Method and device for transfer of the mobile station from the first to the second channel of the mobile communication system

 

(57) Abstract:

In the mobile communication system is a method and apparatus for switching the mobile station from the first working channel of the base station on the second channel is assumed for the further base station, and in the process of doing mobile station transmission, starting with the first cycle of the transmission on the first channel, the second channel is ready to establish communication with this mobile station, starting from the second cycle. On intended for further work base station has means for determining the interval of the temporary displacement of the transmission cycle, and configured to tune a frequency of the mobile station to determine until the switching time offset of the second cycle relative to the first transmission cycle, and also provides a means for time shifting, allowing you to shift after shift transmission cycle of the mobile station on the designated specified interval relative to the first transmission cycle. The technical result is the creation of a method and device for accelerating the process of switching from one base station to another. 2 C. and 8 C.p. f-crystals, 5 Il.

The invention cash other intended for further work - base station comprising a mobile communication system.

The method also applies to the switching of the mobile station from the first to the second channel of the same base station, which already serves this mobile station. When the mobile station is transmitting at the first stage on the first channel, the second channel is ready to establish communication with this mobile station to operate in transmission mode at the second stage.

The invention relates also to a device for implementing the method.

The prior art.

In a mobile communication system, for example in a cellular mobile radio system, megacheese switching are reduced to a simple translation of the previously established call from one base station of one cell to the base station of another cell, whereas vnutrichasovye switch is simply the transfer of communication from one channel to another part of the same base station.

Vnutrichasovye switch are usually made to change the base station, for example, due to the occurrence of a certain environment within the cell or to redistribute channels and pamestilaas, for example, when the communication quality of the used channel falls below the minimum level, or during the procedure of establishing a call when the mobile station switches from the control channel to the communication channel.

When within or between cells is unsynchronized switching channels or channels, the phase difference between which is not known at the mobile station, this station should personalityrelated on the new channel. The process of such resynchronization takes a substantial period of time, for example, about 200 MS, which leads to the interruption of the speech signal, which cannot be neglected and which could disrupt the ongoing voice communication.

In the patent application WO 9222966 describes a method used in a cellular mobile radiotelephone system for initial setting time coordination of the mobile station.

This method includes the steps of computing the optimal parameter negotiation time, which are then used during the connection with the new working channel of the desired base station; sending the calculated parameter negotiation at the mobile station and the installation of a matching point in time on the system, using mobile stations with two local oscillators (lo). If there are two local oscillators can receive signals on the first channel and at the same time to transmit on a different channel. This fact can be used to reduce the switching time.

Disclosure of the invention

The present invention is the task of creating a method and device for accelerating the process of switching from one base station to another, speed up communication by reducing the time needed to switch from the control channel to the working channel and accelerate the transition from one working channel to another within the scope of the same General base station in order to avoid interruption in the process of switching channels and to avoid surgery resynchronization.

This object is achieved in that in the method according to the present invention, until the switch determines (after configuring the mobile station associated with the desired base station time offset between the first transmission cycle and the second cycle. Then after switching shift the transmission cycle of the mobile station at a given interval is set to a time otnosite provides a means to define the time offset, part intended for the base station and used to configure the mobile station to determine (to toggle) the relative time shift between the first and second transmission cycles, and shift (after the switch) transmission cycle of the mobile station on the value of the specified time interval relative to the first transmission cycle.

Examples of mobile communication systems, which can find application in the present invention can provide a system with frequency division (FDMA) time division (TDMA), code (CDMA) and the so-called DECT system.

One of the advantages of the present invention is to eliminate the need for resynchronization, which reduces the time of calculation and saves computer resources.

Another advantage is improving the quality of voice communication due to the lack of communication in the speech channel.

Brief description of drawings

The invention is further illustrated by examples of its implementation with reference to the accompanying drawings, in which:

Fig. 1 represents a General scheme of the mobile radio system.

Fig 2,a - 2,e - examples of different transmission cycles, which occur when Perna switching taking into consideration the intensity of the signals.

Fig. 4 is a block diagram of the means for time offset and determine the interval time zone offset.

Fig. 5 is an algorithm illustrating a method of accelerating the switch according to the present invention.

Preferred embodiments of the invention

In Fig. 1 schematically shows a mobile radio system that implements the method and the device according to the present invention.

This system contains two base stations BS1 and BS2, which are located in the adjacent cells C1 and C2.

The base station BS1 and BS2 are connected, for example, cables switching center mobile objects MSC or other switching/managing hardware unit, for example a base station controller (BSC) or mobile telephone switching service, which are used in cellular systems.

The switching center SC connected, for example, the cables from the fixed public switched telephone network PSTN is known in this technical field.

Obviously, with the switching center MSC can be linked much more base stations than those shown in the figure.

In Fig. 1 shows one mobile station the stations.

In this example, it is assumed that the mobile station MS communicates with operating in the base station BS1 via digital data exchange channel CH1 and broadcasts, since TO, as shown in Fig. 2,a - 2,e. Here the time indicated by the symbol "Tau". Transmitted by the mobile station information is received by being delayed by the propagation time of radio waves d1 base station BS1 at the time of the transmission cycle T1,as shown in Fig.2,S. the base station BS1 monitors the state of the channel CH1, controlling, for example, signal intensity or the frequency of occurrence of errors.

In Fig. 3 presents graphs of the variation of the intensity of the signal SS received from the base stations BS1 and BS2, depending on the distance between the mobile station MS and the base station BS1.

The mobile station monitors the transmission quality (e.g., signal intensity) on the channel CH1 belonging to the base station BS1, and the quality of the channel CH2, belonging to the base station BS2.

The distance between the mobile station MS and the base station BS1 are indicated by an X. the Curve S1 shows the intensity of the signal received from the base station BS1, and the curve S2, the intensity of signal from bazi is moving in the direction of the base station BS2. The mobile station MS communicates over the channel CH1 with the base station BS1 and moves in the direction of the base station BS2.

In the first position X1 to the intensity of the signal from the base station BS1 identified as S11, and from the base station BS2 as S21. Because at this point the intensity of the signal S11 exceeds the intensity of the signal S21, the communication with the base station BS1 is not interrupted. At the second position X2, the intensity of the signal S12 from the base station BS1 becomes less intensity signal S22 from the base station BS2, resulting in a transition from the base station BS1 to the base station BS2.

The mobile station MS continuously measures the intensity of a signal from the base station, and transmits the results of these measurements on the control channel, such as channel type SACCH system GSM mobile communication system.

These results can also be sent on the control channel to the base station BS1 and BS2 or switching/controlling devices of other types, such as a base station controller (BSC), mobile telephone switching service, etc. used in the technique of cellular communication.

For experts in the field of technology should be apparent that the movable bit errors (BER) instead of measuring the intensity of signals in the same way as was described above.

When the mobile station MS is connected to the channel CH1, she supervises the work of this channel, for example, by measuring the frequency of occurrence of bit errors and/or intensity of the received channel CH1 signal S11.

In addition, can be measured intensity signals and/or frequency of bit errors in some other channels, such as channel CH2, working in the neighboring cell, and can be measured, for example, the intensity of the signal S21 supplied from the base station BS2 in cell C2. The initiating mobile station MS for such measurements performs, for example, the base station BS1.

The results of measuring the characteristics of the channels are compared, for example, on the same base station BS1 or the switching center mobile objects MSC by viewing the values of received signals and/or frequency of occurrence of bit errors (BER) transmitted by the mobile station on the control channel.

If this comparison indicates that communication with the same base station, for example BS1 or another base station BS2 has a higher quality on a different channel than the currently used base station BS1 generates a switch request, direction is assumed for further work, receives the instruction to switch to communication with the mobile station MS on the channel CH2.

In an alternative preferred embodiment, the base station located near the existing station BS1, tune in to the channel CH1, currently used by the mobile station MS, and measure the intensity of the received signal. If the comparison of the measurement results shows a higher quality of communication when working with another base station, the switch is made to work with this base station.

It is shown in Fig. 2,a - 2,e rectangular pulses, means the parcel in the form of packets of pulses in a system with multiple access and time division (TDMA), although they may serve as an illustration and for other types of systems such as frequency division (FDMA), coding (CDMA) and the so-called DECT systems.

The transmission cycle T2, desirable to start the transfer station MS according to the channel CH2, as shown in Fig. 2,b, is shifted to the interval offset T relative to the cycle T0, desirable for transmitting mobile station MS according to the channel CH1, as shown in Fig. 2,a.

The cycle T3, when the base station BS2 receives the signal of the mobile station MS, a detainee at the time of distribution station MS by the base station BS2, being arrested at the time of radiowave propagation d2.

As can be seen in the presented figures, the time interval T between the desired torque signal transmission in the mobile station MS according to the channel CH2 (Fig. 2,b) and the actual time of the transfer station MS according to the channel CH1 (Fig. 2, a) has the same duration as the interval temporal offset between the desired torque receiving base station BS2 (Fig. 2,e) signal of the mobile station MS according to the channel CH2 and the base station BS2 signal of the mobile station MS according to the channel CH1.

In accordance with the present invention, the interval time zone offset T between the base station BS2 signal of the mobile station MS on the channel CH1 after the delay time of radiowave propagation (Fig. 2,d), and desired time of good reception of the base station BS2 signal transmitted by the mobile station MS according to the channel CH2 (Fig. 2,e), is determined at the base station BS2 means for measuring the interval - TODM, adapted to configure the mobile station MS. The tool TODM explained in more detail below in the description of Fig. 4.

Before switching on the mobile station MS data is transmitted on this interval offset T or the example so that the base station BS2 transmits the relevant information to the switching center mobile objects MSC, and that in turn transmits the data to the base station BS1, which finally transmits the data interval bias T mobile station MS. This information can be transmitted on the control channel, for example, type SACCH.

After switching, i.e., when the mobile station MS must be in communication with the base station BS2 station MS sends an instruction instructing to shift the start of the transfer T0 (Fig. 2,a) on defined before this interval offset T to coincide with the cycle T2 (Fig. 2,o) relating to the channel CH2.

To ensure this operation, the mobile station MS is provided with a means for shifting during TSM capable of moving within the cycle time of the transmission of the mobile station MS to a known interval T. the Operation of this device a time offset TSM explained in more detail below in the description of Fig. 4.

Thus, the beginning of the mobile station MS is consistent with the proper initiation of the channel CH2 without performing resynchronization before transmission over the channel CH2.

In Fig. 4 shows in block diagram a tool La time 12 and a device for calculating the temporary settings 14.

On the correlator 10 is supplied to the word synchronization 16 of the mobile station MS from the mobile communication system, in addition, the correlator receives demodulated data from 24 of the mobile station MS.

At the output of the correlator produces trigger pulses 18, which are received by the device 12 measurement time interval, which also served starting synchronization signals 26 corresponding to the synchronization signals intended for the future work of the channel CH2.

The device 12 produces at its output the value of the time interval is 20, indicating the time between trigger pulses synchronized 26 and correlatordata trigger pulses 18. This temporary value 20 is received by device 14 performing time calculations, in particular the spacing of the temporary offset 22, which is removed with the release of this device. This value 22 is identical interval offset T, shown in Fig. 2.

After the base station checks the status of the mobile station, it receives from the communication system synchroscope.

In Fig. 4 shows the means for the temporary shift TSM containing starting the generator 2, which receives the internal signal Sinmun offset 22, it is shown in Fig. 4 and described above

Starting the generator 2 produces at its output a starter pack of trigger pulses 4. At offset 6 position of the trigger pulses on the time axis, i.e. the start of the pulse sequence, moves, allowing you to control the starting stack starting pulses 4. These trigger pulses 4 are used to trigger and synchronize the transmission mode of the mobile station MS.

In this embodiment of the present invention the means for shifting in time TSM is located on the mobile station MS, but in General it can be located in other places, such as base stations or mobile switching center objects MSC.

Means define a time offset TODM is located at the base station BS2, but can also be installed in various locations of the mobile communication systems, such as mobile station MS.

Used in the present description, the terms (the word synchronization, time offset, and so on) are well known to experts in the art and meet the TIA-IS-54.

In Fig. 5 shows an algorithm illustrating a method of accelerating the procedure of switching, according to Nast who ate (see Fig. 1). The algorithm begins with step 46. Next, in step 30 the mobile communication system determines whether switching of the mobile station MS with working with her base station BS1 to the backup base station BS2. Is this definition by measuring signal strength, as indicated by consideration of Fig. 3.

At step 32, the system generates a request to the base station BS2 to check the status of the mobile station MS, which is a well-known procedure. During this test the base station BS2 tuned to the frequency of the mobile station MS and sets the synchronization synchroscope.

At step 34, the base station BS2 may also (optionally) to make the identification of the mobile station MS. Next, the algorithm proceeds to step 36, where the base station BS2 determines at what interval of time should be shifted synchronization of the mobile station MS to align with the new channel, which is already served by the base station BS2. Step 36 is performed by means TODM determine the time offset, as indicated under consideration Fig. 4.

After step 36 is followed by a step 38, in which the base station BS2 sends data on the size of the interval temporal bias in the evaluation of the s GSM system (ground support), which control the operation of several base stations.

At step 40, the base station BS1 introduces the spacing offset in a switching command sent to the mobile station MS.

Then in step 42 the mobile station MS moves to a new operating frequency and prepares your parcel in the form of a pulse packet, shifting it to the specified interval for immediate radiation (the team) without any further measurements. The shift is made in the tool TSM time offset as described above.

At step 44 switches to the mobile station MS from the serving base station BS1 to the backup base station BS2.

The algorithm ends in step 48, which is followed by step 44.

In accordance with the present invention a backup base station BS2 may, controlling radio communication between the mobile station MS and the serving base station BS1, to measure the magnitude of the time interval T, to which the mobile station MS must shift the beginning of the cycle of the radio in order to work in harmony with the intended for further operation of the base station BS2.

The measured interval time zone offset of T includes the difference is wound radio waves, due to different distances from the mobile station to the base stations BS1 and BS2.

The mobile station MS receives the command, which includes an indication of a new channel and measured value of the interval time zone offset.

In addition, this station separately receives the calculated value of the interval time coordination for communication with a new base station on the new channel. Due to such provision of data necessary for the normal operation and synchronization interval time zone offset of the mobile station MS does not require resynchronization before transmission in new mode.

If method according to the present invention is used in a synchronized system, i.e., if the base station BS1 and BS2 have one common synchronization, another advantage of this method is that the measured interval time zone offset is the exact difference between the synchronization of the current communication mode and the estimated after switching. This makes it possible to accurately determine the value of the time correction (based on calculations) for the new mode.

According to the present invention is that a part of such a procedure can be and the switching of the mobile station MS from the control channel to digital work (information) channel of the same base station.

As mentioned previously, such switching is one of the possible types vnutripochechnykh switches. Important here is the fact that when considered with the other types vnutripochechnykh switches do not need to personalisierte mobile station, which can save time.

When such vnutripochechnykh switches in the scope of one base station assumes that the channels are not synchronized and/or have a difference in time starts transmitting, unknown to the mobile station.

The interval time zone offset of T does not necessarily have to survive with very high accuracy. Enough, if due to the establishment of such movement will not occur overlay of signals of different mobile stations and will be provided by the management of the beginning of the transmission cycle of the mobile station in this time window, where you can find synchroscope. For this purpose the spacing offset subjected to quantization.

Through the use of the method and device according to the present invention breaks in the ongoing voice communication during switching so short that they successfully masked the Oia duration of less than 40 msec.

The term "switch" as used in the present description, refers to switching from the first channel of one base station to another channel from the coverage of another base station, and switches from the control channel on the desktop (information) channel when the communication between base and mobile stations, and switching from channel to channel total base station and other possible switches.

It should be borne in mind that used in this description, the terminology has only a descriptive, but not restrictive sense.

1. The method for switching a mobile station (MS), which is part of the mobile communication system, the first channel (CH1) served by the base station (BS1) associated with station MS, the second channel (CH2) served by the base station (BS2), we choose to maintain further communication with a mobile station (MS), and in the process of transmitting the mobile station MS, starting with the first cycle of the transmission on the first channel (CH1), the second channel (CH2) is ready to communicate with a mobile station (MS) for the conduct of its transmission from the second cycle, characterized in that before and after switching of the base station settings after switching to produce the offset of the transmission cycle of the mobile station (MS) in the above-defined time interval relative to the first transmission cycle, moreover, the measured time difference includes a difference of the synchronization settings of the base stations BS1 and BS2, and the difference in the signal delay caused by the propagation of radio waves, due to the different distances from the mobile station to the base stations BS1 and BS 2.

2. The method according to p. 1, characterized in that the mobile station (MS) send data on the magnitude of the time shift, or provide it with the information that allows a station to set the specified set time shift until the switch.

3. The method according to p. 2, characterized in that the mobile station (MS) after switching shift the transmission cycle for a fixed time interval relative to the first transmission cycle.

4. The method according to p. 1, characterized in that as a working base station and intended for further work in the new mode, the base station use the same station, the scope of which determines the interval time offset, and the redistribution of the communication channel within the same cell and in the scope of one base station assumes that the channels are not synchronized and/or have a time difference of times of transmission of the nei is g is subjected to quantization.

6. The device comprising a mobile communication system for switching a mobile station (MS) from the first channel (CH1) operating a base station (BS1) to a second channel associated with the proposed for further work by the base station (BS2), and the mobile station is still transmitting, from the first transmission cycle, on the first channel (CH1) and the second channel (CH2) is ready to establish communication with a mobile station (MS), starting from the second transmission cycle, characterized in that provide a means of determining the time interval offset (TODM), installed at the base station (BS2) with the possibility of tuning the frequency of the mobile station (MS) to determine until the switch relative temporal offset between the first and second moments of the beginning of the transmission cycle, and means for shifting in time (TSM), designed to shift after the moment of switching of the transmission cycle of the mobile station (MS) to a defined time interval relative to the first transmission cycle, while the measured time shift includes both the difference of the synchronization settings of the base stations BS1 and BS2, and the difference in the signal delay caused by the propagation of radio waves, due to the significant difference is the fact, that it is provided with a means for informing the mobile station (MS) on the size of the previously defined time offset or transfer to this station information to install the station (MS) pre-defined interval time zone offset until the switch.

8. The device according to p. 7, characterized in that the means for time shifting (TSM) is installed on the mobile station (MS) with the ability to shift after shift transmission cycle of the mobile station (MS) to a defined interval offset relative to the first transmission cycle.

9. The device according to p. 6, wherein operating the base station and intended for further work in the new mode, the base station has the same base station, which is equipped with means for determining the interval time zone offset, and the redistribution of the communication channel within the same cell and in the scope of one base station assumes that the channels are not synchronized and/or have a time difference of times of transmission unknown to the mobile station.

10. The device according to p. 6, characterized in that it is provided with a means for quantization of the designated interval vremennogo

 

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Mobile phone system // 2118068
The invention relates to a mobile telephone system that provides connectivity with mobile phones between two or more telephone points in a telecommunication system

FIELD: radio communications.

SUBSTANCE: proposed method intended for single-ended radio communications between mobile objects whose routes have common initial center involves radio communications with aid of low-power intermediate transceiving stations equipped with non-directional antennas and dropped from mobile object, these intermediate transceiving drop stations being produced in advance on mentioned mobile objects and destroyed upon completion of radio communications. Proposed radio communication system is characterized in reduced space requirement which enhances its effectiveness in joint functioning of several radio communication systems.

EFFECT: reduced mass and size of transceiver stations, enhanced noise immunity and electromagnetic safety of personnel.

1 cl, 7 dwg, 1 tbl

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