DE10315059A1 - Data communication method e.g. for transmission of packets in cellular communication system, involves dividing packets for transmission on transmission frameworks, which are divided into time slot - Google Patents

Abstract

The method involves dividing packets for transmission on transmission frameworks, which are divided into a time slot. The data in each time slot has a message (HS-PRACH NT) contained in its header. In a radio cell of the communication system a number M of common upward connection channels (HS-PRACH1, HS-PRACH2) and a number N of common downward connection channels are made available. The terminal (UE) from the quantity of the common upward connection channels selects a common upward connection channel. The terminal, after a successful transmission of the header by the upward connection channel packets are sent by fixed access time slot. The base station, for each received packet over a common downward connection channel sends a confirmation to the terminal after a constant time interval. This transmitting time is indicated as one time interval, which of the transmitting time of the message part, the transmission frame length of the common upward connection channel, has a minimum given by the communication system and a maximum transmission frame length depending on a minimum and maximum time deviation between an upward connection transmission and a downward connection transmission. The base station selects between the choice of the common upward connection channel and the downward connection channel. An independent claim is included for a terminal, a base station, and a communication system.

Description

The The invention relates to a method for transmitting data via a packet-oriented common channel. Furthermore, it affects one Terminal, a base station and a communication system.

For transmission data in a communication system often becomes shared transmission resources, like radio channels, which can be accessed by several terminals. An elaborate time In this case, coordination ("scheduling") is required required to avoid collisions between data transfers of individual terminals to avoid.

This is now based on an example of a UMTS (Universal Mobile Telecommunications System) standard working communication system portrayed. For Definitions and explanation of abbreviations please refer to the description of the figures.

The following describes packet data transmission via the random access channel (RACH) or the forward access channel (FACH) according to the current UMTS standard release 5. The underlying protocol architecture is in 1 shown. This architecture exists both in the mobile terminal UE (User Equipment) and in the UMTS communication system UTRAN (UMTS Terrestrial Radio Access Network), consisting of a base station (= base station) and RNC (Radio Network Controller).

1 shows the UMTS protocol architecture with layer 1 or "physical layer", layer 2 or "radio link layer" and the lower layer 3 of the OSI (Open System Interconnection) model, which contain the protocols of the UMTS air interface , This architecture exists both in the mobile end device (User Equipment, UE) and in the UMTS radio network (UMTS Terrestrial Radio Access Network, UTRAN), which, as described under point 1, can include a base station and RNC.

The respective peer-to-peer, i.e. between two equivalent units, Protocols in the UE and UTRAN terminals exchange protocol data units (Protocol Data Units, PDUs) from each other by the services the underlying protocol layers for the transport of the PDUs. Each protocol layer offers itss to the layer above it Services at so-called service access points.

This Service access points are generally used to better understand the architecture common with a unique name, e.g. logical channels, transport channels or "radio bearer", that's the service the layer 2 for the transfer of user data from the UE terminal to the UTRAN.

For data transfer take protocols at their service access points service data units or "Service Data Units "SDU on and deliver PDUs generated from it to the layer below them; PDUs from upper layers are therefore identical to the SDUs of the underlying layer.

• – die Funk-Ressourcen-Kontrollschicht bzw. "Radio Resource Control layer" (RRC)
• – die Packetdaten-Konvergenzprotokollschicht bzw. "Packet Data Convergence Protokoll-Layer" (PDCP)
• – die Funk- bzw. VielfachfunkKontrollschicht bzw "Broadcast /Multicast Control-layer" (BMC)
• – die Funkverbindungskontrollschicht bzw. "Radio Link Control Layer" (RLC)
• – die Mediums-Zugangsschicht bzw. "Medium Access Control Layer" (MAC)
• – und die physikalische Schicht (PHY).

In the 1 The protocol layers shown are:

• - the radio resource control layer (RRC)
• - the packet data convergence protocol layer or "packet data convergence protocol layer" (PDCP)
• - the radio or multiple radio control layer or "broadcast / multicast control layer" (BMC)
• - the radio link control layer (RLC)
• - the medium access control layer (MAC)
• - and the physical layer (PHY).

In the 1 The protocol architecture shown is not only divided horizontally into the layers and units already mentioned, but also vertically into the control level or C level ("C plane") and the user level or U level (" U-plane "). Only control data required for establishing and maintaining a connection and which are generated in the RNC or Terminal UE itself are transmitted via the C-plane, whereas the actual user data are transported from higher layers via the U-plane.

In the area of the U-plane, the service access point at which non-UMTS-specific protocols can use the transmission service of the UMTS air interface is referred to as the "radio bearer" RB. RBs are therefore offered above Layer 2, depending on the protocols used, above PDCP, BMC or RLC and transmit data transparently from the UE terminal via the UMTS air interface to the RNC and vice versa. When such an RB is set up, a certain transmission service quality or "Quality of Service" QoS is defined for this transmission, which is characterized, for example, by a certain guaranteed data rate or a maximum transmission delay.

in the The area of the C-plane is called the service access points at which the RRC protocol of the lower layer 3 the transmission service of the UMTS air interface can use as a signaling radio bearer or "Signaling Radio Bearer" SRB. Transport SRBs Messages from higher Layer 3 instances from sender to receiver or vice versa or in both directions. Furthermore, the RRC units of sender and receiver act via the SRBs the transmission parameters for one Connection from which the units of layer 2 and the Layer 1 can be configured or reconfigured.

There the data streams an RB is either continuous or in packets of any length, it is the job of the RLC protocol to split or merge the data stream into packets. It the RLC-SDUs are divided into RLC-PDUs or the RLC-SDUs assembled into RLC PDUs. Depending on the respective RLC transmission mode, the transparent mode or "Transparent Mode "TM, the reconfirmation free Modus or "Unacknowledged Fashion "UM or the Reconfirmation mode or "Acknowledged Fashion "AM will RLC-PDUs may also have an RLC "head" or RLC "header", the RLC specific Contains control data, added. About that the RLC layer also stores the data present on an RB in an RLC buffer until they are below the RLC Layers across the air interface can be transported. The RLC layer passes the RLC PDUs of the resulting after division or assembly MAC layer for further transmission. The RLC layer is modeled so that there is an independent RLC entity or "RLC entity" per RB.

The Service access points at which the MAC layer offers its services, are called logical channels. Logical channels differ in the type of data transmitted on them become. A distinction is therefore made between logical channels on which terminal-specific ones User data about the assigned traffic channel or "Dedicated Traffic Channel" DTCH, terminal-specific Control data on the assigned control channel or "Dedicated Control Channel" DCCH or general Control data on the general control channel or "Common Control Channel" CCCH transmitted become.

For the transfer of data about the air interface is not primarily relevant to what. transfer is, but how the data is transmitted become. Therefore, the physical layer that encodes of the data, the modulation, the radio frequency technology and the antenna contains service access points are available to the MAC layer, which are characterized by this how the data is transmitted are: the so-called transport channels.

It takes place on the transport channels there is no longer a distinction between useful and control data. With the transport channels a distinction is made in principle between terminal-specific channels or "dedicated channels" DCH and common ones channels or "common channels", such as the forward access channel or "Forward Access Channel "FACH and the random access channel or "random Access Channel "RACH. As common channels, the FACH and RACH are not a specific terminal UE assigned and can can therefore be used by all UE terminals.

The The task of the MAC layer in the transmitter is to transfer the data to a logical channel above the MAC layer, on the transport channels of the physical Show layer, or in the receiver on transport channels distribute received data to logical channels. Every transport channel is for this with a set of fixed parameters, for example the transmission frame length TTI or the coding scheme for the transfer preconfigured the data.

Out a further set of variable parameters (length of an RLC PDU, number of Transport blocks) the MAC layer can be used for the current transmission best choose and so the data transfer influence dynamically. A valid one Setting all parameters for a transport channel is called Transport Format TF. The Set of all sorts Settings for a transport channel is called transport Format set TFS. In a TFS, the individual TFs are indicated by an indicator characterized. This indicator is called the Transport Format indicator Designated TFI. Only the variable or dynamic parameters of the TFs vary within a TFS. At some point is for only one transport format is set for each transport channel. The amount the set for all existing transport channels at a certain point in time Transport formats means Transport format combination or "Transport Format Combination" TFC.

Out the for valid every transport channel Transport formats result in a large variety of possible Combinations for all transport channels and theoretically could each of these combinations result in a TFC. The number is practical the actually At the same time, combinations of transport formats allowed limited. The set of all permitted TFCs becomes the transport format combination record or "Transport Format Combination Set "TFCS called.

For the up-, Removal and reconfiguration of transport channels, logical channels and RBs or SRBs and negotiating all parameters of the Layer 2 protocols the RRC protocol is responsible. This protocol is also present in the terminal UE and in the base station or RNC, and it uses the transmission services, which the RLC layer is available the SRBs to send RRC messages.

With the transmission parameters negotiated between the RRC protocols then configured the different Layer 2 protocols. For example is for each transport channel when setting up or reconfiguring between A TFS is negotiated in the RRC protocols and the TFCS valid for all transport channels is transmitted. Both are then configured in the MAC layer, so that the MAC Mapping of the logical channels on the transport channels can make.

About the dynamic selection of a TFC for any transmission frame length beyond the MAC layer has the task of arriving on the different RBs Taking data into account of for distribute the RB set QoS on the transport channels. Doing so from the RRC layer negotiated, for example, when setting up and reconfiguring RBs, what logical channels on which transport channels are to be mapped, with several transport channels being assigned to each transport channel can be.

The The sending MAC layer searches for each transmission frame length and for each Transport channel from a transport format, in total a TFC, and determines from which logical channels data in the considered one Transfer TTI become. Then the MAC layer shares the corresponding RLC units the one belonging to the respective TF RLC-PDU-size (unless it is for the duration of the connection is constant) and the number of expected RLC PDUs with. RLC then segments the data from the RLC buffer accordingly the RLC-PDU size and passes the corresponding number of RLC PDUs on the corresponding logical Channel to the MAC layer. This adds the data if necessary a MAC "header", the MAC specific Contains control data, added and passes the generated MAC PDUs, i.e. transport blocks, for a transport channel to the physical layer, which is then used to transport the data via the UMTS air interface within a TTI.

• – Handhabung der Übertragung von Datenpaketen mit unterschiedlichen Prioritäten eines Teilnehmers über den gemeinsamen Transportkanal,
• – Übertragung von Datenpaketen unterschiedlicher Teilnehmer über denselben gemeinsamen Kanal entsprechend ihrer Prioritäten,
• – Identifikation von Teilnehmern auf gemeinsamen Kanälen,
• – Multiplexen/De-Multiplexen von Datenpaketen,
• - Messung des Datenaufkommens.

The MAC layer also has the following functions:

• Handling of the transmission of data packets with different priorities of a subscriber via the common transport channel,
• Transmission of data packets from different participants over the same common channel according to their priorities,
• - Identification of participants on common channels,
• Multiplexing / de-multiplexing of data packets,
• - measurement of data volume.

• – MAC-b ist die Funktionseinheit, die für die Handhabung des Broadcastkanals zuständig ist. Hierüber werden Systeminformationen zu allen Teilnehmern einer Funkzelle übertragen.

In detail, the MAC protocol layer consists of the following three functional units, depending on the type of transport channels:

• - MAC-b is the functional unit that is responsible for handling the broadcast channel. This is used to transmit system information to all participants in a radio cell.

in the UMTS FDD mode enables the "Common Channel "PRACH the Uplink transmission of burst traffic, e.g. signaling information or user data, up to 120 kilobits per second (kbps) as a gross data rate. Maximum can up to 16 PRACHs can be configured in one cell. The configuration the PRACHs is in the system information blocks SIB 5 and 6 via the Broadcast channel or "broadcast channel "BCH in transferred to the cell. Within SIB 5 / SIB 6 the configuration is for everyone PRACH in the IE information element, the so-called PRACH system information list or "PRACH system information list ". Table 1 shows the list of information elements in “PRACH System information list ".

Table 1: Information elements of the "PRACH system information list" after Release 5

• – PRACH Info: Hierbei wird die Konfiguration des PRACHs hinsichtlich der verfügbaren Signaturen, Zugriffszeitschlitze bzw. "Access Slots" AS, Spreizfaktoren SF für den Datenteil sowie des für die Präambel verwendeten Verwürfel- bzw. "Scrambling"-Codes signalisiert;
• – Transport channel identity: Gibt die Identität des RACH-Transportkanals an, welcher auf den PRACH abgebildet ist;
• – RACH TFS: Gibt die Menge der erlaubten Transportformate für den konfigurierten RACH an;
• – RACH TFCS: Gibt die Menge der erlaubten Transportformat-Kombinationen für den konfigurierten RACH an;
• – PRACH partitioning: Basierend auf die im IE "PRACH info" konfigurierten Signaturen und Zugriffszeitschlitze AS werden in diesem Informationselement bis zu acht Zugriffsserviceklassen ASC signalisiert. In jeder ASC kann jeweils eine Untermenge von den insgesamt verfügbaren Signaturen und Zugriffszeitschlitzen konfiguriert werden, so dass eine ASC eine Unterteilung bzw. Partition der PRACH-Ressourcen darstellt;
• – Persistence scaling factors: Gibt die Übertragungswahrscheinlichkeiten an, mit der eine RACH-Übertragungsprozedur von der MAC-Protokollschicht gestartet wird;
• – AC-to-ASC mapping table: Hiermit wird die Abbildung der Access Classes zu den Access Service Classes signalisiert, mit eine "idle mode"-UE in der Lage ist, eine initiale Nachricht im Uplink zu senden;
• – Primary CPICH DL TX power: Die Leistung mit der der P-CPICH in der Funkzelle gesendet wird, wird zur Berechnung der initialen Ausgangsleistung der PRACH Präambel herangezogen;
• – Constant value: Konstanter Wert, der zur Berechnung der initialen Ausgangsleistung der PRACH Präambel herangezogen wird;
• – PRACH power offset: Gibt die Parameter für die PRACH Präambelübertragung an, wie die Schrittweite für die Leistungseinstellung und die maximale Anzahl der Präambel-Retransmissionen;
• – RACH transmission parameters: Gibt die Parameter zur Kontrolle der RACH-Übertragung auf der MAC-Protokollschicht-Ebene an, weitere Details sind im Zusammenhang mit Tabelle 4 näher erläutert;
• – AICH info: Gibt die Parameter für den jeweiligen PRACH assozierten AICH an.

The function or meaning of the individual information elements is as follows:

• - PRACH Info: The configuration of the PRACH with regard to the available signatures, access time slots or "access slots" AS, spreading factors SF for the data part and the scrambling or scrambling code used for the preamble is signaled;
• - Transport channel identity: specifies the identity of the RACH transport channel, which is mapped to the PRACH;
• - RACH TFS: Specifies the number of permitted transport formats for the configured RACH;
• - RACH TFCS: Specifies the number of permitted transport format combinations for the configured RACH;
• - PRACH partitioning: Based on the signatures and access time slots AS configured in IE "PRACH info", up to eight access service classes ASC are signaled in this information element. A subset of the total available signatures and access time slots can be configured in each ASC, so that an ASC represents a subdivision or partition of the PRACH resources;
• Persistence scaling factors: specifies the transmission probabilities with which an RACH transmission procedure is started by the MAC protocol layer;
• - AC-to-ASC mapping table: This signals the mapping of the access classes to the access service classes, with which an "idle mode" -UE is able to send an initial message in the uplink;
• - Primary CPICH DL TX power: The power with which the P-CPICH is sent in the radio cell is used to calculate the initial output power of the PRACH preamble;
• - Constant value: Constant value that is used to calculate the initial output power of the PRACH preamble;
• - PRACH power offset: Specifies the parameters for the PRACH preamble transmission, such as the step size for the power setting and the maximum number of preamble retransmissions;
• - RACH transmission parameters: Specifies the parameters for controlling the RACH transmission at the MAC protocol layer level, further details are explained in connection with Table 4;
• - AICH info: Indicates the parameters for the respective PRACH associated AICH.

In principle, all terminals within a UMTS cell can use the PRACHs together for data transmission. The access of the terminals to a PRACH is regulated according to the "slotted ALOHA" procedure, in which each terminal randomly selects a suitable PRACH and sends this only at the beginning of fixed time intervals, the access time slots or "access slots" AS. The length of an AS is 5120 chips, ie twice the length of a time slot in an FDD frame of 10 ms in length. Within two P-CCPCH frames, in which the condition SFN mod 2 = 0 and SFN mod 2 = 1 apply, a total of 15 AS are defined (numbered with AS # 0 to AS # 14), see 2 ,

The transfer Data in UMTS FDD mode is in the form of frames of 10 ms in length and after a timing, based on the system frame number or "System Frame Number" (SFN). The SFN will always broadcast with the system information of the radio cell transferred to the BCH / P-CCPCH. Runs per frame the SFN as a counter periodically from 0 ... 4095 (integer) high. The expression "SFN mod 2" means the mathematical modulo 2 operation of the respective SFN. The use of the randomly selected PRACH depends on this from the ASCs (Access Service Classes), which are defined in the IE “PRACH partitioning " become.

table 2 shows the parameters with which each ASC is configured. By The ASCs regulate a prioritized use of PRACH.

Table 2: Information elements of "PRACH partitioning" for ASC configuration after Release 5

The PRACH consists of a preamble part and a message part. The PRACH message part in turn consists of a control part and a data part. The random access transmission consists of one or more preambles of 4096 chip length and the actual message. A randomly selected signature s is transmitted in the preambles. After a positive confirmation (ACK) for the correct reception of the preamble on the acquisition indicator channel or "acquisition indicator channel" AICH by the base station, the terminal sends the data on the PRACH message part at a specified time based on the access time slots , In 3 an example of a random access transmission is shown, in which the terminal receives an ACK from the base station only in the second preamble. Here τ _{p – p is} the time offset between two preambles, τ _{p – m is} the time offset between the preamble and the PRACH message part and τ _{p – a is} the time offset between the start of the uplink AS, in the the terminal sends a preamble and the beginning of the corresponding downlink AS in which the base station sends the AICH. In the example after 3 a transmission time length of TTI = 10ms was selected for the PRACH message part. The following values were set for the time offsets: τ _p-p = τ _p-m = 3 AS and τ _p-a = 1.5 AS, where the length of an access time slot 5120 Chips.

The The transmission power of the PRACH message part is based on the Transmission power of the successfully sent preamble set. Furthermore become the OVSF channelization codes for the PRACH message part from the successfully transferred Preamble signature certainly. There is a maximum of 16 of these signatures, which are assigned to one of the 16 nodes in the OVSF code tree demonstrate. The signatures correspond to a code with SF = 16. Dependent The code s for the PRACH is made from the signature s Message part used.

The Number of signatures and uplink access time slots that one Terminal for data transmission via the PRACH available stand by priority of the ASCs set. Maximum can up to 8 ASCs for a PRACH can be specified, these ASCs are numbered so making RSC # 0 the highest priority and ASC # 7 the lowest priority Has. The higher the priority is, the bigger can be the number of available Signatures and the uplink access time slots (summarized in the so-called RACH subchannels) in the ASC. In "Idle Mode", the RRC layer in the terminal the ASC based on the Access Classes (AC) out. In the "Connected Fashion, however, decides the MAC layer in the terminal the ASC based on priority of the logical channels CCCH, DCCH or DTCH, about which the data on the RACH transport channel or PRACH via the Transfer air interface to UTRAN become.

The data on the data part of the PRACH message part can be transmitted in three different modes, which are configured by the RLC layer in the terminal: "Transparent Mode" TM, "Unacknowledged Mode" UM and "Acknowledged Mode" AM. In the case of a packet data transmission (AM) to be confirmed, after the PRACH message part has been sent, the terminal waits for confirmation from the base station via the secondary common control physical channel (S-CCPCH) as a separate return channel. Within the UTRAN, the RLC layer in the RNC checks all received data packets for possible transmission errors and notifies the terminal of the respective test result. For each data packet received without errors, a positive confirmation (ACK) is transmitted via the return channel. Accordingly, a negative acknowledgment (NACK) is transmitted over the return channel for each data packet received incorrectly. According to the protocol, the ACKs / NACKs are generated by the RLC in the RNC and transmitted via the FACH transport channel from the MAC layer to the physical layer, where the FACH is then mapped to the S-CCPCH and sent from the base station to the terminal via the air interface. If the terminal receives the message that a certain data packet has been transmitted incorrectly, the terminal repeats the transmission (retransmission) for the incorrectly sent data packet to the PRACH message section after randomly selected waiting times, whereby the entire random access procedure consisting of preamble and message transmission is restarted.

4 shows an example of the timing of the PRACH message part and S-CCPCH with TTI = 10ms in the case of a packet data transmission (AM) to be confirmed. After the RLC layer in the terminal has sent the data packets to the lower protocol layers via one of the logical channels DCCH or DTCH, the timer or timer "Timer poll" is started in the RLC. Within the time set by the timer, the terminal expects a positive one or negative confirmation on the S-CCPCH from the UTRAN If the timer expires without neither an ACK nor a NACK being received, the terminal interprets this as a NACK and thus triggers a new transmission or "retransmission".

Generally hangs the Number of physical channels in a mobile radio system depending on the transmission capacity specified.

For the transfer a P-CCPCH of the system information is sufficient. For data transfer to S-CCPCH, however depends on them Number depending on the configuration of the radio cell, i.e. for how many Terminals the cell is laid out. By default, up to 16 S-CCPCHs can be configured become. The number of the S-CCPCH is expressed by the index k. The transfer a certain S-CCPCH with index k is always temporal offset relative to the transmission of the P-CCPCH, for the condition applies "SFN mod 2 = 0 "." Mod "denotes here the modulo operation.

This time offset τ _{S-CCPCH, k} is specified in chips.

If the terminals now receive the P-CCPCH in a cell, then read the system information and at the same time determine the time transfer clock the cell.

equivalent to this can be confirmed Packet data transmission (AM) can also be initiated by UTRAN by adding signaling information or user data are sent to a terminal via the S-CCPCH. After sending the data on the S-CCPCH, UTRAN waits for an acknowledgment (ACK / NACK) from Terminal over the PRACH as a separate return channel.

• – Im Idle Mode erfolgt dieses Abbilden auf Basis der IMSI.
• – Beim Übergang von Idle Mode zu Connected Mode erfolgt das Abbilden auf Basis einer „Inital UE identity".
• – Im Connected Mode ist das Abbilden auf Basis der vom UTRAN vergebenen temporären U-RNTI festgelegt.

Like the PRACHs, the S-CCPCHs are also common channels. A maximum of 16 S-CCPCHs can be configured in a cell, and their configuration is also transmitted in the SIB 5 or SIB 6 via the "broadcast channel" BCH in the cell. UTRAN sends signaling information or user data to the terminals on the S-CCPCHs. So that the terminals know on which S-CCPCH the communication system sends data to you, S-CCPCHs are mapped to terminals based on identities:

• - In idle mode, this mapping is based on the IMSI.
• - During the transition from idle mode to connected mode, the mapping is based on an "Inital UE identity".
• - In Connected Mode, mapping is based on the temporary U-RNTI assigned by UTRAN.

Per S-CCPCH can maximum 8 FACH transport channels are mapped so that per S-CCPCH also data for maximum 8 different terminals transmitted can be. But since UTRAN is not constantly data to a terminal In principle, every terminal must send the corresponding S-CCPCH Detect your S-CCPCH continuously and check whether there is relevant data for you or not. A k-th S-CCPCH with a time offset OS-CCPCH, k relative to the system frame number SFN of the P-CCPCH from the base station Posted. The BCH transport channel is shown on the P-CCPCH, above which all Terminals in the cell receive the relevant system information can.

outgoing from this state of the art it is the task of. Invention one Scheduling for a transmission over together used radio channels indicate the probability of access collisions across from reduced the prior art.

This The object is achieved by a method according to the features of the independent claim 1 solved. Advantageous refinements can be found in the dependent claims.

The invention is based on the idea of choosing the common uplink channel for a packet data transmission also select the downlink channel via which an acknowledgment regarding the receipt of a data packet is sent back to the terminal.

Consequently the terminal already knows the downlink channel, so it doesn't it is necessary that this is done via a terminal-specific Coding of the data determined. The computing effort in the terminal can thus be reduced become.

The Time to send it back of confirmation is about Uplink connection parameters and system parameters.

If these parameters are known to the terminal or communicated to it it also knows a period within which it receives an acknowledgment. Consequently the terminal does not have to continue the downlink channel as before observe.

These parameters depend on the details of the transmission, which are specified in more detail below:
A packet can be distributed over several transmission frames for transmission, which in turn each comprise one or more time slots. Each time slot contains a preamble part and a message part. The message part in turn comprises a data part and a control part.

at the parameters are in particular a broadcast time of the Message part, a transmission frame length of Uplink and a minimum specified by the communication system and maximum transmission frame length.

In summary This has the advantage that the computing effort or the complexity of the recipient of the Downlink channel, So the terminal can be reduced since the terminal is not as before, it was given to him on the basis of his identity number assigned downlink channel must watch, but a time period in which feedback is to be expected from the base station.

This The method is particularly advantageous when using UMTS FDD systems across from the prior art shortened transmission frame can be used because the detection effort becomes higher.

Shortened transmission frames can the likelihood of simultaneous access collisions Reduce access to multiple terminals to a common resource.

• – Neue kürzere Übertragungsrahmen der Länge TTI = 1, 2, 3, 4 oder 5 Zeitschlitze für die Transportkanäle RACH und FACH, welche im Rahmen der Anmeldung als HS-RACH und HS-FACH bezeichnet werden.
• – Anwendung einer Multicode-Übertragung auf die physikalischen Kanäle PRACH und S-CCPCH, welche im Rahmen der Anmeldung als HS-PRACH und HS-SCCPCH bezeichnet werden.
• – Eine Leistungskontrolle auf dem HS-PRACH kann daran angepasst werden.
• – Anwendung eines zusätzlichen ARQ-Verfahrens zwischen Terminal und Basisstation unabhängig vom Funkverbindungsmodus bzw. "Radio Link Control Mode".

Based on this, an efficient packet data transmission method in UMTS FDD mode via the common channels RACH / PRACH in the uplink and FACH / S-CCPCH in the downlink can contain all or a selection from the following features:

• - New shorter transmission frames of length TTI = 1, 2, 3, 4 or 5 time slots for the transport channels RACH and FACH, which are referred to as HS-RACH and HS-FACH in the registration.
• - Application of a multicode transmission to the physical channels PRACH and S-CCPCH, which are referred to as HS-PRACH and HS-SCCPCH in the context of the registration.
• - A performance check on the HS-PRACH can be adjusted accordingly.
• - Use of an additional ARQ procedure between the terminal and base station regardless of the radio connection mode or "Radio Link Control Mode".

This allows efficient packet data transmission in the case of higher ones Traffic loads in a cell. In particular, the delay of data transfer as a result of collisions and interference from retransmissions reduced.

On have the appropriate terminal or base station in addition to a transmitting / receiving unit, a processor unit which to carry out of such a method is suitable.

Further Advantages of the invention are based on the configurations shown in the figures explained. Show it:

1 : A schematic of the UMTS protocol architecture;

2 : Definition of the access time slots;

3 : Sequence of a random access transmission in UMTS FDD mode;

4 : PRACH / S-CCPCH timing ("timing");

5 : HS-PRACH / HS-SCCPCH time planning.

First of all In order to explain given the background of the invention the following definitions become.

1. Definitions

at a communication system or communication network is a data exchange structure. It can do this a cellular cellular network that, for example according to the GSM (Global System of Mobile Communications) standard or the UMTS (Universal Mobile Telecommunications System) standard works. In a communication system there are generally terminals and base stations intended. In UMTS the communication system or radio transmission network points at least base stations, here also called "NodeB", and radio network control units or "Radio Network Controller" (RNC) for connection of the individual base stations. The terrestrial radio access network or "Universal Terrestrial Radio Access Network "UTRAN is the radio-technical part of a UMTS network in which, for example the radio interface is also made available. A radio interface is standardized and defines the entirety of the physical and protocol specifications for the data exchange, for example the modulation method, the Bandwidth, the frequency swing, access procedures, security procedures or mediation techniques. The UTRAN therefore includes at least Base stations and at least one RNC.

at cellular Mobile radio systems can different radio transmission technologies be provided that define how the physical connection resources be divided. In the case of UMTS, a frequency multiple access mode or "frequency division" is currently in use Duplex "(FDD) mode provided, as well as different time multiple access modes or "Time Division Duplex" (TDD) modes. In FDD mode the data transfer takes place of so-called "up" and "down link" connections different frequencies by frequency division multiplex, while at data transfer from the two TDD modes Up and down link time division multiplexed on the same frequency.

A Base station is a central unit in a communication network, which in the case of a cellular Cellular network terminals or communication terminals within a cell of the mobile radio network is operated via one or more radio channels. The base station provides the air interface between the base station and terminal ready.

It takes over the handling of radio operations with the mobile participants and monitored the physical radio link. It also transmits the user and status messages to the terminals. The base station has no switching function, but just a supply function. Includes a base station at least one transmitting / receiving unit.

On Terminal can be any communication terminal via which a user communicates in a communication system. It fall for example, mobile terminals or portable computers with a radio module underneath. A terminal is often also referred to as a "mobile station" (MS) or in UMTS "user equipment" (UE).

in the Mobile radio is differentiated between two connection directions. The forward direction or "Downlink" (DL) the direction of transmission from the base station to the terminal. The reverse direction or uplink (UL) denotes the opposite direction of transmission from the terminal to the base station.

In Wideband transmission systems, such as a UMTS cellular network, a channel is a sub-area one available standing total transmission capacity. As a radio channel becomes a wireless communication path in the context of this application designated.

In a mobile radio system, for example UMTS, there are two types of physical channels for the transmission of data: dedicated channels or "dedicated channels" and shared ones or "common channels". With dedicated channels, a physical resource is only reserved for the transmission of information for a specific terminal. The common channels can transmit information that is intended for all terminals, for example the primary common physical control channel or "Primary Common Control Physical Channel" (P-CCPCH) in the downlink, or all terminals share one another physical resource, since each terminal may only use it for a short time. This is the case, for example, with the physical random access channel or "physical random access channel" (PRACH) in the uplink.

at the transmission over a Common channel or dedicated channel, the data is next to one Bandwidth spreading using a spreading code or "channelization codes" for more robust transmission additionally a scramble or "scrambling" procedure for identification subjected to a specific connection. To do this will depend the direction of transmission, of the channel type and radio transmission technology different types of scramble codes or "scrambling codes ". While a bit from a data sequence is usually referred to as a symbol, a bit of a bandwidth-spread sequence is called a chip.

In Mobile radio systems, such as those based on UMTS, In addition to circuit-switched or "circuit switched" services, packet-oriented or "packet switched" services are also provided.

In particular in 2nd or 3rd generation mobile radio systems, such as the GSM or UMTS, the data transmission takes place over the Radio channel generally in a fixed structure, the transmission frame, which is often referred to as just a frame. A transmission framework therefore represents the periodic basic time structure with which data physically transmitted become. In UMTS is a frame 10 ms. To carry out of certain functions, such as channel estimation and performance control, a frame is divided into time slots, for example UMTS in 15 time slots. A time slot is therefore a permanently assigned one Time period within a transmission frame.

On Basis of the temporal structure, consisting of frames and time slots, you can use other temporal substructures, for example subframes or "Subframes". For example could one defines a subframe in UMTS, the three time slots should include, so that a frame is then composed of 5 subframes.

A transmission time interval or "transmission time interval "(TTI) denotes the length of time , about the data that was encoded together due to scrambling, e.g. a so-called "scrambling" or "interleaving", spread out over time become. For example, a TTI can be specified in terms of time slots become.

In order to the transmission time interval, in the data from the medium access layer or "Medium Access Layer" (MAC) (OSI layer 2, OSI: Open System Interconnection) to the physical layer (OSI layer 1) in the form of so-called transport blocks (= combination of data packets fixed length) will be designated. Furthermore, the transmission time interval, in which the data is then physically transmitted via the air interface will be designated.

For example in the case for the TTI = 40ms applies, data is from the MAC layer every 40ms sent to the physical layer. On the other hand, this data then from the. physical layer transmitted within 4 frames.

2.1 Refinements of invention

a) mapping between Uplink and downlink channel

It is essential for the invention that a terminal with the selection of an uplink also the downlink selects.

in the Case of a UMTS system chooses yourself the terminal with the selection of an extended common High-speed access channel HS-PRACH also the corresponding common secondary high-speed control channel HS-SCCPCH out. In contrast, the terminal previously recognized based on its Identity number which is used to encode data on this common channel what information for it was determined.

• – die Anzahl der HS-PRACH ist gleich der Anzahl der HS-SCCPCH: In diesem Fall kann die Korrespondenz wie folgt aussehen: - dem HS-PRACH 1 ist der HS-SCCPCH 1 zugeordnet – dem HS-PRACH 2 ist der HS-SCCPCH 2 zugeordnet, und so fort.
• – die Anzahl HS-PRACH ist gröber als die der HS-SCCPCH: In diesem Fall sind einem HS-SCCPCH mehrere HS-PRACHs zugeordnet. Die Korrespondenz kann dabei wie folgt aussehen, wobei der Pfeil "→" eine Zuordnung bedeutet: – HS-PRACH1 → HS-SCCPCH1 – HS-PRACH2 → HS-SCCPCH1 – HS-PRACH3 → HS-SCCPCH2 – HS-PRACH4 → HS-SCCPCH3 – usw.
• – die Anzahl HS-PRACH ist kleiner als die der HS-SCCPCH: In diesem Fall sind einem HS-PRACH mehrere HS-SCCPCHs zugeordnet. Die Korrespondenz kann dabei wie folgt aussehen: – HS-PRACH1 → HS-SCCPCH1 – HS-PRACH1 → HS-SCCPCH2 – HS-PRACH2 → HS-SCCPCH3 – HS-PRACH2 → HS-SCCPCH4 – usw.

There is a correspondence between HS-PRACH and HS-SCCPCH. Depending on the cell configuration, the following three cases are distinguished:

• - The number of HS-PRACH is equal to the number of HS-SCCPCH: In this case, the correspondence can look like this: - HS-PRACH 1 is assigned to HS-SCCPCH 1 - HS-PRACH 2 is HS-SCCPCH 2 assigned, and so on.
• - The number of HS-PRACH is coarser than that of HS-SCCPCH: In this case, several HS-PRACHs are assigned to one HS-SCCPCH. The correspondence can look as follows, where the arrow "→" means an assignment: - HS-PRACH1 → HS-SCCPCH1 - HS-PRACH2 → HS-SCCPCH1 - HS-PRACH3 → HS-SCCPCH2 - HS-PRACH4 → HS-SCCPCH3 - etc.
• - The number of HS-PRACH is smaller than that of the HS-SCCPCH: In this case, several HS-SCCPCHs are assigned to one HS-PRACH. The correspondence can look like this: - HS-PRACH1 → HS-SCCPCH1 - HS-PRACH1 → HS-SCCPCH2 - HS-PRACH2 → HS-SCCPCH3 - HS-PRACH2 → HS-SCCPCH4 - etc.

b) Scheduling Sequence planning the HS-SCCPCH

Farther is not a fixed time of transmission, but a time interval based of the access time slots in which the downlink channels, ie for example, the HS-SCCPCHs sent by the communication system can be. Dependent on from the respective time of transmission of the HS-PRACH message part, the length of the HS-PRACH transmission frame (TTI) and the minimum and maximum transmission frame lengths TFL min and TFL_max, can calculate the send interval for the HS-SCCPCHs by a minimum and a maximum time offset in access time slots is determined. This reduces the detection effort in the terminal, since it no longer has to continuously detect the HS-SCCPCHs.

The following applies to the minimum time offset in access time slots: AS_Nomin mod 15 = AS_No + ceil {(TFL_minHS-PRACH TTI) / AS_size + Constant delay / AS_size}

The following applies to the maximum time offset in access time slots: AS_Nomax mod 15 = AS_No + ceil {(TFL_maxHS-PRACH TTI) / AS_size + Constant delay / AS_size}

• – AS_Nomin: Die minimale Nummer des Zugriffszeitschlitzes bzw. die untere Grenze des Übertragungsintervalls bzw. der frühestmögliche Zeitpunkt, in der das Kommunikationssystem im Downlink den HS-SCCPCH zum Terminal senden kann. Entsprechend ist
• – AS_Nomax die maximale Nummer des Zugriffszeitschlitzes bzw. die obere Grenze der Übertragungsintervalls bzw. der spätmöglichste Zeitpunkt.
• – AS_No: die Nummer des Zugriffszeitschlitze, in der das Terminal im Uplink den HS-PRACH sendet.
• – Ceil: mathematischer Operator, mit der eine reelle Zahl auf eine ganze Zahl aufgerundet wird.
• – Mod: Die Modulo-Operation
• – minimale TFL: Parameter ergibt sich aus den definierten TFLs innerhalb des IE "PRACH partitioning" (Tabelle 3), welche im PRACH System information list (Tabelle 1) signalisiert wird. Wenn eine priorisierte HS-PRACH-Nutzung konfiguriert wird, dann werden unterschiedliche TFL-Werte in den ASCs definiert. Dann ist die minimale TFL diejenige TFL mit der kürzesten Länge. Hingegen, wenn keine priorisierte HS-PRACH-Nutzung konfiguriert wird, dann sind alle TFL-Werte in den ASCs gleich. Dann ist die minimale TFL gleich dieser Länge.
• – Analog hierzu ergibt sich auch die maximale TFL.
• – HS-PRACH TTI: Parameter wird im Rahmen von SIB5/6 innerhalb der PRACH system information list (Tabelle 1) signalisiert. Im besonderen erfolgt dies im IE "RACH TFS".
• – AS_size: die Länge eines Zugriffszeitschlitzes. Derzeit beträgt sie 2 Zeitschlitze. Prinzipiell können jedoch auch andere Längen definiert werden.
• – "Constant delay": ein vom Kommunikationssystem zu konfigurierender Parameter, in der die Datenverarbeitungszeit im Kommunikationssystem, die Kanalübertragungsverzögerung sowie andere Übertragungsfaktoren (wie z.B. auch die Dienstqualität) berücksichtigt wird.

The variables mean:

• - AS_Nomin: The minimum number of the access time slot or the lower limit of the transmission interval or the earliest possible time at which the communication system can send the HS-SCCPCH to the terminal in the downlink. Is accordingly
• - AS_Nomax the maximum number of the access time slot or the upper limit of the transmission interval or the latest possible time.
• - AS_No: the number of the access time slots in which the terminal sends the HS-PRACH in the uplink.
• - Ceil: mathematical operator used to round a real number up to an integer.
• - Mod: The modulo operation
• - Minimum TFL: parameters result from the defined TFLs within the IE "PRACH partitioning" (table 3), which is signaled in the PRACH system information list (table 1). If a prioritized HS-PRACH usage is configured, then different TFL values are defined in the ASCs. Then the minimum TFL is the one with the shortest length. On the other hand, if no prioritized HS-PRACH usage is configured, then all TFL values in the ASCs are the same. Then the minimum TFL is equal to this length.
• - Analogously to this, the maximum TFL also results.
• - HS-PRACH TTI: Parameters are signaled as part of SIB5 / 6 within the PRACH system information list (Table 1). In particular, this is done in IE "RACH TFS".
• - AS_size: the length of an access time slot. It is currently 2 time slots. In principle, however, other lengths can also be defined.
• - "Constant delay": a parameter to be configured by the communication system, in which the data processing time in the communication system, the channel transmission delay and other transmission factors (such as the quality of service, for example) are taken into account.

In dependence from the selected one HS-PRACH the terminal determines the send interval of the corresponding one HS-SCCPCHs and represents the recipient accordingly. Conversely, the communication system calculates after receiving the HS-PRACH message part, the send interval for the correspond HS-SCCPCH according to the formulas above. The actual time of transmission within the communication system determines this time interval on the basis the data priority, the amount of data and / or the number of terminals using the same HS-SCCPCH selected to have. A constant delay is set with the "Constant delay" parameter the data processing time in the communication system, the channel transmission delay and other transfer factors considered. This parameter is intended for the terminals when configuring the HS-SCCPCHs by collective call or "broadcast", for example via the primary common physical control channel "Primary Common Control Physical Channel "P-CCPCH signals become.

In summary the selection of the "downlink Common Channels "is not more about the participant identity, but based on the selection of the "Uplink Common Channels". Furthermore, for the "Downlink Common Channels" no fixed transmission time, but specifies a transmission interval based on the access time slots, in which the communication system stores the data based on the data priority, the amount of data and the number of participants who selected the same "Downlink Common Channel", transferred to the individual participants can.

2.2 Additional changes for one Random access transmission

• 1. Erweiterung der ASC mit neuen Parametern: Innerhalb des Informationselementes „PRACH system information list" wird im IE „PRACH partitioning" die ASC-Konfiguration um die drei Parameter Übertragungsrahmenlänge bzw. "Transmission Frame Length" (TFL), Übertragungsstartzeit bzw. "Transmission Start Time" (TST) und Übertragungszeitwahrscheinlichkeit bzw. "Transmission Start Time Probability" (TSTP) erweitert, siehe Tabelle 3. Hierdurch kann die Zeitplanung ("timing") der Random Access-Übertragung für den HS-PRACH Nachrichtenteil so eingestellt werden, so dass das Risiko von Zugriffskollisionen weiter reduziert werden kann. Tabelle 3: Informationselemente des „PRACH partitioning" zur ASC-Konfiguration der HS-PRACHs
  
  
• 2. Konfiguration und Auswahl der HS-PRACHs: Die Konfiguration der in der Zelle verfügbaren HS-PRACHs soll in SIB 5 bzw. 6 über den "Broadcast-Channel" BCH in der Zelle übertragen werden. Innerhalb von SIB 5/SIB 6 wird die Konfiguration für jeden HS-PRACH, wie Übertragungsrahmenlänge (TTI = 1, 2, 3, 4 oder 5 Zeitschlitze, wobei ein Zeitschlitz die Länge 2560 Chips hat), Spreizfaktor (SF), ASCs etc., im Informationselement „PRACH system information list" festgelegt. Jedes Terminal soll sich einen passenden HS-PRACH in Abhängigkeit der zu übertragenden Datenmenge zufällig auswählen.
• 3. Neues Übertragungsverfahren mit Kollisionsvermeidung: Der Zugriff der Terminals auf einen HS-PRACH ist nach dem "Slotted ALOHA"-Verfahren geregelt. Der HS-PRACH besteht aus einem Präambel-Teil (preamble part) und einem Nachrichtenteil (message part). Der HS-PRACH Nachrichtenteil besteht aus einem Kontrollteil und einem Datenteil. Die Präambel-Übertragung erfolgt nur zu Beginn von festen Zeitintervallen auf Basis der Zugriffszeitschlitze (AS), und die Nachrichtenteil-Übertragung erfolgt nur zu Beginn von festen Zeitpunkten auf Basis der Transmission Start Time (TST) innerhalb der Transmission Frame Length (TFL). Ein Terminal wählt sich den jeweiligen Sendezeitpunkt anhand der Transmission Start Time Probability (TSTP) zufällig aus.
• 4. Anwendung eines ARQ-Verfahren zwischen Terminal und Basisstation: Unabhängig vom RLC-Modi TM, UM oder AM soll die Basisstation den Empfang jedes HS-PRACH Nachrichtenteils von einem Terminal auf dem HS-SCCPCH bestätigen. Ein ARQ-Verfahren in der Basisstation prüft alle empfangenen Datenpakete auf mögliche Übertragungsfehler und gibt dem Terminal das jeweilige Prüfergebnis bekannt. Für jedes fehlerfrei empfangene Datenpaket wird eine positive Bestätigung (ACK) über den HS-SCCPCH übertragen. Entsprechend wird für jedes fehlerhaft empfangene Datenpaket eine negative Bestätigung (NACK) über den HS-SCCPCH übertragen. Erreicht das Terminal die Mitteilung, dass ein bestimmtes Datenpaket fehlerhaft übertragen wurde, so wiederholt das Terminal zum nächstmöglichen Zeitpunkt die Übertragung für den fehlerhaft gesendeten Datenpaket auf den HS-PRACH Nachrichtenteil.

In addition to the downlink selection and transmission interval determination, the following extensions are provided:

• 1. Extension of the ASC with new parameters: Within the information element "PRACH system information list" in the IE "PRACH partitioning", the ASC configuration by the three parameters transmission frame length or "Transmission Frame Length" (TFL), transmission start time or "transmission Start Time "(TST) and transmission time probability or" Transmission Start Time Probability "(TSTP) extended, see Table 3. This allows the timing (" timing ") of the random access transmission for the HS-PRACH message part to be set, see above that the risk of access collisions can be further reduced. Table 3: Information elements of "PRACH partitioning" for ASC configuration of the HS-PRACHs
  
  
• 2. Configuration and selection of the HS-PRACHs: The configuration of the HS-PRACHs available in the cell is to be transmitted in SIB 5 or 6 via the "broadcast channel" BCH in the cell. Within SIB 5 / SIB 6, the configuration for each HS-PRACH, such as transmission frame length (TTI = 1, 2, 3, 4 or 5 time slots, where a time slot has a length of 2560 chips), spreading factor (SF), ASCs etc. , in the information element "PRACH system information list". Each terminal should select a suitable HS-PRACH at random depending on the amount of data to be transmitted.
• 3. New transmission procedure with collision avoidance: The access of the terminals to an HS-PRACH is regulated according to the "Slotted ALOHA" procedure. The HS-PRACH consists of a preamble part and a message part. The HS-PRACH news section consists of an egg a control part and a data part. The preamble transmission takes place only at the beginning of fixed time intervals based on the access time slots (AS), and the message part transmission takes place only at the beginning of fixed times based on the transmission start time (TST) within the transmission frame length (TFL). A terminal chooses the respective transmission time at random based on the Transmission Start Time Probability (TSTP).
• 4. Use of an ARQ procedure between terminal and base station: Regardless of the RLC modes TM, UM or AM, the base station should confirm the receipt of each HS-PRACH message part from a terminal on the HS-SCCPCH. An ARQ procedure in the base station checks all received data packets for possible transmission errors and informs the terminal of the respective test result. For every error-free received data packet, a positive confirmation (ACK) is transmitted via the HS-SCCPCH. Accordingly, a negative confirmation (NACK) is transmitted via the HS-SCCPCH for each data packet received incorrectly. If the terminal receives the message that a certain data packet has been transmitted incorrectly, the terminal repeats the transmission for the incorrectly sent data packet to the HS-PRACH message part at the next possible time.

• – Kurze burstartige Datenpakete sind in einem CDMA-basierten Übertragungssystem schwieriger zu detektieren als längere Datenpakete.
• – Die Übertragungsrahmenlängen (TFL) variieren von Terminal zu Terminal in Abhängigkeit der gewählten HS-PRACHs bzw. der Access Service Classes innerhalb eines HS-PRACHs. Im ungünstigsten Fall bedeutet es, dass pro HS-SCCPCH nur Daten für ein Terminal übertragen werden kann, was eine Verzögerung der schnellen Datenübertragung zur Folge hätte.

Optimization with regard to the scheduling of HS-FACH / HS-SCCPCH is provided in particular for the following reasons:

• - Short burst-like data packets are more difficult to detect in a CDMA-based transmission system than longer data packets.
• - The transmission frame lengths (TFL) vary from terminal to terminal depending on the selected HS-PRACHs or the access service classes within an HS-PRACH. In the worst case, this means that only data for one terminal can be transmitted per HS-SCCPCH, which would result in a delay in fast data transmission.

2.3. Detailed embodiments

• – In einer UMTS-Zelle ist jeweils ein HS-PRACH und HS-SCCPCH definiert, deren Konfiguration per SIB5/SIB6 über den "Broadcast channel" zu allen Terminals übertragen werden.
• – Für den HS-PRACH und HS-SCCPCH ist die Übertragungszeitlänge TTI = 2 Zeitschlitze.
• – Es werden zwei Terminals im Connected Mode betrachtet, die sich denselben HS-PRACH und HS-SCCPCH zur Paketdatenübertragung ausgewählt haben.
• – Für den HS-PRACH ist die minimale Übertragungsrahmenlänge mit TFL_min = 4, und die maximale Übertragungsrahmenlänge mit TFL_max = 6 definiert.
• – Terminal 1 wählt sich zur Paketdatenübertragung auf dem HS-PRACH den ASC#0 aus. Dieser ist bzgl. dem neuen Übertragungsverfahren zur Kollisionsvermeidung mit folgenden Parametern konfiguriert:
• – Transmission Frame Length (TFL) = 4
• – Transmission Start Time (TST) = 4
• – Transmission Start Time Probability (TSTP) = {1/4, ¼, ¼, ¼}
• – Terminal 2 wählt sich zur Paketdatenübertragung auf dem HS-PRACH den ASC#3 aus. Dieser ist bzgl. dem neuen Übertragungsverfahren zur Kollisionsvermeidung mit ^I folgenden Parametern konfiguriert:
• – Transmission Frame Length (TFL) = 6
• – Transmission Start Time (TST) = 6
• – Transmission Start Time Probability (TSTP) = {1/6, 1/6, 1/6, 1/6, 1/6, 1/6}
• – Der Parameter "Constant delay" ist mit 3 Zeitschlitze konfiguriert.

The following assumptions apply to the exemplary embodiment:

• - One HS-PRACH and one HS-SCCPCH are defined in a UMTS cell, the configuration of which is transmitted to all terminals via SIB5 / SIB6 via the "broadcast channel".
• - For the HS-PRACH and HS-SCCPCH, the transmission time length TTI = 2 time slots.
• - Two terminals in connected mode are considered, which have selected the same HS-PRACH and HS-SCCPCH for packet data transmission.
• - For the HS-PRACH, the minimum transmission frame length is defined with TFL_min = 4 and the maximum transmission frame length with TFL_max = 6.
• - Terminal 1 selects ASC # 0 for the transmission of packet data on the HS-PRACH. The new transmission method for collision avoidance is configured with the following parameters:
• - Transmission Frame Length (TFL) = 4
• - Transmission Start Time (TST) = 4
• - Transmission Start Time Probability (TSTP) = {1/4, ¼, ¼, ¼}
• - Terminal 2 selects ASC # 3 for packet data transmission on the HS-PRACH. This is related to configured the new transmission method for avoiding a collision with the following parameters ^I.:
• - Transmission Frame Length (TFL) = 6
• - Transmission Start Time (TST) = 6
• - Transmission Start Time Probability (TSTP) = {1/6, 1/6, 1/6, 1/6, 1/6, 1/6}
• - The "Constant delay" parameter is configured with 3 time slots.

In 5 the transmission diagram for the two terminals UE1, UE2 is shown depending on the respective transmission frame lengths. Both terminals start the transmission of their HS-PRACH message part in AS # 1. Within two frames, Terminal 1 sends its data packets P11, P12 and P13 in AS No = 2, AS No = 7 and AS No = 12. Terminal 2 sends its data packets P21 and P22 in AS No = 2 and AS No = 10.

In dependence the transmission times of the HS-PRACH news section are calculated the terminals the respective transmission intervals for the corresponding HS-SCCPCH according to the formulas:

Terminal 1 has the following Values:

• 1. AS_Nomin mod 15 = 2 + ceil {(4·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 8 mod 15 = 8
• 2. AS_Nomax mod 15 = 2 + ceil {(6·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 10 mod 15 = 10

For data package P11:

• 1. AS_Nomin mod 15 = 2 + ceil {(4 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 8 mod 15 = 8
• Second AS_Nomax mod 15 = 2 + ceil {(6 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 10 mod 15 = 10

• 3. AS_Nomin mod 15 = 7 + ceil {(4·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 13 mod 15 = 13.
• 4. AS_Nomax mod 15 = 7 + ceil {(6·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 15 mod 15 = 0

For data package P12:

• Third AS_Nomin mod 15 = 7 + ceil {(4 x 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 13 mod 15 = 13.
• 4th AS_Nomax mod 15 = 7 + ceil {(6 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 15 mod 15 = 0

• 1. AS_Nomin mod 15 = 12 + ceil {(4·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 18 mod 15 = 3
• 2. AS_Nomax mod 15 = 12 + ceil {(6·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 20 mod 15 = 5

For data package P13:

• 1. AS_Nomin mod 15 = 12 + ceil {(4 x 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 18 mod 15 = 3
• Second AS_Nomax mod 15 = 12 + ceil {(6 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 20 mod 15 = 5

Terminal 2 has the following Values:

• 1. AS_Nomin mod 15 = 2 + ceil {(4·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 8 mod 15 = 8
• 2. AS_Nomax mod 15 = 2 + ceil {(6·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 10 mod 15 = 10

For data package P21:

• 1. AS_Nomin mod 15 = 2 + ceil {(4 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 8 mod 15 = 8
• Second AS_Nomax mod 15 = 2 + ceil {(6 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 10 mod 15 = 10

• 1. AS_Nomin mod 15 = 10 + ceil {(4·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 16 mod 15 = 1
• 2. AS_Nomax mod 15 = 10 + ceil {(6·2 Zeitschlitze)/2 Zeitschlitze + 3 Zeitschlitze/2 Zeitschlitze} = 18 mod 15 = 3

For data package P22:

• 1. AS_Nomin mod 15 = 10 + ceil {(4 x 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 16 mod 15 = 1
• 2.AS_Nomax mod 15 = 10 + ceil {(6 · 2 time slots) / 2 time slots + 3 time slots / 2 time slots} = 18 mod 15 = 3

The Terminals can based on the calculated time offsets for the HS-SCCPCH according to their recipient to adjust. Conversely, the communication system BS can be received of the respective HS-PRACH message part the send interval for the correspond Calculate HS-SCCPCHs. The real one The communication system determines the time of transmission within this time interval based on data priority, the amount of data and / or the number of terminals using the same Selected HS-SCCPCH.

Abbreviations

• AC Access Class
• ACK Acknowledgment
• AICH Acquisition Indicator Channel
• AM Acknowledged Mode
• ARQ Automatic Repeat Request
• AS Access slot
• ASC Access Service Class
• BCH broadcast channel
• BMC broadcast / multicast control
• CCCH Common Control Channel
• CDMA Code Division Multiple Access
• CPICH Common Pilot Channel
• DCCH Dedicated Control Channel
• DL downlink
• DTCH Dedicated Traffic Channel
• FACH Forward Access Channel
• FDD Frequency Division Duplex
• HS-FACH High Speed FACH
• HS-PRACH High Speed PRACH
• HS-RACH High Speed RACH
• HS-SCCPCH High Speed S-CCPCH
• IMSI International Mobile Subscriber Identity
• kbps kilo bits per second
• MAC Medium Access Control
• NACK Negative Acknowledgment
• OVSF Orthogonal Variable Spreading Factor
• P-CCPCH Primary Common Control Physical Channel
• PDCP Packet Data Convergence Protocol
• PHY physical layer
• PRACH Physical Random Access Channel
• RACH Random Access Channel
• RLC Radio Link Control
• RNC Radio Network Controller
• RRC Radio Resource Control
• S-CCPCH Secondary Common Control Physical Channel
• SF spreading factor
• SFN system frame number
• SIB System Information Block
• TFCS Transport Format Combination Set
• TFL transmission frame length
• TFS Transport Format Set
• TM Transparent Mode
• TST Transmission Start Time
• TSTP Transmission Start Time Probability
• TTI transmission time interval
• TX Transmit
• UE user equipment
• UM Unacknowledged fashion
• UMTS Universal Mobile Telecommunications System
• U-RNTI UTRAN Radio Network Temporary Identity
• UTRAN UMTS Terrestrial Radio Access Network

Claims (8)

Method for the transmission of data packets between at least one terminal and a base station via radio channels provided for several terminals in a cellular communication system, in which the data packets for transmission are divided into transmission frames which are divided into at least one time slot, and the data in each time slot is a message part (HS-PRACH NT) and a preamble part, - wherein in a radio cell of the communication system a number M of common uplink channels (HS-PRACH1, HS-PRACH2) and a number N of common downlink channels (HS-SCCPCH1, HS -SCCPCH2) is provided, The terminal (UE) selects a common uplink channel (HS-PRACH1, HS-PRACH2) from the set of common uplink channels (HS-PRACH1, HS-PRACH2), the terminal after a successful transmission of the preamble part begins to send data packets in an access time slot (AS) defined by the uplink channel (HS-PRACH1, HS-PRACH2), the base station (BS) for each received data packet via a common downlink channel (HS-SCCPCH1, HS-SCCPCH2) sends an acknowledgment (ACK, NACK, 0) to the terminal (UE) at a transmission time after a constant time period, whereby this transmission time is specified as a time interval which is from the transmission time of the message part (HS-PRACH NT), - the transmission frame length (TTI) of the common uplink channel (HS-PRACH1, HS-PRACH2), - a minimum and a maximum transmission specified by the communication system frame length, - a minimum and maximum time deviation (TO _{min / max} ) between an uplink transmission and a downlink transmission, - whereby the base station also selects the downlink by the choice of the common uplink channel (HS-PRACH1, HS-PRACH2) Channel (HS-SCCPCH1, HS-SCCPCH2). The method of claim 1, wherein it is. Communication system around a working according to the UMTS-FDD mode Communication system. The method of claim 1 or 2, which is at the time interval around one determined by the selected uplink channel Access time slot (AS) acts. Method according to one of the preceding claims, which is equal to the number M of common uplink channels the number of common downlink channels in the Radio cell is. Method according to one of the preceding claims, the smaller the number M of common uplink channels or greater than the number N of common downlink channels in the radio cell and so is an uplink channel assigned multiple downlink channels are or vice versa. Terminal with one transmitter / receiver unit and one Processor unit used to carry out a method according to a of claims 1 to 5 is suitable. Base station with a transmitter / receiver unit and a processor unit which is used to carry out a method according to a of claims 1 to 6 is suitable. Communication system with a terminal according to claim 6 and a base station according to claim 7.