WO2005117311A1 - Procede et systeme de synchronisation distribuee - Google Patents
Procede et systeme de synchronisation distribuee Download PDFInfo
- Publication number
- WO2005117311A1 WO2005117311A1 PCT/EP2005/052056 EP2005052056W WO2005117311A1 WO 2005117311 A1 WO2005117311 A1 WO 2005117311A1 EP 2005052056 W EP2005052056 W EP 2005052056W WO 2005117311 A1 WO2005117311 A1 WO 2005117311A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- time
- station
- network
- stations
- synchronization
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
- H04J3/0661—Clock or time synchronisation among packet nodes using timestamps
- H04J3/0664—Clock or time synchronisation among packet nodes using timestamps unidirectional timestamps
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/001—Synchronization between nodes
- H04W56/002—Mutual synchronization
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
- H04J3/0661—Clock or time synchronisation among packet nodes using timestamps
- H04J3/0667—Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays
Definitions
- the invention relates to a method and a system for distributed synchronization. It applies for example in ad Hoc networks. It is also used in wireless networks of the Large Scale Wireless Network type with access or transmission requiring global synchronization. It applies to radio networks.
- node or “station” designates any entity of the network, implemented in hardware or software which can be the entry point or the exit point (end) of an exchange or transmission of information between stations. .
- a station is for example chosen as a time reference or synchronization master.
- the other stations are gradually synchronized with respect to this reference station, by constructing a synchronization tree in a decentralized manner.
- the neighboring stations of the reference station synchronize on the latter, then on the stations located at two hops which synchronize by selecting a single-hop station as parent and so on.
- This method has a number of drawbacks in the context of mobile networks. In fact, if the network becomes fragmented, it becomes necessary to choose another reference station in the part not containing the reference station.
- the synchronization method and system use in particular the transmissions (exchanges) between the stations connected by mainly radio links.
- the process does not use a reference station or an external reference under normal operating conditions; synchronization can appear at any time (absence of a master).
- the invention relates in particular to a method of synchronization distributed in a communication network comprising several stations exchanging messages between them.
- the invention has in particular the following advantages: o
- the method does not require the explicit designation of one or more reference stations and it is completely distributed, that is to say based on local information, o II automatically supports mobile networks and the creation or destruction of links and is therefore from this point of view extremely robust, o II allows to take into account or not the correction of propagation times, o II allows to include stations having '' an accurate external reference such as stations equipped with an external reference time such as a GPS receiver, and in this case to align the network on this time, where it supports the fragmentation and fusion of the sub-networks which may be created due to the lack of connectivity between stations, and in this case favors in terms of capacity the parts where there is a station with an external reference time.
- FIG. 1 an example of architecture of the system according to the invention.
- Figure 2 an example of rough synchronization in an ad hoc network
- Figure 3 an example of fine synchronization in an ad hoc network
- Figure 4 an example of a system organized in clusters.
- FIG. 1 shows schematically a synchronization system according to the invention. The system is arranged at a station or an Ni node.
- An internal clock H whose time is controlled by a pilot and an optional delay control device (for example suppression of top pilot) in such a way that the time drift is always negative
- o A C_E / R device which receives messages and in particular has the function of measuring the reception time and controlling the time of transmission of messages.
- This device also receives information from the internal clock
- o A correction device Co for the hour H which is a function of the measurements of the arrival times and the times of transmission of the messages.
- This device receives the time information (T, ⁇ T) transported by the messages and calculates the synchronization data to be transported, o An optional external reference clock.
- Figure 2 shows schematically an example of an ad hoc network. It comprises several nodes or stations linked together by homogeneous or non-homogeneous communication links, respectively designated in the figure by solid or dotted trains. The nodes can be mobile or not and each have an internal clock. Clocks are assumed not to be initially synchronous and to drift over time. Communication links are, for example, radio links. All of these connections form, for example, a connected network.
- the method synchronizes the clocks of all the nodes through exchanges between a station (node) and the connected neighboring stations.
- the method assumes that the message exchanges between stations are carried out as follows: a station A which receives a transmission from station B determines the transmission time of B (measured in clock B) and the time to receive the message in his clock (clock A). This is done, for example, explicitly when the message sent by B contains its time of issue or another indicator. This can also be implicit when the message is transmitted synchronously with respect to an agreed frame or time. The instant of arrival of the message at station A can be measured by itself (A).
- the difference between the time of transmission and the time of reception is notably due to the difference between the hours of the clocks at the time of transmission, the drift during transmission and the propagation time.
- only the synchronization of the clocks, to the nearest propagation time is taken into account. This is commonly referred to as "rough synchronization".
- rough synchronization Even if the system is initially synchronized, in the absence of readjustment, the time of each station will drift and the network will desynchronize.
- a first policy is to readjust each message received. If there are many exchanges, the network can remain synchronized, but the system is unstable. The time on this network will slow down considerably and in an uncontrolled manner, due to the propagation time which delays the transmissions.
- each station of the network synchronizes itself for example on the emission of a station B, only if the received transmission is in advance; that is, if in station B the message is sent at T 0 (clock of B) it is received at T 0 -X (with X ⁇ 0) in the clock of A. This implies that l B's clock is ahead, since the propagation times can only delay the message.
- each station regularly transmits a message to its neighbors, the network remains synchronized, to the nearest propagation time, the precision depending only on the transmission rhythm of each station (on the drift of the clocks between transmissions).
- the network depends little or no on the stability of the links (insofar as the network remains globally connected) and on the order in which the messages are exchanged.
- the time of a network station cannot drift faster than the fastest of the network clocks and slower than the slowest.
- the clocks have a drift between + D and -D when they are isolated, the time drift of the network station will remain +/- D.
- the proposed time setting procedure will not cause them to drift.
- This characteristic of the proposed method is important, because it is necessary to be able to estimate the maximum drifts between isolated stations or parts of isolated networks, in order to be able to re-synchronize them as quickly as possible.
- the stations will naturally return to the network without any particular procedure.
- the steps described above at the station level apply to the group of stations level. If we have a set of networks, we will obtain a synchronization of this network by aligning network A on network B if the latter is ahead.
- Fine synchronization The process also offers the possibility of correcting the propagation times.
- This variant designated under the expression fine synchronization represented in FIG. 3, uses in particular a round-trip measurement to correct the propagation times between two stations.
- the fine synchronization links are represented in the figure by dotted lines.
- the method comprises for example the following conventional steps: the station A measures the arrival difference Ti of the messages with B as described above and B does the same by measuring the arrival difference T 2 with the messages of A. The stations exchange these deviations
- T 2 - ⁇ H + ⁇
- ⁇ H corresponds to the errors of the clocks in the stations and ⁇ to the propagation time between the two stations.
- the proposed method has in particular the following two characteristics: o It does not have any requirement of synchronism in the exchanges between the stations (except a sufficient rhythm compatible with the drift and the desired precision) o It makes it possible to limit the number of neighbors with which a station must synchronize in a fine manner, without imposing a strict diagram of this synchronization graph, which must simply maintain the connectivity of the network. For this each station has a table allowing to memorize the evolution of synchronizations (Table of corrections) made within the station.
- Ti is corrected (thanks to the table of corrections) for clock corrections made at station A since the time of reception T ° a and the instant of emission T'a of a new message from A to B, to obtain - corrections.
- the device Co of station B receiving at time Ta (time of reception of the new message), the values AT 01 , T '° a and Ta of the remote station A, corrects AT * of the corrections made between T' ° a and Ta, to obtain ⁇ T 3 and measure ⁇ T 2 T'a-Ta deviation between T'a and Ta. If ⁇ T 2 - ⁇ T 3 is greater than a value ⁇ ', with ⁇ ' tending towards zero for example, the device Co applies a correction, with ⁇ T 2 - ⁇ T measuring twice the advance of the distant station corrected for propagation times. The principle used is therefore in this sense similar to the rough synchronization described above, and each station adopts the most advanced time between them and its neighbors.
- FIG. 4 shows schematically an example of fine synchronization which applies to a hierarchical architecture. Fine synchronization (links shown in dotted lines in the figure) can be applied between cluster leaders
- radio silent stations that is to say stations capable of receiving but not transmitting.
- a station in radio silence adopts the time received from a neighboring station regardless of whether the station is early or late.
- the method limits synchronization only if the time received is not too late over the local time. This allows the station to stay synchronized on the most advanced network.
- the threshold is chosen for example according to the drift of the clocks and the propagation times of the system.
- stations with external reference time references We want a set of stations connected to each other, some of which have an external reference reference, for example stations which are synchronized on a GPS, to remain synchronized on this reference time and that all stations are also synchronized to this time. Apart from the reference time present in certain stations, all the stations are provided with an hour meter (internal time) maintained by a pilot who sends tops regularly for example.
- the process then includes the following steps:
- the stations have an internal time as before.
- a pilot maintains this clock with a certain precision of +/- A. This clock is readjusted each time a message is received by messages in advance and sometimes by round-trip measurements to correct the propagation times, as indicated above for fine synchronization. or coarse.
- the external reference time of the station appears as a particular readjustment message, and obeys the same criteria as a message from a neighboring station.
- the internal pilot is designed to cause a natural delay of the internal clock. Under these conditions, stations with a reference time will naturally be ahead of stations without one and the reference time will propagate in the network naturally without any signaling being necessary. If we imagine that the internal time is maintained on the tops of the internal pilot, the process removes for example a top from time to time so that the drift is, for example, 0 / -2A, instead of + A / - AT.
- the way to modify the emission of the tops depends for example on the structure of the pilot. This process is equally applicable for fine synchronization or coarse synchronization.
- the method according to the invention makes it possible to solve the problem of synchronization in parts of networks. It allows automatic maintenance of a common time despite changes in the topology of a network. It was previously indicated how the parts of networks having an external reference time, for example a GPS time, naturally synchronized with this time.
- the method according to the invention makes no assumption on the nature of the means of communication which link the stations. They can be homogeneous links in a frequency range, or different means, and the method makes it possible to obtain a precise common time. The only assumption is that the stations know how to communicate with each other.
- this time setting is often used to allow stations to communicate on a given means of communication, for example, the means of communication is a TDMA network (Time division multiple access) with frequency evasion or EVF.
- TDMA network Time division multiple access
- EVF frequency evasion or EVF.
- these communication systems have internal procedures to detect stations that are not synchronized with
- the method according to the invention makes it possible to limit the loss of capacity in networks having an external time reference and to concentrate it on those which do not have one.
- networks with external reference time will never have to synchronize.
- Resource consumption for this function will be limited to situations considered degraded or in the initialization phases.
- stations on the network must know that they do not have an external reference in the network. This requires a minimum of signaling and can cause significant delays, but the propagation time of this signaling is not critical, since it is not linked to the synchronization otherwise ensured by the proposed method.
- the situation is very different from a master station whose loss must be quickly detected on pain of loss of synchronization.
- Another aspect is that the method naturally provides a certain immunity to the synchronization replay.
- a replay is late and therefore, taking into account the method, cannot disturb the network where it is retransmitted. On a neighboring network, if the latter is ahead, it has no effect. If it is late the replay will cause the advance, but in fact will thus contribute to the synchronization of the system since the method searches for networks in advance.
- the method can also be implemented on an annex network which will serve to synchronize the main network.
- the transmission means may or may not request that the stations be synchronized in order to be able to carry out the exchanges.
- the method according to the invention allows the maintenance of this synchronization.
- the method is also applicable in the acquisition phase of the initial synchronization, a procedure specific to the transmission means used.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
- Mobile Radio Communication Systems (AREA)
- Small-Scale Networks (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
- Radio Relay Systems (AREA)
- Time-Division Multiplex Systems (AREA)
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007513903A JP2008501262A (ja) | 2004-05-28 | 2005-05-04 | 分散された同期方法及びシステム |
DE602005005816T DE602005005816T2 (de) | 2004-05-28 | 2005-05-04 | Verfahren und system zur verteilten synchronisation |
EP05743113A EP1756987B1 (fr) | 2004-05-28 | 2005-05-04 | Procede et systeme de synchronisation distribuee |
KR1020067024989A KR101152161B1 (ko) | 2004-05-28 | 2005-05-04 | 분산 동기화 방법 및 시스템 |
CA2568558A CA2568558C (fr) | 2004-05-28 | 2005-05-04 | Procede et systeme de synchronisation distribuee |
US11/569,663 US7860040B2 (en) | 2004-05-28 | 2005-05-04 | Distributed synchronization method and system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0405809A FR2871006B1 (fr) | 2004-05-28 | 2004-05-28 | Procede et systeme de synchronisation distribuee |
FR0405809 | 2004-05-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005117311A1 true WO2005117311A1 (fr) | 2005-12-08 |
Family
ID=34945023
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2005/052056 WO2005117311A1 (fr) | 2004-05-28 | 2005-05-04 | Procede et systeme de synchronisation distribuee |
Country Status (10)
Country | Link |
---|---|
US (1) | US7860040B2 (fr) |
EP (1) | EP1756987B1 (fr) |
JP (1) | JP2008501262A (fr) |
KR (1) | KR101152161B1 (fr) |
AT (1) | ATE391366T1 (fr) |
CA (1) | CA2568558C (fr) |
DE (1) | DE602005005816T2 (fr) |
ES (1) | ES2306147T3 (fr) |
FR (1) | FR2871006B1 (fr) |
WO (1) | WO2005117311A1 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010534431A (ja) * | 2007-07-20 | 2010-11-04 | ブルー ダニューブ ラブズ インク | 位相同期ローカルキャリアを有するマルチポイント信号発生の方法及びシステム |
CN105187149A (zh) * | 2015-09-28 | 2015-12-23 | 国电南瑞科技股份有限公司 | 基于卫星轨道自学习算法的时间同步系统自拟合输出系统及方法 |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4699250B2 (ja) * | 2006-03-20 | 2011-06-08 | 三菱電機株式会社 | 無線装置 |
US7843834B2 (en) * | 2006-09-15 | 2010-11-30 | Itron, Inc. | Use of minimal propagation delay path to optimize a mesh network |
KR20110102894A (ko) * | 2008-12-03 | 2011-09-19 | 노오텔 네트웍스 리미티드 | 다중 리던던트 gnss 동기화 시스템 |
JP5081874B2 (ja) * | 2009-08-03 | 2012-11-28 | 関西電力株式会社 | データ収集システム |
CN102469484B (zh) * | 2010-11-15 | 2015-02-04 | 中国移动通信集团公司 | 一种基站退服方法、一种基站以及一种时间服务器 |
KR101740937B1 (ko) * | 2011-12-15 | 2017-05-30 | 한국전자통신연구원 | 애드 혹 네트워크 시스템에서 분산 동기를 수행하는 방법 |
US8923464B2 (en) * | 2012-11-16 | 2014-12-30 | Qualcomm Incorporated | Methods and apparatus for enabling distributed frequency synchronization |
US9655072B2 (en) * | 2013-11-08 | 2017-05-16 | Qualcomm, Incorporated | Systems, apparatus and methods for synchronizing a global time reference for access points over the air |
US9921395B1 (en) | 2015-06-09 | 2018-03-20 | J.A. Woollam Co., Inc. | Beam focusing and beam collecting optics with wavelength dependent filter element adjustment of beam area |
US9442016B2 (en) | 2014-06-06 | 2016-09-13 | J.A. Woollam Co., Inc | Reflective focusing optics |
US10338362B1 (en) | 2014-06-06 | 2019-07-02 | J.A. Woollam Co., Inc. | Beam focusing and reflecting optics with enhanced detector system |
US10018815B1 (en) | 2014-06-06 | 2018-07-10 | J.A. Woolam Co., Inc. | Beam focusing and reflective optics |
DE102015121724A1 (de) * | 2015-12-14 | 2017-06-14 | Symeo Gmbh | System und Verfahren mit zumindest drei Signale empfangenden Stationen |
GB2554638B (en) * | 2016-09-28 | 2019-12-04 | Advanced Risc Mach Ltd | Error detection in communication networks |
CN108540354A (zh) * | 2017-03-02 | 2018-09-14 | 漳州立达信光电子科技有限公司 | 物联网终端装置与控制多个物联网装置的方法 |
CN111478834B (zh) * | 2020-03-25 | 2022-04-29 | 武汉迈信电气技术有限公司 | 一种基于非实时系统的EtherCAT主站同步方法 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20010022823A1 (en) * | 2000-03-20 | 2001-09-20 | Pierre Renaud | Method and system for multi-protocol clock recovery and generation |
US20040005902A1 (en) * | 2002-07-05 | 2004-01-08 | Belcea John M. | System and method for correcting the clock drift and maintaining the synchronization of low quality clocks in wireless networks |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6985750B1 (en) * | 1999-04-27 | 2006-01-10 | Bj Services Company | Wireless network system |
US7068746B1 (en) * | 2000-03-01 | 2006-06-27 | Lucent Technologies Inc. | Base station transceiver to radio network controller synchronization filtering function |
AU2002361767A1 (en) * | 2001-12-17 | 2003-07-09 | Becomm Corporation | Method and system for synchronization of content rendering |
EP1478131A1 (fr) * | 2003-05-12 | 2004-11-17 | Siemens Aktiengesellschaft | Procédé d'access alléatoire dans un réseau local |
US8149748B2 (en) * | 2006-11-14 | 2012-04-03 | Raytheon Company | Wireless data networking |
-
2004
- 2004-05-28 FR FR0405809A patent/FR2871006B1/fr not_active Expired - Lifetime
-
2005
- 2005-05-04 US US11/569,663 patent/US7860040B2/en not_active Expired - Fee Related
- 2005-05-04 WO PCT/EP2005/052056 patent/WO2005117311A1/fr active IP Right Grant
- 2005-05-04 DE DE602005005816T patent/DE602005005816T2/de active Active
- 2005-05-04 EP EP05743113A patent/EP1756987B1/fr not_active Not-in-force
- 2005-05-04 KR KR1020067024989A patent/KR101152161B1/ko not_active IP Right Cessation
- 2005-05-04 ES ES05743113T patent/ES2306147T3/es active Active
- 2005-05-04 AT AT05743113T patent/ATE391366T1/de not_active IP Right Cessation
- 2005-05-04 CA CA2568558A patent/CA2568558C/fr not_active Expired - Fee Related
- 2005-05-04 JP JP2007513903A patent/JP2008501262A/ja active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20010022823A1 (en) * | 2000-03-20 | 2001-09-20 | Pierre Renaud | Method and system for multi-protocol clock recovery and generation |
US20040005902A1 (en) * | 2002-07-05 | 2004-01-08 | Belcea John M. | System and method for correcting the clock drift and maintaining the synchronization of low quality clocks in wireless networks |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010534431A (ja) * | 2007-07-20 | 2010-11-04 | ブルー ダニューブ ラブズ インク | 位相同期ローカルキャリアを有するマルチポイント信号発生の方法及びシステム |
CN105187149A (zh) * | 2015-09-28 | 2015-12-23 | 国电南瑞科技股份有限公司 | 基于卫星轨道自学习算法的时间同步系统自拟合输出系统及方法 |
CN105187149B (zh) * | 2015-09-28 | 2017-08-04 | 国电南瑞科技股份有限公司 | 基于卫星轨道自学习算法的时间同步系统自拟合输出系统及方法 |
Also Published As
Publication number | Publication date |
---|---|
CA2568558A1 (fr) | 2005-12-08 |
ATE391366T1 (de) | 2008-04-15 |
CA2568558C (fr) | 2017-03-07 |
JP2008501262A (ja) | 2008-01-17 |
US20070230434A1 (en) | 2007-10-04 |
DE602005005816T2 (de) | 2009-04-16 |
EP1756987B1 (fr) | 2008-04-02 |
FR2871006B1 (fr) | 2008-09-12 |
FR2871006A1 (fr) | 2005-12-02 |
KR101152161B1 (ko) | 2012-06-15 |
ES2306147T3 (es) | 2008-11-01 |
KR20070022706A (ko) | 2007-02-27 |
US7860040B2 (en) | 2010-12-28 |
EP1756987A1 (fr) | 2007-02-28 |
DE602005005816D1 (de) | 2008-05-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1756987B1 (fr) | Procede et systeme de synchronisation distribuee | |
FR2807244A1 (fr) | Systeme de compensation de retard en boucle incorpore pour emetteur-recepteur a plusieurs canaux et procede associe | |
EP2149214B1 (fr) | Synchronisation en phase de noeuds dans un reseau de telecommunications | |
WO2020043181A1 (fr) | Procédé et appareil de synchronisation d'horloge, système, support de stockage, et dispositif électronique | |
US20110090925A1 (en) | Method for synchronization in networks | |
CN101765198B (zh) | 一种时钟同步的方法、装置和系统 | |
US8204035B2 (en) | Network node | |
EP2579062B1 (fr) | Système d'augmentation spatial adapté pour améliorer la précision et la fiabilité des données délivrées par un système de navigation par satellites, et procédé associé | |
FR2790888A1 (fr) | Procede de synchronisation entre une horloge de reference d'une station au sol et une horloge d'au moins un dispositif distant | |
EP3253139A1 (fr) | Méthode de synchronisation de noeuds dans un réseau de capteurs sans fil | |
CN113424466B (zh) | 时钟同步的方法和装置 | |
EP1875634B1 (fr) | Procede de synchronisation et d'asservissement dans les systemes de communications sans fil | |
FR3085570A1 (fr) | Procede et systeme de synchronisation | |
FR2658969A1 (fr) | Systeme constitue en reseau tel qu'un systeme radiotelephonique cellulaire, permettant de mesurer le retard de transmission entre nóoeuds du reseau et de les synchroniser entre eux. | |
US20030214936A1 (en) | Using GPS signals to synchronize stationary multiple master networks | |
EP2190131B1 (fr) | Procédé de gestion d'antennes pour un système de communication par onde radiofréquence de type dect et système correspondant | |
JP3538374B2 (ja) | 時刻供給システム及び時刻供給装置 | |
EP3487089A1 (fr) | Système de diffusion d'une référence temporelle dans un aéronef | |
CN110336635B (zh) | 一种时间噪声传递方法、装置和网络节点 | |
WO2016207428A1 (fr) | Procédé de détermination du décalage temporel existant entre les horloges des stations de base d'un réseau de communication | |
Chakrabarty et al. | Time Synchronization In Wireless Sensor Networks | |
FR2903846A1 (fr) | Detection de collision asynchrone dans un systeme de telephonie mobile directe. | |
FR3012709A1 (fr) | Procede et systeme de synchronisation horaire |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 11569663 Country of ref document: US Ref document number: 2007230434 Country of ref document: US Ref document number: 2007513903 Country of ref document: JP Ref document number: 2568558 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020067024989 Country of ref document: KR |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWW | Wipo information: withdrawn in national office |
Country of ref document: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2005743113 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1020067024989 Country of ref document: KR |
|
WWP | Wipo information: published in national office |
Ref document number: 2005743113 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 11569663 Country of ref document: US |
|
WWG | Wipo information: grant in national office |
Ref document number: 2005743113 Country of ref document: EP |