We Claim:
[Claim 1]
A method in a system comprising a resource scheduler and a set of devices, each device hosting at least one application, each application transmitting a stream of messages to at least one receiver, characterized in that the method comprises :
- obtaining, for each stream, parameters comprising one message lifetime, one message period and a last buffering time of a message of said stream before a given time window starts ;
- deducing, from the obtained parameters, a set of configurations of said streams in said time window, a configuration of said streams being defined as a specific configuration of active streams, a stream being active in a given time slot in the case where there is a packet corresponding to said message to be sent or received ;
- computing, for each configuration, one configuration-based resource usage ratio per each stream such that the sum of the configuration-based resource usage ratios for said configuration is equal to one, said computing being under the constraint that, for each stream, there is at least one configuration for which the configuration-based resource usage ratio for said stream is not null ;
- transmitting data to the resource scheduler, said data comprising each configuration with its computed set of configuration-based resource usage ratios.
[Claim 2]
The method of claim 1, wherein the obtained parameters further comprise a resilience value being a maximum amount of time an application authorizes for not receiving any packet and wherein the size of said time window is defined from said resilience values. [Claim 3]
The method according to claim 1 or 2, wherein the method further comprises :
- averaging, for each stream, the configuration-based resource usage ratios of said stream ;
and wherein transmitting data to the resource scheduler comprises transmitting, for each stream, the averaged configuration-based resource usage ratio instead of transmitting each configuration with its computed set of configuration-based resource usage ratios.
[Claim 4]
The method according to any one of claims 1 to 3, wherein computing, for each
configuration, one configuration-based resource usage ratio per each stream comprises :
- selecting a cost function ;
- selecting a solving method ; and
- optimizing the cost function using the selected solving method to compute, for each configuration, one configuration-based resource usage ratio per each stream such that the sum of the configuration-based resource usage ratios for said configuration is equal to one, said computing being under the constraint that, for each stream, there is at least one configuration for which the configuration-based resource usage ratio for said stream is not null.
[Claim 5]
The method according to claim 4, wherein said cost function is selected in a set comprising the following cost functions:
(M/) (W)
ft 1 ; and
W (W) (W)
Jk - a PkJ J
where W is said time window ;
j is an index identifying a configuration Cj and k an index identifying a stream ;
is a configuration-based resource usage ratio of a stream of index k in a configuration of index j ;
^(W) is the set of configurations in said time window W in which the stream Sk is active ; Pek is a channel error probability ; and
n(w) is the number of time slots of said time window W in which said configuration Cj occurs.
[Claim 6]
The method according to claim 5, wherein, the selected cost function being /(.iy) — _(w)n(w)
nc ,6c/w) PekJ ' , optimizing the cost function using the selected solving method comprises minimizing J(V) for any stream Sk .
[Claim 7]
The method according to claim 5, wherein, the selected cost function being /(w) —
- compute, for each configuration, one configuration-based resource usage ratio per each stream such that the sum of the configuration-based resource usage ratios for said configuration is equal to one, said computing being under the constraint that, for each stream, there is at least one configuration for which the configuration-based resource usage ratio for said stream is not null ;
- transmit data to the resource scheduler, said data comprising each configuration with its computed set of configuration-based resource usage ratios.
[Claim 12]
A system comprising a processing device according to claim 11 and a resource scheduler, wherein the resource scheduler allocates radio resources to each stream taking into account the data transmitted by said processing device.
[Claim 13]
A computer program product comprising program code instructions that can be loaded in a programmable device, the program code instructions causing implementation of the method according to any one of claims 1 to 10 when the program code instructions are run by the programmable device.
[Claim 14]
A storage medium storing a computer program comprising program code instructions, the program code instructions causing implementation of the method according to any one of claims 1 to 10 when the program code instructions are read from the storage medium and run by a programmable device.