On-line distributed TDMA/FDMA/CDMA link assignment in mobile radio networks with flexible directivity
First Claim
1. A method of assigning transmission parameters when establishing a link (i-j) between two nodes i, j in a communications network, whereby potential conflicts and interference with other nodes of the network that neighbor the nodes i, j are avoided, the method comprising the steps of:
- assigning a time slot tk, and a frequency-code value (f, c)1 to a link (i-j) between a pair of nodes i, j, in a communications network, byfirst choosing from a set T an available time slot tk which is not in use for links established between node i and nodes neighboring node i, or for links established between node j and nodes neighboring node j, wherein k connotes a currently chosen time-slot;
second choosing from a set FC an available frequency-code value (f, c)1 which is not, during the chosen available time slot tk, in use by a node that neighbors node i, or by a node that neighbors node j, wherein 1 connotes a currently chosen frequency-code value; and
returning, if no frequency-code value (f, c)1 is available during a chosen time slot tk, to said first choosing step after removing tk from the set T of available time slots;
whereinT is a defined set of available time slots (t) during which links in the communications network can be activated; and
FC is a defined set of frequency-code values (f, c) each of which defines a frequency or a frequency-code pair for association with the links in the communications network.
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Accused Products
Abstract
When establishing a link (i-j) between two nodes i, j in a mobile radio communications network, transmission parameters are assigned such that conflicts and interference with nodes that neighbor the nodes i and j are avoided. A time-slot and a frequency-code value are assigned to the link (i-j) from a defined set of time-slots T, and from a defined set of frequency-code values FC. Set T contains time slots (t) during which links in the network can be activated, and set FC contains frequency-code values (f, c) each of which specifies a frequency or a frequency-code pair for association with the links. A time slot tk is first chosen from set T which slot is not in use for links between node i and nodes neighboring node i, or for links between node j and nodes neighboring node j. A frequency-code value (f, c)1 is next chosen from set FC which value is not in use by any node that neighbors node i or by any node that neighbors node j, during the chosen time slot tk. If no frequency-code value (f, c)1 is available during the chosen time-slot tk, tk is removed from the set T of available time slots and another available time slot is chosen until a frequency-code value (f, c)1 is available for the link (i-j) during the chosen time slot.
68 Citations
17 Claims
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1. A method of assigning transmission parameters when establishing a link (i-j) between two nodes i, j in a communications network, whereby potential conflicts and interference with other nodes of the network that neighbor the nodes i, j are avoided, the method comprising the steps of:
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assigning a time slot tk, and a frequency-code value (f, c)1 to a link (i-j) between a pair of nodes i, j, in a communications network, by first choosing from a set T an available time slot tk which is not in use for links established between node i and nodes neighboring node i, or for links established between node j and nodes neighboring node j, wherein k connotes a currently chosen time-slot; second choosing from a set FC an available frequency-code value (f, c)1 which is not, during the chosen available time slot tk, in use by a node that neighbors node i, or by a node that neighbors node j, wherein 1 connotes a currently chosen frequency-code value; and returning, if no frequency-code value (f, c)1 is available during a chosen time slot tk, to said first choosing step after removing tk from the set T of available time slots;
whereinT is a defined set of available time slots (t) during which links in the communications network can be activated; and FC is a defined set of frequency-code values (f, c) each of which defines a frequency or a frequency-code pair for association with the links in the communications network. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A node structure for each of a number of nodes in a communications network, wherein said structure enables transmission parameters including time slots and frequency-code values to be assigned to a link (i-j) between a pair of nodes i, j to be linked, and avoids potential conflicts and interference with other nodes that neighbor the nodes i, j;
- said node structure comprising;
transmitter means for transmitting information to other nodes including nodes with which a link is desired; receiver means for receiving information from said other nodes; and controller means coupled to said transmitter means and to said receiver means for (a) acquiring through said receiver means information corresponding to existing time slot and frequency-code value assignments at each neighboring node, (b) first choosing from a set T an available time slot tk which is not in use for links established between node i and nodes neighboring node i, or for links established between node j and nodes neighboring node j; (c) second choosing from a set FC an available frequency-code value (f, c)1 which is not, during the chosen available time slot tk, in use by a node that neighbors node i, or by a node that neighbors node j; (d) returning, if no frequency-code value (f, c)1 is available during the chosen time slot tk, to said first choosing step after removing tk from the set T of available time slots; and (e) assigning a chosen time slot tk, and a chosen frequency-code value (f, c)1 for a link (i-j) between the nodes i, j;
whereink denotes a currently chosen time-slot; l denotes a currently chosen frequency-code value; T is a defined set of time slots (t) during which links in the network can be activated, and FC is a defined set of frequency-code values (f, c) each of which specifies a frequency or a frequency-code pair for association with the links in the network. - View Dependent Claims (11, 12, 13, 14, 15)
- said node structure comprising;
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16. A method of dynamically and flexibly dividing a time-slot of a given duration assigned for communication among a pair of nodes in a communications network, comprising;
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allocating a portion of an assigned time-slot tk of given duration T for a first uni-directional link (i→
j), and allocating a remaining portion of the duration T of the time slot tk for a second uni-directional link (i←
j);said allocating steps being carried out by notifying each of the nodes i, j of their aggregate transmission bandwidth requirements, and defining a flexible splitting ratio {Ti→
j ;
Ti←
j } of the time slot duration T for implementing the first and the second uni-directional links, the ratio being equal to
space="preserve" listing-type="equation">{1/2+(λ
.sub.i -λ
.sub.j)/2C};
{1/2-(λ
.sub.i -λ
.sub.j)/2C}wherein the total capacity of bi-directional link (i-j) is C; the aggregate transmission bandwidth needs of nodes i and j are λ
i for unidirectional link i→
j, and λ
j for unidirectional link i←
j;C≧
λ
i +λ
j ; andλ
i ≧
λ
j. - View Dependent Claims (17)
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Specification