Adaptive rate channel scanning method for TDMA wireless communications
AssigneeEricsson Inc.
InventorHong Shi
Life of this patent
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Abstract
An apparatus and method for adaptive channel scanning in a TDMA radio communication system (100) allows a mobile station (106) to respond to the operating environment of the radio communication system. The mobile station or handset detects the operating environment of the handset and adjusts a scan rate interval (SRI) (412) in response to the operating environment. After the scan rate interval has elapsed, the handset scans one of the predetermined subset of channels and a full set of channels of the plurality of radio channels.
Claims18
A channel scanning method for a radio communication system having a plurality of frequency carriers with a plurality of radio channels, the method comprising:
- (a) detecting an operating environment of a handset in the radio communication system;
- (b) setting a scan rate interval and a short scan indicator in response to said operating environment, wherein the scan rate interval is used to control the duration of a scan interval and the short scan indicator is used to determine the number of said plurality of frequency carriers scanned by said handset and the value of the scan rate interval and the value of the short scan indicator are dynamically adjusted in response to said operating environment;
- and
- (c) based on the value of said short scan indicator, scanning either the plurality of frequency carriers or a predetermined subset of said plurality of frequency carriers for channels that are available in said plurality of radio channels for use by said handset.
A channel scanning method for a radiotelephone operable in a time division multiple access radio communication system having a plurality of frequency carriers with a plurality of radio channels, the method comprising:
- waiting for lapse of a channel scan timer;
- determining a value for the short scan indicator in response to a number of listen before talk (LBT) channels available on said plurality of frequency carriers;
- in response to the short scan indicator having a first value, performing a scan of a limited set of said plurality of frequency carriers for channels that are available in said plurality of radio channels;
- and
- in response to the short scan indicator having a second value, performing a scan of said plurality of frequency carriers for channels that are available in said plurality of radio channels.
A radiotelephone comprising:
- a clock;
- a receiver tunable to a plurality of frequency carriers with a plurality of radio channels;
- and
- a controller coupled to the receiver to control tuning of the receiver and coupled to the clock to establish a channel scan timer for controlling the time between scans of the plurality of frequency carriers for channels that are available in said plurality of radio channels by the receiver, the controller adjusting a duration of the channel scan timer in response to a number of listen before talk (LBT) channels detected by the receiver, and wherein the controller is configured to adjust the duration of the channel scan timer to a maximum value when a substantial number of LBT channels are available on said plurality of frequency carriers near a predetermined frequency band edge.
Dependencies are inferred from the claim text.