JPH01314031A - System for assigning frequency to radio control line - Google Patents

Abstract

PURPOSE:To set a voice line even if the active control line frequency is disable of use by switching the frequency of the control line from the active frequency into the standby frequency automatically if a disturbing radio wave is detected while the active frequency is assigned to the radio control line and in operation. CONSTITUTION:If a disturbing radio wave detector (DET) 26 detects a disturbing radio wave while a radio base station 2 is in operation through the control line of the active frequency band, the DET 26 sends a detection signal 5 to an exchange 1 and a changeover switch (SW) 22 applies switching connection to an antenna 21 from a transmitter-receiver (TRA) 22 of the active frequency band to the transmitter-receiver (TRS) 23 of the standby frequency band as shown in broken lines in figure. Then the frequency handles by a transmitter- receiver (TRS) 23 of the standby frequency band is used for the radio control line (Lc) 4 to carry the control signal subject to transmission reception control by a control line controller (CTLS) 25. Thus, even if the active radio control line is disabled of use, the voice channel is set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio control line frequency allocation method in a mobile communication system.

[Conventional technology]

Conventionally, this type of radio control line frequency allocation method allocates a plurality of frequencies exclusively to each radio control line in a fixed manner within a mobile communication system.

FIG. 3 is a diagram showing radio frequency bands in an example of a conventional radio control line frequency allocation system. In FIG. 3, a control line band 31 is allocated to a control line 35 and a control line 36. The voice line band 32 is allocated from the voice line 37 to the voice line 38. Control line 35
The frequency of the control line 36 is fixed in the system, and the voice lines 37 to 38 are set for each call according to the connection sequence of the control line 35 or the control line 36.

[Problem to be solved by the invention]

In the conventional radio control line frequency allocation method described above, the frequency of the radio control line is fixed, so if jamming radio waves overlap with this, the radio control line becomes unusable within the reach of the jamming radio waves. This has the disadvantage that it is not possible to set up a voice communication path.

[Means to solve the problem]

The radio control line frequency allocation system of the present invention is a mobile communication system consisting of a plurality of radio base stations connected to an exchange and a plurality of mobile stations connected to each radio base station via a radio control line. In the system, each of the radio base stations includes a detecting means for detecting jamming radio waves, an allocating means for allocating a spare frequency to the radio control line when the detecting means detects a jamming radio wave, and an allocation means for assigning a frequency of the radio control line to the active radio control line. and switching means for switching from the frequency of 1 to the spare frequency.

〔Example〕

Next, the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram showing an embodiment of the radio control line frequency allocation method of the present invention. For simplicity, the case where there is one radio base station and one mobile device connected to it is illustrated. be.

In FIG. 1, the mobile communication system of this embodiment includes a wireless base station 2 connected to an exchange 1, and a mobile station 3 connected to the wireless base station 2 via a wireless control line (hereinafter referred to as Lc) 4. Become. The wireless base station 2 includes an antenna 21 and a transmitter/receiver (hereinafter referred to as TRA) 22 in the current frequency band, which is connected to the antenna 21 via a changeover switch (hereinafter referred to as 5W) 22. Reserve frequency band transmitter/receiver (hereinafter referred to as TR3) 23 and TRA22゜T
A control line control device (CTLA24, CTLS25) each connected to R823, and a jamming wave detection device (hereinafter DTE) that detects jamming waves received by the antenna 21.
)26.

Next, the operation of this embodiment will be explained.

In a normal state, the wireless base station 2 operates on the control line of the current frequency band, and uses 5W22 (shown with a solid line) to
RA22 and CTLA24 are operating, and TR323 and CTLS25 in the reserve frequency band are inactive. Antenna 21.5W22. TRA22. CTLA
When the DET 26 detects a jamming signal via the DE
T26 transmits the detection signal 5 to the exchange 1, and in response to the switching signal 6 sent from the exchange 1, 5W22 switches and connects the antenna 21 from the TRA 22 to the TR 323 as shown by the broken line. Therefore, after that, the reserved frequency band TR323,C
TLS25 operates, and TRA22. of the current frequency band is activated. CT
Since LA24 stops its operation, Lc4 uses the frequency handled by TR523 in the reserve frequency band to transmit CTLS25.
A control signal that controls transmission and reception is carried.

FIG. 2 is a diagram showing an example of the radio frequency band in FIG. 1, with (a) and (b) showing the states before and after the control line is switched from the working band to the protection band, respectively.

As shown in FIG. 2(a), normally the current control line band 41 is allocated to LC and LC2, and the voice line band 42 is allocated to voice lines Lv1 to LVa. Further, the spare control line band 43 is allocated on a frequency band including LVa.

Lol and LC2 carry connection signals for setting LV, ~LVn for each call.If either LC or LC2, or both, becomes unusable due to jamming radio waves, the number of lines of Lc that becomes unusable The same number of control lines (one or two lines) are automatically allocated to the spare control line band 43. In this case, the number of usable Lv lines is reduced by the number of control lines (1 or 2 lines) automatically allocated to the spare control line band 43.

Next, in FIG. 2(b), the current control line band 41 is intercepted by interference radio waves (hereinafter referred to as DIS). 2 is included, and the voice line band 42 is allocated to Lv1 to Lv1. Further, the spare control line band 43 is allocated to LCI'. The control line band 41 is a control line t of two frequencies.
,c,, has the bandwidth to which LC2 can be allocated, but DET26 (shown in FIG. 1) detects DIS. It is assumed that only 2 can now be used. At this time, L01' is automatically allocated to the spare control line band 43 and used. Therefore, in the overall system band, LC2 is used for the active control line band 41, and LC2 is used for the backup control line band 4.
3 is assigned to Lcl', the number of control lines becomes two, and the LCI in the case of Fig. 2 (a), LC2
is the same number.

〔Effect of the invention〕

As explained above, the present invention allocates a working frequency to a radio control line and automatically switches the frequency of the control line from the working to the standby when jamming radio waves are detected during operation. Since the voice line can be set up even if the voice line becomes unavailable, it is effective in maintaining the system's ability to handle the traffic.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of the radio control line frequency allocation method of the present invention, Fig. 2 is a diagram showing an example of the radio frequency band in Fig. 1, and Fig. 3 is a diagram showing a conventional radio control line frequency allocation method. FIG. 3 is a diagram showing radio frequency bands in an example of the method. DESCRIPTION OF SYMBOLS 1... Exchange, 2... Radio base station, 3... Mobile device, 4... Radio control line (Lc), 5... Detection signal,
6... Switching signal, 21... Antenna, 22... Changeover switch (SW), 22.23... Transmitter/receiver (TR
A. TR3), 24.25...Control line controller (CTL)
A, CTLS), 26... Interfering radio wave detection device (DET
), 41... Current control line band, 42... Voice line band, 43... Reserve control line band.

Claims (1)

[Claims] In a mobile communication system consisting of a plurality of radio base stations connected to an exchange and a plurality of mobile devices connected to each radio base station via a radio control line, each of the radio base stations transmits interference radio waves. a detection means for detecting interference, an allocation means for allocating a spare frequency to the radio control line when the detection means detects a jamming wave, and a switching means for switching the frequency of the radio control line from the current frequency to the spare frequency. A wireless control line frequency allocation method comprising: