing control channel signals of a mobile terminal and a base station in an incoming call waiting state in the outgoing / incoming call method of the present invention. As shown in the figure, the outgoing / incoming call method of the present invention uses a plurality of base stations (base station 1,
It is characterized in that control channels from the base station 2 and the base station 3) are simultaneously received. In FIG. 1, the same reference numerals as those in FIG. 2 represent the same functions and have been described above, so that the description here is omitted. As shown in FIG. 1, the method of the present invention uses a 5 ms frame (6.25) in the transmission and reception slots of each base station.
The base station 1 sets the # 1 transmission slot to the BC channel (broadcast channel indicating the start of system information).
The base station 2 allocates the # 2 transmission slot to the BC channel, the base station 3 allocates the # 3 transmission slot to the BC channel, and similarly similarly allocates the LCCH superframes of the adjacent base stations with a delay of one slot at a time. . The mobile station intermittently receives the incoming information channel P1 of each control channel of a plurality of receivable base stations (base station 1, base station 2, base station 3 in the figure).
At the time of calling, incoming information is simultaneously transmitted from each base station in the paging area pg1 and received by the mobile station through each incoming information channel P1 of the base station 1, the base station 2, and the base station 3 (FIG. 1 (e)). . The mobile station checks a plurality of incoming information (three in the figure), selects a connectable base station having a good radio wave condition, a free line, and connection. In the present invention, the LCCH interval value n = 2
0 (PHS public service), each base station is 100m
Since an LCCH superframe is transmitted at a rate of 1 slot per s, up to 80 base stations (with 4 slots) can exist without interfering with each other in the same area. Therefore, it is possible to continuously transmit a maximum of 80 times from each base station in a state where the slot timing of the incoming information channel to each incoming call group is synchronized. The mobile terminal broadcasts the timing of the arrival information channel group (P1 in FIG. 1 (a)) for the arrival group to which the mobile terminal belongs for a plurality of slots (three slots in FIG. 1).
By performing intermittent reception only, a standby operation can be performed for a plurality of base stations, and as a result, the incoming call rate can be improved without increasing power consumption. Although the above description has been made between the mobile terminal and the base station, the present invention is similarly applied to a home antenna of a home relay station which has recently been installed. When calling a base station from a mobile terminal, a base station having a vacant channel is selected from a plurality of base stations receiving a control channel, and a call is made on an uplink control channel. As described above, according to the present invention, the probability that the mobile station can receive the incoming information increases since the mobile station receives and monitors the incoming information channels from a plurality of base stations intermittently. Thus, there is no connection delay due to access retries, and it is possible to reliably and quickly connect to a base station having an empty line. In addition, in the state of waiting for an incoming call, it is only necessary to intermittently receive the incoming information channel, so that power consumption is reduced. As described above, according to the present invention, the following excellent effects are expected. (1) Since the mobile station simultaneously receives incoming information channels from a plurality of base stations, the probability that the received information channel can be received is increased even by temporary radio deterioration or interference. Lower the call loss rate. Further, by selecting a base station to be accessed at the time of an incoming call based on information such as a line use situation from each base station, useless access can be omitted and a reliable connection can be made. This is effective not only in improving the incoming call rate, but also in improving the wireless use efficiency and reducing the connection delay. (2) In the same manner as described above, the base station to be accessed at the time of origination from the mobile terminal is selected not only from the reception level of the control channel from the base station but also to the base station having an idle line, so that the calling rate and Improve wireless usage efficiency and satisfy user's feeling of use. (3) According to the present invention, the mobile terminal can receive control channels from a plurality of base stations in the area while maintaining the slot timing. Satisfy the feeling. In addition, in the state of waiting for an incoming call, it is only necessary to intermittently receive the incoming information channel, so that the power consumption is reduced and the life of the battery is extended.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing control channel signals of a mobile terminal and a base station in an incoming call waiting state in an outgoing / incoming call method of the present invention. FIG. 2 is a diagram illustrating control channel signals of a conventional mobile terminal and a base station in a call waiting state. FIG. 3 is a diagram showing a relationship between a base station and a mobile terminal in a paging area. [Description of Signs] 1 Base station 1-1 Service area 2 Base station 2-1 Service area 3 Base station 3-1 Service area 4 Base station 4-1 Service area 10 Center 11 Switch 12 Mobile terminal

Claims (1)

(57) Claims 1. A plurality of base stations synchronize a slot timing of a control channel within a paging area constituted by a plurality of base stations, and information on a superframe of the control channel is provided. In a call origination / termination system based on superframe synchronization that periodically intermittently transmits and communicates with a mobile terminal or a relay station, each base station in an adjacent service area shifts the slot timing of the superframe , No free channels
State in the incoming information channel on the superframe
The mobile terminal or the relay station is provided with a means for transmitting by including the information of the base station.
Means for intermittently receiving an incoming information channel on a frame and waiting for an incoming call, and calling one of the base stations
Is a group with an empty channel based on the incoming information channel
Superframe synchronization by incoming and outgoing call system, characterized in that a means for calling the earth station.