JPH05505925A - Quality check of mobile cellular communication systems - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Quality checking of mobile cellular communication systems Field of invention This invention provides a cell having a channel for transmitting information between a base station and a mobile station. generally relates to communication systems. In particular, the invention relates to signal strength and signal interference. The present invention relates to a method for selecting and allocating traffic channels based on the following.

Background of the invention In a cellular mobile communication system, a mobile station that has established a wireless channel connection , from one cell served by one base station to one cell being served by one base station. It is essential to be able to maintain this established connection when moving to another cell that receives It is a term. Furthermore, if a mobile station that has established a wireless channel connection moves within the same cell, However, when using a channel with a lot of interference, this established connection can be It is particularly desirable to be able to maintain

The process by which a mobile station ensures an established connection while traveling in a cellular communication system is commonly called handoff.

In general, wireless communications require that the radio signal is carrying the desired information or that the signal strength is sufficient. is possible only when the radio signal is strong enough to influence the receiver, It is Noh. Naturally, this minimum strength depends on system characteristics, e.g. modulation scheme, reception It depends on the type of communication device, etc. Connect the established connection between the mobile station and the intended base station. handoff and continue on the intended radio channel. The process includes measuring the parameters of the radio signal at the intended base station and/or mobile station. including The first cellular mobile systems in common use typically analog systems for other forms of analog information. this system transmits analog information between base stations and mobile stations by transmitting analog modulated radio signals. Contains multiple radio channels for transmitting information. Generally, the first cellular mobile communication system The stem has relatively wide cells, making the handoff process in such systems Signal measurements at stations were performed by base stations. North of one such system There is a European (Nordic) mobile telephone system, NMT 450. other known The AMPS mobile communication system in the United States is one of the cellular mobile communication systems currently in use. move A comprehensive description of cellular communication systems is Er1csson Telecom “CMS 88 Cellular Mobile Telephone” published in 1988 by A.B. The use of these communication systems will be found in The rapid growth in demand sometimes makes it difficult to use cells to their maximum capacity. Ru.

In a cellular mobile communication system, when setting up a call or starting a new call A traffic check that does not cause transmission problems when handed over to a traffic channel. It is important to assign channels. Existing systems suffer from poor transmission. The quality of the signal can be improved by blocking the channel, i.e. beyond a predetermined level. traffic channel that fosters interference is prevented. There is. However, the simplicity of this method is such that the All channels with interference signals between the requesting mobile station and the base station Blockades of any intensity reduce the system's call handling capacity. Furthermore , poor transmission when the requesting mobile station's signal is at a relatively low signal level. May cause quality problems.

Summary of the invention The present invention provides a method for dealing with interference that has a lower rate than the signal strength of the requesting mobile station. The shortcomings of the prior art are overcome by selecting a traffic channel that

In the present invention, the signal strength of the mobile station making the request is Measured when requesting a traffic channel between stations. computer is cell Determine if there are available traffic channels for the mobile system. do. If the cellular mobile system has available traffic channels, If not, requests for traffic channels by mobile stations will result in the system being blocked. is denied until it encompasses the specified traffic channel. system is locked down When enclosing a traffic channel, a blocked traffic channel temporarily unblocked, which provides a usable traffic channel. It will be done.

In one embodiment of the invention, a traffic channel is selected and the traffic A level of interference for the channel is determined. The signal strength and traffic of the requesting mobile station A comparison between the disturbance level of the traffic channel and the trough The disturbance level of the dynamic channel is determined to be below a minimum threshold. If The interference level of the traffic channel is determined by the signal strength of the requesting mobile station. selected by the requesting mobile station when less than the lowest threshold. traffic channels are assigned. Selected traffic channel If the disturbance level exceeds a minimum threshold, other traffic channels are selected. selected. This cycle is the minimum threshold from the signal strength of the requesting mobile station. A traffic channel with a disturbance level lower than the Continue until

In a second embodiment of the invention, all available traffic channels are The interference level is measured.

Traffic channels are ordered according to their interference level. make a request The signal strength of the mobile station is compared to the interference level of the traffic channel, At least one traffic channel has a disturbance level below the minimum threshold It is determined whether the The minimum threshold is based on cellular mobile traffic. It can be varied depending on the activity. at least one traffic channel the communication strength of the mobile station making the request minus a minimum threshold. If the level of interference is low, the requesting mobile station has an interference level closest to the signal strength of the moving station minus the minimum threshold , or some other predetermined order, e.g., the lowest threshold, fic channels are assigned. However, all available troughs The mobile station has a minimum threshold value from the signal strength of the requesting mobile station. When the computer has a higher interference level than the Measure the interference level of the traffic channel again and check if the signal strength is determined by the system. Traffic compatible with the signal strength of the mobile station making the request is continuously monitored. Continue this until the search channel is found.

Brief description of the drawing Figure 1 shows a cell containing a mobile switching center, a base station, and a mobile station. This figure shows part of a mobile communication system.

FIG. 2 is a flowchart of a subroutine used by a computer according to an embodiment of the present invention. Shows a low chart.

FIG. 3 is a flowchart of a subroutine used by a computer according to another embodiment of the present invention. Shows a low chart.

Description of the preferred embodiment FIG. 1 shows cells C1-C10 of IO of a cellular mobile communication system.

Typically, the cellular mobile communication system of the present invention is equipped with ten or more cells. death However, for the sake of simplicity, the present invention uses the simplified representation shown in FIG. It is explained as follows.

For each cell Cl-Cl0, a group with the same reference number as the corresponding cell. There is a local station Bl-BIO.

Figure 1 shows a base station located near the center of the cell and equipped with omnidirectional antennas. There is. Thus, cells Cl-Cl0 are schematically represented by hexagons. death However, the base stations of neighboring cells are located near cell boundaries and are well known to those skilled in the art. It is equipped with a directional antenna.

Figure 1 also shows the nine movements that can be made within a cell and from one cell to another. Station Ml-M9 is shown.

In a typical cellular communication system, there are usually nine or more cellular mobile stations. Ru. In fact, there are typically many times more mobile stations than base stations. However, the invention described For this purpose, a reduced number of mobile stations is sufficient.

As shown in Figure 1, mobile switching center ing center) MSC is placed. Mobile Suit shown in Figure 1 The switching center MSC is connected to all ten base stations by cables.

Mobile Switching Center (MSC) is also a fixed public switching telephone Connected to a cable to a fixed network such as a network. all mobils Cable from switching center MSC to base station Bl-BIO and fixed network Cables to the network are not shown.

The mobile switching center MSC1, shown: 'In addition, the mobile switching center MSC1, shown in FIG. Another mobile switch that is cabled to a different base station than the A cutting center can also be placed. Instead of cables, e.g. fixed wireless connections can be used. Other methods such as connecting base stations B1-B10 to a mobile switching center It can also be used to continue. Mobile switching center MSC, base station B l-BIO and mobile station Ml-M9 are all controlled by a computer.

The cellular mobile communication system shown in Figure 1 has multiple radio channels for communication. do. Such systems can be designed for analog or digital information. Although the present invention can be applied to both analog and digital systems, the following The description is based on the assumption that it is an analog system. Some radio channels are control channels. Used for flannel. And each base station Bl-BIO has at least one Grow fgi11 channel. Control channels typically carry call information. Not used for The control channel is used to set up the connection, and to register the move (immediately). The mobile station monitors and controls the mobile station (i.e., the mobile station reports to the ground station to which it belongs). used for

Each cell is always equipped with a signal strength receiver consisting of a receiver and a graphical unit. It will be done. Signal strength receivers typically measure It has the same design as the receiver used. The signal strength of each cell receiver is determined by the period measurements and samples the radio frequencies received from the mobile station. all system frequencies are sampled but assigned to mobile stations in neighboring cells. Only the traffic channel frequencies that are used are involved in node-off. which channel Information about which files should be considered is provided by the MSC during the above-mentioned sampling. Originally received. The measurement results are averaged by the control unit after periodic sampling. Updated. In this way, each cell has to take over the transmission. If necessary, the mobile station currently using the adjacent traffic channel We will know which are the send parameters in. Handoff by cell If requested, the MSC transmits the signal strength measurements from the mobile station to neighboring cells. ask them to send it.

Referring to FIG. 2, a simplified flowchart is shown for M Indicates a subroutine of a computer located either in the SC or in the base station. ing. The computer receives signals from mobile stations requesting access to the base station. Controls the measurement of strength. Signals are pre-existing that require handoff It can represent a cell or a new cell. Requesting access to base station The mobile station's signal strength depends on scheduled changes in the received signal strength of the traffic channel. Adjustments may be necessary for further changes. For example, a control channel used by a mobile station The channel power level determines what the mobile station uses for the traffic channel. The signal strength may differ from the expected signal strength. For example, the mobile station using a control channel with a power level of 3 corresponding to -6 dBW at Is it possible to contact the base station that is there?

Ru. However, the traffic channel of the cell has a power equivalent to -2 dBW. Level 2 is acceptable. As a result, the signal strength of the requesting mobile station is The power increases by 4 dB. In other instances, a mobile station may develop a very high signal strength. Ru. Moving candidate traffic channels after setting up or calling a call Station power adjustment control can reduce the output power of the mobile station, thereby , reduce the received signal strength.

The computer can handle the requesting mobile station in step 103. system trough to determine if there are any traffic channels that mic channel to scan. The available traffic channels are A cellular system that blocks channels with a level of interference that exceeds a predetermined level. some unblocked channel not used by the system, or a predefined Cellular systems that do not block channels with interference levels exceeding the established level This is a channel that is no longer in use. If the system has available If there is no fic channel, the computer is blocked in step 105. Check if there are any channels. If there are no blocked channels, In step 107, the computer denies access to the requesting mobile station. and the request ends. However, if your computer is blocked by a system If it is determined that a channel exists, in step 111 the computer seals the channel. Select a blocked traffic channel and unblock the traffic channel. and thereby enable handling of incoming calls and handoffs.

The computer selects the traffic channels with the longest idle time and the least jammed traffic channels. traffic channel with level or at random. Select the blocked traffic channel by selecting the block channel do.

In step 103, the computer selects at least one capable of handling the incoming call. After determining the two traffic channels, the computer performs step 113. , select one of the available traffic channels.

The computer randomly or randomly selects the longest idle channel. Select one of the available traffic channels by selecting You can do something like that. The computer selects the selected traffic channel in step 115. control the measurement of the strength of any disturbance in the channel. The disturbance level is preferably a trough. sample the dynamic channel every 300ms and calculate the average interference level. It is measured by

The strength of the interference for the selected traffic channel is then determined in step 117. , is compared with the signal strength of the requesting mobile station. In step 119, if The strength of the harm level is at least as strong as the signal strength of the mobile station requesting access. If it is less than a predetermined minimum threshold, the computer will not proceed with the request. assigning the traffic channel to the mobile station that is The request is completed at step 123. In step 119, the computer traffic channel is predetermined from the signal strength of the requesting mobile station. when the computer has a disturbance level higher than the minimum threshold value The data returns to step 103 where the computer selects any available data. Check if the fic channel does not exist. This cycle makes the request until a traffic channel is found that is compatible with the mobile station in use. Otherwise, it continues until the requesting mobile station terminates.

Referring to FIG. 3, a simplified flowchart is shown for M Indicates a subroutine of a computer located either in the SC or in the base station. ing. The computer first enters the traffic channel in step 151. monitor the signal strength of mobile stations requesting access. Access to base station The requested mobile station signal strength is based on the received signal strength of the traffic channel. Adjustments may be necessary due to planned changes. For example, used by mobile stations. The power level of the control channel used by the mobile station for the traffic channel is The signal strength may differ from the one you plan to use. For example, the mobile station Control channel with power level 3 corresponding to -6 dBW in MPS system may come into contact with a base station that uses a network. However, the said traffic of the cell The channel can tolerate a power level of 2 corresponding to -2d BW . As a result, the signal strength of the requesting mobile station increases by 4 dB. In another example, Mobile stations may develop very high signal strengths. Call settings or After do-off, the mobile station power adjustment control for the candidate traffic channel The output power can be reduced, thereby lowering the received signal strength .

The computer determines available traffic channels for the system in step 153. Decide whether to use flannel or not. The available traffic channels are predetermined. It is used in cellular systems to block channels with interference levels exceeding the some unblocked channel or a predetermined level. Already used in cellular systems that do not block channels with interference levels exceeding This is a channel that has not been updated. If the computer or when a request is made If you have determined that there are no traffic channels available for your system, The computer determines whether there are any blocked channels at step 155. do. If there are no blocked channels in the system, the computer The router requests access to the traffic channel in step 157. deny access to the mobile station.

However, if the computer, in step 155, connects the system to a blocked channel, If you decide that a traffic channel exists, your computer will In step 161, unblock the traffic channel and This allows the channel to handle incoming calls and handoffs. . The computer selects the traffic channel with the longest idle time as the one with the least interference. Traffic channels with harmful levels or randomly traffic Select the blocked traffic channel by selecting the block channel do.

In step 153, the computer determines at least one available traffic After determining the channel, the computer, in step 163, Measure the strength of the interference level of all available traffic channels. That's it The interference levels of these traffic channels are determined in step 165. They are arranged according to level from lowest to highest.

At step 167, the computer determines that the traffic channel request has been made. monitor the total amount of traffic activity occurring within the system. compilation In step 169, the computer determines the required amount based on the total traffic activity of the system. The signal strength of the requesting mobile station and the interference level of the selected traffic channel. Assign the lowest threshold for the difference between bells and bells. Level of traffic activity is the function of the number of channels already in use relative to the total number of channels in the cell. determined as a number. For example, the traffic activity of the system is such that the mobile station When requesting access to a network channel, the computer is effectively Set a minimum threshold of 8 dB. However, the system traffic When the optical activity is relatively low, the minimum threshold can effectively be set to 20 dB. , on the other hand, when the traffic activity of the system is relatively high, the minimum threshold is implemented. Qualitatively, it can be set to 16 decibels. In step 171, the computer determines the signal strength of the requesting mobile station on all traffic channels. Compare with level. In step 171, the computer instructs the mobile station to interference level equal to or lower than the signal strength minus the minimum threshold Assign a traffic channel with However, if all measurements The specified traffic channel is the mobile station's signal strength minus the minimum threshold. the program returns to step 153. , determine if there are any new available traffic channels. This service The mobile station finds a traffic channel that is compatible with the requesting mobile station. It continues until the request is ejected or the request ends.

Although the invention has been described in terms of preferred embodiments, the terms used are descriptive terms. and not by way of limitation, and changes within the scope of the amended claims are It is understood that many aspects of the invention may be made without departing from its true scope and spirit. It will be.

Engraving (no changes to the content) Engraving (no changes to the content) Engraving (no changes to the content) Summary book In mobile cellular communication systems, when setting up a new call or when handing over calls to a new traffic channel, resulting in poor transmission quality. It is necessary to avoid blocking new traffic channels that could cause It is. new channels to avoid unnecessary interference with new traffic channels. The signal strength of the mobile station requesting the channel is measured. In addition, available trucks The interference level of the traffic channel is also measured and The signal strength of the mobile station is compared with that of the mobile station. Based on this comparison, the traffic channel traffic check so that the disturbance level is less than or equal to the minimum threshold. A channel is assigned to the mobile station.

Procedural Amendment Form C) Dear Commissioner of the Patent Office, May 12, 2015 IJ 1-Display of incident Mobile cellular communication system quality checkTelephone Actibo Get El M Ericsson 4, agent 6-Number of terms that are reduced by correction 7-Object of correction Description and claims translation international search report

Claims (26)

[Claims] 1. determining the signal strength of the signal between the base station and the calling mobile station; ; A step that measures the level of interference on at least one available traffic channel. With Tep; The signal strength of the calling mobile station is adjusted to interfere with the available traffic channel. a step of comparing the harm level; The mobile station making the call has the minimum signal strength of the mobile station making the call. Allocate traffic channels that have a disturbance level lower than the threshold. Steps to guess; at least one base station and a plurality of mobile stations, characterized in that Select and assign traffic channels for cellular mobile communication systems Method. 2. 2. According to claim 1, the level of interference is based on all available traffic channels. at least one base station and a plurality of mobile traffic channel selection and allocation for a cellular mobile communication system with How to make an assignment. 3. In claim 2, the mobile station making the call is provided with a mobile station making the call. The interference level closest to, but lower than, the station's signal strength minus the minimum threshold. characterized in that it allocates a traffic channel with a bell, at least The infrastructure of a cellular mobile communication system having one base station and multiple mobile stations How to select and assign the search channels. 4. In claim 2, the mobile station making the call is provided with a minimum threshold value. The traffic with the lowest interference level than the signal strength of the mobile station making the call. at least one base station, characterized in that the base station is configured to allocate broadcast channels; Traffic channel of a cellular mobile communication system with multiple mobile stations How to make selections and assignments. 5. In claim 1, the minimum threshold value is determined from the signal strength of the mobile station making the call. traffic channels with a disturbance level equal to or less than The jamming level of the available traffic channels increases one at a time until it detects a traffic channel. at least one base station and a plurality of mobile stations; Traffic channel selection and allocation for cellular mobile communication systems How to do it. 6. In claim 5, the available traffic channels are randomly selected. at least one base station and a plurality of mobile stations, characterized in that Select and assign traffic channels for cellular mobile communication systems Method. 7. In claim 5, which of the available traffic channels is selected based on having the longest idle time, at least Traffic of a cellular mobile communication system with one base station and multiple mobile stations method for selecting and assigning channels. 8. In claim 1, the signal strength of the mobile station making the request is such that the signal strength of the mobile station making the request is a small mobile station characterized in that it is adjusted for scheduled changes in the signal strength of a mobile station A cellular mobile communication system having at least one base station and a plurality of mobile stations How to select and assign traffic channels. 9. In claim 1, the minimum threshold value is a function of a function within a cell or close to a cell. characterized by decreasing as the traffic density within the connected area increases, at least Traffic of a cellular mobile communication system with one base station and multiple mobile stations method for selecting and assigning channels. 10. 2. The minimum threshold value according to claim 1, wherein the minimum threshold value is a cell or an associated area near the cell. When the area is operating in relatively low traffic conditions, the effective at least one base station and a plurality of mobile stations; Selection and allocation of traffic channels for cellular mobile communication systems with How to do it. 11. 2. The minimum threshold value according to claim 1, wherein the minimum threshold value is a cell or an associated area near the cell. When the area is operating under normal traffic conditions, it is effectively set to 18 decibels. at least one base station and a plurality of mobile stations, characterized in that: Select and assign traffic channels for cellular mobile communication systems Method. 12. 2. The minimum threshold value according to claim 1, wherein the minimum threshold value is a cell or an associated area near the cell. When the area is operating at relatively high traffic conditions, the effective at least one base station and a plurality of mobile stations; Selection and allocation of traffic channels for cellular mobile communication systems with How to do it. 13. In claim 1, the signal strength of the mobile station making the request is determined by the base station. at least one base station and a plurality of mobile stations, characterized in that: Selects and allocates traffic channels for cellular mobile communication systems. How to do it. 14. In claim 1, the signal strength of the mobile station making the request is determined by the mobile station. at least one base station and a plurality of mobile stations, characterized in that: Selects and allocates traffic channels for cellular mobile communication systems. How to do it. 15. 2. According to claim 1, the interference level of a traffic channel is determined at a base station. at least one base station and a plurality of mobile stations, characterized in that: Selects and allocates traffic channels for cellular mobile communication systems. How to do it. 16. 2. According to claim 1, the level of interference on a traffic channel is determined at a mobile station. at least one base station and a plurality of mobile stations, characterized in that: Selects and allocates traffic channels for cellular mobile communication systems. How to do it. 17. 2. According to claim 1, the interference level of a traffic channel is at least one base station and a plurality of mobile stations, characterized in that: traffic channel selection and How to make assignments. 18. In claim 17, the signal strength of the requesting mobile station is higher than that of the mobile station. The disturbance level of the traffic channel measured at the base station A cellular mobile device having at least one base station and a plurality of mobile stations, characterized in that: A method for selecting and allocating traffic channels in a dynamic communication system. 19. 2. The method of claim 1, further comprising: a predetermined disturbance level; a step of blocking the traffic channel of the A cellular mobile communication system having at least one base station and a plurality of mobile stations How to select and assign graphic channels. 20. 20. The method of claim 19, further comprising a trough usable in a cellular system. step to unblock a traffic channel when no traffic channel exists. comprising at least one base station and a plurality of mobile stations; Traffic channel selection and allocation for cellular mobile communication systems How to do it. 21. A first measurement to determine the signal strength of the signal between the base station and the calling mobile station. means and; A first step that determines the level of interference of at least one available traffic channel. 2 measuring means; measuring the signal strength of the mobile station making the call; a comparison means for comparing the disturbance level of the channel; The mobile station making the call has the minimum signal strength of the mobile station making the call. Allocate traffic channels that have a lower interference level than the threshold. an allocation means to allocate; at least one base station and a plurality of mobile stations, characterized in that Select and assign traffic channels for cellular mobile communication systems Device. 22. Claim 21, wherein the minimum threshold is within or near a cell. A device characterized in that the traffic density decreases as the traffic density within the relevant area increases. 23. 22. According to claim 21, the minimum threshold is a cell or a cell-nearly related cell. When the area is operating in relatively low traffic conditions, the effective A device characterized in that it is set to a bell. 24. 22. According to claim 21, the minimum threshold is a cell or a cell-nearly related cell. When the area is operating under normal traffic conditions, it effectively reduces to 18 decibels. A device characterized in that it is set. 25. 22. According to claim 21, the minimum threshold is a cell or a cell-nearly related cell. When the area is operating at relatively high traffic conditions, the effective A device characterized in that it is set to a bell. 26. 22. The apparatus of claim 21, further comprising: a traffic channel to be obstructed; means to block channels and to block traffic when demand on the traffic channel increases. and means for unblocking the lock channel.