+

WO2001063953A1 - Procede de realisation d'un transfert avec coupure dans un systeme de telephonie mobile - Google Patents

Procede de realisation d'un transfert avec coupure dans un systeme de telephonie mobile Download PDF

Info

Publication number
WO2001063953A1
WO2001063953A1 PCT/DE2001/000712 DE0100712W WO0163953A1 WO 2001063953 A1 WO2001063953 A1 WO 2001063953A1 DE 0100712 W DE0100712 W DE 0100712W WO 0163953 A1 WO0163953 A1 WO 0163953A1
Authority
WO
WIPO (PCT)
Prior art keywords
base station
mobile station
frame
transmitted
time
Prior art date
Application number
PCT/DE2001/000712
Other languages
German (de)
English (en)
Inventor
Bernhard Raaf
Christian Senninger
Original Assignee
Siemens Aktiengesellschaft
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 Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Priority to EP01925297A priority Critical patent/EP1258164A1/fr
Publication of WO2001063953A1 publication Critical patent/WO2001063953A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/0085—Hand-off measurements
    • H04W36/0094—Definition of hand-off measurement parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/06—Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information

Definitions

  • the present invention relates to a method for performing a hard handover process in a mobile radio system according to the preamble of claim 1.
  • the handover is a very time-critical process in mobile radio systems, since the continuity of the current connection must be guaranteed.
  • FIG. 5 two base stations BS1 and BS2 are shown as an example, between which a handover process is to be carried out, it being assumed below that a subscriber with a mobile station MS is away from a radio cell for which the mobile station BSl is responsible, m a radio cell for which the mobile station BS2 is responsible moves.
  • the switching of the connection between the base station BS1 and the mobile station MS to the base station BS2 is controlled by a switching center SC ('Switchmg Center').
  • SC switching center
  • the uplink transmission directions (from the mobile station to the corresponding base station) and the downlink transmission directions (from the corresponding base station to the mobile station) are shown in FIG. 5.
  • a connection to the new base station is established at the same time as the existing connection with the currently responsible base station. For the example shown in FIG. 5, this means that the same information is sent to the mobile station MS during this period of time via the base stations BS1 and BS2.
  • the mobile station MS again receives signals from both base stations BS1 and BS2 this time and can use both signals. If the signal of the new base station BS2 is completely received by the mobile station MS, the switching center SC can abandon the old base station BS1 and switch completely to the new base station BS2, as a result of which the soft handover process is completed.
  • HHO hard handover
  • a problem associated with a hard handover is the fact that the hard switchover from the currently responsible base station to a new base station usually results in data losses during real-time data transmission, for example in the transmission of voice data result in a brief interruption in the received and sent voice information.
  • FIG. 7 shows a representation of a hard handover process from the base station BS1 shown in FIG. 5 to the base station BS2, in particular the time sequence of the respective uplink and downlink connections between the respectively active base station and frames m or m + 1 transmitted to the mobile station are shown at the time of the hard handover.
  • the frequency synthesizer would have to remain on the frequency pair of the uplink and downlink of the old base station BS1 until the entire frame no. M has been sent to the base station BS1 via the uplink. Only then can the frequency synthesizer switch to the corresponding uplink / downlink frequency pair of the new base station BS2. However, this has the consequence that the frame number m + 1 sent via the downlink of the new base station BS2 cannot be received from the beginning by the mobile station MS, so that the entire content of this frame may be lost. Should the mobile station receive the downlink of the new base station BS2 as shown in FIG. 7, the mobile station can completely receive the uplink frame no.
  • the present invention is therefore based on the object of proposing a method for carrying out a hard handover process in a mobile radio system, it being possible for data losses during the hard handover process to be avoided or at least significantly reduced.
  • a hard handover process between the mobile station and the old base station which is responsible for communication with the mobile station before the hard handover, and / or between the mobile station and the new base station, which after the hard handover should be responsible for the communication with the mobile station, transmit a frame in the so-called 'compressed mode'.
  • both a frame between the mobile station and the old base station and a frame between the mobile station and the new base station are transmitted in the 'compressed mode' at the time of the hard handover process.
  • the 'Compressed Mode' which is applied in particular to both the downlink and the uplink, creates a transmission gap in the respectively compressed frame, which can be used for the hard handover.
  • the required frequency switching can be carried out during this transmission gap in the case of an intermediate frequency handover.
  • the transmission / reception power can be set with respect to the new base station and the required chip synchronization can be carried out during the transmission gaps.
  • processing for example decoding
  • the handover procedure is shortened and it can be especially with a best frame synchronism between the old base station and the new base station, data losses during the hard handover process can be avoided.
  • the mobile station can use a pilot bit sequence continuously transmitted by the new base station, in particular in the case of UMTS the CPICH channel ('Common Pilot Channel'), for synchronization to the downlink the new base station.
  • a pilot bit sequence continuously transmitted by the new base station in particular in the case of UMTS the CPICH channel ('Common Pilot Channel'), for synchronization to the downlink the new base station.
  • the mobile station use a transmission gap specially provided for this purpose during the transmission gap caused by the compressed mode
  • Uplmk synchronization signal is sent, which can then be evaluated for Uplmk synchronization by the new base station.
  • This uplmk synchronization signal can in particular be the PRACH preamble originally intended for the RACH channel ('Random Access Channel')
  • a complete control channel ('Dedicated Physical Control Channel 1 , DPCCH) to be transmitted during the transmission gap both from the mobile station and from the new base station during the transmission gap, which in particular contains power setting information (TPC bits,' Transmit Power Control ') for the respective receiver, so that not only the synchronization can be brought about, but also the transmission power of the mobile station and the new base station can be optimized before the actual data transmission between the mobile station and the new base station begins.
  • DPCCH 'Dedicated Physical Control Channel 1 , DPCCH
  • F g. 5 shows a simplified block diagram of a mobile radio system according to the invention
  • FIG. 7 shows a representation to explain the implementation of a hard handover process according to the prior art
  • the present invention is explained below using a mobile radio system in accordance with the so-called UMTS mobile radio standard ('Universal Mobile Telecommunication System').
  • UMTS mobile radio standard 'Universal Mobile Telecommunication System'
  • the invention is generally applicable to mobile radio systems in which a compression mode or 'compressed mode' described in more detail below is provided.
  • the transmitter of the mobile radio system is occasionally operated in a mode referred to as 'slotted mode' or 'compressed mode', in which case the information to be transmitted is transmitted to a receiver within certain frames in a compressed form are transmitted in order to obtain a blanking interval with one or more so-called 'idle slots' in the corresponding compressed frame, the Blanking interval of information bits is free.
  • the information must be transmitted in a shortened time interval.
  • each frame comprises 15 time slots and has a frame duration of 10 ms.
  • the 'compressed mode' is used, ie the information is transmitted in this frame in a compressed form, so that a transmission blanking interval ('idle period' or 'idle time') with several 'idle slots 1' occurs where no information is transmitted.
  • the transmission power can be increased during this frame operated in the 'compressed mode' in order to achieve a transmission quality which is not impaired by the 'compressed mode'.
  • the compressed frames can occur periodically or as a result of a command initiated by the mobile radio network.
  • the 15 tent slots of a frame can be compressed into up to eight time slots, while the mobile station neither transmits ('Uplink Compressed Mode') nor receives in the resulting blanking interval or 'Idle Time' of the remaining seven time slots (' Downlink Compressed Mode ').
  • the 'Compressed Mode' allows time during a hard handover process for the frequency switching ('Frequency Switchmg') or deco dation of the received frame etc. can be obtained without losing the data transmitted in the uplink and downlink.
  • the 'idle time' can be used for synchronization purposes or for power management, ie for setting the transmit and receive power.
  • FIG. 1 therefore corresponds fundamentally to that of FIG. 7, so that only the differences that are essential for the present invention are discussed below.
  • the base station BS1 responsible before the hard handover sends and receives the last frame no. M in the 'compressed mode'.
  • the blocks shown in Fig. 1 each symbolize the compressed frames.
  • the first time slot of the transmission gap ('Transmission Gap', TG) should be the ninth time slot (ie time slot No. 8) and the length of the transmission gap ('Transmission Gap Length', TGL) comprise seven time slots.
  • the base station BS2, which is to be switched to, also transmits and receives the first frame no.
  • 1024 chips 34816 chips in order to switch from the old base station BS1 to the new base station BS2, one chip corresponding to a time period of approximately 0.26 ⁇ s.
  • the uplink is sent by the mobile station MS with a time delay of 1024 chips to the received downlink.
  • the remaining time of 34816 chips will be a little shorter in reality if inaccuracies in the measurement of the difference in time ('Observed Time Difference Of Ar ⁇ val', OTDOA) and the time discretization when transmitting to the respective base station are taken into account.
  • the duration of the approximately 30,000 chips 7.8 ms' idle time 'can be used as a frequency switchover time in the case of a handover between base stations operating at different frequencies (' Inter Frequency Handover). Furthermore, this idle time 1 can be used for power settings, for chip synchronization and / or for processing, ms-specific decoding, the received frame, etc.
  • transmission gaps with different lengths can also be used for the individual frame, so that correspondingly different values result for the time available for the measures described above. Furthermore, it is sufficient if only either between a compressed frame is transmitted to the old base station BS1 and the mobile station MS or between the new base station BS2 and the mobile station.
  • FIG. 1 two points in time t1 and t2 are shown in FIG. 1, the switchover or handover process at point in time tl (ie with the first time slot of the transmission gap from the mobile station MS to the old base station BS1.
  • th compressed uplink frame no. m begins and is completed at time t2 (ie with the last time slot of the transmission gap of the compressed downlink frame no. m + 1 sent from the new base station BS2 to the mobile station MS).
  • each base station continuously transmits the so-called 'Common Pilot Channel' (CPICH), which contains so-called pilot bits for synchronization purposes.
  • CPICH 'Common Pilot Channel'
  • the timing of the uplink received from the base station BS2 had to be known approximately.
  • this uplink synchronization signal should have good correlation properties.
  • the RACH preamble actually intended for the 'Random Access Channel' could be sent by the mobile station MS as an uplink synchronization signal, for example (possibly repeated).
  • the distribution of the time slots used for this by the mobile station MS is chosen only as an example in FIG. 2.
  • RACH bursts are usually sent from a mobile station to a base station in order to establish a connection with it. These RACH bursts contain a predefined bit sequence which is very well suited for synchronization purposes and thus also for the required upmk synchronization.
  • the mobile station MS can also send other suitable pilot signals as an upmk synchronization signal.
  • a complete control channel ('dedicated physical control channel') is proposed between the mobile station MS and the new base station BS2 both via the uplink and via the downlink ', DPCCH).
  • a complete control channel ('dedicated physical control channel') is proposed between the mobile station MS and the new base station BS2 both via the uplink and via the downlink ', DPCCH).
  • a synchronization between the base station BS2 and the mobile station MS but also an optimization of the reception and transmission power can be achieved by means of a corresponding power control ('Open Loop Power Control')
  • the transmission power of the mobile station in particular via the control channel MS and base station BS2 is set to an optimal value before the actual data transmission begins.
  • the DPCCH control channel sent during the transmission gap from the mobile station MS or the base station BS2 should only contain so-called TPC bits and pilot bits.
  • the TPC bits ('Transmit Power Control'), the value of which is determined by the respective transmitter of the TPC bits after an evaluation of a received signal, contain an instruction for the respective receiver of the TPC bits to adjust their transmission power to the respective TPC Value corresponding to bits.
  • the TFCI bits ('Transport Format Combination Indicator') that are usually included with the DPCCH control channel in UMTS are not required.
  • FBI bits can be used to signal the necessary parameters when using different antennas with several adjustable operating modes ('Transmit Antenna Diversity').
  • the DPCCH control channel can, for example, be structured in the uplink in such a way that eight pilot bits and two TPC bits are transmitted per time slot.
  • a format should be selected for the downlink in which as little data as possible (in particular no TFCI bits) is transmitted so that as many pilot bits as possible are available.
  • Fields of the first time slot or the first time slots of the uplink and downlmk DPCCH can be pre-assigned with a fixed known bit pattern in order to support the synchronization procedure at the beginning. These TPC fields are then not used for power control. Only the TPC bits received during the subsequent time slots are then evaluated as commands for an increase or decrease in the transmission power.
  • the base station BS2 first transmits the DPCCH control channel during the transmission gap. After the mobile station MS has received the downlmk control channel, it sends 1024 chips later via the uplink also a DPCCH control channel, which then serves the base station BS2 for synchronization.
  • the time slots of the downlink and uplink occupied by a DPCCH control channel are each shown in dotted lines in FIG. 3.
  • the invention achieves the maximum advantage if both the old base station BS1 and the new base station BS2 transmit in such a time-related manner that - as shown in FIGS. 1 to 3 - the downlink of the old one from the mobile station MS
  • Base station BS1 is received frame-synchronously to the downlink of the new base station BS2, i.e. the compressed frame no. m + 1 of the base station BS2 from the mobile station MS immediately after the compressed frame NR. m is received at the base station BSl.
  • this frame synchronization is not absolutely necessary.
  • the 'Compressed Mode' can be used to achieve a seamless transition between the communication information m sent to frame no. M and frame no. M + 1.
  • the frame relation shown as 'Case 2' data loss will occur despite the use of 'Compressed Mode'. That if the frames are not synchronized with each other, the probability of data loss is reduced by using the 'Compressed Mode', although data loss cannot be completely avoided.
  • the signals of the two base stations BS1 and BS2, between which the handover is to be carried out are adapted in such a way that the frame numbers m and m + 1 are at least approximately synchronized.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente invention concerne un système de téléphonie mobile, en particulier un système de téléphonie mobile universel. Dans ce système, la trame (m+1), transmise au moment d'un transfert avec coupure entre une station mobile (MS) et une première station de base (BS1) momentanément responsable de la communication avec la station mobile (MS) et/ou la trame transmise entre la station mobile (MS) et une station de base (BS2) dorénavant responsable de la communication avec la station mobile (MS), sont transmises en mode compressé, afin de combler les lacunes de transmission apparaissant en mode compressé lors de la réalisation du transfert avec coupure.
PCT/DE2001/000712 2000-02-24 2001-02-23 Procede de realisation d'un transfert avec coupure dans un systeme de telephonie mobile WO2001063953A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP01925297A EP1258164A1 (fr) 2000-02-24 2001-02-23 Procede de realisation d'un transfert avec coupure dans un systeme de telephonie mobile

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10008614 2000-02-24
DE10008614.4 2000-02-24

Publications (1)

Publication Number Publication Date
WO2001063953A1 true WO2001063953A1 (fr) 2001-08-30

Family

ID=7632213

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2001/000712 WO2001063953A1 (fr) 2000-02-24 2001-02-23 Procede de realisation d'un transfert avec coupure dans un systeme de telephonie mobile

Country Status (2)

Country Link
EP (1) EP1258164A1 (fr)
WO (1) WO2001063953A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2832898A1 (fr) * 2001-11-28 2003-05-30 Wavecom Sa Procede de synchronisation dans un reseau cellulaire de telecommunication, procede de transfert intercellulaire, terminal et station de base correspondants
WO2003017688A3 (fr) * 2001-08-20 2004-05-27 Ericsson Telefon Ab L M Delai de transition d'etat et couts de signalisation reduits pour transitions d'etat de stations mobiles
US7792303B2 (en) 2004-07-14 2010-09-07 Intel Corporation Method of delivering direct proof private keys to devices using a distribution CD

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5533014A (en) * 1993-06-14 1996-07-02 Telefonaktiebolaget Lm Ericsson Non-continuous transmission for seamless handover in DS-CDMA systems
WO1997040592A1 (fr) * 1996-04-23 1997-10-30 Telefonaktiebolaget Lm Ericsson (Publ) Systemes en mode amcr-sd a compression multi-codee, et procedes associes

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5533014A (en) * 1993-06-14 1996-07-02 Telefonaktiebolaget Lm Ericsson Non-continuous transmission for seamless handover in DS-CDMA systems
WO1997040592A1 (fr) * 1996-04-23 1997-10-30 Telefonaktiebolaget Lm Ericsson (Publ) Systemes en mode amcr-sd a compression multi-codee, et procedes associes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GUSTAFSSON M ET AL: "Compressed Mode Techniques for Inter-Frequency Measurements in a Wide-band DS-CDMA System", 1 September 1997, WAVES OF THE YEAR 2000+ PIMRC. THE IEEE INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS. TECHNICAL PROGRAM,XX,XX, VOL. 1, PAGE(S) 231-235, XP002127494 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003017688A3 (fr) * 2001-08-20 2004-05-27 Ericsson Telefon Ab L M Delai de transition d'etat et couts de signalisation reduits pour transitions d'etat de stations mobiles
FR2832898A1 (fr) * 2001-11-28 2003-05-30 Wavecom Sa Procede de synchronisation dans un reseau cellulaire de telecommunication, procede de transfert intercellulaire, terminal et station de base correspondants
WO2003047128A1 (fr) 2001-11-28 2003-06-05 Wavecom Prcede de synchronisation dans un réseau cellulaire de télécommunication, procédé de transfert intercellulaire, terminal et station de base correspondants.
CN100426699C (zh) * 2001-11-28 2008-10-15 维夫康姆公司 蜂窝通信网络中的同步方法,切换方法及相应的终端和基站
US7466683B2 (en) 2001-11-28 2008-12-16 Wavecom Synchronization method in a cellular telecommunication network, hand-over method, corresponding terminal and base station
US7792303B2 (en) 2004-07-14 2010-09-07 Intel Corporation Method of delivering direct proof private keys to devices using a distribution CD

Also Published As

Publication number Publication date
EP1258164A1 (fr) 2002-11-20

Similar Documents

Publication Publication Date Title
DE69431287T2 (de) Übertragungszeitjustierung in der abwärtsverbindung eines systems mit kodemultiplex-vielfachzugriff
DE69318667T2 (de) Verfahren zur Übertragung einer Zeitverschiebungsnachricht an ein Fahrzeug das sich in einem zellularen Funkfernsprechnetz bewegt sowie Fahrzeug, Steuerungsvorrichtung, und Nachrichtenaustauschanordnung die dieses Verfahren verwenden
EP1125463B1 (fr) Procede d'adaptation des phases d'interruption necessaires pour la surveillance de canaux
DE69735320T2 (de) Sendeleistungssteuerung für die Abwärtsrichtung eines Mobilkommunikationssystems mit Site-Diversität
DE69533788T2 (de) Sanftes überreichungsschema für zellulares mobiles funkkommunikationssystem
DE69831358T2 (de) System und verfahren zur vereinfachung des weiterreichens
DE69730265T2 (de) Verfahren und Gerät zur Steuerung der Rufweiterreichung in einer Satellitentelekommunikationsanordnung
DE69418547T2 (de) Verfahren und gerät zum weiterreichen einer mobilen station von einem ersten zu einem zweiten kanal in einer mobilen funkübertragungsanordnung
DE69602078T2 (de) Kommunikationssystem und verfahren dafür
DE69728745T2 (de) Signal-übertragungsverfahren, mobiles endgerät, und basisstationsgerät für mobiles cdma kommunikationssystem
DE69926297T2 (de) Verfahren zum Weiterreichen zwischen zwei Relays einer Zelle eines digitalen zellularen Funkkommunikationssystems mittels eines gemeinsamen Übergangskanals.
DE60038021T2 (de) Vorrichtung und verfahren zur geschalteten übertragung in einem cdma-kommunikationssystem
EP1118175B1 (fr) Procede pour faire fonctionner sans perturbation au moins deux stations de base
DE69634836T2 (de) Überwachungsverfahren für basisstationen mit diskontinuierlichen steuerkanalaussendungen
EP1138172B1 (fr) Procede pour reduire les phases d'interruption necessaires pour la surveillance de canaux voisins
DE60107956T2 (de) Verfahren zur Beobachtung von Signalen zwischen Kommunikationssystemen, die entsprechend unterschiedlicher Zeitraster operieren
DE602005000166T2 (de) Wahl von Basisstations-Antennen für ein "synchronized set" und ein "active set"
EP1393473B1 (fr) Procede permettant de synchroniser des stations de base dans un systeme de radiocommunication
DE69923314T2 (de) Geschwindigkeitsabhängiges soft handover für ein zellulares cdma-system mit zufälliger auswahl der basisstation
CH693807A5 (de) Verfahren zum Festlegen der Sendeleistung einer Mobilstation sowie Mobilstation zur Durchführung eines solchen Verfahrens.
EP0954122A1 (fr) Méthode pour la gestion d'un système de communication radio et tel système
DE60133243T2 (de) Mobilkommunikationssystem und Verfahren, Mobilstationen und Basisstationen für ein derartiges System
DE69723712T2 (de) Dual-mode tragbares telefongerät
EP1125462B1 (fr) Procede d'optimisation des phases d'interruption necessaires pour la surveillance de canaux
DE19957299B4 (de) Verfahren zur Sendeleistungsregelung in einem Funk-Kommunikationssystem

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CN HU US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2001925297

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2001925297

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 2001925297

Country of ref document: EP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载