Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
1999-12-10
2002-05-07
Urban, Edward F. (Department: 2746)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S435100, C455S436000, C455S512000, C455S527000, C455S440000, C455S432300
Reexamination Certificate
active
06385458
ABSTRACT:
TECHNICAL FIELD
The present invention generally relates to mobile communication networks, including cellular-type wireless networks, and, more particularly to a method and computer program for assigning and managing priority for location services in a mobile communication network.
BACKGROUND OF THE INVENTION
Mobile Communications Networks
FIG. 1
(Prior Art) illustrates a block diagram of a mobile communications network
10
comprising a terminal device, illustrated as an originating mobile phone
12
, coupled by an RF communication link to an originating network
14
. The terminal device is preferably a mobile phone
12
, but could be any wireless communication device such as a pager, a Personal Digital Assistant (PDA), or a Mobile Computing Device (MCD), for example, but may also be a fixed wireless device. The mobile phone
12
may operate based on any number of communication standards including AMPS, TDMA, D-AMPS, GSM, IS-95, or third generation (3G) protocols, for example.
The originating network
14
is seen to be coupled to a transit network or communication link
16
, which may comprise a public switched telephone network (PSTN), but could also comprise of other networks including an Internet Protocol (IP) core network, an Asynchronous Transfer Mode (ATM) core network, or an optical network, for example. The transit network
16
interfaces and communicates electrical signals including digitized voice calls between the originating network
14
and a destination network
18
. Destination network
18
may be the same as, or different than, the originating network
14
, and thus may comprise AMPS, D-AMPS, TDMA, GSM IS-95, or 3G networks such as UMTS. Terminating network
18
is coupled to and services, via a Radio Frequency (RF) link, a destination terminal device, shown to be a mobile phone
20
.
The originating network
14
is seen to include a base transceiver station (BTS)
30
serving via a radio frequency (RF) link the originating mobile phone
12
. Each BTS
30
services multiple mobile phones
12
, although only one is shown for purposes of illustration and clarity. Each BTS
30
also includes a Location Measurement Unit (LMU)
22
(the LMU
22
may also be physically located outside of the BTS
30
).
The LMU
22
measures the distance between the mobile phone
12
and the LMU
22
and reports the distance to a Base Station Controller (BSC)
32
. Accordingly, originating network
14
further includes a BSC
32
and a Mobile Switching Center (MSC)
34
, which can communicate with each other via Direct Transfer Application Part (DTAP) messaging. The network
14
is connected through the MSC
34
to a Gateway Mobile Location Center (GMLC)
36
, and communicates with Mobile Application Part (MAP) messaging protocol. The GMLC
36
provides the hardware connections needed to interface the network
14
with the transfer network
16
, and houses selected processing functions as well. In addition, the GMLC
36
interfaces to users of a location service that is seeking the location of a mobile phone or other terminal device, performs user authorization tasks, and also forwards positioning requests to the mobile phone's current mobile network.
Likewise, the GMLC
36
communicates with a Serving Mobile Location Center (SMLC)
38
via Mobile Application Part (MAP) messaging. The SMLC
38
provides the network resources needed to process calls in the network, and particularly to locate a mobile phone, and is directly associated with the MSC communicating with a mobile station that is being located. More particularly, the primary task of the SMLC
38
is to decide upon a positioning method to use to estimate the location of a mobile phone (various methods are discussed below). Note that the BTS
30
and BSC
32
are sometimes collectively referred to as a Base Station Subsystem (BSS).
The BSC
32
interfaces voice calls between multiple BTSs
30
and MSC
34
, wherein BSC
32
typically serves multiple BTSs
30
, and, similarly, MSC
34
services multiple BSCs
32
. MSC
34
includes a visitor location register (VLR) which includes and stores various information regarding the mobile phones
12
currently being served by the originating network
14
.
The destination network
18
includes a BTS
40
serving the destination mobile phone
20
, as well as a BSC
42
and an MSC
44
. Destination network
18
may operate according to the same or a different operating protocol as originating network
14
. MSCs
34
,
44
each include a VLR for maintaining a register of information for all mobile phones
20
currently being served by the destination network
18
. Thus, the MSCs may also be referred to as MSC/VLRs.
Transit network
16
is preferably a PSTN. Originating MSC
34
and terminating MSC
44
exchange digitized voice data over the transit network
16
, in preferably an encoded Pulse Code Modulation (PCM) format, transmitted at about 64 kbps. Although PCM is a preferred encoding format, other encoding formats are available. Generally, the digitized voice data transferred over transit network
16
can be in any format which is compatible and supported by both the originating network
14
and the destination network
18
.
Locating a Mobile Phone
There are many reasons why one would want to locate a mobile phone (such as a mobile phone or a pager, for example). For example, investigative agencies, such as the Federal Bureau of Investigation (FBI) and the National Security Agency (NSA) have an interest in locating persons for the purposes of law enforcement and surveillance. Likewise, private companies and individuals often need location data. For example, a Taxi company may wish to monitor the location of its cabs, or to provide them instant access to directions. Likewise, a parent may wish to know the location of a son or daughter who may be out on a date.
One service that needs location information and is highly desired by mobile phone users is the ability to use an emergency number, such as 911. Mobile phone users want to not only quickly connect to emergency services, but also have the ability to request police or other emergency assistance to their specific location (especially when the user's location is unknown to the user). Accordingly, emergency number and location services are now in place in progressive mobile networks. Governments also have an interest in insuring that emergency services can find the caller of the emergency number.
To accelerate the rate at which mobile networks incorporate emergency numbers in their systems, in the United States the Federal Communications Commission (FCC) has recently promulgated requirements relating to emergency numbers in mobile networks. Among these requirements is that the mobile network provider be able to locate a cell phone within about ten meters of the mobile phone's true location, when an emergency number is dialed, about 67% of the time. Other governments are implementing similar rules. To comply with these government mandates, cellular telephone service providers utilize a number of methods to locate cell phones.
Some methods of calculating the location of a mobile phone measure the time it takes for a signal to travel between a predetermined number of points in the mobile network. One method of locating a cell phone using time measurements is called the Uplink Time of Arrival (TOA) method.
The Uplink Time of Arrival method is based on measuring the time of arrival of a known signal sent from a mobile phone and received by at least three different base stations. The TOAs at different base stations are calculated and transmitted to a Mobile Positioning Center (MPC). Because of the unknown transmission time of the mobile, the MPC calculates time-difference-of-arrivals (TDOA) by pair-wise subtracting the TOA values. The mobile position can then be calculated via hyperbolic trilateration.
Handover Timing Advance (HTA) provides another method of using timing advance to locate a mobile phone. In a Time Division Multiple Access (TDMA) system the time it takes a signal to travel between the mobile phone and the servi
Havinis Theodore
Papadimitriou Dimitrios
Ericsson Inc.
Milord Marceau
Navarro Arthur I.
Urban Edward F.
LandOfFree
Priority handling of location services in a mobile... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Priority handling of location services in a mobile..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Priority handling of location services in a mobile... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2869071