JP4541522B2 - Method for evaluating quality of service in CDMA mobile telephone systems - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for evaluating quality of service in a CDMA mobile telephone system.
[0002]
[Prior art]
Currently available commercial mobile communication systems typically include a number of fixed base stations (cells), each of which transmits a signal to a mobile unit within the respective communication area from the mobile unit. Receive a signal.
[0003]
Each base station is assigned a number of channels that can be used to communicate with mobile units. Mobile units within the base station's area use these channels to communicate with the outside world.
[0004]
Typically, a plurality of channel groups used in a base station are selected so that a signal group of any channel does not interfere with a signal group of another channel used in the base station.
[0005]
In order for mobile units to be able to send and receive telephone communications even when moving over a wide area, each cell has its coverage area adjacent to each other and overlapping with the coverage area of other cell groups, Normally it is physically positioned.
[0006]
When a mobile unit moves from one base station's coverage area to another base station's coverage area, the communication with the mobile unit overlaps from one base station to another base station. It is transferred in the area to be. (Handed off)
[0007]
It is obvious that the mobile telephone communication between the mobile unit group and the cell group should be prevented from interfering as much as possible. The way to achieve this depends on the characteristics of the individual mobile telephone system.
[0008]
In the most popular American Mobile Phone System (AMPS), channels are defined by frequency. A frequency band having approximately 400 heterogeneous adjacent FM frequencies is allocated to individual mobile telephone system operators.
[0009]
In a typical AMPS system, each channel uses a fixed FM frequency band for downlink transmission from one base station to one mobile unit, and another fixed FM frequency band for one mobile unit. Used for uplink transmission from one to one cell.
[0010]
Typically, the frequency groups assigned to the uplink transmission that are assigned to the downlink transmission for the entire mobile telephone system are immediately aligned adjacent to each other and also immediately adjacent to each other. Separated considerably.
[0011]
In AMPS systems, because a group of channels is defined by frequency, any particular transmission interference is primarily due to transmissions on the same channel or adjacent channels. To reduce this interference, the operator assigns individual base stations frequency groups that are sufficiently distant from each other to eliminate interference between the channel groups.
[0012]
For example, an operator assigns to a base station a set of channels that carry intermediate frequencies separated by a large number (eg, 21) from each other.
[0013]
Moreover, in the AMPS system, when a mobile unit moves from a coverage area of a certain base station to a coverage area of another base station, the communication is an area where cell coverage overlaps from one base station to another base station. In this case, interference with a base station having an overlapping cell cover must be removed because it must be transferred.
[0014]
To do this, the channels assigned to adjacent cells are carefully chosen to remove the same frequency. In this case, a channel group that is largely separated by the above method is assigned to the central cell, and then a pattern in which the number increases sequentially for each cell group surrounding the central cell is used for the cell group surrounding the central cell. This is achieved by assigning channel groups.
[0015]
This creates a central cell reminiscent of a honeycomb pattern of cells surrounded by a number of overlapping cells transmitting different frequencies.
[0016]
A similar cell pattern develops throughout the system, with each cell surrounding the central cell and functioning as a central cell surrounded by overlapping cells, creating a so-called reuse pattern. Yes. In such a pattern, interference on the same channel comes from a cell carrying useful information, usually a distance away.
[0017]
In most mobile phone systems, particularly in the urban areas where there is a high frequency of use, one cell location contains two to three individual transceiving stations (called “sectors”), each of which Channel groups can be included having the frequency assignments of the channel groups described above.
[0018]
Each sector's antenna is typically configured with a 180 or 120 degree cover. In this specification, the terms cell group, sector group, and base station group are generally used interchangeably unless otherwise indicated by context.
[0019]
If the AMPS system includes a significant number of sectorized cells, the six cells surrounding the central cell could all be assigned different and theoretically non-interfering channels. However, except for the surrounding cells that are immediately adjacent to the first central cell, the frequency reuse pattern requires that the channels be replicated in a denser range than the non-sectored system.
[0020]
Another common mobile telephone system, referred to as time division multiple access (TDMA), has a frequency band assigned to the entire system in a manner very similar to the AMPS system assignment method on a group basis. However, in any frequency band, each base station transmits and receives suddenly during a certain number of disjoint intervals or time frames. These time intervals in the frequency band then effectively form individual channel groups.
[0021]
Using these time intervals, channel reuse patterns are established by ensuring that the frequency band ranges assigned to individual base stations are different from the frequency band ranges assigned to neighboring base stations. Allows substantially substantial utilization of the frequency band due to the time division process.
[0022]
Newer mobile telephone systems, called code division multiple access (CDMA), use digital signals to transmit data. All base stations and mobile units in a CDMA system currently use the same “extended band” of the 1.25 megacycle frequency band, although other frequency bands are currently proposed for transmitting digital signals. Use.
[0023]
The information bits of each message are extended using an encoding called a pseudo noise (PN) code. Throughout the entire system, each sector uses the same PN code for transmission information coding. Thus, each sector uses a time offset (commonly referred to as a pseudo noise (PN) offset) to determine the PN code from a certain repeat start time in the extended message.
[0024]
In this way, one sector can start coding transmission at the start time, the second sector is offset by one unit from the start time, the third is offset by two units, and so on. Thus, it is possible to start encoding transmission by offsetting up to 512 units. Transmission in each sector uses the extension message in one of a number of Walsh codes and is further encoded to evaluate which are the channels that can be effectively separated.
[0025]
A Walsh code is a mask that is used for encoding and decoding messages and that removes a message sent using another Walsh code. Messages on a particular channel are decoded by applying a mask containing Walsh and PN codes to the received message bit pattern starting at the PN offset specified for that particular channel.
[0026]
A CDMA system offers a number of advantages. One of these advantages is that a mobile unit can receive the same information at a time from a number of different cells or sectors.
[0027]
Because all transmissions occur in the same frequency band, a mobile unit actually receives all the information available within that range. However, the mobile unit only decodes information destined for it on the channels.
[0028]
A CDMA mobile unit uses a receiver that can apply a number of decryption masks at a time to the entire band of information it receives.
[0029]
Knowing the Walsh and PN offsets that define the channel that it wants to receive, a mobile unit can decrypt information from multiple base stations at the same time, only from a single message addressed to it, and combine that information. To create a single output message. In this way, even if the signal from one sector is weakened, the same message can be received from another sector with appropriate strength. This provides CDMA with a much better transmission possibility.
[0030]
In both AMPS and CDMA systems, frequency reuse plans can be implemented in the manner described above to reduce interference between channels. Theoretically, these forms of cell mechanics and channel allocation allow channel reuse at sufficiently separated distances that eliminate interference between multiple mobile units on the same or adjacent channels. It is allowed to repeat the pattern.
[0031]
Unfortunately, for a number of reasons, interference occurs in AMPS and CDMA systems, even with a well-selected frequency reuse plan.
[0032]
Differences in antenna pattern, power level, scattering, and wave diffraction from cell to cell. Buildings, various other structures, hills, mountains, leafy branches, and other objects cause fluctuations in signal strength within the area covered by the cell.
[0033]
Thus, the boundaries where the channel signal strength falls below a level sufficient to support mobile unit communications vary widely within the cell and from cell to cell.
[0034]
Thus, the boundaries where the channel signal strength falls below a level sufficient to support mobile unit communications vary widely within the cell and from cell to cell.
[0035]
For this reason, adjacent cell groups typically do not typically form a strict geographic boundary, as described above. Cell boundaries must overlap in order to provide full area coverage and to be able to handoff, and theoretically avoid interference because cell boundaries are not clearly defined. Signals often interfere with each other, even if they originate from cells that are far enough apart.
[0036]
This is particularly realistic when sectorized cell patterns are used. This is because the cells are more dense than in a simple cell pattern.
[0037]
In an AMPS system, the first signal on a channel from a distant cell is (usually) the second most powerful carrying mobile phone messages within the coverage area of a cell on the same channel. Sometimes it interferes with the signal. That is when the drop-in strength of the first signal received from the second signal is below a certain threshold level (typically 18 dB).
[0038]
There are times when signals from another cell on a channel having a frequency close to the frequency of the channel carrying the mobile telephone message interfere. That is when the drop-in strength of the interference signal coming from the serving signal is below a certain second threshold level. (Typically 6dB)
[0039]
In historical AMPS systems, mobile phone system operators rely on customer complaints to determine if interference exists.
When a customer has registered a sufficient number of complaints about communication at a particular location in a system, the operator typically spends considerable time measuring the signal strength received from other cells in the suspicious location of the system. Conduct on-site tests.
[0040]
During the test period, the location where the system is being tested is essentially incapable of communication. Because of its cost and inconvenience, the test is typically limited to only suspicious areas.
[0041]
The effectiveness of these tests is highly suspicious because such tests are limited to the purpose of establishing interference at those locations where the system operator expects to find the interference.
[0042]
The main problem of the process is that it does not have a complete understanding of the interference that actually exists in a system. This is because interference has only been tested at those locations where typically strong interference was reported.
[0043]
The process does not take into account all signals that may propagate as they enter the affected area and interfere with the carrier, and changes in channel assignment may not be The effect on the location is not taken into account.
[0044]
This interference cancellation method often (and perhaps always) only moves the interference to another location in the system. Just because it was discovered because the customer filed a sufficient number of complaints, the field test was justified and it was in a different location from where it was newly separated from interference.
[0045]
Not only that, this method of interference rejection is very slow and labor intensive. A medium sized interference rejection test would require 400 man hours.
[0046]
The process has no guarantee that interference will be eliminated and the cost is significantly increased. Due to the characteristics of mobile phones appearing one after another, the system changes, such as an increase in usage frequency constantly and accelerating, which causes interference.
[0047]
A process has recently been devised. Thereby, the quality of service provided by an AMPS or TDMA system (and part thereof) can be determined in relation to a fixed verifiable quantity. The goal is to be able to make changes to improve the quality of service, with the expectation that the quality of service provided by the system will actually produce the desired result. That is.
[0048]
The process uses transmitted and received signal strength data collected at each location in the entire service area during operation of the service area. These values provide practical data for all locations where interference may occur.
[0049]
Knowing where interference may occur, the value to be assigned to the specific service area is known and the operator can quantify the quality of service and determine if the system needs to be changed.
[0050]
The process is described below. U.S. Patent, Application No. 08 / 887,101, entitled "Method for Improving Operation of Mobile Telephone System", E.I. Jensen et al., Filed July 2, 1997. It has already been assigned to the assignee of the present invention.
[0051]
Theoretically, unlike other types of systems, CDMA transmission should be interference free throughout the entire system. Because the data is thought to be able to remove the interference signal from the digital information, it is decrypted using a mask.
[0052]
However, in a CDMA system, all transmissions are carried by bits transmitted over the same frequency band. Thus, the information received by the mobile unit or cell is effectively interference if the information is not directed to the specific receiver.
[0053]
That is, since the receiver receives all message groups generated by senders in range, untranslated message groups create interference in a CDMA system.
[0054]
Typically, before decryption, the desired message should have a strength of minus 14 dB or more compared to the total strength of all received signals. If the desired message strength falls below this, the digital details of the message cannot be extracted from the band.
[0055]
When the signal is encoded, significant coding gain is obtained. Because each bit of information is expanded in each encoding level by multiple bits. A decrypted message that is about 7 dB larger than the interference present after decryption is just good enough to provide a signal of sufficient quality.
[0056]
Due to the different meanings of interference in different types of mobile telephone systems, the method of quantifying the quality of service in AMPS or TDMA systems of the above patent applications is not very useful when applied to CDMA systems.
[0057]
Thus, interference in a CDMA system is typically eliminated by increasing the number of sectors when transmissions in a sector increase beyond a certain maximum number.
[0058]
However, a measure of whether a particular sector has the capacity to handle additional transmissions is considered to be less meaningful. Increasing the number of sectors in a system is expensive as an interference handling method.
[0059]
Therefore, it is desirable to propose a new process that can quantify the quality of a CDMA mobile telephone system and proceed with steps to improve the system.
[0060]
[Problems to be solved by the invention]
In view of the state of the art as described above, an object of the present invention is to provide a new process capable of quantifying the quality of a CDMA mobile telephone system and proceeding with steps to improve the system.
[0061]
[Means for Solving the Problems]
For this reason, the solution of the present invention is a method for evaluating the quality of service in a CDMA mobile telephone system, which determines all places where a degraded operation in a service area is expected, and for which a degraded service is expected. A value is assigned to a location to indicate the level of service at that location, the level of service at each location where degradation behavior is expected in the service area is summed, and the sum is divided by the service level of all service areas. A value indicating the service quality is obtained.
[0062]
[Action]
As a result of such a configuration, the present invention operates as described in detail below.
[0063]
【Example】
The mobile telephone system 10 shown in FIG. 1 has a number of base stations 12 arranged to cover a service area. The outer edge 13 of each base station 12 represents an effective limit of the communication range. Often these outer edges overlap each other.
[0064]
Each base station 12 includes at least one cell, which transmits and receives communications with mobile units 15 operating within its service area. In many cases, one base station includes two to three sectors, and each sector includes communication equipment for communicating with a number of mobile units. These mobile units are present in an area partially defined by an antenna pattern angle of 180 degrees or 120 degrees from the base station. All transmissions between base stations and mobile units in a CDMA system are digitally encoded and carried in a “wideband” frequency band of 1.25 MHz.
[0065]
Each message and digital information is expanded with different levels of encoded information. Such a level is called a PN code. Throughout the system, each sector encodes the transmitted information using the same PN code. Each sector then determines itself using an offset in the expanded message (generally called a pseudo-noise (PN) offset). This expanded message is typically from a certain iteration of the first point established by communication with the satellite navigation system.
[0066]
The sector can start the encoded transmission at the first time, the second sector at one unit offset from the first time, the third sector at two unit offset, and thus up to 512 offset units. Furthermore, by encoding the expanded message using a Walsh code, each message with a sector is effectively placed on a separate channel. By applying Walsh and PN codes, messages on a particular channel are decoded into a received saleter pattern of information bits starting at the PN offset specified for the particular channel.
[0067]
A transmission CDMA system has many advantages. First, the mobile unit can receive the same message simultaneously from many different cells or sectors. Since all messages occur in the same frequency band, the mobile unit actually receives all of the information available within that range. However, the mobile unit only unlocks information on the channel directed to it.
[0068]
The CDMA mobile unit comprises a receiver, which can apply many decoding masks simultaneously to the entire band of information received. Knowing which channel it wants to receive allows the mobile unit to decode information from a single message sent by many different sectors and combine that information to produce a single output message. Thus, even if a message from one sector disappears, the same message can be received from other sectors with an appropriate strength. This allows the CDMA system to provide significantly better messages.
[0069]
Despite this advantage, there are also problems with CDMA systems. One reason is that all messages occur in the same frequency band. Since all messages occur in the same frequency band, the mobile unit will actually receive all messages available within that range. Messages that are not directed to a particular receiver tend to cancel out the desired message. When the level of a message that is not directed to a particular receiver reaches a level that is more than 14 dB greater than the level of the desired signal before decoding, it becomes difficult to decode the desired message.
[0070]
In addition, even if information directed to the mobile unit using both the PN code mask and Walsh mask at a particular PN offset is decrypted, those masks completely reject all unwanted incoming communications. It is not possible. The transmission paths are of different lengths and must be given enough margin to detect signals directed to the mobile unit. This margin allows interference through the solution mask. To provide good quality transmission in a CDMA system, it is a useful requirement that the desired message strength be maintained at a level that is more than 7 dB above the level of all interference received after decoding.
[0071]
In fact, the CDMA system has the property of increasing and decreasing the power level in the sector and mobile unit to ensure clear transmission. The mobile unit measures the strength of the signal by measuring the degree of error (frame rate error) in the received signal. If the error rises beyond a predetermined limit, the mobile unit signals the sector to increase the strength of the transmission.
[0072]
The sector does this, but then gradually reduces the signal strength from a high level until the sector is warned to increase the side transmission strength. If the frame error rate becomes too high and shows a strength that is less than 7 dB above the interference level, the sector will automatically increase the power of the transmitted signal and Increase level to increase signal quality.
[0073]
Similarly, by monitoring the frame error rate, the sector measures the received signal strength from the mobile unit and indicates to the mobile unit whether the message strength should be increased or decreased. When the mobile unit is in contact with multiple sectors, the mobile unit receives a signal from all sectors indicating whether its message strength should be increased or decreased. Since a single strong signal is sufficient to give the mobile unit a service that is unaffected by interference, the mobile unit responds to either signal and reduces its signal strength. During this operation, the mobile unit attempts to keep the message at the minimum signal strength that gives high voice quality.
[0074]
Because of this power control, the signal strength from the desired transmission for all received signals must theoretically be the same throughout the service area. In fact, as long as there is the ability to use power control, there is also the ability to add channels and users without degrading the quality of service. Thus, many sectors already serving a large number of users can add channels and users without increasing interference in transmissions with mobile units.
[0075]
However, the ability to adjust the power level cannot function if the mobile unit or sector has reached its maximum power level and cannot respond to the power control signal. In such cases, transmissions in the system are subject to interference and the quality of service is impaired.
[0076]
More specifically, each sector is assigned a maximum signal strength for all transmissions, and when transmitting at the maximum level, the signal strength cannot be increased. Each sector is also limited to maximum signal strength for any individual signal transmitted to the mobile unit. Similarly, the amount of power that each mobile unit can transmit is also limited. Thus, whenever the power maximum is reached, the system cannot adjust the power to remove the interference.
[0077]
It would be very advantageous to be able to give a quantitative assessment of the quality of service that would be encountered in a CDMA service area. For example, in an AMPS system, all mobile telephone communication systems measure the actual strength of all signals to be transmitted between multiple cells and mobile units at multiple locations, and Correlate the data indicating the strength of the signal to the physical location where the signal is transmitted, determine the cell transmission signal that can serve each location, and determine the frequency used by the cell serving the location Determine cell transmission signals that will interfere with signals transmitted by the cell serving the location compared to the frequencies used by the cell, and the frequency used by the cell serving the location is all mobile communications It can be determined whether to interfere with frequencies used at other locations throughout the system, and the interference can be evaluated throughout the system.
[0078]
However, unlike AMPS and TDMA systems, etc., measure the strength of all signals received at a specific location at the same frequency and compare their strength to determine if interference occurs at a location. It is not easy to determine the quality of service by summing up the places that are presenting interference.
[0079]
All messages received anywhere in the CDMA system are on the same frequency. There may be a very large number of messages received simultaneously at any location. The most desired message is automatically adjusted to the unwanted message and only useful messages are received. There is no easy way to determine where the frequency problem is.
[0080]
The present invention provides a process for assessing the quality of service provided by a CDMA system, which allows an operator to take steps to improve the quality of service.
[0081]
As shown in FIG. 2, the process first determines all locations where degradation service is expected throughout the system (measurement location 17 is shown in FIG. 1). This determines whether one of the three problems that cause degradation in the CDMA system exists. If the maximum power of the sector transmitter amplifier has been reached, then either the maximum sector power allocated by the sector for an individual transmission has already been reached, or the maximum mobile unit power has been reached. If so, that place is the place where the desired service is presented.
[0082]
To complete this determination, data related to signal strength at locations throughout the service is used. This may be the same data collected in an AMPS or TDMA system. Alternatively, it may be data that is particularly collected for evaluating the quality of CDMA in the service area. In any case, the particular data utilized is indicative of the transmitted signal strength of the message in the sector, the received signal strength of the message at the location, and the receiving location. In general, each of these values is completed by timing data that helps to link signals to sectors and locations.
[0083]
Data is collected by the mobile unit as shown in FIG. 4, which drives the area with the scanning receiver and means for recording the received signal with respect to time and position (typically a computer). have. In an AMPS system, such data must be collected, but many parts of the service area are closed and each sector transmits on a single frequency that is different from the frequency used by other sectors. Thereby, the strength of the message to be determined as the transmission sector is determined.
[0084]
In a CDMA system, such data is collected using a wideband receiver (referred to as a PN scan receiver) that can decode the PN offset transmitted by the sector. The strength of the pilot signal transmitted continuously by the base station on the control channel (pilot channel) defined by the broadband receiver tooth specific Walsh code is measured. With these pilot signals, the mobile unit determines the sector to contact.
[0085]
Once a pilot signal is detected on the pilot channel, the arrival time of the message is compared with the initial (initial) time of the system given on the other “synchronous” control channel to determine the PN offset of the transmission. With this PN offset, the transmission sector can be determined and the strength of the message received at any location from any sector can be determined. All of these data are collected and recorded by a computer attached to a broadband receiver that collects the data.
[0086]
Once the data is collected, it is operated as follows by computer software designed according to the present invention. 2 and 3 show the work.
[0087]
Once the transmitted and received signal strengths are obtained, this can be used to determine sector-to-location path loss.
[0088]
In calculating quality of service in a CDMA system, the strength of all messages received at each location (consisting of pilot signals, other control signals and signals directed to the user) are summed up at that location. All reception strengths are given. The sum of all signal strengths at a location is the interference level (N _o Called).
[0089]
The strength of the pilot signal Eb that must be received at that location to give a quality signal is the total interference level N _o Can be determined as a decoded signal higher than a level greater than 7 dB. Of course, the specific level depends on the equipment actually used for the work.
[0090]
The minimum signal strength required at a location is then added to the path loss between the location and the sector to determine the required transmission signal strength for the channel at the sector transmitter. If this power is not available, the sector has already reached its maximum for the channel and the location becomes an interference problem for the sector.
[0091]
During the work of calculating the strength of messages from each sector, the current total of the strength of messages from each sector for all locations is aggregated to see if the previous sector power is maximum for each sector. Is determined. If so, the sector cannot provide adequate signal strength for the multiple mobile units it must service. This results in an interference problem for the system.
[0092]
Finally, all messages received (interfering) in the sector to determine whether the mobile transmitter must provide more than its maximum power to provide a quality signal from the location to the sector. Determine the total. From this sum, a value 7 dB above this sum is calculated to determine the minimum received signal strength required for the quality signal in the sector.
[0093]
This minimum received signal strength plus the path loss to the location indicates the signal strength that must be available at the mobile unit. If this value is greater than the maximum power available at the mobile unit, the location is in interference with the sector. By calculating the required transmission value for each sector where the location is expected to communicate, it can be determined whether the location has an interference problem for each sector in the system that is expected to communicate.
[0094]
Once all locations that exhibit degraded service are determined, the number of such locations for the service area is summed. This sum is multiplied by the average communication level determined from the expected communication for the service area. For example, if a service area provides services to a moving user and there are a total of 100 locations in the service area, each location is expected to have an average communication level of 1/10 of the user. Is done. Multiply this average communication level by the number of problem locations to find the service area During ~ The value of the problem location is obtained.
[0095]
In other alternative embodiments, various location communication levels throughout the system are assigned, depending on the history of the amount of communication that a particular location will have or will encounter, and an overall assessment. Next, the communication level is totaled for all problem areas in the service area to obtain a total.
[0096]
The total value for the problem location in the service area is then divided by the total number of expected users for the service area, and the service area scoring showing the percentage of the problem for the given area. (Score) is determined. This scoring result is then compared with scoring for other service areas to determine whether a particular service area is a service area that should be changed to complete the system. The specific service area may be the entire system, a part, or a service area for a single sector.
[0097]
【The invention's effect】
By using data that is actually obtained by driving the system, it is not necessary to make a prediction based on an environmental model that does not necessarily represent any particular system. Also, according to the method of the present invention, the system can utilize data that is useful for a variety of different usage levels, can change usage usage levels, and determine the quality of service for a particular service area You can also. In other words, the service area can be designed without having to recollect data.
[Brief description of the drawings]
FIG. 1 is a model diagram showing an example of a mobile telephone system to which the method of the present invention is applied.
FIG. 2 is a flowchart showing an example of a process according to the present invention.
FIG. 3 is a flowchart showing another example of a process according to the present invention.
FIG. 4 is a model diagram showing an example of a process for accumulating data used for carrying out the present invention.
[Explanation of symbols]
12: Base station
15: Mobile unit

Claims (4)

A method for quantifying quality of service in a CDMA mobile telephone system comprising:
Collecting signal data from each base station received at each location in the service area;
With an error rate that exceeds a predetermined limit during the service area, determining all locations where the signal interference to each other degradation behavior is expected,
Wherein at each location where degradation behavior is expected, to assign the value of communication level of the user which is determined according to the situation of each location step,
By summing the communication level of the user at each location where the degradation behavior in the service area is expected to obtain a first sum of which indicates the level of the degradation behavior in the whole service area,
Summing user interaction levels for all locations in the service area to obtain a second sum;
By dividing the first sum of the second sum, Ri name includes the step of obtaining a value that indicates the service quality of the service area is the percentage of the degradation action to occur in the service area,
Determining all locations in the service area where a signal interfering degradation operation is expected having an error rate exceeding a predetermined limit;
Determining total interference for each location from data indicative of signals received at each location in the service area;
Determining the received signal level required to provide a good quality transmission at each location;
Determining path loss between each location and each base station;
Using the received signal level to provide good quality transmission at each determined location and the path loss between each determined location and each base station, each to each location where a signal is expected A method comprising determining a transmission signal level from a base station and comparing a maximum channel transmission power with the determined transmission signal level . Wherein with the error rate exceeds a predetermined limit during the service area, determining all locations where the signal interference to each other degradation behavior is expected further
Summing the transmission signal level of the entire hand from each base station,
The method according to claim 1, characterized in that it comprises a step of comparing the maximum transmission power of the sum and the base station of the all the transmission signal level from each base station. A method for quantifying quality of service in a CDMA mobile telephone system comprising:
Collecting signal data received from each base station at each location in the service area;
Determining all locations in the service area where a signal interfering degradation operation with an error rate exceeding a predetermined limit is expected;
Assigning a value of a user's communication level determined according to the situation of each location to each location where the degraded operation is expected;
Summing the user's communication levels at each location where the degraded operation in the service area is expected to obtain a first sum indicating the level of the degraded operation in the entire service area;
Summing user interaction levels for all locations in the service area to obtain a second sum;
Dividing the first sum by the second sum to obtain a value indicating the service quality of the service area, which is the rate at which the degraded operation occurs in the service area;
Determining the having the error rate exceeds a predetermined limit during the service area, all places where the signal degradation behavior interfere is expected,
By using the received signal level to provide a high quality transmission at each location, and a path loss between the respective locations and each base station, determines a transmission signal level from each base station to each location where signal is expected Step,
Summing the transmission signal level of the entire hand from each base station,
Method characterized by comprising the step of comparing the maximum transmission power of該合meter and the base station. A method for quantifying quality of service in a CDMA mobile telephone system comprising:
Collecting signal data received from each location at each base station in the service area;
Determining all locations in the service area where a signal interfering degradation operation with an error rate exceeding a predetermined limit is expected;
Assigning a value of a user's communication level determined according to the situation of each location to each location where the degraded operation is expected;
Summing the user's communication levels at each location where the degraded operation in the service area is expected to obtain a first sum indicating the level of the degraded operation in the entire service area;
Summing user interaction levels for all locations in the service area to obtain a second sum;
Dividing the first sum by the second sum to obtain a value indicating the service quality of the service area, which is the rate at which the degraded operation occurs in the service area;
Determining the having the error rate exceeds a predetermined limit during the service area, all places where the signal degradation behavior interfere is expected,
Determining a total interference for each base station of the service in the area from the data indicating the signal received at the base station,
Determining a received signal level that provides a good quality transmission at each base station ;
Determining a path loss between each location and each base station,
By using the received signal level to provide a high quality transmission at each base station, and a path loss between the respective locations and each base station, determining a transmission signal level from each location to each base station signal is expected Step to do,
A method comprising the step of comparing the transmission power of the channel with the determined transmission signal level.

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