JP2890993B2 - Channel assignment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel allocation method for allocating a channel by applying a time division multiple access system using a plurality of carriers in a radio communication field such as a satellite communication and a mobile communication, and more particularly to a radio channel efficiency. The present invention relates to a channel allocation scheme that enables efficient use.

[0002]

2. Description of the Related Art FIG. 30 is a block diagram showing a satellite communication system to which a time division multiple access system using a plurality of carriers is applied. In the figure, ₁₁ to 1 _L are slave stations having station numbers ₁ to _L for mutual communication, 2 is a control station for controlling communication of these slave stations ₁₁ to 1 _L and allocating channels, and 4 is a control station. Data burst.

[0003] Each carrier f _{1 to} f _M is divided into channels for each of time slots t _{1 to} t _N indicating a time position, and a data burst 4 is transmitted for each channel.

[0004] It is assumed here that the number of carriers is M and the number of time slots is N. Therefore, the total number of channels = MN, and the number of channels per carrier is N.

[0005] Control station 2, for example, slave station 1 ₁ slave station 1 ₂
Upon receiving the channel allocation request occurred call as a communication request to, the channel position to be assigned to the call (position represented by the time slot t _n and the carrier f _m or less, with (t _n, t _m) expressed) was determined, and notifies each the channel (t _n, t _m) to the slave station 1 ₁ and 1 _2.

In the following description, for the sake of simplicity, each slave station 1
_{For 1} to 1 _L, only one carrier can be transmitted and received within one time slot. That is, each slave station 1 ₁ within one time slot
The allowable number of transmission / reception channels of １1 _L is one. Therefore, each slave station 1 ₁ to 1 _L maximum can be received or the number of channels is a channel number = N per carrier.

Conventionally, as this kind of channel assignment system, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 2-44829, and FIG. 31 is a diagram for realizing the conventional first channel assignment system shown in the above document. FIG. 3 is a block diagram showing a configuration of a channel assignment scheme of a control station.

In FIG. 31, reference numeral 5 denotes a station number of a slave station as a transmitting station using each channel (hereinafter referred to as a transmitting station number) and a station number of a slave station as a receiving station (hereinafter referred to as a receiving station number). , A channel management table for managing the specified time slot, and a channel management table 6 for managing an empty channel in the specified time slot. The number-of-used-channels measuring unit 8 checks the total number of transmission channels of the transmitting station and the total number of reception channels of the designated receiving station using the channel management table 5. It is a call control management unit that controls the entire channel assignment process such as designation of a transmitting station and a receiving station to the used channel number measuring unit 7.

Next, a conventional first channel assignment method shown in FIG. 31 will be described with reference to a flowchart of FIG. New from the transmitting station 1 _i of transmission station number i to the receiving station 1 _j of the receiving station number j call (hereinafter, referred to as new call) When is originated, first, in step s1, the call control manager 8
To specify the time slot idle channel search unit 6 selects the time slot t ₁ as an assignment candidate time slot t _a is.

[0010] Next, in step s2, the call control management unit 8, there is an empty channel in the time slot t _1,
And the transmitting station 1 _i and the receiving station 1 _j have their time slots t
It is determined whether any channel in ₁ is not used for transmission and reception, respectively.

First, the time slot empty channel searching section 6 uses the channel management table 5 to execute the time slot t.
Search for empty channels in _one . As a result, if there is an empty channel in the time slot t _1, the call control manager 8
Specifies the time slot t ₁ , the transmitting station number i, and the receiving station number j to the used channel number measuring unit 7.

Thus, the used channel number measuring unit 7 uses the channel management table 5 to calculate the total number of transmission channels used by the transmitting station 1 _i and the number of receiving channels used by the receiving station 1 _j within the time slot t ₁ . Count the total number. As described above, here, each of the slave stations 1 ₁ to 1 _L
Since the allowable number of transmission / reception channels in the time slot is set to one, in this step s2, the used channel number measuring unit 7 checks the presence / absence of transmission by the transmitting station 1 _i and the presence / absence of reception by the receiving station 1 _j . As a result, the transmitting station 1
_{If i} determines that no channel in time slot t ₁ is being used for transmission, and that receiving station 1 _j is not using any channel in time slot t _{1 for} reception,
Proceed to step s3.

In step s3, the call control manager 8
Selects an empty channel in the time slot t ₁ searching for time slot t ₁ from the carrier f ₁ to f _M.

Next, in step s4, the call control manager 8 determines whether or not the required number of channels for a new call has been selected. If the required number of channels is 1, the process proceeds to step s5, where the previously selected channel is selected. An empty channel is assigned as a channel used for a new call, and the transmitting station number i and the receiving station number j are set in the element positions in the channel management table 5 corresponding to the channel to which the new call is assigned, and the operation ends.

[0015] In the above step s2, the call control management unit 8, if it is determined that there is no empty channel in the time slot t _1, or a transmission station 1 _i is used already transmitting a time slot t ₁ If it is determined that the receiving station 1 _j has already used the time slot t ₁ for reception, the process returns to the step s 2 through the steps s 6 and s 7, and thereafter, the allocation candidate time slot time slot t _2, t ₃ as t _a,
.., T _{N in} the same manner as in the case of the time slot t ₁ until an empty channel exists and a time slot not used by the transmitting station 1 _i and the receiving station 1 _j for transmission and reception is found. Repeat the process.

If the required number of channels of the new call is a plurality k, the process returns from step s4 to step s2 via s6 and s7, and returns to steps s2 to s4, s6 and s6 until k empty channels are selected. Repeat s7.

Further, in step s6, it is determined whether or not all the time slots t _{1 to} t _N have been searched. If it is determined that the search has been made, it means that it is impossible to select k required empty channels. , End the operation. In this case, a call loss occurs.

Next, the first conventional channel allocation method will be described in detail with reference to the channel management table shown in FIG. The channel management table 5 has an N × M matrix structure using the total number N of time slots and the total number M of channels, and its element (n, m) has a channel (t _n ,
f _m ) of the call using F _m ). Here, a call from the transmitting station number A to the receiving station number B is represented as (A → B). Here, (0 → 0) indicates an empty channel.

[0019] First, in the channel assignment state of FIG. 33 (a), the example number of required channels from the transmitting station 1 ₁ to the receiving station 1 ₂ to 1 channel call (1 → 2) has occurred.
Upon receiving the channel assignment request, the call control manager 8 sends the time slot t
Specify ₁ .

The time slot empty channel searching section 6
Find the empty channel in the time slot t ₁ using the channel management table 7, finding an empty channel (t _1, f _M).

Next, the call control manager 8 designates the time slot t ₁ , the transmitting station number 1 and the receiving station number 2 to the used channel number measuring section 7. Used channel counting unit 7 uses the channel management table 5, finds that the transmission station 1 ₁ is using already transmitted a channel (t _1, f ₂₎ in the time slot t _1. Therefore, the call control manager 8
It is determined that an empty channel (t ₁ , f _M ) in the time slot t ₁ cannot be selected.

[0022] Then, the call control management unit 8 performs the same processing for the time slot t _2. The call control management unit 8, an empty channel (t _2, f ₂₎ in the time slot t ₂ and (t _2, f _M) finding, but the receiving station 1 ₂ Channel (t
₂ , f ₁ ) are already used for reception, so it is determined that the empty channels (t ₂ , f ₂ ) and (t ₂ , f _M ) cannot be selected.

[0023] Then, the call control management unit 8 performs the same processing for the time slot t _3. The call control manager 8 finds an empty channel (t ₃ , f ₂ ) in the time slot t ₃ . Because the transmission station 1 ₁ and the receiving station 1 ₂ are not used in any channel respectively respectively transmit and receive in the time slot t _3, the call control management unit 8 air channel (t _3, f ₂₎ call Select as (1 → 2) assigned channel.

Since the required number of channels for the call (1 → 2) is one, the call control manager 8 completes the selection of the empty channel and sets the selected empty channel (t ₃ , f ₂ ). The call is assigned to the call (1 → 2) as shown in FIG.

Further, it is assumed that a call (3 → 4) in which the required number of channels is 4 occurs in the assignment state shown in FIG. The call control management unit 8 selects an empty channel (t _1, f ₃₎ in the time slot t _1, an idle channel in the time slot t ₂ of (t _2, f ₂₎ and (t _2, f ₃₎ , And one of the empty channels (t _N , f ₁ ) and (t _N , f _M ) is selected within the time slot t _N , and the number of required channels out of four channels is selected. Although three channels can be selected, the remaining one channel cannot be selected, resulting in a call loss.

As described above, according to the first conventional channel assignment method, first, a time slot is selected, and an empty channel within the selected time slot is selected. Frequent selections tend to bias empty channels toward higher numbered time slots.

Therefore, when a call requiring a plurality of required channels (hereinafter referred to as a high-speed call) occurs, an empty channel cannot be selected from a time slot equal to the required number of channels, and the call loss rate of the high-speed call increases. was there. Next, a description will be given of a second conventional channel assignment method in which this point is improved.

FIG. 34 is a block diagram showing a configuration of a channel assignment method in a control station for realizing the second conventional channel assignment method disclosed in Japanese Patent Application Laid-Open No. 2-44829. In FIG. 34, reference numerals 5, 7 and 8 are the same as those in FIG.
Is an in-carrier empty channel searching unit for searching for an empty channel in the carrier specified by the call control management unit 8.

Next, a second conventional channel allocation method will be described with reference to the flowchart of FIG. Transmitting station 1
Assuming that a new call is generated from _i to the receiving station 1 _j , first,
In step z1, call control and management unit 8 designates a carrier in an empty channel search unit 9 selects a carrier f ₁ as an assignment candidate carrier f _a.

[0030] Then, in step z2, the idle channel search section 9 carriers, empty channels to find the time slot is in the carrier f ₁ using the channel management table 5. As a result, if an empty channel (t _b , f ₁ ) exists in the time slot t _b in the carrier f ₁ , the call control manager 8 sets the time slot t _b and the transmission station number i and Specify the receiving station number j.

Next, in step z3, the used channel number measuring unit 7 uses the channel management table 5 to
Measures the received total number of channels in time slot t _b by the transmission channel Total and receiving stations 1 _j in the time slot t _b by the transmission station 1 _i. As described above, the allowable number of transmission / reception channels in one time slot of each of the slave stations 1 ₁ to 1 _L is set to 1, so that in step z3,
The number-of-used-channels measuring unit 7 checks whether or not the transmitting station 1 _i has transmitted and whether or not the receiving station 1 _j has been present.

As a result, the call control management unit 8 sets the transmitting station 1 _i
Does not use any channel in the time slot t _{1 for} transmission, and also determines that the receiving station 1 _j does not use any channel in the time slot t _{1 for} reception.

At step z4, the call control manager 8
Selects the empty channel (t _b , f ₁ ) as the channel to be assigned to a new call.

Next, at step z5, the call control manager 8 determines whether the required number of channels for the new call has been selected. If the required number of channels is 1, the process proceeds to step z6, where the previously selected channel is selected. An empty channel is allocated as a channel used for a new call, and the transmitting station number i and the receiving station number j are set at the element positions in the channel management table 5 corresponding to the channel to which the new call has been allocated, and the operation ends.

In step z3, the call control manager 8 determines whether the transmitting station 1 _i has already used the time slot t ₁ for transmission or the receiving station 1 _j has used the time slot t ₁ for receiving. If so, step z7
Returning to step z2 through, step z2, z3 until retrieves all time slots for carrier f ₁
And z7 are repeated. Then, in step z7,
Proceeds to step z8 when it is judged that the search for all all time slots of the carrier f _1, returns to step z2 via step z9, since, carrier f ₂ as an assignment candidate carrier f _a, f _3, ... , choose f _N, repeats the same processing as in the case of carrier f ₁ described above transmitting station 1 _i and the receiving station 1 _j until it finds a time slot that is not used for transmission and reception, respectively.

If it is determined in step z5 that the number of required channels for a new call is a plurality of k, step z5
Through steps z7, z8 and z9 to step z2
And until k empty channels are selected,
The above steps z2 to z5 and z7 to z9 are repeated.

Further, in step z8, it is determined whether or not all the time slots t _{1 to} t _N have been searched. If it is determined that the search has been made, it is determined that the number of empty channels equal to the required number k of channels cannot be selected. Yes, end operation. In this case, it is a call loss.

Next, a second conventional channel allocation method will be described.
This will be specifically described with reference to the channel management table shown in FIG. First, in the channel assignment state shown in FIG. 33 (a), the number of the required channel to the receiving station 1 ₂ from the transmission station 1 ₁ is 1 channel call (1 → 2) has occurred. Upon receiving the channel assignment request, the call control manager 8 specifies the carrier f ₁ to the carrier empty channel searcher 9.

The in-carrier empty channel searching section 9 searches for an empty channel in the carrier f ₁ using the channel management table 7 and finds an empty channel (t _N , f ₁ ).

Next, the call control manager 8 specifies the time slot t _N , the transmitting station number 1 and the receiving station number 2 to the used channel number measuring section 7. Used channel counting unit 7 uses the channel management table 5, that the transmission station 1 ₁ and the receiving station 1 ₂ are not used for any channel of the respective respectively transmit and receive in the time slot t _N Find out. As a result, the call control manager 8 selects the empty channel (t _N , f ₁ ) as the assigned channel for the call (1 → 2).

Since the required number of channels for the call (1 → 2) is one, the call control manager 8 completes the selection of the empty channel and sets the selected empty channel (t _N , f ₁ ). The call is assigned to the call (1 → 2) as shown in FIG.

Further, it is assumed that a call (3 → 4) in which the required number of channels is four occurs in the assignment state shown in FIG. The call control management unit 8, as in the case described above, an empty channel in the time slot t ₂ within the carrier _{f 2 (t 2, f 2} ) and the empty channel in the time slot t ₃ (t _3, f ₂ ) is selected, to select within the carrier f _M empty channel in the time slot _{t 1 (t 1, f M} ) empty channel (t _N in time slot t _N, the f _M), the required channels 4 You can choose everything.

As described above, in the second conventional channel allocation method, first, a carrier is selected, and an empty channel in the selected carrier is selected. Therefore, the number of empty channels in each time slot is averaged. Since an empty channel is easily selected from time slots corresponding to the number of channels required for a high-speed call, the loss rate of the high-speed call is reduced.

[0044]

The channel assignment method in the conventional multi-carrier hopping TDMA system is configured as described above. Therefore, the first channel assignment method increases the loss rate of a high-speed call. Thus, the conventional second channel allocation method can reduce the loss rate of a high-speed call as compared with the first channel allocation method.

However, in the case described below, both the first and second conventional channel allocation methods cause a call loss. For example, the channel management table shown in FIG.
When in the assignment state shown in (a), FIG.
The difference from the previously described FIG. 33A is that the call (2 →→) assigned to the channel (t ₃ , f ₁ ) in FIG.
3) is that it is allocated to the channel (t ₃ , f ₂ ) in FIG. 36A, and the other is the same. In the assignment state of FIG.
Like the example of (a), a new call (1 → 2) is to have occurred from the transmitting station 1 ₁ to the receiving station 1 _2. First, according to the first conventional channel assignment method, a new call (1 → 2) is assigned to the channel (t ₃ , f ₁ ) by the processing described above, as shown in FIG. . On the other hand, the conventional second
Also, according to the channel allocation method described above, a new call (1 → 2) is processed by the above-described process, as shown in FIG.
Assigned to channel (t ₃ , f ₁ ).

[0046] Further, in the case of the allocation state of FIG. 36 (b), the required number of channels from the transmitting station 1 ₃ to the receiving station 1 ₄ 4
It is assumed that a new call (3 → 4) of the channel has occurred. In this case, according to the conventional first channel assignment method, the selected idle channel (t _1, f _M) is in the time slot t _1, an idle channel in the time slot _{t 2 (t 2, f 2} )
And (t ₃ , f _M ) are selected, and one of the empty channels (t _N , f ₁ ) and (t _N , f _M ) is selected in the time slot t _N. , Three of the required four channels can be selected, but the remaining one cannot be selected, resulting in a call loss. On the other hand, according to the conventional second channel assignment scheme, idle channel within the carrier f ₁ (t _N,
f ₁₎ is selected, air channel (t ₂ within the carrier f _2,
f ₂₎ is selected, air channel (t ₁ within the carrier f _M,
f _M ), and three of the required four channels can be selected, but the remaining one cannot be selected, resulting in a call loss . If it happens next
Other available calls to account for possible calls
Channel, for example, an empty channel as shown in FIG.
(T _N , f ₁ ) and assign to new call (1 → 2)
If the number of required channels that occurred next is 4
The call (3 → 4) could be assigned without causing a call loss.

As described above, the conventional first channel assignment method searches for the allocable channel by searching in the carrier direction sequentially from the time slot with the smallest number, while the conventional second channel assignment method finds the available channel with the small number. Find empty channels that can be assigned in the time slot direction in order from the carrier. In the first and second channel allocation schemes of the related art, the first available channel is searched and found, and an empty channel that can be allocated is selected.

As described above, allocable empty channels are selected in the order in which they are found without considering the rate at which the next call to be allocated cannot be allocated, so that a more appropriate allocable empty channel can be overlooked. There is a first problem that the loss rate of a high-speed call increases.

Further, the conventional first and second channel allocation schemes have the following disadvantages when there is a bias in the traffic volume between slave stations.
The second is that the call loss rate of the station where traffic is concentrated increases.
Issues. The above-mentioned second problem will be described below using a specific example.

For example, a case where the traffic volume from the station 1 to the station 2 is larger than the other traffic volumes and the rate at which calls (1 → 2) occur is greater than the rate at which other calls occur will be described. I do. For example, when the channel management table is in the state shown in FIG.
Assume that 2) has occurred. In the above-described conventional two channel allocation methods, each of the new calls (3 → 2) has the channel position (t ₂ , f ₁ ) as shown in FIG.
Assigned to. Next, in the state shown in FIG. 22B, even if a call (1 → 2) having a high rate of occurrence occurs, there is no vacant channel that can be allocated to the call (1 → 2). 2) results in a call loss.
Here, considering that there is a high possibility that the call (1 → 2) will occur, the previous new call (3 → 2) is changed as shown in FIG.
If the call is assigned to the channel position (t _N , f ₂ ) as shown in (c), when a call (1 → 2) which is likely to occur occurs, the time slot t ₂ shown in FIG. (T ₂ , f ₁ ) or (t ₂ , f ₃ )
Could be assigned to any of That is, as shown in the above example, in the conventional channel allocation method of allocating a channel without considering the next call to occur despite the high possibility that a call (1 → 2) occurs,
There is a second problem that the call loss rate of a station where traffic is concentrated increases.

The present invention has been made in order to solve such a problem. When performing a multi-way traffic operation in which a low-speed call having a required number of channels of 1 and a high-speed call having a plurality of required channels coexist, the call loss rate of the high-speed call is reduced. It is an object of the present invention to obtain a channel allocation scheme capable of suppressing an increase in the number of channels.

Another object of the present invention is to provide a channel allocation method capable of suppressing an increase in the call blocking rate of a station where traffic is concentrated, even when the traffic volume between slave stations is uneven.

[0053]

According to a first aspect of the present invention, there is provided a channel assignment system using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots. A plurality of slave stations that transmit and receive bursts containing information data and communicate with each other, manage the use status of the plurality of channels, and assign a new call newly generated from among the plurality of slave stations. In a time division multiple access system using a plurality of carriers including a control station assigned to an empty channel in a time slot, the control station manages the use state of the plurality of channels, and a new call occurs. At this time, the total number of transmission channels used by the transmitting station of the new call in one time slot of the plurality of time slots and the number of transmission channels in the one time slot The number-of-used-channels measuring means for measuring the total number of receiving channels used by the receiving station of the new call, the vacant channel searching means for searching for a vacant channel in the one time slot, and the above-mentioned managed by the channel managing means Assignment pattern extracting means for extracting all possible assignment patterns for the new call at the time when the new call occurs, based on the use state of the plurality of channels, Allocatable call number measuring means for measuring the total number of allocatable calls, and call control management for selecting an allocation pattern having the largest measured total number of allocatable calls and allocating a new call according to the allocation pattern Means.

Further, according to the channel allocation method according to the second aspect of the present invention, a burst including information data is transmitted and received by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots. A plurality of slave stations performing communication and a control station that manages the use state of the plurality of channels and allocates a new call newly generated from among the plurality of slave stations to an empty channel in an allocatable time slot. In a time division multiple access system using a plurality of carriers, the control station manages the use state of the plurality of channels, and one time slot among the plurality of time slots when a new call occurs. , The total number of transmission channels used by the transmitting station of the new call and the receiving channels used by the receiving station of the new call within the one time slot. A new call based on the use state of the plurality of channels managed by the channel management means, a use channel number measurement means for measuring the total number of channels, a free channel search means for searching for a free channel in the one time slot, At the time of occurrence, the number of calls that can be allocated to an empty channel in an allocatable time slot and the number of calls that can be allocated under the assumption that a new call has been allocated to an empty channel in an allocatable time slot are measured. Means for measuring a decrease in the number of allocatable calls which is caused by allocating the new call to the allocatable time slot; The new call is selected in the available channel in the selected allocatable time slot in the order of decreasing number. Assigned is obtained by so and a call management control means.

According to a third aspect of the present invention, in the channel allocation method according to the second aspect, the decrease in the number of allocatable calls is measured by the number of assignable calls reduction means. This is calculated based on the number of channels used in the appropriate time slot and the number of slave stations using the channels in the allocatable time slot.

Further, according to a channel assignment method according to a fourth aspect of the present invention, a burst including information data is transmitted and received by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots. A plurality of slave stations performing communication and a control station that manages the use state of the plurality of channels and allocates a new call newly generated from among the plurality of slave stations to an empty channel in an allocatable time slot. In a time division multiple access system using a plurality of carriers, the control station manages the use state of the plurality of channels, and one time slot among the plurality of time slots when a new call occurs. , The total number of transmission channels used by the transmitting station of the new call and the receiving channels used by the receiving station of the new call within the one time slot. Channel number measuring means for measuring the total number of channels, vacant channel searching means for searching for a vacant channel in the one time slot, and use state of the plurality of channels managed by the channel managing means when a new call occurs Based on the number of vacant channels in the allocable time slot, based on the measurement result of the vacant channel number measuring means, the allocable time slot having a plurality of vacant channels. Of the available channels, the available channels are selected in the order from the smallest number, the available channels in the allocable time slot having the selected plurality of available channels are allocated to the new call, and the required number of channels of the new call are allocated to the plurality of available channels. If not assigned to an allocatable timeslot with a channel, the number of missing channels of the new call Free channel number is obtained by so and a call control management means for allocating the idle channel assignable time slots is one.

Further, according to a channel assignment method according to a fifth aspect of the present invention, a burst including information data is transmitted and received by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots. A plurality of slave stations performing communication and a control station that manages the use state of the plurality of channels and allocates a new call newly generated from among the plurality of slave stations to an empty channel in an allocatable time slot. In a time division multiple access system using a plurality of carriers, the control station manages the use state of the plurality of channels, and one time slot among the plurality of time slots when a new call occurs. , The total number of transmission channels used by the transmitting station of the new call and the receiving channels used by the receiving station of the new call within the one time slot. A time slot in which there is a vacant channel that can be allocated using the used channel number measuring means based on the used state of the plurality of channels managed by the channel managing means; In a state in which a new call is allocated to a vacant channel in an allocatable time slot searched by the vacant channel Assignable call count measuring means for measuring the number of channels that can be assigned to each call,
A traffic parameter measuring means for monitoring a channel assignment request from each slave station to measure a traffic amount between the stations, and an assignable channel number measured by the assignable call number measuring means, the traffic parameter measuring means Based on the measured traffic volume, weight assignable call number generating means for weighting, and the number of channels that can be assigned to a call that may occur next ,
The total number of assignable channels is obtained by weighting each by the weight assignable call number generation means,
A call control management means for selecting a time slot in descending order of the total number of assignable channels and allocating a free channel in the time slot to a new call.

According to a sixth aspect of the present invention, there is provided a channel assignment system according to the fifth aspect, wherein a call weighting coefficient for weighting the number of channels to which a call can be assigned is determined by using the call weighting factor. And a weight assignable call number generating means for obtaining the sum of the occurrence ratios of calls of the same transmitting station and the same receiving station, and weighting the sum with this weighting coefficient.

In a channel assignment method according to a seventh aspect of the present invention, a burst including information data is transmitted and received by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots. A plurality of slave stations performing communication and a control station that manages the use state of the plurality of channels and allocates a new call newly generated from among the plurality of slave stations to an empty channel in an allocatable time slot. In a time division multiple access system using a plurality of carriers, the control station manages the use state of the plurality of channels, and one time slot among the plurality of time slots when a new call occurs. , The total number of transmission channels used by the transmitting station of the new call and the receiving channels used by the receiving station of the new call within the one time slot. A time slot in which there is a vacant channel that can be allocated using the used channel number measuring means based on the used state of the plurality of channels managed by the channel managing means; In a state in which a new call is allocated to a vacant channel in an allocatable time slot searched by the vacant channel Assignable call count measuring means for measuring the number of channels that can be assigned to each call,
A traffic light measuring means connected to a channel management table managed by the channel managing means for measuring the traffic of each call; and a weighting obtained based on the traffic of each call measured by the traffic light measuring means. Using the coefficient, the assignable call number generating means for weighting, and the assignable channel number for the call which may occur next can be assigned after weighting by the weight assignable call number generating means. A call control management means for obtaining a total number of channels, selecting a time slot in descending order of the total number of assignable channels, and allocating an empty channel in the time slot to a new call.

Further, according to the channel allocation method of the present invention, a burst including information data is transmitted and received by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots. A plurality of slave stations performing communication and a control station that manages the use state of the plurality of channels and allocates a new call newly generated from among the plurality of slave stations to an empty channel in an allocatable time slot. In a time division multiple access system using a plurality of carriers, the control station manages the use state of the plurality of channels, and one time slot among the plurality of time slots when a new call occurs. , The total number of transmission channels used by the transmitting station of the new call and the receiving channels used by the receiving station of the new call within the one time slot. A time slot in which there is a vacant channel that can be allocated using the used channel number measuring means based on the used state of the plurality of channels managed by the channel managing means; In a state in which a new call is allocated to a vacant channel in an allocatable time slot searched by the vacant channel Assignable call count measuring means for measuring the number of channels that can be assigned to each call,
A weighting coefficient storage table for storing a preset value, weighting assignable call number generating means for weighting using a weighting coefficient obtained based on the weighting coefficient storage table, and a call that may occur next. The total number of allocatable channels is obtained after weighting the number of channels that can be allocated to the above by the weightable allocatable call number generation means, and a time slot is selected in descending order of the total number of allocatable channels. Call control management means for allocating a free channel in the time slot to a call.

[0061]

In the channel assignment system according to the first aspect of the present invention, a new call is generated by the assignment pattern extraction means based on the use state of a plurality of channels managed by the channel management means. By extracting all possible allocation patterns for the new call, and by measuring the total number of calls that can be allocated to all the extracted allocation patterns by the allocatable call number measuring means, It is possible to select an allocation pattern having the largest measured total number of allocatable calls and allocate the new call according to the allocation pattern.

Further, in the channel allocation method according to the second aspect of the present invention, when a new call is generated by the number-of-allocable-calls reduction number measuring means based on the use state of a plurality of channels managed by the channel managing means. Measuring the number of allocatable calls in an allocatable time slot in the allocatable time slot and the number of allocatable calls in a state where it is assumed that an empty channel in the allocatable time slot is allocated to a new call; A decrease in the number of assignable calls caused by assigning a new call to the assignable time slot can be measured, and the assignable time slot is assigned to the assignable call number by call management control means. In order of decreasing number of
An empty channel in the selected allocatable timeslot can be allocated to the new call.

According to a third aspect of the present invention, in the channel allocation method according to the second aspect of the present invention, in the channel allocation method according to the second aspect, the decrease in the number of assignable calls is measured by the assignable number of calls. It can be calculated based on the number of channels used in the appropriate time slot and the number of child stations using the channels in the allocatable time slot.

In the channel assignment method according to claim 4 of the present invention, the number of available channels can be assigned based on the use state of a plurality of channels managed by the channel management means when a new call has occurred. By measuring the number of empty channels in the time slot, the assignable time slots having a plurality of empty channels are selected in order from the one with the smallest number of empty channels based on the measurement result of the above-mentioned empty channel number measuring means. An empty channel in an allocatable time slot having a plurality of selected empty channels can be assigned to a new call. If the number of empty channels equal to the number of required channels cannot be allocated to the new call, empty channels in an allocatable time slot in which the number of empty channels is 1 can be allocated by the number of insufficient channels.

Further, in the channel assignment system according to the fifth aspect of the present invention, the assignable call number measuring means includes:
With the available channels in the allocatable time slots allocated to the new call, the number of channels that can be allocated to all the calls that may occur next is measured, and the traffic parameter measuring means The channel allocation request from the slave station is monitored to measure the traffic volume between each station, and the weighted allocable call count generating means calculates the above-mentioned measured number of allocable channels by the above-mentioned measured traffic volume. more be weighted based on the number of allocatable channels for the next call that may occur, the total sum of the assignable number of channels from the weighted respectively by the weighting allocatable call number generation means, A time slot is selected in descending order of the total number of assignable channels, and the time slot is assigned to a new call. Free channel of the can be assigned.

According to a sixth aspect of the present invention, there is provided a channel assignment system according to the fifth aspect, wherein the weight assignable call number generation means of the channel assignment system according to the fifth aspect assigns a weight to the number of assignable channels of the call. Is obtained as the sum of the occurrence ratios of calls of the same transmitting station and the same receiving station of the call, and weighting can be performed by the weighting coefficient.

In the channel allocation method according to the seventh aspect of the present invention, the available channel in the allocatable time slot searched by the available channel in time slot search means is converted into a new call by the allocatable call number measuring means. In the allocated state, the number of channels that can be allocated to all the calls that may occur next is measured, and the traffic volume measuring unit is connected to the channel management table managed by the channel managing unit. the traffic intensity of each call is measured, and, by the weighting allocatable call number generation means, more be weighted using a weighting factor determined based on the traffic density of each call, which is above the measurement,
Next, the total number of allocatable channels is obtained after weighting the number of channels that can be allocated to a call that may occur next by the weightable allocatable call number generation means. It is possible to select time slots in descending order and allocate a free channel in the time slot to a new call.

In the channel allocation method according to the eighth aspect of the present invention, the available channel in the allocatable time slot searched by the available channel in time slot search means by the allocatable call number measuring means is converted to a new call. In the allocated state, the number of channels that can be allocated to all the calls that may occur next is measured, and a preset value is stored in a weighting coefficient storage table. by the generation means, more be weighted using the weighting coefficients obtained from the weighting coefficient storage table, the number of allocatable channels for the next call that may occur, by the weighting allocatable call number generation means The total number of assignable channels is obtained after weighting, and the assignable Select the time slots in the order number of summation is large Yaneru can allocate a free channel in the time slot to the new call.

[0069]

Embodiments of the present invention will be described below. Embodiment 1 FIG. FIG. 1 shows a first embodiment of a channel assignment system in a control station for realizing the channel assignment system of the present invention.
FIG. 3 is a configuration block diagram illustrating FIG. 2 is a flowchart illustrating the operation of FIG. In FIG. 1, 5, 6,
Reference numerals 7 and 8 are the same as those of the conventional system shown in FIG. 31, and are respectively a channel management table as a channel management unit, an empty channel search unit in a time slot as an empty channel search unit, and the number of used channels as a used channel measurement unit. A measurement unit and a call control management unit as a call control management unit, 19 is an allocation pattern extraction unit as an allocation pattern extraction unit that extracts all possible allocation patterns for a new call that has occurred, and 20A is an allocation pattern extraction unit This is an allocatable call number measuring unit that measures the total number of allocatable calls for each of the patterns.

Next, a channel assignment method according to the first embodiment will be described with reference to the flowchart of FIG. Transmitting station 1
Assuming that a new call (i → j) has occurred from _i to the receiving station 1 _j , first, at step w 1, the call control manager 8 uses the number-of-used-channels measuring unit 7 and the time-slot free channel searching unit 6. After searching for an allocatable time slot position for a new call (i → j), the allocation pattern extraction unit 19 extracts all possible allocation patterns. Next, in step w2, the allocatable call number measuring unit 2
OA measures the total number of calls that can be allocated to all the extracted allocation patterns. Next, in step w3, the call control management unit 8 selects an allocation pattern in which the measured total number of assignable calls is the largest, and allocates a new call (i → j) according to the selected pattern. The transmitting station number i and the receiving station number j are stored in the element positions in the channel management table 5 corresponding to the allocated channel positions.
Is set and the operation ends.

Next, the channel assignment method according to the first embodiment will be specifically described with reference to a channel management table shown in FIG. First, the channel management table in the channel assignment state of FIG. 36 (a), the the number of required channels to the receiving station 1 ₂ from the transmission station 1 ₁ has occurred a new call (1 → 2) of one channel. The call control management unit 8
When a channel assignment request is received, the time slot t ₁ is designated to the time slot free channel search unit 6. The free slot in time slot search unit 6 searches the free channel in the time slot t ₁ using the channel management table 5 to find a free channel (t ₁ , f _M ).

Next, the call control manager 8 designates the time slot t ₁ , the transmitting station number 1 and the receiving station number 2 to the used channel number measuring section 7. Used channel counting unit 7 uses the channel management table 5, issues Heading that the transmission station 1 ₁ is using already transmitted a free channel in the time slot _{t 1 (t 1, f 2} ). Thus, call control and management unit 8 channels in time slots t ₁ (t _1,
f _M ) is determined to be unselectable.

Next, when the same processing is performed for the time slot t ₂ , the vacant channel searching unit 6 in the time slot
Finds vacant channels (t ₂ , f ₂ ) and (t ₂ , f _M ), but in time slot t ₂ , channels (t ₂ , f _M )
Since ₁₎ is already used for reception by the receiving station 1 _2, free channel of the call control management unit 8 in the time slot t ₂ (t _2, f ₂₎ and (t _2, f _M) of the non-selectable Judge. Then, perform the same processing for the time slot t _3. The call control manager 8 determines the time slot t
Free channel in the ₃ (t _3, f ₁₎ is a new call (1 → 2)
Is found to be assignable to The call control manager 8 notifies the allocation pattern extractor 19 that the empty channel (t ₃ , f ₁ ) in the time slot t ₃ can be allocated to a new call (1 → 2). Further, the same processing as described above is performed for the time slot t _N. The call control management unit 8 issues Heading the vacant channel in the time slot _{t N (t N, f 1} ) and (t _N, f ₃₎ can be allocated to the new call (1 → 2). Vacant channel in the time slot t _N to the call control management unit 8 assignment pattern extraction unit 19 (t _N,
f ₁ ) and (t _N , f ₃ ) can be assigned to a new call (1 → 2).

[0074] By the above processing, it assignment pattern extraction unit 19 with two time slots of t ₃ and t _N in the presence of assignable idle channel for a new call, further vacant channel in the time slot t ₃ ( t ₃ , f
_1), free channel in the time slot t _N (t _N,
It is known that f ₁ ) and (t _N , f ₃ ) are allocatable free channels. Next, the allocation pattern extraction unit 19 selects an empty channel (t ₃ , f ₁ ) in the time slot t ₃ as a first allocation pattern, and selects a new call (1 →→).
FIG. 36 shows a pattern in which 2) is assigned to this empty channel.
Create as shown in (b). Next, the allocation pattern extraction unit 19 selects an empty channel (t _N , f ₁ ) in the time slot t _N as a second allocation pattern, and assigns a pattern in which a new call (1 → 2) is allocated to this empty channel. It is created as shown in FIG. here,
The other free channel (t _N , f _M ) in the time slot t _N may be selected.
_N , f ₁ ) has been shown as an example. Thus, in the above example, there are a total of two types of allocation patterns shown in FIGS. 36 (b) and 36 (c).

Next, the allocatable call number measuring section 20A measures the total number of calls that can be allocated to each of the two allocation patterns created by the pattern extracting section 19. Here, a description will be given of a case where the total number of calls that can be assigned is, for example, the number of child stations is 5. FIG. 3B is a diagram in which the number of calls that can be assigned to the assignment pattern of FIG.
With respect to (2), the number of calls that can be assigned to a call (3 → 2) is 2 since the channels can be simultaneously assigned to the empty channels in the two time slots t ₁ and t _N in FIG. The elements in the 3 rows and 2 columns of the matrix in b) are 2. The total number of calls that can be assigned is the sum of the number of elements in this matrix. Therefore, the total number of calls that can be allocated to the allocation pattern of FIG. Similarly, the number of calls that can be assigned to the assignment pattern of FIG. 36C is represented by a matrix in FIG. 3C, and the total number of calls that can be assigned is 36. Next, the call control management unit 8 selects the assignment pattern in which the total number of assignable calls measured by the assignable call number measuring unit 20A is the largest, but in the above example, the assignment pattern in FIG. Since the total number of assignable calls is larger than the allocation pattern shown in FIG. 36 (b), the allocation pattern shown in FIG. 36 (c) is selected.

As described above, it is possible to select a channel position (t _N , f ₁ ) that has not been selected in the conventional first and second channel allocation methods. Further, in the assignment state shown in FIG.
Even if a channel call (3 → 4) occurs, all the required number of channels can be selected from the four time slots, and the loss rate of a high-speed call can be reduced.

Embodiment 2 FIG. The second embodiment is a channel allocation method that simplifies the processing of the first embodiment and reduces the loss rate of a high-speed call as in the first embodiment. That is, in the first embodiment,
Although all possible allocation patterns for a new call have been extracted, the second embodiment focuses on each one time slot, and assumes that a new call is allocated to the time slot of interest. In this method, the number of possible calls is reduced, time slots are selected in order from the time slot with the smallest measured reduction, and a free channel in the selected time slot is assigned to a new call. According to the second embodiment, for example, even if the new call is a high-speed call and the channel assignment pattern that can be assigned from a plurality of channels at the same time becomes larger than the number of time slots, Since the number of times the number of reductions is measured is at most equal to the number of time slots, there is an advantage that processing related to channel assignment is simplified.

FIG. 4 is a block diagram showing a second embodiment of the present invention. In the figure, reference numerals 5, 6, 7 and 8 are the same as those in FIG. 31 of the conventional system. And a call control management unit 21 as a call control management unit. Assuming that a new call has been assigned to an empty channel in a time slot designated by the call control management unit 8, This is an assignable call number decrease number measuring unit as an assignable call number decrease number measuring unit for measuring the decrease number of assignable calls at the time using the channel management table 5.

Next, the channel assignment operation according to the second embodiment will be described with reference to the flowchart of FIG. Transmitting station 1
Assuming that a new call is generated from _i to the receiving station 1 _j , first,
In step u1, the call control management unit 8 to select and specify the time slot t ₁ as an assignment candidate timeslot ta to the time slot idle channel search unit 6.

[0080] Then, in step u2, time slot free channel search unit 6, there is an empty channel in the time slot t ₁ using the channel management table 5 and the transmission station 1 also any channel in time slot t _{1 i}
And whether the receiving station 1 _j is not using it for transmission and reception, respectively. At that time, the call control management unit 8 first specifies the time slot t ₁ to the time slot free channel search unit 6. The time slot empty channel search unit 6 uses the channel management table to
Search for empty channels in _one .

As a result, if an empty channel exists in the time slot t ₁ , the call control manager 8 specifies the time slot t ₁ , the transmitting station number i and the receiving station number j to the used channel number measuring section 7. I do. As a result, the used channel number measuring unit 7 uses the channel management table to transmit
_i measures the received total number of channels by the transmission channel Total and receiving station 1 _j by.

As described above, each of the slave stations 1 ₁ to 1
_Since the allowable number of transmission / reception channels within one time slot according to _L is one channel, in step u2, the number-of-used-channels measuring unit 7 checks the presence / absence of transmission of the transmitting station 1 _i and the presence / absence of the receiving station 1 _j . As a result, the call control manager 8 determines that the transmitting station 1 _i does not use any channel in the time slot t ₁ for transmission, and the receiving station 1 _j does not receive any channel in the time slot t ₁ . When it is determined that it is not used, the process proceeds to step u3.

[0083] Then, in step u3, call control and management unit 8, time slots t ₁ is selected as assignable time slots, can be allocated call number decreased number measurement unit 21 can assign the selected time slot t ₁ the transmitting station Number i
And the receiving station number j is specified, and the process proceeds to step u4.

In step u 4, the assignable call number decrease count measuring unit 21 uses the channel management table 5
Assume that assigns a new call to the empty channel in the time slot t _1, the number of this time can not be assigned to the time slot t ₁ the call is measured, and notifies the call control management unit 8.

Here, the number of calls is, for example, (1 → 2), (1 → 3),..., (5 → 4) in a multicarrier hopping TDMA system having 5 slave stations. 4 × 5 = 20 types in total. The decrease in the number of allocatable calls is the difference between the number of allocatable calls in a state before a new call is allocated from the 20 types of calls and the number of allocatable calls when it is assumed to have been allocated.

It is assumed that steps u2 to u4 are repeated in the order of time slots t ₂ , t ₃ ,..., T _N through steps u5 and u9, and a new call is allocated to an empty channel in the allocatable time slot. Then, the number of calls that cannot be allocated to the allocatable time slot is measured, and this is notified to the call control management unit 8.

Next, in step u5, it is determined whether or not all the time slots have been searched. If it is determined that the search has been made, the process proceeds to step u6.

At step u6, the call control manager 8
Selects an empty channel in an allocatable timeslot with the smallest decrease in the number of allocatable calls.

Next, at step u7, the call control manager 8 determines whether or not the required number of channels for the new call has been selected. If the required number of channels is 1, the process proceeds to step u8, where the previously selected channel is selected. An empty channel is allocated as a channel used for a new call, and the transmitting station number i and the receiving station number j are set at the element positions in the channel management table 5 corresponding to the channel to which the new call has been allocated, and the operation ends.

[0090] In the above step u2, if there is no empty channel in the time slot t ₁ or a transmission station 1 _i
Has already used time slot t ₁ for transmission, or if receiving station 1 _j has already used time slot t ₁ for reception, the process returns to step u2 via steps u5 and u9. , Allocation candidate time slot t
time slot t _2, t ₃ as _a, ..., choose t _N, the time slot t ₁ the above transmission station 1 _i and the receiving station 1 _j until it finds a time slot not used for transmission and reception, respectively The same process is repeated.

If the required number of channels of the new call is a plurality of k, the process proceeds from step u7 to step u11 via step u10, and assignable time slots in which the number of assignable calls decreases by the next smallest number. Steps u7 to u1 until the selection and k empty channels are selected.
Repeat 1. That is, k time slots are selected in ascending order from the time slot with the smallest decrease in the number of assignable calls, and a new call is assigned to an empty channel in the selected assignable time slot.

Next, in step u10, it is determined whether or not all the time slots t _{1 to} t _N have been searched.
If it is determined that the search has been made, it means that there is a channel that has not been allocated to an empty channel among the k required channels, and the operation ends. In this case, a call loss occurs.

Next, the channel assignment method according to the second embodiment will be specifically described with reference to the channel management table shown in FIG. First, in the channel assignment state of FIG. 36 (a), the number of required channels to the receiving station 1 ₂ from the transmission station 1 ₁ is to have occurred a call (1 → 2) of one channel. When receiving the channel assignment request, the call control manager 8 specifies the time slot t ₁ to the empty channel in time slot search unit 6. The time slot empty channel search unit 6 searches for an empty channel in the time slot t ₁ using the channel management table, and finds an empty channel (t ₁ , f _M ).

Next, the call control manager 8 specifies the time slot t ₁ , the transmitting station number 1 and the receiving station number 2 to the used channel number measuring section 7. Used channel counting unit 7 uses the channel management table 5, finds that the transmission station 1 ₁ is using channel in time slot t ₁ the (t _1, f ₂₎ already transmitting. Therefore, the call control manager 8
It is determined that an empty channel (t ₁ , f _M ) in the time slot t ₁ cannot be selected.

Next, the same processing is performed for the time slot t ₂ , and the time slot empty channel searching section 6 finds empty channels (t ₂ , f ₂ ) and (t ₂ , f _M ). channel in the ₂ (t _2, f ₁₎
Since There has already been used for reception by the receiving station 1 _2, the call control management unit 8 air channel (t _2, f ₂₎ and (t _2,
f _M ) is determined to be unselectable.

Next, the same processing is performed for the time slot t ₃ , and the time slot empty channel searching section 6
Finds an empty channel (t ₃ , f ₁ ). Call control manager 8
Indicates to the used channel number measuring section 7 that the empty channel (t ₃ ,
f ₁₎ specified, the used channel number measuring section 7 transmission station 1 ₁
And find that the receiving station 1 ₂ are not used, respectively, respectively also send and receive any channel in time slot t _3. As a result, the call control manager 8 sets the empty channel (t ₃ ,
f ₁ ) is selected as the assigned channel for the call (1 → 2).

Next, the call control management section 8 sends the time slot t3 and the transmission number 1
And reception number 2. The number-of-assignable-calls reduction number measuring unit 21 uses the channel management table 5 to calculate the number of assignable calls when it is assumed that a new call (1 → 2) has been assigned to an empty channel (t ₃ , f ₁ ). The number of decrease is measured and notified to the call control management unit 8.

Here, a description will be given of the measurement by the allocatable call number reduction number measuring section 21 when the number of slave stations is 5, for example, with reference to FIG. As described above, when the number of slave stations is 5, there are a total of 4 × 5 = 20 kinds of calls. This is shown in FIG. 6 (a), where calls (1 → 2), (1 → 3),
, (5 → 4).

In the time slot t ₃ , as shown in FIG. 36A, the channel (t ₃ , f ₂ ) is used for the call (2 → 3), and the channel (t ₃ , f _M ) is used for the call (4 → Used in 1). Since the number of allowable transmit and receive channels within a single time slot by each slave station 1 ₁ to 1 _L is set to 1 channel, time slot t ₃ the slave station 1 ₂ and 1 _4, and a call to the transmitting station to the slave station 1 ₁ and 1 ₃ call was received station is impossible assignment call, an empty channel (t _3, f ₁₎
Can not be used. Therefore, the time slot t
_{At 3} , the new call (1 →→) is sent to the empty channel (t ₃ , f ₁ ).
FIG. 6 shows the number of calls that can be assigned before assignment 2).
As shown in FIG.

The empty channel (t ₃ , f ₁ ) in FIG.
The Assuming assigned a new call (1 → 2), in order to empty channel is eliminated in the time slot t _3, it becomes impossible assignment any call, assignable call is eliminated in the time slot t _3. That is, a new call (1 → 2) is set in FIG.
The number of calls that can be allocated is 0 when it is assumed that the call is allocated to the empty channel (t ₃ , f ₁ ) of 6 (a).

Accordingly, the assignable call number decrease number measuring section 21
Is that when the new call (1 → 2) is allocated to the empty channel (t ₃ , f ₁ ) in the time slot t ₃ , the number of calls that can be allocated is reduced by 8-0 = 8. And notifies the call control manager 8 of the numeral 8.

Next, the call control management section 8 designates the time slot t _N to the time slot free channel search section 6. The call control manager 8 determines that the time slot t _N is also an allocatable time slot based on the search result of the empty channel in time slot search section 6 and selects it.

Next, the call control manager 8 designates the time slot t _N , the transmitting station number 1 and the receiving station number 2 to the assignable call number reduction number measuring section 21. In time slot t _N , since it is already used for call (4 → 3), FIG.
Call was received station calls and slave station 1 ₃ in which the transmitting station the slave station 1 _4, as shown in (a) becomes impossible allocation call.

Therefore, in the time slot t _N , the number of allocatable calls before allocating a new call (1 → 2) to an empty channel is 13, as shown in FIG. 7A.

FIG. 36 (a)Empty channel (t _N , F ₁ )
ToAssuming a new call (1 → 2) has been assigned,FIG.
Slave station 1 in (a)₁And the slave station 1 with a transmitting station_TwoReceiving
As shown in FIG. 7 (b), a call to be a bureau cannot be assigned.
No, time slot t_NNumber of calls that can be assigned to
Reduced to 8.

Therefore, the assignable call number decrease number measuring section 21
Finds that the decrease in the number of calls that can be allocated is 13-8 = 5 when assuming that a new call (1 → 2) is allocated to an empty channel in time slot t _N , and changes the number 5 to The call control management unit 8 is notified.

The call control manager 8 selects the time slot t _N with the smallest number of calls that can be allocated and allocates an empty channel (t _N , f ₁ ) in the time slot t _N to the new call (1).
→ Select the channel to be assigned to 2).

Since the required number of channels for a new call (1 → 2) is one, the call control manager 8 completes the selection of an empty channel, and as shown in FIG. Channel (t _N , f ₁ ) is assigned to a new call (1 → 2). In this way, it is possible to select an empty channel (t _N , f ₁ ) that has not been selected in the conventional first and second channel allocation methods.

Further, in the allocation state shown in FIG. 36 (c), even if a call (3 → 4) with a required number of channels of 4 occurs, all of the required number of channels from the 4 time slots are required. Can be selected, and the loss rate of a high-speed call can be significantly reduced.

Here, a traffic simulation is performed under the conditions of the table shown in FIG. 8, and the call volume-loss rate characteristics of the high-speed call between the second embodiment and the first and second channel allocation systems of the conventional system are shown. 9 and 10.

FIG. 9 shows a case where the number of slave stations = 32, and FIG.
0 is the case where the number of slave stations = 4. In FIGS. 9 and 10, the total equivalent bandwidth traffic is the total value of the traffic at low-speed call conversion of each slave station. The solid line indicates the characteristic of the second embodiment, the broken line indicates the characteristic of the first conventional channel assignment method, and the dashed line indicates the characteristic of the second conventional channel assignment method.

FIG. 9 shows that when the number of slave stations is 32, the call loss rate of the second conventional channel allocation method is smaller than that of the first conventional channel allocation method. It can be seen that the call loss rate can be made smaller than in the conventional second channel allocation method.

From FIG. 10, when the number of slave stations = 4, the call loss rate according to the second conventional channel allocation scheme is lower than the first first conventional channel allocation scheme.
It is larger than loss probability due to channel allocation scheme,
This is opposite to the case where the number of slave stations is 32. Further, even when the number of slave stations is 4, the call loss rate according to the second embodiment is smaller than the call loss rates according to the first and second channel allocation methods of the related art. Therefore, in the second embodiment, it is possible to realize a reduction in the call blocking rate without depending on the parameter of the number of child stations.

In the second embodiment, as described above, the number of calls that can be allocated at the time when a new call occurs and the allocation is possible under the assumption that the new call is allocated to an empty channel in the allocatable time slot. The number of calls that can be allocated is reduced by assigning a new call to an allocatable time slot. By sequentially selecting and allocating a new call to an empty channel in the selected allocable time slot, priority is given to a time slot that minimizes the number of calls that cannot be allocated by allocating a new call. Selection can reduce the probability of the next potential call being lost, and significantly reduce the loss rate of high-speed calls. It can be.

In the second embodiment, a time slot is first selected and an empty channel in the time slot is selected as in the first conventional channel allocation method. Similar effects can be obtained by selecting a carrier and then selecting an empty channel in the carrier as in the allocation method.

Embodiment 3 FIG. In the second embodiment, the decrease in the number of calls that can be assigned when a new call is assigned is measured, and the measurement is performed for all types of calls to determine whether assignment is possible. Searching is conceivable. When applied to a time division multiple access system using a plurality of carriers having a relatively large number of slave stations, the number of searches becomes enormous.

For example, in the case of a time division multiple access system using a plurality of carriers composed of 100 slave stations,
The number of calls to be searched is (1 → 2), (1 → 3),.
0 → 99), which results in a total of 99 × 100, which leads to an increase in search time and an increase in the time required for the allocation process.

Therefore, in the third embodiment, the number of channels used, the number of transmitting stations, and the number of receiving stations in a time slot are used to focus on the decrease in the number of calls that can be allocated when it is assumed that a new call is allocated. Calculated by the following calculation.

FIG. 11 is a connection matrix composed of a transmitting station number and a receiving station number in a time division multiple access system using a plurality of carriers with the number of slave stations = 5, for example. In FIG. 11, in the connection matrix, an element marked with “○” indicates an assignment state in which one channel is used by a transmitting station corresponding to the row and a receiving station corresponding to the column, and “−” indicates an assigned state. The elements described represent an impossible combination of the transmitting station and the receiving station (when the transmitting station number and the receiving station number are the same), and the elements marked with diagonal lines indicate the unassignable combination of the transmitting station and the receiving station ( represents a call) in the case of a receiving station a call or slave station 1 ₃ in the case where the slave station 1 ₄ and transmitting station.

FIG. 11 shows that the channel management table is shown in FIG.
This is an example in which attention is paid to the time slot t _N in the allocation state of (a). In the time slot t _N , the number of used channels = 1 and only one call (4 → 3) is used. “○” is written at the position of 4 rows and 3 columns of the connection matrix. In the assignment state of FIG. 11, the number of calls that can be assigned is equal to the number of blank elements (combinations of assignable transmitting and receiving stations) that are not marked with “-” in the connection matrix. There are a total of 16 blank elements including the elements marked with “-”. {(Number of slave stations)-(number of channels used)} ² = (5-1) ² = 16

Among them, the elements marked with “-” represent calls that cannot be made, and must be removed. The total number of elements marked with "-" is 5 equal to the number of slave stations, and among the elements shaded with diagonal lines (combinations of transmitting and receiving stations that cannot be allocated), "-" is marked. The number of elements
Since the number of slave stations during communication (the number of slave stations performing transmission or reception) is two, the number of elements marked with “-” in the white elements is (slave station). Number) − (number of communication substations) = 5-2 = 3.

The number of calls that can be assigned is obtained by excluding Equation 3 from the number 16 of white elements including the element in which “−” is obtained. That is, in the allocation state of FIG. 11, the number of calls that can be allocated is 16-3 = 13, which matches the number shown in FIG. 7A described above. If there is no empty channel in the time slot of interest, the number of calls that can be allocated is zero.

The above calculations are summarized in the following equation (1). When an empty channel exists: Number of calls that can be allocated = {(number of child stations)-(number of used channels)} ² -{(number of child stations)-(number of communicating child stations)} When there is no empty channel : Number of allocatable calls = 0 (1)

The decrease in the number of calls that can be allocated when it is assumed that a new call has been allocated is based on the assumption that a new call has been allocated from the value calculated based on Equation 1 above before the new call was allocated. It can be obtained by subtracting the value calculated based on Equation 1 above in the state.

In the third embodiment, as described above,
By calculating the number of assignable calls assuming that a new call has been assigned using the total number of channels used in the time slot of interest, the transmitting station number and the receiving station number , all types of calls are obtained. It is not necessary to search for whether or not assignment is possible, and the assignment process can be performed in a short time.

Embodiment 4 FIG. In the second embodiment, a new call is assigned to a time slot in the order of decreasing number of assignable calls from the time slot having the smallest decrease in the number of assignable calls, but by assigning a new call,
A time slot in which all channels are used, that is, a time slot in which the number of empty channels is 1 and an empty channel disappears when a new call is allocated is a time slot that is difficult to be allocated to a new call. .

Because, as can be seen from the example of FIG. 6 described above, when it is assumed that a new call is assigned to a time slot having only one empty channel, no empty channel is used in that time slot. This is because all the calls that can be assigned become unassignable, and the number of assignable calls decreases greatly.

Further, in the second embodiment, when there are a plurality of time slots having two or more empty channels, the empty channel is more than the empty time slot among the plurality of time slots. There is a tendency to select fewer timeslots and assign an empty channel in that timeslot to a new call.

For example, when the channel management table is in the allocation state shown in FIG. 12, when a new call (1 → 2) having a required number of channels occurs, the time slot that can be allocated has the number of empty channels. a time slot t ₁ is 2, the number of empty channels is time slot t ₂ is 3.

When the decrease in the number of assignable calls when the new call (1 → 2) is assigned to the time slot t ₁ is calculated using the above equation 1, the new call (1 → 2)
Number of calls that can be assigned in the state before the assignment of
2) ^2- (5-4) = 8, and the number of calls that can be allocated under the assumption that a new call (1 → 2) has been allocated = (5
-3) ^2- (5-5) = 4, and therefore the new call (1
→ 2) a time slot t number of reduction in the number of allocatable call, assuming that the assigned ₁ = 8-4 = 4.

Further, when the number of assignable calls is reduced when it is assumed that the new call (1 → 2) is assigned to the time slot t ₂ , the reduced number of calls can be obtained before the new call (1 → 2) is assigned. Number of allocatable calls = (5-1) ² − (5
-2) = 13, and the number of calls that can be allocated under the assumption that a new call (1 → 2) has been allocated = (5-2) ² −
(5-4) = 8, and therefore, the number of allocatable calls decreases when it is assumed that a new call (1 → 2) is allocated = 13−8 = 5, and it is assumed that the call is allocated to the time slot t _1. Bigger than when you did.

[0132] Therefore, the number of empty channels are often empty number of channels than the time slot t ₂ is less time slot t ₁
Is selected, and a new call (1 → 2) is allocated to an empty channel in the time slot t ₁ .

As described above, in the second embodiment, it is difficult to allocate an empty channel in a time slot having one empty channel, and when there are a plurality of time slots having a plurality of empty channels, the There is a tendency to select a time slot with a small number of empty channels and to assign an empty channel in that time slot to a new call.

Therefore, in the fourth embodiment, among the allocatable time slots having a plurality of vacant channels, the time slot having the smallest number of vacant channels is selected in order, and
If an empty channel in the selected allocatable time slot is allocated to a new call, and if the number of empty channels required for the new call cannot be allocated, the vacant required channel is allocated to one empty channel. Select from the available time slots and assign to the empty channel in the selected allocatable time slot.

FIG. 13 is a block diagram showing a configuration of a channel allocating device in a control station for realizing the channel allocating method according to the fourth embodiment of the present invention. In FIG.
Reference numerals 6, 7, and 8 are the same as those in FIG. 31 of the conventional method, and are respectively a channel management table as a channel management unit, an empty channel search unit in a time slot as an empty channel search unit, and a used channel number measurement unit as a used channel number measurement unit. And a call control management unit as a call control management means.
Reference numeral 1 denotes an empty channel number measuring unit as an empty channel number measuring unit for measuring the number of empty channels in a time slot designated by the call control management unit 8.

Next, a channel assignment method according to the fourth embodiment will be described with reference to the flowchart in FIG. Assuming that a new call occurs from the transmitting station 1 _i to the receiving station 1 _j ,
First, in step v1, the call control management unit 8 to select and specify the time slot t ₁ as an assignment candidate time slot t _a in the time slot idle channel search unit 6.

Then, in step v2, the time slot empty channel searching section 6 uses the channel management table to find an empty channel in the time slot t _{1 and} to use any channel in the time slot t ₁ as a transmitting station. 1
_It is determined whether _i and the receiving station 1 _j are not using for transmission and reception, respectively.

At that time, the call control management section 8 firstly sends the time slot t ₁ to the time slot free channel search section 6.
Is specified. The time slot empty channel search unit 6 searches for an empty channel in the time slot t ₁ using the channel management table. As a result, when there is an empty channel in time slot t ₁ ,
The call control manager 8 specifies the time slot t ₁ , the transmitting station number i, and the receiving station number j to the used channel number measuring section 7.

As a result, the used channel number measuring unit 7
The total number of transmission channels by the transmitting station 1 _i and the total number of receiving channels by the receiving station 1 _j are measured using the channel management table 5.

Note that, as described above, each of the slave stations ₁₁ to 1
_{Since the} number of allowed transmission / reception channels of _L is one, in step v2, the number-of-used-channels measuring unit 7 checks the presence / absence of transmission of the transmitting station 1 _i and the presence / absence of the receiving station 1 _j . As a result, it is determined that the transmitting station 1 _i does not use any channel in the time slot t ₁ for transmission, and that the receiving station 1 _j does not use any channel in the time slot t ₁ for reception. In this case, the process proceeds to step v3.

Next, at step v ₃ , the call control management section 8 selects the time slot t ₁ as an allocatable time slot, and specifies the time slot t ₁ to the number-of-free-channels measuring section 11.

Next, in step v4 , an empty channel
The number-of-files measuring unit 11 measures the number of empty channels in the time slot t ₁ and notifies the call control managing unit 8 of the number.

Then, the process returns to step v2 via steps v5 and v9, and returns to time slots t ₂ , t ₃ ,.
Steps v2 to v5 and v9 are similarly repeated in the order of _N , and the number of empty channels in the allocatable time slot is measured, and this is notified to the call control management unit 8.

In step v5, it is determined whether or not all the time slots have been searched. If it is determined that the search has been made, the process proceeds to step v6.

At step v6, the call control manager 8
Selects an empty channel in an allocatable time slot having the smallest number of vacant channels from among allocatable time slots having a plurality of empty channels.

Next, at step v7, the call control management section 8 determines whether or not the required number of channels for the new call has been selected. If the required number of channels is 1, the process proceeds to step v8, where the previously selected channel is selected. An empty channel in an allocatable time slot in which the number of empty channels is the smallest among a plurality of time slots is assigned as a use channel of a new call, and a channel management table corresponding to a channel to which a new call is assigned is assigned. The transmitting station number i and the receiving station number j are set at the element positions, and the operation is terminated.

[0147] In the above step v2, if there is no empty channel in the time slot t ₁ or a transmission station 1 _i
If has already used time slot t ₁ for transmission or if receiving station 1 _j has already used time slot t ₁ for reception, the process returns to step v2 via steps v5 and v9, and thereafter , Allocation candidate time slot t
time slot t _1, t ₃ as _a, ..., choose t _N, the time slot t ₁ the above transmission station 1 _i and the receiving station 1 _j until it finds a time slot not used for transmission and reception, respectively The same process is repeated.

If the required number of channels of the new call is a plurality k, the call control manager 8 proceeds from step v7 to step v13 via step v10, and proceeds to step v13 where the number of available channels is the next smallest. And selects an empty channel from the above and returns to step v7.

Then, in step v7, if the call control manager 8 determines that the required number k of empty channels have been selected, the process proceeds to step v8, where each of the selected empty channels is assigned to a new call, and the operation ends. I do.

In step v7, the call control manager 8 determines that the selection of empty channels for the required number of channels k has not been completed. Further, in step v10, the call control manager 8 If it is determined that has been searched, the process proceeds to step v11.

At step v11, the call control manager 8
Selects the number of empty channels in the allocatable time slot in which the number of empty channels is 1, which is insufficient for the required number of channels k.

Next, in step v12, the call control manager 8 determines whether or not the number of empty channels equal to the required number k of channels has been selected. Each empty channel is assigned, and the operation ends.

If it is determined in step v12 that the number of empty channels equal to the number k of required channels has not been selected, it means that there are some k required channels to which no empty channel has been allocated. , End the operation. This case is called a call loss.

Here, a traffic simulation is performed based on the conditions in the table shown in FIG. 8 , and the traffic volume-loss rate characteristics of the high-speed call between the fourth embodiment and the first and second channel allocation systems of the conventional system. Are shown in FIG. 15 and FIG.

FIG. 15 shows the case where the number of slave stations = 32, and FIG. 16 shows the case where the number of slave stations = 4. 15 and 16, the solid line indicates the characteristic of the fourth embodiment, the broken line indicates the characteristic of the first channel allocation method of the conventional method, and the dashed line indicates the characteristic of the second channel allocation method of the conventional method.

From FIG. 15, it can be seen that the fourth embodiment can reduce the call loss rate as compared with the first and second channel allocation methods of the conventional method. From FIG. 16, in the first and second channel allocation methods of the conventional method, the call blocking rate characteristics are reversed between the case where the number of slave stations = 4 and the case where the number of slave stations = 32, but in the fourth embodiment, Therefore, a small blocking loss rate can be obtained without depending on the number of slave stations.

In the fourth embodiment, as described above, among the allocatable time slots having a plurality of vacant channels, the allocable time slots having the plurality of vacant channels selected are selected in order from the one having the smallest number of vacant channels. When the empty channels in the slot are allocated to the new call and the required number of channels for the new call cannot be allocated to the allocatable time slots having the plurality of empty channels, the empty channels for the new call are vacated. By allocating to the empty channel of the allocatable time slot having one channel, the number of empty channels among the time slots having a plurality of empty channels is minimized by selecting the time slot having one empty channel as much as possible. Only the number of empty channels is measured because time slots with few It is possible to reduce the blocking probability of high-speed call by a simple process.

In the fourth embodiment, a time slot is first selected and an empty channel in the time slot is selected as in the first conventional channel allocation method. Similar effects can be obtained by first selecting a carrier and selecting an empty channel in the carrier as in the channel assignment method.

Embodiment 5 FIG. FIG. 17 is a block diagram showing the configuration of a fifth embodiment of the control station of the channel assignment system according to the present invention. In the figure, a channel management table 5, a time slot free channel search unit 6, a used channel number measuring unit 7, and a call control management unit 8 are the same as the components in the control station in the conventional system. 20
B is assignable call number measuring unit, if assigned the occurrence and vacant channels specified a new call was, in its allocated state, then each assignable channels to all calls that may be occurring The number is counted and notified to the call control management unit 8. Reference numeral 12 denotes a traffic parameter measurement unit which measures the traffic volume between the slave stations, and 13 denotes a weighted assignable call number generation unit, and an assignable call number measurement unit 20.
The number of assignable channels measured by B is weighted based on the traffic volume measured by the traffic parameter measuring unit 12.

FIG. 18 is a flow chart for explaining the operation related to the channel assignment of the control station shown in FIG. The fifth embodiment will be described below with reference to FIGS. First, the traffic parameter measuring unit 12 monitors a channel assignment request from each slave station, and constantly measures the traffic volume between the stations. Here, the transmitting station 1 _i to the receiving station 1
When a new call is originated to _j, in step y1, call control and management unit 8, first, as an assignment candidate time slot t _a, select the time slot t _1, that specifies a time slot in the free channel search unit 5 .

Next, in step y2, the time slot free channel searching section 6 searches the free channel at t ₁ using the channel management table 5. That is, within time slot t ₁ , any channel
_It is determined whether _i is not used for transmission or the receiving station 1 _j is not used for reception.

[0162] Then, in step y3, the result of step y2, there is an empty channel in the t _1, when the transmission station 1 _i is Izu used to transmit, receive station 1 _j is not used for reception, call control management unit 8 selects t ₁ as assignable time slots, then the above allocatable time slots t ₁ on allocatable call number measuring unit 20B, to specify the transmission station number i and the reception station number j.

[0163] Then, in step y4, allocatable call number measuring unit 20B, by using the channel management table 5, tentatively assigned to the new call to the available channel in the time slot t _1, in this assignment state, then occurs For all possible calls, the number of _assignable channels e _ij is measured and _reported to the call control manager 8.

Next, in step y5, the call control management section 8 sends the traffic parameter measurement section 12
The transmitting station number i of all the next possible calls;
Indicate the receiving station number j. The traffic parameter measuring unit 12 calculates the ratio p _{ij of} the calls (i → j) corresponding to the designated transmitting station number i and receiving station number j to the calls (i → j).
On the basis of the measured traffic data between the stations, and notifies the call control management unit 8 of this. The call control management unit 8 calculates the number of assignable channels e _ij measured by the allocatable call number measuring unit 20B and the call occurrence ratio p _ij measured by the traffic parameter measuring unit 12 by using the number of assignable calls. It is specified to the generation unit 13. The weightable assignable call number generator 13 weights the assignable channel number e _ij by the call occurrence ratio p _ij and notifies the call control manager 8 (that is, generates p _ij e _ij ).

Next, in step y6, the call control manager 8 sums the total number E = チ ャ ネ ル p _ij e _ij (all i) of the weighted assignable channels generated by the weighted assignable call number generator 13. , J). Then, through the step y7, y11, repeat steps Y2～y6, processing time slot t ₂ of more than t _1, t _3, ..., by performing the same applies to t _N, the call control manager 8 Knows, for each allocatable time slot, the sum E of the weighted allocatable channels of each call in the state where a new call is allocated to an empty channel in the time slot.

In step y8, the call control manager 8 selects the time slot t _b having the largest total number E of weighted assignable channels, and assigns an empty channel in the time slot to a new call. . Then, through steps y9, y12, and y13, in step y10, when the required number of channels of the new call is k, the total number E of the weighted assignable channels is k in order from the largest time slot to the largest time slot. Number of time slots are selected, and an empty channel in each time slot is assigned to a new call. If k time slots cannot be selected, a call loss occurs.

The above-described channel allocation method according to the fifth embodiment will be specifically described with reference to an example of a channel management table shown in FIG. Now, it is assumed that the communication traffic from the station 1 to the station 2 is large, and the rate of occurrence of calls (1 → 2) is large. In the conventional channel assignment method,
In the allocation state shown in FIG. 22A, the channel position (t ₂ , f ₁ ) is set for a new call (3 → 2) as shown in FIG. 22B.
Is assigned, and the number of channels that can be assigned to calls (1 → 2) having a high occurrence rate becomes zero.

Now, when the communication traffic volume from the station 1 to the station 2 is, for example, 50% of the total traffic volume, that is,
Consider a case where the ratio of occurrence of calls (1 → 2) accounts for 50%. First, the traffic parameter measuring unit 12 monitors the channel allocation request from each slave station and constantly measures the traffic volume between the stations, so that the rate of occurrence of calls (1 → 2) is 50%. I know that. Therefore, traffic parameter measurement unit 12 holds a value of 0.5 as p _12. p ₁₂ = 0.5 (1) Calls other than calls (1 → 2) (X → Y), where X ≠ 1, Y
≠ 2) is 11 stations in total when the number of stations is 4 stations, and the total rate of occurrence of those calls is the remaining 50%.
The rate at which one call is generated is (50/11)%.

The traffic parameter measuring unit 12 calculates p _XY
(However, X ≠ 1, Y ≠ 2) holds a value of 0.5 / 11. There are traffic bias as described above, in the allocation state and channel management table is shown in FIG. 22 (a), the call number of the required channel 1 channel to the receiving station 1 ₂ from the transmission station 1 ₃ (3 → When 2) occurs, the call control management unit 8 sets the time slot free channel search unit 6
Specifies the time slot t ₁ . The in-time slot free channel search unit 6 finds a free channel in the channel (t ₁ , f _M ) by using the channel management table. Next, the call control management unit 8 sets the time slot t ₁ , the transmitting station number 1, the receiving station number 2
Is specified.

[0170] Using channel counting unit 7 finds that the reception station 1 ₂ from the channel management table 5 is used already received at t _1. Therefore, the call control manager 8 sets t
_It is determined that an empty channel in ₁ cannot be selected. Then, when the same processing for the time slot t _2, time slot t ₂ the transmission station 1 ₃ is not transmitted, and,
Free channel (t ₂ from the receiving station 1 ₂ also not received,
The time slot t ₂ where f ₁ ) is present is selected as the allocatable time slot.

The call control manager 8 indicates the time slot t ₂ , the transmitting station number 3 and the receiving station number 2 to the assignable call number measuring section 20B. The allocatable call number measuring unit 20B includes:
A new call (3 → 2) is created using the channel management table 5.
As shown in FIG. 22 (b), tentatively assigning to an empty channel (t ₂ , f ₁ ) in the time slot t ₂ , and in this assignment state, it can be assigned to all calls that may occur next. The number of channels e _ij was measured and FIG.
3 is created, and the call control management unit 8 is notified of the number of channels e _ij that can be allocated to each call.

Next, the call control management unit 8 instructs the traffic parameter measurement unit 12 the transmission station numbers i and the reception station numbers j of all the calls that may occur next. The traffic parameter measuring unit 12 determines the designated transmitting station number i
For the call (i → j) corresponding to the receiving station number j, the call occurrence rate p _ij is obtained based on the measured traffic data between the stations, and is notified to the call control management unit 8. In the case of this example, as shown in Expressions 1 and 2, p ₁₂ = 0.5,
Since p _XY = 0.5 / 11 (where X ≠ 1, Y ≠ 2), the traffic parameter measuring unit 12 creates a matrix indicating the call occurrence ratio as shown in FIG. Notify 8.

Next, the call control management section 8 assigns the weight of the _assignable channel number e _ij measured by the assignable call number measuring section 20 B and the call occurrence ratio p _ij measured by the traffic parameter measuring section 12 to a weight. It is designated to the number-of-assignable calls generation unit 13. Weight assignable call number generation unit 13
_{Calculates the} number of _assignable channels p _ij e _ij, which is weighted, and notifies the call control manager 8 of the number. FIG. 20A is a matrix showing the number of _assignable channels p _ij e _ij obtained by the assignable call number generator 13.

The call control manager 8 calculates the sum E of the number of channels p _ij e _{ij that} can be weighted and assigned as follows. In this case, By performing the same processing as the above processing for the next time slot t ₂ , the weightable assignable call number generation unit 1
3 generates the number of _assignable channels p _ij e _ij weighted as shown in FIG.

The call control manager 8 obtains the sum E of the number p _ij e _ij of _assignable channels by weighting as follows. E = ΣΣp _ij e _ij (all i, j) = 0.5 + 6 × 0.5 / 11 + 3 × 1/11 = 23/22 (4) Through the above processing, the call control management unit 8 determines that the time slot that can be assigned is t ₂ and t _N , and the value of the sum E of the number of channels that can be weighted and assigned is E = 1 when a new call is assigned an empty channel in the time slot t ₂ .
4/22, and when allocating an empty channel in the time slot t _N to a new call, it is known that E = 23/22.

[0176] The call control management unit 8, the largest time slot value of the weighted assignable channel number of the sum E, i.e., by selecting t _N vacant channels in t _N (t
_N , f ₂ ) is selected as the channel to be assigned to the new call. Since the required number of channels for a new call is one,
At this point, the selection of the empty channel is completed, and FIG.
As shown in ( ₂ ), the empty channel (t _N , f ₂ ) is assigned to a new call (3 →
Assigned to 2). As described above, according to the channel assignment method of the fifth embodiment, the unused channels (t _N ,
f ₂ ) and the channel management table 5 is in the state of FIG. 22 ( c ), even if a call (1 → 2) having a high rate of occurrence occurs, the assignment to the call (1 → 2) is made. Since the number of possible channels e _ij is not 0, an empty channel can be allocated to the call (1 → 2).

FIG. 21 is a diagram comparing the call loss rate characteristics of the fifth embodiment with the call loss rate characteristics of the conventional channel assignment method by traffic simulation. Note that the parameters shown in FIG. 24 are used in the above simulation. From FIG. 21, it can be seen that even when there is a bias in the traffic volume between the stations, the present invention can suppress the increase in the call blocking rate of the station where the traffic is concentrated.

Embodiment 6 FIG. In the sixth embodiment, a coefficient for weighting the number of channels e _XY that can be allocated to a call (X → Y) is calculated by the transmitting station by X instead of the occurrence probability p _XY of the call (X → Y).
And the sum of the occurrence probabilities of calls for which the receiving station is Y. That is, for example, the weighting coefficient p ₁₂ ′ for the call (1 → 2) is calculated by the following equation, where L is the number of stations. p ₁₂ ′ = p ₁₂ + p ₁₃ + p ₁₄ +... + p _1L + p ₃₂ + p ₄₂ + p ₅₂ +... + p _{L2 In the} sixth embodiment, when the probability of occurrence of a certain call is extremely small compared to the probability of occurrence of another call, This is effective when the weighting factor of a call is reduced and the call loss rate of the call is significantly increased as compared with other calls.

For example, as shown in FIG. 26A, when the probability of occurrence of a call (3 → 4) is 0.01 and the probability of occurrence of other calls is 0.09, only the call (3 → 4) is weighted. The coefficient is extremely small, 1/9 of the weighting coefficient of other calls, and the call (3 →
Only in the case of 4), the call blocking rate increases remarkably. In such a case, the weighting according to the sixth embodiment is performed, thereby obtaining
As shown in FIG. 6 (b), the weighting coefficient of the call (3 → 4) does not become extremely small, and the remarkable increase in the call blocking rate of only the call (3 → 4) is avoided.

Embodiment 7 FIG. In the seventh embodiment, a weighting coefficient obtained based on the traffic of various calls is used instead of the weighting coefficient obtained based on the occurrence probability of each call type in the fifth and sixth embodiments. That is, since the probability p _ij and Koryou a _ij call is proportional, traffic intensity a _ij
Example 5 using the weighting coefficients obtained based on
The same effects as in the sixth embodiment can be obtained. FIG. 27 is a block diagram showing the configuration of a seventh embodiment of the control station of the channel assignment system according to the present invention. Instead of the traffic parameter measuring unit 12 for measuring the occurrence probability of various calls, a traffic measuring unit 14 is provided. The traffic measuring unit 14 is connected to the channel management table 5 and measures the traffic of each call. Here, the traffic of each call can be easily estimated by monitoring the information of the channel management table 5, that is, the connection state of the line, and measuring the number of simultaneous connections.

Embodiment 8 FIG. FIG. 28 is a block diagram showing a configuration of the eighth embodiment of the control station of the channel assignment system according to the present invention. The difference from FIG. 17 is that the traffic parameter measurement unit 12 in FIG. 17 is replaced with a weighting coefficient storage table 15 in FIG. That is, in the fifth embodiment, the value measured by the traffic parameter measuring unit 12 is used as a value for weighting the number of _assignable channels e _ij .

On the other hand, in the channel assignment method according to the eighth embodiment, a preset value is stored in the weighting coefficient storage table 15 and the number of assignable channels e
_ij is weighted by the held value. Since the number of assignable channels is weighted in the same manner as in the fifth embodiment, the call loss rate of a call transmitted and received by a station where traffic is concentrated is increased. The increase can be kept small. The eighth embodiment is effective when the traffic volume of each station is expected to be small and it is not necessary to measure the traffic parameters. Since the traffic parameters do not need to be measured, the processing relating to the channel assignment is simplified. There is an advantage that you can.

Embodiment 9 FIG. FIG. 29 is a block diagram showing a ninth embodiment of the control station of the channel assignment system according to the present invention. The difference from FIG. 17 is that the traffic parameter measurement unit 12 in FIG. 17 is replaced by a weighting coefficient storage table 15 in FIG. 29, and the difference from FIG. 28 is that a weighting coefficient input unit 16 is present. That is, the eighth embodiment has an advantage that processing related to channel assignment can be simplified by using a preset weighting coefficient without measuring a traffic parameter. In the configuration No. 9, there is an advantage that the weighting coefficient can be inputted from the outside at any time, the processing relating to the channel assignment is simplified without measuring the traffic parameters, and the fluctuation of the traffic volume can be dealt with.

[0184]

As described above, according to the first aspect of the present invention, when a new call is generated by the allocation pattern extracting means based on the use state of a plurality of channels managed by the channel managing means. By extracting all possible allocation patterns for a new call and measuring the total number of calls that can be allocated to all the extracted allocation patterns by the allocatable call number measuring means, An allocation pattern having the largest measured total number of allocatable calls can be selected and allocated to a new call according to the allocation pattern, and a low-speed call having a required number of channels of 1 and a plurality of high-speed calls having a required number of channels can be selected. It is possible to obtain a channel assignment method capable of suppressing an increase in the blocking rate of a high-speed call in a multi-traffic operation in which the traffic is mixed.

According to the second aspect of the present invention, the number of assignable calls can be reduced by the number-of-assignable-calls measuring means based on the use state of a plurality of channels managed by the channel management means, and the new call can be assigned. The number of allocatable calls in the vacant channel in the time slot and the number of allocable calls in a state where the vacant channel in the allocable time slot is allocated to the new call are measured, and the new call is The decrease in the number of allocatable calls caused by allocating to the allocatable timeslots can be measured, and the call management control means assigns the allocatable timeslots to the decrease in the number of allocatable calls. It is possible to select in ascending order and to allocate an empty channel in the selected allocatable time slot to the new call. In heterogeneous traffic operational Yaneru number number of required channels and 1 low speed call and a plurality of fast calls coexist, it is possible to call loss probability of the high speed call obtain channel allocation method can with suppressed from increasing.

Further, according to the third aspect of the present invention, in the channel allocation method according to the second aspect, the decrease in the number of assignable calls is measured by the assignable number of calls. It can be calculated based on the number of channels used in the slot and the number of slave stations using the channels in the allocatable time slot, and search whether all call types can be allocated or not. The assignment process can be performed in a short time, and the blocking rate of a high-speed call can be reduced.

According to the fourth aspect of the present invention,
The number of vacant channels in the allocatable time slot is measured by the vacant channel number measuring means based on the use state of a plurality of channels managed by the channel managing means when a new call is generated. Based on the measurement result of the measuring means, among the allocatable time slots having a plurality of empty channels, the slots are selected in order from the one having the smallest number of empty channels, and the empty slots in the allocatable time slots having the selected empty channels are selected. Channels can be assigned to new calls. If the number of empty channels equal to the number of required channels cannot be allocated to the new call, the number of empty channels is set to 1 by the number of insufficient channels.
Can be assigned an empty channel in an allocatable timeslot. As described above, it is possible to obtain a channel assignment method that can reduce the blocking rate of a high-speed call by a simple process of measuring the number of idle channels.

According to the fifth aspect of the present invention, in a state where the available channel in the allocatable time slot is allocated to a new call by the allocatable call number measuring means, all the possible next occurrences of the allocatable channel are generated. In addition to measuring the number of channels that can be assigned to each call, the traffic parameter measuring means monitors the channel assignment request from each slave station to measure the traffic volume between the stations, and generates a weightable assignable number of calls. Means for weighting the measured number of assignable channels based on the measured traffic amount, based on the rate of occurrence of various calls, The number of assignable channels is weighted by the weight assignable call number generating means, and then the assignable channels are assigned. Obtains the sum of the channel number, select a time slot in order the assignment number of possible channels in total is large, it is possible to allocate a free channel in the time slot to the new call. As described above, it is possible to obtain a channel allocation scheme that can suppress an increase in the call blocking rate of a station where traffic is concentrated even when there is a bias in the traffic volume between slave stations.

According to the sixth aspect of the present invention, in the weight assignable call number generating means of the channel assignment method according to the fifth aspect, the call weighting factor for weighting the number of assignable channels of the call is determined. , Determined as the sum of the occurrence ratio of calls of the same transmitting station and the same receiving station of the call,
Weighting can be performed using this weighting factor, and when the probability of occurrence of a certain call is extremely small compared to the probability of occurrence of another call, it is possible to suppress the call loss rate of that call from increasing significantly compared to other calls. A possible channel assignment scheme can be obtained.

According to the invention of claim 7, in a state where the allocable call number measuring means allocates the free channel in the allocatable time slot searched by the free channel in time slot searching means to the new call. The number of channels that can be allocated to all the calls that may occur next is measured, and the call volume measurement unit is connected to a channel management table managed by the channel management unit, and the call count of each call is The amount is measured and weighted by the weight assignable call number generating means using a weighting coefficient determined based on the measured call volume of each of the above-mentioned calls, thereby generating the above-mentioned various measured calls. Based on the ratio, the number of channels that can be allocated to a call that may occur next is determined by the weighted allocatable call generation method. Each weighted obtains the sum of the number of allocatable channels from, select the time slot in order the assignment number of possible channels in total is larger by,
An empty channel in the time slot can be assigned to a new call. As described above, it is possible to obtain a channel allocation scheme that can suppress an increase in the call blocking rate of a station where traffic is concentrated even when there is a bias in the traffic volume between slave stations.

According to the eighth aspect of the present invention, in a state where the allocable call number measuring means allocates the vacant channel in the allocable time slot searched by the vacant channel in time slot searching means to a new call. , While measuring the number of channels that can be allocated to all the calls that may occur next, storing a preset value in a weighting coefficient storage table, more be weighted using the weighting coefficients obtained from the weighting coefficient storage table, the number of allocatable channels for the next call that may occur, are weighted respectively by the weighting allocatable call number generation means From the total number of channels that can be allocated, and the total number of channels that can be allocated is large. To select the time slots may be assigned a free channel in the time slot to the new call. As described above, it is possible to obtain a channel assignment system that can simplify the channel assignment process and suppress an increase in the call blocking rate of a station where traffic is concentrated, when the traffic volume is expected and the measurement is not required.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control station according to a first embodiment of the channel allocation method of the present invention.

FIG. 2 is a flowchart illustrating an outline of the operation in FIG. 1;

FIG. 3 is a diagram showing the number of _assignable channels e _ij used for explaining the operation of FIG. 1;

FIG. 4 is a block diagram showing a configuration of a control station according to a second embodiment of the channel assignment system of the present invention;

FIG. 5 is a flowchart illustrating the operation of FIG. 4;

FIG. 6 is a diagram showing the number of calls that can be allocated for use in explaining the operation of FIG. 4;

FIG. 7 is a diagram showing the number of calls that can be allocated for use in explaining the operation of FIG. 4;

[8] FIG 9 is a table showing the conditions used to determine the blocking probability characteristic of FIG.

FIG. 9 is a call loss rate characteristic diagram of Embodiment 2 of the channel assignment system of the present invention. (When the number of slave stations = 32)

FIG. 10 is a call loss rate characteristic diagram of Embodiment 2 of the channel assignment system of the present invention. (When the number of slave stations = 4)

FIG. 11 is a diagram illustrating a third embodiment of the control station using the channel assignment method according to the present invention;

FIG. 12 is a diagram showing an example of a channel management table for explaining the operation of the fourth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a fourth embodiment of the control station of the channel assignment system according to the present invention.

FIG. 14 is a flowchart illustrating the operation of the fourth embodiment of the present invention.

FIG. 15 is a call loss rate characteristic diagram of Embodiment 4 of the channel assignment system of the present invention. (When the number of slave stations = 32)

FIG. 16 is a diagram showing a fourth embodiment of the channel assignment system according to the present invention;
It is a call loss rate characteristic diagram . (When the number of slave stations = 4)

FIG. 17 is a configuration block diagram showing Embodiment 5 of the control station using the channel assignment system according to the present invention.

FIG. 18 is a flowchart illustrating the operation of FIG.

FIG. 19 is an occurrence rate p of each call used for explaining the operation in FIG. 17;
_It is a figure showing _ij .

20 is a diagram illustrating the number of channels p _ij e _ij that can be weighted and used for the description of the operation in FIG. 17;

FIG. 21 is a call loss rate characteristic diagram of Embodiment 5 of the channel assignment system of the present invention.

FIG. 22 is a diagram showing a channel management table used for explaining the operation in FIG. 17;

FIG. 23 is a diagram showing the number of channels e _ij that can be allocated and used for explaining the operation of FIG. 17;

FIG. 24 is a table showing the conditions used to determine the blocking probability characteristic of FIG.

FIG. 25 is a diagram showing a traffic model in which the traffic volume between stations is biased.

FIG. 26 is a diagram showing a channel assignment system according to a sixth embodiment of the present invention;
Occurrence ratio p _{ij of} each call used for explanation of operation and weighting coefficient
It is a diagram showing a p _ij '.

FIG. 27 is a configuration block diagram showing a seventh embodiment of the control station of the channel assignment system according to the present invention.

FIG. 28 is a configuration block diagram showing Embodiment 8 of the control station of the channel assignment system according to the present invention.

FIG. 29 is a block diagram showing a configuration of a ninth embodiment of the control station of the channel assignment system according to the present invention.

FIG. 30 is a configuration diagram showing a multicarrier TDMA satellite communication system.

FIG. 31 is a block diagram showing a configuration of a control station using a conventional channel assignment method.

FIG. 32 is a flowchart illustrating the operation of FIG. 31.

FIG. 33 is a channel management table used for explaining the operation of the conventional channel allocation method shown in FIGS. 31 and 34 ;

FIG. 34 is a block diagram showing a configuration of a control station using another conventional channel assignment method.

FIG. 35 is a flowchart illustrating the operation of FIG. 34.

FIG. 36 is a channel management table used for explaining the operation of the channel assignment system of the present invention in FIGS. 1 and 4 ;

[Explanation of symbols]

1 ₁ , 1 ₂ ,..., 1 _L slave station 2 control station 3 satellite 4 data burst 5 channel management table 6 empty channel search section in time slot 7 used channel measuring section 8 call control management section 9 empty channel search section in carrier DESCRIPTION OF SYMBOLS 11 Available channel number measurement part 12 Traffic parameter measurement part 13 Weighted assignable call number generation part 14 Traffic volume measurement part 15 Weighting coefficient storage table 16 Weighting coefficient input part 19 Assignment pattern extraction part 20 Assignable call number measurement part 21 Assignable Number of calls decrease counting section

Claims (8)

(57) [Claims] 1. A plurality of slave stations for transmitting and receiving bursts including information data and communicating with each other by using a plurality of channels obtained by time-sharing a plurality of carriers into a plurality of time slots; In a time-division multiple access system using a plurality of carriers, which manages the use state and allocates a new call newly generated from among the plurality of slave stations to a free channel in an allocatable time slot. A channel management means for managing a use state of the plurality of channels, wherein the control station uses the new call in a time slot of the plurality of time slots when a new call is generated; Used channel number measuring means for measuring the total number of transmission channels and the total number of reception channels used by the receiving station of the new call in the one time slot; An empty channel searching means for searching for an empty channel in one time slot; and a new call at the time when the new call is generated, based on a use state of the plurality of channels managed by the channel managing means. Allocation pattern extracting means for extracting all the allocation patterns, allocatable call number measuring means for measuring the total number of calls that can be allocated to all the extracted allocation patterns, A call control management means for selecting an allocation pattern having the largest total number of calls and allocating a new call according to the allocation pattern. 2. A plurality of slave stations for transmitting and receiving bursts including information data and communicating with each other by using a plurality of channels obtained by time-sharing a plurality of carriers into a plurality of time slots; In a time-division multiple access system using a plurality of carriers, which manages the use state and allocates a new call newly generated from among the plurality of slave stations to a free channel in an allocatable time slot. A channel management means for managing a use state of the plurality of channels, wherein the control station uses the new call in a time slot of the plurality of time slots when a new call is generated; Used channel number measuring means for measuring the total number of transmission channels and the total number of reception channels used by the receiving station of the new call in the one time slot; A vacant channel searching means for searching for a vacant channel in one time slot; and a vacant channel in an allocatable time slot when a new call is generated based on the use state of the plurality of channels managed by the channel management means. The number of calls that can be assigned to the channel and the number of calls that can be assigned under the assumption that a new call has been assigned to an empty channel within the assignable time slot are measured, and the new call is assigned to the assignable time slot. Means for measuring the number of decrease in the number of allocatable calls resulting from the above, and a means for measuring the number of decrease in the number of allocatable calls; Call management control means for allocating the new call to an empty channel in the allocatable time slot. Channel allocation scheme that. 3. The number-of-assignable-calls decrease number measuring means uses the number of channels used in the assignable time slot and the number of channels in the assignable time slot to determine the decrease number of the assignable call number. 3. The channel assignment method according to claim 2, wherein the calculation is performed based on the number of assigned slave stations. 4. A plurality of slave stations for transmitting and receiving bursts including information data and communicating with each other by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots; In a time-division multiple access system using a plurality of carriers, which manages the use state and allocates a new call newly generated from among the plurality of slave stations to a free channel in an allocatable time slot. A channel management means for managing a use state of the plurality of channels, wherein the control station uses the new call in a time slot of the plurality of time slots when a new call is generated; Used channel number measuring means for measuring the total number of transmission channels and the total number of reception channels used by the receiving station of the new call in the one time slot; A vacant channel searching means for searching for a vacant channel in one time slot, and a vacant channel in a time slot which can be assigned based on the use state of the plurality of channels managed by the channel managing means when a new call is generated. Based on the measurement result of the empty channel number measuring means, and from the assignable time slots having a plurality of empty channels, in order from the one with the smallest empty channel number. Allocating an empty channel in an allocatable time slot having a plurality of selected empty channels to a new call, and not being able to allocate the required number of channels of the new call to the allocatable time slot having a plurality of empty channels. And assignable time slots in which the number of vacant channels for the new call is one and the number of vacant channels is one. Channel assignment scheme, characterized in that a call control management means for allocating empty channel of bets. 5. A plurality of slave stations for transmitting and receiving bursts including information data and communicating with each other by using a plurality of channels obtained by time-dividing a plurality of carriers into a plurality of time slots; In a time-division multiple access system using a plurality of carriers, which manages the use state and allocates a new call newly generated from among the plurality of slave stations to a free channel in an allocatable time slot. A channel management means for managing a use state of the plurality of channels, wherein the control station uses the new call in a time slot of the plurality of time slots when a new call is generated; Used channel number measuring means for measuring the total number of transmission channels and the total number of reception channels used by the receiving station of the new call in the one time slot; Based on the use state of the plurality of channels managed by the channel management means, a time slot free channel search means for searching for a time slot in which there is an available free channel using the used channel number measurement means; In a state where a new call is allocated to an available channel in an allocatable time slot searched by the available channel search means, the number of channels that can be allocated to all calls that may occur next is measured. Assignable call number measuring means; traffic parameter measuring means for monitoring a channel assignment request from each slave station to measure the traffic volume between each station; and assignable channels measured by the assignable call number measuring means. Traffic volume measured by the above traffic parameter measuring means Based on the weighted allocatable call number generating means for weighting the number of allocatable channels for the call the next is likely to occur, assignable number of channels from the weighted respectively by the weighting allocatable call number generation means And a call control management means for selecting a time slot in descending order of the total number of assignable channels, and allocating an empty channel in the time slot to a new call. 6. A weighting factor for a call for weighting the number of channels to which a call can be assigned is obtained as the sum of the occurrence ratios of calls of the same transmitting station and the same receiving station of the call, and weighting is performed by using the weighting factor. 6. The channel allocation method according to claim 5, further comprising an allocatable call number generation unit. 7. A plurality of slave stations for transmitting and receiving bursts including information data and communicating with each other by using a plurality of channels obtained by time-sharing a plurality of carriers into a plurality of time slots; In a time-division multiple access system using a plurality of carriers, which manages the use state and allocates a new call newly generated from among the plurality of slave stations to a free channel in an allocatable time slot. A channel management means for managing a use state of the plurality of channels, wherein the control station uses the new call in a time slot of the plurality of time slots when a new call is generated; Used channel number measuring means for measuring the total number of transmission channels and the total number of reception channels used by the receiving station of the new call in the one time slot; Based on the use state of the plurality of channels managed by the channel management means, a time slot free channel search means for searching for a time slot in which there is an available free channel using the used channel number measurement means; In a state where a new call is allocated to an available channel in an allocatable time slot searched by the available channel search means, the number of channels that can be allocated to all calls that may occur next is measured. Assignable call number measuring means, a call volume measuring means connected to a channel management table managed by the channel managing means for measuring the traffic volume of each call, and a call volume measuring means for each call measured by the traffic volume measuring means. using a weighting coefficient determined on the basis of the traffic intensity, the weighting allocatable call number generating means for weighting The number of assignable channels for the call the next is likely to occur, the total sum of weighted assignable number of channels respectively by the weighting allocatable call number generation means, the sum of the assignment number of possible channels Call control management means for selecting a time slot in descending order and assigning a free channel in the time slot to a new call. 8. A plurality of slave stations for transmitting and receiving bursts including information data and communicating with each other by using a plurality of channels obtained by time-sharing a plurality of carriers into a plurality of time slots; In a time-division multiple access system using a plurality of carriers, which manages the use state and allocates a new call newly generated from among the plurality of slave stations to a free channel in an allocatable time slot. A channel management means for managing a use state of the plurality of channels, wherein the control station uses the new call in a time slot of the plurality of time slots when a new call is generated; Used channel number measuring means for measuring the total number of transmission channels and the total number of reception channels used by the receiving station of the new call in the one time slot; Based on the use state of the plurality of channels managed by the channel management means, a time slot free channel search means for searching for a time slot in which there is an available free channel using the used channel number measurement means; In a state where a new call is allocated to an available channel in an allocatable time slot searched by the available channel search means, the number of channels that can be allocated to all calls that may occur next is measured. and assignable call number measuring unit, a weighting coefficient storage table for storing a preset value, with a weighting coefficient determined based on the weighting coefficient storage table, a weighting allocatable call number generating means for weighting, following the number of assignable channels for the call that may occur in the above The total number of allocatable channels is obtained after weighting by the assignable call number generating means, and time slots are selected in descending order of the total number of allocatable channels. And a call control management means for allocating a channel.