JPH09233535A - Mobile radio station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a revision command for an individual control channel (CCH) by allowing a mobile station to select any of the CCHs based on the result of combination between a group code corresponding to the CCH received from a base station and a stored group code number of its own station so as to distribute the traffic to the CCH. SOLUTION: A base radio station BS stores number (n) of CCHs assigned to its own station to a control channel (CCH) memory Sp and stores number (ntp) of groups to a group number memory Spntp. A group controller TST stores the group code atp of the CCH derived from the numbers (n) and (ntp) to group code memories Sp1-n of relating channel controllers KST1-n. A mobile radio station MS selects any of the CCHs based on the result of combination between a code atp received in a receiver E and stored in a memory SpMa and a group number K stored in a memory Spk by a combination switching circuit V. Thus, the traffic is distributed to plural CCHs of a cellular form and even when the configuration of the CCHs is subject to change, no individual revision command to the CCHs is required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio station in a radio transmission system in which traffic is distributed over a plurality of control channels.

[0002]

2. Description of the Related Art German Patent Application Publication No. 2733503
In a radio communication system (radio transmission system) known from U.S. Pat. ) And some traffic channels. Thus, a mobile radio station (base radio station) in a radio zone with a large number of mobile telephone subscribers (mobile radio stations) needs to be provided with one transmitter / receiver for several control channels. . To simplify the configuration of the transmission and reception separation filters, the transmission and reception frequency band is divided into an upper band and a lower band. Each of the mobile radio stations divided into at least two groups uses either the upper band or the lower band of the transmission / reception frequency band. The division of the transmission / reception frequency band into two bands is selected so that both groups of mobile radio stations have a common band. The control channel is located at least in this common band.

[0003] One mobile radio station of the first group selects, for example, one control channel for setting a line. Because of this, the mobile radio station has a good signal-to-noise ratio (S / N)
Is scanned for control channels assigned to the group. S of selected control channel
If / N decreases due to radio propagation interference or for some other reason, the mobile radio station, upon receiving the predetermined control channel code, changes the control channel assigned to another group, eg, the second group. It can also be used. The allocation of control channels to such other groups is only taken over in radio areas with a small number of mobile radio stations.

When several control channels are used in one radio area, the traffic volume corresponding to mobile radio stations installed and registered in this radio area is distributed to several control channels in this radio area. To be done. This known wireless transmission system (DE-AS273350)
In 3), the mobile radio stations are divided into a plurality of groups to reduce the price of the transmission / reception separation filter. However, there is no description of a control method that considers a traffic state, particularly, a method of distributing a traffic amount over various control channels. For example, if four control channels are assigned to one radio zone, and four
If there are only two groups in a group radio area, the traffic volume is only spread over the two control channels assigned to the two groups.

If the number of the control channel of the zone belonging to a certain radio zone, that is, the frequency of the control channel, and thus the channel number of the control channel, changes,
Each mobile station needs to automatically and independently assign the station to a newly set control channel. For example, when assigning a new control channel to the radio area, the existing and new control channels are temporarily overloaded by a large number of individual transfers of the mobile radio station for a short period of time. It is necessary to take some measures so that it is not overwhelmed.

A problem underlying the present invention is to provide a mobile radio station in a system that distributes the amount of traffic on multiple control channels in a radio area. In the event that the control channel fails and changes its configuration, it must not require a separate change order for the new control channel.

[0007]

OBJECTS AND SUMMARY OF THE INVENTION The object of the present invention is at least 2
Base station (B) having two control channels (CCH)
S) In a system for distributing traffic on individual control channels in a cellular radio transmission system including S), a mobile radio station is connected to a channel associated with the control channel from the base radio station via the control channel. Receiving means for receiving each group code (atp), storage means for storing a group code number (K) for identifying the mobile radio station, each received channel group code (atp) and the stored group Selecting means for combining a code number (K) with a predetermined combination criterion, and selecting one of the control channels as a control channel assigned to the mobile radio station based on a result of the combination. It is to solve the above-mentioned problem by comprising.

According to the present invention, it is possible to distribute the traffic volume almost uniformly over various control channels in the radio zone of the radio transmission system.

[0009] Some of the many mobile radio stations are in radio contact with the base radio station.

[0010] A known wireless transmission system (DE-AS27)
In the case of 33503), when a radio connection is made from a known radio station to the mobile radio station, the mobile radio station needs to be called on all control channels of the radio area. According to the present invention, it is possible to prevent all such control channels from being unnecessarily overloaded. At the same time, the number of transfers to the overload control channel of the mobile radio station can be reduced. The amount of traffic on various control channels at any one time can be known by measuring traffic at the base station. The variable number of groups in the known radio transmission system is selected appropriately for both the base radio station and the mobile radio station so that the various groups are distributed as evenly as possible in each radio zone. The number (ntp) of this group indicates how many groups the total number of mobile radio stations located within the radio coverage area of the base radio station is divided. By combining the group code number with the number of groups transmitted over the control channel and the group code, the mobile radio station can allocate itself to the control channel in an unambiguous manner. The control channel group code (atp) indicates which group of mobile radio stations is assigned to use that channel. By changing this group code, the base station can easily control the distribution of the traffic volume over its various control channels. Advantageous variants of the invention are described in the dependent claims.

[0011]

The invention will be described with reference to the drawings.

[0012] The wireless transmission system is configured at a hierarchical level consisting of several levels that are layered together. The lowest of these levels is the radio area (radio zon
e) What is known as. Depending on the height of the antenna mast at the base radio station BS, for a transmitter power of up to 50 watts, the radius of these radio zones can be in the range of 5 to 15 km. Each radio area is covered by one base radio station BS, which can relay conversations from and to the public telephone network via a radio relay device.
Some adjacent wireless areas can be merged into what is known as a paging area. The locations of all mobile radio stations MS are constantly monitored by base stations whose locations are stored in an address book. When the mobile radio station MS changes its paging area, it changes the location information registered in the address book.

If one telephone subscriber of the public telephone network wants to talk to a certain mobile radio station MS, the call is sent to all radio areas of the paging area monitoring the mobile radio station MS at that time. The selected call (call) is transmitted, and the corresponding mobile radio station is registered at that moment.

The transmission and reception frequency bands are, for example, 860
〜960 MHz. The duplex communication interval between the transmit and receive frequency bands can be 45 MHz, and the transmit and receive frequency bands can be subdivided into 25 KHz channel intervals. These channels are used in a duplex operation.

[0015] A number of traffic channels and at least one control channel CCH are allocated to each radio zone of the radio communication system according to the traffic volume. This means that different frequencies (control channels) are used in geographically adjacent radio areas. In order to distinguish between the control channel CCH and the traffic channel, a specific code is given to each of those channels. However, if a control channel is bad, useless or obstructed, any traffic channel can take over the function of that control channel by changing the sign. By doing so, it is possible to eliminate duplication of the control channel CCH required for maintaining reliability.

In a conventional radio transmission system (German Offenlegungsschrift 2 733 503), once a mobile radio station is switched on, the radio station has the best signal-to-noise ratio (S / N). Perform a channel orientation search. When the control channel is acquired, the channel number is stored, and the mobile radio station enters a stationary state. Then, such a mobile radio station constantly monitors the S / N of the control channel. If the S / N of the control channel stored at the time point described above falls below a predetermined value and becomes useless, the mobile radio station scans another control channel in the search mode and compares the S / N. Changes in wireless area can be identified by such S / N comparison, and the mobile wireless station stores the channel number of its corresponding control channel. In a certain radio area, a line to be transmitted or received or a line with a mobile telephone station of a public telephone network or a radio transmission system is established at a predetermined instant via a control channel CCH, a base radio station and a radio relay device. There is a mobile radio station. In the conventional radio transmission system (German Application Publication No. 2733503), the mobile radio station stores the channel number of the control channel having the highest S / N. In this way, the amount of traffic on various control channels in one wireless zone can change according to the traffic condition.

In the above radio communication system, all the mobile radio stations located in the area are divided into a group TP of a fixed number ntp. Each mobile radio station is then permanently and unambiguously assigned to one of these groups TP. For the sake of simplicity, in the following, the mobile radio station MS is a group of 100 T
Assume that it can be divided into P. The group code number K is a part of the identification code mid stored in the mobile radio station MS. The mobile radio station MS can, for example, assign to one of the groups TP based on the least significant two-digit number yz of the identification code mid. At this time, the criterion mtp is the same as the last two digits yz. Therefore, the mobile radio station MS with the identification code 59988 belongs to the group TP = 88. The base station BS is a mobile station MS on each control channel CCH.
To the group code atp. By combining the group code atp with the stored group code number K, the mobile radio station MS can guide clear allocation to the control channel CCH. The group code atp sent from the base radio station BS to the mobile radio station MS is, for example, two parts,
That is, it can be composed of the maximum number ltp and the minimum number ftp. The mobile radio station MS satisfies the condition ftp ≦ mtp ≦ l
Assign self to a control channel CCH that satisfies tp. In the following example, mtp is assumed to be equal to K.

Case 1 At predetermined moments, channel numbers 589, 614 and 76
Three control channels CCH having 5 are allocated to one radio zone. If each control channel CCH carries one third of the traffic volume, the base radio station MS
Traffic volume is evenly distributed within the wireless coverage area. With the group code atp sent on the control channel CCH1 (of channel number cnr = 589), the base radio station BS informs that the minimum number is ftp = 00 and the maximum number is ltp = 32. On the control channel CCH2 (of channel number cnr = 614), the base station BS gives the mobile station MS the minimum number ftp = 3.
3 and the maximum number ltp = 65. Correspondingly, control channel CCH3 (of channel number cnr = 765)
In the above, the smallest number is ftp = 66 and the largest number is ltp
= 99. Group code number K = 88 (identification code 5998)
The mobile radio station MS having 8) has its own control channel C
Assign to CH3. This is because the condition 66 ≦ 88 ≦ 99 is satisfied for this channel. The channel number cnr = 765 of the control channel CCH3 can be stored in the mobile radio station MS. Thanks to this unambiguous assignment, the mobile radio station MS has the control channel CC
It can be paged by the base radio station BS on H3.

When switched on, each mobile radio station MS allocates itself to a radio area control channel CCH. In the next course of the event, the mobile radio station MS continuously checks whether the conditions for this control channel CCH are satisfied. When this condition stops being satisfied, the mobile radio station MS starts searching for the control channel CCH that satisfies the condition instantly. If several control channels CCH satisfy this condition, the mobile radio station MS assigns itself to the control channel with the highest SN ratio or the control channel with the highest field strength, which is a matter of preference. . If the base radio station BS also sends a code for the paging area in addition to the group code atp, a change in the paging area is identified at the mobile radio station MS. When the mobile radio station recognizes only such a change, there is some rerouting via the selected control channel of the new paging area.

As means for controlling the spread of traffic on the control channel, the base station BS can change the maximum number ltp and the minimum number ftp. The unequal spread of the amount of traffic can be measured by measuring the traffic on the control channel CCH by the base radio station BS.
You can check with In this way, when the maximum number ltp and the minimum number ftp change, there is an advantage that no special change command is required in each individual mobile radio station MS. In addition, the traffic on the individual control channel CCH is not required. There is the advantage that the amount of In one radio area, only one page for a particular mobile radio station MS needs to be sent on one control channel CCH. Cover it,
The mobile radio station MS is, in any case, one of the
This is because it is assigned to a specific number of control channels CCH.

Case 2 In this example, it is assumed that the amount of traffic is divided by the following ratio. That is, the control channel CCH1
40% on control channel CCH2 and 20% on control channel CCH3. Thus,
On the control channel CCH1, the minimum number ftp is set to 00, the maximum number ltp is set to 39, the minimum number ftp = 40 and the maximum number ltp = 79 on the control channel CCH2, and the control channel CCH3
The lowest number ftp = 80 and the highest number ltp = 9
If it is 9, the base station BS redistributes the amount of traffic. As a result of the change of the maximum number ltp and the minimum number ftp, the mobile radio stations whose group code numbers K are 33 to 39 change from the control channel CCH2 and allocate themselves to the control channel CCH1. Further, the group code number K is 66
The mobile radio stations MS at ~ 79 assign themselves to the control channel CCH2 (previously it was the control channel CCH3).

Case 3 For example, when the control channel CCH fails, the configuration of the control channel CCH needs to be changed. In this example, the control channel CCH2 fails and the base station BS
Alternatively, it is assumed that the wireless relay apparatus has designated the control channel with the channel number 623 instead. (Before control channel C with channel number cnr = 614
This new control channel CCH2 with channel number cnr = 623 (although it was CH2) has the lowest number ftp =
Control channel CC which has failed by sending 33 to mobile radio station MS with 33 and the maximum number ltp = 65
Take over the function of H2.

Case 4 Here, as in Case 3, control channel CCH2
Is different, except that the base radio station BS or the radio relay device does not nominate any new control channel CCH2 instead. The base station BS sends the minimum number ftp = 00 and the maximum number ltp = 49 on the control channel CCH1 (of channel number cnr = 589). Then, the base radio station BS sends the minimum number ftp = 50 and the maximum number ltp = 99 on the control channel CCH2 (previously the control channel CCH3 but the channel number cnr = 765). Therefore, the amount of traffic depends on the control channels CCH1 and CCH1.
2 evenly distributed. Thus, the mobile radio stations MS, which previously allocated themselves to the control channel CCH2, now allocate themselves in equal amounts to the control channels CCH1 and CCH2.
CH2. In this way, the mobile radio stations MS that have redistributed themselves find themselves on a new channel after the search.

Here, the base station BS uses the 16-bit word as the group code atp to control the two control channels CCH1 and CCH.
It is assumed that the message is sent on CH2. The number of mobile radio stations existing in the area covered by the radio of the radio communication system is divided into 16 groups TP according to the number of groups ntp = 16.

The criterion mtp is calculated by the mobile radio station MS. This is, for example, the remainder when the stored group code number K is divided by the number ntp of the group. Group code number K
= 88 determines that this criterion mtp is equal to eight.

The base station BS controls the control channel CCH1.
And the group code atp = 11111111 0000 0
000 and the group code atp = 0000 0000 1111 1111 on the control channel CCH2. The minimum number ftp and the maximum number ltp of the control channel CCH1 are 0 and 7, respectively (for the control channel CCH2, ftp = 8 and ltp = 15). Therefore, the mobile station MS having the criterion mtp = 8 allocates itself to the control channel CCH2. In this case, the group code a
The first bit of tp is assigned to criterion mtp = 0, the second bit is assigned to criterion mtp = 1, and so on, and the last bit is assigned to criterion mtp = 15. The mobile radio station MS uses the control channel CCH
Has, for example, a logical 1 characteristic state at the bit position of the group code atp assigned to the criterion mtp,
Assign themselves to the control channel CCH. (M
The mobile radio station MS (of tp = 8) assigns itself to the control channel CCH2 for the information described above.

The distribution of the amount of traffic on the various control channels described above can be changed step by step.

FIG. 1 is a block diagram showing a control device of such a system. The base radio station BS has a control channel memory Sp and a group number memory Spntp whose output terminals are respectively connected to the input terminals of the group control device TST, and further has n channels corresponding to the number n of allocated control channels CCH. A control device KST is provided. Each channel control device (for example, KST1) has a group code memory (for example, Sp1), the input terminal of which is connected to the output terminal of the group control device TST, and the output terminal of which is connected to the input terminal of the investigation control device ABS1. I have. The output terminal of the survey control device ABS1 is connected to the input terminal of the transmitter S1.

The mobile radio station MS has a receiver E and a first memory SpMa. The output terminal of the first memory SpMa is connected to the input terminal of the combination switching circuit V.

The mobile radio station MS also has a second memory SpK whose output terminal is connected to another input terminal of the combination switching circuit V.

In the base station BS, a number n equal to the number of control channels CCH allocated to the base station BS is stored in the control channel memory Sp.
The number ntp of the group is stored in pntp. These two numbers n and ntp are supplied to a group controller TST, from which the group code atp for each control channel is derived from which these group codes are associated with the associated channel controller KST.
m (m = 1,..., n) group code memories Spm (m = 1,
.., N).

The group code atp is the inspection control unit ABSm
And supplied to the associated transmitter Sm.

The transmitted group code atp is the mobile radio station MS
Received by the receiver E existing in the first memory SpM
Supplied to a. And the group code at stored here
p is the second memory SpK by the combination switching circuit V
Is combined with the group code number K stored in A control signal for allocating the mobile radio station MS to one of the control channels CCH is obtained at a terminal Em of the combination switching circuit V.

FIG. 2 shows two channel control memories Sp # 1 and S # in each channel controller KSTm of the base station BS.
This shows a modification in which p # 2 is provided. In this case, the minimum number ftp is stored in the first channel control memory Sp # 1, and the maximum number ltp is stored in the second channel control memory Sp # 1.
Stored in p # 2. These two numbers are used to obtain the group code atp, for example, as described above. In this modification, the two memories Sp and Spntp and the group control device TST are unnecessary.

[Brief description of drawings]

1 is a block diagram of a control device including a mobile radio station according to the present invention;

FIG. 2 shows a channel controller for a base station.
It is a block diagram of the modification provided with the memory.

[Explanation of symbols]

 BS ... Base radio station, MS ... Mobile radio station, Sp ... Control channel memory, Spntp ... Group number memory, Spm ... Group code memory, SpMa ... First memory, SpK ... Second memory, Sp # 1, Sp # 2 ... Channel control memory, TST ... Group control device, ABS ... Investigation control device, S ......... Transmitter, E ......... Receiver, V ......... Combination switching circuit, En ... Terminal.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Philip Duplessis France 78141 Verizy Cedex Sul Lattecourt 10 (72) Inventor Alain Talabou France 78141 Verizy Cedec Sul Lattecourt 10

Claims (3)

[Claims] 1. A plurality of base wireless stations form a cellular type wireless area, and a plurality of control channels and traffic channels are allocated to the base wireless stations in each wireless area.
In a mobile radio station used in a cellular radio communication system in which the base radio station communicates with a plurality of mobile radio stations in the radio area via these channels, these base radio stations transmit these via the control channel. Channel group code (a
tp), storage means for storing a group code number (K) for identifying the mobile radio station, each received channel group code (atp) and the stored group code number (at). And K) based on a predetermined combination criterion, and selecting one of the control channels as a control channel assigned to the mobile radio station based on the result of the combination. A mobile radio station, characterized in that: 2. A channel group in which the channel group code (atp) includes a large number (ltp) and a small number (ftp), and the group code number (K) of the selecting means satisfies ftp ≦ K ≦ ltp. The mobile radio station according to claim 1, wherein a control channel corresponding to the code is selected as a control channel assigned to the mobile radio station. 3. The channel group code (atp) includes a binary number sequence consisting of logic "1" and logic "0", and the selecting means determines the group code number (K) in the binary number sequence. A control channel corresponding to a channel group code in which a digit corresponding to a remainder divided by the number (ntp) of a predetermined logic has a predetermined logic is selected as a control channel assigned to the mobile radio station. Range 1st
The mobile radio station described in the item.