Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
347 words
A method of managing transmission errors between a base station (17) and a transcoder (16), in a digital radiocommunications system for mobile stations, said system comprising a plurality of base stations, each of which controls a plurality of mobile stations via radio links; a signal from a mobile station (11) to a remote terminal (12) (up direction) being conveyed: from said mobile station (11) to a base station (17) via a radio link; from said base station (17) to a transcoder (16) in the form of data frames containing check data and useful data, said useful data being encoded by using encoding that is recognized by said base station (17) and by said transcoder (16); and from said transcoder (16) to a switching center (14) establishing connection to said remote terminal (12); and a signal from said remote terminal (12) to said mobile station (11) (down direction) being conveyed symmetrically; said method being characterized in that said transcoder (16) performs the following operations: receiving and decoding (22, 24, 28, 214, 220, 225, 227) the frames transmitted by said base station (17); detecting (28, 220, 227) transmission errors in the up direction by analyzing the received and decoded frames; in the presence of a transmission error in the up direction, systematically inserting (29, 221, 228) an error message in a frame addressed to said base station (17) without interrupting useful data transmission to said base station (17); and interrupting (27, 219, 231, 233) data transmission to said base station (17) on detection (26, 217, 230, 232) of an up-direction transmission interruption request (314) generated by said base station (17); and in that said base station (17) performs the following operations: receiving and decoding (32, 36) frames transmitted by said transcoder; detecting (36) transmission errors (38) in the down direction by analyzing the received and decoded frames; and interrupting data transmission to said transcoder (down direction) and generating (310) an up-direction transmission interruption request (314) when the transmission errors detected in the down direction (312) and/or reported by an error message in the up direction (311) satisfy predetermined conditions.
Claim 2
Independent Claim
347 words
A method of managing transmission errors between a base station (17) and a transcoder (16), in a digital radiocommunications system for mobile stations, said system comprising a plurality of base stations, each of which controls a plurality of mobile stations via radio links; a signal from a mobile station (11) to a remote terminal (12) (up direction) being conveyed: from said mobile station (11) to a base station (17) via a radio link; from said base station (17) to a transcoder (16) in the form of data frames containing check data and useful data, said useful data being encoded by using encoding that is recognized by said base station (17) and by said transcoder (16); and from said transcoder (16) to a switching center (14) establishing connection to said remote terminal (12); and a signal from said remote terminal (12) to said mobile station (11) (down direction) being conveyed symmetrically; said method being characterized in that said transcoder (16) performs the following operations: receiving and decoding (22, 24, 28, 214, 220, 225, 227) the frames transmitted by said base station (17); detecting (28, 220, 227) transmission errors in the up direction by analyzing the received and decoded frames; in the presence of a transmission error in the up direction, systematically inserting (29, 221, 228) an error message in a frame addressed to said base station (17) without interrupting useful data transmission to said base station (17); and interrupting (27, 219, 231, 233) data transmission to said base station (17) on detection (26, 217, 230, 232) of an up-direction transmission interruption request (314) generated by said base station (17); and in that said base station (17) performs the following operations: receiving and decoding (32, 36) frames transmitted by said transcoder; detecting (36) transmission errors (38) in the down direction by analyzing the received and decoded frames; and interrupting data transmission to said transcoder (down direction) and generating (310) an up-direction transmission interruption request (314) when the transmission errors detected in the down direction (312) and/or reported by an error message in the up direction (311) satisfy predetermined conditions.
Claim 3
Dependent Claim
31 words
A method according to claim 1, characterized in that said operation of detecting errors (28, 220, 227, 36) includes a step of detecting synchronization loss in said received and decoded data.
Claim 4
Dependent Claim
34 words
A method according to claim 1, characterized in that said operation of inserting (29, 221,228) an error message consists in changing the value of at least one check bit of one of said frames.
Claim 5
Dependent Claim
23 words
A method according to claim 3, characterized in that said bit is any one of bits C12 to C15 in the GSM frame.
Claim 6
Dependent Claim
91 words
A method according claim 1 characterized in that said base station (17) uses two counters (34, 39), a first counter (34) counting the number (311) of errors in the up direction during a first predetermined lapse of time (313), and a second counter (39) counting the number (312) of errors in the down direction during a second predetermined lapse of time (313); and in that said base station (17) decides to interrupt (314) a call when the value of at least one of said counters (34, 39) exceeds a predetermined threshold.
Claim 7
Dependent Claim
27 words
A method according to claim 5, characterized in that said first predetermined lapse of time (313) and/or said second predetermined lapse of time (313) have parameterizable durations.
Claim 8
Dependent Claim
36 words
A method according to claim 6, characterized in that said parameterizable duration is different for each base station (17), regardless of whether or not the base stations are controlled by the same base station controller (BSC).
Claim 9
Dependent Claim
73 words
A method according to claim 1, characterized in that said transcoder (16) performs the following operations: counting (210) the number of errors that appear during a third predetermined lapse of time; activating (211) an emergency clock when said number of errors is greater than a predetermined threshold; and interrupting (233) the call if said emergency clock reaches (223) a predetermined time-delay value, and if said transcoder (16) receives (232) a call interruption message.
Claim 10
Dependent Claim
48 words
A transcoder performing the method according to claim 1, said transcoder being characterized in that it includes detection means for detecting a transmission error in a signal transmitted by a base station, and transmission means for transmitting a message to said base station without interrupting useful data transmission.
Claim 11
Dependent Claim
45 words
A base station implementing the method according to claim 1, characterized in that it includes counting means (34, 39) for counting firstly the errors detected in the data transmitted by said transcoder, and secondly the errors reported by an error message transmitted by said transcoder.