HK1028144A - A method of and apparatus for controlling transmission signal power of communication signals in a communication system - Google Patents

Description

Method and apparatus for controlling transmission signal power of communication signal in communication system

Background

The present invention relates to a method and apparatus for controlling transmission signal power of a communication signal in a communication system. The present invention is suitable for providing power control in a closed loop communication system.

Description of the related Art

The use of Code Division Multiple Access (CDMA) modulation techniques is one of several techniques for improving communications in the presence of a large number of system users. Other multiple access communication systems are known in the art, such as Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA). However, the spread spectrum modulation technique of CDMA has significant advantages over other modulation techniques used in multiple access communication systems. The use of CDMA techniques in multiple access communication systems is disclosed in U.S. patent No. 4,901,307, entitled "spread spectrum multiple access communication system using satellites and terrestrial repeaters," which is assigned to the assignee of the present invention and is incorporated herein by reference. The use of CDMA techniques in multiple access communication systems is further disclosed in U.S. patent No. 5,103.459 entitled "system and method for generating signal waveforms in a CDMA cellular telephone system," which is also assigned to the assignee of the present invention and is incorporated herein by reference.

CDMA provides a form of frequency diversity by spreading the signal energy over a wide bandwidth, as it is an inherent property of wideband signals. Thus, frequency selective fading affects only a small portion of the CDMA signal bandwidth. Space or path diversity is obtained by means of a mobile station that provides multiple signal paths through simultaneous links from one mobile user or through two or more cell sites. In addition, path diversity can be obtained by exploiting the multipath environment by spread spectrum processing, which allows signals arriving with different propagation delays to be separately received and processed. Examples of path diversity are described in U.S. patent No. 5,101,501 entitled "method and system for providing soft handoff in communications in a CDMA cellular telephone system" and U.S. patent No. 5,109,390 entitled "diversity receiver in a CDMA cellular telephone system," both assigned to the assignee of the present invention and incorporated herein by reference.

If the transmission power of a signal transmitted by a base station to one mobile station is too high, it will cause problems such as interference with other mobile stations. As a result, most base stations have a fixed amount of power to transmit signals and therefore can only transmit to a limited number of mobile stations. On the other hand, if the transmission power of the signal transmitted by the base station is too low, the mobile station may receive multiple erroneous transmission frames. Terrestrial channel fading and other known factors can affect the transmit power of signals transmitted by a base station. As a result, each base station must quickly and accurately adjust the transmit power of the signal transmitted to the mobile station. A method and apparatus for controlling transmit power is disclosed in U.S. patent No. 5,056,109, entitled "method and apparatus for controlling transmit power in a CDMA cellular telephone system," which is assigned to the assignee of the present invention and is incorporated herein by reference.

CDMA communication systems are also capable of exchanging signals with fixed location stations. Typically, these fixed stations use directional antennas and therefore communicate with only some sectors of one or several base stations. In general, a fixed station is not concerned about fading due to the movement of the station. The fixed nature of these fixed stations, their directional antennas, and other factors therefore allow these stations to perform better than other mobile stations. These fixed stations often operate as wireless local loops with their respective base stations and therefore require less overhead from the communication system. As a result, users of fixed stations generally enjoy cheaper services.

Summary of The Invention

In one aspect, the present invention provides a method for use in a communication system having a base station, a base station controller in communication with said base station, at least one fixed location user station and at least one mobile user station, wherein a user of said user station transmits signals to said base station and receives communication signals from said base station to control the transmit signal power of communication signals transmitted by the base station. The invention comprises the following steps: receiving, at the base station, a current signal from the fixed user station or the mobile user station; determining, at the base station controller, whether the current signal was transmitted by the fixed user station; and at the base station, if the current signal is transmitted by the fixed user station, reducing a power threshold of a communication signal transmitted to the fixed user station.

In another aspect, the present invention provides a method for use in a communication system having a base station, at least one fixed location user station and a mobile user station, wherein users of said user stations exchange signals with said base station, said method comprising the steps of: determining whether a currently received signal is transmitted by the fixed user station; and adjusting the signal sent to the fixed user station if the current signal was sent by the fixed user station.

In a further aspect, the present invention provides a system for a communication system having base station means, at least one fixed location user station means and a mobile user station means, wherein a user of said user station means exchanges signals with said base station means, said system comprising: means for determining whether a currently received signal was transmitted by said fixed user station means; and means, coupled to said means for determining, for adjusting the signal transmitted to said fixed user station means if said current signal was transmitted by said fixed user station means.

The present invention also provides a system for a communication system having base station means, at least one fixed location user station means and a mobile user station means, wherein a user of said user station means exchanges signals with said base station means, said system comprising: means for determining whether a currently received signal was transmitted by said fixed user station means; and means, coupled to said means for determining, for adjusting the signal transmitted to said fixed user station means if said current signal was transmitted by said fixed user station means.

The invention also provides a base station for a communication system having at least one fixed location user station and one mobile user station, the base station being arranged to exchange signals with said fixed and mobile stations, comprising: a receiver which receives a current signal from said mobile or fixed user station; a processor coupled to the receiver and configured to determine whether the currently received signal was transmitted by the fixed user station; and a transmitter, coupled to the processor, that reduces the power of a signal sent to the fixed user station if the current signal is sent by the fixed user station.

Further, the present invention provides a controller for a communication system, comprising: a receiver that receives signals from the user devices, the signals received from each user device including information identifying the user device; and a processor that processes the identification information in the signal received from the user device to thereby determine a characteristic of the user device, and causes the transmitter to transmit a signal to the user device, the transmitted signal including control information for controlling operation of the user device.

One embodiment of the present invention allows a base station or base station controller to selectively control the transmit power to or from a remote station based on a determination of whether the remote station is a fixed station or a mobile station. For example, the base station can determine the status of the user, for example, from an electronic number in a registration signal received from the station. If the received electronic number corresponds to a fixed station, the base station decreases one or more power thresholds. Based on these reduced thresholds, the base station thereafter transmits the forward link signal to the fixed station at a lower power level. As a result, the base station can increase its capacity due to the reduced power transmitted to the fixed remote station. Similarly, the remote station can adjust its threshold depending on whether it is operating in a fixed mode or a mobile mode. If the base station determines that the fixed station has moved from its prescribed location, the base station can adjust its threshold accordingly or restrict the communication of the fixed station.

In the illustrated embodiment, the transmit power of the station is controlled by first comparing the signal-to-noise ratio (SNR) received by the station at the base station to a threshold and then transmitting a power control command to increase or decrease the power of the remote station based on the comparison. The SNR threshold is generated by the Frame Error Rate (FER) of the frame received at the remote station. The transmit power of signals transmitted by the base station to the remote station is controlled in accordance with a Forward Link (FL) frame error rate reported by the remote station. The present invention is also applicable to these control methods.

In a broad sense, the invention may be implemented in a communication system having a base station, at least one fixed location user station and one mobile user station. System users of the user stations exchange signals with the base station. The method for controlling the transmission signal power of the transmission communication signal by the base station comprises the following steps: (a) determining whether the currently received signal was transmitted by a fixed user station, and (b) adjusting the signal transmitted to the fixed user station if the current signal was transmitted by the fixed user station.

Brief description of the drawings

The features and advantages of the present invention will become more apparent upon consideration of the following detailed description of one embodiment of the invention taken in conjunction with the accompanying drawings. In the drawings, like elements are identified with like reference numerals.

Fig. 1 illustrates a generic closed loop power control system implementing the present invention.

Fig. 2 is a block diagram of a portion of the closed loop power control system of fig. 1.,

fig. 3 is an exemplary flow chart of one method embodying the present invention for adjusting the transmit power of transmissions between a base station and a fixed station.

Fig. 4 is an exemplary waveform diagram of forward link signals transmitted by a base station to a mobile user station and a fixed user station, and exemplary thresholds, which are minimum, nominal, and maximum values of the thresholds established by the base station based on the classification of the user stations.

Detailed description of the preferred embodiments

A communication system, and in particular, a power control apparatus and method for the same, is described in detail herein. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the relevant art that the present invention may be practiced without these specific details or with additional elements or steps. In other instances, well-known structures and methods are not shown in detail in order to avoid obscuring the invention.

Fig. 1 illustrates an exemplary cellular subscriber communication system 10 in which the present invention may be implemented. The system of fig. 1 preferably uses spread spectrum modulation techniques, such as CDMA, to communicate between remote stations (e.g., mobile telephones) and cell sites or base stations. In fig. 1, a remote station 12 communicates with a user station controller 14 by way of one or more base stations 16a, 16b, etc. Similarly, fixed station 18 communicates with base station controller 14, but only with the aid of one or more base stations, such as base stations 16a and 16 b. Since communication system 10 preferably uses CDMA technology, fixed station 18 preferably communicates with one sector of both base stations 16a and 16b, although fixed stations can communicate with other base stations as needed when conditions arise due to outage, changes in cell layout or load, etc.

The base station controller 14 is coupled to and typically includes interface and processing circuitry for providing system control to the base stations 16a and 16 b. The base station controller 14 can also be coupled to and communicate with other base stations and even other base station controllers. The base station controller 14 is also coupled to a mobile communications switching centre 13, which in turn is coupled to a home location register 15. During registration of each subscriber station at the start of each call, the base station controller 14 and the mobile switching center 13 compare the registration signal received from the subscriber station with data stored in the home location register 15, as is well known in the art and described more fully below.

When system 10 is configured to handle telephone calls, base station controller 14 and mobile switching center 13 route telephone calls from the Public Switched Telephone Network (PSTN) to base station 16a or 16b for delivery to the appropriate mobile station 12 or fixed station 18. In addition, base station controller 14 and mobile switching center 13 have the capability to route calls from mobile station 12 and fixed station 18 to the PSTN and between the mobile station and the fixed station. In summary, base station controller 14 establishes, maintains and terminates radio links with mobile station 12 and fixed station 18, while mobile switching center 13 establishes, maintains and terminates communications with the PSTN. The Mobile Switching Center (MSC)13, the Base Station Controller (BSC)14, and the Home Location Register (HLR)15 are collectively referred to herein as a radio infrastructure (infrastructure).

The base station controller 14 can be coupled to the base stations 16a and 16b by various means, such as dedicated telephone lines, fiber optic links, or microwave communication links. The double-arrow lines shown in fig. 1 represent possible communication links between mobile station 12, fixed station 18, and base stations 16a and 16b, and between the base stations and base station controller 14.

Referring to the block diagram of communication system 10 in fig. 2, fixed station 18 includes an antenna 20 that transmits signals to base stations 16a and 16b and receives signals from base stations 16a and 16 b. Although fig. 2 only shows base station 16b, one skilled in the art will appreciate that base station 16a is constructed in a substantially similar manner and, therefore, the following discussion applies equally to base station 16 a.

Duplexer 22 provides the forward link signal from base station 16b to a fixed station receiver system 24. Receiver system 24 down-converts, demodulates, and decodes the received signal. The receiver system 24 then provides a predetermined parameter or set of predetermined parameters or signals to the control processor 25. Examples of parameters may include measured signal-to-noise ratio (SNR), measured received power, and/or decoder parameters (such as symbol error rate, Yamamoto metric, parity bit check indication). In the illustrated embodiment, the parameter provided by the receiver system 24 is the frame error rate.

The control processor 25 receives the parameters from the receiver system 24 and determines the sufficiency of the parameters. In the preferred embodiment, control processor 25 compares the frame error rate on the forward link to a threshold to determine whether the forward link signal should be increased or decreased and generates a corresponding power level signal. The control processor 25 generates power control commands, which in the illustrated embodiment are binary up/down commands. The power control commands are provided to a transmission system 29, which transmits the commands to the base station 16 b. The power control commands are received at the antenna 30 and then downconverted, filtered, demodulated, and provided to a power control processor 34. The power control processor 34 determines adjustments to the forward link transmit signal based on whether the remote station 18 is a fixed station or a mobile station. In particular, the amount of change in the transmission power when the remote station is a fixed station is smaller than that when the remote station is a mobile station, which is supposed to be such that the fixed station suffers not as much deep fading (deep fade) on the propagation path as the mobile station suffers. Further, in the illustrated embodiment, there is a minimum value of the transmit power threshold above which all signals from the base station are transmitted. In the illustrated embodiment, the minimum value of the fixed station's transmit power threshold is less than the minimum value of the mobile station's transmit power threshold.

Registration circuit 27 provides registration data to control processor 25 that includes an electronic number (ESN) or other unique number assigned to fixed station 18, as described below. Transmitter system 29 encodes, modulates, amplifies, and upconverts the power level signal and ESN with the aid of duplexer 22 and antenna 20. In the illustrated embodiment, transmitter system 29 provides power control commands at predetermined locations of the outgoing reverse link frames. Transmitter system 29 also receives reverse link traffic data which can correspond to voice data from a user of fixed station 18.

In another embodiment, as noted above, the power level signal does not reflect a command to increase or decrease power, but instead reflects the measured received power of the forward link signal, the power control processor 34 compares the power level signal to the nominal, minimum and maximum values of the power level threshold. Based on this comparison, the power control processor 24 generates a forward link transmitter power signal to the forward link transmitter system 36. The forward link transmitter system 36 increases, maintains or decreases the power of the forward link signal in response to the transmitter power signal, depending on the minimum and maximum values of the transmit power level (which is determined by whether the remote station is a fixed station or a mobile station).

In yet another embodiment, fixed station 18 does not provide power control commands back to base station 16 b. But instead performs open loop power control in which the base station 16b monitors the quality of the reverse link channel. As is known, the quality of the forward link is related to the quality of the reverse link channel by differences in frequency-dependent fading, making this control method suboptimal. Thus, the power control processor 343 monitors the quality of the reverse link channel and generates an appropriate transmitter power signal to the forward link transmitter system 36 to control the power of the transmitted forward link signal. The adjustment of the transmission power is determined based on whether the remote station is determined to be a fixed station or a mobile station.

The forward link signal is transmitted by means of a transmit antenna 38. Forward link transmitter system 36 also receives forward link traffic data via antenna 38, which is encoded, modulated, and transmitted by forward link transmitter system 36. In the illustrated embodiment, receiver system 24, transmitter system 29, receiver system 32, and transmitter system 36 are CDMA receivers or transmitters, as described in the illustrated embodiments in U.S. Pat. Nos. 4,901,307 and 5,103,459.

Backhaul transceiver 39 sends the registration message and reverse link traffic to base station controller 14. The registration message includes the ESN of fixed station 18 and, alternatively, a Mobile Identification Number (MIN) (e.g., the "telephone number" of the fixed station), an international mobile subscriber identification number (IMSI), and/or a temporary mobile subscriber identification number (TMSI), all of which uniquely identify remote station 18. The base station controller 14 extracts the ESN, MIN, IMSI and/or TMSI from the registration message and provides the resulting registration data to the mobile switching center 13. Alternatively, the control processor 35 extracts the registration data from the registration signal and provides the data to the mobile switching center 13 through the base station controller 14. Details regarding subscriber station registration in a CDMA system are well known and are described in detail in the provisional specification of telecommunications industry association provisional standard IS-41.

The mobile switching center 13 retrieves the appropriate user profile for the remote station in response to the ESN, MIN, IMSI and/or TMSI. The subscriber profile is stored in a home location register 15 or a visitor location register 27, which forms part of the mobile communications switching centre 13. The visitor location register 27 is effectively a cache or higher speed memory for the subscriber profile located at the mobile switching center 13. Instead, the home location register 15 may be a remote storage device with a database of all subscriber profiles. The home location register 15 then exchanges the subscriber profiles with the respective mobile communications switching centre 13 in the communications system 10.

Each user profile stored at visitor location register 27 and/or home location register 15 includes a respective status or category for each user or station in communication system 10 that indicates whether the station is mobile (such as mobile station 12) or stationary (such as stationary station 18). As described more fully below, during the registration of each new subscriber, the mobile switching center 13 compares all incoming ESNs with the visitor or home location register 15 or 37 to determine whether the subscriber corresponds to a mobile station or a fixed station. If the mobile switching center 13 determines that the new subscriber corresponds to a fixed station, the mobile switching center provides a fixed location condition signal to the control processor 35 via the base station controller 14 and the backhaul transceiver 39. In response to this signal, control processor 35 adjusts the nominal, minimum and maximum values of the power level threshold and adjusts the rate of change and the target FER. In another embodiment, remote station 18 sends a message to base station 16 indicating whether the station is operating in a fixed mode or a mobile mode.

Control processor 35 of base station 16b continuously monitors the quality of the reverse link signal received from fixed station 18. Based on this comparison, control processor 35 sends a power control message to remote station 18. In response to this signal, control processor 25 adjusts the power of the reverse link signal transmitted by transmitter system 29. When control processor 35 determines that the new user corresponds to fixed station 18, the control processor reduces the nominal, minimum and maximum values of the quality measurement threshold with which the control processor compares the quality of the reverse link channel. As a result, control processor 35 sends a power control message to remote station 18 instructing remote station 18 to reduce the power of its reverse link signal.

Unless otherwise indicated below, the construction and operation of the various blocks shown in FIG. 2 are of conventional design. As a result, these blocks need not be described in greater detail herein, as will be apparent to those skilled in the relevant art. For the sake of brevity, such description is omitted so as not to obscure the description of the present invention. Any necessary changes to the blocks of communication system 10 in fig. 2 can be readily made by those skilled in the art from the detailed description provided herein.

Referring to the flow chart of fig. 3, routine 100 executed by communication system 10 adjusts the power level thresholds used by base station 16b and/or remote station 18 in response to the classification of each newly registered user. Those skilled in the relevant art will be able to generate source code based on the flowchart of FIG. 3 and the detailed description provided herein. The routine 100 is preferably stored in a memory (not shown).

In step 102, base station 16b receives a new registration message or signal from a user initially registered with communication system 10. The received signal includes the ESN or other identification number for the new subscriber (e.g., MIN, IMSI, TMSI, etc.). The control processor 35 instructs the backhaul transceiver 39 to transmit a registration signal to the mobile communication switching center 13 through the base station controller.

At step 104, HLR15 or 27 determines the status of the new subscriber. The HLR15 or 27 compares a newly received ESN with some ESNs stored in the visitor or home location register 15 or 27. Based on the comparison, the HLR15 or 27 sends a status indicating message to the mobile switching center 13. If the remote station is a fixed station, the mobile switching center 13 provides a fixed location status signal to the control processor 35 of the base station 16 b.

At step 106, control processor 35 adjusts or decreases the nominal, maximum and minimum values of the power level threshold, which are provided to power control processor 34. Alternatively, after determining that the new user is a fixed station, control processor 35 provides an adjustment signal to power control processor 34, and power control processor 34 uses the nominal, maximum, and minimum values of the lower power level threshold in response thereto.

Thereafter, the lower nominal, maximum and minimum values of these power level thresholds, as well as the other values listed earlier, are used by power control processor 34. The power control processor 34 compares the received power level signal to the nominal and minimum values of the lower power level threshold to generate an appropriate transmitter power signal. As noted above, transmitter system 36 transmits the forward link signal to remote station 18 at these lower power levels in response to the signal. By using a lower power level for remote station 18, base station 16b has increased capacity compared to signals transmitted to remote station 18 at a standard power level.

Referring to fig. 4, an exemplary forward link signal is shown as a signal transmitted by base station 16b to mobile station 12 (shown in phantom) and to fixed station 18 (shown in solid). Base station 16b generally establishes a nominal mobile power threshold value 122, a maximum mobile power threshold value 124, and a minimum mobile power threshold value 126, as shown in fig. 4. However, when the base station 16b determines that the newly registered subscriber corresponds to a fixed station, the base station establishes a fixed power threshold nominal value 132, a fixed power threshold maximum value 134, and a fixed power threshold minimum value 136, which are at levels below the nominal, maximum, and minimum values 122, 124, and 126, respectively, of the mobile power threshold. If the forward link signal is being transmitted at the minimum value of the threshold, the minimum value of the power level threshold is no longer reduced.

The nominal, maximum and minimum values 132, 134 and 136 of the fixed power threshold are preferably established at fixed values that are lower (e.g., 5-15dB lower) than the nominal, maximum and minimum values 122, 124 and 126 of the mobile power threshold, respectively. The actual fixed values at which these thresholds are established are based on a number of factors, including the current capacity of the base station 16b, the presence of external interference within the sector of the base station 16b with which the fixed station is communicating, and the like. In the preferred embodiment, the base station controller 14 determines the nominal, maximum and minimum values 132, 134 and 136 and the thresholds 122, 124 and 126 of the power threshold for the base station 16 b.

Control processor 35 also reduces the nominal, minimum and maximum values of the internal quality threshold it uses to compare the reverse link channel quality. Based on these lower thresholds, control processor 35 generates and transmits a power control message to fixed station 18 which, in response, decreases the transmit power of its reverse link signal. As a result, the signal transmitted by fixed station 18 similarly has lower nominal, minimum and maximum values of power level.

The mobile switching center 13 also determines whether the fixed station 18 has moved from its predetermined location in step 108. For example, a user of fixed station 18 may have improperly moved the fixed station and, for example, operated it as a mobile station. Mobile switching center 13 determines whether fixed station 18 has moved from its intended location by determining whether base station 16b receives a signal from the fixed station via another sector or a signal from another unassigned base station. Alternatively, the base station controller 14 can measure the change in the two-way (round trip) signal delay with the fixed station 187 if the fixed station has moved from its predetermined position.

If so, mobile switching center 13 takes corrective action, such as restricting communication with the present mobile station 18. For example, mobile switching center 13 may instruct base station 16b (or another base station) to drop any call to fixed station 18 that is now moving. In addition, mobile switching center 13 can instruct base station 16b (or another base station) to limit handoffs of fixed station 18 from another base station, to allow the fixed station to send only emergency calls, and so on. In addition, mobile switching center 13 can simply access accounting records for fixed station 18 and provide appropriately increased power levels to these users as their status changes from fixed to mobile.

Various alternative embodiments to the above-described exemplary embodiments are possible. In a first alternative embodiment, the subscriber profile is stored in the home location register 15 and there is a delay between requests from the mobile communications switching centre 13 when the home location register 15 provides it with the appropriate subscriber profile. In this first embodiment, the base station controller immediately moves the new user from the overhead channel to the traffic channel when the mobile switching center 13 properly registers the new user. After determining that the new subscriber is a fixed station 18, the mobile switching center 13 instructs the base station 16b to adjust the minimum and maximum values of its power threshold. However, since the call is already in progress, the nominal value of the power level cannot now be adjusted.

In a second alternative embodiment, all registration and decision functions under routine 100 are performed at base station 16 b. The base station 16b therefore includes a database of subscriber profiles, similar to the home and visitor location registers 15 and 27. Base station 16b receives the ESN from fixed station 18 and compares the ESN to its user profile database to determine that the new user is fixed station 18. The base station 6b thereafter adjusts the nominal, maximum and minimum values of the threshold value down.

While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the invention, as will be recognized by those skilled in the relevant art. For example, the various embodiments described herein can be combined to provide further embodiments. In general, the power control routines described in detail above are illustrative, and thus, one skilled in the art will be able to implement the teachings and concepts of the present invention to create similar routines.

The teachings provided herein of the present invention can be used in other communication systems, not necessarily the CDMA communication system described above. For example, although the invention has been generally described above for use in a CDMA communication system 10, the invention is equally applicable to other digital or analog cellular communication systems. The present invention can also be modified, if necessary, to employ the systems, circuits and concepts of the various patents described above, all of which are incorporated herein by reference as if fully set forth.

These and other changes can be made to the invention in light of the above detailed description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but should be construed to include any communication system that operates under the claims to provide transmit power control. Accordingly, the invention is not to be limited by the disclosure, but instead its scope is to be determined entirely by the following claims.

Claims (37)

1. In a communication system having a base station, a base station controller in communication with the base station, at least one fixed location user station, and at least one mobile user station, wherein a user of the user station transmits signals to the base station and receives communication signals from the base station, a method for controlling transmit signal power of communication signals transmitted by the base station, the method comprising the steps of:

receiving, at the base station, a current signal from the fixed user station or the mobile user station;

determining, at the base station controller, whether the current signal was transmitted by the fixed user station;

at the base station, if the current signal is transmitted by the fixed user station, reducing a power threshold of a communication signal transmitted to the fixed user station.

2. The method of claim 1, wherein said base station controller comprises a mobile communications switching center and a registry of all user stations in said communications system, wherein the step of receiving comprises the step of receiving a unique electronic number assigned to said fixed user station; while

The judging step includes the steps of:

comparing, at said mobile communications switching center, said unique electronic number with said registration, said registration identifying the classification of all subscriber stations as being either mobile or fixed based on the electronic numbers assigned to all subscriber stations; and

determining that the current signal was transmitted by the fixed user station if the unique electronic number corresponds to the fixed user station in the registration.

3. The method of claim 1 wherein said base station transmits said communication signal to said user station in accordance with a nominal value, a maximum value, and a minimum value of a power threshold, and wherein the step of lowering the power threshold comprises lowering each of the nominal value, the maximum value, and the minimum value of said power threshold by a fixed amount.

4. The method of claim 1, further comprising the steps of:

determining, at the base station controller, that the fixed user station has moved from a predetermined location; and

restricting, at the base station, communication of the fixed user station with the communication network.

5. The method of claim 1, wherein the step of receiving the current signal comprises receiving a Code Division Multiple Access (CDMA) spread spectrum signal.

6. The method of claim 1, further comprising the steps of:

at the base station, decreasing a reverse link quality threshold;

comparing, at the base station, the quality of the signal received from the fixed user station to the reduced quality threshold; and

at the base station, sending a power control message to the fixed user station based on the comparing step.

7. A method for use in a communication system having a base station, at least one fixed location user station and a mobile user station, wherein users of said user stations exchange information with said base station, said method comprising the steps of:

determining whether a currently received signal was transmitted by the fixed user station; and

and if the current signal is sent by the fixed user station, adjusting the signal sent to the user station.

8. The method of claim 7, wherein the determining step comprises the steps of:

receiving a unique number assigned to said fixed subscriber station;

comparing said unique number to a database of user stations in said communication system, said database identifying a classification of a user station as being a mobile station or a fixed station based on the number assigned to said user station; and

determining that the current signal was transmitted by the fixed user station if the unique number corresponds to the fixed user station in the database.

9. The method of claim 7 wherein said adjusting step comprises decreasing a maximum value of an energy threshold for signals transmitted to said fixed user station.

10. The method of claim 7, further comprising the steps of:

determining that the fixed user station has moved from a predetermined location; and

if the fixed user station has moved away from the predetermined location, a corrective action is taken.

11. The method of claim 7, further comprising the step of determining that the fixed user station has moved from a predetermined location.

12. The method of claim 7, further comprising the step of performing the determining and adjusting steps at the base station.

13. The method of claim 7, wherein the communication system comprises a smart base station in communication with the base station, and further comprising the step of making the determination and adjustment at the smart base station.

14. The method of claim 7, further comprising the step of receiving a Code Division Multiple Access (CDMA) spread spectrum signal from said fixed user station.

15. The method of claim 7, further comprising the steps of:

lowering a reverse link threshold;

comparing a signal received from said fixed user station to said reduced reverse link threshold; and

and sending a control message to the fixed user station according to the comparison step.

16. A system for use in a communication system having at least one fixed location user station device and a mobile user station device, wherein a user of said user station device is exchanging signals with said base station, said system comprising:

determining means for determining whether a currently received signal was transmitted by said fixed user station means; and

adjusting means, coupled to said determining means, for adjusting the signal sent to said fixed user station means if said current signal is sent by said fixed user station means.

17. The system of claim 16, wherein the system further comprises:

receiving means for receiving a unique number assigned to said fixed subscriber station means;

storage means for identifying a classification of a subscriber station as being a mobile station or a fixed station based on a number assigned to said subscriber station means;

comparing means for comparing said unique number with said assigned number in said storage means; and

means for determining that said current signal was transmitted by said fixed subscriber station means if said unique number corresponds to said fixed subscriber station means in said storage means.

18. The system of claim 16, further comprising means for reducing nominal and minimum values of an energy threshold of said fixed user station means.

19. The system of claim 16, further comprising means for determining that said fixed user station means has moved from a predetermined location.

20. The system of claim 16 further comprising receiving means for receiving Code Division Multiple Access (CDMA) spread spectrum signals from said fixed user station means.

21. A system for use in a communication system having base station means, at least one fixed location user station means and a mobile location user station means, wherein users of said user station means exchange signals with said base station means, said system comprising:

means for determining whether a currently received signal was transmitted by said fixed user station means; and

adjusting means, coupled to said determining means, for adjusting the signal sent to said fixed user station means if said current signal is sent by said fixed user station means.

22. The system of claim 21 wherein said fixed user station is configured to transmit a unique number assigned to said fixed user station, wherein said base station includes a switching center having a memory, said memory identifying a classification of a user station as to whether it is a mobile station or a fixed station based on an assigned number, and said switching center is configured to compare said unique number to said assigned number in said memory and to determine that said current signal was transmitted by said fixed user station if said unique number corresponds to said fixed user station in said memory.

23. The system of claim 21 wherein said base station is configured to reduce nominal and maximum energy thresholds for said fixed user station.

24. The system of claim 21 wherein said base station comprises a base station controller and said base station controller is configured to reduce nominal and maximum energy thresholds for said fixed user station.

25. The system of claim 21 wherein said base station is configured to determine that said fixed user station has moved from a predetermined location and to restrict communication of said fixed user station with said communication system when said fixed user station has moved from said predetermined location.

26. The system of claim 21 wherein said base station is configured to receive a Code Division Multiple Access (CDMA) spread spectrum signal from said fixed user station.

27. The system of claim 21 wherein said base station is configured to lower a reverse link threshold, to compare a signal received from said fixed user station to said reverse link threshold, and to send a control message to said fixed user station based on said comparison.

28. A base station for a communication system having at least one fixed location user station and one mobile user station, said base station for exchanging signals with said fixed and mobile stations, said base station comprising:

a receiver which receives current signals from said mobile and fixed user stations;

a processor coupled to said receiver and configured to determine whether said currently received signal was transmitted by said fixed user station; and

a transmitter coupled to said processor for reducing a signal transmitted from said fixed user station if said current signal is transmitted by said fixed user station.

29. The base station of claim 28 wherein said fixed user station is configured to transmit a unique number assigned to said fixed user station, and

the base station further includes a switching center having a memory coupled to the processor, the memory identifying a classification of a user station as to whether it is a mobile station or a fixed station based on an assigned number, and the switching center is configured to compare the unique number to the assigned number in memory and to determine that the current signal was transmitted by the fixed user station if the unique number corresponds to the fixed user station in the memory.

30. The base station of claim 28 wherein the processor is configured to reduce nominal and maximum values of the energy threshold for the fixed user station.

31. The base station of claim 28 wherein said base station controller is configured to reduce a nominal and maximum value of an energy threshold for said fixed user station and to communicate said reduced nominal and maximum values of said threshold to said processor.

32. The base station of claim 28 wherein said processor is configured to determine that said fixed user station has moved from a predetermined location.

33. The base station of claim 28 wherein said receiver receives a Code Division Multiple Access (CDMA) spread spectrum signal from said fixed user station.

34. The base station of claim 28 wherein the processor is configured to reduce a reverse link threshold, to compare a signal received from the fixed user station to the reduced reverse link threshold, and to send a control message to the fixed user station based on the comparison.

35. A controller for a communication system, the controller comprising:

a receiver for receiving signals from user devices, the signals received from each of the user devices including information identifying the user device;

a transmitter for transmitting a signal to the user device; and

a processor for processing the identification information in the signal received from the user device to thereby determine a characteristic of the user device and for causing the transmitter to transmit a signal to the user device, the transmitted signal including control information for controlling operation of the user device.

36. The controller of claim 35, wherein the transmission signal includes information for controlling the user device to transmit a signal based on the identification information.

37. A controller as claimed in claim 35 or 36, wherein the processor comprises adjustment means for adjusting the signal transmitted by the transmitter to the user device in dependence on the identification information.