Method, communication system and apparatus for switching calls on a common channel to another channel

Claim 3

A method according to claim 1, wherein the call is held in said first call state for a predetermined time period (T init1 ) before being set into said second call state.

Claim 4

A method according to claim 1, wherein the call is successively set (M15) to a third, a fourth . . . and a n-th call state in which respectively third, fourth . . . and n-th different predetermined transmission conditions are used (M23) for determining a switching, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states.

Claim 5

A method according to claim 3, wherein the call is held in said second, third, fourth . . . and n-th call state respectively for a predetermined time period (T init1 , T init2 ) before transiting to a next call state.

Claim 6

A method according to claim 3, a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.

Claim 7

A method according to claim 3, wherein the transmission conditions are dependent on the number of calls already occupying the channel (CC1) and/or the number of repetitive attempts of other calls to use the same channel.

Claim 8

A method according to claim 1, wherein when the call is switched to another channel (CC2), the call enters said first call state on the another channel (CC2).

Claim 9

A method according to claim 1, wherein the transmission conditions comprise a field strength on the channel and/or a mean bit error rate (BER) on the channel and/or a measured distance between a transmitter station (BS) and said subscriber stations (A; B).

Claim 10

A method according to claim 8, wherein said bit error rate (BER, RXQUAL -- XX) is measured a predetermined first number of times (N 3 init ; N3) over a predetermined time period (T speech ) in each of said call states; a second number of times (P init ; P) is determined indicating how often said measured bit error rate values (BER, RXQUAL -- XX) exceed a predetermined maximum bit error rate (BER max , L -- RXQUAL); the predetermined transmission conditions respectively specify a maximum number of times (P3 init ; P3) that said measured bit error rate values (BEE, RXQUAL -- XX) are allowed to exceed said maximum bit error rate (BER, RXQUAL -- XX); and a switching of the call to said another channel (CC2) is performed when said second number (P init ; P) is larger than said maximum number (P3 init ; P3).

Claim 11

A method according to claim 9, wherein said maximum number of times (P3 init ; P3) for said first call state is lower than for said at least one second call state.

Claim 12

A method according to claim 1, wherein the transmission conditions are dependent on the number of calls already occupying the channel (CC1) and/or the number of repetitive attempts of other calls to use the same channel.

Claim 13

A method according to claim 1, wherein the call is successively set (M15) to a third, a fourth . . . and a n-th call state in which respectively third, fourth . . . and n-th different predetermined transmission conditions are used (M23) for determining a switching, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states; and n successive call states are provided, wherein a call priority indication is respectively used for each call and/or each subscriber station whici indicates that said call after being set up on said channel (CC1) is set into the 1st call state of said n call states and is set into the 2nd call state when the call is not switched in said 1st call state.

Claim 14

A method according to claim 1, wherein the call is successively set (M15) to a third, a fourth . . . and a n-th call state in which respectively third, fourth . . . and n-th different predetermined transmission conditions are used (M23) for determining a switching, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states; and n successive call states are provided, wherein a call priority indication is respectively used for each call and/or each subscriber station which indicates that the call after being set up on the channel (CC1) is set into a predetermined call state of said n call states.

Claim 15

A method according to claim 13, wherein said call priority indication further indicates the numbers of the call states into which the call set into said predetermined call state is to be successively set, if predetermined transmission conditions are fulfilled in respective call states.

Claim 16

A method according to claim 14, wherein said call priority indication further indicates that a call after having been set to at least two different call states, will be kept in a call state, even if said predetermined transmission conditions are not fulfilled.

Claim 17

A method according to claim 1, wherein the call is held in said first call state for a predetermined time period (T init1 ) before being set into said second call state; said call priority indication further indicates that a call after having been set to at least two different call states, will be kept in a call state, even if said predetermined transmission conditions are not fulfilled; and said predetermined holding time and the predetermined transmission conditions in each call state are dependent on said call priority indication.

Claim 18

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; and f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively.

Claim 19

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; and f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively.

Claim 20

A system according to claim 17, wherein said call state setting means (SSM) holds the call in said first call state for a predetermined time period (T init1 ) before setting the call into said second call state.

Claim 21

A system according to claim 17, wherein said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states.

Claim 22

A system according to claim 19, wherein said call state setting means (SSM) holds the call in said second, third, fourth . . . and n-th call state respectively for a predetermined time period (T init1 , T init2 ) before setting the call to a next call state.

Claim 23

A system according to claim 19, wherein a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.

Claim 24

A system according to claim 19, wherein said transmission conditions are dependent on the number of other calls already occupying said channel (CC1) and/or the number of repetitive attempts of other calls to use the same channel.

Claim 25

A system according to claim 1, wherein when said switching means (SM) switches the call to the another channel (CC2) said call stage setting means (SSM) sets the call into said first call state on the another channel (CC2).

Claim 26

A system according to claim 17, wherein said transmission condition determining means (TCDM) includes a field strength measurement means (6) for measuring a field strength on the channel and/or an error detection means (7) for detecting a mean bit error rate (BER) on the channel (CC1) and/or a distance measuring means (8) for measuring a distance between a transmitter station (BS) and the subscriber stations (A; B).

Claim 27

A system according to claim 24, wherein said error detection means (7) measures said bit error rate (BER, RXQUAL -- XX) a predetermined first number of times (N3 init ; N3) over a predetermined time period (T speech ) in each of said call states; said error detection means (7) determines a second number of times (P init ; P) indicating how often said measured bit error rate values (BER, RXQUAL -- XX) exceed a predetermined maximum bit error rate (BER max , L -- RXQUAL); said predetermined transmission conditions respectively specify a maximum number of times (P3 init ; P3) that said measured bit error rate values (BER, RXQUAL -- XX) are allowed to exceed said maximum bit error rate (BER, RXQUAL -- XX); and said switching means (SM) switches the call to said another channel (CC2) when said second number (P init ; P) is larger than said maximum number (P3 init ; P3).

Claim 28

A system according to claim 25, wherein said maximum number of times for said first call state is lower than for said at least one second call state.

Claim 29

A system according to claim 17, wherein said transmission conditions are dependent on the number of other calls already occupying said channel (CC1) and/or the number of repetitive attempts of other calls to use the same channel.

Claim 30

A system according to claim 17, wherein the communication network (GSM, CTS) is a GSM network or a GSM-based cordless telephone system.

Claim 31

A system according to claim 28, wherein said switching means is a base station (BS) and/or a mobile station (MS) of said GSM-network.

Claim 32

A system according to claim 17, wherein said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states; and n successive call states are provided, wherein a call priority indication is respectively used for each call and/or each subscriber station which indicates that said call after being set up on said channel (CC1) is set into the 1st call state of said n call states and is set into the 2nd call state when the call is not switched in said 1st call state.

Claim 33

A system according to claim 17, wherein said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states; and n successive call states are provided, wherein a call priority indication is respectively used for each call and/or each subscriber station which indicates that said call after being set up on said channel (CC1) is set into a predetermined call state of said n call states.

Claim 34

A system according to claim 31, wherein said call priority indication further indicates the numbers of the call states into which the call set into said predetermined call state is to be successively set, if predetermined transmission conditions are fulfilled in respective call states.

Claim 35

A system according to claim 32, wherein said call priority indication further indicates that a call after having been set to at least two different call states, will be kept in a call state, even if said predetermined transmission conditions are not fulfilled.

Claim 36

A system according to claim 17, wherein said call state setting means (SSM) holds the call in said first call state for a predetermined time period (T init1 ) before setting the call into said second call state; said call priority indication further indicates that a call after having been set to at least two different call states, will be kept in a call state, even if said predetermined transmission conditions are not fulfilled; and said predetermined holding time and the predetermined transmission conditions in each call states are dependent on said call priority indication.

Claim 37

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the all into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; and f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively.

Claim 38

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the all into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; and f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively.

Claim 39

An apparatus (SA) according to claim 35, characterized in that said call state setting means (SSM) holds said call attempting to use a channel (CC2) already occupied at least one other call in said first call state for a predetermined time period (T init1 ) before setting said call into said second call state.

Claim 40

An apparatus (SA) according to claim 35, wherein said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective call states.

Claim 41

An apparatus (SA) according to claim 37, wherein a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.

Claim 42

An apparatus (SA) according to claim 35, wherein when said switching means (SM) switches the call to the another channel (CC2) said call state setting means sets the call in said first call state on the another channel (CC2).

Claim 43

An apparatus (SA) according to claim 35, wherein said transmission condition determining means (TCDM) includes a field strength measurement means (6) for measuring a field strength on the channel and/or an error detection means (7) for detecting a mean bit error rate (BER) on the channel and/or a distance measuring means (9) for measuring a distance be ween a transmitter station and the subscriber stations (A; B).

Claim 44

A base station (BS) of a GSM-network including a switching apparatus (SA) according to claim 35.

Claim 45

A mobile station (MS) of a GSM-network including a switching apparatus (SA) according to claim 35.

Claim 46

An apparatus according to claim 35, wherein said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective call states; and n successive call states are provided, wherein a call priority indication is respectively used for each call and/or each subscriber station which indicates that said call after being set up on said channel (CC1) is set into the 1st call state of said n call states and is set into the 2nd call state when the call is not switched in said 1st call state.

Claim 47

An apparatus according to claim 35, wherein said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective call states; and n successive call states are provided, wherein a call priority indication is respectively used for each call and/or each subscriber station which indicates that said call after being set up on said channel (CC1) is set into a predetermined call state of said n call states.

Claim 48

An apparatus according to claim 44, wherein said call priority indication further indicates the numbers of the call states into which the call set into said predetermined call state is to be successively set, if predetermined transmission conditions are fulfilled in respective call states.

Claim 49

An apparatus according to claim 45, wherein said call priority indication further indicates that a call after having been set to at least two different call states, will be kept in a call state, even if said predetermined transmission conditions are not fulfilled.

Claim 50

An apparatus according to claim 35, wherein said call state setting means (SSM) holds said call attempting to use a channel (CC2) already occupied at least one other call in said first call state for a predetermined time period (T init1 ) before setting said call into said second call state; said call priority indication further indicates that a call after having been set to at least two different call states, will be kept in a call state, even if said predetermined transmission conditions are not fulfilled; and said predetermined holding time and the predetermined transmission conditions in each call states are dependent on said call priority indication.

Claim 59

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; and g) said call state setting means (SSM) holding the call in said first call state for a predetermined time period (T init1 ) before setting the call into said second call state.

Claim 60

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; and g) said call state setting means (SSM) holding the call in said first call state for a predetermined time period (T init1 ) before setting the call into said second call state.

Claim 61

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; and g) said transmission condition setting means (TCSM) setting third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively setting the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states.

Claim 62

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; and g) said transmission condition setting means (TCSM) setting third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively setting the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied in said respective call states.

Claim 63

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) an error detection means (7) measures said bit error rate (BER, RXQUAL -- XX) a predetermined first number of times (N3 init ; N3) over a predetermined time period (T speech ) in each of said call states; an error detection means (7) determines a second number of times (P init ; P) indicating how often said measured bit error rate values (BER, RXQUAL -- XX) exceed a predetermined maximum bit error rate (BER max , L -- RXQUAL); said predetermined transmission conditions respectively specify a maximum number of times (P3 init ; P3) that said measured bit error rate values (BER, RXQUAL -- XX) are allowed to exceed said maximum bit error rate (BER, RXQUAL -- XX); and said switching means (SM) switchrd the call to said another channel (CC2) when said second number (P init ; P) is larger than said maximum number (P3 init ; P3).

Claim 64

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) an error detection means (7) measures said bit error rate (BER, RXQUAL -- XX) a predetermined first number of times (N3 init ; N3) over a predetermined time period (T speech ) in each of said call states; an error detection means (7) determines a second number of times (P init ; P) indicating how often said measured bit error rate values (BER, RXQUAL -- XX) exceed a predetermined maximum bit error rate (BER max , L -- RXQUAL); said predetermined transmission conditions respectively specify a maximum number of times (P3 init ; P3) that said measured bit error rate values (BER, RXQUAL -- XX) are allowed to exceed said maximum bit error rate (BER, RXQUAL -- XX); and said switching means (SM) switchrd the call to said another channel (CC2) when said second number (P init ; P) is larger than said maximum number (P3 init ; P3).

Claim 65

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied irn said respective call states; and h) a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.

Claim 66

A communication system of a channel re-use type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and where calls are switched to another channel (CC2) when a substantial interference between them exist, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; and c) a switching means (SM) for switching the calls to another channel (CC2) when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched to another channel (CC2) in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel in said first or second call state when the determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) said transmission condition setting means (TCSM) sets third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means (SSM) successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th predetermined transmission conditions are not satisfied irn said respective call states; and h) a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.

Claim 67

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition settinig means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) said call state setting means (SSM) holds said call attempting to use a channel (CC2) already occupied at least one other call in said first call state for a predetermined time period (T init1 ) before setting said call into said second call state.

Claim 68

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition settinig means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) said call state setting means (SSM) holds said call attempting to use a channel (CC2) already occupied at least one other call in said first call state for a predetermined time period (T init1 ) before setting said call into said second call state.

Claim 69

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) said transmission condition setting means (TCSM) setting third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective cell states.

Claim 70

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; wherein g) said transmission condition setting means (TCSM) setting third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective cell states.

Claim 71

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; and f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; g) said transmission condition setting means (TCSM) setting third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective call states; wherein h) a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.

Claim 72

A switching apparatus (SA) in a communication system of a channel-reuse type where at least two calls (A, B, C) between at least two subscriber stations (MS1-MS4) can simultaneously use the same channel (CC1) when substantially no interference between them exists and said calls are switched to another channel (CC2) when a substantial interference between them exists, comprising: a) a transmission condition determining means (TCDM) for determining transmission conditions of the calls on the channel (CC1); b) a transmission condition setting means (TCSM) for setting predetermined transmission conditions for the calls; c) a switching means (SM) for switching the calls when said determined transmission conditions do not satisfy predetermined transmission conditions; d) a call state setting means (SSM) for setting a call after being set-up on a channel (CC1) into a first call state and for setting the call into at least a second call state, when the call is not switched in said first call state; e) said transmission condition setting means (TCSM) setting respectively different predetermined transmission conditions for said first and said at least one second call state; and f) said switching means (SM) switching the call to another channel (CC2) in said first or second call state when said determined transmission conditions of the call in said first or second call state do not satisfy said first or second predetermined transmission conditions, respectively; g) said transmission condition setting means (TCSM) setting third, fourth . . . and n-th different predetermined transmission conditions for a third, fourth . . . and n-th call state and said call state setting means successively sets the call to said third, fourth . . . and n-th call state in which said switching means respectively uses said third, fourth . . . and n-th different predetermined transmission conditions, when said second, third . . . (n-1)-th transmission conditions are not satisfied in said respective call states; wherein h) a n-th predetermined transmission condition specifies a lower transmission quality of the call than a transmission quality specified by a (n-1)-th predetermined transmission condition.