EP0472511A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Handoff of a mobile station between half rate and full rate channels
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1991-08-21
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Granted: —
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Expires: 2011-08-21
Abstract
Abstract In a cellular mobile telephone system of the type having TDMA channels, a plurality of mobile station operate at either a full rate or a half rate. If the mobile stations are operating on the periphery of a cell they are assigned to full rate channels. If the mobile stations are operating in the vicinity of the base station, they are assigned to half rate channels. The mobile station are reassigned from full rate to half rate channels depending upon a measured parameters relating to signal strength or quality, such as the bit error rate of communications between the mobile station and the base station. If the measured bit error rate between the mobile station and a neighboring station is less than the bit error rate between the mobile station and its presently assigned base station, the mobile station is handed off to the neighboring base station.
Inventors
- 👤 Jan Erik Uddenfeldt
- 👤 Hans Frank Hermansson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 17:41
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/0001; H04L1/0002; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2643; H04L1/20; H04L1/208; H04W; H04W36/00; H04W36/24; H04W36/30; H04W36/304; H04W36/06
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
99 words
A method of communication and handoff in a cellular mobile radio system having a plurality of base stations for communication with a plurality of mobile stations in the cells, comprising the steps of: transmitting a signal between a first base station and at least a first mobile station; estimating periodically the quality of the received signal; setting the transmission rate of the signal to a half rate if the estimated quality is below a first predetermined value; and setting the transmission rate of the signal to a full rate if the estimated quality is above the first predetermined value.
Claim 2
Independent Claim
99 words
A method of communication and handoff in a cellular mobile radio system having a plurality of base stations for communication with a plurality of mobile stations in the cells, comprising the steps of: transmitting a signal between a first base station and at least a first mobile station; estimating periodically the quality of the received signal; setting the transmission rate of the signal to a half rate if the estimated quality is below a first predetermined value; and setting the transmission rate of the signal to a full rate if the estimated quality is above the first predetermined value.
Claim 3
Dependent Claim
67 words
A method according to claim 1 which further includes the steps of: estimating periodically the quality of the received signal at a second base station; and handing off the first mobile station from the first base station to the second base station if the estimated quality at the second base station is better than the estimated quality between the first base station and the first mobile station.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein the quality is the estimated bit error rate of the received signal.
Claim 5
Dependent Claim
23 words
A method according to claim 1 wherein the quality is a function of the distance between the mobile station and the base stations.
Claim 6
Dependent Claim
20 words
A method according to claim 4 wherein the distance is estimated from the time alignment used to synchronize time slots.
Claim 7
Dependent Claim
21 words
A method according to claim 1 wherein the quality is a function of the signal strength measured at the base stations.
Claim 8
Dependent Claim
21 words
A method according to claim 1 wherein the quality is a function of the signal strength measured at the mobile stations.
Claim 9
Independent Claim
121 words
A method of controlling communications in a cellular communications system comprising the steps of: estimating directly or indirectly parameter values indicative of quality of information transfer on communication channels used for ongoing calls in a cell; comparing estimated parameter values indicative of quality with parameter values set by information transfer quality requirements; changing the communication channel of at least one call from full rate to half rate when the comparison indicates that a half rate communication channel would provide sufficient quality for the call; and changing the communication channel of at least one call from half rate to full rate when the com- parision indicates that a full rate communication channel will be required to provide sufficient quality for the call.
Claim 10
Independent Claim
121 words
A method of controlling communications in a cellular communications system comprising the steps of: estimating directly or indirectly parameter values indicative of quality of information transfer on communication channels used for ongoing calls in a cell; comparing estimated parameter values indicative of quality with parameter values set by information transfer quality requirements; changing the communication channel of at least one call from full rate to half rate when the comparison indicates that a half rate communication channel would provide sufficient quality for the call; and changing the communication channel of at least one call from half rate to full rate when the com- parision indicates that a full rate communication channel will be required to provide sufficient quality for the call.
Claim 11
Dependent Claim
14 words
A method according to claim 8 wherein the quality is a function of distance.
Claim 12
Dependent Claim
20 words
A method according to claim 9 wherein the distance is estimated from the time alignment used to synchronize time slots.
Claim 13
Dependent Claim
22 words
A method according to claim 8 wherein the quality is a function of the estimated bit error rate of the information transfer.
Claim 14
Dependent Claim
17 words
A method according to claim 8 wherein the quality is a function of a measured signal strength.
Claim 15
Independent Claim
100 words
A method of communication and handoff in a cellular mobile radio having a plurality of base stations in the cells, comprising the steps of: transmitting a speech signal between a first base station and at least a first mobile station; estimating periodically the quality of the received speech signal; assigning the mobile station to a half rate channel of the first base station if the estimated quality of the speech signal is less than desired; and assigning the mobile station to a full rate channel of the first base station if the estimated quality of the speech signal is acceptable.
Claim 16
Independent Claim
100 words
A method of communication and handoff in a cellular mobile radio having a plurality of base stations in the cells, comprising the steps of: transmitting a speech signal between a first base station and at least a first mobile station; estimating periodically the quality of the received speech signal; assigning the mobile station to a half rate channel of the first base station if the estimated quality of the speech signal is less than desired; and assigning the mobile station to a full rate channel of the first base station if the estimated quality of the speech signal is acceptable.
Claim 17
Dependent Claim
68 words
A method according to claim 13 which further includes the steps of: estimating periodically the quality of the received speech signal at a second base station; and handing off the first mobile station from the first base station to the second base station if the estimated quality of the second base station is better than the estimated quality between the first base station and the first mobile station.
Claim 18
Dependent Claim
19 words
A method according to claim 14 wherein the quality is the estimated bit error rate of the received signal.
Claim 19
Dependent Claim
23 words
A method according to claim 14 wherein the quality is a function of the distance between the mobile station and the base stations.
Claim 20
Dependent Claim
20 words
A method according to claim 16 wherein the distance is estimated from the time alignment used to synchronize time slots.
Claim 21
Dependent Claim
21 words
A method according to claim 14 wherein the quality is a function of the signal strength measured at the base stations.
Claim 22
Dependent Claim
21 words
A method according to claim 14 wherein the quality is a function of the signal strength measured at the mobile stations.
References Cited (Backward Citations)
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