Method and apparatus for a deep-sleep mode in a digital cellular communication system

• US 5,590,396 A
• Filed: 04/20/1994
• Issued: 12/31/1996
• Est. Priority Date: 04/20/1994
• Status: Expired due to Term

• Current Assignee: Erisson GE Mobile Comm Incorporated
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Henry, Raymond C.
• Primary Examiner(s): Urban, Edward F.
• Application Number:
  US08/231,000
• Time in Patent Office: 986 Days
• Field of Search: 455/33.1, 455/38.3, 455/54.1, 455/56.1, 455/343, 455/30, 379/59
• US Class Current: 455/426.1
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and apparatus is provided for extending the battery life of a cellular radiotelephone. A cellular radiotelephone is conditioned to operate in a pager-only mode wherein the radiotelephone may receive short messages from a base station while conserving battery life by cyclically adopting a deep-sleep state. The base station is notified by the radiotelephone before the radiotelephone enters the deep-sleep state that the radiotelephone is unable to receive messages. After a period of time, the radiotelephone wakes-up, re-establishes contact with the base station and notifies the base station that the radiotelephone is ready to receive messages. After receipt of any messages the radiotelephone repeats the process.

Claims

1. In a cellular radio communication system including a base station with a base station control signal, said control signal having a plurality of paging classes numbered 1 through N, said paging classes corresponding to lengths of time between paging time slots during which paging information is broadcast, and at least one mobile station conditioned to receive paging information broadcast by the base station during said paging time slots corresponding to a particular paging class assigned to the mobile station by the base station, said mobile station further having a regular sleep mode wherein a first set of selected circuits are deactivated and a deep sleep mode wherein a second set of selected circuits are deactivated, a method for saving battery power in the mobile station, comprising the steps of:

(a) placing the mobile station into a page only mode;

(b) transmitting a first signal from the mobile station to the base station indicating that the mobile station is unable to receive messages from the base station;

(c) entering said deep-sleep mode by deactivating said first set and said second set of selected circuits within the mobile station for a predetermined period of time;

(d) automatically entering said regular sleep mode by reactivating said second set of selected circuits within the mobile station after said predetermined time period;

(e) reactivating said first set of selected circuits and receiving by the mobile station the base station control signal and transmitting from the mobile station a second signal indicating that the mobile station is able to receive said messages;

(f) transmitting from the base station said messages on a set of said plurality of time slots of the base station control signal;

(g) monitoring by the mobile station said messages on said set of said plurality of time slots of the base station control signal; and

(h) repeating steps (b) through (g) until said mobile station is reset from said page only mode.

2. The method of claim 1, wherein said predetermined period of time is longer than the longest paging class.

3. The method of claim 1, wherein said second set of selected circuits includes a temperature controlled crystal oscillator.

4. The method of claim 1, wherein said deep sleep mode reduces the average current drain from as compared to the regular sleep mode.

5. The method of claim 1, wherein said predetermined period of time is determined by the mobile station.

6. The method of claim 1, wherein said first signal includes a power-down registration message.

7. The method of claim 1, wherein said second signal includes a power-up registration message.