Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
1998-08-11
2002-01-15
Urban, Edward F. (Department: 2683)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S524000, C370S311000
Reexamination Certificate
active
06339713
ABSTRACT:
DESCRIPTION OF RELATED ART
Mobile wireless communication is becoming increasingly important for safety, convenience, and efficiency. One prominent mobile communication option is cellular communication. Cellular phones, for instance, can be found in cars, briefcases, purses, and even pockets. As cell phones have become smaller for improved portability, battery size and weight has become a critical barrier to further cell phone miniaturization. One technique to limit the required size and weight of batteries is to reduce the power demands placed on them. Consequently, cell phone portability (as well as standby and talk time) can be improved through power management.
In wireless communications systems, procedures for establishing communication and transmitting messages between mobile terminals and base stations are defined. For instance, when a mobile terminal wishes to transmit a message or set-up a phone call, the mobile terminal must establish communication with a proximate base station.
Referring to
FIG. 1A
, a cell in a mobile communications system is diagramed at
100
. In cell
100
, two mobile terminals are attempting to establish a connection with a base station
110
. A mobile terminal
120
is “attempting to secure a random access channel” (ASRAC) via ASRAC120 to the base station
110
, and a mobile terminal
130
is attempting to secure a random access channel via ASRAC130 to the base station
110
(i.e., “random” access). The transmission ASRAC120 is received and processed prior to the transmission ASRAC130 in this example. The phrase “attempting to secure a random access channel” is also termed “attempting to establish a connection” (e.g., with a base station) within this document.
Referring to
FIG. 1B
, cell
100
is illustrated where the base station
110
is busy establishing a connection with and receiving a message from the mobile terminal
120
. A downlinked control channel message
140
initially includes a response code that corresponds to the mobile terminal
120
and constantly includes information indicating that the base station
110
is busy (e.g., a “B”). Note that for diagrammatical clarity thin arrows represent point-to-point transmissions while thick arrows represent point-to-multipoint transmissions, such as from the base station
110
to all mobiles within cell
100
.
The mobile terminal
130
receives and processes the information in the downlink control channel message
140
. The mobile terminal
130
must continue to monitor the downlinked control channel message
140
until the busy indication “B” is changed. Unfortunately, this monitoring consumes battery power in the mobile terminal
130
. Note that although the mobile terminals
120
and
130
are represented as vehicles, this is primarily to represent their mobility. In fact, the mobile terminals
120
and
130
may be hand-held devices in which battery life is a critical feature to users.
Continuing now with
FIG. 1C
, a cell
100
is illustrated where a base station is idle and available for an attempt to establish a connection with a new mobile terminal. Once the base station
110
has completed the communication with the mobile terminal
120
, the base station
110
transmits a downlink control channel message
150
with an idle indication “I”. The mobile terminal
130
detects the idle indication “I” and responds with another ASRAC130 to establish a connection with the base station
110
. The mobile terminal
130
can then complete the useful process of transmitting its message.
In contrast to the useful connection establishment and message transmittal procedure diagramed in
FIG. 1C
, the mobile terminal
130
is achieving no useful purpose while it consumes energy in FIG.
1
B. The mobile terminal
130
is monitoring the downlink control channel messages
140
to detect when the indication switches from “B” for busy to “I” for idle. This monitoring consumes power and can last for an extended amount of time when, for example, the mobile terminal
120
in
FIG. 1B
is transmitting a lengthy message.
In summary, mobile terminals in the prior art have heretofore been required to expend battery power while monitoring a downlinked communication from a base station when they wish to establish a connection with the base station and the multiple access channel is currently busy.
SUMMARY OF THE INVENTION
The system and method of the present invention, which belongs to the field of power management for extending the useful battery life of mobile terminals in wireless communications systems, enables mobile terminals to reduce power while waiting for a shared multiple access channel to become available. In accordance with the present invention, a base station transmits information that indicates the amount of time remaining until a current occupier of the shared multiple access channel will complete its message.
Traditionally, when a second mobile terminal wishes to transmit a message over a shared multiple access channel that is currently occupied by a first mobile terminal, the second mobile terminal constantly monitors the shared multiple access channel downlink in order to detect when the channel switches from busy to idle. This constant monitoring squanders battery power and, therefore, contributes to large battery requirements and unnecessarily reduces the standby and conversation time of the second mobile terminal.
According to the present invention, during a message transmission of the first mobile terminal, the base station transmits, in addition to a busy indication, a number of remaining units that corresponds to the number of units remaining until completion of the first mobile terminal's message. When the second mobile terminal checks the multiple access channel downlink because it wishes to transmit its own message, the second mobile terminal will detect both an busy indication and the number of remaining units.
Consequently, the second mobile terminal can then cease monitoring the channel until the specified number of remaining units has transpired. Afterwards, the mobile terminal can again check the channel to determine whether the channel is indicated as idle. By ceasing the constant monitoring of the multiple access channel downlink, the second mobile terminal conserves power and thus extends the useful life of the battery.
An important technical advantage of the present invention is that it provides power management features for mobile terminals in wireless communications systems.
Another important technical advantage of the present invention is that it provides power management features for mobile terminals during random access procedures.
Yet another important technical advantage of the present invention is that it transmits durational indicators that inform mobile terminals of the time remaining until completion of a current message transmission procedure.
Yet another important technical advantage of the present invention is that it enables mobile terminals to conserve power while awaiting an idle random access channel by obviating any need to constantly monitor a busy/idle condition.
Yet another important technical advantage of the present invention is that it provides a system and method that can be implemented for new mobile terminals without interfering with the functioning of existing mobile terminals.
The above-described and other features of the present invention are explained in detail hereinafter with reference to the illustrative examples shown in the accompanying drawings. Those skilled in the art will appreciate that the described embodiments are provided for purposes of illustration and understanding and that numerous equivalent embodiments are contemplated herein.
REFERENCES:
patent: 5175870 (1992-12-01), Mabey
patent: 5193209 (1993-03-01), Maeda et al.
patent: 5230084 (1993-07-01), Nguyen
patent: 5594738 (1997-01-01), Crisler et al.
patent: 6049532 (2000-04-01), Steele et al.
patent: 6049724 (2000-04-01), Rozenblit et al.
patent: 6058289 (2000-05-01), Gardner et al.
patent: 0 462 572 (1991-12-01), None
patent: 0 652 680 (1995-05-01), None
patent: 0
Hansson Rolf
Herlitz Anders
Jenkens & Gilchrist. PC
Telefonaktiebolaget LM Ericsson
Urban Edward F.
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