Method of controlling transmission on a same radio channel of variable-rate information streams in radio communication systems, and radio communication system using this method

Claim 2

Method according to Claim 1, characterized in that each stream is allocated the emission rate and the redundancy which meet the respective needs if the total rate (r tot ) resulting from the combination of the streams on the channel, expressed as the sum of the stream emission rates and the rate increments due to the redundancies, does not exceed a rate (r₅) imposed by the system conditions, and otherwise each stream is allocated such an emission rate and such a redundancy as to minimize a cost of the communication, linked to the quality of the particular communication and of the service offered by the system, and given by the sum of the costs resulting from the individual needs.

Claim 3

Method according to Claim 1 or 2, characterized in that the radio channel is the communication channel between a mobile station and a base station of a mobile communication system, and the assessment of said needs is performed separately in the mobile station and in a fixed part of the system, respectively for the direction from the mobile station towards the fixed part and for the opposite direction.

Claim 4

Method according to any of Claims 1 to 3, characterized in that, for each direction of the communication, the information on said needs are represented by indices (I1...I5), linked to one of the possible source rates of each stream, to one of the possible redundancy schemes and to one of the possible channel rates.

Claim 5

Method according to Claim 4, characterized in that said indices constitute reading addresses for accessing stored information on the emission and channel transmission rates and on the rate increments caused by the redundancies, as well as on the costs associated with the rates and redundancies actually allocable.

Claim 6

Method according to Claim 5, characterized in that the information on the channel needs is represented by a single index for all information streams.

Claim 7

Method according to any of Claims 4 to 6, characterized in that the stored information relative to the source rates and to the channel rates consists of vectors with as many components as there are possible rate values, and the information on the rate increments caused by the redundancies is represented by matrices in which each component is associated with a combination of source/redundancy rates.

Claim 8

Method according to any of Claims 4 to 7, characterized in that the stored information relative to costs is in the form of digital values, normalized with respect to a common base and organized into matrices in which each component is associated with a combination of rates/ redundancies required and rates/redundancies allocable.

Claim 9

Method according to Claim 8, characterized in that said cost matrices are constant matrices.

Claim 10

Method according to any of Claims 4 to 7, characterized in that the information stored relative to costs related to the source and channel needs is in the form of digital values organized into vectors, updated at every time interval.

Claim 11

Method according to any preceding claim, characterized in that the information streams are digitally coded speech signals and control signals of a speech communication .

Claim 12

Method according to any of Claims 1 to 10, characterized in that the information streams are data and control signals of a variable-rate data transmission.

Claim 13

Method according to any preceding claim, characterized in that the mobile communication system is a system in which channel access occurs according to code division techniques and the transmission period on the channel is divided into frames, and in that the determination of the rate and of the redundancy to be allocated to the individual streams is made at each frame.

Claim 14

Method according to any of claims 1 to 12, characterized in that the communication system is a system in which channel access for variable-rate transmissions occurs according to time division technique.

Claim 15

Communication system including at least two stations (M1...Mh; RNC; B1...Bn) connected via radio channels and including: - sources (CV1, CS1; CV2, CS2) of variable-rate information streams relative to a single communication that must be combined on a single radio channel (6), each source being able to operate, in a given time interval, with a rate (r₁, r₂) chosen within a respective set of rates; - means (CC1, CC2; CC3, CC4) to introduce into each stream, in said time interval, a redundancy chosen from a set of possible redundancy schemes, each of which causes an increment (r₃, r₄) in the rate of the stream emitted by the source; - means (MX1, MX2) to combine the individual streams into a single stream to be transmitted on the channel (6); - management units (MM, BM, RNCM) of the stations; characterized in that said stations are associated with a variable-rate stream control unit (UC1, UC2) which, for each communication: receives from the sources (CV1, CS1; CV2, CS2 ) information on the source needs in terms of the emission rate which is best suited to the characteristics of the respective information stream in that interval; receives from the management units (MM, RNCM) information on the needs of the channel (6) and of the entire system in that interval, expressed in terms of redundancy and respectively of transmission rate on the channel; determines a particular source rate and a particular redundancy for each stream and provides the sources (CV1, CS1; CV2, CS2) and the means (CC1, CC2; CC3, CC4) for redundancy introduction with commands for the choice of that particular source rate and redundancy, the rates and redundancies chosen being those which guarantee the attainment of a predetermined quality of the particular communication and of the service offered by the system.

Claim 16

Communication system according to Claim 15, characterized in that the rates and redundancies chosen are those which satisfy the source and channel needs in that interval, if the total rate (r tot ) of the stream resulting from the combination, expressed as the sum of the emission rates of the streams and the rate increments caused by the redundancies, does not exceed a rate (r₅) determined by the system conditions, while otherwise the rates and redundancies are chosen so as to minimize a total cost of the communication, linked to the quality of the particular communication and of the service offered by the system, and given by the sum of the costs resulting from the individual needs.

Claim 17

Communication system according to Claim 15 or 16, characterized in that each control unit (UC1; UC2) includes: - a first group of memories (ME1-1...ME1-5), which store information relative to the possible rates of the streams emitted by the sources, to the combinations of each of these rates with each of the redundancies foreseen for the respective stream, and to the possible rates on the channel, and which are addressed respectively by the information on the needs of the sources (CV1, CS1; CV2, CS2), of the channel (6) and of the system supplied by the sources (CV1, CS1; CV1, CS2) and the management units (MM, RNCM), respectively; - a second group of memories (ME2-1...ME2-5), which store information on the costs associated with the possible choices of rates of the streams flowing from the sources, of the redundancy required by the channel conditions and of the rate on the channel (6), and are addressed in reading at least by the information provided by the sources (CV1, CS1; CV2, CS2) and by the management units (MM, RNCM); - a processing unit (EL), which receives from the sources (CV1, CS1; CV2, CS2) and from the management units (MM, RNCM) information on the source, channel and system needs, and from the first and second group of memories (ME1-1...ME1-5, ME2-1...ME2-5) information on the rates, redundancies and costs, and provides the sources (CV1, CS1; CV2, CS2) and the means (CC1...CC4) of redundancy introduction with commands for the choice of the emission rate and of the redundancy.

Claim 18

Communication system according to any of Claims 15 to 17, characterized in that the sources (CV1, CS1; CV2, CS2) and the management units (MM, RNCM) provide the information on the source, channel and system needs in the form of indices (I1...I5) which constitute reading addresses or parts of the reading addresses in said memories (ME1-1...ME2-5).

Claim 19

Communication system according to Claim 17 or 18, characterized in that, in the first group of memories (ME1-1...ME1-5), the memories (ME1-1, ME1-2, ME1-5) for the information on the source and channel needs store rate values organized into vectors, each having as many components as there are possible values for the source and channel rates, and the memories (ME1-3, ME1-4) for information on the channel needs store rate values organized into matrices in which each row is associated with one of the rate values of the respective source, and each column with one of the possible increments caused by the redundancy.

Claim 20

Communication system according to any of Claims 17 to 19, characterized in that the memories of the second group (ME2-1...ME2-5) store numerical cost values organized into matrices, and each memory location is addressed jointly by one of the said indices (I1...I5) and by a further index, generated by said processing unit (EL) during the determination of the rates and of the redundancies and associated with a rate or a redundancy that can be actually allocated to the individual streams emitted by the source or respectively to the total rate of the stream resulting from the combination.

Claim 21

Communication system according to Claim 20 characterized in that said cost matrices are constant matrices.

Claim 22

Communication system according to any of Claims 17 to 19 characterized in that the memories of the second group (ME2-1...ME2-4) storing costs related to the source and channel needs store numerical values organized into vectors, updated at each time interval.

Claim 23

Communication system according to any of Claims 15 to 22, characterized in that the information streams are speech signals coded in digital form and control signals of a speech communication.

Claim 24

Communication system according to any of Claims 15 to 22, characterized in that the information streams are data and control signals of a variable-rate data transmission.

Claim 25

Communication system according to any of Claims 15 to 24, characterized in that the communication system is a mobile communication system comprising a plurality of mobile stations (M1...Mh) and a fixed part (RNC; B1...Bn), consisting of base stations (B1...Bn) and of radio network control units (RNC), and the unit (UC1, UC2) controlling the variable rate streams is provided in each mobile station (M1...Mh) and in the fixed part (RNC; B1...Bn).

Claim 26

Communication system according to Claim 25, characterized in that the mobile communication system is a system in which channel access occurs through code division techniques.

Claim 27

Communication system according to Claim 25, characterized in that the mobile communication system is a system in which channel access for a variable-rate transmission occurs through time division techniques.