Method of allocating resources in a radiocommunication system and base station for implementing the said method
View Patent ↗For a new transmission time interval, respective weights are assigned to queues. The queues are ranked as a function of the weights assigned to them. The first queue according to the ranking is selected. A quantity dependent on the radio conditions in respect of the radio terminal to which the said radio session relates, and on a number of packets already transmitted within the context of the said session is calculated for each session within the context of which it is required to transmit data packets placed in the selected queue. Communication resources are allocated to some of the sessions so as to transmit a number of data packets placed in the selected queue, depending on the weight assigned to the selected queue, the said sessions being determined as a function at least of the said quantities calculated. Once the selected queue has been served, and if there are still resources available for the transmission time interval, we pass to the next queue in the ranking so as to serve it.
1. Method of allocating resources in a radiocommunication system comprising at least one base station devised to transmit, in successive transmission time intervals, data packets destined for radio terminals, on communication resources shared between the radio terminals, within the context of transmission sessions, each transmission session relating to a radio terminal among the said radio terminals, in which there is provided a set of queues that are devised so that the data packets to be transmitted within the context of each transmission session are placed dynamically in one of the queues, the method comprising:
(a) assigning a respective weight to each queue;
(b) ranking the queues as a function of at least the weights respectively assigned to them;
(c) selecting a queue as a function of its position in the ranking of step (b);
(d) for a new transmission time interval, calculating for each transmission session within the context of which it is required to transmit data packets placed in the selected queue a quantity dependent at least on the radio conditions with respect to the radio terminal to which said transmission session relates, and on a number of packets already transmitted within the context of said transmission session;
(e) allocating communication resources to at least some of the transmission sessions within the context of which said transmission sessions are required to transmit data packets placed in the selected queue, so as to transmit a number of data packets placed in the selected queue, said number of data packets depending on the weight assigned to the selected queue, said transmission sessions to which communication resources are allocated being determined as a function of at least the quantities calculated in step (d); and
(f) repeating steps (d) to (f), as long as the queues have not all been selected and as long as there are still resources available for said transmission time interval, the queue following the queue previously selected in the ranking established in step (b) is selected.
2. Method according to claim 1 , in which step (b) comprises a ranking of the queues according to a descending order of the weights respectively assigned to the queues.
3. Method according to claim 1 , wherein step (b) comprises a ranking of the queues according to an ascending order of the ratio, calculated for some at least of the queues, of a number of data packets already transmitted from the queue over the weight respectively assigned to the queue.
4. Method according to claim 1 , in which step (c) comprises the selection of the first queue in the ranking of the queues performed in step (b) and in which the repetition of step (c), provided for in step (f), comprises the selection of the queue having an immediately higher position than the previously selected queue, according to the ranking of the queues performed in step (b).
5. Method according to claim 1 , wherein in step (e), the number of resources allocated to each session within the context of which said transmission session-is required to transmit data packets placed in the selected queue depends on the radio conditions with respect to the radio terminal to which the said radio session relates.
6. Method according to claim 1 , wherein, among the set of queues, said one of the queues in which the data packets to be transmitted within the context of each transmission session are placed according to a priority level allocated to the a respective transmission session.
7. Method according to claim 1 , wherein the weights respectively assigned to the queues vary between bounds whose respective values fluctuate according to a number of data packets already transmitted, from the corresponding queue.
8. Method according to claim 1 , wherein the quantity dependent at least on the radio conditions with respect to the radio terminal to which said transmission session relates and on a number of packets already transmitted within the context of said transmission session, takes account of the quantity calculated for the transmission time interval preceding the new transmission time interval.
9. Method according to claim 1 , wherein the quantity dependent at least on the radio conditions with respect to the radio terminal to which said transmission session relates and on a number of packets already transmitted within the context of said transmission session decreases as a function of the quality of the radio link between the base station and said radio terminal, and increases as a function of the number of packets already transmitted within the context of the said transmission session, and in which said transmission sessions to which communication resources are allocated are determined according to an ascending order of said quantity.
10. Method according to claim 1 , wherein said transmission sessions to which communication resources are allocated are determined moreover on the basis of a reception capability of the radio terminals to which the said transmission sessions relate, such as a minimum time between two receptions of data packets transmitted over respective transmission time intervals, a number of codes that are applied to data that can be decoded over a transmission time interval, or a type of modulation that is applied to data to be demodulated.
11. Method according to claim 1 , wherein said sessions to which communication resources are allocated depend furthermore on whether data packets to be transmitted to radio terminals to which said transmission sessions relate have already been transmitted previously.
12. Method according to claim 1 , wherein steps (a) to (f) are executed for each new transmission time interval.
13. Method according to claim 1 , wherein the sum of the weights assigned to the queues in step (a) is constant.
14. Base station in a radiocommunication system, comprising means for transmitting, in successive transmission time intervals, data packets destined for radio terminals, on communication resources shared between the radio terminals, within the context of transmission sessions, each transmission session relating to a radio terminal among said radio terminals, in which there is provided a set of queues that are devised so that the data packets to be transmitted within the context of each transmission session are placed dynamically in one of the queues, the base station further comprising:
(a) assigning means for assigning a respective weight to each queue;
(b) ranking means for ranking the queues as a function at least of the weights respectively assigned to them;
(c) first selecting means for selecting a queue as a function of its position in the ranking;
(d) calculating means for calculating a quantity dependent at least on the radio conditions in respect of the radio terminal to which the said transmission session relates, and on a number of packets already transmitted within the context of the said transmission session, for a new transmission time interval, for each session within the context of which said transmission session is required to transmit data packets placed in the selected queue;
(e) allocating means for allocating communication resources to at least some of the sessions within the context of which said transmission sessions are required to transmit data packets placed in the selected queue, so as to transmit a number of data packets placed in the selected queue, said number of data packets depending on the weight assigned to the selected queue, said transmission sessions to which communication resources are allocated being determined as a function of at least the quantities calculated by the means (d); and
(f) second selecting means for, as long as the queues have not all been selected and as long as there are still resources available for the said transmission time interval, selecting the queue following the queue previously selected in the ranking.
15. Base station according to claim 14 , wherein the ranking means is arranged for ranking the queues according to a descending order of the weights respectively assigned to the queues.
16. Base station according to claim 14 , wherein the ranking means is arranged for ranking the queues according to an ascending order of the ratio, calculated for some at least of the queues, of a number of data packets already transmitted from the queue over the weight respectively assigned to the queue.
17. Base station according to claim 14 , wherein the selecting means is arranged for selecting the first queue in the ranking of the queues performed by the ranking means, and in which the second selecting means is arranged for selecting the queue having an immediately higher position than the previously selected queue, according to the ranking of the queues performed by the ranking means.
18. Base station according to claim 14 , wherein the number of resources allocated by the allocating means to each transmission session within the context of which said transmission session is required to transmit data packets placed in the selected queue depends on the radio conditions in respect of the radio terminal to which the said radio session relates.
19. Base station according to claim 14 , wherein said queues in which the data packets to be transmitted within the context of a transmission session are placed among the set of Queues, depends on a priority level allocated to the session.
20. Base station according to claim 14 , wherein the assigning means assigns weights which vary between bounds whose respective values fluctuate according to a number of data packets already transmitted, from the corresponding queue.
21. Base station according to claim 14 , wherein the quantity dependent at least on the radio conditions in with respect to the radio terminal to which said transmission session relates and on a number of packets already transmitted within the context of said transmission session, taking account of the quality calculated for the transmission time interval preceding the new transmission time interval.
22. Base station according to claim 14 , wherein the quantity dependent at least on the radio conditions with respect to the radio terminal to which said transmission session relates and on a number of packets already transmitted within the context of said session decreases as a function of the quality of the radio link between the base station and said radio terminal, and increases as a function of the number of packets already transmitted within the context of said transmission session, and wherein said transmission sessions to which communication resources are allocated are determined according to an ascending order of the said quantity.
23. Base station according to claim 14 , wherein the allocating means allocates communication resources to sessions determined moreover on the basis of a reception capability of the radio terminals to which the said transmission sessions relate, said capacity comprising: a minimum time between two receptions of data packets transmitted over respective transmission time intervals, a number of codes that are applied to the data that can be decoded over a transmission time interval, or a type of modulation that is applied to the data that can be demodulated.
24. Base station according to claim 14 , wherein the allocating means allocates communication resources to transmission sessions depending furthermore on the fact that data packets to be transmitted to radio terminals to which said transmission sessions relate have already been transmitted previously.
25. Base station according to claim 14 , wherein the sum of the weights assigned to the queues by the assigning means is constant.