US20020061006A1 - Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio - Google Patents

Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio Download PDF

Info

Publication number
US20020061006A1
US20020061006A1 US10/006,075 US607501A US2002061006A1 US 20020061006 A1 US20020061006 A1 US 20020061006A1 US 607501 A US607501 A US 607501A US 2002061006 A1 US2002061006 A1 US 2002061006A1
Authority
US
United States
Prior art keywords
frequency reuse
loading
determining
communication system
base station
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/006,075
Inventor
Samir Soliman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US10/006,075 priority Critical patent/US20020061006A1/en
Publication of US20020061006A1 publication Critical patent/US20020061006A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W24/00Supervisory, monitoring or testing arrangements
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W16/00Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/02Resource partitioning among network components, e.g. reuse partitioning
    • H04W16/04Traffic adaptive resource partitioning
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02DCLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00Reducing energy consumption in communication networks
    • Y02D30/70Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention relates to digital communications. More particularly, the present invention relates to a novel and improved system and method for monitoring the load in a CDMA system.
  • CDMA code division multiple access
  • PN pseudorandom noise
  • a first frequency band is used for forward channel communications (from the base station to the mobile station), while a second frequency band, different from the first frequency band, is used for reverse channel communications (from the mobile station to the base station).
  • PN pseudorandom noise
  • Power control of the mobile station transmitter consists of two elements: open loop estimation of transmit power by the mobile station, and closed loop correction of the errors in this estimate by the base station.
  • open loop power control each mobile station estimates the total received power on the assigned CDMA frequency channel. Based on this measurement and a correction supplied by the base station, the mobile station transmitted power is adjusted to match the estimated path loss, to arrive at the base station at a predetermined level. All mobile stations use the same process and arrive with equal average power at the base station.
  • uncontrolled differences in the forward and reverse channels such as opposite fading that may occur due to the frequency difference and mismatches in the receive and transmit chains of the mobile station, cannot be estimated by the mobile.
  • each mobile station corrects its transmit power with closed loop power control information supplied by the base station via low rate data inserted into each forward traffic channel.
  • the base station derives the correction information by monitoring the reverse CDMA Channel quality of each mobile station, compares this measurement to a threshold, and requests either an increase or decrease depending on the result. In this manner, the base station maintains each reverse channel, and thus all reverse channels, at the minimum received power needed to provide acceptable performance.
  • An example of a communication system employing the open loop and closed loop power control methods described above is given in U.S. Pat. No. 5,056,109 entitled “Method And Apparatus For Controlling Transmission Power In A CDMA Cellular Mobile Telephone System,” assigned to the assignee of the present invention, and incorporated herein by reference.
  • a predetermined number of radio frequency resources such as transceivers and channel modulator/demodulators (modems) are located at each base station.
  • the amount of resources allocated to a base station depends upon the anticipated traffic loading conditions. For example, a system in a rural area may only have one omni-directional antenna at each base station, and enough channel modems to support eight simultaneous calls.
  • a base station in a dense urban area may be co-located with other base stations, each having several highly directional antennas, and enough modems to handle forty or more simultaneous calls. It is in these more dense urban areas that cell site capacity is at a premium and must be monitored and managed closely in order to provide the most efficient allocation of limited resources while maintaining acceptable quality of communications.
  • Sector/cell loading is the ratio of the actual number of users in the sector to the maximum theoretical number that the sector can support. This ratio is proportional to total interference measured at the receiver of the sector/cell.
  • the maximum number of users that the sector/cell can support is a function of the aggregate signal-to-noise ratio (SNR), voice activity, and interference from other cells.
  • SNR signal-to-noise ratio
  • the individual subscriber unit SNR depends on subscriber unit speed, radio frequency propagation environment, and the number of users in the system. Interference from other cells depends on the number of users in these cells; radio frequency propagation losses and the way users are distributed. Typical calculations of the capacity assume equal SNR for all users and nominal values of voice activity and interference from other cells.
  • SNR changes from user to user and frequency reuse efficiency varies from sector to sector. Hence, there is a need to continuously monitor the loading of a sector or cell.
  • a conventional way to monitor cell site loading conditions is for a person, usually a network engineer or technician employed by a wireless communication service provider, to travel from cell to cell making loading condition readings using specially designed and expensive test equipment.
  • the logged data is then returned to a central processing facility for post-processing and analysis.
  • Some significant drawbacks to this method are that the data can not be evaluated in real-time, and that significant errors are introduced due to propagation effects between the base station and the measurement equipment.
  • this monitoring method only is used in a time-delayed fashion to take corrective action, such as reassigning resources for the future. It does not enable the service provider to take any real-time action to improve loading conditions and their effect on system performance. Additionally, it requires a person to travel to each site serially, thus providing a discontinuous “hit or miss” estimate of the peak loading conditions and consequent system performance depending on whether the visit coincided with the actual (rather than assumed) peak usage times.
  • Another possible way of monitoring cell site loading conditions is accessing the performance data logged by the base station, or the base station controller.
  • this method requires that scarce base station processing resources be diverted to collect and retrieve the loading data. Additionally, it suffers from the non-real time post-processing problems previously mentioned. It also requires that a person visit each cell site serially to retrieve the data.
  • load monitoring can be used to predict approaching system overloads. It can also be used to control the amount of loading in a system and to establish an admission policy for adding users to the system.
  • the admission policy can apply to new users as well as to users already on the system and being handed off since admission of either kind of user can result in exceeding the system capacity.
  • steps can be taken to allocate more resources in response to load monitoring.
  • Load monitoring can also be used to determine peak hour activities in CDMA systems.
  • the present invention is directed to a method and apparatus for monitoring the load on a CDMA communication system having a base station and a plurality of users.
  • a measure of voice activity in the communication system is determined, and a current value of frequency reuse efficiency equal to an initial value of frequency reuse efficiency is provided.
  • a power determination is made according to the determined voice activity and the current value of frequency reuse efficiency.
  • the current value of frequency reuse efficiency is updated using the power determination to provide a new current value of frequency reuse efficiency.
  • the power determination and the update of the frequency reuse efficiency are iteratively repeated until convergence to provide a converged value of frequency reuse efficiency.
  • the load on the communication system is then determined in accordance with the converged frequency reuse efficiency value.
  • the admission of new users to the communication system is controlled using the determined load value, e.g., admission of new users is denied when the load is above a threshold.
  • load values calculated in accordance with the present invention can be stored in order to collect peak hour activities relating to the communication system.
  • FIG. 1 shows a high level overview of the system of the present invention
  • FIGS. 2A and 2B show graphical representations of possible loadings of a CDMA communication system
  • FIG. 3 shows a flow diagram of the method of the present invention.
  • FIG. 4 is a block diagram showing the components of an exemplary base station used for implementing the position tracking system of the present invention.
  • Communication system 9 provides real time monitoring and management of system loading.
  • Base station 4 of communication system 9 is in wireless communication with mobile stations 1 A- 1 D by way of antenna 2 .
  • Mobile stations 1 A- 1 D can be power controlled CDMA cellular telephones as well known in the art.
  • Base station 4 is also in communication with system management center 5 which can contain any personnel and network computers required to perform any monitoring or management functions required within base station 4 .
  • Base station 4 and system management center 5 can communicate by any method known in the art.
  • mobile stations 1 A- 1 D In normal operation of system 9 , mobile stations 1 A- 1 D periodically communicate with base station 4 , either to originate a call, receive a call, or to send or receive various overhead messages to or from base station 4 .
  • peak usage hours such as during the middle of the day, all four mobile stations 1 A- 1 D may be in simultaneous communication with base station 4 , thereby increasing system loading and interference on the reverse link.
  • non-peak usage hours such as during the middle of the night, fewer mobile stations 1 A- 1 D may be in communication with base station 4 at any time, thereby decreasing system loading. It will be understood that there may be fewer or many more than four mobile stations 1 A- 1 D simultaneously communicating with base station 4 depending on the capacity of base station 4 .
  • the system loading and the frequency reuse efficiency in an active CDMA communication system can be monitored.
  • Information about system loading can then be used by a base station controller, a base station, or any other control device to control loading, establish admission policy to the system and collect peak hour activities.
  • traffic channel SNR information available to a cell site modem is used.
  • the energy per bit (E b ) to noise power spectral density (N t ) of a reverse traffic channel i in a sector k of the CDMA system is used.
  • N o W represents the thermal/background noise
  • C i is the power received at the antenna connector of the base station from user i
  • v i is the average voice activity of user i which the base already knows
  • N is the number of simultaneous users in the sector
  • W is the bandwidth of the CDMA waveform
  • R i is the data rate of user i
  • F k is the frequency reuse efficiency of sector k.
  • the voice activity v i is calculated over N frames based on the data rate(s) used for transmission of traffic information from the mobile station during the frames. For example, in a typical CDMA system frames may be transmitted to the base station using one of four rates (i.e., full rate, 1 ⁇ 2 rate, 1 ⁇ 4 rate and 1 ⁇ 8 rate).
  • the mobile station interleaver output stream is time gated to allow transmission of certain interleaver output symbols and deletion of others.
  • the duty cycle of the transmission gate varies with the transmit data rate. When the transmit rate is 1 (full-rate), the transmission gate allows all interleave output symbols to be transmitted.
  • the transmission gate allows one-half of the interleaver output symbols to be transmitted, and so forth.
  • F k Interference ⁇ ⁇ from ⁇ ⁇ units ⁇ ⁇ within ⁇ ⁇ the ⁇ ⁇ cell Total ⁇ ⁇ Interference ⁇ ⁇ from ⁇ ⁇ all ⁇ ⁇ cells ( 7 )
  • Equation (9) represents the ratio of the CDMA power to the total received power. This ratio is defined as the percentage of loading of the CDMA communication system.
  • the frequency reuse efficiency F k is an estimated value. All of the other values of the right side of Equation (9) are known. Thus it is possible to calculate the percentage of loading of the communication system if a value of the frequency reuse efficiency F k is obtained.
  • FIGS. 2A, 2B there are shown graphical representations 10 , 12 .
  • Graphical representations 10 , 12 indicate possible loadings of CDMA sectors.
  • approximately fifty percent of the received power is CDMA power and approximately fifty percent of the total received power is noise (N o W).
  • N o W approximately seventy-five percent of the total received power
  • the percentages of loading of the sectors of FIGS. 2A, 2B are fifty and seventy-five, respectively.
  • Method 50 is preferably implemented in software on a controller coupled to the cell site modem associated with the sector/cell under consideration.
  • a CDMA communication system can estimate the voice activity v i for each reverse traffic channel i in a sector k as shown in block 52 .
  • the reverse traffic channel includes power control groups for transmitting power control information from a mobile station to the base station.
  • a decision can be made by a channel element processor in the base station whether the transmitter of mobile i is on or off during the period of the power control group. This information can be used to determine the voice activity on traffic channel i as shown in equation (6).
  • the ratio of the energy per bit to the noise power spectral density of CDMA communication systems can be determined in different ways. One way is to use instantaneous values of E b /N t . Another involves using set point values of E b /N t .
  • the instantaneous values of E b /N t are obtained from the base station controller and the set point values are obtained from a selector. If the instantaneous values are used, the base station processor can calculate the instantaneous loading using Equation (9) and pass the loading information to an admission control processor. If set point values from the selector are used, the base station controller can use Equation (9) to calculate the load corresponding to the determined set points. It will be understood that the value of the reverse link energy per bit to noise power spectral density required to sustain a specific frame error rate on the reverse traffic channel of user i can be represented as (E b /N t ) i .
  • Equation (8) is used along with Equation 10(A) to calculate the CDMA power of sector k. This calculation is performed in accordance with equation 10(B) using a current value, which is an estimated initial value of frequency reuse efficiency F k (0). A good initial value of F k (0) can be 0.66.
  • the frequency reuse efficiency is updated to produce a new current value as shown in block 60 .
  • the current value of frequency reuse efficiency is updated to provide a new current value of frequency reuse efficiency.
  • the final value of the frequency reuse efficiency is thus determined according to decision 62 .
  • the sector loading is then calculated using the frequency reuse efficiency in the manner set forth in Equation (9).
  • the operations of block 64 can be performed, for example, when two consecutive calculations of frequency reuse efficiency produce the same result within the precision of the processor performing the calculations or when two consecutive calculations of frequency reuse efficiency are within a predetermined threshold of each other.
  • the CDMA communication system can then be controlled, for example, by a base station controller according to the system loading, the frequency reuse efficiency, or any other value obtained using communication system control method 50 as shown in block 66 .
  • the admission of new users to the communication system can be controlled according to the system loading.
  • the system loading can be monitored in order collect information reflecting peak hour activities at a base station.
  • FIG. 4 there is shown a block diagram of the components of an exemplary CDMA base station 400 used for implementing the load monitoring system of the present invention.
  • two receiver systems are utilized with each having a separate antenna and analog receiver for diversity reception.
  • the signals are processed identically until the signals undergo a diversity combination process.
  • the elements within the dashed lines correspond to elements corresponding to the communications between the base station and one mobile station.
  • the first receiver system is comprised of antenna 460 , analog receiver 462 , searcher receiver 464 and digital data receivers 466 and 468 .
  • the second receiver system includes antenna 470 , analog receiver 472 , searcher receiver 474 and digital data receiver 476 .
  • Cell-site control processor 478 is used for signal processing and control. Among other things, cell site processor 478 monitors the signals sent to and received from a mobile station and uses this information to perform the load monitoring calculations described above. Thus, the system of FIG. 3 is preferably implemented in software on cell site processor 478 .
  • Both receiver systems are coupled to diversity combiner and decoder circuitry 480 .
  • a digital link 482 is used to communicate signals from and to a base station controller or data router under the control of control processor 478 .
  • Signals received on antenna 460 are provided to analog receiver 462 , where the signals are amplified, frequency translated and digitized in a process identical to that described in connection with the mobile station analog receiver.
  • the output from the analog receiver 462 is provided to digital data receivers 466 and 468 and searcher receiver 464 .
  • the second receiver system i.e., analog receiver 472 , searcher receiver 474 and digital data receiver 476 ) processes the received signals in a manner similar to the first receiver system.
  • the outputs of the digital data receivers 466 , 476 are provided to diversity combiner and decoder circuitry 480 , which processes the signals in accordance with a decoding algorithm. Details concerning the operation of the first and second receiver systems and the diversity combiner and decoder 980 are described in U.S. Pat. No. 5,101,501 entitled “Method and Apparatus for Providing A Soft Handoff In Communications In A CDMA Cellular Telephone System”, incorporated above. Signals for transmission to mobile units are provided to a transmit modulator 484 under the control of processor 478 . Transmit modulator 484 modulates the data for transmission to the intended recipient mobile station.

Abstract

A system and method for monitoring the load on a CDMA communication system having a base station and a plurality of users. A measure of voice activity in the communication system is determined, and a current value of frequency reuse efficiency equal to an initial value of frequency reuse efficiency is provided. A power determination is made according to the measured voice activity and the current value of frequency reuse efficiency. The current value of frequency reuse efficiency is updated using the power determination to provide a new current value of frequency reuse efficiency. The power determination and the update of the frequency reuse efficiency are iteratively repeated until convergence to provide a converged value of frequency reuse efficiency. The load on the communication system is then determined according to the converged frequency reuse efficiency value.

Description

    CROSSREFERENCE
  • The present Application for Patent is related to the now allowed U.S. patent application Ser. No. 09/327,103, entitled “MONITORING OF CDMA LOAD AND FREQUENCY REUSE BASED ON REVERSE LINK SIGNAL-TO-NOISE RATIO,” assigned to the assignee hereof and hereby expressly incorporated by reference herein.[0001]
  • BACKGROUND OF THE INVENTION
  • I. Field of the Invention [0002]
  • The present invention relates to digital communications. More particularly, the present invention relates to a novel and improved system and method for monitoring the load in a CDMA system. [0003]
  • II. Description of the Related Art [0004]
  • In the field of code division multiple access (CDMA) wireless communication, a wideband frequency channel is shared by multiple communication devices, with each communication device employing a different pseudorandom noise (PN) spreading code. In a typical CDMA wireless communication system, a first frequency band is used for forward channel communications (from the base station to the mobile station), while a second frequency band, different from the first frequency band, is used for reverse channel communications (from the mobile station to the base station). An example of such a system is given in U.S. Pat. No. 4,901,307 entitled “Spread Spectrum Multiple Access Communication System Using Satellite Or Terrestrial Repeaters,” issued Feb. 13, 1990, assigned to the assignee of the present invention, and incorporated herein by reference. [0005]
  • Fundamental to the concept of maximizing system capacity in a CDMA wireless communication system as described above is the process of power control. The output power of subscriber units must be controlled to guarantee that enough signal strength is received at the base station and to maintain good quality audio while minimizing the potential for interference. Since a CDMA wideband channel is reused in every cell, self interference caused by other users of the same cell and interference caused by users in other cells is the most limiting factor to the capacity of the system. Due to fading and other channel impairments, maximum capacity is achieved when the signal-to-noise ratio (SNR) for every user is, on the average, at the minimum point needed to support “acceptable” channel performance. Since noise spectral density is generated almost entirely by the interference from other users, all signals must arrive at the CDMA receiver with the same average power. In the mobile propagation environment, this is achieved by providing dynamic power control of the mobile station transceiver. Power control guards against changes in system loading, jamming, slow and fast variations in channel conditions, and sudden improvements or degradations in the channel (shadowing). [0006]
  • Power control of the mobile station transmitter consists of two elements: open loop estimation of transmit power by the mobile station, and closed loop correction of the errors in this estimate by the base station. In open loop power control, each mobile station estimates the total received power on the assigned CDMA frequency channel. Based on this measurement and a correction supplied by the base station, the mobile station transmitted power is adjusted to match the estimated path loss, to arrive at the base station at a predetermined level. All mobile stations use the same process and arrive with equal average power at the base station. However, uncontrolled differences in the forward and reverse channels, such as opposite fading that may occur due to the frequency difference and mismatches in the receive and transmit chains of the mobile station, cannot be estimated by the mobile. [0007]
  • To reduce these residual errors, each mobile station corrects its transmit power with closed loop power control information supplied by the base station via low rate data inserted into each forward traffic channel. The base station derives the correction information by monitoring the reverse CDMA Channel quality of each mobile station, compares this measurement to a threshold, and requests either an increase or decrease depending on the result. In this manner, the base station maintains each reverse channel, and thus all reverse channels, at the minimum received power needed to provide acceptable performance. An example of a communication system employing the open loop and closed loop power control methods described above is given in U.S. Pat. No. 5,056,109 entitled “Method And Apparatus For Controlling Transmission Power In A CDMA Cellular Mobile Telephone System,” assigned to the assignee of the present invention, and incorporated herein by reference. [0008]
  • In a CDMA wireless communication system as described above, a predetermined number of radio frequency resources, such as transceivers and channel modulator/demodulators (modems) are located at each base station. The amount of resources allocated to a base station depends upon the anticipated traffic loading conditions. For example, a system in a rural area may only have one omni-directional antenna at each base station, and enough channel modems to support eight simultaneous calls. On the other hand, a base station in a dense urban area may be co-located with other base stations, each having several highly directional antennas, and enough modems to handle forty or more simultaneous calls. It is in these more dense urban areas that cell site capacity is at a premium and must be monitored and managed closely in order to provide the most efficient allocation of limited resources while maintaining acceptable quality of communications. [0009]
  • Sector/cell loading is the ratio of the actual number of users in the sector to the maximum theoretical number that the sector can support. This ratio is proportional to total interference measured at the receiver of the sector/cell. The maximum number of users that the sector/cell can support is a function of the aggregate signal-to-noise ratio (SNR), voice activity, and interference from other cells. The individual subscriber unit SNR depends on subscriber unit speed, radio frequency propagation environment, and the number of users in the system. Interference from other cells depends on the number of users in these cells; radio frequency propagation losses and the way users are distributed. Typical calculations of the capacity assume equal SNR for all users and nominal values of voice activity and interference from other cells. However, in real systems, SNR changes from user to user and frequency reuse efficiency varies from sector to sector. Hence, there is a need to continuously monitor the loading of a sector or cell. [0010]
  • A conventional way to monitor cell site loading conditions is for a person, usually a network engineer or technician employed by a wireless communication service provider, to travel from cell to cell making loading condition readings using specially designed and expensive test equipment. The logged data is then returned to a central processing facility for post-processing and analysis. Some significant drawbacks to this method are that the data can not be evaluated in real-time, and that significant errors are introduced due to propagation effects between the base station and the measurement equipment. Thus, this monitoring method only is used in a time-delayed fashion to take corrective action, such as reassigning resources for the future. It does not enable the service provider to take any real-time action to improve loading conditions and their effect on system performance. Additionally, it requires a person to travel to each site serially, thus providing a discontinuous “hit or miss” estimate of the peak loading conditions and consequent system performance depending on whether the visit coincided with the actual (rather than assumed) peak usage times. [0011]
  • Another possible way of monitoring cell site loading conditions is accessing the performance data logged by the base station, or the base station controller. However, this method requires that scarce base station processing resources be diverted to collect and retrieve the loading data. Additionally, it suffers from the non-real time post-processing problems previously mentioned. It also requires that a person visit each cell site serially to retrieve the data. [0012]
  • One alternate method for monitoring loading in CDMA systems that is known in the prior art is the use of a dedicated channel. However, this solution is very expensive since the capacity of the dedicated channel cannot be used for any other purposes. Consequently, a better way to monitor loading of CDMA communication systems is needed. These problems and deficiencies are clearly found in the art and are solved by the invention in the manner described below. [0013]
  • Thus it is desirable to provide a better way to perform load monitoring in CDMA systems wherein a base station determines the total amount of interference in its frequency band that it receives from all the other transmitters in the system. The load monitoring performed this way can be an important aspect of the operation and maintenance of CDMA systems. For example, load monitoring can be used to predict approaching system overloads. It can also be used to control the amount of loading in a system and to establish an admission policy for adding users to the system. The admission policy can apply to new users as well as to users already on the system and being handed off since admission of either kind of user can result in exceeding the system capacity. In addition to limiting the admission of users, steps can be taken to allocate more resources in response to load monitoring. Load monitoring can also be used to determine peak hour activities in CDMA systems. [0014]
  • SUMMARY OF THE INVENTION
  • The present invention is directed to a method and apparatus for monitoring the load on a CDMA communication system having a base station and a plurality of users. A measure of voice activity in the communication system is determined, and a current value of frequency reuse efficiency equal to an initial value of frequency reuse efficiency is provided. A power determination is made according to the determined voice activity and the current value of frequency reuse efficiency. The current value of frequency reuse efficiency is updated using the power determination to provide a new current value of frequency reuse efficiency. The power determination and the update of the frequency reuse efficiency are iteratively repeated until convergence to provide a converged value of frequency reuse efficiency. The load on the communication system is then determined in accordance with the converged frequency reuse efficiency value. [0015]
  • In one embodiment, after the load on the communication system is determined, the admission of new users to the communication system is controlled using the determined load value, e.g., admission of new users is denied when the load is above a threshold. Additionally, load values calculated in accordance with the present invention can be stored in order to collect peak hour activities relating to the communication system.[0016]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein: [0017]
  • FIG. 1 shows a high level overview of the system of the present invention; [0018]
  • FIGS. 2A and 2B show graphical representations of possible loadings of a CDMA communication system; [0019]
  • FIG. 3 shows a flow diagram of the method of the present invention; and [0020]
  • FIG. 4 is a block diagram showing the components of an exemplary base station used for implementing the position tracking system of the present invention.[0021]
  • DETAILED DESCRIPTION OF THE INVENTION
  • Referring now to FIG. 1, there is shown an overview of [0022] communication system 9 of the present invention. Communication system 9 provides real time monitoring and management of system loading. Base station 4 of communication system 9 is in wireless communication with mobile stations 1A-1D by way of antenna 2. Mobile stations 1A-1D can be power controlled CDMA cellular telephones as well known in the art. Base station 4 is also in communication with system management center 5 which can contain any personnel and network computers required to perform any monitoring or management functions required within base station 4. Base station 4 and system management center 5 can communicate by any method known in the art.
  • In normal operation of [0023] system 9, mobile stations 1A-1D periodically communicate with base station 4, either to originate a call, receive a call, or to send or receive various overhead messages to or from base station 4. During peak usage hours, such as during the middle of the day, all four mobile stations 1A-1D may be in simultaneous communication with base station 4, thereby increasing system loading and interference on the reverse link. Conversely, during non-peak usage hours, such as during the middle of the night, fewer mobile stations 1A-1D may be in communication with base station 4 at any time, thereby decreasing system loading. It will be understood that there may be fewer or many more than four mobile stations 1A-1D simultaneously communicating with base station 4 depending on the capacity of base station 4.
  • In practicing the system and method of the present invention, the system loading and the frequency reuse efficiency in an active CDMA communication system can be monitored. Information about system loading can then be used by a base station controller, a base station, or any other control device to control loading, establish admission policy to the system and collect peak hour activities. In order to obtain this information and perform these operations, traffic channel SNR information available to a cell site modem is used. In particular, the energy per bit (E[0024] b) to noise power spectral density (Nt) of a reverse traffic channel i in a sector k of the CDMA system is used. This quantity is given by ( E b N t ) i = x i = ( W / R i ) C i N o W + 1 F k j i N v j C j ( 1 ) x i [ N o W + 1 F k j i N v j C j ] = W R i C i ( 2 ) x i [ N o W + 1 F k j = 1 N v j C j - 1 F k v i C i ) ] = W R i C i ( 3 ) x i [ N o W + 1 F k j = 1 N v j C j ] = W R i C i + 1 F k x i v i C i ( 4 ) C i = x i W / R i + 1 F k v i x i [ N o W + 1 F k j = 1 N v j C j ] ( 5 )
    Figure US20020061006A1-20020523-M00001
  • where N[0025] oW represents the thermal/background noise, Ci is the power received at the antenna connector of the base station from user i, vi is the average voice activity of user i which the base already knows, N is the number of simultaneous users in the sector, W is the bandwidth of the CDMA waveform, Ri is the data rate of user i, and Fk is the frequency reuse efficiency of sector k.
  • As explained below, the voice activity v[0026] i is calculated over N frames based on the data rate(s) used for transmission of traffic information from the mobile station during the frames. For example, in a typical CDMA system frames may be transmitted to the base station using one of four rates (i.e., full rate, ½ rate, ¼ rate and ⅛ rate). In such systems, prior to transmission, the mobile station interleaver output stream is time gated to allow transmission of certain interleaver output symbols and deletion of others. The duty cycle of the transmission gate varies with the transmit data rate. When the transmit rate is 1 (full-rate), the transmission gate allows all interleave output symbols to be transmitted. When the transmit rate is ½, the transmission gate allows one-half of the interleaver output symbols to be transmitted, and so forth. For a given time interval that includes N1 frames of rate 1, N2 frames of rate ½, N3 frames of rate ¼, and N4 frames of rate ⅛, where N=N1+N2+N3+N4, the voice activity factor (v) averaged over N frames is calculated as follows: v = N 1 N + 1 2 N 2 N + 1 4 N 3 N + 1 8 N 4 N ( 6 )
    Figure US20020061006A1-20020523-M00002
  • The frequency reuse efficiency F[0027] k mentioned above can be represented as follows: F k = Interference from units within the cell Total Interference from all cells ( 7 )
    Figure US20020061006A1-20020523-M00003
  • Multiplying by v[0028] i and summing Equation (5) over all values of i i = 1 N v i C i = [ N o W + 1 F k j = 1 N v j C j ] i = 1 N v i x i W / R i + 1 F k v i x i ( 8 )
    Figure US20020061006A1-20020523-M00004
  • Equation (8) can be rewritten as [0029] 1 F k i = 1 N v i C i [ N o W + 1 F k j = 1 N v j C j ] = 1 F k i = 1 N v i x i W / R i + 1 F k v i x i ( 9 )
    Figure US20020061006A1-20020523-M00005
  • The left side of Equation (9) represents the ratio of the CDMA power to the total received power. This ratio is defined as the percentage of loading of the CDMA communication system. On the right side of Equation (9), the frequency reuse efficiency F[0030] k is an estimated value. All of the other values of the right side of Equation (9) are known. Thus it is possible to calculate the percentage of loading of the communication system if a value of the frequency reuse efficiency Fk is obtained.
  • Referring now to FIGS. 2A, 2B, there are shown [0031] graphical representations 10, 12. Graphical representations 10, 12 indicate possible loadings of CDMA sectors. In the CDMA sector represented by graphical representation 10, approximately fifty percent of the received power is CDMA power and approximately fifty percent of the total received power is noise (NoW). In the CDMA sector represented by graphical representation 12, approximately seventy-five percent of the total received power is CDMA power and approximately twenty-five percent of the received power is noise (NoW). Thus the percentages of loading of the sectors of FIGS. 2A, 2B are fifty and seventy-five, respectively.
  • Referring now to FIG. 3, there is shown a flow chart representation of communication [0032] system control method 50 of the present invention for load monitoring and determining frequency reuse efficiency within communication system 9. Method 50 is preferably implemented in software on a controller coupled to the cell site modem associated with the sector/cell under consideration.
  • When monitoring reverse RF link loading according to communication [0033] system control method 50, a CDMA communication system can estimate the voice activity vi for each reverse traffic channel i in a sector k as shown in block 52. It is known to those skilled in the art that the reverse traffic channel includes power control groups for transmitting power control information from a mobile station to the base station. At the end of each power control group a decision can be made by a channel element processor in the base station whether the transmitter of mobile i is on or off during the period of the power control group. This information can be used to determine the voice activity on traffic channel i as shown in equation (6).
  • For each reverse traffic channel in the sector, [0034] communication system 9 estimates the energy per bit to noise power spectral density xi=(Eb/Nt)i as shown in block 54. Depending on the implementation, either an average or instantaneous estimate of the energy per bit to noise power spectral density xi=(Eb/Nt)i may be used. The ratio of the energy per bit to the noise power spectral density of CDMA communication systems can be determined in different ways. One way is to use instantaneous values of Eb/Nt. Another involves using set point values of Eb/Nt. In general, the instantaneous values of Eb/Nt are obtained from the base station controller and the set point values are obtained from a selector. If the instantaneous values are used, the base station processor can calculate the instantaneous loading using Equation (9) and pass the loading information to an admission control processor. If set point values from the selector are used, the base station controller can use Equation (9) to calculate the load corresponding to the determined set points. It will be understood that the value of the reverse link energy per bit to noise power spectral density required to sustain a specific frame error rate on the reverse traffic channel of user i can be represented as (Eb/Nt)i.
  • The total received power [0035] P t = N o W + 1 F k j 1 N v j C j (10A)
    Figure US20020061006A1-20020523-M00006
  • is then measured as shown in [0036] block 56. This quantity is readily available from the automatic gain control circuit of a conventional base station, or alternatively may be measured in other ways known in the art. As shown in block 58, Equation (8) is used along with Equation 10(A) to calculate the CDMA power of sector k. This calculation is performed in accordance with equation 10(B) using a current value, which is an estimated initial value of frequency reuse efficiency Fk(0). A good initial value of Fk(0) can be 0.66. P cdma ( 0 ) = i = 1 N v i C i = P t i = 1 N v i x i W / R i + 1 F k ( 0 ) v i x i (10B)
    Figure US20020061006A1-20020523-M00007
  • The frequency reuse efficiency is updated to produce a new current value as shown in [0037] block 60. During each iteration the current value of frequency reuse efficiency is updated to provide a new current value of frequency reuse efficiency. The new current value is calculated as follows: F k ( 1 ) = P cdma ( 0 ) P t - N o W ( 11 )
    Figure US20020061006A1-20020523-M00008
  • The iteration of [0038] blocks 56, 58, 60 continues until the estimate of Fk converges as determined in decision block 62 according to the following: P cdma ( n ) = i = 1 N v i C i = P t i = 1 N v i x i W / R i + 1 F k ( n ) v i x i ( 12 ) F k ( n + 1 ) = P cdma ( n ) P t - N o W ( 13 )
    Figure US20020061006A1-20020523-M00009
  • The final value of the frequency reuse efficiency is thus determined according to [0039] decision 62. As shown in block 64 the sector loading is then calculated using the frequency reuse efficiency in the manner set forth in Equation (9). The operations of block 64 can be performed, for example, when two consecutive calculations of frequency reuse efficiency produce the same result within the precision of the processor performing the calculations or when two consecutive calculations of frequency reuse efficiency are within a predetermined threshold of each other. The CDMA communication system can then be controlled, for example, by a base station controller according to the system loading, the frequency reuse efficiency, or any other value obtained using communication system control method 50 as shown in block 66. For example, the admission of new users to the communication system can be controlled according to the system loading. Alternatively, the system loading can be monitored in order collect information reflecting peak hour activities at a base station.
  • Referring now to FIG. 4, there is shown a block diagram of the components of an exemplary [0040] CDMA base station 400 used for implementing the load monitoring system of the present invention. At the base station, two receiver systems are utilized with each having a separate antenna and analog receiver for diversity reception. In each of the receiver systems, the signals are processed identically until the signals undergo a diversity combination process. The elements within the dashed lines correspond to elements corresponding to the communications between the base station and one mobile station. Referring still to FIG. 4, the first receiver system is comprised of antenna 460, analog receiver 462, searcher receiver 464 and digital data receivers 466 and 468. The second receiver system includes antenna 470, analog receiver 472, searcher receiver 474 and digital data receiver 476. Cell-site control processor 478 is used for signal processing and control. Among other things, cell site processor 478 monitors the signals sent to and received from a mobile station and uses this information to perform the load monitoring calculations described above. Thus, the system of FIG. 3 is preferably implemented in software on cell site processor 478.
  • Both receiver systems are coupled to diversity combiner and [0041] decoder circuitry 480. A digital link 482 is used to communicate signals from and to a base station controller or data router under the control of control processor 478. Signals received on antenna 460 are provided to analog receiver 462, where the signals are amplified, frequency translated and digitized in a process identical to that described in connection with the mobile station analog receiver. The output from the analog receiver 462 is provided to digital data receivers 466 and 468 and searcher receiver 464. The second receiver system (i.e., analog receiver 472, searcher receiver 474 and digital data receiver 476) processes the received signals in a manner similar to the first receiver system. The outputs of the digital data receivers 466, 476 are provided to diversity combiner and decoder circuitry 480, which processes the signals in accordance with a decoding algorithm. Details concerning the operation of the first and second receiver systems and the diversity combiner and decoder 980 are described in U.S. Pat. No. 5,101,501 entitled “Method and Apparatus for Providing A Soft Handoff In Communications In A CDMA Cellular Telephone System”, incorporated above. Signals for transmission to mobile units are provided to a transmit modulator 484 under the control of processor 478. Transmit modulator 484 modulates the data for transmission to the intended recipient mobile station.
  • The previous description of the preferred embodiments is provided to enable any person skilled in the art to make and use the present invention. The various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.[0042]

Claims (12)

What is claimed is:
1. A digital signal processing apparatus to estimate loading in a spread spectrum wireless communication system, comprising the steps of:
receive circuitry; and
processor communicatively coupled to the receive circuitry, the processor capable of executing commands and data to estimate loading of the system by:
determining frequency reuse of the system; and
determining loading of the system as a function of the frequency reuse.
2. The apparatus of claim 1, wherein determining the frequency reuse of the system, comprises determining a power associated with voice activity to determine the frequency reuse.
3. The method of claim 2, wherein determining the frequency reuse of the system is an iterative process.
4. The method of claim 3, wherein the frequency reuse Fk(n+1) is calculated as:
F k ( n + 1 ) = P ( n ) P t - N o W
Figure US20020061006A1-20020523-M00010
wherein Pt is total power received at receive circuitry, P is the power of spread spectrum frames, and NoW represents background noise received at the base station.
5. The apparatus of claim 4, wherein the loading is determined in accordance with the following equation:
L = 1 F k i = 1 N v i x i W / R i + 1 F v i x i
Figure US20020061006A1-20020523-M00011
where Fk is the converged frequency reuse efficiency value, vi corresponds to a voice activity factor, Ri is the data rate of a user of the communication system, and xi is the energy per bit to noise power spectral density of a reverse traffic channel in the communication system.
6. The apparatus of claim 5, wherein the voice activity factor is equal to one indicating a data communication.
7. A digital signal processing apparatus to process communications in a spread spectrum wireless communication system, comprising the steps of:
receive circuitry; and
processor communicatively coupled to the receive circuitry, the processor capable of executing commands and data to estimate loading of the system by:
determining frequency reuse of the system;
determining loading of the system as a function of the frequency reuse; and
determining admission of calls received at the receive circuitry based on the loading.
8. The apparatus of 8, wherein determining admission comprises accepting a new call when the loading is a first value and rejecting a new call when the loading is a second value.
9. The method of claim 8, wherein when the loading the second value, rescheduling the new call.
10. The method of claim 7, wherein the is used to schedule calls within the system.
11. A computer-readable medium, storing:
a first set of instructions for determining frequency reuse of the system;
a second set of instructions for determining loading of the system as a function of the frequency reuse; and
a third set of instructions determining admission of new calls.
12. A system for monitoring the load on a CDMA communication system, comprising:
means for determining frequency reuse of the system;
means for determining loading of the system as a function of the frequency reuse; and
means for determining admission of new calls.
US10/006,075 1999-06-07 2001-12-06 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio Abandoned US20020061006A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/006,075 US20020061006A1 (en) 1999-06-07 2001-12-06 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/327,103 US6356531B1 (en) 1999-06-07 1999-06-07 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio
US10/006,075 US20020061006A1 (en) 1999-06-07 2001-12-06 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/327,103 Continuation US6356531B1 (en) 1999-06-07 1999-06-07 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Publications (1)

Publication Number Publication Date
US20020061006A1 true US20020061006A1 (en) 2002-05-23

Family

ID=23275172

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/327,103 Expired - Lifetime US6356531B1 (en) 1999-06-07 1999-06-07 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio
US10/006,075 Abandoned US20020061006A1 (en) 1999-06-07 2001-12-06 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/327,103 Expired - Lifetime US6356531B1 (en) 1999-06-07 1999-06-07 Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Country Status (15)

Country Link
US (2) US6356531B1 (en)
EP (1) EP1190501B1 (en)
JP (1) JP4405700B2 (en)
KR (1) KR100635690B1 (en)
CN (1) CN1148892C (en)
AT (1) ATE406706T1 (en)
AU (1) AU5469700A (en)
BR (1) BR0011360A (en)
CY (1) CY1109136T1 (en)
DE (1) DE60040069D1 (en)
DK (1) DK1190501T3 (en)
ES (1) ES2311460T3 (en)
HK (1) HK1044425B (en)
PT (1) PT1190501E (en)
WO (1) WO2000076086A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020119783A1 (en) * 2000-12-27 2002-08-29 Yair Bourlas Adaptive call admission control for use in a wireless communication system
US20030202485A1 (en) * 2002-04-30 2003-10-30 Carl Mansfield Terminal assisted scheduling for time coordinated CDMA
US20040132460A1 (en) * 2002-12-20 2004-07-08 Lg Electronics Inc. Method for preventing overload in base station and base station system thereof
EP1587268A1 (en) * 2004-04-14 2005-10-19 Samsung Electronics Co., Ltd. Apparatus and method for controlling transmission power in communication systems using orthogonal frequency division multiple access scheme
US20080195609A1 (en) * 2004-04-22 2008-08-14 Weborama Method and System for Generating a Population Representative of a Set of Users of a Communication Network
US20080205369A1 (en) * 2007-02-23 2008-08-28 Samsung Electronics Co., Ltd. Apparatus and method for power distribution by frequency allocation in multi-frequency allocation broadband wireless communication system
US20090040978A1 (en) * 2007-08-09 2009-02-12 Samsung Electronics Co., Ltd. System and method for using frequency resource in communication system
US8358613B1 (en) * 2009-02-27 2013-01-22 L-3 Communications Corp. Transmitter-directed security for wireless-communications

Families Citing this family (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100294043B1 (en) * 1998-04-14 2001-07-12 윤종용 A method and an apparatus for optimizing forward link power control parameters using lab. test in pcs cdma system
US6356531B1 (en) * 1999-06-07 2002-03-12 Qualcomm Incorporated Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio
CA2308651C (en) * 1999-07-12 2010-04-27 Nortel Networks Corporation A method of controlling base station transmitting power during soft handoff
WO2001095535A1 (en) * 2000-06-09 2001-12-13 Advantest Corporation Apparatus, method, and program for displaying waveform quality of cdma signal, and recorded medium where the program is recorded
KR100387057B1 (en) * 2000-07-04 2003-06-12 삼성전자주식회사 Method and apparatus for determining reverse data rate in mobile communication system
US6584330B1 (en) * 2000-07-18 2003-06-24 Telefonaktiebolaget Lm Ericsson (Publ) Adaptive power management for a node of a cellular telecommunications network
US7227850B2 (en) * 2001-04-04 2007-06-05 Telefonaktiebolaget Lm Ericsson (Publ) Cellular radio communication system with frequency reuse
US6850500B2 (en) 2001-05-15 2005-02-01 Interdigital Technology Corporation Transmission power level estimation
US6963755B2 (en) * 2002-01-09 2005-11-08 Qualcomm, Incorporated Method and apparatus for coherently combining power control commands to initialize communication
US20030223396A1 (en) * 2002-05-31 2003-12-04 Tsai Shiau-He Shawn Method of indicating the forward link serving sector in high data rate CDMA systems
US7136483B2 (en) * 2002-07-24 2006-11-14 Telefonaictiebolaget Lm Ericsson (Publ) Mobile terminal mode control in high data rate CDMA system
US8504054B2 (en) * 2002-09-10 2013-08-06 Qualcomm Incorporated System and method for multilevel scheduling
US7773985B2 (en) * 2003-09-22 2010-08-10 United Parcel Service Of America, Inc. Symbiotic system for testing electromagnetic signal coverage in areas near transport routes
US7660577B2 (en) * 2003-09-22 2010-02-09 United Parcel Service Of America, Inc. Network testing systems and methods
US9585023B2 (en) * 2003-10-30 2017-02-28 Qualcomm Incorporated Layered reuse for a wireless communication system
US8526963B2 (en) * 2003-10-30 2013-09-03 Qualcomm Incorporated Restrictive reuse for a wireless communication system
US8059589B2 (en) * 2004-06-09 2011-11-15 Qualcomm Incorporated Dynamic restrictive reuse scheduler
US8032145B2 (en) 2004-07-23 2011-10-04 Qualcomm Incorporated Restrictive reuse set management algorithm for equal grade of service on FL transmission
US7257406B2 (en) * 2004-07-23 2007-08-14 Qualcomm, Incorporated Restrictive reuse set management
US7548752B2 (en) * 2004-12-22 2009-06-16 Qualcomm Incorporated Feedback to support restrictive reuse
US7580712B2 (en) * 2005-06-03 2009-08-25 Telefonaktiebolaget Lm Ericsson (Publ) Wireless high-speed data network planning tool
US7440730B2 (en) * 2005-06-30 2008-10-21 Intel Corporation Device, system and method of multiple transceivers control
US7738422B2 (en) * 2005-08-23 2010-06-15 Alcatel-Lucent Usa Inc. Interference-reducing method of forward link scheduling for wireless networks
CN100421524C (en) * 2005-12-06 2008-09-24 华为技术有限公司 Method for optimizing network performance
US7751823B2 (en) 2006-04-13 2010-07-06 Atc Technologies, Llc Systems and methods for controlling a level of interference to a wireless receiver responsive to an activity factor associated with a wireless transmitter
KR101364569B1 (en) 2007-03-23 2014-02-19 서강대학교산학협력단 Apparatus and method for opportunistic packet scheduling with frequency reuse and quality of service guarantee in wideband wireless access communication system based multi-hop relay
KR101364567B1 (en) 2007-03-23 2014-02-19 서강대학교산학협력단 Apparatus and method for opportunistic packet scheduling in wideband wireless access communication system based multi-hop relay
TW201125416A (en) * 2009-11-13 2011-07-16 Interdigital Patent Holdings Method and apparatus for providing VHT frequency reuse for WLANs
MX2017004062A (en) * 2014-09-29 2017-08-28 Hughes Network Systems Llc Inter-gateway interference management and admission control for a cdma satellite communications system.
CN111225392B (en) * 2018-11-27 2023-12-15 中国移动通信集团辽宁有限公司 Cell load balancing method, device, equipment and computer storage medium

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4901307A (en) * 1986-10-17 1990-02-13 Qualcomm, Inc. Spread spectrum multiple access communication system using satellite or terrestrial repeaters
US5056109A (en) * 1989-11-07 1991-10-08 Qualcomm, Inc. Method and apparatus for controlling transmission power in a cdma cellular mobile telephone system
US5859838A (en) * 1996-07-30 1999-01-12 Qualcomm Incorporated Load monitoring and management in a CDMA wireless communication system
US6278701B1 (en) * 1998-07-10 2001-08-21 Verizon Laboratories Inc. Capacity enhancement for multi-code CDMA with integrated services through quality of services and admission control
US6356531B1 (en) * 1999-06-07 2002-03-12 Qualcomm Incorporated Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5710758A (en) * 1995-09-29 1998-01-20 Qualcomm Incorporated Wireless network planning tool
US6067446A (en) 1996-07-11 2000-05-23 Telefonaktiebolaget Lm Ericsson Power presetting in a radio communication system
FI964707A (en) 1996-11-26 1998-05-27 Nokia Telecommunications Oy Method for load control and radio system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4901307A (en) * 1986-10-17 1990-02-13 Qualcomm, Inc. Spread spectrum multiple access communication system using satellite or terrestrial repeaters
US5056109A (en) * 1989-11-07 1991-10-08 Qualcomm, Inc. Method and apparatus for controlling transmission power in a cdma cellular mobile telephone system
US5859838A (en) * 1996-07-30 1999-01-12 Qualcomm Incorporated Load monitoring and management in a CDMA wireless communication system
US6278701B1 (en) * 1998-07-10 2001-08-21 Verizon Laboratories Inc. Capacity enhancement for multi-code CDMA with integrated services through quality of services and admission control
US6356531B1 (en) * 1999-06-07 2002-03-12 Qualcomm Incorporated Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090185532A1 (en) * 2000-12-27 2009-07-23 Wi-Lan, Inc. Adaptive call admission control for use in a wireless communication system
US7529204B2 (en) 2000-12-27 2009-05-05 Wi-Lan, Inc. Adaptive call admission control for use in a wireless communication system
US8537757B2 (en) 2000-12-27 2013-09-17 Wi-Lan, Inc. Adaptive call admission control for use in a wireless communication system
US8213359B2 (en) 2000-12-27 2012-07-03 Wi-Lan, Inc. Adaptive call admission control for use in a wireless communication system
US20020119783A1 (en) * 2000-12-27 2002-08-29 Yair Bourlas Adaptive call admission control for use in a wireless communication system
US20060126549A1 (en) * 2000-12-27 2006-06-15 Yair Bourlas Adaptive call admission control for use in a wireless communication system
US20070165562A1 (en) * 2000-12-27 2007-07-19 Yair Bourlas Adaptive call admission control for use in a wireless communication system
US7289467B2 (en) * 2000-12-27 2007-10-30 Wi-Lan Inc. Adaptive call control for use in a wireless communication system
US7023798B2 (en) * 2000-12-27 2006-04-04 Wi-Lan, Inc. Adaptive call admission control for use in a wireless communication system
US20030202485A1 (en) * 2002-04-30 2003-10-30 Carl Mansfield Terminal assisted scheduling for time coordinated CDMA
US7177293B2 (en) * 2002-04-30 2007-02-13 Intel Corporation Terminal assisted scheduling for time coordinated CDMA
US20040132460A1 (en) * 2002-12-20 2004-07-08 Lg Electronics Inc. Method for preventing overload in base station and base station system thereof
US20060234715A1 (en) * 2004-04-14 2006-10-19 Samsung Electronics Co., Ltd. Apparatus and method for controlling transmission power in communication systems using orthogonal frequency division multiple access scheme
EP1587268A1 (en) * 2004-04-14 2005-10-19 Samsung Electronics Co., Ltd. Apparatus and method for controlling transmission power in communication systems using orthogonal frequency division multiple access scheme
US7412242B2 (en) 2004-04-14 2008-08-12 Samsung Electronics Co., Ltd Apparatus and method for controlling transmission power in communication systems using orthogonal frequency division multiple access scheme
US20080195609A1 (en) * 2004-04-22 2008-08-14 Weborama Method and System for Generating a Population Representative of a Set of Users of a Communication Network
US20080205369A1 (en) * 2007-02-23 2008-08-28 Samsung Electronics Co., Ltd. Apparatus and method for power distribution by frequency allocation in multi-frequency allocation broadband wireless communication system
US8244292B2 (en) * 2007-02-23 2012-08-14 Samsung Electronics Co., Ltd Apparatus and method for power distribution by frequency allocation in multi-frequency allocation broadband wireless communication system
US20090040978A1 (en) * 2007-08-09 2009-02-12 Samsung Electronics Co., Ltd. System and method for using frequency resource in communication system
US8204012B2 (en) * 2007-08-09 2012-06-19 Samsung Electronics Co., Ltd System and method for using frequency resource in communication system
US8358613B1 (en) * 2009-02-27 2013-01-22 L-3 Communications Corp. Transmitter-directed security for wireless-communications

Also Published As

Publication number Publication date
WO2000076086A9 (en) 2002-06-27
CN1354920A (en) 2002-06-19
CN1148892C (en) 2004-05-05
DE60040069D1 (en) 2008-10-09
ATE406706T1 (en) 2008-09-15
JP2003501940A (en) 2003-01-14
CY1109136T1 (en) 2014-07-02
KR100635690B1 (en) 2006-10-17
KR20020008219A (en) 2002-01-29
WO2000076086A1 (en) 2000-12-14
BR0011360A (en) 2002-04-30
PT1190501E (en) 2008-11-17
AU5469700A (en) 2000-12-28
ES2311460T3 (en) 2009-02-16
HK1044425B (en) 2005-03-04
HK1044425A1 (en) 2002-10-18
JP4405700B2 (en) 2010-01-27
US6356531B1 (en) 2002-03-12
DK1190501T3 (en) 2008-12-15
EP1190501A1 (en) 2002-03-27
EP1190501B1 (en) 2008-08-27

Similar Documents

Publication Publication Date Title
US6356531B1 (en) Monitoring of CDMA load and frequency reuse based on reverse link signal-to-noise ratio
EP0948869B1 (en) Load monitoring and management in a cdma wireless communication system
EP1168689B1 (en) Method of detecting and calculating external jammer signal power in communication systems
KR100752085B1 (en) Closed loop resource allocation in a high speed wireless communications network
US5697053A (en) Method of power control and cell site selection
US6628958B1 (en) Method for adjusting the transmit power level during soft handoff in wireless communication systems
HU216926B (en) Transceiver and method for controlling power of incoming spread spectrum signals at the transceivers
HU215857B (en) Method system, apparatus for controlling power of signal in a cdma communication system
US6628637B1 (en) Spread-spectrum carrier transmission power control in wireless telecommunications systems
US6952568B2 (en) Tracking power levels in a wireless telecommunications network
JP2000224106A (en) Open loop power control for radio mobile station
CA2313554A1 (en) Method for initiating call blocking
EP1195920B1 (en) Method of initial transmission power determination
US7085580B1 (en) Aggregate power measurement
JP2005535177A (en) Equalization of the signal-to-interference ratio of several different physical channels that support coded synthesis transport channels
Kandala et al. Integrated voice and video services in microcellular CDMA systems—downlink power-based call admission
Baiocchi et al. Improving the erlang capacity of a CDMA cellular network under bursty user mobility
Suwa et al. Radio link design and reverse link capacity on microcellular DS‐CDMA wideband transmission systems
MXPA99001093A (en) Load monitoring and management in a cdma wireless communication system

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION