EP0454638A1
Expired / Lapsed
EP
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A method for handoff in a mobile radio communication system
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1991-02-18
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Granted: —
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Expires: 2011-02-18
Abstract
Abstract The invention relates to a method in connection with handoff from a first base station (1) in a mobile radio communication system, in which method the signal strengths from a set of base stations (1) surrounding a mobile station are measured in the latter. When handoff is considered to be motivated, the signal strength vector formed by the measured signal strengths is correlated with stored characteristic signal strength vectors associated with the first base station (1). If the correlation between measured signal strength vector and one of said stored characteristic signal strength vectors exceeds a predetermined correlation level, handoff is commanded to a predetermined second base station (2-7) in the set having acceptable but not the highest signal strength in the measured signal strength vector, or is the handoff procedure interrupted and the connection between the mobile station and the first base station (1) maintained.
Inventors
- 👤 Per Viktor Israelsson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 15:08
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/24; H04W36/32; H04W36/322
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
148 words
A method for handoff from a first base station (1) in a mobile radio communication system, in which signal parameters that describe signals between a mobile station (MS) and a set of base stations (1-7) surrounding this mobile station are measured and used for handoff decisions, characterized in that, (a)when handoff is considered to be motivated, the signal parameter vector formed by the measured signal parameters is correlated with stored characteristic signal parameter vectors (SS_1, ..., SS_7) associated with said first base station (1), and, (b)if the correlation between the measured signal parameter vector and one of said stored characteristic signal parameter vectors (SS_1. ..., SS_7) exceeds a predetermined correlation level, (b1) handoff is ordered to a predetermined second base station (2-7) in said set, or (b2) the handoff procedure is interrupted and the connection between the mobile station (MS) and said first base station (1) is maintained.
Claim 2
Dependent Claim
40 words
The method of claim 1, characterized in that the signal parameters comprise at least one of the signal strengths (SS_1 - SS_7) of signals transmitted from the base stations (1-7) in the set as measured at the mobile station (MS).
Claim 3
Dependent Claim
84 words
The method of claim 1 or 2, characterized in that said signal parameters comprise at least one of: - the bit error rate (BER) of signals transmitted from at least one base station (1-7) in the set; - the time dispersion (TD) of signals transmitted from at least one base station (1-7) in the set; and - the ratio (C/I) between the signal strength of the carrier that has been transmitted from at least one base station (1-7) in the set and interfering signals.
Claim 4
Dependent Claim
37 words
The method of claim 1, characterized in that said signal parameters comprise at least one of the signal strengths measured at the base stations (1-7) in the set of a signal transmitted by said mobile station (MS).
Claim 5
Dependent Claim
104 words
The method of claim 1 or 4, characterized in that said signal parameters comprise at least one of: - the bit error rate (BER) of a signal transmitted by said mobile station (MS) as measured at at least one base station (1-7) in the set; - the time dispersion (TD) of a signal transmitted by said mobile station (MS) as measured at at least one base station (1-7) in the set; and - the ratio (C/I) between the signal strength of the carrier transmitted by said mobile station (MS) and interfering signals as measured at at least one base station (1-7) in the set.
Claim 6
Independent Claim
38 words
The method of any of claims 2 - 5, characterized in that handoff in step (b) is ordered to a base station (2-7) having an acceptable but not the highest signal strength in the measured signal parameter vector.
Claim 7
Independent Claim
38 words
The method of any of the preceding claims, characterized in that said characteristic signal parameter vectors (SS_1, ..., SS_7) that are associated with said first base station (1) are stored in the unit (MSC) that makes handoff decisions.
Claim 8
Dependent Claim
56 words
The method of claim 7, characterized in that said characteristic signal parameter vectors (SS_1, ..., SS_7) are stored as records in a data file, in which each record comprises a data field with an identification code for a base station and data fields for signal parameters of characteristic signal parameter vectors associated with this base station.
Claim 9
Dependent Claim
30 words
The method of claim 7, characterized in that said unit (MSC) making handoff decisions stores characteristic signal parameter vectors for all the base stations that are connected to said unit.
References Cited (Backward Citations)
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