EP1240769A2 - Time synchronization in a cellular network device - Google Patents

Time synchronization in a cellular network device

Info

Publication number
EP1240769A2
EP1240769A2 EP00988233A EP00988233A EP1240769A2 EP 1240769 A2 EP1240769 A2 EP 1240769A2 EP 00988233 A EP00988233 A EP 00988233A EP 00988233 A EP00988233 A EP 00988233A EP 1240769 A2 EP1240769 A2 EP 1240769A2
Authority
EP
European Patent Office
Prior art keywords
time
user
current local
previous
updating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00988233A
Other languages
German (de)
English (en)
French (fr)
Inventor
Murtuza Chhatriwala
Christine Park
Clarence Wong
Jason B. Kenagy
Weining Ruan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Qualcomm Inc
Original Assignee
Qualcomm Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Qualcomm Inc filed Critical Qualcomm Inc
Publication of EP1240769A2 publication Critical patent/EP1240769A2/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G04HOROLOGY
    • G04RRADIO-CONTROLLED TIME-PIECES
    • G04R20/00Setting the time according to the time information carried or implied by the radio signal
    • G04R20/14Setting the time according to the time information carried or implied by the radio signal the radio signal being a telecommunication standard signal, e.g. GSM
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/24Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M1/00Substation equipment, e.g. for use by subscribers
    • H04M1/72Mobile telephones; Cordless telephones, i.e. devices for establishing wireless links to base stations without route selection
    • H04M1/724User interfaces specially adapted for cordless or mobile telephones
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W56/00Synchronisation arrangements

Definitions

  • the present invention generally relates to the field of wireless communications. More particularly, the present invention relates to a novel system that automatically provides synchronization time to a digital device configured to receive data transmitted across a wireless communications network.
  • PDAs PDAs
  • a cellular network is defined as a mobile communications system, which divides its coverage area into contiguous geographic areas referred to as cell grids 11, 13, 15. Each ⁇ rid services a specific geographic region within the network, includes one base station (BS) 5, 7, 9.
  • BSs consist of, among other components, a processor, a receiver, and a transmitter (not shown) and function like a repeater, receiving calls from users and passing the received calls to other users within the grid or passing the calls to a land line.
  • a mobile switching center (MSC) 3 controls the operation the BSs 5, 7, 9 and provides the wireless cellular network with an interface to the public switched telephone network (PSTN) 4.
  • PSTN public switched telephone network
  • CDMA Code Division Multiple Access
  • TIA/EIA IS-95 Telecommunications Industry Association/Electronics Industries Association Interim Standard-95
  • Wireless communication systems employing this technology assign a unique code to communication signals and spread these communication signals across a common (wideband) spread spectrum bandwidth.
  • the receiving apparatus in a CDMA system has the correct code, it can successfully detect and select its communication signal from the other signals concurrently transmitted over the same frequency band.
  • the use of CDMA produces an increase in system traffic capacity, improves overall call quality and noise reduction, and provides a reliable transport mechanism for data service traffic.
  • CDMA digital systems In CDMA digital systems, all BS transmissions are time synchronized based upon a common CDMA system time.
  • CDMA system time is referenced to the Greenwich Mean Time (GMT) time scale.
  • GTT Greenwich Mean Time
  • the CDMA system time is used to synchronize the timing of all network signals and operations. While mobile phones currently process signals that are encoded with the system time, currently this time is not presented to the user in any meaningful or usable manner.
  • a system or method using this time could inform the user of the current time, within the accuracy of the GMT time standard. Additionally, such a system or method could provide the user with a number of referenced time choices, for example time referenced to different time zones, to choose from. The user would then set their mobile phone to a local time in accordance with the time zone selected from the provided options. In systems where the mobile phone and the PDA are integrated into a single unit, this same system time could be used, for example, to update files, appointments, calendars, or other time specific data in the PDA.
  • an apparatus including a portable digital device.
  • the portable device is associated with a previous local time and adapted to receive a time-encoded signal transmitted across a cellular network, which represents a network system time.
  • the device receives the signal when the device is activated.
  • the apparatus also includes a deriving mechanism for deriving the system time from the received signal and a converter for converting the system time to a current local time.
  • the apparatus includes an updating mechanism for updating the previous local time to the current local time and a conveying mechanism for conveying the current local time to a user.
  • FIG. 1 is a chart illustrating a basic structure of a cellular network.
  • FIG. 2 illustrates a single cellular phone receiving transmission of a pilot signal from a BS.
  • FIG. 3 is an illustration of a typical mobile phone
  • FIG. 4 is an illustration of a PDA.
  • FIG. 5 illustrates a mobile phone and a PDA integrated into a single device and exemplary user modes.
  • FIG. 5B illustrates a block diagram of the integrated device of FIG. 5.
  • FIG. 6A is a flow chart of an embodiment an automatic mode of the present invention.
  • FIG. 6B is a flow chart of an embodiment of the data base update mode of the present invention.
  • FIG. 6C is a flow chart of an embodiment of the manual mode of operation.
  • FIG. 7 shows the integrated device of FIG. 4 displaying an appointment list.
  • FIG. 8 is an illustration of typical time zone options presented to a user.
  • FIG. 1 illustrates a typical cellular network configuration.
  • the phone when user 19 first activates his mobile phone, the phone transmits a series of signals, which serve to broadcast to the cellular network 1, a request to receive or transmit a call. Also transmitted is the mobile phone's identification and the location of the caller. The signal is received by each BS that is close enough to receive the signal, based upon the signal's strength.
  • the BS(s) 5, 7, 9 continuously transmit a beacon signal, referred to as a pilot signal, which serves to notify potential users that the system is available and ready for use.
  • a beacon signal referred to as a pilot signal
  • the mobile phone is allowed to receive and process the pilot signal from the nearest BS.
  • the mobile phone measures the signal strength of the incoming calls and, generally the BS transmitting the strongest signal is determined by the mobile phone to be the closest BS.
  • FIG. 2 depicts transmission of a pilot signal by a BS.
  • pilot signals 29 are transmitted from all of the BSs of a CDMA cellular system and are identical to one another except for the phase of the signal.
  • a portion of the information contained in the pilot signal 29 is the CDMA system time 29a.
  • the CDMA system time 29a is based upon the GMT time standard. Present cellular systems use this system time for system operation, billing, etc.
  • the use of CDMA system time is transparent to the user of an exemplary device, such as device 23.
  • FIGs. 3 and 4 illustrate a typical mobile phone 23 and PDA 25, respectively.
  • a user of a PDA device does not have access to an external time source.
  • the PDA 25 has an internal clock which is set by the user and does not change unless modified by the user.
  • the PDA 25 may contain information such as calendars and schedules which are time dependent and must be manually updated by the user.
  • More recent devices, such as the device 27 of FIG. 5, integrate both the mobile phone 23 and the PDA 25 into a single unit, such as, for example, the Qualcomm Corporation's pdQ series.
  • the integrated device 27 of FIG. 5 includes a PDA portion 27a and a mobile phone portion 27b.
  • This integrated device 27 may provide a user with the benefit of automatic real-time time displays based upon CDMA, or other similar system wide time scales, in order to facilitate seamless functionality between mobile 23 phone and the PDA device 25.
  • FIG. 5 also illustrates several exemplary modes of operations of integrated device 27.
  • FIG. 5B illustrates a block diagram of the integrated device 27.
  • FIG. 6A depicts an exemplary embodiment of the present invention implemented in an automatic operational mode 28c of integrated device 27, as shown in FIG. 5.
  • a user of integrated device 27 must first activate the device.
  • pilot signal 29 may be received, as indicated in block B40a, by a processor of the mobile phone (not shown).
  • the system time is derived using a deriving mechanism 27c and as indicated in block B40b. Because additional information is encoded in the pilot signal, the system time may be derived by extracting and separating the time information from the other informational components of the signal.
  • a converter 27d converts the system time to a local time as indicated in block B40c.
  • the local time includes the system time converted to the use r's correct local time, i.e. the user's local time zone 40c. This conversion is done in accordance with the GMT reference time and using a time zone offset. For example, for a user in Illinois, the CDMA system time 29a is 6 hours behind GMT, see e.g. 31 of FIG. 8. Similarly, a user in Australia is 11 hours ahead of GMT. Thus, in order for the system to convey the correct local time, the CDMA system time 29a is converted to the local time zone by using these previously mentioned offsets.
  • local time is conveyed to the user in block B40e via a conveying mechanism 27i.
  • the conveying of local time may include, for example, displaying the local time at a fixed portion of the user interface display of the integrated device 27.
  • the automatic mode of operation 28c of the integrated device 27 terminates in block B40i.
  • FIG. 6B describes a database mode of operation 28e of integrated device 27, as shown in FIG. 5.
  • This mode provides the user with an ability to manage the data stored in the PDA portion 27a of the integrated device 27.
  • This feature is important because the user may have time dependant information 25b, such as appointments, and /or calendars (shown in FIG. 7), stored in the PDA portion 27a of the integrated device 27.
  • blocks B42a, B42b, and B42c are similar to blocks
  • a comparator 27e compares a previous system time, stored in a memory block B42h, with a previous time, as indicated by block B42d. This previous time is updated, using an updating mechanism 27f to the current local time if the comparison of block B42d indicates that the previous time is different from the current local time of block B42e. This comparison is necessary because the user may have traveled to a time zone different than the zone the user was in the last time the phone was activated. The user may have thus entered time sensitive data into the PDA portion of the integrated device 27a which may be incorrect in the new time zone. As such, the comparison in block B42d determines whether or not the previous time is different from the current local time.
  • the database mode of operation terminates in block B42i. If the previous time and the current local time are different, an alerting mechanism 27g alerts the user in block B42f. Once the user has been alerted, the user has the option of activating and associating mechanism 27h to associate/update the time-dependent information, of memory block B42h, to the current time, as indicated in block B42g.
  • a number of different mode combinations can be produced from the database update feature, such as an automatic data update without notifying the user, or the complete de-selection of this feature entirely, as indicated in 28f . During de-selection, the time sensitive data is not updated.
  • the local time may be conveyed to in a manner similar to automatic operational mode's block B40e.
  • FIG. 6C describes a manual mode of operation of the integrated device 27.
  • the manual mode permits a user to select, using a selector 27k, any desired time and have that time conveyed as the system time of the integrated device 27.
  • the user for example, may set the integrated device 27 time 5 minutes ahead of the system time or to any other desired setting. In this mode, the CDMA system time 29a is not used.
  • the user When activating the manual mode, the user activates the device in block B44a and selects the manual mode of operation as indicated in block B44b, selected for example, by choosing the manual mode of operation 28d, as indicated in FIG. 5.
  • This selection would permit a presenting mechanism 27j to present the user with the list of time zone options 31, from which the user would merely select one of the time zones in block B44c.
  • an entry mechanism With a desired time zone selected, an entry mechanism would permit the user to enter the desired time in block B44d.
  • the conveying mechanism 27i would convey the desired time to the user in block B44e and the process ends at block B44f.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Human Computer Interaction (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Mobile Radio Communication Systems (AREA)
EP00988233A 1999-12-21 2000-12-20 Time synchronization in a cellular network device Withdrawn EP1240769A2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US46972099A 1999-12-21 1999-12-21
US469720 1999-12-21
PCT/US2000/034772 WO2001047220A2 (en) 1999-12-21 2000-12-20 Time synchronization in a cellular network device

Publications (1)

Publication Number Publication Date
EP1240769A2 true EP1240769A2 (en) 2002-09-18

Family

ID=34140755

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00988233A Withdrawn EP1240769A2 (en) 1999-12-21 2000-12-20 Time synchronization in a cellular network device

Country Status (6)

Country Link
EP (1) EP1240769A2 (ko)
JP (1) JP2004501523A (ko)
KR (1) KR20020065586A (ko)
CN (1) CN1460354A (ko)
AU (1) AU2446201A (ko)
WO (1) WO2001047220A2 (ko)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10979279B2 (en) 2014-07-03 2021-04-13 International Business Machines Corporation Clock synchronization in cloud computing

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DE10150847B4 (de) * 2001-10-15 2006-06-01 Siemens Ag Einfache und sichere Methode zum Ermitteln der Zeitzone eines Internet Clients
US7813311B2 (en) 2002-02-05 2010-10-12 Interdigital Technology Corporation Method and apparatus for synchronizing base stations
KR100504835B1 (ko) 2003-05-15 2005-07-29 엘지전자 주식회사 이동 통신 단말기의 지역시간 보정 방법
CN101056141B (zh) * 2007-05-28 2011-09-21 中兴通讯股份有限公司 一种在终端跨越时区时实时更新cdma网络时间的方法
KR100973854B1 (ko) * 2008-01-12 2010-08-03 신창욱 직부등의 전원연결구 조립구조
US7966410B2 (en) * 2008-09-25 2011-06-21 Microsoft Corporation Coordinating data delivery using time suggestions
CN101997714A (zh) * 2009-08-27 2011-03-30 华为技术有限公司 时间处理方法、装置和系统
KR101650747B1 (ko) * 2010-05-04 2016-08-24 삼성전자 주식회사 듀얼모드 단말기의 데이터 통신 시스템 스캔 방법 및 장치

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JP3005266B2 (ja) * 1990-09-07 2000-01-31 日本電気株式会社 自動車電話装置
CA2187063A1 (en) * 1996-10-03 1998-04-03 Roger John La Salle Synchronization of a timepiece to a reference time
GB2347313A (en) * 1999-02-22 2000-08-30 Nokia Mobile Phones Ltd Mobile telephone having means for displaying local time

Non-Patent Citations (1)

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See references of WO0147220A2 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10979279B2 (en) 2014-07-03 2021-04-13 International Business Machines Corporation Clock synchronization in cloud computing

Also Published As

Publication number Publication date
AU2446201A (en) 2001-07-03
WO2001047220A2 (en) 2001-06-28
JP2004501523A (ja) 2004-01-15
KR20020065586A (ko) 2002-08-13
WO2001047220A3 (en) 2002-01-17
CN1460354A (zh) 2003-12-03

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