Dynamic channel assignment cordless telecommunication network

Claim 2

A telecommunication network as claimed in claim 1, wherein said priority value generating means comprises: a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries; means for measuring field intensity of each of said radio channels and increasing the stored priority value of the channel group to which the radio channel belongs if the measured field intensity is higher than a specified value and decreasing said stored priority value of the channel group if the measured field intensity is lower than said specified value; and means for detecting a maximum value of said priority values stored in said priority table and reassigning one of said channel groups having said maximum value to the base unit instead of the channel group currently assigned to the base unit.

Claim 3

A telecommunication network as claimed in claim 1, wherein said priority value generating means comprises: a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries; means for measuring field intensity of each of said radio channels and increasing the stored priority value of the channel group to which the radio channel belongs if the measured field intensity is higher than a specified value and decreasing said stored priority value of the channel group if the measured field intensity is lower than said specified value; means for detecting a maximum value of said priority values stored in said priority table; and means for comparing the detected maximum value with the priority value of the channel group which is currently assigned to the base unit and reassigning one of said channel groups having said maximum value instead of the current channel group if the maximum value is greater than said previous value by more than a predetermined amount.

Claim 4

A telecommunication network as claimed in claim 1, wherein said priority value generating means comprises: a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries; means for (a) measuring field intensity of each of said radio channels, classifying the measured field intensity of each channel as representing one of first, second and third possible states of the channel, (b) determining whether all the measured field intensities simultaneously represent a mixture of said first, second and third possible states of said channels, (c) increasing the stored priority value of the channel group which is currently assigned to the base unit if the measured field intensity of each channel is classified, as representing the third possible state and if all the measured field intensities are determined as representing said mixture of possible states, and (d) decreasing said stored priority value of the currently assigned channel group if the measured field intensity of each channel is classified as representing the first or second possible state and if all the measured field intensities are determined as representing said mixture of possible states, said first, second and third possible states representing respectively an idle state of each channel, a busy state of each channel of the channel group currently assigned to the base unit, and a busy state of each channel of a channel group other than said assigned channel group; and means for detecting a maximum value of said priority values stored in said priority table and reassigning one of said channel groups having said maximum value to the base unit instead of the channel group currently assigned to the base unit.

Claim 5

A telecommunication network as claimed in claim 1, wherein said priority value generating means comprises: a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries; means for (a) measuring field intensity of each of said radio channels, classifying the measured field intensity of each channel as representing one of first, second and third possible states of the channel, (b) determining whether all the measured field intensities simultaneously represent a mixture of said first, second and third possible states of said channels, (c) increasing the stored priority value of the channel group which is currently assigned to the base unit if the measured field intensity of each channel is classified as representing the third possible state and if all the measured field intensities are determined as representing said mixture of possible states, and (d) decreasing said stored priority value of the currently assigned channel group if the measured field intensity of each channel is classified as representing the first or second possible state and if all the measured field intensities are determined as representing said mixture of possible states, said first, second and third possible states representing respectively an idle state of each channel, a busy state of each channel of the channel group currently assigned to the base unit, and a busy state of each channel of a channel group other than said assigned channel group; and means for detecting a maximum value of said priority values stored in said priority table; and means for comparing the detected maximum value with the priority value of the channel group which is currently assigned to the base unit and reassigning one of said channel groups having said maximum value instead of the current channel group if the maximum value is greater than said previous value by more than a predetermined amount.

Claim 6

A telecommunication network as claimed in claim 1, wherein said priority value generating means comprises: a channel status table having entries corresponding respectively to the channels of all of said groups, said channel status table storing busy/idle status bits respectively in said corresponding entries indicating the busy/idle states of said channels; means for receiving a call request to or from said cordless units located in the same zone as the base unit, and updating the busy/idle status bits of the channels of the channel group which is currently assigned to the base unit according to presence and absence of said call request; a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries; means for (a) sequentially retrieving all the busy/idle status bits from said channel status table, (b) classifying each channel of all said groups as representing a first possible state of the channel if the retrieved status bit indicates a busy state of the channel, (c) measuring field intensity of each channel of all said groups if the retrieved status bit indicates an idle busy state of the channel and classifying the channel as representing a second possible state of the channel if the measured field intensity of the channel is lower than a specified value or a third possible state of the channel if the measured field intensity is higher than the specified value, (d) determining whether all the channels are classified as simultaneously representing a mixture of said first, second and third possible states, (e) increasing the stored priority value of the channel group which is currently assigned to the base unit if each channel of all said groups is classified as representing the third possible state and if all channels of said groups are determined as representing said mixture of all possible states, and (f) decreasing said stored priority value of the currently assigned channel group if each channel of all said groups is classified as representing the first or second possible state and if all channels of said groups are determined as representing said mixture of all possible states, said third possible state representing a busy state of each channel of a channel group which is not currently assigned to the base unit; and means for detecting a maximum value of said priority values stored in said priority table and reassigning one of said channel groups having said maximum value to the base unit instead of the channel group currently assigned to the base unit.

Claim 7

A telecommunication network as claimed in claim 6, wherein said maximum value detecting and reassigning means comprises means for retrieving the busy/idle status bits of the channels of the group currently assigned to the base unit and reassigning said one channel group to the base unit if the retrieved status bits simultaneously indicate all idle states of the channels.

Claim 8

A telecommunication network as claimed in claim 1, wherein said priority value generating means comprises: a channel status table having entries corresponding respectively to the channels of all said groups, said channel status table storing busy/idle status bits respectively in said corresponding entries indicating the busy/idle states of said channels; means for receiving a call request to or from said cordless units located in the same zone as the base unit, and updating the busy/idle status bits of the channels of the channel group which is currently assigned to the base unit according to presence and absence of said call request; a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries; means for (a) sequentially retrieving all the busy/idle status bits from said channel status table, (b) classifying each channel of all said groups as representing a first possible state of the channel if the retrieved status bit indicates a busy state of the channel, (c) measuring field intensity of each channel of all said groups if the retrieved status bit indicates an idle bury state of the channel and classifying the channel as representing a second possible state of the channel if the measured field intensity of the channel is lower than a specified value or a third possible state of the channel if the measured field intensity is higher than the specified value, (d) determining whether all the channels are classified as simultaneously representing a mixture of said first, second and third possible states, (e) increasing the stored priority value of the channel group which is currently assigned to the base unit if each channel of all said groups is classified as representing the third possible state and if all channels of said groups are determined as representing said mixture of all possible states, and (f) decreasing said stored priority value of the currently assigned channel group if each channel of all said groups is classified as representing the first or second possible state and if all channels of said groups are determined as representing said mixture of all possible states, said third possible state representing a busy state of each channel of a channel group which is not currently assigned to the base unit; means for detecting a maximum value of said priority values stored in said priority table; and means for comparing the detected maximum value with the priority value of the channel group which is currently assigned to the base unit and reassigning one of said channel groups having said maximum value instead of the current channel group if the maximum value is greater than said previous value by more than a predetermined amount.

Claim 9

A telecommunication network as claimed in claim 8, wherein said maximum value detecting and reassigning means comprises means for retrieving the busy/idle status bill of the channels of the group currently assigned to the base unit and reassigning said one channel group to the base unit if the retrieved status bits simultaneously indicate all idle states of the channels.

Claim 10

A telecommunication network as claimed in any one of claims 1 to 9, further comprising a local switching system connected to a public switched telecommunication network, wherein said base units are connected to said local switching system.

Claim 11

In a telecommunication network for serving cordless units located in a plurality of service zones, said network having radio speech channels which are organized into a plurality of channel groups such that no intermodulation products occur among the channels of each group, said network comprising a plurality of base units located respectively in said service zones, each of said base units comprising means for establishing two-way speech channels with those of the cordless units which are located in the same zone as the base unit, a method for assigning one of said channel groups to each one of said base units comprising the steps of: a) generating priority values of said channel groups as representations of usages of said groups through a statistical process; and b) assigning one of said channel groups to the base unit according to said priority values.

Claim 12

A method as claimed in claim 11, wherein each of the base unit includes a priority table having entries corresponding respectively to said channel groups, said priority table storing priority values of said channel groups respectively in said corresponding entries, wherein the step (a) comprises: a₁) measuring field intensity of each of said radio channels; a₂) increasing the stored priority value of the channel group to which the radio channel belongs if the measured field intensity is higher than a specified value and decreasing said stored priority value of the channel group if the measured field intensity is lower than said specified value; and a₃) detecting a maximum value of said priority values stored in said priority table; and a₄) reassigning one of said channel groups having said maximum value to the base unit instead of a channel group currently assigned to the base unit.

Claim 13

A method as claimed in claim 12, wherein the step (a₄) comprises the steps of comparing the detected maximum value with the priority value of the channel group which is currently assigned to the base unit and reassigning said one of said channel groups if the maximum value is greater than said previous value by more than a predetermined amount.

Claim 14

A method as claimed in claim 12 or 13, wherein the step (a₂) comprises the steps of: A₁) classifying the measured field intensity of each channel as representing one of first, second and third possible states of the channel, A₂) determining whether all the measured field intensities simultaneously represent a mixture of said first, second and third possible states of said channels, said first, second and third possible states representing respectively an idle state of each channel, a busy state of each channel of the channel group currently assigned to the base unit, and a busy state of each channel of a channel group other than said assigned channel group; and A₃) if all the measured field intensities are determined by the step (A₂) as representing said mixture of possible states, increasing the stored priority value of the channel group which is currently assigned to the base unit if the measured field intensity of each channel is classified by the step (A₁) as representing the third possible state and decreasing said stored priority value of the currently assigned channel group if the measured field intensity of each channel is classified by the step (A₁) as representing the first or second possible state.

Claim 15

A method as claimed in claim 11, 12, or 13, wherein each of the base units further comprises a channel status table having entries corresponding respectively to the channels of all said groups, said channel status table storing busy/idle status bits respectively in said corresponding entries indicating the busy/idle states of said channels, wherein the step (a) comprises the steps of: a₁) receiving a call request to or from said cordless units located in the same zone as the base unit, and updating the busy/idle status bits of the channels of the channel group which is currently assigned to the base unit according to presence and absence of said call request; a₂) sequentially retrieving all the busy/idle status bits from said channel status table; a₃) classifying each channel of all said groups as representing a first possible state of the channel if the retrieved status bit indicates a busy state of the channel; a₄) measuring field intensity of each channel of all said groups if the retrieved status bit indicates an idle busy state of the channel and classifying the channel as representing a second possible state of the channel if the measured field intensity of the channel is lower than a specified value or a third possible state of the channel if the measured field intensity is higher than the specified value, said third possible state representing a busy state of each channel of a channel group which is not currently assigned to the base unit; (a₅) determining whether all the channels of said groups are classified as simultaneously representing a mixture of said first, second and third possible states; and (a₆) if all channels of said groups are determined by the step (a₅) as representing said mixture of all possible states, increasing the stored priority value of the channel group which is currently assigned to the base unit if each channel of all said groups is classified by the step (a₃) as representing the third possible state, and decreasing said stored priority value of the currently assigned channel group if each channel of all said groups is classified by the step (a₃) as representing the first or second possible state.

Claim 16

A method as claimed in claim 15, wherein the step (b) comprises the steps of retrieving the busy/idle status bits of the channels of the group currently assigned to the base unit and reassigning said one channel group to the base unit if the retrieved status bits simultaneously indicate all idle states of the channels.