Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/90—Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/02—Services making use of location information
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/02—Services making use of location information
  • H04W4/029—Location-based management or tracking services
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/50—Connection management for emergency connections
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/08—Access point devices
  • H04W88/085—Access point devices with remote components

Definitions

• This disclosure relates to determining the location of a mobile communication device.
• a cellular communication system comprises a number of base stations, each of which uses one or more antenna elements to serve one or more cells (geographic regions).
• the base station functions to communicate with mobile communication devices (MCDs) (e.g., smartphones, tables, phablets, etc.) to provide the MCD with access to a network (e.g., the Internet or other network).
• MCDs mobile communication devices
• a base station typically includes at least an antenna element, a radio unit (RU) and a digital unit (DU).
• An RU typically includes a receiver and a transmitter in order to transmit data to and receive data from an MCD.
• the signal transmitted by a base station may be received by an MCD with poor quality when the MCD is in certain locations.
• the MCD may not receive a strong signal from the antenna.
• the MCD may have transmit the signal using more power than the MCD would have had to use had the MCD been located outdoors. Such a situation reduces the MCD's battery life.
• a solution to this problem is to install small transceiver units (a.k.a., "radio heads”) indoors and connect each of the radio heads to an RU of a base station using a cable (e.g., local area network (LAN) cable, such as an Ethernet cable).
• a cable e.g., local area network (LAN) cable, such as an Ethernet cable.
• LAN local area network
• a radio head connected via a cable to an RU may be placed on each floor of the building.
• Such a radio head receives via the cable a signal transmitted from the RU and then retransmits the signal wirelessly so that the signal will be received with good quality by an MCD located in the vicinity of the radio head.
• radio heads include one or more antenna elements for broadcasting and receiving wireless signals, and radio heads may also include amplifiers so that a received signal (e.g., a signal from an RU or a wireless signal from an MCD) can be amplified before it is retransmitted.
• a received signal e.g., a signal from an RU or a wireless signal from an MCD
• RDS Radio Dot System
• radio heads are each connected to an RU via an Ethernet cable.
• the radio heads receive power as well as the communication signals via the cable.
• each such radio head transmits with a maximum power of 100 mW.
• Power amplifiers are located in the radio head.
• Emergency positioning needs e.g., E-911
• LCS location services
• emergency position requirements may require horizontal inaccuracy to be below 50 meters.
• vertical inaccuracy requirement has recently been tightened to 3 meters in North America in order to better distinguish between floors in buildings.
• This disclosure relates to systems and methods for determining the location of an
• a method is performed by a positioning system for determining the location of the MCD.
• the positioning system includes one or more of: a positioning node and a base station.
• the method includes the step of determining a cell in which the MCD is located (e.g., receiving a message including a cell identifier (cell ID) identifying the cell in which the MCD is located).
• the determined cell is served by a serving base station connected to a set of radio heads.
• Each one of the radio heads included in the set of radio heads is connected to the base station via a cable.
• the method further includes determining a cable length value (e.g., a cable loss value) representative of the length of the cable connecting the base station to a radio head serving the MCD.
• the method further includes using the determined cable length value to obtain location information identifying a location of the MCD.
• the location information may be associated with a fingerprint and comprise one or more of: i) a set of polygon coordinate vectors and ii) a set of coordinates derived from the set of polygon coordinate vectors.
• the step of determining the cable length value comprises: a positioning node of the positioning system receiving a message transmitted by the serving base station, the message comprising a measurement result information element, IE; and the positioning node using information included in the measurement result information element to calculate the cable length value.
• the positioning node may be an Evolved Serving Mobile Location Center, E-SMLC.
• the message may be an E-CK) MEASUREMENT INITIATION RESPONSE or an E-CK) MEASUREMENT REPORT.
• the information included in the measurement result information element may include one or more of: an amplifier gain value, G amp, a downlink path loss value, L dl, a power value indicative of a radio head transmit power, Prh, a noise factor of a radio unit of the serving base station, NF ru, an inter-cell interference value, I du, an uplink transmit power value P ul mcd indicating the transmit power of an uplink signal transmitted by the MCD, a power value representative of the power of the uplink signal transmitted by the MCD as measured by the serving base station, P ul mcd du, and a signal to noise and interference ratio of the MCD as measured by a DU of the base station serving the MCD, SINR_mcd_du.
• the step of determining the cable length value further comprises: the positioning node receiving a second message transmitted by the MCD, the second message comprising a received power value indicating a received power of a downlink signal transmitted by the serving radio head as measured by the MCD, P dl mcd, and the positioning node using the information included in the measurement result information element and the P dl mcd to calculate the cable length value.
• the serving base station is a component of the positioning system.
• the step of using the determined cable length value to obtain location information for the MCD may include: the serving base station generating a calculated cable length value; the serving base station determining the cable length value by selecting at least one predetermined cable length value using the calculated cable length value; and the serving base station transmitting to a positioning node of the positioning system a message comprising a radio head identifier identifying one of the radio heads, wherein the radio head identifier comprises at least one of: the selected cable length value and an identifier to which the selected cable length value is mapped.
• the positioning node uses the radio head identifier to obtain the location information.
• the step of using the determined cable length value to obtain the location information for the MCD may include the serving base station generating a calculated cable length value and transmitting to a positioning node of the positioning system a message comprising the calculated cable length value.
• the positioning node receives the message, determines the cable length value by selecting at least one predetermined cable length value using the received calculated cable length value, and uses the determined cable length value to obtain the location information for the MCD.
• the method further comprises the serving base station 1) receiving an RRC message transmitted by the MCD, the RRC message comprising a received power value indicating a received power of a downlink signal transmitted by the serving radio head as measured by the MCD, P dl mcd and 2) using P dl mcd to calculate the calculated cable length value.
• the obtained location information comprises one or more of i) a set of polygon coordinate vectors and ii) a set of coordinates derived from the set of polygon coordinate vectors.
• using the determined cable length value to obtain the location information for the MCD comprises forming a fingerprint using the determined cable length value and using the formed fingerprint to obtain the location information for the MCD.
• the location information may include the set of polygon coordinate vectors, and the set of polygon coordinate vectors define a polygon and comprise at least three polygon coordinate vectors, each polygon coordinate vector comprising at least a first coordinate and a second coordinate.
• the method may further include obtaining one or more measured radio property values, wherein the step of forming the fingerprint using the determined cable length value comprises forming the fingerprint using both the determined cable length value and the one or more measured radio property values.
• using the fingerprint to obtain the location information comprises sending to a database server a query for location information, where the query includes the fingerprint.
• the database server uses the fingerprint included in the query to lookup the location information in a database.
• the invention in another aspect, relates to a positioning system for determining the location of an MCD.
• the positioning system is adapted to determine a cell in which the MCD is located.
• the positioning system is further adapted to, such that, if the determined cell is being served by a serving base station connected to a set of radio heads via a set of corresponding cables, the positioning system determines a cable length value representative of the length of a cable connecting the base station to a radio head serving the MCD and uses the determined cable length value to obtain location information for the MCD.
• FIG. 1 is a block diagram of a positioning system, according to some embodiments.
• FIG. 2 is a flow chart of a location process, according to some embodiments.
• FIG. 3 is a flow chart of a process for determining a cable length value, according to some embodiments.
• FIG. 4 is a flow chart of a process for determining a cable length value, according to some embodiments.
• FIG. 5 is a flow chart of a process for determining the uplink path loss between an
• MCD and the serving radio head according to some embodiments.
• FIG. 6 is a flow chart of a process for using a determined cable length value to obtain location information for an MCD, according to some embodiments.
• FIG. 7 is a flow chart of a location process, according to some embodiments.
• FIG. 8 is a flow chart of a location process, according to some embodiments.
• FIG. 9 is a flow chart of a location process, according to some embodiments.
• FIG. 10 is a flow chart for creating a database that associates fingerprints with location information, according to some embodiments.
• FIG. 1 1 is a block diagram of a positioning node apparatus, according to some embodiments.
• FIG. 12 is a block diagram of a digital unit apparatus, according to some embodiments.
• MCD that is being served by a radio head by determining a value corresponding to the length of the cable connecting the serving radio head to a base station (e.g., by determining the cable gain/loss).
• a significant advantage of the disclosed systems and methods is that they may provide up to eight times reduced position inaccuracy as compared to cell ID positioning.
• the disclosed techniques can be used to improve the accuracy of Radio
• TPSs Trace processing servers
• FIG. 1 is a block diagram of a positioning system 100, according to some embodiments.
• the positioning system 100 includes a base station 104, which comprises a radio unit (RU) 103 and a digital unit (DU) 105.
• the RU 103 and the DU 105 may be housed in the same housing or they be housed in separate housings that may or may not be co-located.
• DU 105 may be connected to the RU 103 via a cable (e.g., optical, electrical).
• a set of one or more radio heads 107 is connected to base station 104 (more specifically, the radio heads are connected to RU 103 of base station 104).
• each radio head 107 is connected via a cable 108, such as a local area network (LAN) cable (e.g., an Ethernet cable or other LAN cable), to the RU 103.
• Radio heads 107 includes one or more antenna elements for wirelessly transmitting signal to an MCD 120 and for wirelessly receiving signal transmitted by MCD 120.
• radio heads 107 may further comprise a power amplifier.
• RU 103 may comprise an indoor radio unit (IRU), and radio heads 107 may deliver mobile broadband access to the MCD 120 in a broad range of indoor locations.
• IRU indoor radio unit
• Base station 104 may be connected to a core network 130 that includes a positioning node 140 for processing position requests as well as other core network nodes (e.g., a Mobility Management Entity (MME), a Serving Gateway (SGW), and Packet Data Network Gateway (PGW)).
• MME Mobility Management Entity
• SGW Serving Gateway
• PGW Packet Data Network Gateway
• the embodiments disclosed herein are not limited to any specific type of core network.
• the positioning node 140 may comprise or consist of an Evolved Serving Mobile Location Center (E-SMLC) and the base station 104 may comprise or consist of an enhanced Node B (eNB).
• E-SMLC Evolved Serving Mobile Location Center
• eNB enhanced Node B
• the positioning node 140 may comprise or consist of a stand-alone Serving Mobile Location Center (SAS) and the base station 104 may comprise or consist of a Node B.
• SAS Serving Mobile Location Center
• the positioning node 140 may also be located in a radio network controller (RNC).
• RNC radio network controller
• an LCS client 160 may transmit a positioning request to positioning node 140.
• LCS Client 160 may be a computer server connected to a network (e.g., the Internet), and thus is external to the core network 130.
• core network 130 is an LTE network
• GMLC Location Center in network 130 may receive from the external LCS client 160 a position request for a particular location services target, e.g., MCD 120.
• the GMLC may then transmit the position request to an MME in core network 130.
• the MME may in turn forward the request to the positioning node 140 (E-SMLC in this example).
• the positioning node 140 may then process the location services request to perform a positioning of the target MCD 120.
• the positioning node 140 may perform some or all of the processing for performing the calculations described in connection with FIGs. 2-6.
• the base station 104 may perform some or all of the processing for performing the calculations described below in connection with FIGs. 2-6.
• the positioning node may then return the result of the position request back to the MME, which in turn will forward the position result back to requesting LCS client 160 (e.g., through the GMLC and network 110).
• positioning node 140 is configured to determine the location of the MCD 120 by determining a value representative of the length of the cable connecting the radio head 107 that is serving MCD 120 to base station 104.
• data from the DU 105 is sent to the RU 103 where it is transmitted in analogue form to the radio heads 107.
• the signal received on each of the radio heads 107 from the MCD 120 is amplified and then sent to the base station 104.
• the gain of the amplifier can be set individually for each radio head 107. In some embodiments, there may be significant losses (e.g., up to 30 dB) associated with each cable (up to 200m) connecting the one or more radio heads 107 to the base station 104. In some embodiments, such loss values may be configured in a database in base station 104.
• an estimate of the cable loss (L cable) of the cable 108 connecting base station 104 with the radio head 107 serving the MCD 120 is calculated and then used to determine the location of MCD 120.
• the estimated cable loss can be used to determine a position of the MCD because, in many networks, each cable 108 connecting one of the radio heads 107 to base station 104 has a unique cable loss (cable loss is directly proportional to cable length and in many networks each radio head connected to a particular RU of base station 104 is connected by cable having a length that is different than the lengths of the other cables used to connect the other radio heads to the RU).
• the estimated cable loss value is accurate enough, it can be mapped to a specific location because the actual cable lengths (or actual cable losses) may be measured at installation of the radio heads.
• the location of the MCD can be determined more accurately as the cell coverage area may be split up into smaller areas corresponding to each radio head.
• each radio head is associated with one floor of a building, it may be further possible to resolve location information to a floor of that building.
• a fingerprint can be formed using, among other things, a cable length value (e.g., the cable loss value) determined as described herein.
• This fingerprint can be associated with location information (e.g., a set of polygon coordinate vectors that define an adaptive enhanced cell ID (AECID) polygon and/or a set of coordinates derived from the set of polygon coordinate vectors (e.g., the derived set of coordinates corresponding to the center of gravity of the polygon)).
• AECID adaptive enhanced cell ID
• a "fingerprint” is a set of one or more measured/determined values or a set of one or more values derived from the measured values.
• a fingerprint is formed from a determined cable length value and a set of one or more measured radio property values, which may include one or more of: a pathloss value, a cell identifier (ID), a received signal strength (RSS) value, a timing advance (TA) value, and angle of arrival (AoA) values.
• a pathloss value a cell identifier
• RSS received signal strength
• TA timing advance
• AoA angle of arrival
• a positioning system can obtain fingerprint information (e.g., determined cable length value, RSS, pathloss, TA, AoA, etc.) from, for example, an MCD and/or a base station serving the MCD, and use the obtained fingerprint information to generate a fingerprint and then use the fingerprint to query a location information database for location information (e.g. coordinate vector(s)) associated with the generated fingerprint.
• fingerprint information e.g., determined cable length value, RSS, pathloss, TA, AoA, etc.
• FIG. 2 is a flow chart of a positioning process 200, according to some embodiments, performed by a positioning system for determining the location of MCD 120.
• the positioning system comprises one or more of: MCD 102, positioning node 140, and base station 104.
• step 202 includes determining a cell in which MCD 120 is located, the determined cell being served by a serving base station (base station 104, in this example).
• base station 104 serving base station
• cellular systems may be divided into cells (which may overlap), and each cell may be served by one specific base station.
• step 202 comprises or consists of the positioning system obtaining a cell identifier (Cell ID) identifying the cell in which the MCD is located (e.g., receiving a message comprising the Cell ID).
• Cell ID cell identifier
• the positioning system determines whether the determined cell is being served by a plurality of radio heads (step 203). If this is the case, then the process proceeds to step 204. For example, in step 203 the positioning system may use the Cell ID to obtain a database record from a database, which database record includes information identifying whether or not the determined cell is being served by a plurality of radio heads.
• Step 204 includes determining a cable length value (C length) representative of the length of the cable connecting the serving base station to the radio head serving the MCD.
• determining the cable length value consists of determining L cable (defined above). That is, L cable is the determined cable length value.
• the positioning node 140 may instruct the base station 104 to perform step 204.
• the determined cable length value is used to obtain location information for the MCD.
• the determined cable length value can be a fingerprint (or can be used to form a fingerprint as described below with reference to FIG. 6) that is used in an AECID fingerprint positioning method.
• the location information obtained in step 206 may define an area in which the MCD is likely to be found.
• the location information obtained in step 206 is a set of polygon coordinate vectors that together define a polygon defining an area in which the MCD is likely to be found.
• the polygon defined by the polygon coordinate vectors may be an AECID polygon, such as a polygon formed by the method disclosed in U.S. Patent Pub. No. 2013/0210458 or by the method disclosed in reference
• each polygon coordinate vector has only two coordinates that define a point (e.g., a vertex of the polygon) on a two dimensional surface (a latitude and longitude). In other embodiments, each polygon coordinate vector has at least three coordinates that define a point in a three dimensional space (e.g., latitude, longitude, and altitude).
• the location information obtained in step 206 is a set of coordinates derived from a set of polygon coordinate vectors (e.g., the derived set of coordinates corresponding to the center of gravity of the polygon defined by the polygon coordinate vectors).
• obtaining the location information for the MCD comprises: obtaining a set of predetermined cable length values; determining which one of a set of predetermined cable length values is closest to the determined cable length value; and estimating the location of the MCD using the predetermined cable length value that was determined to be closest to the determined cable length value.
• predetermined cable length value that was determined to be closest to the determined cable length value comprises using the predetermined cable length value to retrieve location information from a database (e.g., from a table) (e.g., using an identifier to which the
• each of the predetermined cable length values is mapped to retrieve the location information).
• each of the predetermined cable length values may be stored in a table that maps the
• estimating the location of the MCD further comprises obtaining a path loss value representative of a path loss between the MCD and the serving radio head and using the path loss value to estimate the distance between the MCD and the serving radio head.
• This path loss feature enables the positioning system to further narrow the area in which the MCD is likely to be found.
• an Adaptive Enhanced Cell Identity (AECID) fingerprinting method known in the art could be augmented to take into account location information determined in step 206.
• the location of the MCD may be determined to be the union of the coverage areas of the radio heads corresponding to the subset of predetermined cable length values.
• each of the plurality of predetermined cable length values i.e., C_length_pre_i
• each of the plurality of predetermined cable length values is compared against at least one of the calculated cable length values in order to determine the subset of zero or more predetermined cable length values that are within a threshold distance of a calculated cable length value. As discussed above, this determined subset of predetermined cable length values is used to determine the position of the MCD.
• the set of predetermined cable length values may be obtained by retrieving the set of values from a database using the cell ID of the cell in which the MCD is located. That is, in some embodiments, the database links each cell ID included in a certain set of cell IDs with a set of cable length values. For example, suppose a given cell ID (e.g., cell-id-123) identifies a cell served by an RU of a base station that is connected to a set of radio heads. The database may link the given cell ID with a set of cable length values, where each one of the cable length values represents the length of the cable connecting one of the radio heads to the RU. The database may be hosted by DU 105, positioning node 140, or another entity.
• a given cell ID e.g., cell-id-123
• the database may link the given cell ID with a set of cable length values, where each one of the cable length values represents the length of the cable connecting one of the radio heads to the RU.
• the database may be hosted by DU
• a 90% confidence radius (or other pre-configured confidence limit) may be calculated for every radio head position by calculating the standard deviation of C_length_pre_i around determined C length.
• the confidence radius around the radio head will be given as function of Standard deviation of C_length_pre_i shown below in the equation below:
• RH Conf Radius f(Standard_deviation(C_length_pre_i)).
• the calculated confidence interval could then be forwarded to a location based service or TPS system in a similar manner as Cell ID, TA, and other methods.
• FIG. 3 is a flow chart of a process 300, according to some embodiments, performed by the positioning system for determining a cable length value (step 204).
• the positioning system includes one or more of: positioning node 140 and base station
• an uplink path loss value (L ul) representative of the uplink path loss between the MCD and the serving radio head is determined.
• L ul may be determined from a calculated downlink path loss (L dl) value.
• the positioning node 140 may first order the base station 104 to determine the downlink path loss (L dl). Determination of the L ul value from the L dl value is described in further detail below in connection with FIG. 5.
• a power measurement report comprising an uplink transmit power value (P ul mcd) indicating the transmit power of an uplink signal transmitted by the MCD is received.
• the MCD 120 may report its uplink transmit power P ul mcd.
• measurement orders may be transmitted to the MCD 120 from the serving base station 104 for the MCD to report the P ul mcd value.
• TPS may utilize 3G/4G Radio Enhanced Statistics (RES) features which turn on measurements on all MCDs to report P ul mcd, the uplink transmit power, in measurement reports.
• RES Radio Enhanced Statistics
• the base station 104 may receive the P ul mcd value from the base station and perform further processing using that value. In other embodiments, the base station 104 may forward the P ul mcd value to the positioning node 140 for further processing.
• step 306 an amplifier gain value is obtained.
• the amplifier gain value is obtained.
• G amp may be set individually for each radio head 107a to 107n or each radio head may use the same amplifier gain value. In the latter case, only a single cable length value needs to be calculated, otherwise, in the former case the set of cable length values (C length i) is calculated, as described above.
• the positioning node 140 and/or base station 104 may obtain G amp from preconfigured information stored in a database.
• step 308 the power value representative of the power of the uplink signal transmitted by the MCD as measured by the serving base station (P ul mcd du) is obtained.
• the P ul mcd du value can be determined from power headroom reports and the configured maximum value of the MCD 120 power.
• the received MCD power (P ul mcd du) is measured directly in the DU 105 of base station 104, e.g., after de-spreading in a WCDMA network.
• the base station 104 sends the P ul mcd du value to the positioning node 140, for further processing.
• step 310 P ul mcd - L ul + G amp- P ul mcd du is calculated.
• the positioning node 140 performs the calculation in step 310.
• the base station 104 performs the calculation in step 310.
• the cable loss value for the radio head (L cable) connected to the MCD 120 is calculated according to the equation below:
• the cable loss value L cable is representative of the length of the cable connecting the serving base station 104 to the radio head 107 serving the MCD 120.
• FIG. 4 is a flow chart of a process 400 for determining a cable length value, according to other embodiments.
• the steps of cable length value determination process 400 may be performed by a positioning node 140.
• the steps of cable length value determination process 400 may be performed by both a positioning node 140 and a base station 104.
• process 400 includes steps 302- 306 (see FIG. 3).
• step 402 the following values are obtained: i) a signal to noise and interference ratio of the MCD as measured by a DU of the base station serving the MCD (SINR mcd du), ii) an inter-cell interference value (I_du), iii) a thermal noise power value (NO), and iv) a noise factor of a radio unit of the serving base station (NF ru).
• SINR mcd du signal to noise and interference ratio of the MCD as measured by a DU of the base station serving the MCD
• I_du inter-cell interference value
• NO thermal noise power value
• NF ru a noise factor of a radio unit of the serving base station
• the SINR mcd du value is measured by the DU 105 of the serving base station
• the base station 104 may obtain the SINR mcd du value and perform further processing using that value.
• the DU 105 of base station 104 may simply transmit the SINR mcd du value to the positioning node 140 for further processing.
• the NO + NF ru value may be estimated in the RU 103 of base station 104.
• pre-configured values instead of estimating values of NO + NF_ru, pre-configured values may be used. In other embodiments, different algorithms may be used to estimate the NO + NF_ru value.
• One algorithm for estimating the NO + NF ru value is the so denoted sliding window noise floor estimation. Since it may not be possible to obtain exact estimates of this value due to neighbor cell interference, the estimation algorithm applies an approximation using the soft minimum computed over a long window of time. Thus, this estimation relies on the fact that the noise floor may be constant over very long periods of time, disregarding the small temperature drift.
• the sliding window algorithm has a disadvantage of requiring a large amount of storage memory. The amount of storage memory may be particularly troublesome in cases where a large number of instances of the algorithm are needed, which may be the case when interference cancellation is introduced in the uplink.
• Another algorithm for estimating the NO + NF ru value is the so denoted recursive noise floor estimation.
• recursive noise floor estimation For example, to reduce the memory consumption of the sliding window algorithm described above, one such recursive algorithm is disclosed in T. Wigren, "Recursive noise floor estimation in WCDMA," IEEE Trans. Vehicular Tech., vol. 69, no. 5, pp. 2615-2620, 2010. The recursive algorithm may reduce the memory requirements of the sliding window algorithm described above by at least a factor of 100.
• the NO + NF ru value may be estimated by the base station 104 and be used for further processing. In some embodiments, the base station 104 may forward the NO + NF_ru value to the positioning node 140 for further processing.
• I du P mcd total - P ul mcd du - NO - NF ru
• step 404 the following value is calculated, which is representative of the cable loss value of the cable (L cable) connecting the serving base station 104 to the radio head 107 serving the MCD 120:
• L_cable P_ul_mcd - L_ul + G_amp - (SINR_mcd_du + I_du + NO + NF_ru)
• P_ul_mcd_du SINR_mcd_du + I_du + NO + NF_ru
• FIG. 5 is a flow chart of a process 500, according to some embodiments, for determining an uplink path loss value (L ul) representative of the uplink path loss between the MCD and the serving radio head.
• L ul uplink path loss value
• step 502 a power measurement report comprising a received power value
• TPS may utilize 3G/4G RES features which turn on measurements on all MCDs to report Pdl mcd, the downlink transmit power, in measurement reports. These measurements are called UeRxPower measurement and are reported periodically (e.g., as frequently as every 2 seconds).
• the MCD 120 may transmit the measured P dl mcd value in a measurement report as the UeRxPower to the base station 104.
• base station 104 may send the P dl mcd value to the positioning node 140 for determination of L ul, and in other embodiments, determination of L ul may be performed by the base station 104.
• a downlink path loss value (L_dl) is determined, wherein the determination comprises calculating (P dl mcd - Prh), wherein Prh is a value representative of the power at which the radio head transmitted the downlink signal.
• Prh is a value representative of the power at which the radio head transmitted the downlink signal.
• the configured downlink transmit power Prh may be known for each radio head 107.
• a downlink path loss value (L dl ) may be determined according to the equation below:
• the L dl i value may be determined according to the equation below:
• a dedicated measurement may be used for
• the uplink path loss value is calculated using the determined downlink path loss value.
• the uplink path loss value (L ul) may be determined from the downlink path loss (L dl) value determined in step 504.
• the positioning node 140 may then order the base station 104 to perform a measurement of the uplink path loss (L ul).
• the positioning node 140 may perform a measurement of the uplink path loss.
• FIG. 6 is a flow chart of a process 600 for performing step 206 (i.e., a process for using a determined cable length value to obtain location information for an MCD), according to some embodiments.
• Process 600 begins in step 602, where one or more measured radio property values is obtained.
• the radio property values obtained in step 602 may include one or more of: a pathloss value indicating a pathloss between MCD 120 and base station 104, a cell identifier (ID) identifying base station 104, a received signal strength (RSS) value indicating the strength of a signal received by MCD 120, a timing advance (TA) value, and angle of arrival (AoA) values.
• a pathloss value indicating a pathloss between MCD 120 and base station 104
• ID cell identifier
• RSS received signal strength
• TA timing advance
• AoA angle of arrival
• a fingerprint is formed using the determined cable length value (e.g. cable loss value, as described herein) and the obtained radio property value(s).
• Forming the fingerprint in some embodiments, consists of forming a data structure that stores the determined cable length value and the obtained radio property value(s). In other embodiments, forming the fingerprint consists of calculating a value or values based on the determined cable length value and the obtained radio property value(s). For example, a hash function can be used to generate the fingerprint from the determined cable length value and the obtained radio property value(s).
• step 606 the fingerprint formed in step 604 is used to retrieve the location information.
• positioning node 140 may form a query comprising the fingerprint and send the query to a database server (DS) 141 that uses the fingerprint to lookup in a location fingerprint database 142 location information that is associated with the fingerprint and then provide the retrieved location information to positioning node 140.
• DS database server
• the database server 141 and/or database 142 may be a component of positioning node 140.
• FIG. 7 is a flow chart of a location process 700, according to some embodiments, for locating MCD 120.
• Process 700 may be performed by positioning system 100 (e.g., it may be performed in whole or in part by the positioning node 140 and/or the base station 104).
• a request is received to locate MCD 120.
• the location request may be submitted by a LCS client 160 to the positioning node 140, potentially through one or more intermediaries as described above. In some embodiments, once the positioning node 140 receives the location request.
• step 704 a cell ID positioning is performed.
• the positioning node For example, the positioning node
• positioning node may receive from base station 104 an Long Term Evolution (LTE) Positioning Protocol A (LPPa) message comprising an E-CID Measurement Result Information Element (IE), which contains a Physical Cell Identifier (PCI) and a E-UTRAN Cell Global Identifier (ECGI).
• LTE Long Term Evolution
• LPPa Positioning Protocol A
• IE E-CID Measurement Result Information Element
• PCI Physical Cell Identifier
• ECGI E-UTRAN Cell Global Identifier
• step 705 based on the obtained cell ID, a determination is made as to whether the cell identified by the cell ID is served by a plurality of radio heads connected to a base station. If yes, the process continues to step 706, otherwise the process ends.
• the cable loss estimate L cable may be calculated by the positioning node 140 and/or the base station 104 as described above in connection with FIGs. 3-4.
• base station 104 may be configured to provide to positioning node 140 the L cable value.
• base stationl04 may provide to node 140 an LPPa message (e.g., an E-CK) Measurement Initiation Response or an E-CID Measurement Report) comprising an E-CID Measurement Result IE, which IE may also comprise the L cable value in addition to the cell identifiers.
• an LPPa message e.g., an E-CK
• Measurement Initiation Response or an E-CID Measurement Report comprising an E-CID Measurement Result IE, which IE may also comprise the L cable value in addition to the cell identifiers.
• step 708 a set of one or more radio property values are obtained (e.g., step 708 may be the same as step 602 of process 600).
• step 710 a fingerprint is formed using L cable and the values obtained in step
• step 708 (e.g., step 710 may be the same as step 604 of process 600).
• step 712 a query for location information is submitted to database server 141 , where the query includes the fingerprint.
• step 714 location information associated with the fingerprint is received from the database server 141.
• the location information may comprise a set of polygon coordinate vectors and/or a set of coordinate derived from the coordinate vectors.
• step 716 the location information (or location information derived therefrom) is transmitted to the entity that requested the positioning of MCD 120.
• FIG. 8 is a flow chart illustrating a process 800, according to some embodiments, for implementing step 706 in embodiments where positioning node 140 performs step 706.
• step 706 may begin with positioning node 140 transmitting a first request to the base station serving the cell identified in step 704 (step 802).
• the first request is an LPPa E-CK ) Measurement Initiation Request.
• the serving base station transmits a response and positioning node receives the response (step 804).
• the response is one of an LPPa E-CK ) Measurement Initiation Response message and an LPPa E-CID Measurement Report message, each of which includes an LPPa E-CK) Measurement Result IE.
• the E-CK ) Measurement Result IE may comprises one or more of the following values: an amplifier gain value (G amp), a downlink path loss value (L dl), a power value indicative of a radio head transmit power (Prh), a thermal noise power value (NO), a noise factor of a radio unit of the serving base station (NF_ru), inter-cell interference value (I_du), an uplink transmit power value indicating the transmit power of an uplink signal transmitted by the MCD (P ul mcd), a power value representative of the power of the uplink signal transmitted by the MCD as measured by the serving base station
• positioning node 140 transmits to MCD 120 a second request.
• the second request is an LPP message, such as a
• MCD 120 transmits a response and positioning node receives the response (step 808).
• the response is an LPP message (e.g., a ProvideLocationlnformation message), which includes an ECID-ProvideLocationlnformation IE.
• the ECK)- ProvideLocationlnformation IE comprises a received power value (P dl mcd) indicating a received power of a downlink signal transmitted by the serving radio head as measured by the MCD.
• positioning node 140 uses the values included in the messages received from the base station and the MCD to calculate L cable. In this way, positioning node 140 can perform step 706.
• FIG. 9 is a flow chart illustrating a process 900, according to some embodiments, that is performed by base station 104.
• base station 104 transmits to MCD 120 a request message (e.g., an
• step 904 base station 104 receives a response message transmitted by MCD
• the response message includes a received power value (P dl mcd) indicating a received power of a downlink signal transmitted by the serving radio head as measured by the MCD.
• the response message is an RRC message (e.g., a MeasurementReport message) that includes a MeasResults IE that includes the P dl mcd value.
• step 908 base station 104 transmits to positioning node 140 a message comprising the calculated L cable value.
• the message transmitted in step 908 may be an LPPa message, such as an LPPa E-CID Measurement Initiation Response message and or LPPa E-CID Measurement Report message, each of which includes an LPPa E-CK) Measurement Result IE that contains the calculated L cable value (if more than one L cable value is calculated, then the IE may contain all of the calculated L cable values).
• the base station uses the calculated L cable value(s) to select a set of one or more radio heads and, for each selected radio head, includes in the E-CID Measurement Result IE a radio head identifier for identifying the selected radio head.
• FIG. 10 is a flow chart illustrating a process 1000 for populating location fingerprint database 142 with location information.
• Process 1000 may begin in step 1002, where the location of MCD 120 is determined.
• the location determined in step 1002 may be high precision location that is determined using, for example, Assisted Global Positioning System (A- GPS) positioning. It may also be a pre-surveyed position in an indoor environment, for example defined on a map.
• A- GPS Assisted Global Positioning System
• a first fingerprint is generated using a cable length value representing the length of a cable connecting a radio head to a base station, wherein at the time the location of MCD 120 was determined in step 1002 the radio head was serving MCD 120.
• step 1006 the first fingerprint is associated with the location determined in step
• step 1008 a set of locations is determined wherein each location in the set is associated with a fingerprint matching the first fingerprint. For example, in step 1008 a database is searched using the first fingerprint to find all other locations that are also associated with the first fingerprint.
• a polygon is formed based on the determined set of locations, where each location in the set is associated with the same fingerprint.
• the polygon being defined by a set of three or more polygon coordinate vectors, each said polygon coordinate vector identifying a different vertex of the polygon.
• the first fingerprint is associated with location information that comprises at least the set of polygon coordinate vectors or a set of coordinates derived from the set of polygon coordinate vectors.
• location fingerprint database 142 which record includes a first field for storing the first fingerprint and a second field for storing the location information.
• fingerprints can be associated with location information, typically represented by polygons.
• FIG. 1 1 is a block diagram of a positioning node apparatus, such as positioning node 140.
• positioning node 140 may include or consist of: a computer system (CS) 1102, which may include one or more processors 1155 (e.g., a microprocessor) and/or one or more circuits, such as an application specific integrated circuit (ASIC), field- programmable gate arrays (FPGAs), a logic circuit, and the like; a network interface 1105 for connecting apparatus 104 to a network 110; and a data storage system 11 12, which may include one or more non-volatile storage devices and/or one or more volatile storage devices (e.g., random access memory (RAM)).
• CS computer system
• processors 1155 e.g., a microprocessor
• ASIC application specific integrated circuit
• FPGAs field- programmable gate arrays
• FIG. 1 1 is a block diagram of a positioning node apparatus, such as positioning node 140.
• CS computer system
• processors 1155 e.
• CPP 1141 includes or is a computer readable medium (CRM) 1142 storing a computer program (CP) 1 143 comprising computer readable instructions (CRI) 1 144 for performing steps described herein (e.g., one or more of the steps shown in FIGs. 2-10).
• CP 1 143 may include an operating system (OS) and/or application programs.
• CRM 1142 may include a non-transitory computer readable medium, such as, but not limited, to magnetic media (e.g., a hard disk), optical media (e.g., a DVD), solid state devices (e.g., random access memory (RAM), flash memory), and the like.
• the CRI 1 144 of computer program 1 143 is configured such that when executed by computer system 1102, the CRI causes the apparatus 1 140 to perform steps described above (e.g., steps described above and below with reference to the flow charts shown in the drawings).
• positioning node apparatus 140 may be configured to perform steps described herein without the need for a computer program. That is, for example, computer system 1102 may consist merely of one or more ASICs. Hence, the features of the embodiments described herein may be implemented in hardware and/or software.
• FIG. 12 is a block diagram of DU 105, according to some embodiments.
• DU apparatus 105 may include or consist of: a computer system (CS) 1202, which may include one or more processors 1255 (e.g., a microprocessor) and/or one or more circuits, such as an application specific integrated circuit (ASIC), field-programmable gate arrays (FPGAs), a logic circuit, and the like; a network interface 1205 for connecting DU 105 to network 130; one or more RU interfaces 1208 for connecting DU 105 to one more RUs; and a data storage system 1212, which may include one or more non-volatile storage devices and/or one or more volatile storage devices (e.g., random access memory (RAM)).
• CS computer system
• processors 1255 e.g., a microprocessor
• ASIC application specific integrated circuit
• FPGAs field-programmable gate arrays
• a data storage system 1212 which may include one or more non-volatile storage devices and/
• network interface 1205 and RU interface 1208 include a transceiver for transmitting data and receiving data.
• a computer program product (CPP) 1241 may be provided.
• CPP 1241 includes or is a computer readable medium (CRM) 1242 storing a computer program (CP) 1243 comprising computer readable instructions (CRI) 1244 for performing steps described herein (e.g., one or more of the steps shown in FIGs. 2-10).
• CP 1243 may include an operating system (OS) and/or application programs.
• CRM 1242 may include a non-transitory computer readable medium, such as, but not limited, to magnetic media (e.g., a hard disk), optical media (e.g., a DVD), solid state devices (e.g., random access memory (RAM), flash memory), and the like.
• magnetic media e.g., a hard disk
• optical media e.g., a DVD
• solid state devices e.g., random access memory (RAM), flash memory
• the CRI 1244 of computer program 1243 is configured such that when executed by computer system 1202, the CRI causes the apparatus 105 to perform steps described above (e.g., steps described above and below with reference to the flow charts shown in the drawings).
• apparatus 105 may be configured to perform steps described herein without the need for a computer program. That is, for example, computer system 1202 may consist merely of one or more ASICs. Hence, the features of the embodiments described herein may be implemented in hardware and/or software.
• RH i Radio head i of a maximum of n.
• P ul mcd The uplink transmit power as transmitted by the MCD [dBw].
• P dl mcd The measured received power in the downlink as measured by the MCD
• L ul The uplink path loss between the MCD and the serving radio head [dB].
• L dl The downlink path loss between the serving radio head and the MCD [dB].
• Prh The transmit power of the radio head [dBw].
• G amp The gain of the uplink amplifier of the radio head [dB].
• SINR mcd du The signal to noise and interference ratio of the MCD, as measured in the DU [dB]
• P ul mcd du The MCD power, as measured in the DU [dBw].
• RRC Radio Resource Control

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• 2015
  • 2015-06-22 WO PCT/SE2015/050720 patent/WO2016122365A1/en active Application Filing
  • 2015-06-22 EP EP15880332.0A patent/EP3250939A4/de not_active Withdrawn

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