JP2009100319A - Synchronization method of radio base station with internet communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synchronization method of easily synchronizing the operation clock of a radio base station with an Internet communication method. <P>SOLUTION: A plurality of IP-adaptors (ADP) 13 are connected through an LAN 12 to an (IP-) private branch exchange (PBX) 11 with an Internet communication system, and a plurality of radio base stations (BS) 14 and one clock device (CLKE) 16 are connected to the IP-adaptor (ADP) 13. A clock device (CLKE) 16 generates a clock of 200 Hz by using incoming information 18 to be received every 1.2 second from a public PHS base station (CS) 17 existing in the shortest distance as a reference clock, and supplies the clock through the IP-adaptor (ADP) 13 to the radio base station (BS) 14. All the radio base stations (BS) 14 communicate with a simple mobile phone (PS) 15 by synchronizing a radio frame of 5 ms with the clock of 200 Hz. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio base station synchronization method capable of easily synchronizing the operation clock of a radio base station equipped with an Internet communication system.

  Conventionally, private wireless telephone systems of a type in which a plurality of wireless base stations are directly connected to a private branch exchange via wired lines are used in various places. As a typical example, PHS (Personal Handy-phone System / 1.9 GHz band) Some use a standard of a time division multiplexing (TDMA) digital mobile communication service using a frequency).

In such a communication system using TDMA, it is important to synchronize frame timing with adjacent base stations.
FIG. 9 is a diagram showing a PHS system in which a plurality of wireless base stations (BS) are directly connected to a conventional private branch exchange (PBX) through a wired line.

In FIG. 9, a private branch exchange (PBX) 1 and a wireless base station (BS) 2 are connected by a wired time division multiplexing digital line 3.
In this configuration, the private branch exchange (PBX) 1 determines the timing of the radio frame transmitted from the radio base station (BS) 2 in addition to voice information and control information to the radio base station (BS) 2. Is transferred. The simplified mobile phone (PS) 4 shown in the figure is a PHS slave unit.

FIG. 10 is a diagram showing a configuration of a radio frame communicated between the radio base station (BS) 2 and the simplified mobile phone (PS) 4 shown in FIG.
One radio frame 5 includes four transmission slots (T1, T2, T3, T4) that can be transmitted from the radio base station (BS) 2 and four reception slots (R1, R2, R3, R4) constitute a set.

  The transmission slot T1 corresponds to the reception slot R1, the transmission slot T2 corresponds to the reception slot R2, the transmission slot T3 corresponds to the reception slot R3, and the transmission slot T4 corresponds to the reception slot R4. Yes.

  For example, if one radio base station (BS) 2 selects the transmission slot T2 as a transmission slot, the response from the simplified mobile phone (PS) 4 to the signal transmitted in the transmission slot T2 is It is received by the station (BS) 2 at the timing of the reception slot R2.

Note that the time zone of one radio frame 5 is determined to be 5 ms (milliseconds). Accordingly, there are 200 radio frames 5 per second.
That is, in this system, communication is performed by a time division multiplexing method in which one second is divided into 200 frames and the transmission / reception band is divided into four sets in each frame.

10 is synchronized with the reference timing 6 received from the private branch exchange (PBX) 1.
As a result, the mobile phone (PS) 4 that is moving, regardless of which radio base station (BS) 2 takes over the call relay, the control signal transmitted in the radio frame 5 is transmitted immediately before. Since it is synchronized with the radio frame 5 used by the radio base station (BS) 2, no confusion or interference occurs in communication.

By the way, in recent years, a communication method based on the Internet Protocol (IP) has been used as a communication method.
FIG. 11 is a diagram showing a conventional PHS system configured by a local area network (LAN) equipped with an Internet protocol (IP).

  In FIG. 11, an IP adapter (IP-ADP) 7 (7m, 7s) performs communication between the IP private branch exchange (IP-PBX) 9 and the wireless base station (BS) 2 performed via the LAN 8. It is an adapter to make it.

  A function corresponding to the function of the IP adapter (IP-ADP) 7 exists in the IP-private branch exchange (IP-PBX) 9. The relationship between the IP adapter (IP-ADP) 7 and the radio base station (BS) 2 is the same as the relationship between the private branch exchange (PBX) 1 and the radio base station (BS) 2 in FIG.

Note that the Internet protocol is originally used to check communication between addresses, and there is no concept of performing communication between each other in time synchronization.
Therefore, in the case of a conventional PHS system with an IP mounting LAN, an IP private branch exchange (IP-PBX) 9 transmits a synchronization clock via the LAN, and a radio frame in which one frame is repeated at intervals of 5 ms. It is difficult to synchronize.

For this reason, in order to synchronize between the plurality of radio base stations (BS) 2, it is necessary to connect the plurality of IP adapters (IP-ADP) 7 with the clock line 10.
Therefore, as shown in FIG. 11, one of the plurality of IP adapters (IP-ADP) 7 is a master IP adapter (IP-ADP) 7m that generates a reference clock, and the rest are slaves. As a (slave) IP adapter (IP-ADP) 7s, these are connected by a clock line 10 so that each slave operates in synchronization with a master clock.

  By the way, since IP adapters constitute a LAN, they are often installed apart from each other. In addition, as described above, in the LAN configuration equipped with the IP system, the clock signal cannot be transmitted through the LAN, so the clock line needs to be wired separately from the LAN wiring.

However, when a plurality of IP adapters are installed apart from each other, there are cases where the plurality of IP adapters cannot be connected with the same clock line.
For example, if the distance is too far, there will be a problem in terms of man-hours, and if there are physical obstacles such as trees or buildings in the middle, there will be problems in implementation. In such a case, a plurality of IP adapters cannot be connected with the same clock line.

  Further, when the IP adapters are grouped together in groups that can be connected by the same clock line and the master IP adapter is provided for each group, it becomes impossible to operate all the IP adapters with the same master clock.

Then, radio waves of radio base stations with different clock systems in adjacent groups interfere with each other, causing a problem that the simplified mobile phone cannot be used normally.
In view of the above-described conventional situation, an object of the present invention is to provide a synchronization method for easily synchronizing an operation clock of a radio base station equipped with an Internet communication system.

  First, the synchronization method of the wireless base station equipped with the Internet communication method in the first embodiment is the same as the synchronization method of the wireless base station equipped with the Internet communication method in the private communication system. A plurality of wireless base stations equipped with a communication method, and an IP (Internet Protocol) communication network to which the private branch exchange is connected and the plurality of wireless base stations, the private branch exchange and the wireless base station An adapter that converts communication between the wireless communication system and the Internet communication system, and a clock device connected to the adapter, the clock device receiving incoming information transmitted from a public radiotelephone base station as a low-frequency reference Reference clock receiving means for receiving as a clock, and the reference received by the reference clock receiving means A frame clock generation unit that generates a frame clock having a frequency that conforms to the period of the reference clock of the public PHS base station and matches the period of the radio frame based on the reception timing of the lock, and the frame clock generation unit Synchronous clock supply means for supplying the frame clock to the radio base station via the adapter as a synchronous clock for a radio frame for operating the radio base station.

  Next, the synchronization method of the wireless communication base station equipped with the Internet communication method in the second embodiment includes a private branch exchange equipped with the Internet communication method, a plurality of wireless base stations equipped with the Internet communication method, and the private branch exchange. A plurality of adapters connected between a connected IP (Internet Protocol) communication network and the plurality of wireless base stations to convert communication between the private branch exchange and the wireless base station into an Internet communication system; , A wireless base station synchronization method equipped with an Internet communication system in a private communication system having a plurality of clock devices connected to each of the predetermined groups of the plurality of adapters, one of the clock devices being a master A low-frequency reference clock that conforms to the transmission cycle of incoming information of public radiotelephone base stations. In addition, the radio base station that generates a frame clock for operating the radio base station and is connected to the clock device that is the master via the adapter is connected to the reference clock from the clock device that is the master. The frame clock is supplied and the reference clock is transmitted to the outside, and the clock device other than the master receives the reference clock transmitted from the radio base station as a slave and receives the received reference clock. A frame clock synchronized with the reference clock is generated, and the frame clock and the reference clock are supplied to the radio base station connected to the apparatus through the adapter, and the radio base station The clock is configured to be wirelessly supplied to the clock device that is another slave. .

  In the second embodiment, for example, the clock device as the master has ID setting means for setting a private communication system ID, and uses the private communication system ID set by the ID setting means. The reference clock and the frame clock are supplied to the radio base station connected to the own device, and the clock device as the slave includes an ID setting means for setting the private communication system ID, and the ID setting means. And a search means for searching for the radio base station of the set private communication system ID.

  In the first or second embodiment, the clock device associates the reception timing of the reference clock with a control slot transmitted by the radio base station, and as a control slot transmitted by the radio base station. A specific control slot is configured to be assigned with priority.

In this case, the specific control slot is preferably the first transmission slot of the four transmission slots of the radio frame, for example.

  According to each embodiment described below, it is possible to realize a synchronization method for easily synchronizing operation clocks of radio base stations equipped with the Internet communication system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the following description of each embodiment, for example, the term “private” is used as a private branch exchange, and this “private” is a term for distinguishing from “office” (public, commercial). is there.

  For example, an IP-private branch exchange (PBX) 11 (to be described later) is installed in Tokyo as a wide area private communication system, and an IP-adapter (ADP) 13, a radio base station (BS) 14, and a clock device (CLKE16) to be described later. ) In Osaka.

  Then, the IP-private branch exchange (PBX) 11 in Tokyo and the IP-adapter (ADP) 13 in Osaka are connected by a transmission path via the Internet instead of the LAN described in the embodiment, and the same method as in the embodiment Thus, the Osaka radio base station (BS) 14 may be synchronized.

  Also in this case, the IP-private branch exchange (PBX) 11 installed in Tokyo is a “private branch exchange”, and the Osaka radio base station (BS) 14 is a “private radio base station”.

FIG. 1 is a diagram illustrating a communication system that employs a synchronization method for a radio base station equipped with the Internet communication method according to the first embodiment.
The communication system of this example shown in FIG. 1 is connected to a private branch exchange (indicated by “PBX” in the figure) 11 equipped with an Internet communication system, and this IP-private branch exchange (PBX) 11. LAN 12, a plurality of IP-adaptors (indicated by “ADP”) 13 connected to the LAN 12, and a plurality of wireless base stations (in the figure “ 14) (indicated by “BS”).

  A clock device (indicated by “CLKE” in the figure) 16 is connected to the plurality of IP-adapter (ADP) 13 by wire. The clock device (CLKE) 16 receives incoming call information (“PCH” in FIG. 7 described later) transmitted from the public PHS base station (indicated by “CS” in the figure) 17 within the shortest distance from the clock device 16 every 1.2 seconds. ) 18 is received.

  In addition, the radio base station (BS) 14 synchronizes with a reference clock supplied from the clock device (CLKE) 16 via the IP-adapter (ADP) 13, and is a simple mobile phone (in the figure, “PS”). Communicate with 15).

  In the configuration of this example, the main configuration different from FIG. 11 is that the clock for synchronization is not supplied from the master IP-adapter but from the clock device (CLKE) 16, and the clock device (CLKE) 16 does not generate a clock by itself, but generates a reference clock based on incoming call information (PCH) 18 transmitted from public PHS base station (CS) 17.

  The IP-adapter (ADP) 13, the radio base station (BS) 14, and the simple mobile phone (PS) 15 after the reference clock is supplied from the clock device (CLKE) 16 to the IP-adapter (ADP) 13 The operation is the same as that of the conventional IP adapter (IP-ADP) 7, wireless base station (BS) 2, and simplified mobile phone (PS) 4 shown in FIG. 11.

  FIG. 2 is a block diagram illustrating a configuration example of the clock device (CLKE) 16 of the present example. As shown in the figure, the clock device (CLKE) 16 includes a radio module (indicated by “RF” in the figure, the same applies hereinafter) 21, a time division multiplexing control unit (TDMA) 22, a control unit (CTL) 23, and clock pull-in. A circuit (PLL) 24, a timing generator (TG) 25, and a power supply device (PWR) 26 are provided.

The control unit (CTL) 23 is connected to a memory device (M) 27, a display device (LCD) 28, and an input key operation unit (KEY) 29.
The radio module (RF) 21 receives incoming call information (PCH) 18 transmitted from the public PHS base station (CS) 17 located at the shortest distance as a reference clock.

  The time division multiplexing control unit (TDMA) 22 is a slot on a radio frame (see radio frame 5 in FIG. 10) (see transmission slots T1, T2, T3, T4 and reception slots R1, R2, R3, R4 in FIG. 10). Are assembled and disassembled, and information received via the wireless module (RF) 21 is notified to the control unit (CTL) 23.

  The clock pull-in circuit (PLL) 24 generates a clock dependent on the output signal of the radio module (RF) 21 generated by the received radio wave of the incoming call information (PCH) 18 received during standby.

  The timing generator (TG) 25 uses the clock generated by the clock pull-in circuit (PLL) 24 as a timing signal used by the radio base station (BS) 14 and supplies the timing signal to the IP-adapter (ADP) 13. .

  The display device (LCD) 28 displays information of the control unit (CTL) 23. The input key operation unit (KEY) 29 inputs information to the control unit (CTL) 23. A power supply unit (PWR) 26 supplies necessary power to each unit.

The memory device (M) 27, the display device (LCD) 28, and the input key operation unit (KEY) 29 are mainly used in a second embodiment to be described later.
FIG. 3 is a flowchart for explaining the processing operation of the control unit (CTL) 23 of the clock device (CLKE) 16.

  In FIG. 3, when the control unit (CTL) 23 is activated, the control unit (CTL) 23 searches for a public PHS base station (CS) 17 having a preset operator ID (step S1). This search process is a process for finding a public PHS base station (CS) 17 that is closest and has the highest radio wave level.

  In Japan (Japan), there are initially three public PHS service providers, and therefore there are three types of business IDs. Public PHS telephones have one of the three types of business IDs. A person ID was set.

  When the public PHS telephone is used, the public PHS base station (CS) 17 of the set operator ID is searched, and the ID of the public PHS telephone of the own machine is set as the public PHS base station (CS). 17 is notified to perform location registration processing and enters a standby state.

However, at present, there is only one public PHS service provider, and therefore, the operator ID preset in the clock device (CLKE) 16 is only one type with no room for selection. In any case, in a normal area, the public PHS base station (CS) 17 has almost 50
It is installed everywhere at intervals of 0m.

  After starting the above search, it is determined whether or not the signal of the public PHS base station (CS) 17 corresponding to the provider ID has been received (step S2), and if not received, it waits until it can be received (S2). N).

  Then, when reception is possible (S2 is Y), that is, when the standby public PHS base station (CS) 17 is determined, in a normal public PHS telephone, the location registration process is performed at the position X in the flowchart of FIG. However, since the clock device (CLKE) 16 of this example only needs a function of receiving the incoming call information (PCH) 18, it skips location registration processing and directly transitions to a standby state (step S3). .

  The standby operation in step S3 is a process of receiving incoming call information (PCH) 18 sent from the public PHS base station (CS) 17 every 1.2 seconds, although not particularly shown.

  4 and 5 are diagrams for explaining processing in which a clock for synchronization is generated by the clock pull-in circuit (PLL) 24 based on the incoming call information (PCH) 18 received every 1.2 seconds as described above. It is.

  As shown in FIG. 4, the clock pull-in circuit (PLL) 24 includes a correction unit 31 and a clock generation unit 32. The incoming call information (PCH) 18 received by the wireless module (RF) 21 is output to the external timing generator (TG) 25 and the internal correction unit 31 as a timing signal every 1.2 seconds.

The clock generation unit 32 is a transmitter that generates a clock having a frequency of 200 Hz, and outputs the clock to the external timing generation unit (TG) 25 and the internal correction unit 31.
As shown in FIG. 5A, the correction unit 31 monitors incoming information (PCH) 18 input as a timing signal every 1.2 seconds from the radio module (RF) 21, and also generates a clock generation unit 32. The pulse number P of the 200 Hz clock input from is counted.

  Then, as shown in FIG. 5 (b), when the number of clock pulses P counted in 1.2 seconds exceeds 240P for 1.2 seconds, this clock is transmitted to the public PHS base station (CS ) Since the clock period is faster than 17, the number of pulses ΔP exceeding 240P is fed back to the correction unit 31 as a correction value “−ΔP”.

  Further, as shown in FIG. 5 (c), the correction unit 31 determines that this clock is the public PHS when the number of clock pulses P counted for 1.2 seconds is less than 240P for 1.2 seconds. Since it is later than the clock cycle of the base station (CS) 17, the number of pulses ΔP that is less than 240P is fed back to the correction unit 31 as a correction value “+ ΔP”.

  With the above feedback, the clock output from the clock generator 32 to the timing generator (TG) 25 is adjusted to a clock having a correct frequency of 200 Hz that correctly conforms to the clock cycle of the public PHS base station (CS) 17.

  This correctly adjusted clock of 200 Hz is a clock at which one frequency is 5 ms (milliseconds), and is a clock required for the radio base station (BS) 14 to use a radio frame of 5 ms.

The timing generator (TG) 25 uses this correctly adjusted 200 Hz clock as the I
The data is supplied to the radio base station (BS) 14 through the P-adapter (ADP) 13.
As described above, according to the first embodiment, the standby function generally provided in a public PHS telephone is used for the clock device (CLKE) 16, and the reception timing of the incoming call information (PCH) 18 is determined from the public PHS base. A clock period of 1.2 seconds of the station (CS) 17 is extracted, and on the basis of this clock period, a clock having a frequency of 5 ms for operating the radio base station (BS) 14 equipped with the Internet communication system (IP) Is generated.

  Thus, since the clock for operating the radio base station (BS) 14 is generated using the clock period of the public PHS base station (CS) 17, all the radio base stations (BS) 14 equipped with IP are provided. The operation clocks can be easily synchronized.

Therefore, there is no fear that even radio base stations (BS) 14 may interfere with radio waves and interfere with a call with the simplified mobile phone (PS) 15.
In addition, according to the present embodiment, a plurality of IP adapters (IP-ADP) 13 are provided by installing an appropriate number of clock devices (CLKE) 16 according to the installation status of IP-adapter (ADP) 13. Even if all the IP adapters (IP-ADP) 13 are connected by a cloak line, all the wireless base stations (BS) 14 equipped with IP can be connected to the public PHS base station (CS). It can be synchronized with 17 clocks.

  This not only facilitates the construction of the Internet communication system, but also avoids the occurrence of problems due to interference between radio waves of the radio base station (BS) 15 over time. become.

  By the way, when the communication system of the above-mentioned Internet communication system is constructed in an area or place where the public PHS service is not reachable, the clock of the public PHS base station (CS) 17 cannot be used.

  However, according to another method of the present invention, it has been described above even in a region or place where the public PHS service is not reachable, and in a place where it is difficult to route the same clock line to all IP-adapter (ADP). A similar Internet communication system communication system can be constructed. Hereinafter, this will be described as a second embodiment.

FIG. 6 is a diagram illustrating a communication system that employs a synchronization method of a radio base station equipped with the Internet communication method according to the second embodiment.
In FIG. 6, IP-adapter (ADP) 13 is grouped in close proximity, and one group is grouped into one clock device (CLKE-m) 16 m or one clock device (CLKE-s) 16 s. It is connected.

  The clock device (CLKE-m) 16m is a master clock device, and there is only one clock device in the communication system. The master clock device (CLKE-m) 16m is a built-in high-precision clock generator 33, and a 200 Hz frame clock used by the IP-adapter (ADP) 13 to operate the radio base station (BS) 14. The frame clock is supplied to the IP-adapter (ADP) 13.

  At the same time, the clock device (CLKE-m) 16m generates a low-frequency reference clock signal every 1.2 seconds in accordance with the reference clock signal transmitted from the public PHS base station, and uses this reference clock as the IP clock. Supply to adapter (ADP) 13

Then, a radio base station (BS) 14 connected to these IP-adapter (ADP) 13
Is supplied with a reference clock and a frame clock from the IP-adapter (ADP) 13, communicates with the simplified mobile phone (PS) 15 using a desired transmission / reception slot of a radio frame based on the frame clock, and 1 .Send a reference clock with a period of 2 seconds to the outside.

  The clock device (CLKE-s) 16s other than the master is a slave clock device. The slave clock device (CLKE-s) 16s receives a reference clock having a period of 1.2 seconds transmitted from the radio base station (BS) 14, and a frame of 200 Hz synchronized with the received reference clock. A clock is generated in the device itself.

Then, the generated frame clock and the received reference clock are supplied to the radio base station (BS) 14 connected to the own apparatus via the IP-adapter (ADP) 13.
The radio base station (BS) 14 connected to the slave clock device (CLKE-s) 16s via the IP-adapter (ADP) 13 uses a desired transmission / reception slot of the radio frame based on the frame clock. In addition to communicating with the simplified mobile phone (PS) 15, the reference clock is transmitted to the outside, and the reference clock is wirelessly supplied to the clock device (CLKE-s) 16s which is another slave.

In this way, the wireless supply of the reference clock is sequentially repeated between the groups of the adjacent clock devices (CLKE-s) 16s, and the wireless supply range of the reference clock is sequentially expanded.
Since the operation of transmitting and receiving the reference clock is based on the PHS system shown in the first embodiment, a private communication system ID is used instead of the communication system ID of the public PHS service provider. Necessary.

  This self-employed communication system ID is obtained by the display device (LCD) 28 and the input key operation unit (KEY) shown in FIG. 2 in the master clock device (CLKE-m) 16m. 29 is used and is arbitrarily set.

  The set private communication system ID is stored in the memory device (M) 27 by the control unit (CTL) 23. The private communication system ID stored (set) in the memory device (M) 27 is supplied to the radio base station (BS) 14 via the IP-adapter (ADP) 13 together with the reference clock and frame clock described above. .

  The same private communication system ID as above is set in the clock device (CLKE-s) 16s as a slave in the same manner as described above. The control unit of the slave clock device (CLKE-s) 16s reads the private communication system ID stored (set) in the memory device (M) 27 and has the same ID as the private communication system ID. The base station (BS) 14 is searched to enter a reference clock standby state.

  The processing of the slave clock device (CLKE-s) 16s is processing for searching for a private communication system ID in place of the operator ID in step S1 of the flowchart shown in FIG.

  That is, in the second embodiment shown in FIG. 6, when the control unit (CTL) 23 of the clock device (CLKE-s) 16s as a slave is activated, the control unit (CTL) 23 is set in advance. The wireless base station (BS) 14 having the highest radio wave level that is closest to the transmitting wireless signal of the private communication system ID is searched for, and the wireless base station (BS) 14 is awaited. It is determined as a radio base station (BS) 14. Then, a standby state for receiving a reference clock from the radio base station (BS) 14 is entered.

As described above, according to the present embodiment, since synchronization can be established within the private communication system, all wireless base stations equipped with IP in the entire communication system (even in places where public PHS radio waves cannot be received) BS) 14 frame clock can be easily synchronized.

  By the way, the radio frame used by the radio base station (BS) 14 includes four transmission slots (also referred to as downlink slots) T1, T2, T3, and T4 in which one radio frame can be transmitted from the radio base station. As described above, four reception slots (also referred to as uplink slots) R1, R2, R3, and R4 that can be received by the station are configured as one set.

In addition, as described above, the time zone of one radio frame is determined to be 5 ms (milliseconds), and therefore 240 radio frames can exist in 1.2 seconds.
Each radio base station (BS) 14 determines the start timing of radio frames having 240 frames with reference to the reference clock. Which set of slots is used as a control slot among four slots (T1 and R1, T2 and R2, T3 and R3, T4 and R4), one set above and below the radio frame used at the determined start timing. The base clock here is a 1.2 second period transmitted by the public PHS base station (CS) 17 in the first embodiment. In the second embodiment, the master clock device (CLKE-m) 16m outputs and the radio base station (BS) 14 transmits to the outside in the second embodiment. A reference clock with a period of seconds.

  As described in the first and second embodiments, the clock of the radio frame is synchronized based on the reference clock. However, the radio frame itself is not synchronized. That is, only one of the four slots in the upper and lower sets constituting the radio frame is synchronized.

  Therefore, if the slot used as a control slot differs between different radio base stations (BS) 14 and the start timing of the first slot T1 of the radio frame is different, a transmission slot of a certain radio base station (BS) 14 There is a possibility that the reception slots of other wireless base stations (BS) 14 interfere with each other.

For example, it is assumed that a certain radio base station (BS) 14 uses a slot T1 / R1 and another radio base station (BS) 14 uses an empty slot T2 / R2.
Then, it is assumed that the start timing of the start slot T1 of the radio frame of another radio base station (BS) 14 is delayed by 3 slots from the start timing of the start slot T1 of the radio frame of a certain radio base station (BS) 14. .

  Then, the uplink control signal using the slot R1 corresponding to the downlink control signal using the slot T1 of a certain radio base station (BS) 14 becomes the downlink control using the slot T2 of another radio base station (BS) 14. Interfering with the signal.

  At the next time point, the uplink control signal using the slot R2 corresponding to the downlink control signal using the slot T2 of another radio base station (BS) 14 is transmitted to the slot T1 of a certain radio base station (BS) 14. Interference with the downlink control signal using the.

  That is, a transmission control slot of a certain radio base station (BS) 14 overlaps with a reception control slot of another radio base station (BS) 14, and the control slot that the radio base station (BS) 14 transmits periodically An event occurs in which the connection of the simple mobile phone (PS) fails.

In the third embodiment, a synchronization method that does not cause interference of control signals as described above will be described below.
FIG. 7 is a diagram for explaining an embodiment for avoiding an uplink / downlink collision of a control channel (control slot). Note that the processing shown in the figure is processing performed by the clock device (CLKE) 16.

  As shown in FIG. 7, the clock device (CLKE) 16 receives the timing B at which the incoming call information (PCH) 18 is received at intervals of 1.2 seconds and the timing corresponding to the start of the radio frame of the radio base station (BS) 14. C is synchronized, and when the downlink control slot to be used at this timing C is determined, the slot T1 which is the first slot of the radio frame is preferentially assigned.

FIGS. 8A, 8B, 8C, and 8D are diagrams for explaining the reason why control signal interference does not occur by preferentially assigning the slot T1 as the use start slot.
FIG. 8A shows the original radio frame shown in the lower part of FIG. 7 determined by the clock device (CLKE) 16. FIGS. 8B, 8C, and 8D are diagrams showing a state in which the radio frame used by the radio base station (BS) 14 is sequentially shifted from one slot to three slots for some reason.

  If the downlink control slot transmitted by the radio base station (BS) is the slot T1, the slot T1 is shifted by any number of slots (returns to the original after shifting by 4 slots), the clock device (CLKE) 16 It falls within the range of downlink control slots Tl to T4 of the determined original radio frame.

  Therefore, in a normal use state, the downlink control slot T1 transmitted by the radio base station (BS) 14 is the uplink control slot R1 of another radio base station (BS) 14 that has received the incoming call information (PCH) 18. It does not overlap with ~ R4.

  Therefore, the transmission control slot of the radio base station (BS) 14 overlaps with the reception control slot of the other radio base station (BS) 14, and the simplified control slot is transmitted by the radio base station (BS) 14 periodically. It is possible to avoid an event such as failure to connect a mobile phone (PS).

  In the above description of the embodiment, a private communication system in which the IP-private branch exchange (PBX) 11 and the IP-adapter (ADP) 13 are connected by a LAN has been described. However, the private communication system is not limited to connection by a LAN. Absent.

  For example, a connection form such as LAN-WAN-LAN may be used. Furthermore, as described at the beginning of the description of the invention, a wide-area private communication system having a connection form using a transmission path via the Internet may be constructed.

  In the above description of the embodiment, the IP-adapter (ADP) 13, the radio base station (BS) 14, and the clock device (CLKE) 16 are described as separate devices, but two or all of these devices are described. Even if they are mounted on the same device, the effect of the present invention does not change.

It is a figure which shows the communication system which employ | adopted the synchronization method of the radio | wireless base station mounted with the internet communication system in 1st Embodiment. It is a block diagram which shows the structural example of the clock apparatus (CLKE) of the communication system in 1st Embodiment. It is a flowchart explaining the processing operation of the control part (CTL) of the clock apparatus (CLKE) of the communication system in 1st Embodiment. It is a figure which shows the structure of the clock drawing circuit (PLL) of the clock apparatus (CLKE) which produces | generates the clock for a synchronization in 1st Embodiment. It is a figure explaining the specific process of the feedback control in the clock generation process for a synchronization of the clock acquisition circuit (PLL) in 1st Embodiment. It is a figure which shows the communication system which employ | adopted the synchronization method of the radio | wireless base station mounted with the internet communication system in 2nd Embodiment. It is a figure explaining the Example which avoids the uplink / downlink collision of the control channel (control slot) in 3rd Embodiment. (a), (b), (c), (d) is a figure explaining the reason why the interference of the control signal does not occur by preferentially assigning the slot T1 as the use start slot in the third embodiment. . It is a figure which shows the PHS system of the format which connected the some wireless base station (BS) to the conventional private branch exchange (PBX) with the wired line directly. It is a figure which shows the structure of the radio | wireless frame communicated between a radio base station (BS) and a simple mobile phone (PS). It is a figure which shows the PHS system comprised by the local area network (LAN) carrying the conventional internet communication system (internet protocol: IP).

Explanation of symbols

1 Private branch exchange (PBX)
2 Radio base stations (BS)
3 Time division multiplexing wired digital line 4 Simple mobile phone (PS)
5 Radio frame 6 Reference timing 7 (7m, 7s) IP adapter (IP-ADP)
8 LAN (local area network)
9 IP Private Branch Exchange (IP-PBX)
10 Clock line 11 IP-Private Branch Exchange (PBX)
12 LAN
13 IP-Adapter (ADP)
14 Wireless base stations (BS)
15 Simple mobile phone (PS)
16 Clock device (CLKE)
17 Public PHS Base Station (CS)
18 Incoming call information (PCH)
21 Wireless module (RF)
22 Time Division Multiplexing Control Unit (TDMA)
23 Control unit (CTL)
24 Clock pull-in circuit (PLL)
25 Timing generator (TG)
26 Power supply (PWR)
27 Memory device (M)
28 Display (LCD)
29 Input key operation section (KEY)
31 Correction unit 32 Clock generation unit

Claims (5)

In the synchronization method of the radio base station equipped with the Internet communication method in the private communication system,
A private branch exchange equipped with an Internet communication method,
A plurality of wireless base stations equipped with Internet communication methods;
Connected between an IP (Internet Protocol) communication network to which the private branch exchange is connected and the plurality of wireless base stations, and converts communication between the private branch exchange and the wireless base station into an Internet communication system. An adapter,
A clock device connected to the adapter;
Have
The clock device includes:
A reference clock receiving means for receiving as a reference clock for incoming information transmitted from a public radiotelephone base station;
Frame clock generation means for generating a frame clock having a frequency that conforms to the period of the reference clock of the public radiotelephone base station and matches the period of the radio frame based on the reception timing of the reference clock received by the reference clock reception means When,
Synchronization clock supply means for supplying the frame clock generated by the frame clock generation means to the radio base station via the adapter as a synchronization clock of a radio frame for operating the radio base station,
A synchronization method of a radio base station equipped with an Internet communication system. A private branch exchange equipped with an Internet communication method,
A plurality of wireless base stations equipped with Internet communication methods;
Connected between an IP (Internet Protocol) communication network to which the private branch exchange is connected and the plurality of wireless base stations, and converts communication between the private branch exchange and the wireless base station into an Internet communication system. Multiple adapters,
In a synchronization method of a radio base station equipped with an Internet communication method in a private communication system having
A plurality of clock devices respectively connected to a predetermined group of the plurality of adapters;
One of the clock devices, as a master, generates a low-frequency reference clock that complies with the transmission cycle of incoming information of a public radiotelephone base station, and generates a frame clock for operating the radio base station,
The radio base station connected to the clock device that is the master via the adapter is supplied with the reference clock and the frame clock from the clock device that is the master, and the reference clock is externally provided. Outgoing,
The clock device other than the master receives the reference clock transmitted from the radio base station as a slave, generates a frame clock synchronized with the received reference clock, and generates the frame clock and the reference clock. To the wireless base station connected to its own device through the adapter,
The wireless base station wirelessly supplies the supplied reference clock to the clock device which is another slave.
A synchronization method of a radio base station equipped with an Internet communication system. The clock device that is the master has ID setting means for setting a private communication system ID, and the private communication system ID set by the ID setting device is stored in the self device together with the reference clock and the frame clock. Supplying the connected radio base station;
The clock device as the slave has ID setting means for setting the private communication system ID, and search means for searching for the radio base station of the private communication system ID set by the ID setting means. ,
The method of synchronizing a radio base station equipped with the Internet communication system according to claim 2. The clock device associates the reception timing of the reference clock with a control slot transmitted by the radio base station, and
A specific control slot is preferentially assigned as a control slot transmitted by the radio base station,
The method of synchronizing a radio base station equipped with the Internet communication system according to claim 1 or 2.   5. The synchronization method of a radio base station equipped with the Internet communication system according to claim 4, wherein the specific control slot is a first transmission slot of four transmission slots of a radio frame.

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