Telecommunications – Transmitter and receiver at separate stations – Plural transmitters or receivers
Reexamination Certificate
1999-02-26
2001-08-14
Maung, Nay (Department: 2744)
Telecommunications
Transmitter and receiver at separate stations
Plural transmitters or receivers
C455S070000, C455S574000
Reexamination Certificate
active
06275712
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to mobile station control states and, more particularly, to a method and apparatus for transitioning a mobile station between packet data service control states based on available power at the mobile station.
BACKGROUND OF THE INVENTION
Major cellular system types include those operating according to the Global System for Mobile Communication (GSM) standard, the TIA/EIA/IS-95 Mobile Station-Base Station Compatibility Standard for Dual Mode Wide Band Spread Spectrum Cellular System (IS-95A), the TIA/EIA/IS-136 Mobile Station-Base Station Compatibility Standard (IS-136), and the TIA/EIA 553 Analog Standard (AMPS/TACS). Other major cellular systems include those operating in the personal communications system (PCS) band according to the ANSI-J-STD-008 1.8-2.0 GHz standard or those operating according to the GSM-based PCS 1900 (1900 MHz frequency range) standard. IS-95A is currently being updated as IS-95B in the document TIA/EIA-3693.
Currently, each of the major cellular system standards bodies is implementing data services into its digital cellular specifications. A packet data service specification has been finalized for GSM and IS-95A. Packet data service specifications compatible with the IS-136 and IS-95B standards are also being prepared.
A third-generation CDMA system is also being developed to provide more sophisticated and improved data services than provided by IS-95 and eventually to replace IS-95. In the proposed standard for third-generation CDMA, known as cdma2000 ITU-R RTT, it has been proposed that third-generation systems include packet data services that utilize one or more control states that a mobile station may be in when engaged in a data service. The control states are states in which a mobile station can have varying physical and logical channel configurations assigned to it, depending on the present data transmission situation. The third-generation CDMA control states are intended to be utilized when packet data services for particular mobile stations have varying quality of service (QoS) requirements.
For example, when no data has been transmitted for a certain period of time, a mobile station may transition from an active state, in which dedicated forward and reverse control and traffic channels are each maintained, to a control hold state in which only a dedicated forward control channel is maintained. The control hold state allows fast reassignment through the forward control channel and frees up system traffic channel resources. Again, after a certain period of time in the control hold state when no data has been transmitted, the mobile station may transition from the control hold state to a suspended state. In the suspended state, all dedicated channels are released and the mobile station monitors only the forward common control channel. From the suspended state, the mobile station may transition back to the control hold state if it is determined that data is to be transmitted within a certain period of time, or the mobile may transition to a null state if data is not to be transmitted within a certain period of time. Each of the control states requires the mobile station to expend a certain amount of power that depends on the type of channels assigned in that state and the time spent in that state. QoS requirements may be used to determine the time period for transitioning between control states and to determine which states are allowable for a mobile station. By defining the time periods and allowable states in a particular way, a mobile station may have faster access to channel resources and less delay in its packet application to satisfy certain QoS requirements while minimizing power consumption and freeing up system resources. While QoS requirements may be the major factor in determining the transition periods and allowable control states, basing the transition periods and allowable control states solely on QoS requirements may not be the most efficient way of controlling transitions between control states.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus for transitioning a mobile station between control states in a telecommunications system based on available power at the mobile station. The method and system allows a mobile station to signal the system to indicate that power available to the mobile station is less than or greater than a predetermined threshold and that parameters for controlling transitions between control states should be adjusted accordingly. For example, if a mobile station battery power falls below a predetermined threshold, the time periods for triggering transitions from selected control states that require greater mobile station power expenditure to maintain may be decreased, or the mobile station may be controlled to transition immediately from a current state to another state. The system may trade off packet service delay with mobile station power expenditure to prolong useful life of a battery in the mobile station. If the battery is charged and available power rises again above the predetermined threshold, the time periods for triggering transitions from the selected control states may be increased, or certain states prohibited in a low-power condition may become allowable again.
In an embodiment of the invention, the method and apparatus is implemented in a system having packet data service with states including an active state, a suspended state and a control hold state. The active state is associated with a timer Tactive, and the control hold state is associated with a timer Thold. The timer associated with each state is activated upon the termination of each data transmission and determines how long a mobile station will remain in that state if no data is transmitted or received within the time period duration for which the timer runs. According to the embodiment, a mobile station involved in transmitting and receiving data through the packet service transmits an indication to the system that the mobile station's battery power has fallen below or risen above a predetermined threshold level of full charge, for example, X%, in order to allow the system to modify the time period durations for Tactive and Thold. Tactive and Thold may be set to initial values used for a battery having full power.
Upon receiving the indication from the mobile station that battery power has fallen below X%, the system may then decrease the time period duration for the Tactive and Thold timers. As the mobile station is involved in the packet data service and data transmission ceases for periods of time, the mobile station will spend less time in the active and control hold states and more time in the suspended state. This preserves the remaining battery power.
If the mobile station has access to additional power during the packet data service, for example, the mobile station is plugged into a charger, the mobile station may transmit an indication to the system that the mobile station's battery power has risen again above the threshold level, X%. The system may then restore the time period duration for the Tactive and Thold timers to the initial settings.
REFERENCES:
patent: 4449248 (1984-05-01), Leslie et al.
patent: 5241542 (1993-08-01), Natrajan et al.
patent: 5794137 (1998-08-01), Harte
patent: 5870685 (1999-02-01), Flynn
patent: 5949484 (1999-09-01), Nakaya et al.
patent: 6072784 (2000-06-01), Agrawal et al.
“A Battery Power Level Aware MAC Protocol for CDMA Wireless Networks,” Shalinee Kishore, Et Al.
The cdma2000 ITU-R-RTT Candidate Submission (0.18), Telecommunications Industry Association, vol. 12, Jul. 27, 1998, pp. 117-139.
Fry George
Gray Steven D.
Maung Nay
Nokia Mobile Phones Ltd
Rivers Brian T.
LandOfFree
Mobile station control states based on available power 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 station control states based on available power, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mobile station control states based on available power will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2543898