JP2689567B2 - Circuit allocation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a channel allocation method, and more particularly to channel allocation for a circuit in which frequency bandwidth or time division method in multiplex wireless communication has a finite frequency bandwidth or allocation time interval. The present invention relates to a suitable line allocation method.

[Conventional technology]

Conventionally, this kind of line allocation method has been described in FIG. 3 and FIG. 4 for explaining the channel allocation of the frequency division method and the time division method, respectively. If there is
Call 1 to the vacant channels ch1 to ch5 on the frequency axis in Fig. 3.
~ Call 12 is sequentially assigned. For example, channels are sequentially assigned in the order of call 2 for ch1, call 3 for ch4, and call 4 for ch5. When the call 1 is ended, call 6 is assigned. Here, the frequency bandwidths Δf of ch1 to ch5 are the same and fixed, and the entire multiplexed band Δf _B is also fixed. When audio signals are connected to ch1 to ch5, the channels are arranged at frequency intervals that do not deteriorate the audio signals. Next, in the case of the time division method, as shown in the explanatory diagram of FIG.
The same time slot Δt is assigned to each of channels 1 to ch5, and the time Δt of the entire multiplexed frame is also fixed. As in the case of frequency division, telephone calls for line connection requests are sequentially assigned to the vacant channels of each time slot.

[Problems to be solved by the invention]

In the above-mentioned conventional line allocation method, the frequency bandwidth Δf and Δf _B or the time intervals Δt and ΔT are finite when the number of channels is increased in order to cope with the increase in communication users. Is taken, or in the case of time division, the transmission speed is slowed down, and the quality of the voice signal itself is significantly deteriorated. That is, practically, there is a drawback that the voice of the other party becomes difficult to hear with the voice signal, and it becomes difficult to know who the other party is.

[Means for solving the problem]

The line allocation system of the present invention is a line allocation system using a time division multiplexing system in which one frame is composed of time slots Δt of a plurality of channels, and at least some of the plurality of channels are at least the above-mentioned channels. After forming a time slot Δt _S divided into less than half of the time slot Δt and assigning one of the calls assigned to the time slot Δt of the plurality of channels to a certain time, the time slot Δt _S Switch to the appropriate channel.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

 FIG. 1 is an explanatory view of one embodiment of the present invention.

In the embodiment of FIG. 1, a call for which a connection request is made is initially a channel having a frequency bandwidth Δf which is a high quality channel.
Calls 2 to 17 are sequentially assigned to 1 to ch3, and after a certain period of time, they are narrower than the frequency bandwidth Δf, which is a low-quality channel, for example, ch4 to ch7 having a frequency bandwidth of Δfs = 1 / 2Δf. The line allocation is changed. For example, ch1 call 3 is ch4 call 3 ', ch2 call 4 is ch6 call 4'
And so on. If you do such line allocation,
In a communication in which high quality communication is required initially after the line connection and low quality may be obtained after a certain period of time, the present embodiment is applied to the band Δf _{B in} which the number of channels that can be multiplexed is the same as that of the conventional example in FIG. Then, it becomes possible to allocate two more channels. Next, the case of the time division method will be described with reference to FIG. ch1
~ Ch3 is for high quality channel, time slot Δ
The same time interval as in the conventional example is assigned to t. ch4 to ch7
Is for a low quality channel and is assigned a time slot Δt _S less than the time slot Δt. The time interval of one multiplexed frame is ΔT as in the conventional example.
That is, with respect to the same ΔT, in this embodiment, it is 2 than in the conventional example.
It is possible to allocate many channels. Second as mentioned above
The time slots Δt for ch1, ch2, and ch3 in the figure are for high-quality channels, and specific numerical values are, for example, audio signal 3.
Since a sampling frequency of 8Khz for 4Khz and a PCM multiplexed signal that transmits 24ch in one frame is generally a code of 1ch 8bits structure, in this case, the quantization step of the voice amplitude is 2 ⁸ = 256 information of steps. Can be generated. That is, the time slot Δt of 1ch is about 5.2 μs (0.65 μs / pulse × 8). However, it is said that 2 ³ = 8, that is, 8 steps is sufficient as the quantization step of the voice amplitude if it can be understood as a word. Therefore, in the present application, the time slots of ch4 to ch7 in FIG. 2 are about 2.6 μs, which is 1/2 of the conventional 5.2 μs as a time slot for low quality, and if the bit configuration of 1 ch is 4 bits, ch1,2 It is possible to allocate channels twice each of 3 and 3. In this way, by adopting the method of shifting the line assignment from the high-quality channel to the low-quality channel after a lapse of a certain period of time, it is possible to effectively use the frequency bandwidth or the time interval and secure a large number of channels. In the case of voice communication, a high-quality call is required to recognize who the other party is immediately after the call starts, but the quality of the sound becomes a little poor after recognizing who the other party is. Does not interfere with the call.

〔The invention's effect〕

As described above, according to the present invention, by providing a channel having a standard call bandwidth and a channel having a narrow call bandwidth, it is possible to realize a line having a larger number of channels multiplexed than before, and to realize a frequency It has a great effect on effective utilization of bandwidth or time-division time bandwidth.

[Brief description of the drawings]

1 and 2 are explanatory views of one embodiment of the present invention, FIG.
FIG. 4 is an explanatory diagram of the frequency division and time division methods of the conventional line allocation method. ch1 to ch7 …… communication channel, Δf …… frequency bandwidth, Δ
f _S ...... Narrow frequency bandwidth, Δf _B …… Frequency band, Δt
…… Time bandwidth, Δt _S …… Narrow time bandwidth, ΔT …… Total frame time.

Claims (1)

(57) [Claims] 1. In a channel allocation method using a time division multiplexing method in which one frame is composed of time slots Δt of a plurality of channels, at least some of the plurality of channels are at least the time slots Δt. Corresponding to the time slot Δt _S after a certain time has elapsed after forming a time slot Δt _S divided into channels of ½ or less of Line allocation method characterized by switching to.