WO2000055991A1 - Procede de synchronisation de stations de base d'un systeme de transmission radio - Google Patents

Procede de synchronisation de stations de base d'un systeme de transmission radio Download PDF

Info

Publication number
WO2000055991A1
WO2000055991A1 PCT/DE2000/000785 DE0000785W WO0055991A1 WO 2000055991 A1 WO2000055991 A1 WO 2000055991A1 DE 0000785 W DE0000785 W DE 0000785W WO 0055991 A1 WO0055991 A1 WO 0055991A1
Authority
WO
WIPO (PCT)
Prior art keywords
synchronization
base station
ebs
synchronization sequence
base stations
Prior art date
Application number
PCT/DE2000/000785
Other languages
German (de)
English (en)
Inventor
Toplica Pacic
Markus Dillinger
Gerald Ostermayer
Jürgen Schindler
Peter Slanina
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
Publication of WO2000055991A1 publication Critical patent/WO2000055991A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/001—Synchronization between nodes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/0055—Synchronisation arrangements determining timing error of reception due to propagation delay
    • H04W56/0065—Synchronisation arrangements determining timing error of reception due to propagation delay using measurement of signal travel time
    • H04W56/007—Open loop measurement
    • H04W56/0075—Open loop measurement based on arrival time vs. expected arrival time
    • H04W56/0085—Open loop measurement based on arrival time vs. expected arrival time detecting a given structure in the signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W92/00—Interfaces specially adapted for wireless communication networks
    • H04W92/16—Interfaces between hierarchically similar devices
    • H04W92/20—Interfaces between hierarchically similar devices between access points

Definitions

  • the invention relates to a method and an arrangement for transmitting power control in a radio communication system, in particular in a mobile radio system.
  • radio communication systems information (for example voice, picture information or other data) is transmitted with the aid of electromagnetic waves via a radio interface.
  • the radio interface relates to a connection between a base station and subscriber stations, where the subscriber stations can be mobile stations or fixed radio stations.
  • the electromagnetic waves are emitted at carrier frequencies that lie in the frequency band provided for the respective system.
  • UMTS Universal Mobile Telecommunication System
  • 3rd generation systems frequencies in the frequency band of approx. 2000 MHz are provided.
  • Two modes are provided for the third mobile radio generation, one mode being FDD operation (frequency division duplex), see ETSI STC SMG2 UMTS-Ll, Tdoc SMG2 UMTS-Ll 221/98, dated August 25, 1998, and the other mode a TDD operation (time division duplex), see DE 198 27 700.
  • the operating modes are used in different frequency bands and each use time slots.
  • the invention has for its object to provide a method for the synchronization of base stations, the one decentralized and self-regulating synchronization with little effort. This object is achieved by the method having the features of claim 1. Advantageous developments of the invention can be found in the subclaims.
  • the inventive method according to the features of claim 1 advantageously allows synchronization of neighboring base stations of a radio communication system.
  • the base stations can in each case synchronize themselves by means of the base station synchronization sequences according to the invention transmitted by further base stations, as a result of which a homogeneous time base is created and interference interference is advantageously reduced.
  • no additional physical connections to the network and a hierarchical structure for synchronization are advantageously required.
  • the base station synchronization sequence can be integrated m the signaling of the known synchronization channel in a simple manner, whereby a low technical outlay is achieved.
  • the synchronization sequences are transmitted according to a further development of the invention in m time slots, in which information of a general organization channel is additionally transmitted. This means that only a small number of time slots in the downward direction have to be kept ready. The degree of freedom of the asymmetry of both transmission directions in the TDD mode is hardly restricted.
  • further information is advantageously transmitted by a choice of the synchronization sequences and / or their sequence.
  • the further information relates, for example, to a frame synchronization, middle messages used by the base station, spreading codes or general codes, or information on the configuration of the general organizational channel.
  • a high coding gain is achieved if the coding of the further information extends over several time slots due to the choice and / or sequence of the synchronization sequences.
  • the synchronization sequence and / or the base station synchronization sequence are unmodulated orthogonal gold codes. This means that the synchronization process can be used for both TDD and FDD mode. According to the invention, the interference of the synchronization channel on the other connections is reduced in the FDD mode.
  • the synchronization method is also suitable for radio communication systems in which the time slots are part of a TDD transmission scheme with broadband channels. Several time slots per frame can also be used for synchronization. For multimode subscriber stations, parts of the detection device can thus be used for both modes.
  • the accuracy of the synchronization is improved in accordance with further developments if the base station evaluates the base station synchronization sequences of as large a number of adjacent further base stations as possible. Since a base station is generally surrounded by a large number of further base stations, the synchronicity with all these base stations is thus established.
  • the synchronization is advantageously carried out on the basis of averaging reception times of the base station synchronization sequences of a plurality of base stations. This will relative shift in the transmission times of base stations in an area to a low tolerable value. With this averaging it can be provided that a different weighting of the reception times with regard to different base stations is taken into account. For example, a high reception level m usually means an adjacent base station at a short distance or with a particularly large store flow, so that synchronization is particularly important for the relationship with this base station. The weighting factor is therefore large for their signal.
  • the number of information elements of the base station synchronization sequence is chosen to be larger than the number of information elements of the synchronization sequence that are used to synchronize the subscriber stations.
  • the base station synchronization sequence is selected such that it has no correlation with the synchronization sequence for the synchronization of subscriber stations, since subscriber stations establishing a communication connection, for example, would otherwise have been synchronized to an incorrect time reference.
  • the base station synchronization sequence is multiplexed with the synchronization sequence, the time cycle corresponding to a further embodiment being larger than the time cycle the synchronization sequence is selected.
  • the multiplication advantageously reduces the signaling load, the base station synchronization sequence being transmitted, for example, only in every 50th to 100th time frame. This large periodicity is sufficient in comparison to the periodicity of the synchronization sequence that is sent in each time frame, since the synchronicity of the base stations changes during this period only by a maximum tolerable time offset. As a result, the service quality for the subscriber stations is advantageously only slightly deteriorated.
  • the periodicity of the base station synchronization sequence can be signaled, for example, in the general organization channel, so that a misinterpretation by the subscriber stations is also excluded.
  • the base stations of each base station can be assigned a different point in time, for example a respective time frame, or an individual base station synchronization sequence for each base station.
  • the individual base station synchronization sequences can be derived from a common base sequence in accordance with the known synchronization sequences, as a result of which good correlation behavior can be achieved.
  • the simultaneous transmission of the base station synchronization sequences advantageously enables the base station to be synchronized quickly.
  • An application of the method according to the invention is particularly advantageous in radio communication systems with TDD transmission methods if, for example, individual time slots of a frame for the up or down direction of different Ba- stations are used.
  • the base stations in the same frequency band can evaluate the transmissions from the other base stations with the existing receivers. No additional hardware is required.
  • a broadband frequency band is provided for the UMTS mobile radio system, signals transmitted simultaneously within the frequency band differing on the basis of a spreading code that is specific to the connection.
  • FIG. 1 shows a block diagram of a radio communication system, in particular a mobile radio system
  • FIG. 2 shows a schematic representation of an FDD radio interface between a base station and subscriber stations
  • FIG. 3 shows a schematic representation of a TDD radio interface
  • FIG. 4 shows an exemplary multiplexing of synchronization sequences 5 shows an exemplary structure of a synchronization channel.
  • the mobile radio system shown in FIG. 1 as an example of a radio communication system consists of a large number of mobile switching centers MSC which are networked with one another or which provide access to a fixed network PSTN. Furthermore, these mobile switching centers MSC are each connected to at least one device RNM for allocating radio resources. Each of these devices RNM in turn enables a connection to at least one base station BS. Such a base station BS can be Interface a connection to other radio stations, e.g.
  • At least one radio cell is formed by each base station BS. In the case of sectorization or hierarchical cell structures, several radio cells are also supplied per base station BS.
  • the OMC operations and maintenance center implements control and maintenance functions for the mobile radio system or for parts thereof. The functionality of this structure can be transferred to other radio communication systems to which the invention can be used, in particular for subscriber access networks with a wireless subscriber connection.
  • FIG. 2 schematically shows the radio transmission in FDD mode in the downward direction from the base station to the subscriber stations, with how m ETSI STC SMG2 UMTS-Ll, Tdoc SMG2 UMTS-Ll 221/98, from August 25, 1998, Fig. 9, a frame structure is assumed.
  • E superframe contains 72 frames frl, fr2, .. fr ⁇ , .. fr72, each individual frame comprising 16 time slots tsl, ts2, .., tsi, .., tsl 6.
  • Different channels SCH, DPCH, CCPCH are offered in parallel within a time slot tsi, the information of the channels SCH, DPCH, CCPCH differing in the spreading with individual spreading codes.
  • a first control channel CCPCH with a fixed data rate which contains a pilot sequence pilot consisting of 8 bits, which is followed by a data part data.
  • the pilot sequence pilot is used for channel estimation.
  • a physical channel DPCH assigned to a subscriber consists of a control channel DPCCH and a data channel DPDCH.
  • the former contains a pilot sequence pilot, information on the power control TPC and information on the service combination TFI.
  • the latter contains spread data.
  • a synchronization channel SCH synchronization sequences cp it are sent with a known signal form, which serve the subscriber stations as a reference for a time synchronization. With this FDD transmission method, the frequency bands for the upward direction and the downward direction are separated.
  • the frame structure of the radio transmission in TDD mode can be seen from FIG. 3.
  • a TDMA component ti e di-Vision multiple access
  • a division of a broadband frequency range is provided for a plurality of time slots ts of the same duration, for example 16 time slots tsO to tsl5, which form a time frame fr.
  • E frequency band extends over a frequency range B.
  • Some of the time slots are used in the downward direction DL and some of the time slots are used in the upward direction UL.
  • An asymmetry ratio of 3: 1 in favor of the downward direction DL is shown as an example.
  • the frequency band B for the upward direction UL corresponds to the frequency band B for the downward direction DL.
  • the same is repeated for other carrier frequencies.
  • the data d are spread individually for each connection with a fine structure, a spreading code c, so that, for example, n connections can be separated at the receiving end by this CDMA component (code division multiple access).
  • the spreading of individual symbols of the data d causes that within the symbol duration T Syrn Q
  • Chips of the duration T c ⁇ p are transmitted.
  • the Q chips form the connection-specific spreading code c.
  • the parameters of the radio interface used for both transmission modes are advantageously: Chip rate: 4,096 Mcps frame duration: 10 ms
  • Duration of a time slot 625 ⁇ s chips per time slot: 2560 spreading factor: variable Modulation type: QPSK
  • the document ETSI STC SMG2 UMTS-Ll, Tdoc SMG2 UMTS-Ll 221/98, dated August 25, 1998 two synchronization sequences cp, it is sent in each time slot ts of the FDD radio interface parts.
  • the first synchronization sequence cp consists of an unmodulated orthogonal gold code with a length of 256 chips and is transmitted in each time slot ts.
  • the first synchronization sequence cp is the same for all base stations BS and coincides with the start of the general organization channel BCCH.
  • the second synchronization sequence also consists of an unmodulated orthogonal gold code with a length of 256 chips.
  • the second synchronization sequence it is sent in parallel to the first synchronization sequence cp and can be re-selected from time slot to time slot.
  • the coding gain is large in number of possibilities, so that the synchronization sequences cp, for example, can also be sent with lower power.
  • the synchronization sequences cp, es are transmitted in the two time slots tsO, ts8 of the synchronization channel SCH, downward direction DL, for example a time separation of the synchronization sequences cp, es within the time slots ts economic use of radio resources is possible.
  • the described synchronization channel SCH is used for mutual synchronization of neighboring base stations BS1, BS2, BS3, as shown in FIG. 1 by way of example.
  • the base stations BS1, BS2, BS3 periodically send respective time slots ts, like the time slots tsO and ts8 according to FIG. 4 m, a base station synchronization sequence ebs.
  • This base station synchronization sequence ebs sent for example by the base station BS1, is received by the respectively adjacent further base stations BS2, BS3 and the time positions of the sequences ebs are evaluated.
  • the respective time position, possibly weighted with a weighting factor, of the base station synchronization sequence ebs is compared with one another, and the base station BS 'own synchronization is controlled in relation to the received sequences ebs.
  • each base station BS1, BS2, BS3 forms a radio cell.
  • the size of the radio cell is generally determined by the range of the general organization channel BCCH, which is transmitted by the base stations BS1, BS2, BS3, each with a maximum transmission power.
  • the base stations BS1 to BS3 are either the same
  • the radiation diagrams of the base stations BS1, BS2, BS3 and thus their radio cells thus overlap at least partially.
  • the arrangement of the base stations BS1, BS2, BS3 shown together with a division of the time slots ts between the three base stations BSl, BS2, BS3 leads to very high demands on the synchronization, since the transmissions from the base stations BS1 to BS3 do not occur at any location Radio cells should overlap unintentionally.
  • the synchronization of the neighboring base stations BS1, BS2, BS3 via the radio interface is carried out by constantly repeating sending, receiving, measuring and evaluating the time difference between the neighboring base stations involved until the time difference is eliminated by adapting the transmission times and synchronicity is achieved.
  • the number of chips in the base station synchronization sequence ebs is increased in comparison to the synchronization sequences cp, according to the invention.
  • the base station synchronization sequence ebs instead of a sequence of 256 chips, which consists of a combination of 16 existing gold code sequences with 16 chips each, the base station synchronization sequence ebs, for example, has a 2048 chip higher number of chips, corresponding to a factor of 8.
  • the base station synchronization sequence ebs can be formed in the same way as the synchronization sequences cp, using a gold code.
  • the extension of the sequence by a factor of 8 means an effective process gain when receiving the sequence m neighboring base station, so that the effective range of the
  • Base station synchronization sequence ebs is significantly increased. This process gain is approx. 10 odB compared to one
  • the base station synchronization sequences ebs of the respective base stations BS1, BS2, BS3 can be derived, for example, from a common base sequence, they must also have good mutual correlation properties, so that the base station BSl e enables simultaneous reception of all base station synchronization sequences ebs of the respectively adjacent further base stations BS2, BS3 becomes.
  • the choice of the base sequence and the base station synchronization sequences ebs derived therefrom can take place in such a way that a misinterpretation or confusion by a subscriber station MS with a synchronization sequence cp is prevented since this would lead to incorrect synchronization of the subscriber station MS.
  • the base station synchronization sequence ebs is time-multiplexed with the synchronization sequences cp, it for the synchronization of the subscriber stations MS, as indicated symbolically in FIG. 3.
  • this periodicity is sufficient for the synchronization of the base stations BS1, BS2, BS3 if the generation of the time base in the base stations BS1, BS2, BS3 is sufficiently precise technical means such as local oscillators
  • the periodicity with which the base station synchronization sequence ebs is sent can advantageously be signaled to the general organizational channel BCCH by the base stations BS1, BS2, BS3, so that the subscriber stations MS are shown the time frame for which the synchronization channel SCH is not available to them may use their own synchronization.
  • the synchronization method according to the invention is based on the simultaneity of the transmission of the base station synchronization sequences ebs, but can e.g. can be modified by additional offset values in such a way that a constant, rigid time shift is achieved between the transmission times of two base stations BS2, BS3.
  • This is particularly advantageous if different cell sizes are to be supplied by the base stations and m predeterminable zones, for example the transition between the two cells (important for handover), are to receive the transmissions from the further base stations BS2, BS3 simultaneously at the location of the base station BS1. If the cell edge is not exactly in the middle between the base stations and thus the respective distance is different, the offset is used to adapt to the real transmission time.

Landscapes

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

Abstract

Selon l'invention, au moins une séquence de synchronisation est émise dans chaque cas par des stations de base dans un canal de synchronisation pour synchroniser des stations radioémettrices-réceptrices. De plus, au moins une séquence de synchronisation de stations de base est émise par les stations de base dans le canal de synchronisation. Les séquences de synchronisation de stations de base d'au moins deux autres stations de base adjacentes sont reçues par la station de base concernée et prises en compte pour la synchronisation.
PCT/DE2000/000785 1999-03-15 2000-03-13 Procede de synchronisation de stations de base d'un systeme de transmission radio WO2000055991A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE1999111480 DE19911480C2 (de) 1999-03-15 1999-03-15 Verfahren zur Synchronisation von Basisstationen eines Funk-Kommunikationssystems
DE19911480.3 1999-03-15

Publications (1)

Publication Number Publication Date
WO2000055991A1 true WO2000055991A1 (fr) 2000-09-21

Family

ID=7901031

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2000/000785 WO2000055991A1 (fr) 1999-03-15 2000-03-13 Procede de synchronisation de stations de base d'un systeme de transmission radio

Country Status (2)

Country Link
DE (1) DE19911480C2 (fr)
WO (1) WO2000055991A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19916064C2 (de) * 1999-04-09 2003-02-20 Siemens Ag Synchronisationsverfahren für Basisstationen
DE10125013A1 (de) * 2001-05-22 2002-11-28 Siemens Ag Verfahren zur Synchronisation von Basisstationen in einem Funk-Kommunikationssystem
DE10331311B4 (de) * 2003-07-10 2008-02-07 Siemens Ag Verfahren zur Synchronisation eines in Funkzellen aufgeteilten Funkkommunikationssystems

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5519759A (en) * 1993-05-28 1996-05-21 Siemens Aktiengesellschaft Method for the synchronization of base stations in a multicellular, wireless telephone system
WO1999000912A1 (fr) * 1997-06-27 1999-01-07 Telefonaktiebolaget Lm Ericsson (Publ) Synchronisation d'une station mobile dans un systeme de communications a spectre disperse
WO1999012295A1 (fr) * 1997-08-29 1999-03-11 Telefonaktiebolaget Lm Ericsson (Publ) Recherche de cellule dans un systeme de communications a acces multiple par difference de code (amdc)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE468266B (sv) * 1991-04-12 1992-11-30 Ericsson Telefon Ab L M Foerfarande att synkronisera en radiomottagare till en inkommande radiosignal
CA2107606A1 (fr) * 1992-10-07 1994-04-08 Keishi Matsuno Methode de synchronisation de stations de base et systeme de radiocommunication mobile utilisant cette methode
DE19818325A1 (de) * 1998-04-23 1999-10-28 Siemens Ag Verfahren zum Betreiben eines Funk-Kommunikationssystems
EP0954122A1 (fr) * 1998-04-28 1999-11-03 Siemens Aktiengesellschaft Méthode pour la gestion d'un système de communication radio et tel système
DE19827700C1 (de) * 1998-06-22 2000-05-11 Siemens Ag Verfahren auf Basisstation zur Übertragung von Organisationsinformationen in einem Funk-Kommunikationssystem

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5519759A (en) * 1993-05-28 1996-05-21 Siemens Aktiengesellschaft Method for the synchronization of base stations in a multicellular, wireless telephone system
WO1999000912A1 (fr) * 1997-06-27 1999-01-07 Telefonaktiebolaget Lm Ericsson (Publ) Synchronisation d'une station mobile dans un systeme de communications a spectre disperse
WO1999012295A1 (fr) * 1997-08-29 1999-03-11 Telefonaktiebolaget Lm Ericsson (Publ) Recherche de cellule dans un systeme de communications a acces multiple par difference de code (amdc)

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LAGRANGE X ET AL: "AUTONOMOUS INTER BASE STATION SYNCHRONISATION VIA A COMMON BROADCAST CONTROL CHANNEL", PROCEEDINGS OF THE VEHICULAR TECHNOLOGY CONFERENCE,US,NEW YORK, IEEE, vol. CONF. 44, 1994, pages 1050 - 1054, XP000496838, ISBN: 0-7803-1928-1 *

Also Published As

Publication number Publication date
DE19911480C2 (de) 2003-06-18
DE19911480A1 (de) 2000-09-28

Similar Documents

Publication Publication Date Title
DE602005003550T2 (de) Verfahren zur OFDM Datenübertragung in einem mobilen Mehrzellen-Netzwerk mit Pilotsymbolen zur Kanalschätzung, und entsprechende Basisstation, Basisstationkontroller, Mobilnetzwerk
DE69816347T2 (de) VERFAHREN ZUR DATENüBERTRAGUNG IN EINEM ZELLULAREN üBERTRAGUNGSSYSTEM
DE19840232C1 (de) Verfahren und Funk-Kommunikationssystem zur Synchronisation von Teilnehmerstationen
EP1118175B1 (fr) Procede pour faire fonctionner sans perturbation au moins deux stations de base
EP0954122A1 (fr) Méthode pour la gestion d'un système de communication radio et tel système
DE19810285A1 (de) Verfahren, Funk-Kommunikationssystem und Mobilstation zum Bestimmen von Kanaleigenschaften
EP1163746B1 (fr) Procede et systeme de communication radio pour la synchronisation de stations d'abonnes
EP1226666B1 (fr) Procede de synchronisation d'une transmission de signal ascendente dans un systeme de communication radio
DE19911480C2 (de) Verfahren zur Synchronisation von Basisstationen eines Funk-Kommunikationssystems
DE10237330A1 (de) Verbesserungen in einem Funk-Kommunikationssystem
WO2001043307A2 (fr) Procede de maintien d'une transmission de signaux synchronisee dans le sens ascendant dans un systeme de radiocommunication
WO2002011486A1 (fr) Procede pour la differenciation de voies logiques dans une voie de transmission physique utilisee en commun d'un systeme de communication radio
DE19858358A1 (de) Verfahren zur Zeitsychronisation von Funkstationen in einem Funk-Kommunikationssystem
EP1108342A1 (fr) Procede de transmission d'informations vocales dans un systeme de communication radio
WO2001074021A1 (fr) Procede pour signaler le debut d'un canal logique dans un canal de transmission physique utilise en commun d'un systeme de radiocommunication
EP1027815A2 (fr) Systeme de communication radio et dispositif de commande
EP1060579B1 (fr) Procede et systeme de radiotelecommunication pour transmettre des donnees
DE19851288C1 (de) Verfahren zur Signalübertragung in einem Funk-Kommunikationssystem
WO2000016502A1 (fr) Procede et systeme de radiocommunication pour synchroniser des postes d'abonnes
DE19953879C2 (de) Verfahren zur Signalübertragung in einem Funk-Kommunikationssystem und Basisstation eines Funk-Kommunikationssystems
DE19938747A1 (de) Verfahren zur Kanalschätzung in einem Funk-Kommunikationssystem
DE19841464C2 (de) Verfahren und Funk-Kommunikationssystem zum Bereitstellen eines Organisationskanals
EP1773084A1 (fr) Déplacement des resources de radio pour moyenner l'interference inter-cellulaire
DE10106807B4 (de) Verfahren zum Synchronisieren von Stationen in einem Funk-Kommunikationssystem, insbesondere Mobilfunksystem
EP1110333A1 (fr) Procede permettant de faire fonctionner un systeme de communication radio, et un tel systeme de communication radio

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR CN JP 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

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