HK1017561A - Radio pbx for personal communication system - Google Patents

Description

Wireless private branch exchange for personal communication system

The present invention relates to mobile wireless communication systems and, more particularly, to the structure of a radio PBX (private branch exchange) apparatus including control trunks, local line trunks, service trunks, repeater trunks and incoming and outgoing line trunks, which includes at least one set of digital transmitters and receivers for receiving and detecting new RF signals in RF signals through the interconnection between the receivers and the transmitters in FDMA (frequency division multiple access) or cascaded trunk mode, TDMA (time division multiple access) trunk mode or CDMA (code division multiple access) trunk mode using baseband ICs, and relates to the field of wireless PBX apparatuses in general, which include several types of trunk circuits for providing services to portable subscriber units within a service area through the connection of these trunk circuits. The modulated RF signal is also coupled to an indoor antenna (or distributed antenna) for communication with the subscriber unit.

The purpose of this wireless PBX (private branch exchange) is to reduce system cost and increase traffic capacity by securing channel use efficiency.

In the prior art, microcell systems are composed of a digital PBX and a separate base station, wherein the PBX and the base station are connected by an indoor telephone cable, and the base station forms a plurality of microcell service areas.

Problems may arise when the above-described microcell system is applied to be installed in an actual personal communication system because the traffic capacity of individual base stations is very limited, a large number of base stations must be installed within a service area, and severe interference between the base stations sometimes prevents basic operation of subscriber units, and this increases the overall system cost and loses channel use efficiency.

The present invention provides a new and improved apparatus for a wireless PBX in which the transceivers themselves have switching capabilities to interconnect calls between subscriber units or between a subscriber unit and an external base station or between a subscriber unit and a telephone line. Since the transceivers are concentrated at a central location and since a suitable number of indoor antennas are connected by coaxial cables, the interface units and indoor telephone cables connected between the respective individual base stations and the PBX can be completely eliminated, and not only the equipment cost but also the installation cost can be reduced.

In summary, the wireless PBX is installed at a central location, and an appropriate number of indoor antennas are installed within the service area through coaxial cables. Several types of trunks are structured to implement the wireless PBX by being structured to employ a plurality of the transceivers. The existing CATV (cable television) cable can be used as the coaxial cable of the present invention without any modification.

In one embodiment, a group of transceivers can be configured as control trunks, trunk lines, local line trunks, service trunks, or inbound and outbound trunks installed within the local wireless PBX.

In a second embodiment, incoming and outgoing trunks are coupled to the local wireless PBX through an open air or coaxial cable network or CATV cable network to ensure higher channel utilization efficiency.

In a third embodiment, the present wireless PBX can provide an economical seamless network for data communications.

The invention is pointed out with particularity in the appended claims. The above and further advantages of the invention will be better understood from the following detailed description of an illustrative embodiment thereof, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of a system including distributed antennas constructed in accordance with the present invention;

FIG. 2 is a block diagram of another system including distributed antennas constructed in accordance with the present invention;

figure 3 is a block diagram of a wireless PBX including control trunks and/or trunk lines constructed in accordance with the present invention;

figure 4 is another block diagram of a wireless PBX constructed in accordance with the present invention and including control trunks and/or trunk lines;

figure 5 is another block diagram of a wireless PBX including local line trunks constructed in accordance with the present invention;

figure 6 is another block diagram of a wireless PBX including control trunks and/or trunk lines, local line trunks, and incoming and outgoing trunks constructed in accordance with the present invention;

figure 7 is another system block diagram of a wireless PBX coupled to incoming and outgoing trunks via open air propagation and constructed in accordance with the present invention;

figure 8 is another system block diagram of a wireless PBX coupled to incoming and outgoing trunks via an existing CATV cable network constructed in accordance with the present invention;

figure 9 is another system block diagram of a wireless PBX coupled to incoming and outgoing trunks via a coaxial cable network to provide a seamless data network constructed in accordance with the present invention;

figure 10 is another system block diagram of a wireless PBX including control trunks and/or trunk lines constructed in accordance with the present invention;

figure 11 is a timing diagram between the incoming and outgoing trunks and the coupled wireless PBX constructed in accordance with the present invention;

figure 12 is another timing diagram between the incoming and outgoing trunks and the coupled wireless PBX constructed in accordance with the present invention;

fig. 13 is a block diagram of a conventional duplex Radio Frequency (RF) relay system.

Referring to fig. 13, a stand-alone base station 101 is shown coming to a microcell coverage area and connected to a PBX 150 via a line interface unit 114 and indoor telephone cables 106a and 106 b. In the base station 101, the digital transceiver 110 is coupled to the antenna 102 via an antenna terminal 139 for transmitting RF signals to and receiving RF signals from the subscriber units 103a and/or 103b, 103a and/or 103 b. The PBX 150 is further connected to a telephone line 152 via an MDF (main distribution frame) 151.

The transceiver 110 includes at least one transmitter 111, a receiver 112, a baseband IC 121, a synthesizer 122, a controller 113, an antenna switch 140, and ADPCM (adaptive differential pulse code modulation) codecs 141a and 141 b. In this scenario, there is no cost-effectiveness and very limited traffic, even multiple independent base stations connected to the PBX by indoor telephone cables, and the inefficiency and limited traffic capacity as long as the base stations form individual microcell coverage areas and the coverage areas do not overlap each other to serve the indoor coverage areas.

Referring to fig. 1, RF signals from a transmitter 111 of a wireless PBX100 are coupled to a distributed antenna 1a on a terminal 21a and to a distributed antenna 1b on a terminal 21b by coaxial cables 31a and 31 b. The receiver 112 of the wireless PBX is coupled to the distributed antenna 1a on the terminal 22a and to the distributed antenna 1b on the terminal 22b by coaxial cables 32a and 32 b. The transmitter 111 and receiver 112 are controlled by a controller 113 and coupled to a telephone line 152 through a line interface unit 114 and an MDF 151. In the distributed antennas 1a and 1b, downlink RF signals are amplified by downlink amplifiers 2a and 2b and coupled to dividers (dividers) 4a and 4b, which are then coupled to one of the internal antenna elements 7a and 7b by combiners 6a and 6b, and which are radiated from the internal antenna elements 7a and 7b and coupled to subscriber units 103a and/or 103 b. The other direction of the dividers 4a and 4b is coupled to terminals 23a and 23b for connecting the next stage of the distributed antenna 1a or 1 b. Since the amplification gains of the amplifiers 2a and 2b are adjusted to match the total loss of the coaxial cables 31a or 31b, the dividers 4a and 4b, and the combiners 6a or 6b, the power radiated from the antenna elements 7a or 7b and the power output from the terminals 23a or 23b are almost the same magnitude as the power output from the transmitter 111 of the wireless PBX 100.

On the other hand, RF signals transmitted from the subscriber units 103a and/or 103b are first received by the internal antenna units 7a and 7b and coupled to the uplink amplifiers 3a or 3b via the combiners 6a or 6b and the dividers 5a and/or 5 b. These amplifier RF signals are also coupled to the receiver 112 of the wireless PBX100 through the coaxial cables 32a and/or 32b and the terminal 116. The other direction of the dividers 5a and 5b is coupled to the terminals 24a and 24b so as to connect the front stages of the distributed antennas 1a or 1 b. These RF signals transmitted from the subscriber units 103a or 103b are received by a receiver 112 having high sensitivity, since the amplifiers 3a and 3b compensate for the loss caused by the coaxial cables 32a and 32 b.

Referring to fig. 2, a wireless PBX100 constructed in accordance with the present invention is coupled to a terminal 25a or 25b of a distributed antenna 1a or 1b by a coaxial cable 33a or 33 b. In the distributed antenna 1a or 1b, as compared with fig. 1 above, distributors 10a and 11a and 10b and 11b are added for coupling with a single coaxial cable 33a or 33 b.

Referring to figure 3, control trunks and/or trunk lines and/or local line trunks 110 within a wireless PBX100 constructed in accordance with the present invention are coupled to an external base station 108 via an antenna 109. Downlink RF signals from the base station 108 are received through antenna 109 and coupled to receiver 112 through bandpass filter 129, divider 117 and antenna switch 128, and the receiver 112 detects the RF signals as baseband signals, while transmitter 111 modulates the baseband signals again to new RF signals by interconnecting the baseband signals between the receiver 112 and transmitter 111 in either TDMA relay mode or CDMA relay mode using baseband IC 12 and controller 113, and the RF signals are directed through antenna switch 127 and bandpass filter 125 to coaxial cable 31a on terminal 115 and through the distributed antenna described above in fig. 1 to the subscriber units 103a and/or 103 b.

On the other hand, the uplink RF signal on the terminal 116 transmitted from the subscriber unit 103a and/or 103b is amplified by the distributed antenna 1 described above in fig. 1, coupled to the receiver 112 through the band pass filter 126 and the antenna switch 128 and received by the receiver 112, and the receiver 112 detects a baseband signal among the RF signals, and the transmitter 111 modulates the baseband signal again into a new RF signal by interconnecting the baseband signal between the receiver 112 and the transmitter 111 in the TDMA or CDMA relay mode using the baseband IC 121 and the controller 113, and the RF signal is transmitted to the base station 108 through the antenna 109, the band pass filter 129, the distributor 117 and the antenna switch 127. Furthermore, these subscriber units 103a and 103b can talk to each other via the transceiver 110.

Referring to figure 4, another type of control trunk and/or repeater trunk 110 in a wireless PBX100 constructed in accordance with the present invention is coupled to an external base station 108 through an antenna 109. Downlink RF signals from the base station 108 are received by the antenna 109 and coupled to the receiver 112 through the band pass filter 129, divider 117 and antenna switch 128, and the receiver 112a detects the baseband signal in the RF signals, and the transmitter 111b modulates the baseband signal again to a new RF signal by interconnecting the baseband signal between the receiver 112a and the transmitter 111b in FDMA or cascade connection relay mode using baseband ICs 121a and 121b, and the RF signal is sent through the band pass filter 125 to the coaxial cable 31a on the terminal 115 and coupled to the subscriber units 103a and/or 103b through the distributed antenna described in fig. 1.

On the other hand, the uplink RF signal on the terminal 116 transmitted from the subscriber unit 103a and/or 103b is amplified by the distributed antenna 1 described in fig. 1 above and coupled to the receiver 112b through the band pass filter 126 and received by the receiver 112b, while the receiver 112b detects the baseband signal in the RF signal, and the transmitter 112b modulates the baseband signal between the receiver 112b and the transmitter 111a in FDMA or cascade connection relay mode using the baseband ICs 121a and 121b, and the RF signal transmitted to the base station 108 through the antenna 109, the band pass filter 129, and the distributor 117.

These controllers 113a and 113b can communicate with each other through a serial input/output port.

Referring to fig. 5, there is shown another type of local line trunk and/or three-way call trunk 110a and 110b, incoming and outgoing line trunks 204a and 204b, and data service trunk 205a in a wireless PBX100 constructed in accordance with the present invention. The uplink RF signal from subscriber unit 103a is coupled to distributed antenna 1a and also to one of receivers 112a and 112b through bandpass filter 126 and splitter 124, and the receiver 112a or 112b and transmitter 111a or 111b interconnect the baseband signals between the receiver 112a or 112b and transmitters 111a and 111b and controller 113a and/or 113b in TDMA or CDMA relay mode using baseband ICs 121a and/or 121b, and the RF signal is directed to the distributed antenna 1a and to subscriber unit 103a, as shown in fig. 1 above.

The incoming and outgoing trunks 204a and 204b are coupled to telephone lines 152a and 152b through terminals 151a and 151b and line interface units 114c and 114d, which line interface units 114c and 114d are also coupled to baseband ICs 121c and 121d and controllers 113c and 113 d.

The gateway service trunk 205a is coupled to an external LAN (local area network) 164 through a terminal 163 and a node 164a, and the remote access server 162 is further coupled to a baseband IC 121e and a controller 113 e.

The baseband ICs 121a, 121b, 113c, 113d, and 113e are connected to each other at nodes 154a, 154b, 154c, 154d, and 154e through a data common channel (Highway)154, and the controllers 113a, 113b, 113c, 113d, and 113e are connected to the LAN 153 at nodes 153a, 153b, 153c, 153d, and 153 e. The data highway 154 and the LAN 153 can be controlled and/or managed by a main controller 155. The baseband signals can be interconnected between these trunks and then incoming and outgoing calls, three-way calls, and other complex functions such as call forwarding, call waiting, etc. can be performed using the above scheme.

Referring to fig. 6, the control and/or trunk lines 201 and 202, local line trunk lines 203, and incoming and outgoing trunk lines 204 of a radio PBX100 constructed in accordance with the present invention are coupled to an external base station 108 by an antenna 109. Uplink RF signals from subscriber units 103a and/or 103b are coupled to receivers 112a, 112b, 112c and 112d through bandpass filter 126 and splitter 124a, while downlink RF signals from transmitters 111a, 111b, 111c and 111d are coupled to coaxial cable 31a on terminal 115 through combiner 123a and bandpass filter 125.

The incoming and outgoing trunk 204 is composed of the transceiver 110d and the line interface unit 114 connected to the telephone line 152 on the MDF 151 and connected to the distributor 124a and the combiner 123 a. The uplink RF signal at the terminal 116 from the subscriber unit 103a and/or 103b is coupled through a bandpass filter 126, a splitter 124a to a receiver 112d, and the receiver 112d detects the baseband signal in the RF signal and decodes it into voice band signal or data using a baseband IC 121 and an ADPCM decoder 141a or 141b and couples to a telephone line 152 through a line interface unit 114 and an MDF 151. Voice band signals or data from telephone line 152 are coupled to ADPCM encoders 141a or 141b through line interface unit 114 and converted to baseband signals, and transmitter 111d modulates the baseband signals to RF signals and couples to coaxial cable 31a on terminal 115 using combiner 123a and bandpass filter 125, and the RF signals are directed to subscriber units 103a and/or 103 b.

When additional trunks are added, the number of branches of the combiner 123a and the divider 124a must be increased.

Referring to fig. 7, in the wireless PBXs 100a and 100b, the control trunks 201a and 201b include at least: a set of digital transceivers 81a for transmitting control signals to and receiving control signals from subscriber units 103a and/or 103 b; the local line trunks 202a and 202b include digital transceivers 82a-82k to provide intercommunication between the subscriber units 104a and/or 104 b; the repeater trunks 203a and 203b include digital transceivers 83a-83m to provide connectivity between the incoming and outgoing line trunks 204 and the subscriber units 104a and/or 104 b. The RF terminals of the control trunk and repeater trunk are coupled to antenna splitters 51a, 51b, 52a and 52b, and the splitters 52a and 52b are also coupled to external antennas 109a and 109b through terminals 119a and 119b, while the RF terminals of the local line trunk are coupled to splitters 51a and 51b, and the splitters 51a and 51b are also connected to indoor antennas 53a or coaxial cables 31b and 32b for coupling with subscriber units 104a and/or 104 b. The incoming and outgoing trunk 204 includes transceivers 84a-84n, and the RF signals of the trunk 204 are coupled to the antenna 56 through the distributor 55 and the terminal 57. These antennas 56, 109b and 109a are remotely mounted and coupled through an open air propagation environment. In the present invention, the wireless PBX100 b functions as a tandem switch to interconnect the wireless PBX100 and the incoming and outgoing line trunks 204.

Referring to fig. 8, the wireless PBXs 100a, 100b, and 100c are coupled to the CATV cable network 60 by couplers (or taps) 58a, 58b, and 58c, to which incoming and outgoing line trunks 204 are also coupled by coupler 58 d. And the coupler 58d also combines CATV signals from the CATV head end. These transceivers 84a-84n in the inbound and outbound line trunks 204 operate originally, or have their operating frequency bands converted by converters, to CATV frequency bands (uplink 10MHz-50MHz, downlink 70MHz-550MHz) that are allocated to the existing CATV cable network. The transceivers 83a, 83a-83m and 81a, 82a-82k and 83a-83m in the radio PBXs 100a, 100b and 100c, when coupled to the couplers (or taps) 58a, 58b and 58c through the distributors 52a, 52b and 52c, operate originally, or are converted by converters, in their operating frequencies to the frequency bands assigned to the CATV cable network.

The transceivers 83a, 83a-83m and 81a, 82a-82k and 83a-83m in the wireless PBXs 100a, 100b and 100c, on the other hand, are coupled to antennas 53a, 53b or coaxial cables 31c and 32c, the operating frequency bands of which are converted by converters to the frequency bands (e.g., 1.9GHz) allocated to the subscriber units 104a and 104 b.

The transceivers 83a, 83a-83m and 81a, 82a-82k and 83a-83m relay baseband signals through the interconnection between the transmitter and receiver in FDMA or cascade connection relay mode, TDMA or CDMA relay mode. The CATV amplifier amplifies the CATV signals, which include RF signals sent to and from the transceivers 84a-84n in the incoming and outgoing line trunks 204. If a radio PBX is installed in an area remote from the line trunk 204, the radio PBX must adjust the transmit timing toward the line trunk 204 to compensate for the delay, as explained below in fig. 11.

Referring to figure 9, the wireless PBXs 100a, 100b and 100c are coupled to the coaxial cable 60 by couplers 58a, 58b and 58c, and the inbound and outbound line trunks 204 are also coupled to the coaxial cable 60 by coupler 58 d. These transceivers 84a-84n in the inbound and outbound line trunks 204 operate originally, or their operating frequency bands are converted by a converter, to the frequency band allocated to the cable network (e.g., 60MHz for uplink, 70MHz for downlink). The transceivers 83a-83m in the radio PBXs 100a, 100b, and 100c were originally operating in, or their operating frequency bands were converted by converters to, the frequency bands allocated to the coaxial cable network when the transceivers were coupled to the couplers 58a, 58b, and 58c through the distributors 52a, 52b, and 52 c.

On the other hand, those transceivers 83a-83m in radios 100a, 100b and 100c coupled to antennas 53a, 53b and 53c through distributors 51a, 51b and 51c operate originally, or have their operating frequency bands converted by converters, to the frequency band (e.g., 1.9GHz) distributed to subscriber unit 104 a.

The transceivers 83a-83m relay baseband signals through the interconnection between the transmitter and receiver in FDMA or cascade connection relay mode, TDMA or CDMA relay mode. The booster amplifier can be used to amplify the RF signals transmitted to the transceivers 84a-84n and the RF signals from the transceivers 84a-84n in the incoming and outgoing line trunk 204. If a wireless PBX is located in an area away from the line trunk 204, the wireless PBX must adjust the transmit timing toward the line trunk 204 to compensate for the delay, as explained in fig. 11 below.

If the wireless PBXs 100a, 100b, and 100c are simultaneously transmitting to the subscriber unit 103a in the same frequency, the subscriber unit 103a can continue communication towards the telephone line 152 without interruption because the RF signals come from multiple directions as long as the subscriber unit 103a is positioned along the coaxial cable 60. Conversely, when the radio PBXs 100a, 100b and 100c simultaneously forward RF signals from the subscriber unit 103a over the coaxial cable 60, and if the power output level of the forwarded RF signals to the line trunk 204 is controlled according to the level received from the subscriber unit 103a, the receiver in the line trunk 204 can receive the RF signals using a maximum ratio diversity mode (diversity mode). Whereas if a frequency channel is individually assigned to each wireless PBX, the receiver in the line trunk 204 can receive the RF signal using a selection diversity mode.

Referring to fig. 10, wireless PBX100a is coupled to coaxial cable or CATV cable by coupler 58a, and on the other hand, antenna 53a is connected to said wireless PBX100a at terminal 62a and is coupled to subscriber unit 104a or 104 b. When an uplink RF signal from the subscriber unit 104a or 104b is received on terminal 54a, the RF signal is also coupled to the receiver 112a in the transceiver 110a through the band pass filter 63a, the divider 51a and the antenna switch 128a, then a baseband signal in the RF signal is detected and forwarded to the transmitter 117a by interconnecting the baseband signal in the TDMA relay mode or the CDMA relay mode using the baseband ICs 121a and 113a, and the baseband signal is also modulated into an RF signal and coupled to the coupler 58a through the antenna switch 127a, the down converter 67a, the band pass filter 65a, the attenuator 69a and the divider 117 a. The transmission timing is controlled by the timing adjusting unit 62a, and the transmission power output level is controlled by the attenuator 69a, and this transmission timing and transmission power output level are also controlled by the controller 113 a.

The downlink RF signal from coupler 58a is coupled through divider 117a, delay line 68a, band pass filter 64a, antenna switch 128a of up-converter 66a to receiver 112a in transceiver 110a, and then the baseband signal of the RF signal is detected in the TDMA relay mode or CDMA relay mode using baseband IC 121a and controller 113a, and also modulated as a new RF signal and coupled through antenna switch 127a, divider 51a, band pass filter 63a and terminal 54a to 53 a. The delay line 68a is automatically controlled by the controller 113a or is preset manually so as to adjust the transmission timing of a new RF signal in accordance with the reception timing of the RF signal transmitted from the line trunk 204 in accordance with the distance from the line trunk 204. Details of the control scheme are further discussed in fig. 11.

Referring to fig. 11, 228c shows the transmission timings TX1, TX3 and reception timings RX1, RX3 on the wireless PBX100c closest to the incoming and outgoing line trunks 204, and 228b, the transmission timings TX1, TX3 and the reception timings RX1, RX3 on the wireless PBX100 b located some distance from the line trunk 204, and 228a, transmission timings TX1, TX3 and reception timings RX1, RX3 on the wireless PBX100a remote from the line trunk 204, where RX1 is the timing of when RF signals transmitted from the line trunk 204 are received on the wireless PBX, TX1 is the timing of the reception of RF signals on the wireless PBX, TX1 is the timing of the reception of RF signals from the wireless PBX on the line trunk 204, RX3 is the RF signal transmitted from the subscriber unit 103a, the timing of when received on radio BPX, and TX3 is the timing of when RF signals are received from the wireless PBX at the subscriber unit 103 a.

In 228c, it is assumed that any visible delays do not occur in the transmit timing or the receive timing. In 228b, some visible delay 226a t2 appears in the reception timing RX1, while other timings TX1, RX3, and TX3 than the one shown by the dotted line are adjusted. In 228a, another visible delay 227 a-t 3 appears in the reception timing RX1, while other timings TX1, RX3 and TX3 than the one shown by the dotted line are adjusted. With this processing, the reception timing TX1 on the line trunk 204 can be adjusted in the same timing of any wireless PBX.

Referring to fig. 12, transmission timing and reception timing are repeated in an uplink RF signal and a downlink RF signal. The transmission timings 211a and 211b (TX1, TX2, TX3 and TX4) and the reception timings 212a and 212b (RX1, RX2, RX3 and RX4) are one set of TDD (time division duplex) timings, and the transmission timings 213a and 213b (TX1, TX2, TX3 and TX4) and the reception timings 214a and 214b (RX1, RX2, RX3 and RX4) are the other set of TDD timings. These two timings can be carried within a single coaxial cable as shown in 215a and 215 b.

Claims (18)

1. A wireless private branch exchange (BPX) for use in a digital mobile communication system forming a microcell service area, comprising:

(1) a plurality of transceivers for transmitting and receiving radio frequency signals to and from the subscriber units;

(2) a common antenna means coupled to said transceivers;

(3) repeater means interconnecting baseband signals between a set of transmitters and receivers of said transceivers;

(4) the transceiver forms a trunk line device; and

(5) and a control device for controlling the relay device according to the control signal detected from the radio frequency signal.

2. A wireless PBX for use in a digital mobile communications system forming a microcell service area, comprising:

(1) a plurality of transceivers for transmitting and receiving radio frequency signals to and from external base stations and subscriber units;

(2) a first common antenna means and a second common antenna means coupled to said transceiver;

(3) an antenna selection device between the first common antenna device and the second common antenna device;

(4) repeater means interconnecting baseband signals between a set of transmitters and receivers of said transceivers;

(5) the transceiver forms a trunk line device; and

(6) and a control device for controlling the relay device according to the control signal detected from the radio frequency signal.

3. A radio PBX according to claim 1 or 2, wherein the transceivers are tailored and allocated to control trunks, local line trunks, trunk lines, service trunks, incoming and outgoing line trunks and other necessary trunks.

4. A wireless PBX according to claim 1, 2 or 3, wherein the incoming and outgoing line trunks and the trunk line trunk are coupled by open air propagation.

5. A wireless PBX according to claim 1, 2 or 3, wherein the incoming and outgoing line trunks and the trunk transmission are coupled by radio frequency transmission means.

6. The radio PBX of claim 1, 2, 3, 4 or 5, wherein the relay device interconnects the baseband signals between a set of receivers and transmitters by employing one of the following schemes:

(1) FDMA or cascade connection repeater mode;

(2) TDMA repeater mode; and

(3) CDMA repeater mode.

7. The wireless PBX of claim 1, 2, 3, 4 or 5, wherein the common antenna device includes:

(1) at least one radio frequency transmission means coupled to said common antenna means;

(2) two isolated amplifier devices amplifying the downlink radio frequency signal and the uplink radio frequency signal;

(3) two divider means (divider means) dividing the downlink radio frequency signal and the uplink radio frequency signal into more than two directions;

(4) an internal antenna device coupled to one direction of the divider device; and

(5) at least one radio frequency transmission device connected with the other direction of the distributor device.

8. The wireless PBX of claim 1, 2, 3, 4 or 5, wherein the common antenna device includes:

(1) at least one radio frequency transmission means coupled to said common antenna means;

(2) two independent amplifier devices amplifying the downlink radio frequency signal and the uplink radio frequency signal;

(3) two splitter devices that split the downlink radio frequency signals and the uplink radio frequency signals into more than two directions;

(4) an antenna means coupled to one direction of the divider means through a combiner means; and

(5) said combiner means comprising at least one set of a transmitter and a receiver to detect said baseband signal in said radio frequency signal and modulate said baseband signal into a new radio frequency signal by interconnecting said baseband signal between said transmitter and receiver and to forward said radio frequency signal between said divider means and said antenna means; and

(6) at least one radio frequency transmission cable connected to the other direction of the distributor device.

9. The wireless PBX of claim 1, 2, 3, 4 or 5, wherein the common amplifier means compensates for losses occurring in the splitter and combiner means to couple the plurality of receivers and transmitters.

10. The wireless PBX of claim 1, 2, 3, 4 or 5, wherein each of the transceivers includes at least one controller device, and each of the controller devices installs a control program including a mutual communication program.

11. The wireless PBX of claim 1, 2, 3, 4 or 5, wherein the baseband signals of each transceiver are interconnected by a data public channel (highway) arrangement.

12. The wireless PBX of claim 1, 2, 3, 4 or 5, wherein at least one common controller device is in communication with the controller devices in each transceiver.

13. The wireless PBX of claim 1, 2, 3, 4, or 5, wherein the incoming and outgoing line trunks are directly coupled to the data public channel.

14. The wireless PBX system of claim 1, 2, 3, 4, or 5, wherein a frequency band coupling the incoming and outgoing line trunks and the repeater trunk is different from a frequency band coupling the repeater trunk with the subscriber unit.

15. The wireless PBX system of claim 1, 2, 3, 4, or 5, wherein an uplink frequency band coupling the incoming and outgoing trunks and the trunk lines is different from a downlink frequency band coupling the incoming and outgoing trunks and the trunk lines.

16. The radio PBX system of claim 1, 2, 3, 4 or 5, wherein the trunk line includes:

(1) at least one set of transmitters and receivers for relaying radio frequency signals between remotely located trunk equipment and subscriber units;

(2) a timing adjusting means for adjusting the timing of transmitting the radio frequency signal to the subscriber unit and causing the subscriber unit to receive the radio frequency signal at the same timing;

(3) a timing adjustment device for adjusting the timing of transmitting the radio frequency signal to the relay line device and enabling the relay line device to receive the radio frequency signal at the same timing; and

(4) and a level adjusting means for adjusting the level transmitted to the relay device in accordance with the level received from the subscriber unit.

17. The wireless PBX system according to claim 1, 2, 3, 4, or 5, wherein the first and second relay devices operate in a time division duplex mode, and radio frequency signals of the relay devices are combined together with inter-digital timing to share a set of downlink and uplink radio frequency transmission devices.

18. The wireless PBX system of claim 1, 2, 3, 4 or 5, wherein the individual assigned frequency of each repeater trunk transmits its radio frequency signal to a remotely located repeater device.