Mobile communication system

Details Mobile communication system Mobile communication system

1999-08-04

2003-05-13

Nguyen, Lee (Department: 2746)

Telecommunications

Radiotelephone system

Zoned or cellular telephone system

C455S445000, C455S435100, C379S221010

Reexamination Certificate

active

06564054

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mobile communication system, and in particular to a mobile communication system composed of a private branch exchange (hereinafter occasionally abbreviated as PBX) connected to a mobile communication network through an interface unit and having a semi-public roaming function.
In recent years, with the semi (quasi)-public roaming function by which a public PHS (hereinafter simply referred to as PHS) as a mobile station can have services equal to those in the mobile communication network through a base station within the PBX, utilities of the PHS have been spread. It is important to certainly perform a position registration, a call transmission and a call reception between the PHS and the mobile communication network so that the PHS may have the services equal to those in the mobile communication network.
2. Description of the Related Art
FIG. 52
shows an arrangement of a prior art mobile communication system. This mobile communication system is composed of a base station (hereinafter abbreviated as BS)
19
having a PHS
22
within a semi-public area
80
, a PBX
16
having a semi-public roaming function and accommodating the BS
19
, and a PIU (PHS Interface Unit)
13
connecting the PBX
16
to a mobile communication network
10
.
The mobile communication network
10
accommodates a public base station
91
which exists in a public base station management area
90
and is connected to a fixed communication network
92
to form a public communication network
93
.
The PHS
22
makes a position registration in the mobile communication network
10
through the BS
19
, the PBX
16
, and the PIU
13
. The PHS
22
controls the call transmission, the call reception, or the like together with a mobile station (not shown) existing in the area
90
or a telephone
94
accommodated in the fixed communication network
92
.
Namely, the PBX
16
mediates a position registration and a call from the PHS
22
existing in the semi-public area
80
not covered with a radio wave of the public base station
91
to the mobile communication network
10
and a call from the mobile communication network
10
to the PHS, thereby enabling communications therebetween.
FIG.53
shows a principle of the position registration by the semi-public roaming function of the PBX
16
. BS's
19
and
20
existing in general calling areas
81
and
82
respectively including PHS's
22
and
23
are accommodated in the PBX
16
. This PBX
16
controls all of the PHS's existing in the semi-public area
80
including the areas
81
and
82
and is connected to the mobile communication network
10
through the PIU
13
.
The PBX
16
makes a position registration in the mobile communication network
10
with a “normalizing call area No.” corresponding to the general calling area where the PHS exists as PHS position information. The position information of the PHS's
22
and
23
, for instance, is supposed to have the “normalizing call area No.” of e.g. “1” and “2” respectively corresponding to the general calling areas
81
and
82
where the PHS's
22
and
23
exist for performing the position registration.
This will be described referring to a position registration sequence shown in FIG.
54
. The BS
19
receives a SETUP message (position registering request) including a PS No. and the like from the PHS
22
to transmit the message to the PBX
16
(at step R
10
).
The PBX
16
returns a CALL-PROC message to the BS
19
and converts the SETUP message into a REGISTER message by the addition of the “normalizing call area No.”=“1” corresponding to the general calling area
81
(the BS
19
) where the PHS
22
exists to transmit the REGISTER message to the PIU
13
.
The PIU
13
stores the “normalizing call area No.”=“1” and transmits the REGISTER message excluding the “normalizing call area No.” to the mobile communication network
10
to make the position registering request (at step R
11
).
Hereinafter, a FACILITY message (a certification request) from the mobile communication network
10
is converted into an INFO message at the PBX
16
to be sent to the BS
19
(and in turn the PHS
22
) (at step R
12
), the INFO message (a certification response) from the BS
19
being converted into the FACILITY message to be transmitted to the mobile communication network
10
(at step R
13
), so that an REL-COMP message from the mobile communication network
10
is converted into a DISC message to be transmitted to the BS
19
(at step R
14
).
An REL message and the REL-COMP message are transmitted/received between the BS
19
and the PBX
16
to finish the position registration (at steps R
15
and R
16
).
FIG. 55
shows a call reception sequence by the semi-public roaming function. When receiving a calling No., a called number, and the SETUP message (call reception request) including the PS No. from the mobile communication network
10
, the PIU
13
prepares a SETUP message added with the “normalizing call area No.” stored and transmits the SETUP message to the PBX
16
.
The PBX
16
transmits the SETUP message excluding the “normalizing call area No.” to the BS
19
(and in turn the PHS
22
) corresponding to the “normalizing call area No.” included in the received SETUP message (at step R
20
).
Hereinafter, the CALL-PROC message is transmitted from the BS
19
to the mobile communication network
10
(at step R
21
). After the messages of the certification request and the certification response are transmitted/received (at steps R
22
and R
23
) in the same way as the position registering sequence, an ALERT message and a CONN message are sequentially transmitted from the BS
19
to the mobile communication network
10
(at steps R
24
and R
25
). After a CONN-ACK message which is a response message of the CONN message is transmitted from the mobile communication network
10
to the BS
19
(at step R
26
), the communication is started (at step R
27
).
Next, a call transmission sequence by the semi-public roaming function will be described referring to FIG.
56
.
The BS
19
transmits the SETUP message including the calling No., the called number and the PS No. to the mobile communication network
10
through the PBX
16
and the PIU
13
(at step R
30
). After transmitting the CALL-PROC message to the BS
19
(at step R
31
), the mobile communication network
10
transmits/receives the messages of the certification request and the certification response to/from the BS
19
(at steps R
32
and R
33
).
After the ALERT message and the CONN message are transmitted from the mobile communication network
10
to the BS
19
through an RBT (Ring Back Tone) step (at steps R
34
, R
35
, and R
36
), the communication is started (at step R
37
).
When none of the PIU's connected to the PBX
16
is available due to a fault, congestion, non-equipping, and the like in such a prior art mobile communication system, it become impossible to perform the position registration or the call transmission from the PHS
22
and the call reception to the PHS
22
. Accordingly, the PHS
22
is not able to communicate with the mobile communication network
10
through the PBX
16
having the semi-public roaming function unless the PIU becomes available after recovering from the fault, relieving the congestion, being equipped, or the like.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a mobile communication system composed of a PBX connected to a mobile communication network and having a semi-public roaming function wherein communications are realized between a PHS and a mobile communication network through the PBX where a PIU is not equipped or is unavailable.
In order to achieve the above-mentioned object, a mobile communication system, according to claim 1, of the present invention comprises; a first exchange for accommodating a base station which communicates with a mobile station, and a second exchange having a semi-public roaming function connected to the first exchange wit

Affiliated with

Also associated with

Rating

Mobile communication system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Mobile communication system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mobile communication system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3004459