Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
1999-05-06
2001-09-18
Maung, Nay (Department: 2744)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S432300, C455S435100, C455S457000, C455S566000, C455S427000, C455S012100
Reexamination Certificate
active
06292666
ABSTRACT:
BACKGROUND AND OBJECTS OF THE PRESENT INVENTION
Cellular telecommunications is one of the fastest growing and most demanding telecommunications applications. Today it represents a large and continuously increasing percentage of all new telephone subscriptions around the world. A standardization group, European Telecommunications Standards Institute (ETSI), was established in 1982 to formulate the specifications for the Global System for Mobile Communication (GSM) digital mobile cellular radio system.
With reference now to
FIG. 1
of the drawings, there is illustrated a GSM Public Land Mobile Network (PLMN), such as cellular network
10
, which in turn is composed of a plurality of areas
12
, each with a Mobile Switching Center (MSC)
14
and a Visitor Location Register (VLR)
16
therein. The MSC/VLR areas
12
, in turn, include a plurality of Location Areas (LA)
18
, which are defined as that part of a given MSC/VLR area
12
in which a Mobile Station (MS)
20
may move freely without having to send update location information to the MSC/VLR
14
/
16
that controls the LA
18
. Each LA
12
is divided into a number of cells
22
. The MS
20
is the physical equipment, e.g., a car phone or other portable phone, used by mobile subscribers to communicate with the cellular network
10
, each other, and users outside the subscribed network, both wireline and wireless.
The MSC
14
is in communication with at least one Base Station Controller (BSC)
23
, which, in turn, is in contact with at least one Base Transceiver Station (BTS)
24
. The BTS
24
is the physical equipment, illustrated for simplicity as a radio tower, that provides radio coverage to the geographical part of the cell
22
for which it is responsible. It should be understood that the BSC
23
may be connected to several BTS's
24
, and may be implemented as a stand-alone node or integrated with the MSC
14
. In either event, the BSC
23
and BTS
24
components, as a whole, are generally referred to as a Base Station System (BSS)
25
.
With further reference to
FIG. 1
, the PLMN Service Area or cellular network
10
includes a Home Location Register (HLR)
26
, which is a database maintaining all subscriber information, e.g., user profiles, current location information, International Mobile Subscriber Identity (IMSI) numbers, and other administrative information. The HLR
26
may be co-located with a given MSC
14
, integrated with the MSC
14
, or alternatively can service multiple MSCs
14
, the latter of which is illustrated in FIG.
1
.
The VLR
16
is a database containing information about all of the MS's
20
currently located within the MSC/VLR area
12
. If an MS
20
roams into a new MSC/VLR area
12
, the VLR
16
connected to that MSC
14
will request data about that MS
20
from the HLR database
26
(simultaneously informing the HLR
26
about the current location of the MS
20
). Accordingly, if the user of the MS
20
then wants to make a call, the local VLR
16
will have the requisite identification information without having to reinterrogate the HLR
26
. In the aforedescribed manner, the VLR and HLR databases
16
and
26
, respectively, contain various subscriber information associated with a given MS
20
.
It should be understood that the aforementioned system
10
, illustrated in
FIG. 1
, is a terrestrially-based system. In addition to the terrestrially-based systems, there are a number of satellite systems, which work together with the terrestrially-based systems to provide cellular telecommunications to a wider network of subscribers. This is due to the fact that the high altitude of the satellite makes the satellite visible (from a radio perspective) from a wider area on the earth. The higher the satellite, the larger the area that the satellite can communicate with.
Within a satellite-based network
10
, as shown in
FIG. 2
of the drawings, a system of satellites
200
(only one of which is shown) in orbit are used to provide communication between MS's
20
and a satellite-adapted Base Station System (SBSS)
220
, which is connected to a Mobile Switching Center
14
. The MS
20
communicates via one of the satellites
200
using a radio air interface. The satellite
200
in turn communicates with one or more SBSSs
220
, which consist of equipment for communicating with the satellites
200
and through the satellites
200
to the MS's
20
. The antennae and satellite tracking part of the system is the Radio Frequency Terminal (RFT) subsystem
230
, which also provides for the connection of the communication path to the satellite
200
.
In such satellite networks
10
, a coverage area
205
for a satellite
200
can be (and usually is) very large. This area
205
can be served by a number of MSCs
14
which are connected to Public Switched Telephone Networks (PSTNs) (wireline networks), PLMNs (cellular networks) and each other. As in a normal GSM system, each MSC
14
may serve a number of different SBSS's
220
, each of which are associated with a particular set of satellite cells
250
. It should be understood that the coverage area for a satellite cell
250
is much larger than the coverage area for a normal GSM cell
22
(shown in FIG.
1
). This is due to the fact that a satellite beam
210
directed at a particular satellite cell
250
can cover more area than a signal transmitted from a BTS
24
(shown in
FIG. 1
) on earth.
The satellite
200
transmits a different beam
210
to each satellite cell
250
. When an MS
20
moves from one satellite cell
250
into a new satellite cell
250
, the MS
20
detects this change by the presence of a new satellite beam
210
for that new satellite cell
250
. This triggers the MS
20
to perform a location update. During the location update process, the current PLMN
10
is displayed to the mobile subscriber on the MS
20
. Therefore, the mobile subscriber knows whether the MS
20
has roamed outside of the home network
10
.
However, if a mobile subscriber crosses a boundary between two countries, this information may not be transmitted to the mobile subscriber. In many cases, the boundaries between countries are not obvious, and the PLMN
10
that the MS
20
is registered with may span several countries. Having knowledge of these boundaries may help the mobile subscriber in making originating calls as to which dialing plan is applicable. For example, if a subscriber has just unknowingly roamed from Germany to Holland, and he/she dials a number to a German subscriber in national format, the call will be routed to Holland instead. Thus, in such cases, valuable satellite resources are used, but the call is routed incorrectly.
Even if the country information is transmitted to the MS
20
during the location update process, the MS
20
may not perform the location update until after the border has been crossed and the mobile subscriber has traveled several miles into the other country. This delay in performing location updates may be due to a number of factors, such as cell reselection hysteresis and cell movement in the satellite network.
Currently, when an MS
20
within a satellite PLMN
10
originates a call to a dialed B-number, the MS
20
provides Global Positioning System (GPS) coordinate information to the satellite network (MSC
14
). The MSC
14
takes this GPS coordinate information and utilizes a database
15
of GPS coordinates and associated country codes to append the country code in front of the B-number. If the MS
20
had a similar type of database within it, the MS
20
may be able to convert received GPS coordinates into the current country and display the current country to the mobile subscriber. However, the database in the MS
20
would have to be limited, because it would not be possible to cover all potential coordinates and associated countries and store this information in a memory that would fit into an MS
20
. In addition, the database within the MS
20
may not produce exactly the same country as the network database
15
. As an example, if the MS
20
displays Germany and the m
Alperovich Vladimir
Siddiqui Aqeel
Davis Temica M.
Ericsson Inc.
Jenkens & Gilchrist P.C.
Maung Nay
LandOfFree
System and method for displaying country on mobile stations... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method for displaying country on mobile stations..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method for displaying country on mobile stations... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441276