Method for multiplexing different bit rate sources
View Patent ↗This invention relates to the multiplexing of multiple sources in a multiplexer. A special arrangement is used for calculating an efficient peak capacity value that guarantees good performance for an outgoing link. The invention uses a method with two phases. The first phase precalculates the capacity of the outgoing link with different numbers of incoming links having equal packet size, and forms a table from the results of the precalculation. In the second phase, the peak capacity needed for the outgoing link is calculated using the precalculated tables.
1. A method comprising:
precalculating, by a multiplexer, arrays of peak capacity values, each array running for several numbers of incoming links, and said each array comprising a specific situation where the incoming links transmit packets within the same size;
dividing the packets coming from the incoming links into parts, and regrouping the parts, each group having a maximum part size, and said each group containing at most one part from any packet;
setting peak capacity values for the groups according to the precalculated arrays;
scaling the peak capacity value of each group by multiplying each group by the maximum part size of that group;
setting the peak capacity value of an outgoing link to be the sum of the scaled peak capacity values of the groups; and
establishing the outgoing link.
2. A method comprising:
precalculating, by a multiplexer, arrays of peak capacity values, each array running for several numbers of incoming links, and said each array comprising a specific situation where the incoming links transmit packets within the same size;
dividing the packets coming from the incoming links into parts, and regrouping the parts, each group having a maximum part size, and said each group containing at most one part from any packet;
wherein, in said dividing of the packets,
the length of a shortest packet defines the length of a first part for the packets coming from all the incoming links,
the length of a part of a next shortest packet, which is left after the first part, defines the length of a second part for the packets coming from the incoming links, except the link transmitting the shortest packets, and
the length of a third and remaining parts are defined correspondingly, until the length of a final part is the length of a remaining part of a longest packet;
setting peak capacity values for the groups according to the precalculated arrays;
scaling the peak capacity value of each group by multiplying each group by the maximum part size of that group;
setting the peak capacity value of an outgoing link to be the sum of the scaled peak capacity values of the groups; and
establishing the outgoing link.
3. A method comprising:
precalculating, by a multiplexer, arrays of peak capacity values, each array running for several numbers of incoming links, and said each array comprising a specific situation where the incoming links transmit packets within the same size;
dividing the packets coming from the incoming links into parts, and regrouping the parts, each group having a maximum part size, and said each group containing at most one part from any packet;
wherein, in the dividing of the packets,
the length of a shortest packet defines the length of a first part for the packets coming from all the incoming links, and
the lengths of remaining parts of the packets are defined as having certain lengths, although the lengths of the parts after the first part are shorter than said certain lengths;
setting peak capacity values for the groups according to the precalculated arrays;
scaling the peak capacity value of each group by multiplying, each group by the maximum part size of that group;
setting the peak capacity value of an outgoing link to be the sum of the scaled peak capacity values of the groups; and
establishing the outgoing link.
4. A method according to claim 1 , wherein, in the dividing of the packets, the lengths of the parts are defined to have certain lengths.
5. A method according to claim 1 , wherein the precalculating uses the formula
Q
D
N
(
x
)
=
∑
x
<
n
≤
N
(
N
n
)
(
n
-
x
D
)
n
(
1
-
n
-
x
D
)
N
-
n
D
-
N
+
x
D
-
n
+
x
where
N=a number of similar incoming links,
D=the number of packets that can be served in a time period between incoming packets in a single link,
x=an allowable queue size,
Q D N (x)=a desired value of loss probability.
6. A method according to claim 1 , wherein there is a low number of incoming links relative to a number of outgoing links.
7. A method according to claim 1 , wherein the outgoing link is an asynchronous transfer mode (ATM) link.
8. A multiplexer arranged to perform steps, wherein the steps comprise:
precalculate arrays of peak capacity values, each array running for several numbers of incoming links, and said each array comprising a specific situation where the incoming links transmit packets within the same size;
divide the packets coming from the incoming links into parts, and regrouping the parts, each group having a maximum part size, and said each group containing at most one part from any packet;
set peak capacity values for the groups according to the precalculated arrays;
scale the peak capacity value of each group by multiplying each group by the maximum part size of that group; and
set the peak capacity value of an outgoing link to be the sum of the scaled peak capacity values of the groups.
9. A method comprising:
precalculating, by a multiplexer, arrays of peak capacity values, each array running for several numbers of incoming links, and said each array comprising a specific situation where the incoming links transmit packets within the same size;
dividing the packets coming from the incoming links into parts, and regrouping the parts, each group having a maximum part size, and said each group containing at most one part from any packet;
setting required peak capacity values for the groups according to the precalculated arrays;
scaling the required peak capacity value of each group by multiplying each group by the maximum part size of that group;
setting the required peak capacity value of an outgoing link to be the sum of the scaled required peak capacity values of the groups; and
establishing the outgoing link.