CN101322326A - Method and device for controlling base station transmission power - Google Patents

Abstract

Methods and apparatus are described where loading information regarding loading conditions at a neighboring base station is received at a first base station and then communicated, e.g., broadcast, by the first base station to mobiles within the cell in which the first base station is located. Since the neighbor base station's loading information is being communicated to a mobile currently connected to the first base station via a reliable communications channel of the first base station, the mobile can be expected to be able to reliably recover loading factor information corresponding to not only the first base station but to the neighboring base station. By utilizing such loading factor information, the mobile can generate an improved uplink interference report. The first base station receives such interference reports from wireless terminals in its cell, facilitating efficient resource allocation and interference control.

Description

Method and device for controlling base station transmission power

Claiming priority under 35 U.S.C. §119

This application is a continuation-in-part of U.S. 11/251,069, filed October 14, 2005, a continuation-in-part of U.S. Patent Application 11/302,729, filed December 14, 2005, filed July 14, 2006 continuation-in-part of U.S. Patent Application 11/486,714, and continuation-in-part of U.S. Application 11/487,017, filed July 14, 2006, each of which is expressly incorporated herein by reference .

technical field

The present invention relates to wireless communication systems and, more particularly, the present invention relates to power control in wireless communication systems.

Background technique

In a wireless communication system comprising multiple base stations where at least some of the base stations use the same radio resource, e.g. spectrum, downlink transmissions from one base station may interfere with other base stations (e.g. neighboring base stations) using the same spectrum downlink transmission. Downlink traffic channel load conditions at a particular base station attachment point typically vary over time with a number of factors including: number of users, type of users, type of application in use, amount of data to be communicated, degree of fault tolerance, latency Timing requirements, channel conditions, error rates, and location of wireless terminals. Varying the transmit power level of a traffic channel segment can affect the information data rate achievable by a particular wireless terminal, but also changes the view from the perspective of other wireless terminals connected to another base station (such as a neighboring base station) using the same spectrum. Interference levels of other wireless terminals at different base station connection points.

By using a fixed downlink transmit power budget for each base station attachment point, the overall downlink interference in the system can be controlled. The power associated with different subchannels within a downlink traffic channel can vary with the overall downlink power budget kept at a fixed level. This approach tends to limit the overall disturbance in the system, but cannot take advantage of different system load conditions to optimize throughput.

It is advantageous if a base station is not limited to a single downlink power budget but can vary its downlink transmission power budget in response to changing load conditions at itself or at neighboring base stations. It is beneficial if neighboring base stations exchange load information, thus allowing the base stations to make timely decisions about downlink transmission power levels. Furthermore, it is beneficial if the power budget decision for a particular base station is performed at the base station, since the base station has relevant information readily available, such as current load conditions, current channel conditions, user profiles, detected changes, In-progress application, thus facilitating quick notification response to changing conditions.

Contents of the invention

Various embodiments are directed to methods and apparatus for communicating, collecting, measuring, reporting, and/or using information that may be used for interference control purposes, load management, and/or dynamically changing base station downlink power budgets.

According to various embodiments, the base station receives load information indicative of the load of other base stations, such as neighboring base stations, and the base station determines a downlink transmission power budget based on the received load factor information. For example, a base station may reduce the current power budget dedicated to downlink traffic channel segments in response to detecting an increase in the load of neighboring base stations. The base station may increase the current power budget dedicated to the downlink traffic channel segment in response to detecting a decrease in the load of neighboring base stations. Accordingly, the base stations operate in a cooperative manner with reduced power output, in at least some cases where the load of neighboring base stations increases, thereby reducing interference to base stations with increased load. This is in sharp contrast to systems that may attempt to increase power output in response to increased loading of neighboring base stations to overcome increased interference generated by neighboring base stations with increased traffic load. The described method and apparatus are particularly suitable for use in a communication system comprising a plurality of base stations which may interfere with each other. This is because in a wireless communication system including multiple base stations, downlink transmissions from one base station create interference with other base stations (eg, neighboring base stations) using the same frequency spectrum. The base station may make trade-off decisions regarding the downlink power budget (eg, for downlink traffic channels) taking into account possible alternative transmit power levels, estimated interference levels, and/or possible alternative data rates.

An exemplary method of operating a first base station according to various embodiments includes: receiving second base station loading factor information indicative of a loading of a second base station connection point corresponding to a second base station; and based on said received second base station loading factor information to determine the downlink transmit power budget. An exemplary base station according to various embodiments comprises: an interface for receiving a signal conveying base station loading factor information indicative of a loading of at least one base station attachment point corresponding to at least one other base station; a loading factor information recovery module for Loading factor information corresponding to at least one other base station is recovered from said received signal; and downlink transmission power budget determination means, wherein said downlink transmission power budget determination means is based on said at least one other base station The recovered loading factor information is used to determine the downlink transmission power budget of the connection point of the base station.

While various embodiments have been discussed in the summary above, it should be understood that not all embodiments need to include the same features, and that some of the features described above are not required but may be desired in some embodiments. Numerous additional features, embodiments and benefits of the invention are discussed in the detailed description below.

Description of drawings

1 is a diagram of an exemplary wireless communication system implemented in accordance with various embodiments.

2 is a diagram of an exemplary base station in accordance with various embodiments.

FIG. 3 is a diagram of an exemplary wireless terminal in accordance with various embodiments.

4 is a diagram of a flowchart of an exemplary method of operating a first base station in a multiple access wireless communication system comprising a plurality of base stations according to various embodiments.

5 is a diagram of a flowchart of an exemplary method of operating a first base station in a multiple access wireless communication system comprising a plurality of base stations according to various embodiments.

Figure 6 is a diagram of a flowchart 600 of an exemplary method of operating a first base station in a multiple access wireless communication system comprising a plurality of base stations in accordance with various embodiments.

7 is a diagram for explaining features of various embodiments in which a base station in a wireless communication system including a plurality of base stations receives load factor information corresponding to another base station and determines based on the received base station load factor information Downlink transmit power budget.

8 is a diagram for explaining features of various embodiments in which a base station in a wireless communication system including a plurality of base stations receives load factor information corresponding to another base station and determines based on the received base station load factor information Downlink transmit power budget.

9 is a diagram for explaining features of various embodiments in which a base station in a wireless communication system including a plurality of base stations receives loading factor information corresponding to another base station and determines downlink transmission based on the base station loading factor information power budget.

FIG. 10 , comprising the combination of FIG. 10A and FIG. 10B , is a diagram of a flowchart of an exemplary method of operating a base station in accordance with various embodiments.

Detailed ways

1 is a diagram of an exemplary wireless communication system 100, such as a multiple access OFDM wireless communication system, according to various embodiments. The exemplary wireless communication system 100 includes a plurality of base stations (base station 1102, . . . , base station M 104) and a network node 110. Each base station (102, ..., 104) includes at least one base station attachment point. A base station (102, ..., 104) can comprise one or more sectors and utilize one or more carriers. For example, in some embodiments of some base stations, a base station attachment point corresponds to a cell and carrier combination. In some embodiments, the base station attachment points of some base stations correspond to combinations of cells, sectors and carriers. Network node 110 is coupled to (base station 1102, base station M 104) via network links (120, 122), respectively. Network node 110 is also coupled to other network nodes and/or the Internet via network link 124 . The network links 120, 122, 124 are, for example, fiber optic links, wired links, and/or wireless links. Each base station (base station 1102, base station M 104) has a corresponding wireless coverage area (cell 1106, cell M 108), respectively.

Communication system 100 also includes a plurality of wireless terminal sets, such as mobile nodes, that are movable throughout the system and connect to base stations within the coverage areas of which wireless terminal sets are currently located. Wireless terminal sets (WT 1112, ..., WT N 114) currently located in cell 1106 are coupled to base station 1102 via wireless links (126, ..., 128), respectively. Wireless terminals (WT 1' 116, ..., WT N' 118') currently located in cell M 108 are coupled to base station M 104 via wireless links (130, ..., 132), respectively.

At least some of the base stations in system 100 consider load information from other base stations (e.g., neighboring base stations) in addition to their own load, and adjust their downlink transmissions, e.g., dynamically, based on the loading of other base stations (e.g., neighboring base stations) power budget. In some embodiments, the base station makes its own independent determination of its downlink power budget corresponding to one of its base station connection points, but utilizes the received load of other base stations (e.g. neighboring base stations) in the vicinity of the local area information to make the determination.

2 is a diagram of an exemplary base station 200 implemented in accordance with various embodiments. The exemplary base station 200 may be any one of the base stations in FIG. 1 or FIG. 4 or FIG. 5 or FIG. 6 . Exemplary base station 200 includes a receiver module 202, a transmitter module 204, a processor 206, an I/O interface 208, and a memory 210 coupled together via a bus 212 on which the various elements can exchange data and information with each other.

The receiver module 202 (eg, an OFDM receiver) is coupled to a receive antenna 216 via which the base station 200 receives uplink signals from wireless terminals. In some embodiments, the uplink signal includes base station loading factor information corresponding to other base stations in said communication system, for example, where a wireless terminal connected to base station 200 and another base station (e.g., a neighboring base station) is used as an intermediate station. Repeater.

The transmitter module 204 (eg, an OFDM transmitter) is coupled to a transmit antenna 218 via which the base station 200 transmits downlink signals to wireless terminals. The downlink signal includes a traffic channel signal and a pilot channel signal, wherein the power budget of the traffic channel signal is controlled according to the loading factor information corresponding to other base stations (eg neighboring base stations) and the loading factor information corresponding to the base station 200 .

I/O interface 208 couples base station 200 to the Internet and/or other network nodes, such as neighboring base stations. Loading factor information is exchanged between base station 200 and other base stations (eg, neighboring base stations) via I/O interface 208 . Accordingly, the I/O interface 208 receives a signal conveying base station loading factor information indicative of the loading of at least one base station attachment point corresponding to at least one other base station (eg, a neighboring base station).

Memory 210 includes routines 220 and data/information 222 . Processor 206 (eg, CPU) executes routines 220 and uses data/information 222 in memory 210 to control the operation of base station 220 and implement methods.

Routines 220 include communication routines 224 and base station control routines 226 . Communication routines 224 implement various communication protocols used by base station 200 . Base station control routine 226 includes scheduler 228, pilot channel signaling module 230, traffic channel signaling module 232, loading factor information recovery module 234, downlink transmission power budget determination module 236, loading factor determination module 238, load factor comparison module 240 and load factor tracking module 242 . In some embodiments, at least one of the loading factor comparison module 240 and the loading factor tracking module 242 is included as part of the downlink transmission power budget determination module 236 .

The scheduler 228 schedules wireless terminals to downlink and uplink traffic channel segments. Pilot channel signaling module 230 controls the generation and transmission of pilot channel signals, such as known modulation symbols at predetermined power levels at predetermined locations in the recurring timing and frequency structure. In this exemplary embodiment, the pilot channel signal corresponding to the base station connection point is transmitted at the same transmission power level per tone independent of the downlink loading conditions of base station 200 or neighboring base stations. The traffic channel signaling module 232 controls the generation and transmission of traffic channel segment signals (eg, downlink traffic channel segment signals). For downlink traffic channels, the total power budget associated with the base station 200 connection point is dynamically adjusted in response to determinations by the downlink transmit power budget determination module 236 . Individual subchannels within a downlink traffic channel can, and sometimes do, transmit at different power levels.

The loading factor information recovery module 234 recovers, from the received signal, loading factor information corresponding to base station connection points of other base stations (eg, neighboring base stations). For example, the loading factor information recovery module 234 respectively from the received signals (received BS 2 signal (1) 244, received BS 2 signal (n) 246, received BS N signal (1) 252, The received BS N signal (n) 254) is obtained (recovered BS 2LF(t1) 248, recovered BS 2LF(tn) 250, recovered BS N LF(t1) 256, recovered BS N LF (tn) 258). The loading factor information in various embodiments is about the downlink transmission load of the base station connection point, eg the downlink traffic channel load of the base station connection point.

Downlink transmission power budget determination module 236 determines a downlink transmission power budget for one or more connection points of base station 200 based on recovered loading factor information corresponding to at least one other base station (eg, one other neighboring base station). In various embodiments, the determined power budget is a power budget for a set of downlink communication channels including at least one pilot channel and a data traffic channel. In some such embodiments, a portion of the determined power budget for the pilot channel is independent of loading factor information, and a portion of the power budget corresponding to the data traffic channel is dependent on base station loading of other base stations (e.g., neighboring base stations) factor information and load factor information of the base station 200 . For example, the pilot channel signal may be transmitted at a power level per tone that does not vary with load, while the traffic channel signal transmission power level may vary with the determined loading factor of the base station 200 connection point and the connection points corresponding to neighboring base stations. The received load factor varies. The results of the load factor comparison module 240 may be used as input by the determination module 236 . The determined transmit power budget (time T1 ) 264 and the determined transmit power budget (time Tn) 270 are outputs from the determination module 236 .

For each connection point of the base station 200 , the loading factor determination module 238 determines the loading factor corresponding to the connection point of the base station 200 . Determined base station loading factor (time t1) 260 and determined base station loading factor (time tn) 262 represent outputs of determination module 236 corresponding to the same base station 200 connection point at different times.

The loading factor comparison module 240 compares the determined loading factor corresponding to the connection point of the base station 200 with the recovered loading factor corresponding to the connection point of another base station (eg, a neighboring base station).

In some embodiments, when the load factor comparison module 240 determines that the load of the connection points of other base stations involved in the comparison (such as neighboring base stations) is greater than the load of the connection points of the base station 200, the downlink transmission power budget determination module 236 determining the power budget to correspond to the first value indicative of the budget; and, when the load factor comparison module 240 determines that the load of the connection points of other base stations involved in the comparison (e.g. neighboring base stations) is less than that of the base station 200 The downlink transmission power budget determination module 236 determines the power budget to correspond to a second value indicative of a power budget greater than the power budget indicated by the first value when the connection point is loaded.

In some embodiments, a highly loaded base station sends its loading factor to a neighboring base station, expecting that the base station receiving the loading factor will have a lower load and will reduce its transmission power budget. This in turn will reduce the interference experienced by the highly loaded base station and allow the throughput of the highly loaded base station to be increased.

The loading factor tracking module 242 tracks changes in loading factors of base station connection points (eg, connection points corresponding to base station 200 and connection points corresponding to other base stations (eg, neighboring base stations)). The detected changes identified by the loading factor tracking module 242 are used by the downlink transmission power budget determination module 236 to determine the power budget for the base station connection point of the base station 200 . In some embodiments, the downlink transmission power determination module 236 reduces the current power budget of the connection point of the base station 200 in response to a detected increase in the load of other base stations (e.g., neighboring base stations), and the downlink transmission power determination Module 236 increases the current power budget in response to a detected decrease in loading of other base stations (eg, neighboring base stations). In some embodiments, the downlink transmission power determination module 236 increases the current power budget of the connection point of the base station 200 in response to the detected increase in the load of the connection point of the base station 200, and the downlink transmission power determination Module 236 reduces the current power budget in response to the detected decrease in loading of the connection point of base station 200 .

Data/information 222 includes received signals conveying loading factor information corresponding to a plurality of base stations over time ((received base station 2 signal (1) 244, ..., received base station 2 signal (n) 246) , . . . , (received base station N signal (1) 252, . . . , received base station N signal (n) 254)). In some embodiments, the received signal conveying loading factor information has been conveyed by I/O interface 208 via a backhaul network. In some embodiments, the received signal has been received by receiver 202, eg, where a wireless terminal coupled to two base stations relays the information. The data/information 210 also includes recovered base station 2 loading factor information (recovered BS 2 loading factor (t1) 248, ..., recovered BS 2 loading factor (tn) ) representing base station 2 loading at different times 250), recovered base station N loading factor information representing base station N loading at different times (recovered BSN loading factor (t1) 256, ..., recovered BSN loading factor (tn) 258), and Determined BS 200 loading factor information (determined BS loading factor (t1) 260, ..., determined BS loading factor (tn) 262) representing base station 200 loading at different times.

Data/Information 222 also includes determined downlink power budget information for BS 200 over time (Determined Downlink Transmission Power Budget (T1) 264, ..., Determined Downlink Transmission Power Budget (Tn )270). Determined downlink transmission power budget information 264 includes pilot channel budget information 266 and determined downlink traffic channel budget information (T1) 268, while determined downlink transmission power budget (Tn) 270 includes Pilot channel power budget information 266 and determined downlink traffic channel power budget (Tn) 272 . In this exemplary embodiment, the pilot channel signal transmission power level does not vary with loading conditions; however, the downlink traffic channel power budget can (and sometimes does) vary with, for example, neighboring base stations and/or base station 200 load conditions and/or changes in load conditions.

Data/information 222 also includes comparison criteria for modified power budget 274, current number of users 276, backlog downlink traffic volume 278, and downlink channel condition information. The comparison criteria 274 for modifying the power budget include predetermined thresholds used by the loading factor comparison module 240 , the loading factor tracking module 242 , and/or the downlink transmit power budget determination module 236 . The current number of users 276 includes, for example, information corresponding to the number of currently registered users, the number of active users, and/or the number of on-state users at the base station 200 connection point. Backlog downlink traffic channel traffic 278 includes, for example, information identifying the number of MAC frames of downlink traffic to be transmitted corresponding to each current user of base station 200, and identifying composite pending transmissions corresponding to registered users. Information about the number of MAC frames of the downlink traffic. The downlink channel condition information 280 includes, for example, channel condition measurement information corresponding to the current user of the base station 200, such as signal-to-noise ratio measurement information and/or signal-to-interference ratio measurement information. At least some of the current number of users information 276, the backlog of downlink traffic channel information 278, and the downlink channel condition information 280 are used by the loading factor determination module 238 to determine a loading factor corresponding to the base station 200 attachment point.

Figure 3 is a diagram of an exemplary wireless terminal set 300 (eg, mobile node) according to various embodiments. The exemplary wireless terminal 300 can be any one of the exemplary wireless terminals in FIG. 1 or FIG. 4 or FIG. 5 or FIG. 6 . The exemplary wireless terminal 300 includes a first receiver module 302, a first transmitter module 304, a processor 306, and an I/O device 308 coupled together via a bus 312 on which various components can exchange data information with each other. and memory 310 . In some embodiments, the wireless terminal 300 also includes a second receiver module 318 and a second transmitter module 320 also coupled to the bus 312 .

A first receiver module 302 (eg, an OFDM receiver) is coupled to a receive antenna 314 via which the wireless terminal 300 receives downlink signals from a base station. The downlink signal includes an assignment signal (such as a downlink traffic channel segment assignment signal), a downlink traffic channel segment signal, a request for a wireless terminal to relay base station load information, a request for a wireless terminal to relay base station load information and/or commands for base station attachment point load information.

The first transmitter module 304 (eg, an OFDM transmitter) is coupled to a transmit antenna 316 via which the wireless terminal 300 transmits uplink signals to the base station. In some embodiments, the receiver module 302 uses the same antenna as the transmitter module 304, for example in combination with a duplex module. Uplink signals include dedicated control channel reports (eg, SNR reports), uplink traffic channel segment signals, access signals, power control signals, timing control signals, and handover signals. The uplink signals also include messages conveying loading factor information corresponding to a base station attachment point, eg, where the wireless terminal acts as a repeater between two adjacent base stations.

A second receiver module 318 (eg, an OFDM receiver) is coupled to a receive antenna 322 via which the wireless terminal 300 receives downlink signals from base stations. The downlink signal includes an assignment signal (such as a downlink traffic channel segment assignment signal), a downlink traffic channel segment signal, a request for a wireless terminal to relay base station load information, a request for a wireless terminal to relay base station load information and/or commands for base station attachment point load information.

A second transmitter module 320 (eg, an OFDM transmitter) is coupled to a transmit antenna 324 via which the wireless terminal 300 transmits uplink signals to the base station. In some embodiments, the receiver module 318 uses the same antenna as the transmitter module 324, eg, in combination with a duplex module. Uplink signals include dedicated control channel reports (eg, SNR reports), uplink traffic channel segment signals, access signals, power control signals, timing control signals, and handover signals. Uplink signals also include messages conveying loading information (eg, downlink loading factors) corresponding to a point of attachment of a base station, eg, where the wireless terminal acts as a repeater between two base stations.

I/O devices 308 (eg, keypads, keyboards, microphones, switches, displays, speakers, etc.) allow a user of WT 300 to input data/information and access output data/information. The input device 308 also allows the user to control at least some functions of the wireless terminal, such as initiating a communication session with a peer node.

Memory 310 includes routines 326 and data/information 328 . Processor 306 (eg, CPU) executes routines 326 and uses data/information 328 in memory 310 to control the operation of wireless terminal 300 and implement method steps. Routine 326 includes communication routine 330 and base station control routine 332 . The communication routine 330 implements various communication protocols used by the wireless terminal 300 . Base station control routine 332 includes a loading factor relay request/command monitor module 334 , a loading factor recovery module 336 , and a loading factor relay module 338 .

The loading factor request/command monitoring module 334 monitors received downlink signaling for requests and/or commands directed to the wireless terminal set 300 that instruct the wireless terminal set 300 to receive from the first base station a corresponding base station loading factor information (eg, downlink traffic channel base station loading information) at one or more connection points and relay the loading factor information to a second base station. In some embodiments, when the wireless terminal set 300 is in a wireless terminal set operating mode (wherein the wireless terminal set simultaneously supports two communication links to two different base station attachment points), the load factor relay is used Request/Command Monitoring Module 334 . For example, WT 300 may be in a multi-connection mode of operation that is currently coupled to a first base station via a receiver/transmitter module pair (302/304) and is simultaneously coupled to a base station via a receiver/transmitter module pair (318/320) The second base station, and the monitoring module 334 detects a signal requesting or ordering the wireless terminal 300 to transmit downlink load information about the connection point of the first base station to the second base station. In some embodiments, if the wireless terminal receives a request to transmit loading factor information, and the wireless terminal is not in multi-connection mode, then the wireless terminal may transition to Multiple connection mode.

The loading factor recovery module 336 , responsive to the request or command detected by the module 334 , recovers loading information, eg, downlink base station connection point loading information, from the received downlink signal. The loading factor relay module 338 in response to the loading factor recovery module 336 generates a message conveying the recovered loading factor information, which is communicated to another base station (eg, a neighboring base station) via uplink signaling. The loading factor relay module 336 also controls the transmission of the generated relay messages.

Data/information 328 includes received requests/commands for relay loading factor information 340, received base station loading factor information 342, generated base station loading factor message information 344, system base station information 346, and wireless terminal operating mode information 348 . Received request/command to relay base station loading factor information 340 includes a received request and/or command for wireless terminal set 300 to act as a repeater and communicate loading factor information between base stations. In some embodiments, the request identifies a destination base station. In some embodiments, the wireless terminal uses the stored system base station information 346 to determine related destination base stations (eg, neighboring base stations) that may be affected (eg, interfered) by downlink signaling from the source base station connection point. Received base station loading factor information 342 (eg, base station attachment point loading factors corresponding to downlink traffic channel loads) is an output of recovery module 336 and an input of loading factor relay module 338 . The generated base station loading factor relay message is an output of the loading factor relay module 338 and is used as an input to a wireless transmitter module (eg, module 304 or module 320). The system base station information 346 includes information corresponding to a plurality of base stations in the wireless communication system (base station 1 information 350, ..., base station n information 352). Base station 1 information 350 includes information corresponding to each of the connection points of base station 1, such as downlink carrier information, downlink tone block information, uplink carrier information, uplink carrier information, channel structure information , tone hopping information, power level information, message structure information, cycle timing structure information, etc. WT mode of operation information 348 includes information identifying whether the wireless terminal set 300 is in a single-connection mode of operation or in a multi-connection mode of operation.

4 is a diagram of a flowchart 400 of an exemplary method of operating a first base station in a multiple access wireless communication system comprising a plurality of base stations in accordance with various embodiments. Each base station in the exemplary communication system includes at least one base station attachment point through which wireless terminals (eg, mobile nodes) in the vicinity of the base station can connect to the network. A base station may include one or more sectors. In this exemplary embodiment, a base station attachment point corresponds to a base station sector, uplink carrier, uplink OFDM tone block, downlink carrier, and downlink OFDM tone block.

Operation begins at step 402 where a first base station is powered on and initialized, and proceeds to step 404 . In step 404, the first base station receives second base station loading factor information indicative of a load of a second base station connection point corresponding to the second base station. The second base station can be, and sometimes is, adjacent to the first base station. Exemplary load information for a base station includes the number of connected active terminal sets, the quality of service (QoS) profile of the terminal sets (e.g., the number of high QoS value terminal sets versus the number of low QoS value terminal sets), QoS profile of the traffic associated with the terminal set (e.g. volume of audio or video traffic versus best effort data traffic) and radio link resources required to support the traffic required by the connected active terminal set ( For example, Power vs. Bandwidth). For example, when a base station serves increased voice traffic, the load may increase. Furthermore, even if the base station serves the same amount of traffic in terms of bits per second, the load may be different if most connected terminal sets are farther away from the base station than if most connected terminal sets are nearby. The reason is that the radio link resources (specifically, power) required to support the traffic are different. Operation proceeds from step 404 to step 406 .

In step 406, the first base station determines the downlink transmission power budget according to the additional loading factor information corresponding to another base station connection point, which is the connection point of the first base station. For example, another connection point of the first base station and a second connection point of the second base station may correspond to adjacent sectors using the same downlink carrier frequency and the same downlink tone block, and the The determined downlink transmission power budget may correspond to another base station attachment point of the first base station. In some embodiments, the determined downlink transmission power budget is for a set of downlink communication channels comprising at least one pilot channel and a data traffic channel. In some such embodiments, the determined first portion of the power budget (the first portion allocated for the pilot channel) is independent of the first loading factor information and the second loading factor information, and the determined A second portion of the power budget of , the second portion allocated to correspond to a data traffic channel, is dependent on the second base station loading factor information and the additional loading factor information. For example, the pilot channel signal corresponding to the additional connection point of the first base station is broadcast with a first predetermined transmission power level independent of the loading conditions of the second loading factor information and the additional loading factor information; however, corresponding to the The traffic channel signal of the additional connection point of the first base station is transmitted at a power level which is a function of the second loading factor information and the additional loading factor information. Step 406 includes sub-steps 408 , 410 , 412 , 414 , 416 and 418 .

In sub-step 408, the first base station compares the additional loading factor information of the first base station with the second base station loading factor information. The compared loading factor information may refer to a downlink, eg downlink traffic channel radio link resource's downlink load. Operation proceeds from sub-step 408 to sub-step 410 . In sub-step 410, the first base station determines whether the comparison of sub-step 408 indicates that the second base station is loaded more than said first base station. If the check of step 410 indicates that the second base station load is greater than the first base station load, then operation proceeds to step 412, wherein the base station determines that the power budget corresponds to a first value indicative of the budget; otherwise operation proceeds from sub-step 410 Go to sub-step 414.

In sub-step 414, the first base station determines whether the comparison of sub-step 408 indicates that the second base station is loaded less than the first base station. If the check of step 414 indicates that the second base station load is less than the first base station load, then operation proceeds to sub-step 416, where the base station determines that the power budget corresponds to a power budget that is greater than that indicated by the first value. A second value for the power budget; otherwise, operation proceeds from sub-step 414 to sub-step 418. In sub-step 418, said first base station determines that said power budget corresponds to a third value indicative of said budget. For example, the third value may indicate a power budget between the power budget indicated by the first value and the power budget indicated by the second value.

In some embodiments, the base station load values compared in steps 410 and 420 are quantized into a representation of the actual load determination, and proceeding to step 418 may indicate the first base station load quantization degree value and the second base station load quantization degree value Same, indicating that the actual load determination of the first base station and the second base station is approximately the same.

In some embodiments, step 410 checks whether the load of the second base station is greater than the load of the first base station by a predetermined first amount, and step 410 checks whether the load of the second base station is greater than the load of the first base station by a predetermined second amount . Thus, if operation proceeds to step 418, it is indicated that the first base station load is about the same as the second base station load.

5 is a diagram of a flowchart 500 of an exemplary method of operating a first base station in a multiple access wireless communication system comprising a plurality of base stations in accordance with various embodiments. Each base station in the exemplary communication system includes at least one base station attachment point through which wireless terminals (eg, mobile nodes) in the vicinity of the base station can connect to the network. A base station may include one or more sectors. In this exemplary embodiment, a base station attachment point corresponds to a base station sector, uplink carrier, uplink OFDM tone block, downlink carrier, and downlink OFDM tone block.

Operation begins at step 502 where the first base station is powered on and initialized, and proceeds to step 504 . In step 504, the first base station receives second base station loading factor information indicating a load of a second base station connection point corresponding to the second base station. The second base station can be, and sometimes is, adjacent to the first base station. Operation proceeds from step 504 to step 506 .

In step 506, the first base station determines the downlink transmission power budget according to the additional loading factor information corresponding to another base station connection point, which is the connection point of the first base station. For example, another connection point of the first base station and a second connection point of the second base station may correspond to adjacent sectors using the same downlink carrier frequency and the same downlink tone block, and the The determined downlink transmission power budget may correspond to another base station connection point of the first base station. In some embodiments, the determined downlink transmission power budget is used for a set of downlink communication channels including at least one pilot channel and one data traffic channel. In some such embodiments, the first portion of the determined power budget (the first portion allocated for the pilot channel) is independent of the first loading factor information and the second loading factor information, and the determined power budget's The second portion, the second portion allocated to correspond to a data traffic channel, is dependent on the second base station loading factor information and the additional loading factor information. For example, the pilot channel signal corresponding to the additional connection point of the first base station is transmitted at a first predetermined transmission power level independent of the loading conditions of the second loading factor information and the additional loading factor information However, the traffic channel signal corresponding to the additional connection point of the first base station is transmitted at a power level that is a function of the second loading factor information and the additional loading factor information. Step 506 includes sub-steps 508 , 510 , 512 , 514 and 516 .

In sub-step 508, the first base station compares the current second base station loading factor information with previously stored second base station loading factor information. The compared loading factor information may refer to a downlink, eg downlink traffic channel radio link resource's downlink load. Operation proceeds from sub-step 508 to sub-step 510 . In sub-step 510, the first base station determines whether the comparison of sub-step 508 indicates an increase, a decrease or no change in the load of said second base station. If the determination of step 510 is that the load of the second connection point of the second base station has increased, then operation proceeds to step 512 where the first base station reduces the downlink transmission power budget. If the determination of step 510 is that the load of the second base station has not changed, then operation proceeds from step 510 to step 516 where the first base station has not changed the downlink transmission power budget. If the determination of step 510 is that the load of the second connection point of the second base station has decreased, then operation proceeds to step 514 where the first base station increases the downlink transmission power budget.

Figure 6 is a diagram of a flowchart 600 of an exemplary method of operating a first base station in a multiple access wireless communication system comprising a plurality of base stations in accordance with various embodiments. Each base station in the exemplary communication system includes at least one base station attachment point through which wireless terminals (eg, mobile nodes) in the vicinity of the base station can connect to the network. A base station may include one or more sectors. In this exemplary embodiment, a base station attachment point corresponds to a base station sector, uplink carrier, uplink OFDM tone block, downlink carrier, and downlink OFDM tone block.

Operation begins at step 602 where a first base station is powered on and initialized, and proceeds to step 604 . In step 604, the first base station receives second base station loading factor information indicating the loading of the second base station connection point corresponding to the second base station. The second base station can be, and sometimes is, adjacent to the first base station. Operation proceeds from step 604 to step 606 .

In step 606, the first base station determines the downlink transmission power budget according to the additional load factor information corresponding to another base station connection point, which is the connection point of the first base station. For example, another connection point of the first base station and a second connection point of the second base station may correspond to adjacent sectors using the same downlink carrier frequency and the same downlink tone block, and the The determined downlink transmission power budget may correspond to another base station attachment point of the first base station. In some embodiments, the determined downlink transmission power budget is for a set of downlink communication channels comprising at least one pilot channel and one data traffic channel. In some such embodiments, the first portion of the determined power budget, the first portion allocated for a pilot channel, is independent of the first loading factor information and the second loading factor information, and A second portion of the determined power budget, the second portion allocated to correspond to a data traffic channel, is dependent on second base station loading factor information and additional loading factor information. For example, the pilot channel signal corresponding to the additional connection point of the first base station is broadcast at a first predetermined transmission power level independent of the loading conditions of the second loading factor information and the additional loading factor information; A traffic channel signal of an additional connection point of a base station is transmitted at a power level that is a function of the second loading factor information and the additional loading factor information. Step 606 includes sub-steps 608 , 610 , 612 , 614 and 616 .

In sub-step 608, the first base station compares the current first base station loading factor information with previously stored first base station loading factor information. The compared loading factor information may refer to a downlink, eg downlink traffic channel radio link resource's downlink load. Operation proceeds from sub-step 608 to sub-step 610 . In sub-step 610, the first base station determines whether the comparison of sub-step 608 indicates an increase, a decrease or no change in the load of said first base station. If the determination of step 610 is that the load of the additional connection point of the first base station has increased, then operation proceeds to step 612 where the first base station increases the downlink transmission power budget. If the determination of step 610 is that the load of the first base station has not changed, then operation proceeds from step 610 to step 616 where the first base station does not change the downlink transmission power budget. If the determination of step 610 is that the load of the first base station has decreased, then operation proceeds to step 614 where the first base station reduces the downlink transmission power budget.

7 is a diagram 1000 illustrating features of various embodiments in which a base station in a wireless communication system including a plurality of base stations receives loading factor information corresponding to another base station and information to determine the downlink transmission power budget. Diagram 1000 includes exemplary diagram 1002 that includes base station 1 1050 and base station 2 1052 coupled together via network link 1068. Base station 1 1050 is coupled to a plurality of wireless terminal sets (WT 1 1054, WT 2 1056, WT 3 1058, WT 4 1060) via wireless links. Base station 2 1052 is coupled to a plurality of wireless terminal sets (WT 1' 1062, WT 4' 1064) via wireless links. BS 1 1050 has calculated a load factor 1071 corresponding to its current downlink traffic channel load. BS 2 1052 has calculated a load factor 1072 corresponding to its current downlink traffic channel load. BS 2 sends a message 1074 conveying its loading factor 1072 via backhaul network link 1068. BS 1 1052 receives the loading factor message 1074, recovers the loading factor corresponding to BS 2 1072 and compares the loading factor 1072 to its own loading factor 1070. BS 1 determines that BS 2's loading factor 1072 is less than its own loading factor 1070, and therefore sets its downlink transmission power budget to the first level. Diagram 1006 of diagram 1000 illustrates a downlink power budget for BS 1 corresponding to the example of diagram 1002. In diagram 1006, the height of arrow 1010 indicates the BS 1 downlink power budget for the determined condition in which the loading factor of base station 2 is less than the loading factor of base station 1. Downlink power budget 1010 may be divided into a first portion 1012 associated with downlink pilot channels, a second portion 1016 associated with downlink traffic channels, and a third portion 1014 associated with other downlink channels.

Diagram 1000 also includes exemplary diagram 1004 that includes base station 1 1050 and base station 2 1052 coupled together via network link 1068. Base station 1 1050 is coupled to a plurality of wireless terminal sets (WT 1 1054, WT 2 1056, WT 3 1058, WT 4 1060) via wireless links. At this time, the base station 2 1052 is coupled to a plurality of wireless terminals (WT1'1062, WT4'1064, WT5'1076, WT2'1078, WT6'1080, WT3'1082, WT7' 1084). BS 1 1050 has calculated a load factor 1086 corresponding to its current downlink traffic channel load. BS 2 1052 has calculated a load factor 1088 corresponding to its current downlink traffic channel load. BS 2 sends message 1090 conveying its loading factor 1088 via backhaul network link 1068. BS 1 1052 receives the loading factor message 1090, recovers the loading factor 1088 corresponding to BS 2 and compares the loading factor 1088 to its own loading factor 1086. BS 1 determines that BS 2's loading factor 1088 is greater than its own loading factor 1086, and therefore sets its downlink transmission power budget to a second level 1018, which is less than the first level 1010. Diagram 1008 of diagram 1000 illustrates a BS 1 downlink power budget corresponding to the example of diagram 1004. In graph 1008, the height of arrow 1018 indicates the BS 1 downlink power budget for the determined condition in which the loading factor of base station 2 is greater than the loading factor of base station 1. Downlink power budget 1018 may be divided into a first portion 1020 associated with downlink pilot channels, a second portion 1026 associated with downlink traffic channels, and a third portion 1024 associated with other downlink channels. In this example, note that the power levels 1012, 1020 associated with the pilot channel are the same regardless of the loading factor comparison determination; however, the downlink traffic channel power budget (1016, 1026) is vary with different outcomes.

8 is a diagram 1100 illustrating features of various embodiments in which a base station in a wireless communication system including a plurality of base stations receives loading factor information corresponding to another base station and bases station loading factor information based on the received base station loading factor information to determine the downlink transmission power budget. Diagram 1000 includes exemplary diagram 1102 that includes base station 1 1150 and base station 2 1152 coupled together via network link 1170 . Base station 1 1150 is coupled to a plurality of wireless terminal sets (WT 1 1154, WT 2 1156, WT 3 1158, WT 4 1160) via wireless links. Base station 2 1152 is coupled to a plurality of wireless terminal sets (WT 1' 1162, WT 2' 1164, WT 3' 1166, WT 4' 1168) via wireless links. BS 1 1150 has calculated a loading factor 1172 corresponding to its current downlink traffic channel load. BS 2 1152 has calculated a loading factor 1174 corresponding to its current downlink traffic channel load. BS 2 sends a message 1176 conveying its loading factor (LF _BS2 (t1)) 1174 via backhaul network link 1170 . BS1 1150 receives the loading factor message 1176, recovers the loading factor 1174 corresponding to BS2 and compares the loading factor 1174 to its own loading factor 1172. In this example, BS 1 determines that BS 2's loading factor 1174 is the same as its own loading factor 1172, and for the sake of illustration, it is assumed that both base stations are stable at these levels, and therefore Base Station 1 is no longer adjusted to the levels set to 1114 for its power budget. Diagram 1108 of diagram 1100 illustrates a downlink power budget for BS 1 corresponding to the example of diagram 1102 . In diagram 1108, the height of arrow 1114 indicates the BS 1 downlink power budget. Downlink power budget 1114 may be divided into a first portion 1116 associated with downlink pilot channels, a second portion 1120 associated with downlink traffic channels, and a third portion 1118 associated with other downlink channels.

Diagram 1100 also includes exemplary diagram 1104 that includes base station 1 1150 and base station 2 1152 coupled together via network link 1170 . Base station 11150 is coupled to a plurality of wireless terminal sets (WT 11154, WT2 1156, WT3 1158, WT4 1160) via wireless links. At this point, base station 2 1152 is coupled via wireless links to a plurality of wireless terminal sets (WT 1' 1162, WT 2' 1164, WT 3' 1166, WT 4' 1168, WT 5' 1178, WT 6' 1180, WT 7 '1182). BS 1 1150 has calculated a loading factor 1172 corresponding to its current downlink traffic channel load. BS2 1152 has calculated a loading factor (LF _BS2 (t2)) 1184 corresponding to its current downlink traffic channel load. BS 2 sends a message 1186 conveying its loading factor 1184 via backhaul network link 1170 . BS1 1150 receives the loading factor message 1186, retrieves the loading factor 1184 for BS2 and compares the loading factor 1184 to the previously stored loading factor (LF _BS2 (t1)) 1174 for BS2. BS 1 determines that BS 2's current loading factor 1184 is greater than BS 2's previous loading factor 1174, and therefore reduces its downlink transmit power budget to level 1122. Diagram 1110 of diagram 1100 illustrates a downlink power budget for BS 1 corresponding to the diagram 1104 example. In graph 1100 , the height of arrow 1122 indicates the downlink power budget adjusted by BS 1 for the determined condition in which the current loading factor of base station 2 is greater than the previous loading factor of base station 2 . Downlink power budget 1122 may be divided into a first portion 1124 associated with downlink pilot channels, a second portion 1128 associated with downlink traffic channels, and a third portion 1126 associated with other downlink channels. In this example, note that the power levels 1116, 1124 associated with the pilot channel are the same regardless of the loading factor comparison determination; however, the downlink traffic channel budget (1120, 1128) responds to vary with different outcomes.

Diagram 1100 also includes exemplary diagram 1106 that includes base station 1 1150 and base station 2 1152 coupled together via network link 1170 . Base station 1 1150 is coupled to a plurality of wireless terminal sets (WT 1 1154, WT 2 1156, WT 3 1158, WT 4 1160) via wireless links. At this point, base station 2 1152 is coupled to a plurality of wireless terminal sets (WT 1' 1162, WT 4' 1168) via wireless links. BS 1 1150 has calculated a loading factor 1172 corresponding to its current downlink traffic channel load. BS2 1152 has calculated a loading factor (LF _BS2 (t3)) 1188 corresponding to its current downlink traffic channel load. BS 2 sends message 1190 conveying its loading factor 1188 via backhaul network link 1170 . BS 1 1150 receives loading factor message 1190, retrieves loading factor 1188 for BS 2 and compares loading factor 1188 to a previously stored loading factor (LF _BS2 (t2)) 1184 for BS 2. BS 1 determines that BS 2's current loading factor 1188 is less than BS 2's previous loading factor 1184, and therefore increases its downlink transmit power budget to level 1130. Diagram 1112 of diagram 1100 illustrates a downlink power budget for BS 1 corresponding to the diagram 1106 example. In graph 1112 , the height of arrow 1130 indicates the BS 1 adjusted downlink power budget for the determined condition in which the current loading factor of base station 2 is less than the previous loading factor of base station 2 . Downlink power budget 1130 may be divided into a first portion 1132 associated with downlink pilot channels, a second portion 1136 associated with downlink traffic channels, and a third portion 1134 associated with other downlink channels. In this example, note that the power levels 1124, 1132 associated with the pilot channel are the same regardless of the loading factor comparison determination; however, the downlink traffic channel power budget (1128, 1136) is Varies with different results of the trace.

9 is a diagram 1200 illustrating features of various embodiments in which a base station in a wireless communication system including multiple base stations receives loading factor information corresponding to another base station and determines a downlink link based on the base station loading factor information. transmission power budget. Diagram 1200 includes exemplary diagram 1202 that includes base station 1 1250 and base station 2 1252 coupled together via network link 1270 . Base station 1 1250 is coupled to a plurality of wireless terminal sets (WT 1 1254, WT 2 1256, WT 3 1258, WT 4 1260) via wireless links. Base station 2 1252 is coupled to a plurality of wireless terminal sets (WT 1' 1262, WT 2' 1264, WT 3' 1266, WT4' 1268) via wireless links. BS1 1250 has calculated a loading factor (LF _BS1 (t1)) 1272 corresponding to its current downlink traffic channel load. BS 2 1252 has calculated a loading factor 1274 corresponding to its current downlink traffic channel loading. BS 2 sends a message 1276 conveying its loading factor (LF _BS2 ) 1274 via backhaul network link 1270 . BS 1 1250 receives the loading factor message 1276, recovers the loading factor 1274 corresponding to BS 2 and compares the loading factor 1274 to its own loading factor 1272. In this example, BS 1 determines that BS 2's loading factor of 1274 is the same as its own loading factor of 1272, and for the sake of illustration, it will be assumed that both base stations are stable at these levels, and therefore Base Station 1 no longer adjusts to the levels set to 1214 for its power budget. Diagram 1208 of diagram 1200 illustrates a BS 1 downlink power budget corresponding to the diagram 1202 example. In diagram 1208, the height of arrow 1214 indicates the BS 1 downlink power budget. Downlink power budget 1214 may be divided into a first portion 1216 associated with downlink pilot channels, a second portion 1220 associated with downlink traffic channels, and a third portion 1218 associated with other downlink channels.

Diagram 1200 also includes exemplary diagram 1204 that includes base station 1 1250 and base station 2 1252 coupled together via network link 1270 . At this point, base station 1 1250 is coupled to a plurality of wireless terminal sets (WT 1 1254, WT 2 1256, WT 3 1258, WT 4 1260, WT 5 1278, WT 6 1280, WT 7 1282) via wireless links. At this point, base station 2 1252 is coupled to a plurality of wireless terminal sets (WT 1' 1262, WT 2' 1264, WT 3' 1266, WT4' 1268) via wireless links. BS1 1250 has calculated a loading factor (LF _BS1 (t2)) 1272 corresponding to its current downlink traffic channel load. BS2 1252 has calculated a loading factor (LF _BS2 ) 1274 corresponding to its current downlink traffic channel load. BS 2 sends message 1276 via backhaul network link 1270 conveying its load factor 1274 . BS 1 1250 receives the loading factor message 1276, recovers the loading factor 1274 corresponding to BS 2 and recognizes that the loading factor corresponding to BS 2 remains unchanged. BS1 1250 compares its current loading factor 1284 to a previously stored loading factor (LF _BS1 (t1)) 1272 for BS1. BS 1 determines that BS 1's current loading factor 1284 is greater than BS 1's previous loading factor 1272 and therefore increases its downlink transmit power budget to level 1222. Diagram 1210 of diagram 1200 illustrates a downlink power budget for BS 1 corresponding to the diagram 1204 example. In graph 1210 , the height of arrow 1222 indicates the downlink power budget adjusted by BS 1 for the determined condition in which the current loading factor of base station 1 is greater than the previous loading factor of base station 1 . Downlink power budget 1222 may be divided into a first portion 1224 associated with downlink pilot channels, a second portion 1228 associated with downlink traffic channels, and a third portion 1226 associated with other downlink channels. In this example, note that the power levels 1216, 1224 associated with the pilot channel are the same regardless of the loading factor comparison determination; however, the downlink traffic channel power budget (1220, 1228) is vary with different outcomes.

Diagram 1200 also includes exemplary diagram 1206 that includes base station 1 1250 and base station 2 1252 coupled together via network link 1270 . At this point, base station 1 1250 is coupled to a plurality of wireless terminal sets (WT 3 1258, WT 4 1260) via wireless links. At this point, base station 2 1252 is coupled to a plurality of wireless terminal sets (WT 1' 1262, WT2' 1264, WT 3' 1266, WT 4' 1268) via wireless links. BS 1 1250 has calculated a loading factor (LF _BS1 (t3) 1286 corresponding to its current downlink traffic channel load. BS 2 1252 has calculated a loading factor (LF _BS2 ) 1274 corresponding to its current downlink traffic channel load. BS 2 sends a message 1276 conveying its loading factor 1274 via backhaul network link 1270. BS 1 1250 receives the loading factor message 1276, recovers the loading factor 1274 corresponding to BS 2 and recognizes that the loading factor corresponding to BS 2 remains unchanged. BS 1 compares its current loading factor 1286 with a previously stored loading factor (LF _BS1 (t2)) 1284 corresponding to BS 1. BS 1 determines that BS 1's current loading factor 1286 is less than BS 1's previous loading factor 1284, and Its downlink transmit power budget is thus reduced to level 1230. Diagram 1212 of diagram 1200 illustrates the BS 1 downlink power budget corresponding to the example diagram 1206. In diagram 1212, the height of arrow 1230 indicates the current A downlink power budget adjusted by BS 1 for the determined condition that the loading factor is less than the previous loading factor of base station 1. The downlink power budget 1230 may be divided into a first part 1232 related to the downlink pilot channel, a first part 1232 related to the downlink traffic A second part 1236 related to the channel and a third part 1234 related to other downlink channels. In this example, it should be noted that the power levels 1224, 1232 related to the pilot channel are the same regardless of the loading factor comparison determination; However, the downlink traffic channel power budget (1228, 1236) changes in response to different results from the loading factor comparison.

FIG. 10 , comprising the combination of FIG. 10A and FIG. 10B , is a diagram of a flowchart 2000 of an exemplary method of operating a base station in accordance with various embodiments. The exemplary base station (eg, base station 200 in FIG. 2 ) may be a base station in a multiple access wireless communication system including multiple base stations, each base station including at least one base station connection point. Operation begins at step 2002, where the base station is powered on and initialized. Operation proceeds from start step 2002 to step 2004, step 2010, step 2020 and step 2034 via connecting node A 2032.

In step 2004, which is performed on a round-robin basis, the base station determines the downlink load for each base station connection point. The output of step 2004 is base station 1 downlink load factor 2006 , . . . , base station 1 connection point n downlink load factor 2008 . Information ( 2006 , . . . , 2008 ) is the input of steps 2020 and 2034 .

In step 2010, the base station receives downlink loading factor information corresponding to other base stations (eg, neighboring base stations). The reception may be via an interface to a backhaul network and/or via a wireless receiver, for example by a wireless terminal connected to both the base station and another base station acting as a repeater. The receiving may be performed on a recurring basis in response to a request and/or in response to a decision by another base station to communicate its downlink load information. The information corresponding to the various connection points of one or more base stations is the output of step 2010 (base station 2 connection point 1 downlink loading factor 2012, ..., base station 2 connection point m downlink loading factor 2014, .. ., base station N connection point 1 downlink load factor 2016, ..., base station N connection point p downlink load factor 2018). The information (2012, 2014, 2016, 2018) is the input of step 2020.

Step 2020 is performed for each connection point of the base station on an ongoing basis. In step 2020, the base station determines a downlink transmission power budget according to load factor information corresponding to one or more other base stations (eg, neighboring base stations). In some embodiments, the determined downlink transmission power budget is the power budget of a group of downlink communication channels including at least one pilot channel and one data channel, and the transmission power level of the pilot channel (such as pilot channel power per tone) is independent of loading information, whereas the portion of the determined downlink power budget corresponding to a traffic channel depends on the loading information of the base station connection point to which the budget corresponds and one or more neighboring base stations Loads of one or more adjacent points of the . Step 2020 includes sub-steps 2022 , 2024 , 2026 and 2028 . In sub-step 2022, the base station compares the current load of the considered base station connection point with the load of one or more connection points of one or more neighboring base stations that may interfere with the considered connection point. In sub-step 2024, the base station compares the current load of the considered base station attachment point with the previous load of the considered base station attachment point. In sub-step 2026, the base station compares the current load of the potentially interfering neighboring base station connection point with the previous loading of the same potentially interfering neighboring base station connection point. Sub-step 2026 may be performed for a plurality of different potentially interfering neighboring base station attachment points.

Operation proceeds from sub-steps 2022 , 2024 and 2026 to sub-step 2028 . In sub-step 2028, the base station according to the change of the load of the base station connection point over time, the change of the load of the adjacent base station connection point over time, the comparison result of the load of the considered base station connection point and the load of one or more connection points of the neighboring base station, The current downlink transmission power budget, the previous downlink transmission power budget and the alternative possible downlink transmission power budget adjust the base station connection point downlink transmission power budget. Sub-step 2028 includes sub-step 2030 . In sub-step 2030, the base station adjusts the base station connection point downlink traffic channel power budget.

In some embodiments, determining the power budget for a base station attachment point includes determining the power budget when the comparison indicates that the load of the attachment points of other base stations (e.g. neighboring base stations) is greater than the load of the base station attachment point to which the budget applies corresponds to a first value indicative of the budget; and when the comparison indicates that other base stations (e.g., neighboring base stations) are less loaded than the base station attachment point to which the budget applies, determining that the power budget corresponds to a value greater than indicated by A second value of the power budget of the power budget indicated by the first value.

In various embodiments, determining the power budget of the base station's connection point includes reducing the current power budget in response to detecting an increase in loading of the connection point of other base stations (eg, neighboring base stations). In some embodiments, determining the power budget of the base station's connection point includes increasing the current power budget in response to detecting a decrease in connection point loading of other base stations (eg, neighboring base stations).

In various embodiments, determining the power budget of the base station connection point includes increasing the current power budget in response to detecting an increase in loading of said connection point. In some embodiments, determining the power budget of the base station connection point comprises reducing the current power budget in response to detecting a decrease in loading of said connection point.

In some embodiments, for an attachment point, the base station supports multiple (eg, two, three, or more than three) predetermined downlink transmission power budget alternative levels, and for an attachment point At a given time, the base station chooses to use one of the possible alternative levels. Thus, a base station can dynamically vary its power budget between possible alternatives in response to load changes, including load changes of neighboring base stations. In some embodiments, a base station may communicate information identifying its selected downlink transmission power budget level to other base stations (eg, neighboring base stations).

In step 2034, the base station generates a message conveying downlink load information of the base station attachment point. The base station connection point load information (BS1 connection point 1 downlink load factor 2006, ..., base station 1 connection point n downlink load factor 2008) is the output of step 2034. Operation proceeds from step 2034 to step 2036. In step 2036, the base station transmits the message generated in step 2034, including the determined base station attachment point load factor information directed to one or more other base stations (eg, neighboring base stations). Transmissions directed to a neighboring base station may be via an interface to a backhaul network and/or via a wireless terminal coupled to the base station and the neighboring base station. The operations of steps 2034 and 2036 are performed on an ongoing basis, eg, as part of a recurring timing structure, in response to requests from neighboring base stations and/or based on a base station's decision to communicate its load information to one or more neighboring base stations. In some embodiments, the downlink loading factor of one of said base station connection points is changed in response to the base station determining that its load has reached a high level and/or in response to a detected load change (a change of a predetermined amount) is communicated to one or more selected neighboring base stations.

Although described in the context of an OFDM system, the methods and apparatus of various embodiments are applicable to a wide range of communication systems, including many non-OFDM and/or non-cellular systems.

In various embodiments, the nodes described herein are implemented using one or more modules to perform steps corresponding to one or more methods, e.g., signal processing, beacon generation, beacon detection, beacon measurement, connection Compare, connect and implement. In some embodiments, various features are implemented using modules. The modules may be implemented using software, hardware, or a combination of software and hardware. Many of the above-described methods or method steps can be implemented using machine-executable instructions, such as software, contained in a machine-readable medium (such as a memory device such as RAM, a floppy disk, etc.) to control a machine (such as a computer with or without additional hardware) general-purpose computer) to implement all or part of the methods described above, for example, within one or more nodes. Accordingly, various embodiments are directed to a machine-readable medium comprising machine-executable instructions to cause a machine (eg, a processor and associated hardware) to perform one or more steps of the methods described above.

Numerous additional variations on the methods and apparatus described above will be apparent to those of ordinary skill in the art in view of the above description. Such variations are considered to be within the scope. The methods and apparatus of various embodiments (and in various embodiments) can be used with CDMA, Orthogonal Frequency Division Multiplexing (OFDM), and/or to provide a wireless communication link between an access node and a mobile node It is used with many other types of communication technologies on the road. In some embodiments, an access node is implemented as a base station that establishes a communication link with a mobile node using OFDM and/or CDMA. In various embodiments, mobile nodes are implemented as notebook computers, personal data assistants (PDAs), or other portable devices that include receiver/transmitter circuitry and logic and/or routines to implement the various embodiments. method.

Claims (35)

1. One kind in comprising the multi-address radio communication system of a plurality of base stations the operation first base station method, each in described a plurality of base stations comprises at least one base station tie point, described method comprises:

   Receive the second base station on-load factor information of indication corresponding to the second base station tie point load of second base station; And

   Determine the downlink transmitted power budget according to the described second base station on-load factor information that receives.
2. 2. method according to claim 1 is wherein further determined the downlink transmitted power budget according to carrying out corresponding to the extra load factor information of another base station tie point.
3. 3. method according to claim 2,

   Wherein said another base station tie point is corresponding to described first base station, and

   Wherein said definite downlink transmitted power the budget includes more described extra load factor information and described second base station on-load factor information.
4. 4. method according to claim 2, the downlink transmitted power budget that wherein said warp is determined is the power budget that comprises one group of downlink communication channel of an at least one pilot channel and a data traffic channels; And

   The part of the downlink transmitted power budget that the described warp of wherein said pilot channel is determined is irrelevant with described extra load factor information and the described second on-load factor information, and wherein depends on described second base station on-load factor information and described extra load factor information corresponding to the part of the definite downlink transmitted power budget of the described warp of described data traffic channels.
5. 5. method according to claim 3, determine that wherein described power budget comprises:

   When relatively indicating the described second base station load, determine first value of described power budget when described corresponding to the described budget of indication greater than the described first base station load; And

   When described when relatively indicating the described second base station load less than the described first base station load, determine described power budget corresponding to indication greater than second value by the power budget of the indicated described power budget of described first value.
6. 6. method according to claim 2, determine that wherein described power budget comprises:

   Increase in response to the load that detects described second base station reduces the current power budget.
7. 7. method according to claim 2, determine that wherein described power budget comprises:

   Reduction in response to the load that detects described second base station increases the current power budget.
8. 8. method according to claim 2, determine that wherein described power budget comprises:

   Increase in response to the load that detects described first base station increases the current power budget.
9. 9. method according to claim 2, determine that wherein described power budget comprises:

   Reduction in response to the load that detects described first base station reduces the current power budget.
10. 10. base station, it comprises:

    Be used to receive the device of indication corresponding to the base station on-load factor information of the load of the base station tie point of another base station; And

    Be used for determining the device of downlink transmitted power budget, the wherein said device that is used for definite downlink transmitted power budget is determined described downlink transmitted power budget according to the described base station on-load factor information that receives.
11. 11. base station according to claim 10, the wherein said device of definite downlink transmitted power budget that is used for is according to determining described downlink transmitted power budget corresponding to the extra load factor information of additional base stations tie point.
12. 12. base station according to claim 11,

    Wherein said additional base stations tie point is corresponding to described base station, and

    The wherein said device that is used for definite downlink transmitted power budget comprises the device that is used for more described extra load factor information and described other base station on-load factor information.
13. 13. base station according to claim 11, the downlink transmitted power budget that wherein said warp is determined is the power budget that comprises one group of downlink communication channel of an at least one pilot channel and a data traffic channels; And

    The part of the power budget that the described warp of wherein said pilot channel is determined is irrelevant with described other on-load factor information and described extra load factor information, and wherein depends on described other base station on-load factor information and described extra load factor information corresponding to the part of the definite downlink transmitted power budget of the described warp of described data traffic channels.
14. 14. base station according to claim 12, the wherein said device that is used for determining the downlink transmitted power budget when relatively indicating described other base station loads greater than the load of described base station, determines that described downlink transmitted power budget is corresponding to first value of indicating described budget when described; And when described when relatively indicating described other base station loads less than the load of described base station, determine described downlink transmitted power budget corresponding to indication greater than second value by the power budget of the indicated described power budget of described first value.
15. 15. base station according to claim 11, the wherein said device that is used for determining the downlink transmitted power budget reduces the current power budget in response to the increase of the load that detects described other base stations.
16. 16. base station according to claim 11, the wherein said device that is used for determining the downlink transmitted power budget increases the current power budget in response to the reduction of the load that detects described second base station.
17. 17. base station according to claim 11, the wherein said device that is used for determining the downlink transmitted power budget comprises the device that the load that is used to follow the trail of described base station changes, and the wherein said device that is used for determining the downlink transmitted power budget increases the current power budget in response to the increase of the load that detects described base station.
18. 18. base station according to claim 11, the wherein said device that is used for determining the downlink transmitted power budget comprises the device that the load that is used to follow the trail of described base station changes, and the wherein said device that is used for determining the downlink transmitted power budget reduces the current power budget in response to the reduction of the load that detects described base station.
19. 19. a base station, it comprises:

    Interface, it is used to receive the signal of reception and registration indication corresponding to the base station on-load factor information of the load of at least one base station tie point of at least one other base station;

    On-load factor information is recovered module, and it is used for from the on-load factor information of the described signal recovery that receives corresponding at least one other base station;

    Downlink transmitted power budget determination module, wherein said downlink transmitted power budget determination module is according to the described downlink transmitted power budget of determining the tie point of described base station through the on-load factor information of recovering corresponding at least one other base station.
20. 20. base station according to claim 19, it further comprises:

    The on-load factor determination module, it is used for determining the on-load factor corresponding to the tie point of described base station;

    The on-load factor comparison module, it is used for on-load factor that comparison determines corresponding to the described warp of the tie point of described base station and the on-load factor through recovering corresponding to the tie point of another base station, and wherein said downlink transmitted power budget determination module uses the result of described on-load factor comparison module to determine described downlink power budget.
21. 21. base station according to claim 19, the power budget that wherein said warp is determined is the power budget that comprises one group of downlink communication channel of an at least one pilot channel and a data traffic channels; And

    The part of the power budget that the described warp of wherein said pilot channel is determined has nothing to do with described other on-load factor information and described extra load factor information, and wherein depends on described other base station on-load factor information and described extra load factor information corresponding to the part of the described power budget of described data traffic channels.
22. 22. base station according to claim 21, when wherein said downlink transmitted power budget determination module is determined described other base station loads greater than the load of described base station when described on-load factor comparison module, determine first value of described power budget corresponding to the described budget of indication; And when described other base station loads of described on-load factor comparison module indication during less than the load of described base station, determine described power budget corresponding to indication greater than second value by the power budget of the indicated described power budget of described first value.
23. 23. base station according to claim 21, it further comprises:

    The on-load factor tracing module, it is used to follow the trail of the change of the on-load factor of base station tie point, and wherein said downlink transmitted power budget determination module reduces the current power budget in response to the increase of the load that detects one in described other base stations.
24. 24. base station according to claim 21, it further comprises:

    The on-load factor tracing module, it is used to follow the trail of the change of the on-load factor of base station tie point, and wherein said downlink transmitted power budget determination module increases the current power budget in response to the reduction of the load that detects one in described other base stations.
25. 25. base station according to claim 21, it further comprises:

    The on-load factor tracing module, it is used to follow the trail of the change of the on-load factor of base station tie point, and wherein said downlink transmitted power budget determination module increases the current power budget in response to the increase of the load of the tie point that detects described base station.
26. 26. base station according to claim 21, it further comprises:

    The on-load factor tracing module, it is used to follow the trail of the change of the on-load factor of base station tie point, and wherein said downlink transmitted power budget determination module reduces the current power budget in response to the reduction of the load of the tie point that detects described base station.
27. 27. a computer-readable media, it comprises and is used for controlling the machine-executable instruction that a method is implemented in first base station at the multi-address radio communication system that comprises a plurality of base stations, and described method comprises:

    Receive the second base station on-load factor information of indication corresponding to the load of the second base station tie point of second base station; And

    Determine the downlink transmitted power budget according to the described second base station on-load factor information that receives.
28. 28. computer-readable media according to claim 27, it further comprises machine-executable instruction and determines described downlink transmitted power budget with basis corresponding to the extra load factor information of another base station tie point.
29. 29. computer-readable media according to claim 28, wherein said another base station tie point is corresponding to described first base station.
30. 30. computer-readable media according to claim 29, its further comprise machine-executable instruction with:

    Compare extra load factor information and the described second base station on-load factor information, as a part of determining described downlink transmitted power budget.
31. 31. computer-readable media according to claim 30, the downlink transmitted power budget that wherein said warp is determined is the power budget that comprises one group of downlink communication channel of an at least one pilot channel and a data traffic channels; And

    The part of the downlink transmitted power budget that the described warp of wherein said pilot channel is determined is irrelevant with described extra load factor information and the described second on-load factor information, and wherein depends on described second base station on-load factor information and described extra load factor information corresponding to the part of the definite downlink transmitted power budget of the described warp of described data traffic channels.
32. 32. the base station that can operate in communication system, described base station comprises:

    Processor, it is configured to:

    Receive the second base station on-load factor information of indication corresponding to the load of the second base station tie point of second base station; And

    Determine the downlink transmitted power budget according to the described second base station on-load factor information that receives.
33. 33. base station according to claim 32, wherein said processor further is configured to:

    Determine described downlink transmitted power budget according to extra load factor information corresponding to another base station tie point.
34. 34. base station according to claim 33,

    Wherein said another base station tie point is corresponding to described first base station, and

    Wherein said processor further is configured to determine described downlink transmitted power budget by the operation that comprises comparison extra load factor information and the described second base station on-load factor information.
35. 35. base station according to claim 34, the downlink transmitted power budget that wherein said warp is determined is the power budget that comprises one group of downlink communication channel of an at least one pilot channel and a data traffic channels; And

    The part of the downlink transmitted power budget that the described warp of wherein said pilot channel is determined is irrelevant with described extra load factor information and the described second on-load factor information, and wherein depends on described second base station on-load factor information and described extra load factor information corresponding to the part of the definite downlink transmitted power budget of the described warp of described data traffic channels.

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