JP2002152103A - Method for evaluating service quality in cdma mobile telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new process capable of making quantitative the quality of a CDMA mobile telephone system and proceeding with steps for improving this system. SOLUTION: In a system for evaluating a service quality in the CDMA mobile telephone system, all places, where deteriorating operation is predicted, in a service area are determined, the level of a service at the place is shown by assigning a value to each of places, where a deteriorated service is predicted, and the levels of services at the respective places, where the deteriorating operation is predicted, in the service area are totaled. Then, the total is divided by the service levels of all the service areas and a value showing the service quality in each of service areas is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the quality of service in a CDMA mobile telephone system.

[0002]

BACKGROUND OF THE INVENTION Currently available commercial mobile communication systems include:
It typically includes a number of fixed base stations (cells), each of which transmits signals to and receives signals from mobile units within its respective communication area.

[0003] Each base station is assigned a number of channels with which it can communicate with the mobile units. Mobile units within the area of the base station use these channels to communicate with the outside world.

[0004] Typically, the groups of channels used by a base station are chosen so that the signals of any channel do not interfere with the signals of another channel used by that base station.

[0005] In order for a mobile unit to be able to transmit and receive telephone communications even when it moves over a wide area, each cell has an adjacent coverage area and overlaps the coverage area of another cell group. As such, they are physically located in a regular manner.

[0006] When a mobile unit moves from the coverage area of one base station to the coverage area of another base station, communication with the mobile unit is performed from one base station to another base station, and the coverage between the base stations. It is transferred within the area where the area overlaps. (Handed off)

It is self-evident that mobile telephone communications between mobile units and cells should be as free of interference as possible. How to achieve this will depend on the characteristics of the particular mobile telephone system.

[0008] The most popular American M
obile Phone System (AMPS)
In, the channel group is defined by frequency. A frequency band having about 400 disparate adjacent FM frequencies is allocated to individual mobile telephone system operators.

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. Used for uplink transmission from one mobile unit to one cell.

Typically, the frequencies assigned to the downlink transmissions for the entire mobile telephone system are immediately aligned next to each other and also immediately aligned next to each other, the frequencies assigned to the uplink transmissions. Groups are separated significantly apart.

In AMPS systems, since the channels are defined by frequency, any particular transmission interference is primarily due to transmissions on the same channel or nearby adjacent channels. To reduce this interference, the operator assigns individual base stations frequency groups that are far enough apart from each other to eliminate interference between the channel groups.

For example, an operator assigns to a base station a set of channels that carry intermediate frequencies separated by a large number (eg, 21).

In addition, in the AMPS system, when a mobile unit moves from the coverage area of a certain base station to the coverage area of another base station, its communication is performed from one base station to another base station, and the cell cover is not transmitted. In the overlapping area,
Because of the transfer, interference with base stations having overlapping cell covers must be removed.

To do this, the channels to be assigned to the neighboring cells are carefully chosen so as to eliminate the same frequency. In this case, in some cases, a group of channels far apart is allocated to the central cell in the above-described manner, and then a pattern is used in which a group of cells surrounding the central cell sequentially increases in number for each group of cells surrounding the central cell. This is achieved by assigning channels.

This creates something reminiscent of the honeycomb pattern of the cells, where the central cell is surrounded by a number of overlapping cells transmitting different frequencies.

A similar cell pattern evolves throughout the system, with each cell surrounding a central cell and each cell acting as a central cell surrounded by overlapping cells, a so-called reuse pattern. Has been created. In such a pattern, interference on the same channel comes from cells that carry useful information, usually a short distance away.

In most mobile telephone systems, especially cells in heavily used metropolitan areas, the location of a single cell includes two or three individual transceiver stations (called "sectors"), Channels can be included, each of which has a channel group frequency assignment as described above.

The antenna in each sector is typically 18
It is designed to have a 0 or 120 degree cover. As used herein, the terms cell, sector, base station are generally used interchangeably, unless the context indicates otherwise.

If the AMPS system includes a significant number of sectorized cells, the central cell 6
It would be possible to assign all different and theoretically non-interfering channels to the cells. However, except for the surrounding cells that are in close proximity to the first central cell, the frequency reuse pattern requires that the channels be replicated in a denser range than in non-sectorized systems.

Another common mobile telephone system is
What is called time division multiple access (TDMA)
Frequency band AMP for all systems in groups
It is assigned in a manner very similar to that of the S system. However, in any frequency band, each base station transmits and receives suddenly during a certain number of discrete intervals or time frames. These time intervals in the frequency band then effectively form individual channel groups.

By using these time intervals, it is ensured that the frequency bands allocated to the individual base stations are different from the frequency band groups allocated to the peripheral base stations, thereby establishing a channel reuse pattern. However, this allows for substantially greater utilization of the frequency band due to the time division process.

A newer mobile telephone system, called code division multiple access (CDMA), uses digital signals to transmit data. All base stations and mobile units in a CDMA system now use the same "extended band" of the 1.25 megacycle frequency band, although other frequency bands are currently proposed for transmitting digital signals. Used.

The information bits of each message are extended using an encoding called a pseudo noise (PN) code.
Throughout the system, each sector uses the same PN code for transmission information coding. Thereby, each sector uses a time offset (commonly referred to as a pseudo-noise (PN) offset) to determine a PN code from a certain repetition start time in the extended message.

Thus, one sector can start coded 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. Similarly, a total of 51
The coded transmission can be started with an offset of up to two units. The transmission in each sector uses one of a number of Walsh codes and further encodes the extension message to evaluate which is a channel that can be effectively separated.

The Walsh code is a mask used for encoding and decoding a message, and is a mask for removing a message transmitted using another Walsh code. Messages on a particular channel are decrypted by applying a mask containing the Walsh and PN codes to the pattern of received message bits starting at the PN offset specified for the particular channel.

A CDMA system offers a number of advantages. One of these advantages is that a mobile unit can use the same information from many different cells or sectors.
It can be received at one time.

Since all transmissions take place in the same frequency band, a mobile unit actually receives all the information available within its range. However, the mobile unit only decrypts information that came to it on the channels.

The 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.

Knowing the Walsh and PN offsets that define the channels desired to be received, a mobile unit can decrypt information from multiple base stations at the same time and only from a single message destined for it. Combine 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. Thereby, CDMA
Provide quite good transmission possibilities.

In both AMPS and CDMA systems, using a frequency reuse plan in the manner described above,
Interference between channels can be reduced. Theoretically, these forms of cell mechanics and channel allocation would result in channel reuse at well-separated distances where there would be no interference between multiple mobile units on the same or adjacent channels. The pattern is allowed to repeat.

Unfortunately, for a number of reasons, even with a well-selected frequency reuse plan, AM
In PS and CDMA systems, interference occurs.

Differences in antenna pattern, power level, scattering, and diffraction of waves 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.

Thus, the boundaries at which the signal strength of the channel falls below a level sufficient to support mobile unit communications vary widely within and from cell to cell.

Thus, the boundaries at which the signal strength of the channel falls below a level sufficient to support mobile unit communications vary widely within and between cells.

For this reason, adjacent cells do not typically form strict geographical boundaries, as described above. Cell boundaries must overlap to provide complete area coverage and to be able to handoff, and because cell boundaries are not clearly defined, theoretically avoid interference. Signals often interfere with each other, even if they originate from cells that are sufficiently far away.

This is particularly practical when sectorized cell patterns are used.
This is because the cells are more dense than in a simple cell pattern.

In some AMPS systems, a first signal on a channel from a distant cell is the second (usually) carrying a mobile telephone message within the coverage area of a cell on the same channel. May interfere with strong signals. 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).

Signals from another cell on a channel having a frequency close to the frequency of the channel carrying mobile telephone messages may interfere. That is when the drop-in strength of the interfering signal coming from the serving signal is below a certain second threshold level. (Typically 6 dB)

In a historical AMPS system,
To determine if interference is present, the operator of the mobile telephone system relies on customer complaints. When a customer registers a sufficiently large number of complaints about communications at a particular location in a system, the operator typically has to pay a considerable amount of money to measure the signal strength received from other cells at the suspect location in the system. Carry out such a field test.

During the test period, the location where the system is being tested is essentially out of communication. Because of its cost and inconvenience, the test is typically limited to suspect areas.

The effectiveness of these tests is highly questionable because such tests are limited to the purpose of determining the interference at those locations where the system operator expects to find the interference.

A major problem with the process is that it does not have a complete understanding of the interference that actually exists in some systems. This is because interference was only tested at those locations where typically strong interference was reported.

The process does not take into account all the signals that may be propagating, such as entering the affected area and interfering with the carrier, and changes in channel assignments are The impact on other places is not taken into account.

This interference cancellation method often (and probably always) only moves the interference elsewhere in the system. Just being discovered because the customer has filed a sufficient number of complaints justifies on-site testing and in a location separate from the newly isolated interference.

In addition, this method of interference rejection is very slow and labor intensive. A medium size interference rejection test would require 400 man hours.

The process does not guarantee that interference will be rejected and adds significantly to cost. Due to the ever-increasing nature of mobile phones, the system changes, such as the frequency of use constantly increasing at a constant rate, which causes interference.

A process has recently been devised. According to it, an AMPS or TDMA system (and part 1)
The quality of the service provided by the part) can be determined in relation to the fixed confirmable quantity. Its purpose is to allow changes to be made to improve the quality of service with the expectation that it will have the desired result of actually improving the quality of service provided by the system That is.

The process uses data on transmitted signal strength and received signal strength collected at each location in the service area during operation of the service area. These values provide practical data for all places where interference may occur.

Knowing where interference can occur,
Knowing the value to be assigned to the specific service area, the operator can quantify the quality of service by that value,
You can decide whether the system needs to be changed.

The process is described below. U.S. patent application Ser. No. 08 / 887,101 entitled "Method for Improving the Operation of Mobile Telephone Systems", Jensen
Filing date July 2, 1997. It has been transferred to the assignee of the present invention.

In theory, unlike other types of systems, CDMA transmissions should be interference free throughout the system. The data is decoded using a mask, which is believed to be able to remove the interfering signal from the digital information.

However, in a CDMA system, all transmissions are carried by bits transmitted on the same frequency band. Thus, the information received by a mobile unit or cell is effectively interference if that information is not destined for the particular receiver.

That is, since the receiver receives all messages generated by transmitters within range, the untranslated messages form interference in a CDMA system.

Typically, prior to decryption, the desired message has a minus 14 compared to the total strength of all received signals.
It should have a strength of dB or more. If the strength of the desired message falls below this, the digital details of the message cannot be extracted from the band.

Encoding the signal provides significant encoding gain. Because each bit of information is extended in each coding level by multiple bits.
A decrypted message that is about 7 dB larger than the interference present after decryption is just the right size to provide a signal of sufficient quality.

Because of the different meanings of interference in different types of mobile telephone systems, the AMPS or T
The method of quantifying the quality of service in a DMA system is not very useful when applied to a CDMA system.

Thus, interference in CDMA systems is now typically eliminated by increasing the number of sectors when transmissions in a sector increase beyond a certain maximum number.

However, the measure of whether a particular sector has the capacity to handle additional transmissions is not very meaningful. Increasing the number of sectors in a system is a costly way of dealing with interference.

Therefore, it is desirable to propose a new process that can quantify the quality of a CDMA mobile telephone system and take steps to improve the system.

[0060]

SUMMARY OF THE INVENTION In view of the current state of the art, it is an object of the present invention to provide a new CDMA mobile telephone system capable of quantifying the quality and taking steps to improve the system. To provide a process.

[0061]

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a system for evaluating the quality of service in a CDMA mobile telephone system, wherein all locations in a service area where a degraded operation is expected are determined. Assigning a value to each location where a degraded service is expected to indicate the level of service at that location; summing the level of service at each location where a degraded operation is expected in the service area; Is divided to obtain a value indicating the service quality of the service area.

[0062]

As a result, the present invention operates as described in detail below.

[0063]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mobile telephone system 10 shown in FIG. 1 has a number of base stations 12 arranged to cover a service area.
have. The outer edge 13 of each base station 12 indicates the effective limit of the communication range. Often these outer edges overlap each other.

Each base station 12 contains at least one cell, which sends and receives communications with mobile units 15 operating within its service area. Often 1
The base stations include a few sectors, each sector having communication facilities for communicating with a number of mobile units. These mobile units are 180
Or in an area partially defined by the antenna pattern angle of 120 degrees. CDMA
All transmissions between base stations and mobile units in the system are digitally encoded and carried in the "wideband" frequency band of 1.25 MHz.

Each message and digital information is augmented with different levels of encoded information. Such a level is called a PN code. Throughout the system, each sector uses the same PN code to encode the transmitted information. The offset in the expanded message (commonly called the pseudo noise (PN) offset)
, Each sector identifies itself. This augmented message is typically from some repetition of the first point established by communication with the satellite navigation system.

Since the sector can start the encoded transmission at the first time, the second sector goes at 1 unit offset from the first time, the third sector at 2 unit offset, and thus up to 512 offset units. is there. By further encoding the expanded message using Walsh codes,
Each message with the sector is effectively placed on a separate channel. By applying Walsh and PN codes, messages on a particular channel
The information is decoded into a receive sale pattern of information bits starting at the specified PN offset for the particular channel.

There are many advantages to a CDMA system of transmission. First, a mobile unit can receive the same message from many different cells or sectors simultaneously. 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 decodes the information on the channel directed to it.

The CDMA mobile unit has a receiver, which can apply many decoding masks simultaneously to the whole band of information received. By knowing which channel it wants to receive, the mobile unit can decode the information from a single message sent by many different sectors and combine that information into a single output message. Thus, even if a message from one sector is lost, the same message from another sector can be received with an appropriate strength. This allows the CDMA system to provide significantly better messages.

[0069] Despite this advantage, CDMA systems also have problems. One of the causes 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 of the messages available within that range. Messages that are not directed to a particular receiver tend to cancel out the desired message.
If the level of a message that is not directed to a particular receiver reaches a level that is more than 14 dB higher than the level of the desired signal before decoding, it becomes difficult to decode the desired message.

In addition, P at a particular PN offset
Even though information directed to the mobile unit using both the N-code mask and the Walsh mask is decoded, those masks cannot completely reject all unwanted incoming communications. The transmission paths differ in length, and there must be enough headroom to detect the signal directed to the mobile unit. This allowance allows interference through the decoding mask. To provide good quality transmission in a CDMA system, it is a useful requirement that the strength of the desired message be maintained at levels greater than 7 dB above the level of any interference received after decoding.

In fact, CDMA systems have the property of increasing or decreasing the power levels in sectors and mobile units to guarantee a 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 above a predetermined limit, the mobile unit signals the sector to increase the strength of the transmission.

The sector does this, but until the sector is warned to increase the side transmission strength,
The signal strength is gradually reduced from a high level. Frame error rate too high, 7 above interference level
When the level reaches an intensity that is less than dB above, the sector automatically increases the power of the signal being transmitted, increasing the level of the received signal with respect to interference and improving signal quality.

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 to increase or decrease the message strength. When the mobile unit is in contact with multiple sectors, the mobile unit receives signals 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 interference free services to the mobile unit, the mobile unit responds to either signal and reduces its signal strength. During this operation, the mobile unit attempts to keep the message at a minimum signal strength that gives high voice quality.

Because of this power control, the signal strength from the desired transmission for all received signals must be theoretically the same over the entire service area. In fact, as long as you have the ability to take advantage of power control, you also have the ability to add channels and users without compromising quality of service. Thus, many sectors already serving a large number of users can add channels and users without increasing interference in transmissions with the mobile unit.

However, if the mobile unit or sector has reached the maximum power level and cannot respond to the power control signal, the ability to adjust the power level will not work. In such a case, transmissions in the system are subject to interference and quality of service is compromised.

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. Also, each sector is limited to the maximum signal strength for any individual signal transmitted to the mobile unit. Similarly, each mobile unit has a limited amount of power that can be transmitted. Thus, whenever the power maximum is reached, the system cannot adjust the power to eliminate interference.

It would be very advantageous to be able to give a quantitative estimate of the quality of service that would be encountered in a CDMA service area. For example, in an AMPS system, the actual strength of all signals to be transmitted between a plurality of cells and a mobile unit at a plurality of locations across all mobile telephone communication systems is measured to determine the actual strength of all signals. Correlating the data indicating the strength of the signal to the physical location where the signal is transmitted, determining the cell transmission signal that can service each location, and determining the frequency used by the cell serving the location to another Determine the cell transmission signal that will interfere with the signal transmitted by the cell serving the location compared to the frequency used by the cell, and determine the frequency used by the cell serving the location It is possible to determine whether to interfere with frequencies used at other locations throughout the system and evaluate that interference throughout the system.

However, unlike AMPS or TDMA systems, the strengths of all signals received at a particular location at the same frequency are measured, and the strengths are compared to determine whether interference occurs at a location. And determining the quality of service by summing the locations presenting the interference is not trivial.

All messages received anywhere in a CDMA system are on the same frequency. At any one time, the number of messages received at the same time can be very large. The most desired messages are automatically adjusted for the unwanted messages so that only useful messages are received. There is no easy way to determine where there is a frequency problem.

The present invention provides a process for evaluating the quality of service provided by a CDMA system, which allows an operator to take steps to improve the quality of service.

As shown in FIG. 2, the process first determines all locations (measurement locations 17 are shown in FIG. 1) where degradation service is expected throughout the system.
To do this, it is determined 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, the maximum sector power allocated by the sector for the individual transmission has already been reached or the maximum mobile unit power has been reached. If so, that place is the place that provides the desired service.

To complete this decision, data associated with signal strength at locations throughout the service is utilized. This may be the same data collected in an AMPS or TDMA system. Alternatively, the data may be data collected especially 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 link the signal to sectors and locations.

The data is collected by a mobile unit as shown in FIG. 4, which drives the area with the scanning receiver and records the received signal with respect to time and position (typically Is a computer). 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 different from the frequency used by other sectors. Thereby, the strength of the message to be determined as the transmission sector is determined.

In a CDMA system, such data is collected using a wideband receiver (referred to as a PN scanning receiver) that can decode the PN offset transmitted by the sector. A broadband receiver measures the strength of a pilot signal continuously transmitted by a base station on a control channel (pilot channel) defined by a particular Walsh code. With these pilot signals, the mobile unit determines which sector to contact.

If a pilot signal is detected on the pilot channel, the arrival time of the message may be another "synchronous"
The PN offset of the transmission is determined as compared to the system's initial time provided on the control channel. Using this PN offset, the transmitting sector can be determined and the strength of the message received at the location from any sector can be determined. All of this data is collected and recorded by a computer attached to a broadband receiver that collects the data.

Once the data has been accumulated, the following operations are performed by computer software designed in accordance with the present invention. 2 and 3 show the work.

Once the transmitted and received signal strengths are obtained, they can be used to determine the path loss from the sector to the location.

In calculating the quality of service in a CDMA system, the strength of all messages (consisting of pilot signals, other control signals and signals directed to the user) received at each location is summed, It gives you the full reception strength at that location. The sum of intensities of all signals in a given location is to construct an interference level (called N _o) at that location.

The strength of the pilot signal Eb, which must be received at that location to give a quality signal, is
Total interference level N _o higher resolution No. signal from the atmospheric consisting level beyond 7dB than can be determined as. Of course, the specific level will depend on the equipment actually used for the task.

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 is an interference problem for the sector.

During the task of calculating the strength of the message from each sector, the running total of the strength of the message from each sector for all locations is aggregated and 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 interference problems for the system.

Finally, all received (interfering) in the sector to determine if the mobile transmitter must supply more than its maximum power to provide a location-to-sector quality signal. Determine the total number of messages. From this sum, a value 7 dB above this sum is calculated to determine the minimum received signal strength required for a quality signal in the sector.

The sum of the minimum received signal strength and 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 an interference problem for the sector. By calculating the required transmission values for each sector that the location is expected to communicate with, it can be determined for each sector in the system that it is expected to communicate that the location has an interference problem.

Once all the locations exhibiting the degradation service are determined, the number of such locations is summed up for the service area. 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 1 / user of the user.
It is expected to have an average communication level of 10. Multiplying this average communication level by the number of problem locations gives the value of the problem location in the service area Note.

In another variation, different location communication levels for the entire system are assigned, depending on the historical and overall assessment of the amount of communication that a particular location has or will encounter. Then, the communication levels for all problem areas in the service area are summed to obtain a total sum.

The total value for the problem location in the service area is divided by the total number of expected users for the service area to give the service area indicating the percentage of problems for a given area given the expected number of users. Is determined. This scoring result is then compared to the 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 whole system, a part, or a service area for a single sector.

[0097]

By using the data actually obtained by driving the system, it is not necessary to make a prediction based on an environment model that does not necessarily indicate any particular system. In addition, according to the method of the present invention, the system can utilize data that is useful for various different usage levels, change the usage level of the usage, and determine the quality of service for a specific service area. Can also. In other words, the service area can be designed without having to collect data again.

[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 illustrating an example of a process according to the present invention.

FIG. 3 is a flowchart showing another example of the process according to the present invention.

FIG. 4 is a model diagram showing an example of a process in which data used for carrying out the present invention is accumulated.

[Explanation of symbols]

 12: Base station 15: Mobile unit

Continued on the front page F term (reference) 5K022 EE01 EE21 EE31 5K042 AA06 CA02 CA13 DA19 EA15 FA15 GA01 GA15 JA01 5K067 AA44 CC10 DD25 DD42 DD43 DD44 DD46 DD51 EE02 EE10 EE46 FF16 GG08 GG09 HH22 JJ13 LL08

Claims (5)

[Claims] 1. A method for evaluating quality of service in a CDMA mobile telephone system, comprising determining all locations in a service area where a degraded operation is expected and assigning a value to each location where a degraded service is expected. To indicate the service level at the location, sum the service levels at each location where degradation is expected in the service area, and divide the sum by the service level of all service areas to indicate the service quality of the service area A signal level quality evaluation method comprising the step of obtaining a value. 2. Determining all locations in the service area where degraded operation is to be expected, determining total interference for each location in the service area from data defining a signal received at the location, Determine the level to give quality transmission at each location, determine the path loss between each location and between each base station, and from the signal level and the path loss that give the quality transmission at the location to each location where a signal is expected. The method according to claim 1, wherein a transmission signal level from each base station is determined, and the maximum channel transmission power is compared with the determined transmission signal level. 3. Determining all locations in the service area where degraded operation is expected, determining total interference for each location in the service area, determining the received signal level, and providing quality transmission at each location. Determine the path loss between each location and between each base station, and use the received signal level to provide quality transmission at the location and the path loss between each location and between each base station to each location where a signal is expected. The transmission signal level from each base station is determined, the maximum channel transmission power is compared with the determined reception signal level, all transmission signal levels from each base station are summed, and all transmission signals from each base station are determined. 3. The method according to claim 2, wherein the sum of the signal levels is compared with a maximum transmission power of the base station. 4. A method for determining all locations in a service area where a degraded operation is expected, using a received signal level to determine a transmission signal level from each base station where a signal is expected to each location, and Providing a quality transmission at the location and a path loss between the location and each base station, summing all message signal levels from each base station, and comparing the sum with the maximum message power of the base station. 2. The method according to 1. 5. Determining all locations in the service area where degraded operation is expected, determining total interference for each base station in the service area from data defining a signal received at the base station; Determine the received signal level to provide quality transmission at each base station, determine the path loss between each location and each base station, and use the received signal level to transmit to each base station where a signal is expected from each location The method of claim 1, wherein the signal level is determined to provide quality transmission at the base station and path loss between the location and the base station, and the power in the channel is compared to the determined signal level.