Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
1998-06-29
2002-01-08
Bost, Dwayne (Department: 2681)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S560000, C455S554100, C379S225000, C370S347000
Reexamination Certificate
active
06337979
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communication controlling apparatus in a local area radio system using a PDC (Personal Digital Cellular) portable terminal unit, in particular, to an audio
on-audio PDC communication controlling apparatus that is connected to a private branch exchange (PBX), that has the same service as a public PDC system, and that provides the service of the PBX.
2. Description of the Related Art
As the number of subscribers to digital portable telephone systems drastically increases, various new services are required. In addition, analog or digital telephone units used in offices and so forth require complicated wiring connections. Thus, fixed telephone units are inconvenient. To solve such problems, radio telephone systems have been constructed.
FIG. 6
is a schematic diagram showing the structure of a conventional radio telephone system as disclosed in Japanese Patent Laid-Open Publication No. Hei6-22360.
In the related art reference shown in
FIG. 6
, the radio telephone system is composed of a radio terminal unit
617
and a radio terminal unit controlling unit
600
. The radio terminal unit controlling unit
600
is connected to a private branch exchange (PBX) or the like (not shown).
The radio terminal unit controlling unit
600
comprises a radio terminal unit communication portion
615
, a controlling portion
601
, an exchange communication portion
604
, a two-wire/four-wire converting portion
610
, a hook relay switch
608
, a dial relay switch
609
, and a selecting switch
611
. A modular jack
619
can be used for both a two-wire type interface and a four-wire type interface of the PBX. With two-wire type signal lines
605
-R, the radio terminal unit controlling unit
600
is connected to the PBX. A bell detecting portion
607
detects a bell signal received from one of the signal lines
605
-R through a capacitor
606
. The controlling portion
601
generates a trigger signal. A DTMF (Dual Tone Multi-Frequency) signal generator
612
generates a DTMF signal. The selecting switch
611
selects the trigger signal or the DTMF signal and outputs the selected signal to the PBX or the like.
When an origination call, a termination call, a dialing signal, display data, and so forth are sent and received to/from the PBX, the controlling portion
601
controls the exchange communication portion
604
. Such data is transmitted to the radio terminal unit
617
through the radio terminal unit communication portion
615
and an antenna
616
.
An audio band signal is sent to the PBX through the radio terminal unit communication portion
615
, the two-wire/four-wire converting portion
610
, and the modular jack
619
.
The controlling portion
601
causes the radio terminal unit communication portion
615
to autonomously search a radio frequency free of an external interference and determine an operation frequency. In addition, the controlling portion
601
causes the radio terminal unit
617
to select a channel through the radio terminal unit communication portion
615
.
In other words, according to the related art reference, the controlling portion
601
determines whether or not the interface of the PBX is two-wire type or four-wire type, adaptively converts an audio band signal received from the radio terminal unit
617
into a particular signal, and autonomously determines an operation signal, thereby suppressing the operation frequency from interfering another unit and from being interfered by another unit. However, the radio terminal unit
617
of the system should be disposed in a radio cover area of the radio terminal unit controlling unit
600
accommodated in the PBX.
Thus, in the local area radio system composed of the PBX, the small radio base station, and the radio terminal unit, since communications are available only in the radio cover area of the radio base station accommodated in the PBX, the usability of the system is low.
In addition, since it is difficult to exchange a control signal among a plurality of terminal unit controlling units, while a radio terminal unit is moving, a user thereof cannot communicate to another user.
Moreover, due to the system structure, it is difficult to share the system with a non-audio communication (such as FAX and data communication) and an audio communication.
SUMMARY OF THE INVENTION
The present invention is made from the above-described point of view. An object of the present invention is to provide a PDC communication controlling apparatus that has the following features. A PDC portable telephone terminal unit instead of a conventional wired telephone unit used in an office is used in a local area radio system that will be increasingly used year after year. Thus, the PDC portable telephone terminal unit is used as an office telephone unit that has an extension communication function with high mobility. A plurality of PDC portable telephone terminal units can be connected to the PBX. Each PDC portable telephone terminal unit can transmit not only an audio band signal, but a non-audio signal (such as FAX and data). While a PDC portable telephone terminal is moving, it can transmit both an audio signal and a non-audio signal as with a conventional public PDC system. Moreover, services of the PBX are provided. Thus, the usability of a PDC portable telephone terminal unit can be further improved.
A first aspect of the present invention is a PDC communication controlling apparatus, comprising an audio processing means for converting a digital audio signal that has been encoded at a transmission rate of a personal digital cellular (PDC) into a digital audio signal at a transmission rate of a digital exchange network, a small radio base station controlling means accommodating a plurality of small radio base stations that are connected to PDC portable terminal units through radio circuits and that have different radio cover areas, the small radio base station controlling means managing the radio cover areas of the PDC portable terminal units, controlling calls, and controlling and managing the radio circuits, a network-side adaptor used in non-audio communications with the PDC portable terminal units, a PDC
etwork interface means connected to a private branch exchange through a plurality of communication paths, a time division switch for connecting the PDC
etwork interface, the audio processing means, the radio base station controlling means, and the network-side adaptor and for switching the connection state thereof under the control of the small radio base station controlling means on time division basis, wherein the small radio base station controlling means separates the PDC
etwork interface means from the network-side adaptor in the case that a termination call is an audio communication, places the network-side adaptor between the PDC
etwork interface means and the audio processing means in the case that the termination call is a non-audio communication, and loops back the communication path for an extension communication in the case that the termination call is a communication performed between the PDC portable terminal units.
A second aspect of the present invention is a PDC communication controlling apparatus, comprising an audio processing means for converting a digital audio signal that has been encoded at a transmission rate of a personal digital cellular (PDC) into a digital audio signal at a transmission rate of a digital exchange network, a plurality of small radio base stations having different radio cover areas, a small radio base station controlling means, connected to the small radio base stations, for managing the radio cover areas of PDC portable terminal units, controlling calls, and controlling and managing radio circuits, a network-side adaptor used in non-audio communications with the PDC portable terminal units, a PDC
etwork interface means connected to a private branch exchange through a plurality of communication paths, a time division switch for connecting the PDC
etwork interface, the small radio base station controll
Bost Dwayne
Craver Charles
NEC Corporation
Young & Thompson
LandOfFree
PDC (personal digital cellular) communication controlling... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with PDC (personal digital cellular) communication controlling..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and PDC (personal digital cellular) communication controlling... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2836162