US20080219201A1 - Method of Clustering Devices in Wireless Communication Network - Google Patents
Method of Clustering Devices in Wireless Communication Network Download PDFInfo
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- US20080219201A1 US20080219201A1 US12/066,882 US6688206A US2008219201A1 US 20080219201 A1 US20080219201 A1 US 20080219201A1 US 6688206 A US6688206 A US 6688206A US 2008219201 A1 US2008219201 A1 US 2008219201A1
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- 238000004891 communication Methods 0.000 title claims abstract description 131
- 238000000034 method Methods 0.000 title claims description 47
- 238000005259 measurement Methods 0.000 claims abstract description 43
- 238000001228 spectrum Methods 0.000 claims abstract description 16
- 239000013598 vector Substances 0.000 claims description 25
- 101100368149 Mus musculus Sync gene Proteins 0.000 claims description 23
- 230000008859 change Effects 0.000 claims description 3
- 238000012937 correction Methods 0.000 claims description 3
- 238000012935 Averaging Methods 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 description 6
- 230000008901 benefit Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W24/00—Supervisory, monitoring or testing arrangements
- H04W24/10—Scheduling measurement reports ; Arrangements for measurement reports
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/204—Multiple access
- H04B7/216—Code division or spread-spectrum multiple access [CDMA, SSMA]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
- H04W36/302—Reselection being triggered by specific parameters by measured or perceived connection quality data due to low signal strength
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
Definitions
- This invention pertains to the field of wireless communication networks, and more particularly to a method of clustering devices in a wireless communication network.
- the Federal Communications Commission has recently released a proposed rulemaking to allow unlicensed wireless communication networks to operate on certain bands presently utilized by other, existing (“incumbent”), radio services, such as broadcast television.
- the FCC proposed standards to prevent the unlicensed wireless network's transmitting devices from interfering with the incumbent radio services. For example, these unlicensed transmitting devices are required to vacate any channel within a short time period (e.g., a few seconds) after an incumbent transmitter begins operating.
- One method of insuring that a transmitting device of an unlicensed wireless network vacates a channel when required to do so is for the device to periodically stop transmitting and to “listen” for incumbent transmitters by checking all channels within their operating band(s) for the presence of any transmissions from incumbent transmitters. If the device detects the presence of any incumbent radio transmissions, the device is then required to take appropriate measures (e.g., change channels; reduce power; shut down; etc.) to insure that it does not interfere with the incumbent signal(s).
- appropriate measures e.g., change channels; reduce power; shut down; etc.
- FIG. 1 shows an exemplary unlicensed wireless communication network 100 comprising a base station (BS) 110 , and a plurality of remote terminals (RTs) 120 .
- wireless communication network 100 may be a Wireless Regional Area Networks (WRAN).
- WRAN Wireless Regional Area Networks
- One typical application is broadband service where RTs 120 are on the consumer side (e.g., broadband modems) while BS 110 belongs to the service provider and services many RTs 120 .
- RTs 120 may be fixed or mobile devices.
- wireless communication network 100 may have as many as 100 or more RTs operating with BS 110 .
- external transmitters 150 e.g., incumbent television transmitters
- new external transmitters 150 also may begin transmitting at any time, and these new transmitters are also considered incumbents so that their signals must be protected from interference by transmissions from any of RTs 120 or BS 110 .
- BS 110 and all of the RTs 120 are required to periodically stop transmitting and listen for incumbent transmitters on every possible channel in order to meet the channel vacation requirements, the time required for this checking may be considerable and the frequency may be often, and this can significantly decrease the availability of wireless communication network 100 .
- wireless communication network 100 may operate over an area with a diameter on the order of tens of miles. So it is possible that a first group of RTs 120 may be located many miles closer to an incumbent external transmitter 150 than a second group of RTs 120 . In that case, communication on one or more channels may be forbidden for the RTs 120 in the first group in order to protect the signal of the incumbent external transmitter 150 , but communication on these same channels may be permissible for the second group of RTs 120 that are located many miles away from incumbent external transmitter 150 .
- the second group of RTs 120 may be located many miles closer than the first group of RTs 120 to a different, second incumbent external transmitter 150 , so that communication on one or more different channels may be permissible for the first group of RTs 120 , but forbidden for the second group of RTs 120 .
- BS 110 may know the locations and frequencies of all of the incumbent external transmitters 150 in its operating area, in general BS 110 has no convenient way of knowing which RTs 120 are located near which incumbent external transmitter 150 . In that case, it may be forced to disable communication with all of the RTs 120 on all of the channels on which any of the incumbent external transmitters 150 are operating. This reduces the efficiency and data capacity of the network.
- RTs 120 that are located in close proximity to each other to be able to communicate with each other directly, without passing data or messages through BS 110 .
- BS 110 and RTs 120 have no convenient way of knowing which RTs 120 are located in close proximity, it is not practical to enable such direct communications.
- a method of communication comprises dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on at least one characteristic, measured by one or more of the remote terminals, of one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network; and selecting at least one parameter of a communication between the base station and each remote terminal according to a cluster to which each remote terminal belongs.
- a method of communication comprises determining a location of each of the plurality of remote terminals with respect to the base station; dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on the determined location of each remote terminal so as to group remote terminals together in each cluster according to their proximity to each other; and selecting at least one parameter of a communication between the base station and each remote terminal according to a cluster to which each remote terminal belongs.
- a method of determining a location of each of the plurality of remote terminals with respect to the base station comprises: (a) determining a distance, d 12 , between the base station and the remote terminal, based on a turnaround time interval, t 12 , for a token to be transmitted roundtrip between the base station and the remote terminal; (b) determining a time of arrival, t 1 , at the base station of a sync signal included in an external signal transmitted by an external terrestrial transmitter not associated with the wireless communication network and located at a known location; (c) determining a time interval, t 02 , for the external signal to travel from the external terrestrial transmitter to the remote terminal using: (1) a known distance d 01 between the base station and the external terrestrial transmitter, (2) the time of arrival t 1 , and (3) a time of arrival, t 2 , at the remote terminal of the sync signal included in the external signal transmitted by the
- a method of communication comprises dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on at least one characteristic, measured by one or more of the remote terminals, of one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network; and enabling each remote terminal to communicate data directly with other remote terminals in its assigned cluster without passing the data through the base station.
- a method of communication comprises dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on at least one characteristic, measured by one or more of the remote terminals, of one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network; and selecting which ones among the plurality of remote terminals will perform frequency spectrum profile measurements of a frequency band used by the external terrestrial transmitters not associated with the wireless communication network, according to the clusters to which they are assigned.
- FIG. 1 shows a wireless communication network
- FIG. 2 illustrates a wireless communication network including remote terminals divided into clusters
- FIG. 3 shows a diagram for explaining a method of determining the location of a remote terminal in a wireless communication network
- FIG. 4 illustrates a wireless communication network where remote terminals are divided into clusters based on geographical proximity to each other;
- FIG. 5 illustrates a frequency spectrum profile measurement of incumbent transmissions in a frequency band used by a communication network
- FIG. 6 shows a flowchart of a method of dividing remote terminals into clusters, and assigning the remote terminals to the clusters, in a wireless communication network.
- an external terrestrial transmitter not associated with the wireless communication network refers to any terrestrial radio transmitter that transmits its signal independently of the operation of the wireless communication network, for example: a terrestrial analog or digital television broadcast transmitter; a television relay transmitter; a terrestrial commercial radio broadcast transmitter; a radio repeater in the public service or amateur radio bands; etc.
- Disclosed herein is a method of communication for a wireless communication network comprising a base station and a plurality of remote terminals.
- the method divides the plurality of remote terminals into a plurality of clusters for communication with the base station, and assigns each of the remote terminals to one of the clusters.
- FIG. 2 illustrates a wireless communication network 200 including a base station (BS) 210 and a plurality of remote terminals (RTs) 220 divided into clusters 230 .
- BS base station
- RTs remote terminals
- each of the RTs 220 is assigned to one of the clusters 230 based on at least one characteristic, measured by one or more of the RTs 220 , of one or more external signals transmitted by one or more external terrestrial transmitters 250 not associated with the wireless communication network 200 .
- the measured characteristic is a time of arrival at an RT 220 of a sync signal included in an external signal transmitted by the external terrestrial transmitter 250 .
- the sync signal may be a field sync sequence in the DTV broadcast signal.
- the measured time of arrival of the sync sequence at RT 220 is used to calculate the location of the RT 220 , which is in turn used to assign RT 220 to a particular cluster 230 .
- the measured characteristic is “profile” of incumbent transmissions from all of the external terrestrial transmitters 250 that are received at each of the RTs 220 .
- the incumbent profile may be a frequency spectrum profile, measured at each of the RTs 220 , produced by the external signals from the external terrestrial transmitters 250 .
- RTs 220 are assigned to clusters 230 in order to group together in each cluster 230 RTs 220 having similar incumbent (e.g., frequency spectrum) profiles.
- FIG. 3 shows a diagram for explaining a method of determining the location of a remote terminal in a wireless communication network based on a time of arrival of an external signal transmitted by one or more external terrestrial transmitters not associated with the wireless communication network.
- FIG. 3 shows a base station (BS) 210 , a remote terminal (RT) 220 , and an external terrestrial transmitter 250 (e.g., a terrestrial broadcast television (TV) transmitter) not associated with the wireless communication network 200 .
- BS base station
- RT remote terminal
- an external terrestrial transmitter 250 e.g., a terrestrial broadcast television (TV) transmitter
- the location (x 1 , y 1 ) of BS 210 is assumed to be known.
- the location (x 0 , y 0 ) of external terrestrial transmitter 250 is also assumed to be known (a record of the location of TV transmitters in the United States is maintained by the FCC).
- the distance d 01 between TV transmitter 250 and BS 210 can be calculated and stored in BS 210 .
- the locations of BS 210 and TV transmitter 250 can be separately stored in BS 210 .
- BS 210 may determine the distance d 12 between the RT 220 and itself in the following way. First, BS 210 transmits a token to RT 220 and requests that RT 220 respond back to BS 210 . The turnaround time, t RT , to receive the response from RT 220 , minus any processing time, can be used to calculate the distance d 12 between the BS 210 and RT 220 according to the following equation:
- the distance d 02 between the TV transmitter 250 and RT 220 is determined as follows.
- a terrestrial television broadcast signal typically contains a known synchronization signal.
- a terrestrial digital television (DTV) broadcast signal has a certain repetitive structure.
- a terrestrial DTV transmitter in the United States transmits a known signal (called a “frame sync”) every 24.2 ms.
- This known signal can be used to compute the distance d 02 between TV station 250 and RT 220 , as follows.
- BS 210 instructs ST 220 to search for the sync sequence in a television signal transmitted by TV transmitter 250 .
- the time of arrival, t 2 of the sync sequence at RT 220 is determined.
- BS 210 also searches for the sync sequence in the TV signal transmitted by TV transmitter 250 , and records the time of arrival, t 1 , of the sync sequence at its location.
- the time interval, t 02 needed for the TV signal to travel from TV transmitter 250 to RT 220 , can be calculated as:
- d 02 can be calculated as:
- BS 210 only needs to know the approximate location of RT 220 so that it can group RTs 220 accordingly. In those cases, the method described above is typically satisfactory.
- the accuracy can also be greatly improved by repeating the above-described procedure for two or more different external terrestrial transmitters 250 (e.g., TV transmitters) not associated with the wireless communication network 200 , and then averaging the results to more accurately determine the location of RT 220 .
- two or more different external terrestrial transmitters 250 e.g., TV transmitters
- RT 220 in three-dimensional space can also be calculated by solving the following equation set:
- d 02 2 ( x 0 ⁇ x 2 ) 2 +( y 0 ⁇ y 2 ) 2 +( z 0 ⁇ z 2 ) 2
- d 23 is the distance between RT 220 and a second TV transmitter 250 determined using the procedure described above
- (x 1 , y 1 , z 1 ) is the location of BS 210 in three-dimensional space
- (x 0 , y 0 , z 0 ) is the location of the first TV transmitter 250 in three-dimensional space
- (x 3 , y 3 , z 3 ) is the location of the second TV transmitter 250 in three-dimensional space.
- the procedures described above can be performed for all RTs 220 in wireless communication network 200 so that BS 210 learns the locations of all of the RTs 220 .
- the performance of an unlicensed wireless communication network operating in a frequency band utilized by one or more incumbent transmitters can be enhanced if the locations of the remote terminals of the wireless communication network are known.
- a base station can divide the remote terminals into a plurality of clusters, and assign the remote terminals to the clusters so as to group remote terminals together in each cluster according to their proximity to each other. In that case, techniques such as group scheduling or multiple antenna diversity can be employed.
- Remote terminals in the same geographical area can be made to share the same directionality thereby improving capacity as well as performance.
- FIG. 4 illustrates a wireless communication network 200 comprising BS 210 and RTs 220 , where RTs 220 have been divided into clusters 230 , and each RT 220 is assigned to one of the clusters 230 so as to group RTs 220 together in each cluster 2430 according to their proximity to each other.
- BS 210 can do one or more of the following.
- external terrestrial transmitter 250 can be any external terrestrial transmitter that transmits a signal including some sync or other feature of pattern that is amenable to time-of-arrival detection and whose location is known to BS 210 .
- external terrestrial transmitter 250 comprises a dedicated beacon transmitter transmitting a signal which can be used for clustering together RTs 220 in wireless communication network 200 .
- remote terminals are assigned to clusters according to an incumbent profile measured at each of the remote terminals produced by one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network.
- the location of the external over-the-air transmitter need not be known, and remote terminals are assigned to clusters in order to group together in each cluster remote terminals having similar incumbent profiles.
- each RT 220 makes measurements in each incumbent (e.g., TV) channel of external signals (e.g., TV signals) transmitted by one or more external terrestrial transmitters 250 not associated with the wireless communication network 200 .
- the incumbent profile measurement can be a simple RF signal strength measurement of the frequency spectrum used by wireless communication network 200 .
- more sophisticated measurements may be made based on the detection of a feature of each external signal to provide greater robustness to multipath. In the latter case, beneficially the strength of the detected feature is used. For example, if the incumbent transmitter 250 is nearby (or transmitting at high power), its value will be high, and vice versa.
- each RT 220 constructs an incumbent profile. This incumbent profile is then disseminated to BS 210 (or its proxy) for clustering, as described in further detail below. This process can be repeated periodically.
- FIG. 5 illustrates a frequency spectrum profile measurement, made by an RT 220 , of incumbent transmissions in a frequency band used by wireless communication network. 200 .
- n the number of RTs 220 in wireless communication network 200 ;
- f total number of frequency channels used by wireless communication network 200 that may include an external signal transmitted by an external terrestrial transmitter 250 ;
- k number of clusters 230 into which the RTs 220 are divided;
- i an index for each RT 220 , where 1 ⁇ i ⁇ n;
- j an index of each cluster 230 , where 1 ⁇ i ⁇ k;
- x i a measurement vector for RT 2201 , of size 1*f;
- J a scalar objective function to be minimized
- J* maximum allowed value for scalar objective function (an input value);
- k* minimum number of clusters 230 required for J ⁇ J* (an output value).
- each of the n RTs 220 measures a frequency spectrum profile at its location, as described above, to produce a measurement vector, x 1 .
- k of the measurement vectors x i of the RTs 220 are randomly assigned as trial mean measurement vectors, m j , for the k clusters 230 .
- These k trial mean measurement vectors m j serve as initial guesses as to the actual mean measurement vectors for the k clusters 230 .
- a step 640 for each RT 2201 , it is determined which one of the mean measurement vectors m j is closest to its measurement vector x i , and the RT 2201 is then assigned to the cluster, j, as a trial assignment.
- an “updated” mean measurement vector m j is calculated for each cluster 230 j using the measurement vectors x i (j) for all of the RTs 220 i in that cluster 230 j.
- Steps 640 and 650 are repeated until there is no further change in the values of the mean measurement vectors m j .
- the scalar objective function to be minimized, J is calculated using the mean measurement vectors m j for each cluster 230 j and all of the measurement vectors x i (j) .
- a step 670 the scalar objective function to be minimized, J, is compared to the maximum allowed value for the scalar objective function, J*.
- J* is a pre-selected value based on target performance criteria for the wireless communication network 200 , and may be determined through operational experience.
- step 680 the algorithm increments k by one, and returns to step 630 above, and steps 630 - 670 are repeated.
- k is equal to k*, and the RTs 220 are assigned to the k* clusters 230 so as to group together in each cluster 230 remote terminals 220 having similar incumbent profiles.
- ⁇ x i (j) ⁇ m j ⁇ 2 indicates the distance between the measurement vector x i (j) of RT 220 i , tentatively assigned to cluster 230 j , and its cluster mean m j , in feature space.
- Some of these advantages relate to sharing the spectrum measurement responsibilities within the wireless communication network, and/or to more efficient dissemination of measurement information. If all the remote terminals measure all the channels and disseminate this information over the wireless communication network, the load on the network could be significant. By decimating the number of measurements made, the dissemination overhead is significantly reduced.
- the frequency with which a given channel must be measured for occupation by an incumbent transmitter depends not on the duty cycle of the incumbent transmitter (which may be of the order of a day), but rather on the vacation time period, which may be of the order of a few seconds.
- the vacation time period is defined as the time period by which the wireless communication network must vacate a channel after an incumbent transmitter begins transmitting on that channel.
- each RT does not have to make repeated measurement of the entire available spectrum.
- the base station (or its proxy) can make the optimal distribution of measurements within a network, which involves the following trading off. If too few remote terminals in the wireless communication network make measurements, an incumbent transmitter might be missed. On the other hand, if each remote terminal searches every channel once each vacation time period, the total amount of time it takes to determine which channels are available could be very large. The above-described approach of clustering provides an intelligent tool to make such a trade-off.
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Abstract
In a wireless communication network (200) comprising a base station (210) and a plurality of remote terminals (220), the plurality of remote terminals (220) are divided into a plurality of clusters (230) for communication with the base station (210), and each of the remote terminals (220) is assigned to a cluster (230) based on at least one characteristic, measured by one or more of the remote terminals (220), of one or more external signals transmitted by one or more external terrestrial transmitters (250) not associated with the communication network (200). Accordingly: a parameter of a communication between the base station (210) and each remote terminal (220) may be selected according to the cluster (230) to which each remote terminal (220) belongs; remote terminals (220) within a cluster (230) may be enabled to communicate directly with each other; and/or remote terminals (220) may be selected to perform frequency spectrum profile measurements of the frequency band used by the communication network (200) according to the clusters (230) to which they are assigned.
Description
- This application claims the benefit of U.S. provisional application Ser. No. 60/718,127 filed Sep. 16, 2005, which is incorporated herein in whole by reference.
- This invention pertains to the field of wireless communication networks, and more particularly to a method of clustering devices in a wireless communication network.
- In the United States, the Federal Communications Commission (FCC) has recently released a proposed rulemaking to allow unlicensed wireless communication networks to operate on certain bands presently utilized by other, existing (“incumbent”), radio services, such as broadcast television. The FCC proposed standards to prevent the unlicensed wireless network's transmitting devices from interfering with the incumbent radio services. For example, these unlicensed transmitting devices are required to vacate any channel within a short time period (e.g., a few seconds) after an incumbent transmitter begins operating. One method of insuring that a transmitting device of an unlicensed wireless network vacates a channel when required to do so is for the device to periodically stop transmitting and to “listen” for incumbent transmitters by checking all channels within their operating band(s) for the presence of any transmissions from incumbent transmitters. If the device detects the presence of any incumbent radio transmissions, the device is then required to take appropriate measures (e.g., change channels; reduce power; shut down; etc.) to insure that it does not interfere with the incumbent signal(s).
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FIG. 1 shows an exemplary unlicensedwireless communication network 100 comprising a base station (BS) 110, and a plurality of remote terminals (RTs) 120. In one embodiment,wireless communication network 100 may be a Wireless Regional Area Networks (WRAN). One typical application is broadband service whereRTs 120 are on the consumer side (e.g., broadband modems) while BS 110 belongs to the service provider and servicesmany RTs 120. -
RTs 120 may be fixed or mobile devices. Typically,wireless communication network 100 may have as many as 100 or more RTs operating with BS 110. As shown inFIG. 1 , in general there may be one or more external transmitters 150 (e.g., incumbent television transmitters) not associated withcommunication network 100 transmitting radio signal(s) in the same general geographical area aswireless communication network 100. Furthermore, newexternal transmitters 150 also may begin transmitting at any time, and these new transmitters are also considered incumbents so that their signals must be protected from interference by transmissions from any ofRTs 120 orBS 110. - If
BS 110 and all of theRTs 120 are required to periodically stop transmitting and listen for incumbent transmitters on every possible channel in order to meet the channel vacation requirements, the time required for this checking may be considerable and the frequency may be often, and this can significantly decrease the availability ofwireless communication network 100. - Furthermore,
wireless communication network 100 may operate over an area with a diameter on the order of tens of miles. So it is possible that a first group ofRTs 120 may be located many miles closer to an incumbentexternal transmitter 150 than a second group ofRTs 120. In that case, communication on one or more channels may be forbidden for theRTs 120 in the first group in order to protect the signal of the incumbentexternal transmitter 150, but communication on these same channels may be permissible for the second group ofRTs 120 that are located many miles away from incumbentexternal transmitter 150. Conversely, the second group ofRTs 120 may be located many miles closer than the first group ofRTs 120 to a different, second incumbentexternal transmitter 150, so that communication on one or more different channels may be permissible for the first group ofRTs 120, but forbidden for the second group ofRTs 120. Even though BS 110 may know the locations and frequencies of all of the incumbentexternal transmitters 150 in its operating area, in general BS 110 has no convenient way of knowing whichRTs 120 are located near which incumbentexternal transmitter 150. In that case, it may be forced to disable communication with all of theRTs 120 on all of the channels on which any of the incumbentexternal transmitters 150 are operating. This reduces the efficiency and data capacity of the network. - Additionally, in some cases it would be desirable, and would increase communication efficiency, for
RTs 120 that are located in close proximity to each other to be able to communicate with each other directly, without passing data or messages throughBS 110. However, if theBS 110 and RTs 120 have no convenient way of knowing whichRTs 120 are located in close proximity, it is not practical to enable such direct communications. - Accordingly, it would be desirable to provide a method and means of grouping together remote terminals in a communication network that permits efficient assignment of resources for measuring the frequency spectrum profile of a frequency band used by the communication network. It would also be desirable to provide a method and means of grouping together remote terminals in a communication network that permits a base station to select and tailor one or more parameters of its communication with a remote terminal based on one or more common characteristics of the group to which the remote terminal belongs. It would further be desirable to provide a method and means of grouping together remote terminals in a communication network that facilitates direct communication between remote terminals that are in close geographical proximity to each other. It would still further be desirable to provide a system and method of determining the locations of fixed and mobile remote terminals in a wireless communication network.
- In one aspect of the invention, in a wireless communication network comprising a base station and a plurality of remote terminals, a method of communication comprises dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on at least one characteristic, measured by one or more of the remote terminals, of one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network; and selecting at least one parameter of a communication between the base station and each remote terminal according to a cluster to which each remote terminal belongs.
- In another aspect of the invention, in a wireless communication network comprising a base station and a plurality of remote terminals, a method of communication comprises determining a location of each of the plurality of remote terminals with respect to the base station; dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on the determined location of each remote terminal so as to group remote terminals together in each cluster according to their proximity to each other; and selecting at least one parameter of a communication between the base station and each remote terminal according to a cluster to which each remote terminal belongs.
- In a further aspect of the invention, in a wireless communication network comprising a base station and a plurality of remote terminals, a method of determining a location of each of the plurality of remote terminals with respect to the base station comprises: (a) determining a distance, d12, between the base station and the remote terminal, based on a turnaround time interval, t12, for a token to be transmitted roundtrip between the base station and the remote terminal; (b) determining a time of arrival, t1, at the base station of a sync signal included in an external signal transmitted by an external terrestrial transmitter not associated with the wireless communication network and located at a known location; (c) determining a time interval, t02, for the external signal to travel from the external terrestrial transmitter to the remote terminal using: (1) a known distance d01 between the base station and the external terrestrial transmitter, (2) the time of arrival t1, and (3) a time of arrival, t2, at the remote terminal of the sync signal included in the external signal transmitted by the external terrestrial transmitter not associated with the wireless communication network; (d) determining a distance, d02, between the remote terminal and the known location of the external terrestrial transmitter, based on the time interval t02; and (e) determining the location of the remote terminal using: (1) the distances d12 and d02, (2) the known location of the external terrestrial transmitter, and (3) a known location of the base station.
- In still another aspect of the invention, in a wireless communication network comprising a base station and a plurality of remote terminals, a method of communication comprises dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on at least one characteristic, measured by one or more of the remote terminals, of one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network; and enabling each remote terminal to communicate data directly with other remote terminals in its assigned cluster without passing the data through the base station.
- In yet another aspect of the invention, in a wireless communication network comprising a base station and a plurality of remote terminals, a method of communication comprises dividing the plurality of remote terminals into a plurality of clusters for communication with the base station; assigning each of the remote terminals to one of the clusters based on at least one characteristic, measured by one or more of the remote terminals, of one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network; and selecting which ones among the plurality of remote terminals will perform frequency spectrum profile measurements of a frequency band used by the external terrestrial transmitters not associated with the wireless communication network, according to the clusters to which they are assigned.
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FIG. 1 shows a wireless communication network; -
FIG. 2 illustrates a wireless communication network including remote terminals divided into clusters; -
FIG. 3 shows a diagram for explaining a method of determining the location of a remote terminal in a wireless communication network; -
FIG. 4 illustrates a wireless communication network where remote terminals are divided into clusters based on geographical proximity to each other; -
FIG. 5 illustrates a frequency spectrum profile measurement of incumbent transmissions in a frequency band used by a communication network; and -
FIG. 6 shows a flowchart of a method of dividing remote terminals into clusters, and assigning the remote terminals to the clusters, in a wireless communication network. - While various principles and features of the methods and systems described below can be applied to a variety of communication systems, for illustration purposes the exemplary embodiments below will be described in the context of an unlicensed wireless communication network, such as that described above, that operates in one or more frequency bands that are populated with incumbent transmitters. Of course, the scope of the invention is defined by the claims appended hereto, and is not limited by the particular embodiments described below. Furthermore, as used herein, the term “an external terrestrial transmitter not associated with the wireless communication network” refers to any terrestrial radio transmitter that transmits its signal independently of the operation of the wireless communication network, for example: a terrestrial analog or digital television broadcast transmitter; a television relay transmitter; a terrestrial commercial radio broadcast transmitter; a radio repeater in the public service or amateur radio bands; etc.
- Disclosed herein is a method of communication for a wireless communication network comprising a base station and a plurality of remote terminals. The method divides the plurality of remote terminals into a plurality of clusters for communication with the base station, and assigns each of the remote terminals to one of the clusters.
-
FIG. 2 illustrates awireless communication network 200 including a base station (BS) 210 and a plurality of remote terminals (RTs) 220 divided intoclusters 230. - As described in further detail below, each of the
RTs 220 is assigned to one of theclusters 230 based on at least one characteristic, measured by one or more of theRTs 220, of one or more external signals transmitted by one or more externalterrestrial transmitters 250 not associated with thewireless communication network 200. - In one embodiment, the measured characteristic is a time of arrival at an
RT 220 of a sync signal included in an external signal transmitted by the externalterrestrial transmitter 250. For example, where the externalterrestrial transmitter 250 is a digital television (DTV) transmitter, the sync signal may be a field sync sequence in the DTV broadcast signal. In that case, the measured time of arrival of the sync sequence atRT 220 is used to calculate the location of theRT 220, which is in turn used to assignRT 220 to aparticular cluster 230. - In another embodiment, the measured characteristic is “profile” of incumbent transmissions from all of the external
terrestrial transmitters 250 that are received at each of theRTs 220. Beneficially, the incumbent profile may be a frequency spectrum profile, measured at each of theRTs 220, produced by the external signals from the externalterrestrial transmitters 250. In that case,RTs 220 are assigned toclusters 230 in order to group together in eachcluster 230RTs 220 having similar incumbent (e.g., frequency spectrum) profiles. - In accordance with a first embodiment,
FIG. 3 shows a diagram for explaining a method of determining the location of a remote terminal in a wireless communication network based on a time of arrival of an external signal transmitted by one or more external terrestrial transmitters not associated with the wireless communication network.FIG. 3 shows a base station (BS) 210, a remote terminal (RT) 220, and an external terrestrial transmitter 250 (e.g., a terrestrial broadcast television (TV) transmitter) not associated with thewireless communication network 200. - The location (x1, y1) of BS 210 is assumed to be known. The location (x0, y0) of external
terrestrial transmitter 250 is also assumed to be known (a record of the location of TV transmitters in the United States is maintained by the FCC). Thus, the distance d01 betweenTV transmitter 250 and BS 210 can be calculated and stored in BS 210. Additionally, the locations of BS 210 andTV transmitter 250 can be separately stored in BS 210. - Additionally, BS 210 may determine the distance d12 between the
RT 220 and itself in the following way. First, BS 210 transmits a token toRT 220 and requests that RT 220 respond back to BS 210. The turnaround time, tRT, to receive the response fromRT 220, minus any processing time, can be used to calculate the distance d12 between theBS 210 andRT 220 according to the following equation: -
- where c is the speed of light.
- Next, the distance d02 between the
TV transmitter 250 andRT 220 is determined as follows. - A terrestrial television broadcast signal typically contains a known synchronization signal. For example, in the United States a terrestrial digital television (DTV) broadcast signal has a certain repetitive structure. A terrestrial DTV transmitter in the United States transmits a known signal (called a “frame sync”) every 24.2 ms.
- This known signal can be used to compute the distance d02 between
TV station 250 andRT 220, as follows. First,BS 210 instructsST 220 to search for the sync sequence in a television signal transmitted byTV transmitter 250. The time of arrival, t2, of the sync sequence atRT 220 is determined. Meanwhile,BS 210 also searches for the sync sequence in the TV signal transmitted byTV transmitter 250, and records the time of arrival, t1, of the sync sequence at its location. In that case, the time interval, t02, needed for the TV signal to travel fromTV transmitter 250 toRT 220, can be calculated as: -
t 02 =t 2−(t 1 −d 01 /c) (2) - Once t02 is known, then d02 can be calculated as:
-
d 02 =c*t 02 (3) - Now that d02 and d12 have been calculated as described above, one can determine the location (x2, y2) of
RT 220 by solving the following pair of simultaneous equations: -
d 02 2=(x 0 −x 2)2+(y 0 −y 2)2 -
d 12 2=(x 1 −x 2)+(y 1 −y 2) (4) - Except for x2 and y2, all of the other variables in the equation pair (4) are known. So by simultaneously solving the equation pair, the location (x2, y2) of
RT 220 can be found. - Meanwhile, a number of factors may negatively impact the accuracy of the location determination method described above. For example, multipath and clock mismatches may affect the accuracy of the time-of-arrival measurements. Fortunately, for broadband wireless communication network applications, a high degree of accuracy is not required. In such an application,
BS 210 only needs to know the approximate location ofRT 220 so that it can groupRTs 220 accordingly. In those cases, the method described above is typically satisfactory. - In those circumstances where a more accurate determination of the location of
RT 220 is needed, the accuracy can also be greatly improved by repeating the above-described procedure for two or more different external terrestrial transmitters 250 (e.g., TV transmitters) not associated with thewireless communication network 200, and then averaging the results to more accurately determine the location ofRT 220. - Furthermore, if signals transmitted by two or more different external terrestrial transmitters 250 (e.g., TV transmitters) not associated with
wireless communication network 200 are available, then the location ofRT 220 in three-dimensional space (x2, y2, z2) can also be calculated by solving the following equation set: -
d 02 2=(x 0 −x 2)2+(y 0 −y 2)2+(z 0 −z 2)2 -
d 12 2=(x 1 −x 2)2+(y 1 −y 2)2+(z 1−z2)2 -
d 23 2=(x 3 −x 2)2+(y 3 −y 2)2+(z 3 −z 2)2 (5) - where d23 is the distance between
RT 220 and asecond TV transmitter 250 determined using the procedure described above, (x1, y1, z1) is the location ofBS 210 in three-dimensional space, (x0, y0, z0) is the location of thefirst TV transmitter 250 in three-dimensional space, and (x3, y3, z3) is the location of thesecond TV transmitter 250 in three-dimensional space. - The procedures described above can be performed for all
RTs 220 inwireless communication network 200 so thatBS 210 learns the locations of all of theRTs 220. - The performance of an unlicensed wireless communication network operating in a frequency band utilized by one or more incumbent transmitters can be enhanced if the locations of the remote terminals of the wireless communication network are known. When the locations are known, a base station can divide the remote terminals into a plurality of clusters, and assign the remote terminals to the clusters so as to group remote terminals together in each cluster according to their proximity to each other. In that case, techniques such as group scheduling or multiple antenna diversity can be employed. Remote terminals in the same geographical area can be made to share the same directionality thereby improving capacity as well as performance.
-
FIG. 4 illustrates awireless communication network 200 comprisingBS 210 andRTs 220, whereRTs 220 have been divided intoclusters 230, and eachRT 220 is assigned to one of theclusters 230 so as togroup RTs 220 together in each cluster 2430 according to their proximity to each other. - By
clustering RTs 220 together according to their geographical proximity,BS 210 can do one or more of the following. -
-
BS 210 can select at least one parameter of communication betweenBS 210 and eachRT 220 according to theparticular cluster 230 to which thatRT 220 belongs. For example,BS 210 may select different modulation and/or error correction coding formats fordifferent clusters 230 ofRTs 220 depending upon the general location of thecluster 230. That is,BS 210 may select a more robust coding/modulation format forclusters 230 ofRTs 220 that are distant fromBS 210, or forclusters 230 ofRTs 220 that are located close to an externalterrestrial transmitter 250 not associated with thewireless communication network 200, and which therefore experience increased interference. Furthermore,BS 210 may optimize the guard interval when a multi-carrier scheme such as orthogonal frequency division multiplexing (OFDM) is employed, according to the expected multipath delay spread of aparticular cluster 230. Thus, clustering allowsBS 210 to tailor one or more parameters of its communication with anRT 220 based on one or more common characteristics of thecluster 230 to which theRT 220 belongs. -
BS 210 can use a directional antenna in combination with techniques such as space division multiplexing betweenclusters 230. This can increase the overall capacity of thewireless communication network 200, sinceRTs 220 that are not in thesame cluster 230 can transmit and receive at the same time with little interference. Also,BS 210 may use different frequency channels to communicate withdifferent clusters 230 ofRTs 220 depending upon the relative locations ofincumbent transmitters 250. That is, it may be possible forBS 210 to use a first frequency channel for communication with afirst cluster 230, while it is not permitted to use that same first frequency channel for communication with asecond cluster 230 because of the proximity of thesecond cluster 230 to anincumbent transmitter 250 operating on the first frequency channel. At the same time,BS 210 may be able to use a second frequency channel to communicate with thesecond cluster 230, while it is not permitted to use that channel for communication with thefirst cluster 230 because of the proximity of thefirst cluster 230 to a secondincumbent transmitter 250 operating on the second frequency channel. Thus, clustering allowsBS 210 to more efficiently utilize its communication resources in communicating with a plurality ofRTs 220. -
BS 210 can scheduleRTs 220 in acluster 230 to communicate directly with each other, without having to pass messages or data throughBS 210. This can produce a multi-sensor network that can be used for applications other than broadband service.
-
- Although for ease of explanation, in the discussion above the external
terrestrial transmitter 250 was described in terms of a terrestrial broadcast television (TV) transmitter, in practice externalterrestrial transmitter 250 can be any external terrestrial transmitter that transmits a signal including some sync or other feature of pattern that is amenable to time-of-arrival detection and whose location is known toBS 210. In one embodiment, externalterrestrial transmitter 250 comprises a dedicated beacon transmitter transmitting a signal which can be used for clustering togetherRTs 220 inwireless communication network 200. - Although a process of clustering remote terminals in a wireless communication network has been described above based on determining a geographical location of each remote terminal, in another embodiment remote terminals are assigned to clusters according to an incumbent profile measured at each of the remote terminals produced by one or more external signals transmitted by one or more external terrestrial transmitters not associated with the wireless communication network. In that case, the location of the external over-the-air transmitter need not be known, and remote terminals are assigned to clusters in order to group together in each cluster remote terminals having similar incumbent profiles.
- According to this embodiment, each
RT 220 makes measurements in each incumbent (e.g., TV) channel of external signals (e.g., TV signals) transmitted by one or more externalterrestrial transmitters 250 not associated with thewireless communication network 200. The incumbent profile measurement can be a simple RF signal strength measurement of the frequency spectrum used bywireless communication network 200. Alternatively, more sophisticated measurements may be made based on the detection of a feature of each external signal to provide greater robustness to multipath. In the latter case, beneficially the strength of the detected feature is used. For example, if theincumbent transmitter 250 is nearby (or transmitting at high power), its value will be high, and vice versa. Based on these measurements, eachRT 220 constructs an incumbent profile. This incumbent profile is then disseminated to BS 210 (or its proxy) for clustering, as described in further detail below. This process can be repeated periodically. -
FIG. 5 illustrates a frequency spectrum profile measurement, made by anRT 220, of incumbent transmissions in a frequency band used by wireless communication network. 200. - Next, an algorithm is described for clustering together
RTs 220 having similar incumbent profiles will be described with respect to the flowchart ofFIG. 6 . - At the outset, we define a number of variables as follows:
- n=the number of
RTs 220 inwireless communication network 200; - f=total number of frequency channels used by
wireless communication network 200 that may include an external signal transmitted by an externalterrestrial transmitter 250; - k=number of
clusters 230 into which theRTs 220 are divided; - i=an index for each
RT 220, where 1≦i≦n; and - j=an index of each
cluster 230, where 1≦i≦k; -
xi =a measurement vector for RT 2201, of size 1*f; - J=a scalar objective function to be minimized;
- J*=maximum allowed value for scalar objective function (an input value);
- k*=minimum number of
clusters 230 required for J≦J* (an output value). - Turning again to
FIG. 6 , the algorithm proceeds as follows. - In a
step 610, the number ofclusters 230 is set to two (2) (k=2). - Meanwhile, in a
step 620 each of then RTs 220 measures a frequency spectrum profile at its location, as described above, to produce a measurement vector,x1 . - Then, in a
step 630, k of the measurement vectorsxi of theRTs 220 are randomly assigned as trial mean measurement vectors,mj , for thek clusters 230. These k trial mean measurement vectorsmj serve as initial guesses as to the actual mean measurement vectors for thek clusters 230. - Next, in a
step 640, for each RT 2201, it is determined which one of the mean measurement vectorsmj is closest to its measurement vectorxi , and the RT 2201 is then assigned to the cluster, j, as a trial assignment. - After all of the
RTs 220 have been assigned to one of thek clusters 230, in astep 650 an “updated” mean measurement vectormj is calculated for each cluster 230 j using the measurement vectors xi (j) for all of the RTs 220 i in that cluster 230 j. -
Steps mj . - Next, in a
step 660, the scalar objective function to be minimized, J, is calculated using the mean measurement vectorsmj for each cluster 230 j and all of the measurement vectorsxi (j) . - In a
step 670, the scalar objective function to be minimized, J, is compared to the maximum allowed value for the scalar objective function, J*. J* is a pre-selected value based on target performance criteria for thewireless communication network 200, and may be determined through operational experience. - If J>J*, then in a
step 680, the algorithm increments k by one, and returns to step 630 above, and steps 630-670 are repeated. - If J≦J*, then the algorithm ends. At that point, k is equal to k*, and the
RTs 220 are assigned to the k*clusters 230 so as to group together in eachcluster 230remote terminals 220 having similar incumbent profiles. - Mathematically, one beneficial selection for the scalar function, J, is:
-
- where ∥
xi (j) −m j∥2 indicates the distance between the measurement vectorxi (j) of RT 220 i, tentatively assigned to cluster 230 j, and its cluster meanmj , in feature space. - There are a number of advantages of clustering remote terminals. Some of these advantages relate to sharing the spectrum measurement responsibilities within the wireless communication network, and/or to more efficient dissemination of measurement information. If all the remote terminals measure all the channels and disseminate this information over the wireless communication network, the load on the network could be significant. By decimating the number of measurements made, the dissemination overhead is significantly reduced.
- In this regard, it is noted that the frequency with which a given channel must be measured for occupation by an incumbent transmitter depends not on the duty cycle of the incumbent transmitter (which may be of the order of a day), but rather on the vacation time period, which may be of the order of a few seconds. The vacation time period is defined as the time period by which the wireless communication network must vacate a channel after an incumbent transmitter begins transmitting on that channel. When the vacation time period is small, unless information dissemination overhead is efficiently managed, it could become significant part of the total available radio resources. This is especially true if contention-based access mechanisms are used to disseminate measurement information.
- However, once remote terminals are clustered together based on similar incumbent profiles, each RT does not have to make repeated measurement of the entire available spectrum. The base station (or its proxy) can make the optimal distribution of measurements within a network, which involves the following trading off. If too few remote terminals in the wireless communication network make measurements, an incumbent transmitter might be missed. On the other hand, if each remote terminal searches every channel once each vacation time period, the total amount of time it takes to determine which channels are available could be very large. The above-described approach of clustering provides an intelligent tool to make such a trade-off.
- While preferred embodiments are disclosed herein, many variations are possible which remain within the concept and scope of the invention. Such variations would become clear to one of ordinary skill in the art after inspection of the specification, drawings and claims herein. The invention therefore is not to be restricted except within the spirit and scope of the appended claims.
Claims (20)
1. In a wireless communication network (200) comprising a base station (210) and a plurality of remote terminals (220), a method of communication, comprising:
dividing the plurality of remote terminals (220) into a plurality of clusters (230) for communication with the base station (210);
assigning each of the remote terminals (220) to one of the clusters (230) based on at least one characteristic, measured by one or more of the remote terminals (220), of one or more external signals transmitted by one or more external terrestrial transmitters (250) not associated with the wireless communication network (200); and
performing at least one of the following three operations:
(1) selecting, according to a cluster (230) to which each remote terminal (220) belongs, at least one parameter of a communication between the base station (210) and each remote terminal (220);
(2) selecting, according to the clusters (230) to which they are assigned, which ones among the plurality of remote terminals (220) will perform frequency spectrum profile measurements of a frequency band used by the external terrestrial transmitters (250) not associated with the wireless communication network (200); and
(3) selecting, according to the clusters (230) to which they are assigned, which ones among the plurality of remote terminals (220) will transmit to the base station (210) frequency spectrum profile measurements of a frequency band used by the external terrestrial transmitters (250) not associated with the wireless communication network (200).
2. The method of claim 1 , wherein the at least one characteristic measured by the one or more remote terminals (220) comprises a frequency spectrum profile measured at each of the remote terminals (220) produced by the one or more external signals transmitted by the one or more external terrestrial transmitters (250) not associated with the wireless communication network (200).
3. The method of claim 2 , wherein the frequency spectrum profile comprises a measurement vector, xi , of size 1*f where f is a number of channels assigned for defining the external signals transmitted by the one or more external terrestrial transmitters (250), where i is an index number of a corresponding remote terminal (220), and where j is an index number of a cluster (230).
4. The method of claim 3 , wherein the plurality of remote terminals (220) is n, and wherein dividing the n remote terminals (220) into a plurality of clusters (230) for communication with the base station (210) and assigning each of the n remote terminals (220) to one of the clusters (230) based on the measured characteristic of the one or more external signals comprises:
(610) establishing a trial value of k=2 clusters (230);
(630) assigning k of the n measurement vectors of the n remote terminals (220) as trial mean measurement vectors, mj , for each of the k clusters (230);
(640) for each of the n remote terminals (220), determining which of the trial mean measurement vectors, mj , is closest to its measurement vector xi and tentatively assigning the remote terminal (220) to the corresponding cluster (230) j as a tentative assignment;
(650) for each cluster (230), j, calculating a new mean measurement vector mj using the measurement vectors for all of the remote terminals (220) tentatively assigned to the cluster (230) j in step (640);
repeating steps (640) and (650) until there is no change in the values of the mean measurement vectors mj ;
(660) computing a total vector distance, J, between the measurement vectors xi for each of the n remote terminals (220) and the mean vector mj for the cluster (230) j to which the remote terminal (220) was last tentatively assigned in step (640);
(670) comparing J to a maximum allowed value J*;
(680) when J is greater than the maximum allowed value J*; incrementing k by 1 and repeating steps (630) through (670) until J is less than or equal to the maximum allowed value J*; and
when J is less than or equal to the maximum allowed value J*; using the trial value of k as a number of clusters (230) into which the n remote terminals (220) are divided, and using the tentative assignments of step (c) to assign each of the n remote terminals (220) to one of the k clusters (230).
5. The method of claim 1 , wherein the at least one parameter of the communication between the base station (210) and the remote terminal (220) that is selected according to a cluster (230) to which the remote terminal (220) belongs comprises at least one selected from the group consisting of: an error correction code, a modulation format, a guard interval between adjacent transmitted symbols, and one or more frequency channels.
6. The method of claim 1 , wherein the at least one characteristic of the one or more external signals measured by the one or more remote terminals (220) comprises a time of arrival of a sync signal included in at least one of the one or more external signals transmitted by the one or more external terrestrial transmitters (250) not associated with the wireless communication network (200).
7. The method of claim 6 , wherein the sync signal is a field sync sequence in a digital television (DTV) broadcast signal.
8. The method of claim 1 , wherein the one or more external signals transmitted by the one or more external terrestrial transmitters (250) not associated with the wireless communication network (200) includes a television broadcast signal in a frequency channel in which the wireless communication network (200) operates.
9. In a wireless communication network (200) comprising a base station (210) and a plurality of remote terminals (220), a method of communication, comprising:
determining a location of each of the plurality of remote terminals (220) with respect to the base station (210);
dividing the plurality of remote terminals (220) into a plurality of clusters (230) for communication with the base station (210);
assigning each of the remote terminals (220) to one of the clusters (230) based on the determined location of each remote terminal (220) so as to group remote terminals (220) together in each cluster (230) according to their proximity to each other; and
selecting at least one parameter of a communication between the base station (210) and each remote terminal (220) according to a cluster (230) to which each remote terminal (220) belongs.
10. The method of claim 9 , wherein determining a location of each of the plurality of remote terminals (220) with respect to the base station (210), comprises, for each remote terminal (220):
determining a distance, d12, between the base station (210) and the remote terminal (220);
determining a distance, d02, between the remote terminal (220) and a known location of a television broadcast antenna; and
solving a pair of simultaneous equations using: (1) the distances d12 and d02, (2) the known location of the television broadcast antenna, and (3) a known location of the base station (210), to determine the location of the remote terminal (220).
11. The method of claim 10 , wherein determining the distance, d12, between the base station (210) and the remote terminal (220) comprises:
measuring a turnaround time interval, t12, for a token to be transmitted roundtrip between the base station (210) and the remote terminal (220); and
determining the distance, d12, from the turnaround time interval, t12.
12. The method of claim 10 , wherein determining the distance, d02, between the known location of the television broadcast antenna and the remote terminal (220), comprises:
determining a time of arrival, t1, at the base station (210) of a sync signal included in a television signal transmitted by the television broadcast antenna;
determining a time of arrival, t2, at the remote terminal (220) of the sync signal included in the television signal transmitted by the television broadcast antenna;
determining a time interval, to 2, for the television signal to travel from the television broadcast antenna to the remote terminal (220) using the times of arrival t1 and t2 and a known distance d01 between the base station (210) and the television broadcast antenna; and
determining d02 according to the equation d02=t02*c, where c is the speed of light.
13. The method of claim 12 , wherein the television signal is in a frequency channel in which the wireless communication network (200) operates.
14. The method of claim 9 , wherein the at least one parameter of the communication between the base station (210) and the remote terminal (220) that is selected according to a cluster (230) to which the remote terminal (220) belongs comprises at least one selected from the group consisting of: an error correction code, a modulation format, a guard interval between adjacent transmitted symbols, and one or more frequency channels.
15. In a wireless communication network (200) comprising a base station (210) and a plurality of remote terminals (220), a method of determining a location of each of the plurality of remote terminals (220) with respect to the base station (210), comprising:
(a) determining a distance, d12, between the base station (210) and the remote terminal (220), based on a turnaround time interval, t12, for a token to be transmitted roundtrip between the base station (210) and the remote terminal (220);
(b) determining a time of arrival, t1, at the base station (210) of a sync signal included in an external signal transmitted by an external terrestrial transmitter (250) located at a known location;
(c) determining a time interval, t02, for the external signal to travel from the external terrestrial transmitter (250) to the remote terminal (220) using: (1) a known distance d01 between the base station (210) and the external terrestrial transmitter (250), (2) the time of arrival t1, and (3) a time of arrival, t2, at the remote terminal (220) of the sync signal included in the external signal transmitted by the external terrestrial transmitter (250);
(d) determining a distance, d02, between the remote terminal (220) and the known location of the external terrestrial transmitter (250), based on the time interval to 2; and
(e) determining the location of the remote terminal (220) using: (1) the distances d12 and d02, (2) the known location of the external terrestrial transmitter (250), and (3) a known location of the base station (210).
16. The method of claim 15 , wherein the external terrestrial transmitter (250) is a television broadcast transmitter (250) and the external signal is a television signal in a frequency channel in which the wireless communication network (200) operates.
17. The method of claim 15 , further comprising:
(f) determining a time of arrival, t3, at the base station (210) of a sync signal included in a second external signal transmitted by a second external terrestrial transmitter (250) not associated with the wireless communication network (200) located at a known location;
(g) determining a time interval, t23, for the external signal to travel from the second external terrestrial transmitter (250) to the remote terminal (220) using: (1) the known distance d13 between the base station (210) and the second external terrestrial transmitter (250), (2) the time of arrival t3, and (3) a time of arrival, t4, at the remote terminal (220) of the sync signal included in the second external signal transmitted by the second external terrestrial transmitter (250) not associated with the wireless communication network (200);
(h) determining a distance, d23, between the remote terminal (220) and a known location of the second external terrestrial transmitter (250), based on the time interval t23;
(i) determining the location of the remote terminal (220) using: (1) the distances d12 and d23, (2) the known location of the second external terrestrial transmitter (250), and (3) the known location of the base station (210); and
(j) averaging the locations produced in steps (e) and (i) using the first and second external signals transmitted by the first and second external terrestrial transmitters (250) to more accurately determine the location of the remote terminal (220).
18. The method of claim 15 , further comprising:
determining a time of arrival, t3, at the base station (210) of a sync signal included in a second external signal transmitted by a second external terrestrial transmitter (250) not associated with the wireless communication network (200), located at a second known location;
determining a time interval, t23, for the external signal to travel from the second external terrestrial transmitter (250) to the remote terminal (220) using: (1) the known distance d13 between the base station (210) and the second external terrestrial transmitter (250), (2) the time of arrival t3, and (3) a time of arrival, t4, at the remote terminal (220) of the sync signal included in the second external signal transmitted by the second external terrestrial transmitter (250) not associated with the wireless communication network (200); and
determining a distance, d23, from the known location of second external terrestrial transmitter (250) to the remote terminal (220) based on the time interval t13,
wherein determining the location of the remote terminal (220) using: (1) the distances d12 and d02, (2) the known location of the external terrestrial transmitter (250); and (3) the known location of the base station (210), further comprises determining the location of the remote terminal (220) in three dimensions by further using (4) the known location of the second external terrestrial transmitter (250); and (5) the distance d23.
19. In a wireless communication network (200) comprising a base station (210) and a plurality of remote terminals (220), a method of communication, comprising:
dividing the plurality of remote terminals (220) into a plurality of clusters (230) for communication with the base station (210);
assigning each of the remote terminals (220) to one of the clusters (230) based on at least one characteristic, measured by one or more of the remote terminals (220), of one or more external signals transmitted by one or more external terrestrial transmitters (250) not associated with the wireless communication network (200); and
enabling each remote terminal (220) to communicate data directly with other remote terminals (220) in its assigned cluster (230) without passing the data through the base station (210).
20. In a wireless communication network (200) comprising a base station (210) and a plurality of remote terminals (220), a method of communication, comprising:
dividing the plurality of remote terminals (220) into a plurality of clusters (230) for communication with the base station (210);
assigning each of the remote terminals (220) to one of the clusters (230) based on at least one characteristic, measured by one or more of the remote terminals (220), of one or more external signals transmitted by one or more external terrestrial transmitters (250) not associated with the wireless communication network (200); and
selecting which ones among the plurality of remote terminals (220) will perform frequency spectrum profile measurements of a frequency band used by the external terrestrial transmitters (250) not associated with the wireless communication network (200), according to the clusters (230) to which they are assigned.
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CN (7) | CN101310548B (en) |
AT (1) | ATE453298T1 (en) |
DE (1) | DE602006011346D1 (en) |
WO (1) | WO2007031956A2 (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090028077A1 (en) * | 2007-07-23 | 2009-01-29 | Jennic Ltd. | Method of determining the location of a node in a distributed wireless sensor and actuator network |
US20090219944A1 (en) * | 2005-11-07 | 2009-09-03 | Ying Chang Liang | Methods and devices for allocating frequency ranges |
US20090252096A1 (en) * | 2005-11-07 | 2009-10-08 | Thmpson Licensing | Apparatus and Method for Dynamic Frequency Selection in Wireless Networks |
US20090298522A1 (en) * | 2008-05-30 | 2009-12-03 | Motorola, Inc. | Coexistence and incumbent protection in a cognitive radio network |
US20090296000A1 (en) * | 2008-05-30 | 2009-12-03 | Echostar Technologies L.L.C. | Systems, methods and apparatus for exchanging data between television receivers over a wireless communication link |
US20110080878A1 (en) * | 2009-07-03 | 2011-04-07 | Robert Novak | Method for control signaling for group of users using ms assignment index |
US20130016671A1 (en) * | 2011-01-17 | 2013-01-17 | Hao-Chung Cheng | Method of Handling Coordinated Scheduling for Base Stations and Mobile Devices and Related Communication Device |
US9363724B2 (en) | 2009-04-06 | 2016-06-07 | Interdigital Patent Holdings, Inc. | Television band (TVBD) channel quieting across diverse radio access technologies |
US9661598B2 (en) * | 2015-09-30 | 2017-05-23 | Mitsubishi Electric Research Laboratories, Inc. | System and method for reducing interference between multiple terminals |
US10678353B2 (en) | 2015-12-28 | 2020-06-09 | Fuji Xerox Co., Ltd. | Electronic apparatus for communication between electronic pen and external device |
US11363615B2 (en) * | 2014-05-22 | 2022-06-14 | Kyocera Corporation | Assignment of communication resources in an unlicensed frequency band to equipment operating in a licensed frequency band |
Families Citing this family (88)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9544860B2 (en) | 2003-02-24 | 2017-01-10 | Qualcomm Incorporated | Pilot signals for use in multi-sector cells |
US8811348B2 (en) | 2003-02-24 | 2014-08-19 | Qualcomm Incorporated | Methods and apparatus for generating, communicating, and/or using information relating to self-noise |
US9661519B2 (en) | 2003-02-24 | 2017-05-23 | Qualcomm Incorporated | Efficient reporting of information in a wireless communication system |
US7218948B2 (en) | 2003-02-24 | 2007-05-15 | Qualcomm Incorporated | Method of transmitting pilot tones in a multi-sector cell, including null pilot tones, for generating channel quality indicators |
US8503938B2 (en) | 2004-10-14 | 2013-08-06 | Qualcomm Incorporated | Methods and apparatus for determining, communicating and using information including loading factors which can be used for interference control purposes |
WO2006044718A2 (en) | 2004-10-14 | 2006-04-27 | Flarion Technologies, Inc. | Methods and apparatus for determining, communicating and using information which can be used for interference control purposes |
US7742444B2 (en) | 2005-03-15 | 2010-06-22 | Qualcomm Incorporated | Multiple other sector information combining for power control in a wireless communication system |
US8750908B2 (en) | 2005-06-16 | 2014-06-10 | Qualcomm Incorporated | Quick paging channel with reduced probability of missed page |
US9055552B2 (en) | 2005-06-16 | 2015-06-09 | Qualcomm Incorporated | Quick paging channel with reduced probability of missed page |
US8989084B2 (en) | 2005-10-14 | 2015-03-24 | Qualcomm Incorporated | Methods and apparatus for broadcasting loading information corresponding to neighboring base stations |
KR100785799B1 (en) * | 2005-10-14 | 2007-12-13 | 한국전자통신연구원 | Method of Frequency Channel Assignment using Effective Spectrum Sensing in multiple FA system |
US9191840B2 (en) | 2005-10-14 | 2015-11-17 | Qualcomm Incorporated | Methods and apparatus for determining, communicating and using information which can be used for interference control |
US20090207790A1 (en) | 2005-10-27 | 2009-08-20 | Qualcomm Incorporated | Method and apparatus for settingtuneawaystatus in an open state in wireless communication system |
WO2007050983A1 (en) | 2005-10-27 | 2007-05-03 | Qualcomm Incorporated | A method and apparatus for transmitting and receiving mcwflab1 over f-ssch in wireless communication system |
US9451491B2 (en) | 2005-12-22 | 2016-09-20 | Qualcomm Incorporated | Methods and apparatus relating to generating and transmitting initial and additional control information report sets in a wireless system |
US8514771B2 (en) | 2005-12-22 | 2013-08-20 | Qualcomm Incorporated | Methods and apparatus for communicating and/or using transmission power information |
US8437251B2 (en) | 2005-12-22 | 2013-05-07 | Qualcomm Incorporated | Methods and apparatus for communicating transmission backlog information |
US9338767B2 (en) | 2005-12-22 | 2016-05-10 | Qualcomm Incorporated | Methods and apparatus of implementing and/or using a dedicated control channel |
US9125092B2 (en) | 2005-12-22 | 2015-09-01 | Qualcomm Incorporated | Methods and apparatus for reporting and/or using control information |
US20070249360A1 (en) | 2005-12-22 | 2007-10-25 | Arnab Das | Methods and aparatus related to determining, communicating, and/or using delay information in a wireless communications system |
US9137072B2 (en) | 2005-12-22 | 2015-09-15 | Qualcomm Incorporated | Methods and apparatus for communicating control information |
US9119220B2 (en) | 2005-12-22 | 2015-08-25 | Qualcomm Incorporated | Methods and apparatus for communicating backlog related information |
US9148795B2 (en) | 2005-12-22 | 2015-09-29 | Qualcomm Incorporated | Methods and apparatus for flexible reporting of control information |
US9473265B2 (en) | 2005-12-22 | 2016-10-18 | Qualcomm Incorporated | Methods and apparatus for communicating information utilizing a plurality of dictionaries |
US9572179B2 (en) | 2005-12-22 | 2017-02-14 | Qualcomm Incorporated | Methods and apparatus for communicating transmission backlog information |
US9125093B2 (en) | 2005-12-22 | 2015-09-01 | Qualcomm Incorporated | Methods and apparatus related to custom control channel reporting formats |
US20070149132A1 (en) | 2005-12-22 | 2007-06-28 | Junyl Li | Methods and apparatus related to selecting control channel reporting formats |
US20070243882A1 (en) | 2006-04-12 | 2007-10-18 | Qualcomm Incorporated | Method and apparatus for locating a wireless local area network associated with a wireless wide area network |
US7570927B2 (en) * | 2006-06-16 | 2009-08-04 | Motorola, Inc. | Decentralized wireless communication network and method having a plurality of devices |
KR101145847B1 (en) * | 2006-07-14 | 2012-05-17 | 삼성전자주식회사 | Signalling method of detecting hidden incumbent system in cognitive radio environment and channel fractioning method used to enable the method |
US8254922B2 (en) * | 2006-10-16 | 2012-08-28 | Stmicroelectronics, Inc. | Zero delay frequency switching with dynamic frequency hopping for cognitive radio based dynamic spectrum access network systems |
US8494546B2 (en) | 2006-10-16 | 2013-07-23 | Stmicroelectronics, Inc. | Method of inter-system communications dynamic spectrum access network systems-logical control connections |
US7869400B2 (en) * | 2006-10-16 | 2011-01-11 | Stmicroelectronics, Inc. | Method of inter-system coexistence and spectrum sharing for dynamic spectrum access networks-on-demand spectrum contention |
CN101174851B (en) * | 2006-11-03 | 2012-11-21 | 华为技术有限公司 | Method and device for detecting and identifying interference due to adjacent station |
KR100961745B1 (en) * | 2006-11-27 | 2010-06-07 | 삼성전자주식회사 | Apparatus and method for communicating channel information in relay wireless communication system |
US8687563B2 (en) * | 2007-01-09 | 2014-04-01 | Stmicroelectronics, Inc. | Simultaneous sensing and data transmission |
KR101316621B1 (en) * | 2007-01-11 | 2013-10-15 | 인하대학교 산학협력단 | Method and apparatus for communicating of distributed network system in a cognitive radio technique |
EP2127436A2 (en) * | 2007-01-24 | 2009-12-02 | Koninklijke Philips Electronics N.V. | Gathering and reporting data concerning communication channel conditions for a wireless device in a wireless network |
US8780852B2 (en) | 2007-05-11 | 2014-07-15 | Stmicroelectronics, Inc. | Multi-channel inter base-station communication |
US8199707B2 (en) | 2007-05-11 | 2012-06-12 | Stmicroelectronics, Inc. | Inter-cell discovery and communication using time division multiple access coexistence beaconing protocol |
US8411622B2 (en) * | 2007-05-11 | 2013-04-02 | Stmicroelectronics, Inc. | Multi-channel inter base-station communication |
US8081972B2 (en) * | 2007-05-25 | 2011-12-20 | Huawei Technologies Co., Ltd. | Method and system for sensing discontiguous channels in a wireless network |
EP2398272B1 (en) * | 2007-08-16 | 2013-03-20 | Panasonic Corporation | Signalling and mapping of measurement reports |
CN101388678B (en) * | 2007-09-10 | 2013-02-06 | 北京三星通信技术研究有限公司 | Initialization method protecting apparatus in radio microphone beacon system and protecting device |
US8014345B2 (en) * | 2007-10-31 | 2011-09-06 | Motorola Solutions, Inc. | Incumbent spectrum hold device |
US8320308B2 (en) * | 2007-11-07 | 2012-11-27 | Stmicroelectronics, Inc. | Parallel data services and spectrum sensing with cognitive channel switching in a wireless area network |
US8442445B2 (en) * | 2007-11-09 | 2013-05-14 | Bae Systems Information And Electronic Systems Integration Inc. | Protocol reference model, security and inter-operability in a cognitive communications system |
US8780882B2 (en) * | 2008-01-16 | 2014-07-15 | Stmicroelectronics, Inc. | On-demand spectrum contention for inter-cell spectrum sharing in cognitive radio networks |
US8824432B2 (en) * | 2008-01-16 | 2014-09-02 | Stmicroelectronics, Inc. | Beaconing period framing for efficient multi-channel inter-cell communications in cognitive radio networks |
WO2009101460A1 (en) * | 2008-02-11 | 2009-08-20 | Nokia Corporation | Method and apparatus for providing carrier indication and carrier sensing in a wireless network |
KR101559320B1 (en) * | 2008-02-18 | 2015-10-13 | 삼성전자주식회사 | Mobile system and base station system for effectively using licensed spectrum and shared spectrum |
EP2111071A1 (en) | 2008-04-17 | 2009-10-21 | Nokia Siemens Networks Oy | Methods, apparatuses, system, and related computer program product for reference signaling |
US8958371B2 (en) | 2008-09-12 | 2015-02-17 | Qualcomm Incorporated | Interference management for different wireless communication technologies |
EP2356763A1 (en) * | 2008-12-08 | 2011-08-17 | BAE Systems Information and Electronic Systems Integration Inc. | Method for collaborative discrimation between authentic and spurious signals in a wireless cognitive network |
US8107887B2 (en) * | 2009-02-27 | 2012-01-31 | Motorola Solutions, Inc. | Narrowband system and method for defining narrowband wideband channels in unused wideband channels |
EP2709304B1 (en) * | 2009-03-19 | 2015-11-18 | NEC Corporation | Improved channel quality indicator method |
US8843073B2 (en) * | 2009-06-26 | 2014-09-23 | Intel Corporation | Radio resource measurement techniques in directional wireless networks |
KR101404321B1 (en) * | 2009-09-24 | 2014-06-05 | 한국전자통신연구원 | Method and apparatus for sharing frequency based on classification of frequency set in incumbent system existing environment |
WO2011043372A1 (en) * | 2009-10-07 | 2011-04-14 | 住友電気工業株式会社 | Base station device, signal processing device for base station device, phy processing device, and mac processing device |
CN102656916B (en) * | 2010-04-11 | 2015-01-21 | Lg电子株式会社 | Apparatus and method of performing measurement logging in wireless communication system |
US8644290B2 (en) | 2010-04-12 | 2014-02-04 | National Taiwan University | Coordination-free rendezvous method for a communication network |
US9219571B2 (en) * | 2010-04-13 | 2015-12-22 | Qualcomm Incorporated | Aperiodic CQI reporting in a wireless communication network |
US8509833B2 (en) * | 2010-06-24 | 2013-08-13 | Qualcomm Incorporated | Method and apparatus for using and/or implementing control channels in white space |
JP5649166B2 (en) * | 2010-07-30 | 2015-01-07 | 独立行政法人情報通信研究機構 | Radio wave sensor and data transmission method |
WO2012057569A2 (en) * | 2010-10-31 | 2012-05-03 | 엘지전자 주식회사 | Method for acquiring resources in a coexistence system, and apparatus using same |
US8700085B2 (en) * | 2010-11-30 | 2014-04-15 | Intel Corporation | Dynamic interference mitigation for cellular networks |
EP2676465B1 (en) * | 2011-02-14 | 2017-05-10 | Nokia Solutions and Networks Oy | Secondary spectrum use |
GB201114079D0 (en) * | 2011-06-13 | 2011-09-28 | Neul Ltd | Mobile base station |
GB2493939A (en) | 2011-08-23 | 2013-02-27 | Nec Corp | Cognitive wireless communication network |
CN103313258A (en) * | 2012-03-07 | 2013-09-18 | 新加坡科技研究局 | Method, communication device and communication terminal for coordinating network operation |
CN103581962B (en) * | 2012-07-30 | 2016-08-10 | ***通信集团公司 | A kind of method, apparatus and system that down control channel is detected |
US20140044150A1 (en) * | 2012-08-13 | 2014-02-13 | Redline Communications, Inc. | System and method for interference triggered frequency hopping |
US9244694B2 (en) * | 2012-12-27 | 2016-01-26 | Intel Corporation | Executing a command within a transport mechanism based on a get and set architecture |
CN103200578B (en) * | 2013-04-15 | 2015-09-09 | 成都希盟泰克科技发展有限公司 | A kind of variable bandwidth channel distribution method based on cognition wireless local area network (LAN) |
KR101811166B1 (en) * | 2013-09-20 | 2017-12-20 | 인텔 코포레이션 | Ap location query |
US9474073B2 (en) * | 2013-10-31 | 2016-10-18 | Qualcomm Incorporated | Methods and apparatus for multiple user uplink bandwidth allocation |
CN103744051B (en) * | 2013-12-11 | 2016-03-23 | 南京邮电大学 | Base station identification approach in a kind of SFN positioning system |
WO2015096062A1 (en) * | 2013-12-25 | 2015-07-02 | 华为技术有限公司 | Spectrum sharing method and apparatus |
WO2015109516A1 (en) | 2014-01-24 | 2015-07-30 | 华为技术有限公司 | Measurement method, configuration method, related device and system |
CN105376751B (en) * | 2014-09-02 | 2019-06-11 | 中兴通讯股份有限公司 | A kind of detection, analysis, alarm method and device |
US9451612B2 (en) * | 2014-12-12 | 2016-09-20 | Huawei Technologies Co., Ltd. | Method and system for joint coordination and coexistence in unlicensed spectrum |
US10028162B2 (en) | 2015-08-12 | 2018-07-17 | Industrial Technology Research Institute | Method of controlling heterogeneous network and related apparatuses using the same |
DE102015121724A1 (en) * | 2015-12-14 | 2017-06-14 | Symeo Gmbh | System and method with at least three signals receiving stations |
CN106102164B (en) * | 2016-06-12 | 2018-08-17 | 北京三快在线科技有限公司 | A kind of method and apparatus of determining access point position |
CN108834162B (en) * | 2018-05-22 | 2021-09-24 | 京信网络***股份有限公司 | Beacon monitoring method, device, computer equipment and storage medium |
US11044753B2 (en) | 2019-02-12 | 2021-06-22 | Qts Holdings, Llc | Method for collision avoidance in transfer of network packets |
US10985799B1 (en) | 2020-01-15 | 2021-04-20 | Shure Acquisition Holdings, Inc. | Bi-directional multi-band frequency manager for a wireless microphone system |
US11930381B2 (en) * | 2020-06-26 | 2024-03-12 | Apple Inc. | Backup link for low latency communication |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6433740B1 (en) * | 1994-03-25 | 2002-08-13 | Qualcomm Incorporated | Determination method for use with analog cellular system |
US20020126780A1 (en) * | 2000-12-06 | 2002-09-12 | Matsushita Electric Industrial Co., Ltd. | OFDM signal transmissions system, porable terminal, and E-commerce system |
US20030069043A1 (en) * | 2001-10-10 | 2003-04-10 | Pallav Chhaochharia | Methods and devices for wirelessly transmitting data in dependence on location |
US20030156063A1 (en) * | 2001-08-17 | 2003-08-21 | Spilker James J. | Position location using integrated services digital broadcasting - terrestrial (ISDB-T) broadcast television signals |
US20040002344A1 (en) * | 2002-04-25 | 2004-01-01 | Mark Moeglein | Method and apparatus for location determination in a wireless assisted hybrid positioning system |
US6781974B1 (en) * | 1998-06-09 | 2004-08-24 | Nec Corporation | Method of assigning frequency using propagation loss |
US20040203715A1 (en) * | 2002-10-16 | 2004-10-14 | Camp William O. | Mobile terminal implementing a ranging signal receiver and method |
US20040248568A1 (en) * | 2003-02-18 | 2004-12-09 | Nortel Networks Limited. | Method of controlling a mode of reporting of measurements on a radio interface and radio network controller for the implementation of the method |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19901755C2 (en) * | 1999-01-18 | 2003-06-18 | Siemens Ag | Frequency band allocation to radio communication systems |
US6925068B1 (en) * | 1999-05-21 | 2005-08-02 | Wi-Lan, Inc. | Method and apparatus for allocating bandwidth in a wireless communication system |
DE50108493D1 (en) * | 2001-11-16 | 2006-01-26 | Swisscom Fixnet Ag Bern | METHOD AND SYSTEM FOR CLASSIFYING NETWORK CONNECTIONS |
US7352728B2 (en) * | 2002-03-07 | 2008-04-01 | Koninklijke Philips Electronics N.V. | Fast channel switching scheme for IEEE 802.11 WLANs |
CN1192503C (en) * | 2002-04-15 | 2005-03-09 | 华为技术有限公司 | Method for switching-on and synchronization of mobile terminal of radio local network system |
US7764617B2 (en) * | 2002-04-29 | 2010-07-27 | Harris Corporation | Mobile ad-hoc network and methods for performing functions therein based upon weighted quality of service metrics |
US6891496B2 (en) * | 2002-05-03 | 2005-05-10 | Atheros Communications, Inc. | Method and apparatus for physical layer radar pulse detection and estimation |
US7039417B2 (en) * | 2003-09-25 | 2006-05-02 | Lenovo Pte Ltd | Apparatus, system, and method for mitigating access point data rate degradation |
US6870815B2 (en) * | 2003-01-30 | 2005-03-22 | Atheros Communications, Inc. | Methods for implementing a dynamic frequency selection (DFS) and a temporary channel selection feature for WLAN devices |
JP4520705B2 (en) * | 2003-04-11 | 2010-08-11 | パナソニック株式会社 | Communication system and communication method |
US7640373B2 (en) * | 2003-04-25 | 2009-12-29 | Motorola, Inc. | Method and apparatus for channel quality feedback within a communication system |
KR100606129B1 (en) * | 2003-04-30 | 2006-07-28 | 삼성전자주식회사 | Method for measuring and reporting channel quality in broadband wireless access communication system |
JP4668170B2 (en) * | 2003-05-09 | 2011-04-13 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | System and method for specifying measurement request start time |
MXPA05012243A (en) * | 2003-05-14 | 2006-02-08 | Interdigital Tech Corp | Network management using periodic measurements of indicators. |
JP2005020626A (en) * | 2003-06-27 | 2005-01-20 | Nec Corp | Base station, wireless network system, wireless communication method and control program of base station |
US6958982B2 (en) * | 2003-07-16 | 2005-10-25 | Interdigital Technology Corporation | Method and apparatus for storing mobile station physical measurements and MAC performance statistics in a management information base of an access point |
US7286515B2 (en) * | 2003-07-28 | 2007-10-23 | Cisco Technology, Inc. | Method, apparatus, and software product for detecting rogue access points in a wireless network |
KR100976475B1 (en) * | 2003-08-19 | 2010-08-18 | 엘지전자 주식회사 | Method of securing quality of communication service |
US8472473B2 (en) * | 2003-10-15 | 2013-06-25 | Qualcomm Incorporated | Wireless LAN protocol stack |
JP2008520966A (en) * | 2004-11-15 | 2008-06-19 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Detection of microwave operation by scanning media noise pattern |
US7370362B2 (en) * | 2005-03-03 | 2008-05-06 | Cisco Technology, Inc. | Method and apparatus for locating rogue access point switch ports in a wireless network |
ATE468681T1 (en) * | 2005-03-14 | 2010-06-15 | Koninkl Philips Electronics Nv | METHOD AND SYSTEM FOR ANNOUNCEMENT OF ACCESS POINT CANDIDATES IN A WIRELESS NETWORK |
TW200721861A (en) * | 2005-09-09 | 2007-06-01 | Nokia Corp | Use of measurement pilot for radio measurement in a wireless network |
US8081972B2 (en) * | 2007-05-25 | 2011-12-20 | Huawei Technologies Co., Ltd. | Method and system for sensing discontiguous channels in a wireless network |
-
2005
- 2005-09-16 US US12/066,882 patent/US20080219201A1/en not_active Abandoned
-
2006
- 2006-09-14 AT AT06796030T patent/ATE453298T1/en not_active IP Right Cessation
- 2006-09-14 EP EP06796030A patent/EP1929820B1/en active Active
- 2006-09-14 DE DE602006011346T patent/DE602006011346D1/en active Active
- 2006-09-14 CN CN2006800424303A patent/CN101310548B/en not_active Expired - Fee Related
- 2006-09-14 KR KR1020087006049A patent/KR101243683B1/en active IP Right Grant
- 2006-09-14 CN CN200680042420XA patent/CN101310547B/en active Active
- 2006-09-14 WO PCT/IB2006/053286 patent/WO2007031956A2/en active Application Filing
- 2006-09-14 CN CN2006800425490A patent/CN101310556B/en active Active
- 2006-09-14 CN CN2006800342106A patent/CN101268711B/en active Active
- 2006-09-14 US US12/066,851 patent/US7756058B2/en active Active
- 2006-09-14 CN CN2006800415681A patent/CN101305627B/en active Active
- 2006-09-14 JP JP2008530713A patent/JP5160427B2/en active Active
- 2006-09-14 CN CN2006800423936A patent/CN101310477B/en active Active
- 2006-09-14 CN CN2006800418533A patent/CN101305635B/en active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6433740B1 (en) * | 1994-03-25 | 2002-08-13 | Qualcomm Incorporated | Determination method for use with analog cellular system |
US6781974B1 (en) * | 1998-06-09 | 2004-08-24 | Nec Corporation | Method of assigning frequency using propagation loss |
US20020126780A1 (en) * | 2000-12-06 | 2002-09-12 | Matsushita Electric Industrial Co., Ltd. | OFDM signal transmissions system, porable terminal, and E-commerce system |
US20030156063A1 (en) * | 2001-08-17 | 2003-08-21 | Spilker James J. | Position location using integrated services digital broadcasting - terrestrial (ISDB-T) broadcast television signals |
US20030069043A1 (en) * | 2001-10-10 | 2003-04-10 | Pallav Chhaochharia | Methods and devices for wirelessly transmitting data in dependence on location |
US20040002344A1 (en) * | 2002-04-25 | 2004-01-01 | Mark Moeglein | Method and apparatus for location determination in a wireless assisted hybrid positioning system |
US20040203715A1 (en) * | 2002-10-16 | 2004-10-14 | Camp William O. | Mobile terminal implementing a ranging signal receiver and method |
US20040248568A1 (en) * | 2003-02-18 | 2004-12-09 | Nortel Networks Limited. | Method of controlling a mode of reporting of measurements on a radio interface and radio network controller for the implementation of the method |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090219944A1 (en) * | 2005-11-07 | 2009-09-03 | Ying Chang Liang | Methods and devices for allocating frequency ranges |
US20090252096A1 (en) * | 2005-11-07 | 2009-10-08 | Thmpson Licensing | Apparatus and Method for Dynamic Frequency Selection in Wireless Networks |
US8204071B2 (en) * | 2005-11-07 | 2012-06-19 | Agency For Science, Technology And Research | Methods and devices for allocating frequency ranges |
US20090028077A1 (en) * | 2007-07-23 | 2009-01-29 | Jennic Ltd. | Method of determining the location of a node in a distributed wireless sensor and actuator network |
US8515454B2 (en) * | 2007-07-23 | 2013-08-20 | Nxp B.V. | Method of determining the location of a node in a distributed wireless sensor and actuator network |
US20090298522A1 (en) * | 2008-05-30 | 2009-12-03 | Motorola, Inc. | Coexistence and incumbent protection in a cognitive radio network |
US20090296000A1 (en) * | 2008-05-30 | 2009-12-03 | Echostar Technologies L.L.C. | Systems, methods and apparatus for exchanging data between television receivers over a wireless communication link |
US8060104B2 (en) * | 2008-05-30 | 2011-11-15 | Motorola Solutions, Inc. | Coexistence and incumbent protection in a cognitive radio network |
US8566882B2 (en) * | 2008-05-30 | 2013-10-22 | EchoStar Technologies, L.L.C. | Systems, methods and apparatus for exchanging data between television receivers over a wireless communication link |
US9363724B2 (en) | 2009-04-06 | 2016-06-07 | Interdigital Patent Holdings, Inc. | Television band (TVBD) channel quieting across diverse radio access technologies |
US20110080878A1 (en) * | 2009-07-03 | 2011-04-07 | Robert Novak | Method for control signaling for group of users using ms assignment index |
US20130016671A1 (en) * | 2011-01-17 | 2013-01-17 | Hao-Chung Cheng | Method of Handling Coordinated Scheduling for Base Stations and Mobile Devices and Related Communication Device |
US11363615B2 (en) * | 2014-05-22 | 2022-06-14 | Kyocera Corporation | Assignment of communication resources in an unlicensed frequency band to equipment operating in a licensed frequency band |
US11683796B2 (en) * | 2014-05-22 | 2023-06-20 | Kyocera Corporation | Assignment of communication resources in an unlicensed frequency band to equipment operating in a licensed frequency band |
US9661598B2 (en) * | 2015-09-30 | 2017-05-23 | Mitsubishi Electric Research Laboratories, Inc. | System and method for reducing interference between multiple terminals |
US10678353B2 (en) | 2015-12-28 | 2020-06-09 | Fuji Xerox Co., Ltd. | Electronic apparatus for communication between electronic pen and external device |
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CN101305635B (en) | 2011-12-14 |
CN101310477A (en) | 2008-11-19 |
CN101310547A (en) | 2008-11-19 |
CN101305627B (en) | 2012-07-11 |
CN101310548A (en) | 2008-11-19 |
WO2007031956A2 (en) | 2007-03-22 |
US7756058B2 (en) | 2010-07-13 |
CN101310547B (en) | 2012-11-14 |
US20080259811A1 (en) | 2008-10-23 |
DE602006011346D1 (en) | 2010-02-04 |
JP5160427B2 (en) | 2013-03-13 |
CN101268711A (en) | 2008-09-17 |
CN101310548B (en) | 2013-01-02 |
CN101310556A (en) | 2008-11-19 |
EP1929820A2 (en) | 2008-06-11 |
CN101305635A (en) | 2008-11-12 |
WO2007031956A3 (en) | 2007-10-18 |
JP2009509380A (en) | 2009-03-05 |
CN101268711B (en) | 2012-01-04 |
ATE453298T1 (en) | 2010-01-15 |
EP1929820B1 (en) | 2009-12-23 |
CN101310556B (en) | 2012-06-27 |
CN101310477B (en) | 2012-12-26 |
CN101305627A (en) | 2008-11-12 |
KR101243683B1 (en) | 2013-03-14 |
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