Method and apparatus for determining coverage and switching between overlay communication systems
First Claim
1. A method of switching a terminal from a first wireless cdma communication system to a second cdma wireless communication system, comprising:
- obtaining at least one measurement of at least one parameter for at least one base station in the first cdma communication system;
deriving a metric based on the at least one measurement;
determining whether or not the terminal is within coverage of the first cdma communication system based on the metric; and
initiating a switch to the second cdma communication system if the terminal is deemed to be outside the coverage of the first cdma communication system, wherein said metric is derived using one of the following formulae;
(a) metric=Sum of EC/I0 of all pilots in the active and candidate sets and Max {EC/I0 of pilots inthe neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference,(b) metric=Sum of EC/I0 of all pilots in the active set and Max {EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference,(c) metric=Max {sum of EC/I0 of pilots in the active set, EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, and(d) metric=Max {EC/I0 of pilots in the active, candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference.
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Accused Products
Abstract
Techniques to determine whether or not a terminal is under the coverage of a current wireless communication system (e.g., a packet data system) and to switch from the current system to another wireless communication system (e.g., a voice/data system). In one method, at least one measurement of at least one parameter for at least one base station in the current system is initially obtained. The measurement(s) may be SNR measurements. A metric is derived based on the measurement(s) and used (typically along with a metric threshold and a timer) to determine whether or not the terminal is within the coverage of the current system. A switch to another system is initiated if the terminal is deemed to be outside the coverage of the current system. The two systems provide at least one common service (e.g., packet data service).
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Citations
38 Claims
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1. A method of switching a terminal from a first wireless cdma communication system to a second cdma wireless communication system, comprising:
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obtaining at least one measurement of at least one parameter for at least one base station in the first cdma communication system; deriving a metric based on the at least one measurement; determining whether or not the terminal is within coverage of the first cdma communication system based on the metric; and initiating a switch to the second cdma communication system if the terminal is deemed to be outside the coverage of the first cdma communication system, wherein said metric is derived using one of the following formulae; (a) metric=Sum of EC/I0 of all pilots in the active and candidate sets and Max {EC/I0 of pilots inthe neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, (b) metric=Sum of EC/I0 of all pilots in the active set and Max {EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, (c) metric=Max {sum of EC/I0 of pilots in the active set, EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, and (d) metric=Max {EC/I0 of pilots in the active, candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A terminal comprising:
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a metric computation unit operative to receive at least one measurement of at least one parameter for at least one base station in a first cdma wireless communication system and to derive a metric based on the at least one measurement; a coverage determination unit operative to determine whether or not the terminal is within coverage of the first cdma communication system based on the metric; and a controller operative to initiate a switch to a cdma second wireless communication system if the terminal is deemed to be outside the coverage of the first cdma communication system, wherein said metric is derived using one of the following formulae; (a) metric=Sum of EC/I0 of all pilots in the active and candidate sets and Max {I EC/I0 of pilots in the neighbor sets}. wherein said EC represents energy-per-chip, and I0 represents noise and interference, (b) metric=Sum of EC/I0 of all pilots in the active set and Max {EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference (c) metric=Max {sum of EC/I0 of pilots in the active set, EC/I0 of pilots in the candidate and neighbor sets}. wherein said EC represents energy-per-chip, and I0 represents noise and interference, and (d) metric=Max {EC/I0 of pilots in the active, candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference. - View Dependent Claims (21, 22, 23, 24, 25)
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26. An apparatus comprising:
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means for obtaining at least one measurement of at least one parameter for at least one base station in a first cdma wireless communication system; means for deriving a metric based on the at least one measurement; means for determining whether or not the terminal is within coverage of the first cdma communication system based on the metric; and means for initiating a switch to a second wireless communication system if the terminal is deemed to be outside the coverage of the first cdma communication system, wherein said metric is derived using one of the following formulae; (a) metric=Sum of EC/I0 of all pilots in the active and candidate sets and Max {EC/I0 of pilots in the neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, (b) metric=Sum of EC/I0 of all pilots in the active set and Max {EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference (c) metric=Max {sum of EC/I0 of pilots in the active set, EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, and (d) metric=Max {EC/I0 of pilots in the active, candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference. - View Dependent Claims (27, 28, 29)
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30. A memory communicatively coupled to a digital signal processing device (DSPD) capable of interpreting digital information to:
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receive at least one measurement of at least one parameter for at least one base station in a first cdma wireless communication system; derive a metric based on the at least one measurement; determine whether or not a terminal is within coverage of the first cdma communication system based on the metric; and initiate a switch to a second cdma wireless communication system if the terminal is deemed to be outside the coverage of the first cdma communication system, wherein said metric is derived using one of the following formulae; (a) metric=Sum of EC/I0 of all pilots in the active and candidate sets and Max {EC/I0 of pilots in the neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, (b) metric=Sum of EC/I0 of all pilots in the active set and Max {EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, (c) metric=Max {sum of EC/I0 of pilots in the active set, EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, and (d) metric=Max {EC/I0 of pilots in the active, candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference. - View Dependent Claims (31, 32, 33)
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34. A method of determining coverage for a terminal in a wireless communication system, comprising:
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obtaining at least one signal quality measurement for at least one base station in the wireless communication system; deriving a metric based on a maximum of the at least one signal quality measurement; and determining whether or not the terminal is within coverage of the wireless communication system based on the metric, wherein said metric is derived using one of the following formulae; (a) metric=Sum of EC/I0 of all pilots in the active and candidate sets and Max {EC/I0 of pilots in the neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference (b) metric=Max EC/I0 of pilots in the active, candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference (c) metric=Sum of EC/I0 of all pilots in the active set and Max {EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference, and (d) metric=Max sum of EC/I0 of pilots in the active set, EC/I0 of pilots in the candidate and neighbor sets}, wherein said EC represents energy-per-chip, and I0 represents noise and interference. - View Dependent Claims (35, 36, 37, 38)
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Specification