MXPA06009767A - Apparatus and method for controlling reverse link interference among access terminals in wireless communications - Google Patents

Abstract

In a wireless communication system, an apparatus and a method are provided for controlling reverse link interference among access terminals that are power controlled by a sector of a base station. In an embodiment, the maximum effective noise power spectral density is used as a parameter for controlling the level of reverse link loading, by setting a reverse activity bit (RAB) to signal the access terminals to reduce their data rates in order to minimize interference between the access terminals if the maximum effective noise power spectral density is above a predetermined threshold.

Description

"APPARATUS AND METHOD FOR CONTROLLING INVERSE LINK INTERFERENCE BETWEEN ACCESS TERMINALS IN COMMUNICATIONS WIRELESS " FIELD OF THE INVENTION The present invention relates in general terms to telecommunications, and more specifically, to controlling the reverse link interference in telecommunications.

BACKGROUND OF THE INVENTION In a typical telecommunications network based on the CDMA 2000 standard lxEV-DO according to the "CDMA2000 High Rate Package Data Inferiorate Specification of the 3rd Generation Partnership Project? 3GPP2" ("3rd Generation Partnership Project 2" 3GPP2"CDMA2000 High Rate Packet Data Air Interface Specification"), 3GPP2 C.S0024 Version 3.0, December 5, 2001, the control of reverse link traffic load from mobile or mobile stations. the access terminals to a base station is determined by a parameter known as the ratio between the total power received in a base station and the thermal noise (ROT - rise-over-thermal). The reverse links of a CDMA 2000 lxEV-DO system are multiplexed by code division (CDM - code division ultiplexed) and therefore are of limited interference. In a limited interference CDM communications system, the reverse link transmission of each access terminal is an interference to other access terminals. An access terminal can transmit at a higher data rate if the level of interference from other access terminals is lower. In addition, if one of the access terminals transmits at a higher data rate, other access terminals may experience more interference from the access terminal that transmits at the higher data rate. It is desirable to achieve three main goals in the design of a CDM network, namely to maximize overall process performance and network transfer in any given sector of a base station, maintain stable reverse link operations, and ensure coverage in the frontier of the network. However, these goals tend to generate conflicts with one another and achieving these goals simultaneously typically requires delicate control of the load within the network. In many practical situations, the ROT relationship can not be the best indicator of the sector load and may not be considered as the only parameter to control the load of reverse link traffic in order to minimize the reverse link interference between the terminals. access while providing adequate process performance and data transfer in a wireless communication system. Therefore, there is a need in the art for a new scheme for controlling the reverse link load in a wireless communication system.

BRIEF DESCRIPTION OF THE INVENTION The embodiments described herein address the aforementioned needs when implementing an apparatus and method in which a maximum effective noise power spectral density is used as a parameter to control the reverse link interference, setting a bit of Inverse activity (RAB) to tell access terminals to reduce their data rates if the maximum effective noise power spectral density is above a predetermined threshold.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified block diagram of a wireless communication system in which the embodiments of the present invention can be implemented; Figure 2 is a flow diagram illustrating one embodiment of the process steps in a method for controlling the reverse link load based on the maximum effective noise power spectral density according to the present invention; and Figure 3 is a flowchart illustrating another embodiment of the process steps in a method for setting an inverse activity (RAB) bit to instruct access terminals to change their data rates to control interference in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION The words "by way of example" as used in the present invention refer to "serving as an example, instance, or illustration". Any mode described herein as "by way of example" does not necessarily have to be interpreted as being preferred or advantageous over other modalities. A high data rate subscriber station (HDR), referred to herein as an access terminal (AT-access terminal), may be mobile or stationary, and may communicate with one or more HDR base stations, also known as modem group transceivers (MPTS - modem pool transceivers). An access terminal transmits and receives data packets by one or more modem group transceivers to an HDR base station controller, also known as a modem pool controller (MPC). Modem group transceivers and modem group controllers are parts of a network called an access network. An access network transports data packets between multiple access terminals. The access network may also connect to additional networks outside the access network, such as a corporate intranet or the Internet, and may transport data packets between each access terminal and such outside networks. An access terminal that has established an active traffic channel connection with one or more base stations is called an active access terminal, and is said to be in a traffic state. It is said that an access terminal that is in the process of establishing an active traffic channel connection with one or more base stations is in a connection establishment state. An access terminal can be any data device that is communicated by a wireless channel or by a wired channel, for example, using optical fiber or coaxial cables. An access terminal can also be any variety of device types, including but not limited to a PC card, a compact flash memory, an external or internal modem, or a wired or wireless telephone. The communication link by which an access terminal sends signals to a base station is called a reverse link. The communication link by which a base station sends signals to an access terminal is called forward link. The modalities are described below by way of example with reference to the reduction of reverse link interference in a wireless communication system in accordance with the CDMA2000 lxEV-DO standard Rev-A, known as the "Air Inferior Specification of Data of Package of High Rate of CDMA2000 of Project 2 of Association of 3rd Generation 3GPP2 '". However, the present invention is applicable to the reduction of reverse link interference in various types of CDMA communication systems. Figure 1 is a simplified block diagram of a wireless communication system which includes a base station 2, a base station controller 4 connected to the base station 2, and a plurality of access terminals 6, 8, 10, 12 communicating with the base station 2. The base station 2 includes at least one antenna 14, a transceiver 16 connected to the antenna 14, a computer 18 connected to the transceiver 16 to calculate a maximum effective noise power spectral density between the terminals of access, and a reverse activity bit adjuster (RAB) 20 connected to computer 18 of maximum effective noise power spectral density and to transceiver 16. Base station 2 may also include various other components of a typical CDMA system not shown explicitly in Figure 1 but known to the person skilled in the art. The base station 2 can transmit signals to the antennas 22, 24, 26 and 28 of the access terminals 6, 8, 10 and 12 through the forward links 30, 32, 34 and 36 and receive signals from the access terminals through the reverse links 38, 40, 42 and 44, respectively. For purposes of simplification of the illustration, Figure 1 shows only a sector antenna 14 associated with the base station 2, although a base station may have several antennas covering all sectors of a cell, and each sector antenna may communicate with a plurality of access terminals simultaneously. In addition, some of the access terminals 6, 8, 10 and 12 may not necessarily be located within the same sector. An access terminal outside a certain sector of a base station can transmit at a sufficiently high power level and contribute significantly to the load of that particular sector, resulting in increased interference to the other access terminals that include the given sector in their active sets. A base station may include a plurality of sectors covered by different antennas, or may include only one sector with a 360 ° coverage by an omni-directional antenna. Figure 2 is a flow chart illustrating an embodiment for controlling the reverse link load based on the maximum effective noise power spectral density according to the present invention. As illustrated in Figure 2, the maximum effective noise power spectral density at each of the access terminals that are controlled by power for a given sector of the base station is determined as indicated in block 50. In one mode, the reverse link load control is achieved using a maximum noise spectral density (Nt / max) without pilot interference cancellation (PIC - pilot interferente cancellation). If the pilot interference cancellation is not implemented, the ratio of the noise power spectral density (Nt, i) of a certain access terminal (i) to the thermal noise power spectral density (No) and interference from other access terminals that contribute significantly to the load of the base station sector is determined by the Equation (1) as explained below: where Nt ,? is the noise power spectral density of the access terminal i, I0 is the total received power spectral density in the base station, Ec, i is the chip power of the access terminal i, N0 is the spectral density of thermal noise power, ECP / -, is the pilot chip energy of the j-th access terminal, which is another access terminal different to the access terminal i itself, and Ec, supplementary information, j is the energy of chip of the complementary information channels of the j-th access terminal. In one modality, complementary information channels include a data request channel (DRC) and an acknowledgment channel (ACK acknowledgment). In another embodiment, the complementary information channels also include a reverse rate indicator channel (RRI) and an auxiliary pilot channel. The chip energy Ec, proprietary information, j is the total chip energy of all complementary information channels. In equation (1), Ec, traf, j is the chip energy of the traffic channels of the jth access terminal. Therefore, the noise power spectral density (Nt, i) at the access terminal i is the sum of the thermal noise power spectral density, N0, and the interference due to transmissions by other access terminals, that is, the sum of the chip energy of channels that include traffic channels, complementary information channels and pilot channels of other access terminals. The chip energy of the channels of the access terminal i is not considered by itself in the calculation of the noise power spectral density Nt, i in the access terminal i. In a mode in which the pilot interference cancellation is not implemented in the base station, an access terminal with minimum chip energy (EC (iriin) is selected from the access terminals that are considered to contribute to the a significant load on the sector, and the total received power spectral density (lo) is measured at the base station.The maximum noise power spectral density (Nt, max?) is calculated according to equation (2) as explains below: Nt, tó - L? ~ ^ c, min (2) In one embodiment, the spectral density ratio of noise power to the thermal noise power spectral density (Nt / i / No) is calculated for each of the access terminals.

In another embodiment, the control of the reverse link load is achieved by using a maximum effective noise spectral density (Nt, m, effective) with pilot interference cancellation (PIC). In a system in which pilot interference cancellation is implemented, the interference experienced by an access terminal may be less because the base station is capable of canceling the interference from the pilot channels of some or all of the access terminals that are controlled by power by a particular sector of the base station. With the cancellation of pilot interference, the effective noise spectral density (Nt, i, effective) at the access terminal i is determined by the equations (3) and (4) as explained below: ' jeAc where Ac is a set of access terminals whose pilot channels can be canceled by the base station. In one embodiment, the set Ac comprises some or all of the access terminals that are controlled by power by the particular sector of the base station. In one mode, not all pilot channels of the access terminals within the Ac set have canceled interference, and aj is a fraction of the number of access terminals that are within the Ac set and whose pilot channels are canceled by the base station. In this embodiment, complementary information channels such as DRC channels, ACK channels, RRI channels or auxiliary pilot channels of the access terminals in the Ac set are not canceled by the base station. In another embodiment, other reverse link channels may be canceled that include one or more data channels from one or more access terminals that are controlled by power by the base station. After the spectral densities of effective noise power are determined, the maximum effective noise power spectral density (Nt, max, effective) between these access terminals is selected from the access terminals as indicated by block 52 in Figure 2. In one embodiment, the ratio of the maximum effective noise power spectral density to the thermal noise power spectral density (Nt, max, effective / No) is selected as a parameter to determine whether the reverse activity bit (RAB -reverse activity bit) must be set to one or zero. After the maximum effective noise power spectral density (Nt, max, effective) is determined, the RAB is established, implying that the RAB is set to one, or is not established, implying that the RAB is set to zero, depending on whether the Nt, max, effective is greater than a predetermined threshold, as indicated by block 54 in Figure 2. If Nt, max, effective is greater than the predetermined threshold, then the RAB is set in one to indicate to all access terminals which power is controlled by the sector in order to decrease their data rates to control the sector load in order to minimize the interference between the access terminals. If Nt, max, effective is less than the predetermined threshold, then the RAB is not established, that is, it is set to zero, to indicate to all access terminals that are controlled by power by the sector that they do not need to produce their data rates in order to control the sector load. In one embodiment, the ratio of the maximum effective noise power spectral density to the thermal noise power spectral density (Nt, max, actual, or No) is compared to a predetermined threshold in order to determine whether it should be established or not the RAB. In one embodiment, only the effective noise power spectral densities of the access terminals that contribute a significant load to the sector are considered, while the access terminals that do not contribute or that only contribute insignificantly with the load of the sector are ignored in determining whether or not the RAB should be established. In one embodiment, only those access terminals that include the determined sector of the base station in their active sets are selected for consideration. The filtered ratio of pilot chip energy to the effective noise power spectral density (Ecp / Nt) per antenna for each of the access terminals under consideration is calculated in a manner known to the person skilled in the art. The filtered ratio (Ecp / Nt) per antenna for each of these access terminals is then compared to a predetermined reference point. If the ratio filtered by antenna (Ecp / Nt) for a particular access terminal is below the predetermined reference point by more than one predetermined compensation, for example, 2dB, then the access terminal is considered irrelevant for the load of the sector and therefore is ignored in the determination of whether the RAB should be established or not. Alternatively, the determination of whether or not an access terminal contributes a significant load to the sector may be based on whether the data request channel insurance (DRCLock) of the access terminal is established or not established. The data request channel (DRC) is a reverse link channel known to the CDMA communications expert. If the DRCLock of an access terminal is not established, then the access terminal can be considered irrelevant for the sector load and therefore it is ignored in the determination of whether or not the RAB should be established. In another alternative, the determination of whether an access terminal contributes a significant load to the sector can be based on the path loss of the filtered reverse link from the access terminal to the base station. For example, the transmit power of the access terminal can communicate with the base station by one of the reverse link channels, and the power received at the base station can be measured directly by the same base station. The filtered path loss for the reverse link from the access terminal to the base station can be calculated in a manner known to the person skilled in the art. The filtered path loss is then compared with a predetermined threshold. If the filtered path loss is above the predetermined threshold, the access terminal is considered irrelevant to the sector load and therefore is ignored in the determination of whether the RAB should be established or not.

In one embodiment, an upper threshold of the ratio between the total power received at a base station and the thermal noise (ROT) (lo / No), which is conventionally defined as the ratio of the total received power spectral density (lo) to the spectral density of thermal noise power (No), it is imposed on the sector in order to avoid overload of neighboring sectors. If the ROT ratio is greater than a predetermined threshold, the RAB is set to one to indicate to all access terminals that are controlled by power by the sector that their data rates decrease regardless of whether the parameter Nt, max, effective / It is not big enough to activate the establishment of the RAB. In a modality, if only one access terminal is active that is controlled by power by the sector, the RAB is not established, that is, it is set to zero, in such a way that the access terminal does not need to reduce its rate of access. data as long as the ROT ratio is below the predetermined threshold in order to avoid overloading neighboring sectors. Figure 3 is a flow chart illustrating another embodiment of the process for determining the RAB in order to instruct access terminals to change their reverse link data rates in order to control the interference between the access terminals. As illustrated in Figure 3, an initial determination is made on which access terminals contribute a significant load to the sector as indicated in block 60. Subsequently, the maximum effective noise power spectral density (Nt, max, effective ) is determined between the access terminals that are considered to contribute a significant load to the sector as indicated in block 62. In one embodiment, the ratio of the maximum effective noise power spectral density to the power spectral density is calculated. of thermal noise (Nt, ma?, effective / No) and used as a parameter to determine if the base station should indicate the access terminals that are controlled by power by the sector in order to reduce their data rates in order to control the loading of the sector. After the maximum effective noise power spectral density (Nt, max, effective) is determined, the RAB is established, implying that the RAB is set to one, or is not established, implying that the RAB is set to zero, depending on whether Nt, ma?, effective is greater than a predetermined threshold, as indicated in block 64 in Figure 3. If Nt, max, effective is less than the predetermined threshold, then the RAB is set in one to tell all access terminals that are controlled by power by the sector to lower their data rates in order to control the interference between the access terminals. If Nt, max, effective is less than the predetermined threshold, the RAB is not established, it is say, it is set to zero, to indicate to all access terminals that are controlled by power by the sector that they do not need to reduce their data rates with object to control the interference between the access terminals. In one embodiment, the ratio of the spectral density I. of maximum effective noise power to the thermal noise power spectral density (Nt, max, effective No) is compared with a predetermined threshold to determine if the RAB should be established or not established. In one mode, only those access terminals that include the sector are selected determined from the base station in their active sets for consideration as potentially access terminals relevant, which can contribute significantly to the sector's burden. The filtered relation of energy of the pilot chip to the power spectral density of effective noise (Ecp / Nt) per antenna for each of the access terminals under consideration is calculated from way known to the person skilled in the art. The filtered ratio (Ecp / Nt) per antenna for each of the access terminals is then compared with a predetermined reference point. If the filtered ratio (Ecp / Nt) per antenna for a particular access terminal is below the predetermined reference point by more than one predetermined compensation, for example, 2dB, then the access terminal is considered irrelevant to the load of the sector and therefore it is ignored in the determination of whether the RAB should be established or not established. Alternatively, the determination of whether or not an access terminal contributes a significant load to the sector can be based on whether the data request channel insurance (DRCLock) of the access terminal is established or not. If the DRCLock of an access terminal is not established, then the access terminal can be considered irrelevant to the load of the sector and therefore is ignored in the determination of whether the RAB should be established or not. In another alternative, the determination of whether or not an access terminal contributes a significant load to the sector can be based on a comparison of the filtered reverse link path loss coming from the access terminal to the base station with a predetermined threshold. If the filtered path loss is above the predetermined threshold, then the access terminal is considered irrelevant to the load of the sector and therefore is ignored in the determination of whether the RAB should be established or not established. In one embodiment, an upper threshold of the ratio between the total power received at a base station and the thermal noise (ROT) (I0 / No) is imposed on the sector in order to avoid overloading neighboring sectors. If the ROT ratio is greater than a predetermined threshold, the RAB is set to one to indicate to all access terminals that are power-controlled by the sector that their data rates decrease regardless of whether Nt / ma?, Cash / It is not large enough to activate the establishment of the RAB. In a modality, if only one access terminal is active that is controlled by power by the sector, the RAB is not established or is set to zero, so that the access terminal does not need to reduce its data rate always and when the ROT ratio is below the predetermined threshold in order to avoid overload of neighboring sectors. Various embodiments of the apparatus and method according to the present invention may be implemented in the CDMA communication system as alternatives to the conventional scheme of RAB-based ROT adjustment to control the sector load with a minuscule amount of additional complexity. The gains in the process performance and data transfer of each sector of a base station can be realized while avoiding the interference between the access terminals. The sequence of the text in any of the claims does not imply that the steps of the process should be executed in a temporal or logical order according to such a sequence unless specifically defined by the language of the claim. The steps of the process can be exchanged in any order without isolating the scope of the invention as long as such an exchange does not contradict the language of the claim and is not logically absurd. In addition, numerical ordinals such as "first", "second", "third", etc. they simply denote different individualities of a plurality and do not imply any order or sequence (a) unless specifically defined by the language of the claim. In addition, words such as "connect", "connected to" and "connections" used to describe a relationship between different elements do not imply that a direct physical connection between these elements must be made. For example, two elements can be connected to each other physically, electronically, logically, or in any other way, by means of one or more additional elements, without isolating themselves from the scope of the invention. Those skilled in the art will understand that information and signals can be represented using any variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that can be referred to throughout the preceding description can be represented by voltages, currents, electromagnetic waves, fields or magnetic particles, photons, or any other combination of them. Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the embodiments described herein may be implemented as electronic hardware, computer software, or combinations of both. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps in general terms of their functionality have been described above. Whether such functionality is implemented as hardware or software depends on the particular application and the design restrictions imposed on the system in general. Those skilled in the art can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be construed as causing an isolation from the scope of the present invention. The various illustrative logic blocks, modules, and circuits, described in connection with the embodiments described herein may be implemented or implemented with a general purpose processor, a digital signal processor (DSP), an application integrated circuit specific (ASIC - application specific integrated circuit), an arrangement of programmable field gates (FPGA - field programmable gate array) or other programmable logic device, discrete logic of gates or transistors, discrete hardware components, or any combination thereof to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The steps of a method or algorithm described in connection with the embodiments described herein may be incorporated directly into hardware, into a software module executed by a processor, or into a combination of the two. A software module can reside in random access memory (RAM), instant memory, read-only memory (ROM), programmable read-only memory erased (EPROM - erasable programmable read-only memory ), electrically erasable programmable read-only memory (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read the information from, and write the information to, the storage medium. Alternatively, the storage medium may be integral to the processor. The processor and storage medium can reside in an ASIC. The ASIC may reside in any part of a communication system, for example, a base station, a base station controller, or an access terminal. Alternatively, the processor and the storage medium may reside as discrete components in any part of the communication system. The above description of the described embodiments is provided to enable the person skilled in the art to make or use the present invention. Various modifications to these modalities will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without being insulated from the spirit or scope of the invention. Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is intended to encompass the broadest scope consisting of the principles and novel features described herein.

Claims (60)

1. NOVELTY OF THE INVENTION Having described the invention as antecedent, the content of the following claims is claimed as property CLAIMS 1. A method for directing the access terminals that are controlled by power by a sector of a base station to change the data rates in reverse link communications from the access terminals to the base station, characterized in the method because it comprises : determining a spectral density of effective noise power (Nt, max, effective) in an access network for one of the access terminals (i) due to a thermal noise power spectral density (N0) and a sum of energy chip (Ec) of all channels except the pilot channels of at least some of the access terminals that are controlled by power by the sector; determining a maximum effective noise power spectral density (Nt, max, effective) between the access terminals; and determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that the data rates change based on the maximum effective noise power spectral density. The method according to claim 1, further characterized in that it comprises the step to determine if any of the access terminals contributes a significant load to the sector. The method according to claim 2, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the step to determine if the sector is included in an active set by the access terminal. The method according to claim 3, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector further comprises the step to calculate a filtered ratio of pilot chip energy to the power spectral density of effective noise (Ecp / Nt) per antenna for the access terminal. The method according to claim 4, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector further comprises the steps to: determine if the ecp / i ratio per antenna of the access terminal is finds below a predetermined reference point by more than one predetermined compensation; and ignoring the access terminal if the ecp / i ratio per antenna of the access terminal is below the predetermined reference point by more than the predetermined compensation. The method according to claim 1, characterized in that the step for determining a maximum effective noise power spectral density (Nt, max, effective) comprises the step to calculate a ratio of the maximum effective noise power spectral density to a thermal noise power spectral density (Nt, max, effective / N0) 7. The method according to claim 6, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all access terminals that are controlled by power by the sector that change the data rates comprises the step to establish the RAB at 1 if the ratio NtrmaX; effective / Not greater than a predetermined threshold of Nt, max, effective / No- 8. The method according to claim 1, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all access terminals that are controlled by power by the sector that change the rates of data purchased nde the step to set the RAB at 1 if a ratio between the total power received at a base station and the thermal noise (ROT) is greater than a predetermined ROT threshold regardless of whether the ratio Nt, ma?, efect? vo / It is not greater than a predetermined threshold Nt, max, efect? Vo / N0. The method according to claim 1, further characterized in that it comprises the steps for: determining if only one access terminal is active that is controlled by power by the sector; and setting the RAB to 0 if only one access terminal is active that is controlled by power by the sector and a ratio between the total power received at a base station and the thermal noise (ROT) is less than a predetermined ROT threshold . 10. A method for directing the access terminals that are controlled by power by a sector of a base station in order to change the data rates in reverse link communications from the access terminals to the base station, characterized the method because includes: determining if any of the access terminals contributes a significant load to the sector; determine a maximum noise power spectral density (Nt, max) between the access terminals that contribute a significant load to the sector, and determine a reverse activity bit (RAB) to indicate to all access terminals that are controlled by power by the sector that change the data rates based on the maximum noise power spectral density. The method according to claim 10, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the step to determine if the sector is included in an active set by the access terminal. The method according to claim 11, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector further comprises the step to calculate a filtered ratio of pilot chip power to a power spectral density of effective noise (ECp / Nt) per antenna for the access terminal. The method according to claim 12, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector further comprises the steps for: determining whether the ecp / Nt ratio per antenna of the access terminal is finds below a predetermined reference point by more than one predetermined compensation; and ignoring the access terminal if the ECp / i ratio per antenna of the access terminal is below the predetermined reference point by more than the predetermined compensation. The method according to claim 10, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the steps for: determining whether a data request channel insurance (DRCLock) of the terminal Access is not established; and ignore the access terminal if the DRCLock of the access terminal is not established. The method according to claim 10, characterized in that the step to determine if any of the access terminals contributes with a significant load to the sector comprises the steps to: determine if a loss of filtered trajectory coming from the access terminal to the station base is above a predetermined threshold; and ignoring the access terminal if the filtered path loss from the access terminal to the base station is above the predetermined threshold. The method according to claim 10, characterized in that the step for determining a maximum noise power spectral density (Nt, ma?) Comprises the steps for: determining a minimum chip energy (Ec, min) between the access terminals that contribute a significant burden to the sector; determining a spectral density of total received power (I0) in the base station; and calculate the maximum noise power spectral density by subtracting EC / min from I0. The method according to claim 16, characterized in that the step for determining a maximum noise power spectral density (Nt, max) further comprises the step to calculate a ratio of the maximum noise power spectral density to a spectral density of thermal noise power (Nt, ma? / No) • 18. The method according to claim 17, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all access terminals that are controlled by power by The sector that changes the data rates comprises the step to establish the RAB at 1 if the ratio Nt, ma? / is not greater than a predetermined threshold. 19. The method according to claim 10, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that change the data rates comprises the step to establish the RAB in 1 if a ratio between the total power received at a base station and the thermal noise (ROT) is greater than a predetermined threshold. The method according to claim 10, characterized in that it further comprises the steps to: determine if only one access terminal is active that is controlled by power by the sector; and set the RAB to 0 if only one access terminal is active that is controlled by power by the sector. 21. A base station apparatus, characterized in that it comprises: means for determining an effective noise power spectral density (Nt, i, effective) for one of the access terminals (i) due to a thermal noise power spectral density (N0) and a sum of chip energy of (Ec) of all channels except the pilot channels of at least some access terminals that are controlled by power by a sector of the base station; means for determining a maximum effective noise power spectral density (Nt, ma?, effective) between the access terminals; and means for determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that the data rates change based on the maximum effective noise power spectral density. 22. The apparatus according to claim 21, further characterized in that it comprises means for determining if any of the access terminals contributes a significant load to the sector. 23. The apparatus according to claim 22, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector comprises means to determine if the sector is included in an active set per access terminal. The apparatus according to claim 23, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector comprises means for calculating a filtered ratio of pilot chip power to the noise power spectral density cash (Ecp / Nt) per antenna for the access terminal. 25. The apparatus according to claim 24, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector further comprises: means for determining whether the ecp / Nt ratio per antenna of the access terminal is below a predetermined reference point by more than one predetermined compensation; and means for ignoring the access terminal if the ecp / Nt ratio per antenna of the access terminal is below the predetermined reference point by more than one predetermined compensation. 26. The apparatus according to claim 21, characterized in that the means for determining a maximum effective noise power spectral density. (Nt, max, effective) comprise means for calculating a ratio of the maximum effective noise power spectral density to a thermal noise power spectral density (Nt, max, effective / N0) - 27. The method according to claim 26 , characterized in that the means for determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that change the data rates comprises means to set the RAB to 1 if the ratio Nt, more, effective is greater than a predetermined threshold Nt, max, effective / No- 28. The apparatus according to claim 21, characterized in that the means for determining a reverse activity bit (RAB) to indicate to all the terminals of Access that are controlled by power by the sector that change the data rates include means to establish the RAB at 1 if a ratio between the total power received at a base station and the thermal noise (ROT) is greater than a predetermined ROT threshold regardless of whether the Nt ratio, max, effective / Not greater than a threshold Nt, max, effective / Not predetermined. The apparatus according to claim 21, further characterized in that it comprises: means for determining if only one access terminal is active that is controlled by power by the sector; and means to set the RAB to 0 if only one access terminal is active that is controlled by power by the sector and a ratio between the total power received at a base station and the thermal noise (ROT) is less than a threshold of Default ROT 30. A base station apparatus, characterized in that it comprises: means for determining whether any plurality of access terminals contributes a significant load to a given sector of the base station; means for determining a maximum noise power spectral density (Nt, max) between the access terminals that contribute a significant load to the sector; and means for determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that the data rates change based on the maximum noise power spectral density. 31. The apparatus according to claim 30, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector comprises means for determining if the sector is included in an active set by the access terminal. 32. The device. according to claim 31, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector further comprises means for calculating a filtered ratio of pilot chip power to an effective noise power spectral density (Ecp). / N) by antenna for the access terminal. The apparatus according to claim 32, characterized in that the means for determining whether any of the access terminals contributes a significant load to the sector further comprises: means for determining whether the ecp / Nt ratio per antenna of the access terminal is found below a predetermined reference point by more than one predetermined compensation; and means for ignoring the access terminal if the ecp / Nt ratio per antenna of the access terminal is below the predetermined reference point by more than one predetermined compensation. 34. The apparatus according to claim 30, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector comprises: means for determining whether a data request channel insurance (DRCLock) of the terminal of Access is not established; and means to ignore the access terminal if the DRCLock of the access terminal is not established. 35. The apparatus according to claim 30, characterized in that the means for determining if any of the access terminals contributes a significant load to the sector comprises: means for determining whether a filtered path loss from the access terminal to the base station is above a predetermined threshold; and means for ignoring the access terminal if the filtered path loss from the access terminal to the base station is above the predetermined threshold. 36. The apparatus according to claim 30, characterized in that the means for determining a maximum noise power spectral density (Nt, max) comprise: means for determining a minimum chip energy (Ec, min) between the access terminals that contribute with a significant burden on the sector; means for determining a spectral density of total received power (lo) in the base station; and means for calculating the maximum noise power spectral density by subtracting ECrmin from lo- 37. The apparatus according to claim 36, characterized in that the means for determining a maximum noise power spectral density (Nma! C) further comprise the means to calculate a ratio of the maximum noise power spectral density to a thermal noise power spectral density (Nt, ma? / No) - 38. The apparatus according to claim 37, characterized in that the means for determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that change the data rates comprise means to set the RAB to 1 if the ratio Nt, more? or is greater than a predetermined threshold. 39. The apparatus according to claim 30, characterized in that the means for determining an inverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that change the data rates comprise means to establish the RAB in 1 if the ratio between the total power received in a base station and the thermal noise (ROT) is greater than a predetermined threshold. 40. The apparatus according to claim 30, further characterized in that it comprises: means for determining if only one access terminal is active that is controlled by power by the sector; and means to set the RAB to 0 if only one access terminal is active that is controlled by power by the sector. 41. A computer-readable medium containing computer executable instructions incorporating a method to indicate to access terminals that are controlled by power by a sector of a base station that the data rates in reverse link communications from the access terminals to the base station, characterized in that it comprises: determining an effective noise power spectral density (Nt, i, effective) in an access network for one of the access terminals (i) due to a spectral density of thermal noise power (No) and a sum of chip energy of (Ec) of all channels except the pilot channels of at least some access terminals that are controlled by power by the sector; determining a maximum effective noise power spectral density (Nt, max, effective) between the access terminals; and determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that the data rates change based on the maximum effective noise power spectral density. 42. The computer readable medium according to claim 41, characterized in that the method further comprises the step to determine if any of the access terminals contributes a significant load to the sector. 43. The computer readable medium according to claim 42, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the step to determine if the sector is included in an active set by the terminal of access. 44. The computer readable medium according to claim 43, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector further comprises the step to calculate a filtered ratio of pilot chip energy to the density Spectral power of effective noise (ECp / Nt) per antenna for the access terminal. 45. The computer readable medium according to claim 44, characterized in that the step to determine if any of the access terminals contributes with a significant load to the sector also comprises the steps for: determining whether the ratio Ecp / Nt per antenna of the terminal Access is below a predetermined reference point by more than one default compensation; and ignoring the access terminal if the ecp / t ratio per antenna of the access terminal is below the predetermined reference point by more than the predetermined compensation. 46. The computer readable medium according to claim 41, characterized in that the step for determining a maximum effective noise power spectral density (Nt, max, effective) comprises the step to calculate a ratio of the maximum effective noise power spectral density to a thermal noise power spectral density (Nt, áx, j / No) - 47. The computer readable medium according to claim 46, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all terminals Accesses that are controlled by power by the sector that change data rates include the step to set the RAB to 1 if the ratio Nt, max, effective is greater than a predetermined threshold Nt, max, effective / No- 48. The computer readable medium according to claim 41, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all access terminals that are controlled by po The sector for changing data rates comprises the step to establish the RAB at 1 if a ratio between the total power received at a base station and the thermal noise (ROT) is greater than a predetermined ROT threshold regardless of whether Nt , ma?, effective / Not greater than a threshold of Nt, max, effective / N0. 49. The computer readable medium according to claim 41, characterized in that the method further comprises the steps to: determine if only one access terminal is active that is controlled by power by the sector; and set the RAB to 0 if only one access terminal is active that is controlled by power by the sector and a relationship between the total power received at a base station and the thermal noise (ROT) is less than a predetermined ROT threshold. 50. A computer readable medium containing executable instructions incorporating a method to indicate to access terminals that are controlled by power by a sector of a base station that change the data rates in reverse link communications from the terminals of access to the base station, characterized the method because it includes: determining if any of the access terminals contributes with a significant load to the sector; determine a maximum noise power spectral density (Nt, max) between the access terminals that contributes a significant load to the sector; and determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that the data rates change based on the maximum noise power spectral density. 51. The computer readable medium according to claim 50, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the step to determine if the sector is included in an active set by the terminal of access. 52. The computer readable medium according to claim 51, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the step to calculate a filtered ratio of pilot chip power to a spectral density of effective noise power (Ecp / Nt) per antenna for the access terminal. 53. The computer-readable medium according to claim 52, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector also comprises the steps for: determining whether the ecp / Nt ratio per antenna of the Access terminal is below a predetermined reference point by more than one predetermined compensation; and ignoring the access terminal if the ecp / Nt ratio per antenna of the access terminal is below a predetermined reference point by more than the predetermined compensation. 5 . The computer readable medium according to claim 50, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the steps for: determining whether a data request channel insurance (DRCLock) of the Access terminal is not established; and ignore the access terminal if the DRCLock of the access terminal is not established. 55. The computer readable medium according to claim 50, characterized in that the step to determine if any of the access terminals contributes a significant load to the sector comprises the steps even: determine if a loss of filtered trajectory coming from the access terminal the base station is above a predetermined threshold; and ignoring the access terminal if the filtered path loss from the access terminal to the base station is above the predetermined threshold. 56. The computer readable medium according to claim 50, characterized in that the step for determining a maximum noise power spectral density (Nt, ma?) Comprises the steps for: determining a minimum chip energy (EC min) between the terminals of access that contribute with a significant load to the sector; determining a spectral density of total received (lo) at the base station; and calculate the maximum noise power spectral density by subtracting ECrmin from I0. 57. The computer-readable medium according to claim 56, characterized in that the step for determining a maximum noise power spectral density (Nt, ma?) Further comprises the step to calculate a ratio of the thermal noise power spectral density ( Nt, max / N0). 58. The computer readable medium according to claim 57, characterized in that the step to determine a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that change the data rates comprises the step to set the RAB to 1 if the ratio Nt, ma? / is not greater than a predetermined threshold. 59. The computer-readable medium according to claim 50, characterized in that the step for determining a reverse activity bit (RAB) to indicate to all access terminals that are power controlled by the sector that change the data rates comprises the step for set the RAB to 1 if a ratio between the total power received at a base station and the thermal noise (ROT) is greater than a predetermined threshold. 60. The computer readable medium according to claim 50, characterized in that the method further comprises the steps for: determining if only one access terminal is active that is controlled by power by the sector; and set the RAB to 0 if only it is activated activates an access terminal that is controlled by power by the sector.