Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
1997-06-26
2001-04-24
Nguyen, Lee (Department: 2683)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S062000, C455S161100, C455S419000, C455S432300, C455S435100
Reexamination Certificate
active
06223042
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to wireless communications and, more particularly, to the selection of a particular service provider in a multi service-provider environment.
BACKGROUND OF THE INVENTION
In a multi service-provider wireless communication environment, such as a cellular network, multiple service providers may operate in a given geographic area, for example, a metropolitan area. Each service provider will have its own “geographic network” in that area, and will be assigned a unique operational “frequency” (which may comprise multiple frequencies, or a frequency band) for that geographic area. The service providers may have other geographic networks in other geographic areas. However, in those other geographic areas the service providers may be assigned different operational frequencies.
The invention relates to how a subscriber's cellular phone selects, and “registers onto”, a particular range of operating frequencies (or “frequency band”), such as, for example, the frequency band assigned to the subscriber's selected service provider, in the geographic area in which the subscriber's cellular phone happens to be located and operating. (In this patent, the term “cellular phone” refers to a wireless, mobile phone that operates in a multi service-provider environment, usually a cellular environment. The term “registers onto” includes not only the processes involved in establishing a call, but also includes any communication between the network and wireless communication device, such as, for example, when the device is in standby mode. In particular, these “registrations” may give the network information, for example, on the location of the device.)
In early versions of cellular phones, the subscriber's phone would be pre-programmed so that on being turned on, i.e., “powered-up”, the phone would operate at a pre-selected band, or would implement a pre-programmed search schedule to find a particular operating frequency band in accordance with the pre-programmed schedule. For example, the schedule might call for seeking service on a particular band and, if no service could be found on that band, the schedule might call for seeking service from non-preferred providers located on other bands. In later devices the pre-programmed schedule in the phone could be manually altered by the user.
However, it should be recognized that in these early implementations the number of possible bands were few and there were only a small set of hailing frequencies, sometimes called “control frequencies”. Accordingly, in implementing a search schedule, all of the control channels could be scanned in a relative short period of time. However, as many more frequencies became available, many more control channels would have to be scanned to implement search schedules. This is a time consuming process, and consumers will not tolerate the associated delay on power up.
To address this intensified problem of searching rapidly for available appropriate frequencies, more efficient search protocols were devised to enable the subscriber's phone to search, efficiently and rapidly, through the various available operational frequencies for one assigned to the subscriber's service provider, or, in the absence of its service provider in the specific geographic area, for one assigned to a service provider with whom the subscriber's service provider had a “partnering” arrangement. (Such protocols usually have to be implemented whenever the phone is powered-up, even when in its home area, because the phone does not know that it is in its home area until it has found a channel that is broadcasting its home area identities. However, since the purpose of such search protocols is to enable more effective roaming operation, the protocols are called “roaming” schedules, even though they are most often implemented in the subscriber's home area, where the subscriber is not technically “roaming”. It should be noted that with the ability to “roam”—i.e., operate outside one's home area, the “wireless network” is broadened to include all networks on which the subscriber may get service.)
This invention involves “intelligent roaming”—improved techniques for subscriber selection of an optimum service provider when the subscriber's phone is powered-up, whether in the subscriber's home area or while roaming. The invention is an improved technique for intelligent roaming and is best understood in the context of the frequency band allocation used in current wireless communications.
FIG. 1
illustrates a portion of the radio frequency spectrum used today in such wireless communications. Frequency range
10
, centered around 800 MHz, has historically been known as the cellular frequency range. Frequency range
12
, centered about 1900 MHz, is a more recently established frequency range associated with personal communication services (PCS). Each range of frequencies, i.e., the cellular and PCS, are broken into two portions; an uplink portion, that is used for communications from a mobile communication device to a base station such as a cellular base station, and a downlink portion, that is used for communications from the base station to a mobile communication device. In cellular frequency range
10
, the uplink portion is labeled
14
, and the downlink portion is labeled
16
. In the PCS frequency range,
12
, the uplink portion is labeled
18
and the downlink portion is labeled
20
.
Each of the frequency ranges is broken into bands which are typically associated with different service providers. For example, in the U.S., the FCC has allocated frequencies and frequency bands within its jurisdiction as described in the present application. But other nations, for example the UK or China, may have regulators that have determined a different frequency allocation for their cellular and PCS bands. In the case of cellular frequency range
10
, frequency bands
30
and
32
are designated band “a” for uplink and downlink communications, respectively. In a particular geographic area, a cellular service provider is assigned frequency band “a” for use in mobile communications. Likewise, in the same geographic area another cellular service provider is assigned frequency bands
34
(uplink) and
36
(downlink) which are designated band “b”. The frequency ranges assigned to the two service providers are sufficiently separated so as to not interfere with each other, thereby enabling the two separate service providers to offer service in the same geographic area.
Recently, the US Government auctioned the PCS frequency spectrum to service providers. As with the cellular frequency range, the PCS frequency range is broken into several bands with different service providers licensed to use different frequency bands within a particular geographical area. The PCS bands are referred to as A, B, C, D, E and F. The A band includes uplink band
50
and downlink band
52
. The B band includes uplink band
54
and downlink band
56
. Band C includes uplink band
58
and downlink band
60
. Each uplink and downlink band of the A, B and C bands is approximately 30 MHz wide. The D band includes uplink band
62
and downlink band
64
. The E band includes uplink band
66
and downlink band
68
. Likewise, band F includes uplink band
70
and downlink band
72
. The uplink and downlink bands of bands D, E and F are approximately 10 MHz wide each. It should be noted that in the combined cellular and PCS frequency bands, it is possible to have as many as eight different wireless communication service providers in a particular area.
Each of the different cellular and PCS bands consist of control channels and communication channels in both the uplink and downlink direction. In the case of analog cellular bands, there are
21
control channels for both the “a” and “b” bands. Each of the control channels include an uplink and a downlink portion. The control channels transmit information such as a SOC (System Operator Code), a SID (System Identifier Code), paging information, call setup informatio
AT&T Wireless Services Inc
Nguyen Lee
LandOfFree
Method of intelligent roaming using network information does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of intelligent roaming using network information, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of intelligent roaming using network information will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2449917