Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via time channels
Reexamination Certificate
1997-11-26
2001-03-27
Olms, Douglas (Department: 2661)
Multiplex communications
Communication techniques for information carried in plural...
Combining or distributing information via time channels
C370S311000
Reexamination Certificate
active
06208668
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to communication systems and more specifically but not limited to methods and corresponding apparatus for acquiring an operating channel.
BACKGROUND OF THE INVENTION
Communications systems, and specifically messaging and paging systems, typically communicate on a channel using signals having a specified radio frequency. In normal operation messaging systems utilize a scheduled channel protocol where the system and a selective messaging unit by virtue of operating on the system know a predetermined time where communication is possible. This scheduled channel protocol facilitates battery savings since the unit or most of the circuitry in the unit is inactive or asleep most of the time. These systems operate as long as the channel or signal can be reliably received by selective messaging units operating within the system. Where the signal strength of the channel received by the selective messaging unit falls below a sensitivity level, the selective messaging unit will lose that channel.
Subsequently, the selective messaging unit will typically attempt an energy search to identify one or more channels with an appropriate signal. This energy search will ordinarily include the original channel lost, or may include other additional channels. Energy searches require the receive circuitry of the selective messaging unit to be active and tuned to the proper frequency. While active, this circuitry tends to require large amounts of energy or power relative to that required in an inactive state, and this power must be supplied from a very limited energy source such as a battery.
After the operating channel is lost, the selective messaging unit must rely on an internal clock and its accuracy for a time reference that will usually vary from the system time reference. Thus the selective messaging unit must do an energy search relatively often to acquire or re-acquire an operating channel in a reasonable period of time. Though design trade-offs can be made between the frequency of searches and the time required to obtain a viable operating channel versus the limited energy source, user expectations normally mitigate in favor of finding a channel rapidly and battery life ends up suffering.
Clearly a need exists to more effectively allow a selective messaging unit to acquire an operating channel while minimizing battery usage.
REFERENCES:
patent: 4804954 (1989-02-01), Macnak et al.
patent: 5910944 (1999-06-01), Callicotte et al.
patent: 5940431 (1999-08-01), Haarsten et al.
patent: 6009319 (1999-12-01), Khullar et al.
patent: 6016312 (2000-01-01), Storm et al.
patent: 6023477 (2000-02-01), Dent
patent: 6029061 (2000-02-01), Kohlschmidt
Breeden R.. Louis
Motorola Inc.
Nguyen Brian
Olms Douglas
LandOfFree
Apparatus and method for acquiring an operating channel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for acquiring an operating channel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for acquiring an operating channel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2532407