LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 1 Product name Description Version MC-1613-G Standalone multiple GNSS module 0.2 Introduction LOCOSYS MC-1613-G is a complete standalone GNSS module. The module can simultaneously acquire and track multiple satellite constellations that include GPS, GLONASS, GALILEO, QZSS and SBAS. It features low power and small form factor. Besides, it can provide you with superior sensitivity and performance even in urban canyon and dense foliage environment. This module supports hybrid ephemeris prediction to achieve faster cold start. One is self-generated ephemeris prediction (called EASY) that is no need of both network assistance and host CPU’s intervention. This is valid for up to 3 days and updates automatically from time to time when GNSS module is powered on and satellites are available. The other is server-generated ephemeris prediction (called EPO) that gets from an internet server. This is valid for up to 14 days. Both ephemeris predictions are stored in the on-board flash memory and perform a cold start time less than 15 seconds. 2 Features 3 MediaTek high sensitivity solution Support GPS, GLONASS, GALILEO and QZSS Capable of SBAS (WAAS, EGNOS, MSAS, GAGAN) Support 99-channel GNSS Low power consumption Fast TTFF at low signal level Built-in 12 multi-tone active interference canceller Free hybrid ephemeris prediction to achieve faster cold start Built-in data logger Up to 10 Hz update rate ±11ns high accuracy time pulse (1PPS) Indoor and outdoor multi-path detection and compensation Small form factor 15.9 x 13.1 x 2.2 mm SMD type with stamp holes; RoHS compliant Application Personal positioning and navigation Automotive navigation Marine navigation Page 1/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 36 GND 35 NC 34 NC 33 GND 32 NC 31 RX 30 TX Fig 3-1 System block diagram. 18 NC 17 NC 16 NC 15 GND 14 NC 13 /RESET 12 NC Fig 3-2 Typical application circuit that uses an active antenna Page 2/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 3.3V GPS passive antenna Impedance 50 ohm 2~4.3V Battery keep alive to get hot start and AGPS start output 3.3V 36 GND 35 NC 34 NC 33 GND 32 NC 31 RX 30 TX 1 2 3 4 5 29 NC 28 NC 27 NC 26 NC 25 NC RFIN GND NC NC V_BCKP 6 GND 7 8 9 10 11 NC NC NC NC VCC MC-1613-G GND VCC GND Micro processor 24 23 NC 22 NC 21 NC 20 1PPS 19 NC 18 NC 17 NC 16 NC 15 GND 14 NC 13 /RESET 12 NC LDO TX RX Fig 3-3 Typical application circuit that uses a passive antenna. Page 3/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 4 GNSS receiver Chip MediaTek MT3333 Frequency GPS, GALILEO, QZSS: L1 1575.42MHz, C/A code GLONASS: L1 1598.0625MHz ~ 1605.375MHz, C/A code Channels Support 99 channels (33 Tracking, 99 Acquisition) Update rate 1Hz default, up to 10Hz Sensitivity Acquisition Time Tracking up to -165dBm (with external LNA) Cold start up to -148dBm (with external LNA) Hot start (Open Sky) < 1s (typical) Hot start (Indoor) < 30s 32s (typical) without AGPS Cold Start (Open Sky) < 15s (typical) with AGPS (hybrid ephemeris prediction) Position Accuracy Autonomous 3m (2D RMS). SBAS 2.5m (depends on accuracy of correction data). Max. Altitude < 50,000 m Max. Velocity < 515 m/s Protocol Support 9600 bps(1), 8 data bits, no parity, 1 stop bits (default) NMEA 0183 ver 3.01 1Hz: GGA, GLL, GSA, GSV, RMC, VTG Note 1: Both baud rate and output message rate are configurable to be factory default. 5 Software interface 5.1 NMEA output message Table 5.1-1 NMEA output message NMEA record Description GGA Global positioning system fixed data GLL Geographic position - latitude/longitude GSA GNSS DOP and active satellites GSV GNSS satellites in view RMC Recommended minimum specific GNSS data VTG Course over ground and ground speed GGA--- Global Positioning System Fixed Data Table 5.1-2 contains the values for the following example: $GPGGA,183015.000,2503.7123,N,12138.7446,E,2,16,0.68,123.2,M,15.3,M,0000,0000*66 Table5.1- 2 GGA Data Format Name Example Units Description Page 4/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ Message ID $GPGGA GGA protocol header UTC Time 183015.000 hhmmss.sss Latitude 2503.7123 ddmm.mmmm N/S indicator N N=north or S=south Longitude 12138.7446 dddmm.mmmm E/W Indicator E E=east or W=west Position Fix Indicator 2 See Table 5.1-3 Satellites Used 16 Range 0 to 33 HDOP 0.68 Horizontal Dilution of Precision MSL Altitude 123.2 mters Units M mters Geoid Separation 15.3 mters Units M mters Age of Diff. Corr. 0000 second Diff. Ref. Station ID 0000 Checksum *66 <CR> <LF> Null fields when DGPS is not used End of message termination Table 5.1-3 Position Fix Indicators Value Description 0 Fix not available or invalid 1 GPS SPS Mode, fix valid 2 Differential GPS, SPS Mode, fix valid 3-5 Not supported 6 Dead Reckoning Mode, fix valid GLL--- Geographic Position – Latitude/Longitude Table 5.1-4 contains the values for the following example: $GPGLL,2503.7123,N,12138.7446,E,183015.000,A,D*59 Table 5.1-4 GLL Data Format Name Example Units Description Message ID $GPGLL GLL protocol header Latitude 2503.7123 ddmm.mmmm N/S indicator N N=north or S=south Longitude 12138.7446 dddmm.mmmm E/W indicator E E=east or W=west UTC Time 183015.000 hhmmss.sss Page 5/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ Status A Mode D Checksum *59 A=data valid or V=data not valid A=autonomous, D=DGPS, E=DR, N=Data not valid, R=Coarse Position, S=Simulator <CR> <LF> End of message termination GSA---GNSS DOP and Active Satellites Table 5.1-5 contains the values for the following example: $GNGSA,A,3,18,193,21,09,12,22,27,15,25,14,,,1.44,0.68,1.27*2F $GNGSA,A,3,76,72,77,75,66,65,,,,,,,1.44,0.68,1.27*12 Table 5.1-5 GSA Data Format Name Example Units Description Message ID $GNGSA GSA protocol header Mode 1 A See Table 5.1-6 Mode 2 3 See Table 5.1-7 ID of satellite used 18 Sv on Channel 1 ID of satellite used 193 Sv on Channel 2 …. …. ID of satellite used Sv on Channel N PDOP 1.44 Position Dilution of Precision HDOP 0.68 Horizontal Dilution of Precision VDOP 1.27 Vertical Dilution of Precision Checksum *2F <CR> <LF> End of message termination Table 5.1-6 Mode 1 Value Description M Manual- forced to operate in 2D or 3D mode A Automatic-allowed to automatically switch 2D/3D Table 5.1-7 Mode 2 Value Description 1 Fix not available 2 2D 3 3D GSV---GNSS Satellites in View Table 5.1-8 contains the values for the following example: $GPGSV,3,1,11,18,67,344,48,09,55,031,50,42,54,142,40,193,47,174,45*4D Page 6/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ $GPGSV,3,2,11,21,44,219,46,27,39,035,48,12,34,131,44,15,30,057,46*76 $GPGSV,3,3,11,22,27,319,47,14,22,285,42,25,19,171,40*44 $GLGSV,2,1,07,76,71,201,44,65,57,041,40,75,48,028,39,72,27,108,39*68 $GLGSV,2,2,07,66,25,333,43,77,17,207,37,81,02,280,29*5C Table 5.1-8 GSV Data Format Name Example Message ID $GPGSV Units GSV protocol header (GPGSV and GLGSV) Total number of messages1 3 Message number 1 Description Range 1 to 6 1 Range 1 to 6 Satellites in view 11 Satellite ID 18 Elevation 67 degrees Channel 1 (Range 00 to 90) Azimuth 344 degrees Channel 1 (Range 000 to 359) SNR (C/No) 48 dB-Hz Channel 1 (Range 00 to 99, null when not tracking) Satellite ID 09 Elevation 55 degrees Channel 4 (Range 00 to 90) Azimuth 031 degrees Channel 4 (Range 000 to 359) SNR (C/No) 50 dB-Hz Channel 4 (Range 00 to 99, null when not tracking) Checksum *4D Channel 1 (Range 01 to 196) Channel 4 (Range 01 to 196) <CR> <LF> End of message termination 1. Depending on the number of satellites tracked multiple messages of GSV data may be required. RMC---Recommended Minimum Specific GNSS Data Table 5.1-9 contains the values for the following example: $GNRMC,183015.000,A,2503.7123,N,12138.7446,E,0.01,34.92,270812,,,D*43 Table 5.1-9 RMC Data Format Name Example Units Description Message ID $GNRMC RMC protocol header (GNRMC or GPRMC) UTC Time 183015.000 hhmmss.sss Status A A=data valid or V=data not valid Latitude 2503.7123 ddmm.mmmm N/S Indicator N N=north or S=south Longitude 12138.7446 dddmm.mmmm E/W Indicator E E=east or W=west Speed over ground 0.01 knots Course over ground 34.92 degrees Date 270812 True ddmmyy Page 7/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ degrees Magnetic variation Variation sense E=east or W=west (Not shown) Mode D Checksum *43 A=autonomous, D=DGPS, E=DR, N=Data not valid, R=Coarse Position, S=Simulator <CR> <LF> End of message termination VTG---Course Over Ground and Ground Speed Table 5.1-10 contains the values for the following example: $GPVTG,34.92,T,,M,0.01,N,0.02,K,D*07 Table 5.1-10 VTG Data Format Name Example Message ID $GPVTG Course over ground 34.92 Reference T Units VTG protocol header degrees Reference M Speed over ground 0.01 Units N Speed over ground 0.02 Units K Mode D Checksum *07 Measured heading True degrees Course over ground Description Measured heading Magnetic knots Measured speed Knots km/hr Measured speed Kilometer per hour A=autonomous, D=DGPS, E=DR, N=Data not valid, R=Coarse Position, S=Simulator <CR> <LF> End of message termination 5.2 Proprietary NMEA input/output message Please refer to MTK proprietary message. 5.3 Examples to configure the power mode of GNSS module The GNSS module supports different power modes that user can configure by issuing software commands. 5.3.1 Standby mode User can issue software command to make GNSS module go into standby mode that consumes less than 200uA current. GNSS module will be awaked when receiving any byte. The following flow chart is an example to make GNSS module go into standby mode and then wake up. Page 8/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ Start GPS module is powered on and in normal operation mode Change GPS to standby mode Wake up GPS module unsigned char StandbyMode[] = {"$PMTK161,0*28\x0D\x0A"}; Yes Issue any byte to wake up GPS module No GPS module will return {"$PMTK010,001*2E\x0D\x0A"} and start normal operation. End 5.3.2 Periodic mode When GNSS module is commanded to periodic mode, it will be in operation and standby periodically. Its status of power consumption is as below chart. The following flow chart is an example to make GNSS module go into periodic mode Page 9/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ and then back to normal operation mode. Start GPS module is powered on Change GPS to periodic mode with 3000ms on and 12000ms standby if position fix is available, otherwise (18000, 72000) ms will be applied. unsigned char PeriodicMode[] = {"$PMTK225,2,3000,12000,18000,72000*15\x0D\x0A"}; Note: minimum on time is 2000ms. maximum standby time is 518400000ms (6 days) GPS module will return message "$PMTK001,225,3*35\x0D\x0A" if command is accepted. Set GPS to normal operation mode? Yes GPS is in standby now Yes Issue any byte to GPS and wait it awake No No Issue command of normal operation mode unsigned char NormalMode[] = {"$PMTK225,0*2B\x0D\x0A"}; GPS module will return message "$PMTK001,225,3*35\x0D\x0A" if command is accepted. End GPS is in periodic mode End GPS is in normal mode 5.3.3 AlwaysLocateTM mode AlwaysLocateTM is an intelligent controller of periodic mode. Depending on the environment and motion conditions, GNSS module can adaptively adjust working/standby time to achieve balance of positioning accuracy and power consumption. In this mode, the host CPU does not need to control GNSS module until the host CPU needs the GNSS position data. The following flow chart is an example to make GNSS module go into AlwaysLocateTm mode and then back to normal operation mode. Page 10/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ Note: AlwaysLocateTM is a trade mark of MTK. Start GPS module is powered on Change GPS to AlwaysLocate mode unsigned char AlwaysLocateMode[] = {"$PMTK225,8*23\x0D\x0A"}; Yes GPS module will return message "$PMTK001,225,3*35\x0D\x0A" if command is accepted. Request a GPS position data No Yes Issue any byte to get GPS position data No Set GPS to normal operation mode? Change GPS back to AlwaysLocate mode Yes Issue any byte to GPS and wait it awake No Set GPS to normal operation mode unsigned char NormalMode[] = {"$PMTK225,0*2B\x0D\x0A"}; End GPS is in normal mode 5.4 Data logger The GNSS module has internal flash memory for logging GNSS data. The configurations Page 11/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ include time interval, distance, speed, logging mode, and … etc. For more information, please contact us. 5.5 Examples to configure the update rate of GNSS module The GNSS module supports up to 10Hz update rate that user can configure by issuing software commands. Note that the configurations by software commands are stored in the battery-backed SRAM that is powered through VBACKUP pin. Once it drains out, the default/factory settings will be applied. Due to the transmitting capacity per second of the current baud rate, GNSS module has to be changed to higher baud rate for high update rate of position fix. The user can use the following software commands to change baud rate. Baud rate Software command Factory default $PMTK251,0*28<CR><LF> 4800 $PMTK251,4800*14<CR><LF> 9600 $PMTK251,9600*17<CR><LF> 19200 $PMTK251,19200*22<CR><LF> 38400 $PMTK251,38400*27<CR><LF> 57600 $PMTK251,57600*2C<CR><LF> 115200 $PMTK251,115200*1F<CR><LF> Note: <CR> means Carriage Return, i.e. 0x0D in hexadecimal. <LF> means Line Feed, i.e. 0x0A in hexadecimal. If the user does not want to change baud rate, you can reduce the output NMEA sentences by the following software commands. NMEA sentence Software command Factory default $PMTK314,-1*04<CR><LF> Only GLL at 1Hz $PMTK314,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29<CR><LF> Only RMC at 1Hz $PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29<CR><LF> Only VTG at 1Hz $PMTK314,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29<CR><LF> Only GGA at 1Hz $PMTK314,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29<CR><LF> Only GSA at 1Hz $PMTK314,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29<CR><LF> Only GSV at 1Hz $PMTK314,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0*29<CR><LF> Only ZDA at 1Hz $PMTK314,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0*29<CR><LF> RMC, GGA, GSA at 1Hz and GSV at $PMTK314,0,1,0,1,1,5,0,0,0,0,0,0,0,0,0,0,0,0,0*2C<CR><LF> 0.2Hz If the command is correct and executed, GNSS module will output message $PMTK001,314,3*36<CR><LF> Page 12/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ After the GNSS module is changed to higher baud rate or reduced NMEA sentence, the user can configure it to high update rate of position fix by the following commands. Interval of position fix (1) Software command Every 100ms (10Hz) $PMTK220,100*2F<CR><LF> Every 200ms (5Hz) $PMTK220,200*2C<CR><LF> Every 500ms (2Hz) $PMTK220,500*2B<CR><LF> Every 1000ms (1Hz) $PMTK220,1000*1F<CR><LF> Every 2000ms (0.5Hz)(2) $PMTK220,2000*1C<CR><LF> If the command is correct and executed, GNSS module will output message $PMTK001,220,3*30<CR><LF> Note 1: The minimum interval of position fix is 100ms, i.e. the maximum update rate is 10Hz. Note 2: The current consumption is the same with the update rate of 1Hz. 6 Pin assignment and descriptions Table 6-1 Pin descriptions Pin # Name 1 RFIN Type Description I GNSS RF signal input Note 1 Page 13/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 2 GND P 3 NC Not connected 4 NC Not connected 5 V_BCKP P 6 GND P 7 NC Not connected 8 NC Not connected 9 NC Not connected 10 NC Not connected 11 VCC 12 NC Not connected 13 /RESET Reset input, active low. GNSS module has internal power-on reset circuit, user can leave this pin floating. 14 NC 15 GND 16 NC Not connected 17 NC Not connected 18 NC Not connected 19 NC Not connected 20 1PPS 21 NC Not connected 22 NC Not connected 23 NC Not connected 24 GND 25 NC Not connected 26 NC Not connected 27 NC Not connected 28 NC Not connected 29 NC Not connected 30 TX O Serial output (Default NMEA) 31 RX I Serial input (Default NMEA) 32 NC 33 GND 34 NC Not connected 35 NC Not connected P I Ground Backup battery supply voltage This pin must be powered to enable the module. 2 Ground DC supply voltage Not connected P O P Ground Pulse per second (default 100ms pulse/sec) Ground Not connected P Ground Page 14/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 36 GND P Ground <Note> 1. RFIN does not have short circuit protection. 2. In order to get AGPS (Long Term Orbit) advantage, this pin must be always powered during the period of effective AGPS. Page 15/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 7 DC & Temperature characteristics 7.1 Absolute maximum ratings Parameter Symbol Ratings Units VCC 4.3 V Input Backup Battery Voltage V_BCKP 4.3 Operating Temperature Range Topr -40 ~ 85 V ℃ Storage Temperature Range Tstg -40 ~ 85 ℃ Input Voltage 7.2 DC Electrical characteristics Parameter Input Voltage Input Backup Battery Voltage Symbol Conditions Min. Typ. Max. Units VCC 3.0 3.3 4.3 V V_BCKP 2.0 4.3 V TBD(1) VCC = 3.3V, w/o active antenna, Peak Acquisition Tracking Standby 27 23(2) TBD mA mA mA uA VCC = 0V 6 uA Supply Current Iss Backup Battery Current Ibat High Level Input Voltage VI H 2.0 3.6 V Low Level Input Voltage VI L -0.3 0.8 V High Level Input Current IIH no pull-up or down -1 1 uA Low Level Input Current IIL no pull-up or down -1 1 uA High Level Output Voltage VOH Low Level Output Voltage VOL High Level Output Current IOH 2 mA Low Level Output Current IOL 2 mA 2.4 V 0.4 V Note 1. This happens when downloading AGPS data to MC-1613-G. Note 2. Measured when position fix (1Hz) is available, input voltage is 3.3V and the function of self-generated ephemeris prediction is inactive. 7.3 Temperature characteristics Parameter Symbol Min. Typ. Max. Operating Temperature Topr -40 - 85 Units ℃ Storage Temperature Tstg -40 25 85 ℃ Page 16/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 8 Mechanical specification 8.1 Outline dimensions 8.2 Recommended land pattern dimensions Page 17/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ 9 Reel packing information Page 18/19 © 2010 LOCOSYS Technology Inc. LOCOSYS Technology Inc. 20F.-13, No.79, Sec. 1, Xintai 5th Rd., Xizhi City, Taipei County 221, Taiwan ℡ 886-2-8698-3698 886-2-8698-3699 www.locosystech.com/ Document change list Revision 0.2 Preliminary Page 19/19 © 2010 LOCOSYS Technology Inc.