195:(BTS) towers, in the case on CNP service coverage area). Without any of those resources, it can't connect to the A-GPS servers usually provided by CNPs. On the other hand, a mobile device with a GPS chipset requires no data connection to capture and process GPS data into a position solution, since it receives data directly from the GPS satellites and is able to calculate a position fix itself. However, the availability of a data connection can provide assistance to improve the performance of the GPS chip on the mobile device.
20:
105:
to calculate its position. The data rate of the satellite signal is only 50 bit/s, so downloading orbital information like ephemerides and the almanac directly from satellites typically takes a long time, and if the satellite signals are lost during the acquisition of this information, it is
288:
is an allied technology that addresses some of these issues in a way that does not require additional infrastructure. However, unlike some forms of A-GPS, high-sensitivity GPS cannot provide a fix instantaneously when the GPS receiver has been off for some time.
406:
SUPL Position
Calculation Function (SPCF), which lets the client or the server ask for the client's location. The server-generated location may result from MSA or from mobile cell. If a MSB (SET based) mode is used, the client reports its location to the server
190:
and no GPS acquisition, tracking, and positioning engine only works when it has an internet connection to an ISP/CNP, where the position fix is calculated offboard the device itself. It doesn't work in areas with no coverage or internet link (or nearby
146:
for GPS data. These A-GPS servers download the orbital information from the satellite and store it in the database. An A-GPS-capable device can connect to these servers and download this information using mobile-network radio bearers such as
388:
infrastructure. Consequently, its application extends beyond the original intended use of mobile devices and may be used by general-purpose computers. SUPL 3.0 legitimizes such use by adding admission for WLAN and broadband connections.
257:
A typical A-GPS-enabled receiver uses a data connection (Internet or other) to contact the assistance server for aGPS information. If it also has functioning autonomous GPS, it may use standalone GPS, which is sometimes slower on
171:. Usually the data rate of these bearers is high, hence downloading orbital information takes less time. Utilizing this system can come at a cost to the user. For billing purposes, network providers often count this as a
253:
Not every A-GNSS server provides MSA mode operation due to the computational cost and the declining number of mobile terminals incapable of performing their own calculations. Google's SUPL server is one that doesn't.
262:, but does not depend on the network, and therefore can work beyond network range and without incurring data-usage fees. Some A-GPS devices do not have the option of falling back to standalone or autonomous GPS.
411:
The specifics of communication is defined in the ULP (Userplane
Location Protocol) substandard of SUPL suite. As of December 2018, GNSS systems supported include GPS, Galileo, GLONASS, and BeiDou.
46:(GNSS). A-GNSS works by providing the necessary data to the device via a radio network instead of the slow satellite link, essentially "warming up" the receiver for a fix. When applied to
106:
discarded and the standalone system has to start from scratch. In exceptionally poor signal conditions, for example in urban areas, satellite signals may exhibit
807:
782:
751:
119:
620:
403:
SUPL Reference
Retrieval Function (SRRF), which tells the server to prepare the information mentioned above by receiving from the satellites.
767:
668:
236:
The assistance server has a good satellite signal and plentiful computation power, so it can compare fragmentary signals relayed to it.
217:
or almanac for the GPS satellites to the GPS receiver, enabling the GPS receiver to lock to the satellites more rapidly in some cases.
792:
467:
322:
247:
conditions and other conditions affecting the GPS signal than the GPS receiver alone, enabling more precise calculation of position.
122:
and must wait for better satellite reception. A regular GPS unit may need as long as 12.5 minutes (the time needed to download the
576:
186:(or CNP, in the case of CP/mobile-phone device linked to a cellular network provider data service). A mobile device with just an
380:
The SUPL (Secure User Plane
Location) protocol, unlike its control-plane equivalents restricted to mobile networks, runs on the
187:
777:
233:
The device captures a snapshot of the GPS signal, with approximate time, for the server to later process into a position.
997:
756:
613:
400:
SUPL Assistance
Delivery Function (SADF), which provides the basic information sent to the device in both A-GNSS modes.
43:
82:
135:
849:
445:
772:
653:
946:
802:
787:
691:
673:
606:
797:
696:
506:
683:
285:
992:
577:"Secure User Plane Location Architecture - Candidate Version 3.0 [OMA-AD-SUPL-V3_0-20110920-C]"
368:
325:– 3GPP defined RRLP (Radio Resource Location Protocol) to support positioning protocol on GSM networks.
663:
396:
and billing. The A-GNSS functions are defined in the SUPL Positioning
Functional Group. It includes:
315:
Defined by the 3GPP for various generations of mobile phone systems. These protocols are defined for
279:
183:
176:
648:
589:
347:
271:
192:
160:
706:
297:
A-GPS protocols are part of
Positioning Protocol defined by two different standardization bodies,
111:
336:
420:
275:
115:
107:
98:
123:
629:
302:
478:
8:
971:
553:
182:
To be precise, A-GPS features depend mostly on an
Internet network or connection to an
139:
956:
743:
701:
316:
259:
39:
35:
425:
364:
357:
78:
961:
915:
230:
Calculation of position by the server using information from the GPS receiver.
986:
905:
309:
102:
880:
527:
86:
89:
to make cell phone location data available to emergency call dispatchers.
930:
925:
920:
885:
722:
244:
172:
270:
Many mobile phones combine A-GPS and other location services, including
951:
910:
870:
865:
598:
393:
38:
system that often significantly improves the startup performance—i.e.,
966:
890:
875:
823:
240:
214:
143:
126:) to resolve the problem and be able to provide a correct location.
895:
730:
381:
329:
761:
392:
Actions defined by SUPL 3.0 include a wide range of services like
335:
RRC position protocol – 3GPP defined this protocol as part of the
118:
used in poor conditions can't fix a position because of satellite
900:
658:
319:
networks. The following positioning protocols have been defined.
643:
385:
844:
164:
156:
371:(SUPL) protocol have been defined, from version 1.0 to 3.0.
340:
298:
168:
152:
16:
System to improve the time-to-first-fix of a GNSS receiver
148:
47:
528:"iPhone Secrets and iPad Secrets and iPod Touch Secrets"
19:
363:
Defined by the OMA to support positioning protocols in
346:
LPP – 3GPP defined LPP or LTE positioning protocol for
210:
Information used to acquire satellites more quickly.
332:
family defined this protocol for CDMA 2000 networks.
114:
by meteorological conditions or tree canopies. Some
81:, as its development was accelerated by the U.S.
984:
551:
614:
446:"Assisted GPS: A Low-Infrastructure Approach"
468:"NavCen GPS User. 3.5.3 Almanac Collection"
77:A-GPS is extensively used with GPS-capable
621:
607:
163:or even using other radio bearers such as
110:where signals skip off structures, or are
552:Fernández-Prades, Carles (17 July 2022).
175:, which can cost money, depending on the
628:
18:
571:
569:
567:
265:
243:towers allow better knowledge of local
239:Accurate, surveyed coordinates for the
985:
500:
498:
203:Assistance falls into two categories:
602:
220:The network can provide precise time.
198:
564:
495:
13:
44:global navigation satellite system
14:
1009:
101:requires orbital data about the
504:
367:networks. Three generations of
545:
520:
460:
438:
1:
947:Geographic information system
692:Personal navigation assistant
431:
227:Mobile Station Assisted (MSA)
92:
66:). Other local names include
697:Automotive navigation system
554:"Global receiver parameters"
292:
129:
7:
414:
188:L1 front-end radio receiver
124:GPS almanac and ephemerides
10:
1014:
448:. GPS World. March 1, 2002
369:Secure User Plane Location
303:Open Mobile Alliance (OMA)
207:Mobile Station Based (MSB)
58:(abbreviated generally as
998:Global Positioning System
939:
858:
832:
816:
742:
715:
682:
636:
280:hybrid positioning system
276:cell-site multilateration
116:standalone GPS navigators
272:Wi-Fi positioning system
193:base transceiver station
375:
590:suite of all standards
24:
421:Mobile phone tracking
108:multipath propagation
62:and less commonly as
22:
630:Satellite navigation
584:Open Mobile Alliance
286:High-Sensitivity GPS
266:Related technologies
972:GPS animal tracking
859:Geographic services
199:Modes of operation
25:
993:Mobile technology
980:
979:
744:GNSS augmentation
260:time to first fix
138:deploys an A-GPS
50:, it is known as
40:time-to-first-fix
36:GNSS augmentation
1005:
788:QZSS / Michibiki
623:
616:
609:
600:
599:
593:
587:
581:
573:
562:
561:
549:
543:
542:
540:
539:
524:
518:
517:
515:
514:
502:
493:
492:
490:
489:
483:
477:. Archived from
475:Navcen.uscvg.gov
472:
464:
458:
457:
455:
453:
442:
426:GNSS enhancement
317:circuit switched
278:and sometimes a
136:network operator
70:for Galileo and
1013:
1012:
1008:
1007:
1006:
1004:
1003:
1002:
983:
982:
981:
976:
935:
854:
828:
812:
738:
735:CellGuide ACLYS
711:
678:
632:
627:
597:
596:
579:
575:
574:
565:
550:
546:
537:
535:
526:
525:
521:
512:
510:
505:Low, Aloysius.
503:
496:
487:
485:
481:
470:
466:
465:
461:
451:
449:
444:
443:
439:
434:
417:
378:
365:packet switched
295:
268:
201:
132:
120:signal fracture
95:
87:911 requirement
79:cellular phones
17:
12:
11:
5:
1011:
1001:
1000:
995:
978:
977:
975:
974:
969:
964:
962:Geoinformatics
959:
954:
949:
943:
941:
940:Related topics
937:
936:
934:
933:
928:
923:
918:
916:NASA WorldWind
913:
908:
903:
898:
893:
888:
883:
878:
873:
868:
862:
860:
856:
855:
853:
852:
847:
842:
836:
834:
830:
829:
827:
826:
820:
818:
814:
813:
811:
810:
805:
800:
795:
790:
785:
780:
775:
770:
765:
759:
754:
748:
746:
740:
739:
737:
736:
733:
728:
725:
719:
717:
713:
712:
710:
709:
704:
699:
694:
688:
686:
680:
679:
677:
676:
671:
666:
661:
656:
651:
646:
640:
638:
634:
633:
626:
625:
618:
611:
603:
595:
594:
586:. 20 Sep 2011.
563:
544:
519:
494:
459:
436:
435:
433:
430:
429:
428:
423:
416:
413:
409:
408:
404:
401:
377:
374:
373:
372:
361:
354:
353:
352:
351:
344:
333:
326:
313:
294:
291:
267:
264:
251:
250:
249:
248:
237:
234:
228:
224:
223:
222:
221:
218:
213:It can supply
208:
200:
197:
134:In A-GPS, the
131:
128:
94:
91:
15:
9:
6:
4:
3:
2:
1010:
999:
996:
994:
991:
990:
988:
973:
970:
968:
965:
963:
960:
958:
955:
953:
950:
948:
945:
944:
942:
938:
932:
929:
927:
924:
922:
919:
917:
914:
912:
909:
907:
906:OpenStreetMap
904:
902:
899:
897:
894:
892:
889:
887:
884:
882:
879:
877:
874:
872:
869:
867:
864:
863:
861:
857:
851:
848:
846:
843:
841:
838:
837:
835:
831:
825:
822:
821:
819:
815:
809:
806:
804:
801:
799:
796:
794:
791:
789:
786:
784:
781:
779:
776:
774:
771:
769:
766:
763:
760:
758:
755:
753:
750:
749:
747:
745:
741:
734:
732:
729:
726:
724:
721:
720:
718:
714:
708:
705:
703:
700:
698:
695:
693:
690:
689:
687:
685:
681:
675:
672:
670:
669:IRNSS / NAVIC
667:
665:
662:
660:
657:
655:
652:
650:
647:
645:
642:
641:
639:
635:
631:
624:
619:
617:
612:
610:
605:
604:
601:
591:
585:
578:
572:
570:
568:
559:
555:
548:
533:
529:
523:
508:
501:
499:
484:on 2008-09-10
480:
476:
469:
463:
447:
441:
437:
427:
424:
422:
419:
418:
412:
405:
402:
399:
398:
397:
395:
390:
387:
383:
370:
366:
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359:
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355:
349:
345:
342:
339:standard for
338:
334:
331:
327:
324:
321:
320:
318:
314:
311:
310:Control Plane
308:
307:
306:
304:
300:
290:
287:
283:
281:
277:
273:
263:
261:
255:
246:
242:
238:
235:
232:
231:
229:
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225:
219:
216:
212:
211:
209:
206:
205:
204:
196:
194:
189:
185:
180:
178:
174:
170:
166:
162:
158:
154:
150:
145:
141:
137:
127:
125:
121:
117:
113:
109:
104:
100:
90:
88:
84:
80:
75:
74:for BeiDou.
73:
69:
65:
61:
57:
56:augmented GPS
53:
49:
45:
41:
37:
33:
29:
28:Assisted GNSS
21:
881:Google Earth
839:
583:
557:
547:
536:. Retrieved
534:. 2010-09-30
531:
522:
511:. Retrieved
486:. Retrieved
479:the original
474:
462:
450:. Retrieved
440:
410:
391:
379:
296:
284:
269:
256:
252:
215:orbital data
202:
181:
144:cache server
133:
96:
76:
71:
67:
63:
59:
55:
52:assisted GPS
51:
42:(TTFF)—of a
31:
27:
26:
23:Assisted GPS
931:Yandex Maps
926:Yahoo! Maps
921:ViaMichelin
886:Google Maps
727:SiRFatlasIV
723:SiRFstarIII
702:GPS tracker
245:ionospheric
173:data access
987:Categories
952:Geocaching
911:Petal Maps
871:Baidu Maps
866:Apple Maps
833:Technology
707:GPS logger
538:2017-04-02
532:Edepot.com
513:2017-04-02
488:2017-04-02
432:References
394:geofencing
358:User Plane
328:TIA 801 –
103:satellites
99:GPS device
93:Background
967:Geomatics
957:Geocoding
891:Here WeGo
876:Bing Maps
817:Protocols
764:(retired)
350:networks.
293:Standards
241:cell site
130:Operation
896:MapQuest
798:StarFire
793:SouthPAN
716:Chipsets
558:GNSS-SDR
507:"Phones"
415:See also
407:instead.
382:Internet
360:Protocol
343:network.
330:CDMA2000
312:Protocol
112:weakened
72:A-Beidou
901:OpenCPN
684:Devices
659:GLONASS
654:Galileo
637:Systems
452:11 June
68:A-GANSS
34:) is a
644:BeiDou
509:. CNET
386:TCP/IP
177:tariff
140:server
97:Every
32:A-GNSS
845:S-GPS
840:A-GPS
783:NTRIP
768:JPALS
762:GPS·C
757:GAGAN
752:EGNOS
649:DORIS
580:(PDF)
482:(PDF)
471:(PDF)
165:Wi-Fi
157:WCDMA
60:A-GPS
824:NMEA
808:SDCM
803:WAAS
778:MSAS
773:LAAS
674:QZSS
454:2008
376:SUPL
341:UMTS
323:RRLP
301:and
299:3GPP
274:and
169:LoRa
153:CDMA
142:, a
64:aGPS
850:RTK
731:MTK
664:GPS
384:'s
348:LTE
337:RRC
184:ISP
167:or
161:LTE
149:GSM
85:'s
83:FCC
54:or
48:GPS
989::
582:.
566:^
556:.
530:.
497:^
473:.
305:.
282:.
179:.
159:,
155:,
151:,
622:e
615:t
608:v
592:)
588:(
560:.
541:.
516:.
491:.
456:.
30:(
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